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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for Motorola/Freescale IMX serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Author: Sascha Hauer <sascha@saschahauer.de>
8 * Copyright (C) 2004 Pengutronix
9 */
10
11#include <linux/module.h>
12#include <linux/ioport.h>
13#include <linux/init.h>
14#include <linux/console.h>
15#include <linux/sysrq.h>
16#include <linux/platform_device.h>
17#include <linux/tty.h>
18#include <linux/tty_flip.h>
19#include <linux/serial_core.h>
20#include <linux/serial.h>
21#include <linux/clk.h>
22#include <linux/delay.h>
23#include <linux/ktime.h>
24#include <linux/pinctrl/consumer.h>
25#include <linux/rational.h>
26#include <linux/slab.h>
27#include <linux/of.h>
28#include <linux/of_device.h>
29#include <linux/io.h>
30#include <linux/dma-mapping.h>
31
32#include <asm/irq.h>
33#include <linux/platform_data/dma-imx.h>
34
35#include "serial_mctrl_gpio.h"
36
37/* Register definitions */
38#define URXD0 0x0 /* Receiver Register */
39#define URTX0 0x40 /* Transmitter Register */
40#define UCR1 0x80 /* Control Register 1 */
41#define UCR2 0x84 /* Control Register 2 */
42#define UCR3 0x88 /* Control Register 3 */
43#define UCR4 0x8c /* Control Register 4 */
44#define UFCR 0x90 /* FIFO Control Register */
45#define USR1 0x94 /* Status Register 1 */
46#define USR2 0x98 /* Status Register 2 */
47#define UESC 0x9c /* Escape Character Register */
48#define UTIM 0xa0 /* Escape Timer Register */
49#define UBIR 0xa4 /* BRM Incremental Register */
50#define UBMR 0xa8 /* BRM Modulator Register */
51#define UBRC 0xac /* Baud Rate Count Register */
52#define IMX21_ONEMS 0xb0 /* One Millisecond register */
53#define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
54#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
55
56/* UART Control Register Bit Fields.*/
57#define URXD_DUMMY_READ (1<<16)
58#define URXD_CHARRDY (1<<15)
59#define URXD_ERR (1<<14)
60#define URXD_OVRRUN (1<<13)
61#define URXD_FRMERR (1<<12)
62#define URXD_BRK (1<<11)
63#define URXD_PRERR (1<<10)
64#define URXD_RX_DATA (0xFF<<0)
65#define UCR1_ADEN (1<<15) /* Auto detect interrupt */
66#define UCR1_ADBR (1<<14) /* Auto detect baud rate */
67#define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
68#define UCR1_IDEN (1<<12) /* Idle condition interrupt */
69#define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
70#define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
71#define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */
72#define UCR1_IREN (1<<7) /* Infrared interface enable */
73#define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
74#define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
75#define UCR1_SNDBRK (1<<4) /* Send break */
76#define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */
77#define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
78#define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
79#define UCR1_DOZE (1<<1) /* Doze */
80#define UCR1_UARTEN (1<<0) /* UART enabled */
81#define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
82#define UCR2_IRTS (1<<14) /* Ignore RTS pin */
83#define UCR2_CTSC (1<<13) /* CTS pin control */
84#define UCR2_CTS (1<<12) /* Clear to send */
85#define UCR2_ESCEN (1<<11) /* Escape enable */
86#define UCR2_PREN (1<<8) /* Parity enable */
87#define UCR2_PROE (1<<7) /* Parity odd/even */
88#define UCR2_STPB (1<<6) /* Stop */
89#define UCR2_WS (1<<5) /* Word size */
90#define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
91#define UCR2_ATEN (1<<3) /* Aging Timer Enable */
92#define UCR2_TXEN (1<<2) /* Transmitter enabled */
93#define UCR2_RXEN (1<<1) /* Receiver enabled */
94#define UCR2_SRST (1<<0) /* SW reset */
95#define UCR3_DTREN (1<<13) /* DTR interrupt enable */
96#define UCR3_PARERREN (1<<12) /* Parity enable */
97#define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
98#define UCR3_DSR (1<<10) /* Data set ready */
99#define UCR3_DCD (1<<9) /* Data carrier detect */
100#define UCR3_RI (1<<8) /* Ring indicator */
101#define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
102#define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
103#define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
104#define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
105#define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
106#define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
107#define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
108#define UCR3_BPEN (1<<0) /* Preset registers enable */
109#define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
110#define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
111#define UCR4_INVR (1<<9) /* Inverted infrared reception */
112#define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
113#define UCR4_WKEN (1<<7) /* Wake interrupt enable */
114#define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
115#define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
116#define UCR4_IRSC (1<<5) /* IR special case */
117#define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
118#define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
119#define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
120#define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
121#define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
122#define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
123#define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
124#define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
125#define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
126#define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
127#define USR1_RTSS (1<<14) /* RTS pin status */
128#define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
129#define USR1_RTSD (1<<12) /* RTS delta */
130#define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
131#define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
132#define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
133#define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
134#define USR1_DTRD (1<<7) /* DTR Delta */
135#define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
136#define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
137#define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
138#define USR2_ADET (1<<15) /* Auto baud rate detect complete */
139#define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
140#define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
141#define USR2_IDLE (1<<12) /* Idle condition */
142#define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
143#define USR2_RIIN (1<<9) /* Ring Indicator Input */
144#define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
145#define USR2_WAKE (1<<7) /* Wake */
146#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
147#define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
148#define USR2_TXDC (1<<3) /* Transmitter complete */
149#define USR2_BRCD (1<<2) /* Break condition */
150#define USR2_ORE (1<<1) /* Overrun error */
151#define USR2_RDR (1<<0) /* Recv data ready */
152#define UTS_FRCPERR (1<<13) /* Force parity error */
153#define UTS_LOOP (1<<12) /* Loop tx and rx */
154#define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
155#define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
156#define UTS_TXFULL (1<<4) /* TxFIFO full */
157#define UTS_RXFULL (1<<3) /* RxFIFO full */
158#define UTS_SOFTRST (1<<0) /* Software reset */
159
160/* We've been assigned a range on the "Low-density serial ports" major */
161#define SERIAL_IMX_MAJOR 207
162#define MINOR_START 16
163#define DEV_NAME "ttymxc"
164
165/*
166 * This determines how often we check the modem status signals
167 * for any change. They generally aren't connected to an IRQ
168 * so we have to poll them. We also check immediately before
169 * filling the TX fifo incase CTS has been dropped.
170 */
171#define MCTRL_TIMEOUT (250*HZ/1000)
172
173#define DRIVER_NAME "IMX-uart"
174
175#define UART_NR 8
176
177/* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
178enum imx_uart_type {
179 IMX1_UART,
180 IMX21_UART,
181 IMX53_UART,
182 IMX6Q_UART,
183};
184
185/* device type dependent stuff */
186struct imx_uart_data {
187 unsigned uts_reg;
188 enum imx_uart_type devtype;
189};
190
191enum imx_tx_state {
192 OFF,
193 WAIT_AFTER_RTS,
194 SEND,
195 WAIT_AFTER_SEND,
196};
197
198struct imx_port {
199 struct uart_port port;
200 struct timer_list timer;
201 unsigned int old_status;
202 unsigned int have_rtscts:1;
203 unsigned int have_rtsgpio:1;
204 unsigned int dte_mode:1;
205 unsigned int inverted_tx:1;
206 unsigned int inverted_rx:1;
207 struct clk *clk_ipg;
208 struct clk *clk_per;
209 const struct imx_uart_data *devdata;
210
211 struct mctrl_gpios *gpios;
212
213 /* shadow registers */
214 unsigned int ucr1;
215 unsigned int ucr2;
216 unsigned int ucr3;
217 unsigned int ucr4;
218 unsigned int ufcr;
219
220 /* DMA fields */
221 unsigned int dma_is_enabled:1;
222 unsigned int dma_is_rxing:1;
223 unsigned int dma_is_txing:1;
224 struct dma_chan *dma_chan_rx, *dma_chan_tx;
225 struct scatterlist rx_sgl, tx_sgl[2];
226 void *rx_buf;
227 struct circ_buf rx_ring;
228 unsigned int rx_buf_size;
229 unsigned int rx_period_length;
230 unsigned int rx_periods;
231 dma_cookie_t rx_cookie;
232 unsigned int tx_bytes;
233 unsigned int dma_tx_nents;
234 unsigned int saved_reg[10];
235 bool context_saved;
236
237 enum imx_tx_state tx_state;
238 struct hrtimer trigger_start_tx;
239 struct hrtimer trigger_stop_tx;
240};
241
242struct imx_port_ucrs {
243 unsigned int ucr1;
244 unsigned int ucr2;
245 unsigned int ucr3;
246};
247
248static struct imx_uart_data imx_uart_devdata[] = {
249 [IMX1_UART] = {
250 .uts_reg = IMX1_UTS,
251 .devtype = IMX1_UART,
252 },
253 [IMX21_UART] = {
254 .uts_reg = IMX21_UTS,
255 .devtype = IMX21_UART,
256 },
257 [IMX53_UART] = {
258 .uts_reg = IMX21_UTS,
259 .devtype = IMX53_UART,
260 },
261 [IMX6Q_UART] = {
262 .uts_reg = IMX21_UTS,
263 .devtype = IMX6Q_UART,
264 },
265};
266
267static const struct of_device_id imx_uart_dt_ids[] = {
268 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
269 { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
270 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
271 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
272 { /* sentinel */ }
273};
274MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
275
276static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
277{
278 switch (offset) {
279 case UCR1:
280 sport->ucr1 = val;
281 break;
282 case UCR2:
283 sport->ucr2 = val;
284 break;
285 case UCR3:
286 sport->ucr3 = val;
287 break;
288 case UCR4:
289 sport->ucr4 = val;
290 break;
291 case UFCR:
292 sport->ufcr = val;
293 break;
294 default:
295 break;
296 }
297 writel(val, sport->port.membase + offset);
298}
299
300static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
301{
302 switch (offset) {
303 case UCR1:
304 return sport->ucr1;
305 break;
306 case UCR2:
307 /*
308 * UCR2_SRST is the only bit in the cached registers that might
309 * differ from the value that was last written. As it only
310 * automatically becomes one after being cleared, reread
311 * conditionally.
312 */
313 if (!(sport->ucr2 & UCR2_SRST))
314 sport->ucr2 = readl(sport->port.membase + offset);
315 return sport->ucr2;
316 break;
317 case UCR3:
318 return sport->ucr3;
319 break;
320 case UCR4:
321 return sport->ucr4;
322 break;
323 case UFCR:
324 return sport->ufcr;
325 break;
326 default:
327 return readl(sport->port.membase + offset);
328 }
329}
330
331static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
332{
333 return sport->devdata->uts_reg;
334}
335
336static inline int imx_uart_is_imx1(struct imx_port *sport)
337{
338 return sport->devdata->devtype == IMX1_UART;
339}
340
341static inline int imx_uart_is_imx21(struct imx_port *sport)
342{
343 return sport->devdata->devtype == IMX21_UART;
344}
345
346static inline int imx_uart_is_imx53(struct imx_port *sport)
347{
348 return sport->devdata->devtype == IMX53_UART;
349}
350
351static inline int imx_uart_is_imx6q(struct imx_port *sport)
352{
353 return sport->devdata->devtype == IMX6Q_UART;
354}
355/*
356 * Save and restore functions for UCR1, UCR2 and UCR3 registers
357 */
358#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
359static void imx_uart_ucrs_save(struct imx_port *sport,
360 struct imx_port_ucrs *ucr)
361{
362 /* save control registers */
363 ucr->ucr1 = imx_uart_readl(sport, UCR1);
364 ucr->ucr2 = imx_uart_readl(sport, UCR2);
365 ucr->ucr3 = imx_uart_readl(sport, UCR3);
366}
367
368static void imx_uart_ucrs_restore(struct imx_port *sport,
369 struct imx_port_ucrs *ucr)
370{
371 /* restore control registers */
372 imx_uart_writel(sport, ucr->ucr1, UCR1);
373 imx_uart_writel(sport, ucr->ucr2, UCR2);
374 imx_uart_writel(sport, ucr->ucr3, UCR3);
375}
376#endif
377
378/* called with port.lock taken and irqs caller dependent */
379static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
380{
381 *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
382
383 sport->port.mctrl |= TIOCM_RTS;
384 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
385}
386
387/* called with port.lock taken and irqs caller dependent */
388static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
389{
390 *ucr2 &= ~UCR2_CTSC;
391 *ucr2 |= UCR2_CTS;
392
393 sport->port.mctrl &= ~TIOCM_RTS;
394 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
395}
396
397static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
398{
399 hrtimer_start(hrt, ms_to_ktime(msec), HRTIMER_MODE_REL);
400}
401
402/* called with port.lock taken and irqs off */
403static void imx_uart_start_rx(struct uart_port *port)
404{
405 struct imx_port *sport = (struct imx_port *)port;
406 unsigned int ucr1, ucr2;
407
408 ucr1 = imx_uart_readl(sport, UCR1);
409 ucr2 = imx_uart_readl(sport, UCR2);
410
411 ucr2 |= UCR2_RXEN;
412
413 if (sport->dma_is_enabled) {
414 ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
415 } else {
416 ucr1 |= UCR1_RRDYEN;
417 ucr2 |= UCR2_ATEN;
418 }
419
420 /* Write UCR2 first as it includes RXEN */
421 imx_uart_writel(sport, ucr2, UCR2);
422 imx_uart_writel(sport, ucr1, UCR1);
423}
424
425/* called with port.lock taken and irqs off */
426static void imx_uart_stop_tx(struct uart_port *port)
427{
428 struct imx_port *sport = (struct imx_port *)port;
429 u32 ucr1, ucr4, usr2;
430
431 if (sport->tx_state == OFF)
432 return;
433
434 /*
435 * We are maybe in the SMP context, so if the DMA TX thread is running
436 * on other cpu, we have to wait for it to finish.
437 */
438 if (sport->dma_is_txing)
439 return;
440
441 ucr1 = imx_uart_readl(sport, UCR1);
442 imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
443
444 usr2 = imx_uart_readl(sport, USR2);
445 if (!(usr2 & USR2_TXDC)) {
446 /* The shifter is still busy, so retry once TC triggers */
447 return;
448 }
449
450 ucr4 = imx_uart_readl(sport, UCR4);
451 ucr4 &= ~UCR4_TCEN;
452 imx_uart_writel(sport, ucr4, UCR4);
453
454 /* in rs485 mode disable transmitter */
455 if (port->rs485.flags & SER_RS485_ENABLED) {
456 if (sport->tx_state == SEND) {
457 sport->tx_state = WAIT_AFTER_SEND;
458 start_hrtimer_ms(&sport->trigger_stop_tx,
459 port->rs485.delay_rts_after_send);
460 return;
461 }
462
463 if (sport->tx_state == WAIT_AFTER_RTS ||
464 sport->tx_state == WAIT_AFTER_SEND) {
465 u32 ucr2;
466
467 hrtimer_try_to_cancel(&sport->trigger_start_tx);
468
469 ucr2 = imx_uart_readl(sport, UCR2);
470 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
471 imx_uart_rts_active(sport, &ucr2);
472 else
473 imx_uart_rts_inactive(sport, &ucr2);
474 imx_uart_writel(sport, ucr2, UCR2);
475
476 imx_uart_start_rx(port);
477
478 sport->tx_state = OFF;
479 }
480 } else {
481 sport->tx_state = OFF;
482 }
483}
484
485/* called with port.lock taken and irqs off */
486static void imx_uart_stop_rx(struct uart_port *port)
487{
488 struct imx_port *sport = (struct imx_port *)port;
489 u32 ucr1, ucr2;
490
491 ucr1 = imx_uart_readl(sport, UCR1);
492 ucr2 = imx_uart_readl(sport, UCR2);
493
494 if (sport->dma_is_enabled) {
495 ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
496 } else {
497 ucr1 &= ~UCR1_RRDYEN;
498 ucr2 &= ~UCR2_ATEN;
499 }
500 imx_uart_writel(sport, ucr1, UCR1);
501
502 ucr2 &= ~UCR2_RXEN;
503 imx_uart_writel(sport, ucr2, UCR2);
504}
505
506/* called with port.lock taken and irqs off */
507static void imx_uart_enable_ms(struct uart_port *port)
508{
509 struct imx_port *sport = (struct imx_port *)port;
510
511 mod_timer(&sport->timer, jiffies);
512
513 mctrl_gpio_enable_ms(sport->gpios);
514}
515
516static void imx_uart_dma_tx(struct imx_port *sport);
517
518/* called with port.lock taken and irqs off */
519static inline void imx_uart_transmit_buffer(struct imx_port *sport)
520{
521 struct circ_buf *xmit = &sport->port.state->xmit;
522
523 if (sport->port.x_char) {
524 /* Send next char */
525 imx_uart_writel(sport, sport->port.x_char, URTX0);
526 sport->port.icount.tx++;
527 sport->port.x_char = 0;
528 return;
529 }
530
531 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
532 imx_uart_stop_tx(&sport->port);
533 return;
534 }
535
536 if (sport->dma_is_enabled) {
537 u32 ucr1;
538 /*
539 * We've just sent a X-char Ensure the TX DMA is enabled
540 * and the TX IRQ is disabled.
541 **/
542 ucr1 = imx_uart_readl(sport, UCR1);
543 ucr1 &= ~UCR1_TRDYEN;
544 if (sport->dma_is_txing) {
545 ucr1 |= UCR1_TXDMAEN;
546 imx_uart_writel(sport, ucr1, UCR1);
547 } else {
548 imx_uart_writel(sport, ucr1, UCR1);
549 imx_uart_dma_tx(sport);
550 }
551
552 return;
553 }
554
555 while (!uart_circ_empty(xmit) &&
556 !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
557 /* send xmit->buf[xmit->tail]
558 * out the port here */
559 imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
560 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
561 sport->port.icount.tx++;
562 }
563
564 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
565 uart_write_wakeup(&sport->port);
566
567 if (uart_circ_empty(xmit))
568 imx_uart_stop_tx(&sport->port);
569}
570
571static void imx_uart_dma_tx_callback(void *data)
572{
573 struct imx_port *sport = data;
574 struct scatterlist *sgl = &sport->tx_sgl[0];
575 struct circ_buf *xmit = &sport->port.state->xmit;
576 unsigned long flags;
577 u32 ucr1;
578
579 spin_lock_irqsave(&sport->port.lock, flags);
580
581 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
582
583 ucr1 = imx_uart_readl(sport, UCR1);
584 ucr1 &= ~UCR1_TXDMAEN;
585 imx_uart_writel(sport, ucr1, UCR1);
586
587 /* update the stat */
588 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
589 sport->port.icount.tx += sport->tx_bytes;
590
591 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
592
593 sport->dma_is_txing = 0;
594
595 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
596 uart_write_wakeup(&sport->port);
597
598 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
599 imx_uart_dma_tx(sport);
600 else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
601 u32 ucr4 = imx_uart_readl(sport, UCR4);
602 ucr4 |= UCR4_TCEN;
603 imx_uart_writel(sport, ucr4, UCR4);
604 }
605
606 spin_unlock_irqrestore(&sport->port.lock, flags);
607}
608
609/* called with port.lock taken and irqs off */
610static void imx_uart_dma_tx(struct imx_port *sport)
611{
612 struct circ_buf *xmit = &sport->port.state->xmit;
613 struct scatterlist *sgl = sport->tx_sgl;
614 struct dma_async_tx_descriptor *desc;
615 struct dma_chan *chan = sport->dma_chan_tx;
616 struct device *dev = sport->port.dev;
617 u32 ucr1, ucr4;
618 int ret;
619
620 if (sport->dma_is_txing)
621 return;
622
623 ucr4 = imx_uart_readl(sport, UCR4);
624 ucr4 &= ~UCR4_TCEN;
625 imx_uart_writel(sport, ucr4, UCR4);
626
627 sport->tx_bytes = uart_circ_chars_pending(xmit);
628
629 if (xmit->tail < xmit->head || xmit->head == 0) {
630 sport->dma_tx_nents = 1;
631 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
632 } else {
633 sport->dma_tx_nents = 2;
634 sg_init_table(sgl, 2);
635 sg_set_buf(sgl, xmit->buf + xmit->tail,
636 UART_XMIT_SIZE - xmit->tail);
637 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
638 }
639
640 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
641 if (ret == 0) {
642 dev_err(dev, "DMA mapping error for TX.\n");
643 return;
644 }
645 desc = dmaengine_prep_slave_sg(chan, sgl, ret,
646 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
647 if (!desc) {
648 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
649 DMA_TO_DEVICE);
650 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
651 return;
652 }
653 desc->callback = imx_uart_dma_tx_callback;
654 desc->callback_param = sport;
655
656 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
657 uart_circ_chars_pending(xmit));
658
659 ucr1 = imx_uart_readl(sport, UCR1);
660 ucr1 |= UCR1_TXDMAEN;
661 imx_uart_writel(sport, ucr1, UCR1);
662
663 /* fire it */
664 sport->dma_is_txing = 1;
665 dmaengine_submit(desc);
666 dma_async_issue_pending(chan);
667 return;
668}
669
670/* called with port.lock taken and irqs off */
671static void imx_uart_start_tx(struct uart_port *port)
672{
673 struct imx_port *sport = (struct imx_port *)port;
674 u32 ucr1;
675
676 if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
677 return;
678
679 /*
680 * We cannot simply do nothing here if sport->tx_state == SEND already
681 * because UCR1_TXMPTYEN might already have been cleared in
682 * imx_uart_stop_tx(), but tx_state is still SEND.
683 */
684
685 if (port->rs485.flags & SER_RS485_ENABLED) {
686 if (sport->tx_state == OFF) {
687 u32 ucr2 = imx_uart_readl(sport, UCR2);
688 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
689 imx_uart_rts_active(sport, &ucr2);
690 else
691 imx_uart_rts_inactive(sport, &ucr2);
692 imx_uart_writel(sport, ucr2, UCR2);
693
694 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
695 imx_uart_stop_rx(port);
696
697 sport->tx_state = WAIT_AFTER_RTS;
698 start_hrtimer_ms(&sport->trigger_start_tx,
699 port->rs485.delay_rts_before_send);
700 return;
701 }
702
703 if (sport->tx_state == WAIT_AFTER_SEND
704 || sport->tx_state == WAIT_AFTER_RTS) {
705
706 hrtimer_try_to_cancel(&sport->trigger_stop_tx);
707
708 /*
709 * Enable transmitter and shifter empty irq only if DMA
710 * is off. In the DMA case this is done in the
711 * tx-callback.
712 */
713 if (!sport->dma_is_enabled) {
714 u32 ucr4 = imx_uart_readl(sport, UCR4);
715 ucr4 |= UCR4_TCEN;
716 imx_uart_writel(sport, ucr4, UCR4);
717 }
718
719 sport->tx_state = SEND;
720 }
721 } else {
722 sport->tx_state = SEND;
723 }
724
725 if (!sport->dma_is_enabled) {
726 ucr1 = imx_uart_readl(sport, UCR1);
727 imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1);
728 }
729
730 if (sport->dma_is_enabled) {
731 if (sport->port.x_char) {
732 /* We have X-char to send, so enable TX IRQ and
733 * disable TX DMA to let TX interrupt to send X-char */
734 ucr1 = imx_uart_readl(sport, UCR1);
735 ucr1 &= ~UCR1_TXDMAEN;
736 ucr1 |= UCR1_TRDYEN;
737 imx_uart_writel(sport, ucr1, UCR1);
738 return;
739 }
740
741 if (!uart_circ_empty(&port->state->xmit) &&
742 !uart_tx_stopped(port))
743 imx_uart_dma_tx(sport);
744 return;
745 }
746}
747
748static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id)
749{
750 struct imx_port *sport = dev_id;
751 u32 usr1;
752
753 imx_uart_writel(sport, USR1_RTSD, USR1);
754 usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
755 uart_handle_cts_change(&sport->port, !!usr1);
756 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
757
758 return IRQ_HANDLED;
759}
760
761static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
762{
763 struct imx_port *sport = dev_id;
764 irqreturn_t ret;
765
766 spin_lock(&sport->port.lock);
767
768 ret = __imx_uart_rtsint(irq, dev_id);
769
770 spin_unlock(&sport->port.lock);
771
772 return ret;
773}
774
775static irqreturn_t imx_uart_txint(int irq, void *dev_id)
776{
777 struct imx_port *sport = dev_id;
778
779 spin_lock(&sport->port.lock);
780 imx_uart_transmit_buffer(sport);
781 spin_unlock(&sport->port.lock);
782 return IRQ_HANDLED;
783}
784
785static irqreturn_t __imx_uart_rxint(int irq, void *dev_id)
786{
787 struct imx_port *sport = dev_id;
788 unsigned int rx, flg, ignored = 0;
789 struct tty_port *port = &sport->port.state->port;
790
791 while (imx_uart_readl(sport, USR2) & USR2_RDR) {
792 u32 usr2;
793
794 flg = TTY_NORMAL;
795 sport->port.icount.rx++;
796
797 rx = imx_uart_readl(sport, URXD0);
798
799 usr2 = imx_uart_readl(sport, USR2);
800 if (usr2 & USR2_BRCD) {
801 imx_uart_writel(sport, USR2_BRCD, USR2);
802 if (uart_handle_break(&sport->port))
803 continue;
804 }
805
806 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
807 continue;
808
809 if (unlikely(rx & URXD_ERR)) {
810 if (rx & URXD_BRK)
811 sport->port.icount.brk++;
812 else if (rx & URXD_PRERR)
813 sport->port.icount.parity++;
814 else if (rx & URXD_FRMERR)
815 sport->port.icount.frame++;
816 if (rx & URXD_OVRRUN)
817 sport->port.icount.overrun++;
818
819 if (rx & sport->port.ignore_status_mask) {
820 if (++ignored > 100)
821 goto out;
822 continue;
823 }
824
825 rx &= (sport->port.read_status_mask | 0xFF);
826
827 if (rx & URXD_BRK)
828 flg = TTY_BREAK;
829 else if (rx & URXD_PRERR)
830 flg = TTY_PARITY;
831 else if (rx & URXD_FRMERR)
832 flg = TTY_FRAME;
833 if (rx & URXD_OVRRUN)
834 flg = TTY_OVERRUN;
835
836 sport->port.sysrq = 0;
837 }
838
839 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
840 goto out;
841
842 if (tty_insert_flip_char(port, rx, flg) == 0)
843 sport->port.icount.buf_overrun++;
844 }
845
846out:
847 tty_flip_buffer_push(port);
848
849 return IRQ_HANDLED;
850}
851
852static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
853{
854 struct imx_port *sport = dev_id;
855 irqreturn_t ret;
856
857 spin_lock(&sport->port.lock);
858
859 ret = __imx_uart_rxint(irq, dev_id);
860
861 spin_unlock(&sport->port.lock);
862
863 return ret;
864}
865
866static void imx_uart_clear_rx_errors(struct imx_port *sport);
867
868/*
869 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
870 */
871static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
872{
873 unsigned int tmp = TIOCM_DSR;
874 unsigned usr1 = imx_uart_readl(sport, USR1);
875 unsigned usr2 = imx_uart_readl(sport, USR2);
876
877 if (usr1 & USR1_RTSS)
878 tmp |= TIOCM_CTS;
879
880 /* in DCE mode DCDIN is always 0 */
881 if (!(usr2 & USR2_DCDIN))
882 tmp |= TIOCM_CAR;
883
884 if (sport->dte_mode)
885 if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
886 tmp |= TIOCM_RI;
887
888 return tmp;
889}
890
891/*
892 * Handle any change of modem status signal since we were last called.
893 */
894static void imx_uart_mctrl_check(struct imx_port *sport)
895{
896 unsigned int status, changed;
897
898 status = imx_uart_get_hwmctrl(sport);
899 changed = status ^ sport->old_status;
900
901 if (changed == 0)
902 return;
903
904 sport->old_status = status;
905
906 if (changed & TIOCM_RI && status & TIOCM_RI)
907 sport->port.icount.rng++;
908 if (changed & TIOCM_DSR)
909 sport->port.icount.dsr++;
910 if (changed & TIOCM_CAR)
911 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
912 if (changed & TIOCM_CTS)
913 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
914
915 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
916}
917
918static irqreturn_t imx_uart_int(int irq, void *dev_id)
919{
920 struct imx_port *sport = dev_id;
921 unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
922 irqreturn_t ret = IRQ_NONE;
923
924 spin_lock(&sport->port.lock);
925
926 usr1 = imx_uart_readl(sport, USR1);
927 usr2 = imx_uart_readl(sport, USR2);
928 ucr1 = imx_uart_readl(sport, UCR1);
929 ucr2 = imx_uart_readl(sport, UCR2);
930 ucr3 = imx_uart_readl(sport, UCR3);
931 ucr4 = imx_uart_readl(sport, UCR4);
932
933 /*
934 * Even if a condition is true that can trigger an irq only handle it if
935 * the respective irq source is enabled. This prevents some undesired
936 * actions, for example if a character that sits in the RX FIFO and that
937 * should be fetched via DMA is tried to be fetched using PIO. Or the
938 * receiver is currently off and so reading from URXD0 results in an
939 * exception. So just mask the (raw) status bits for disabled irqs.
940 */
941 if ((ucr1 & UCR1_RRDYEN) == 0)
942 usr1 &= ~USR1_RRDY;
943 if ((ucr2 & UCR2_ATEN) == 0)
944 usr1 &= ~USR1_AGTIM;
945 if ((ucr1 & UCR1_TRDYEN) == 0)
946 usr1 &= ~USR1_TRDY;
947 if ((ucr4 & UCR4_TCEN) == 0)
948 usr2 &= ~USR2_TXDC;
949 if ((ucr3 & UCR3_DTRDEN) == 0)
950 usr1 &= ~USR1_DTRD;
951 if ((ucr1 & UCR1_RTSDEN) == 0)
952 usr1 &= ~USR1_RTSD;
953 if ((ucr3 & UCR3_AWAKEN) == 0)
954 usr1 &= ~USR1_AWAKE;
955 if ((ucr4 & UCR4_OREN) == 0)
956 usr2 &= ~USR2_ORE;
957
958 if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
959 imx_uart_writel(sport, USR1_AGTIM, USR1);
960
961 __imx_uart_rxint(irq, dev_id);
962 ret = IRQ_HANDLED;
963 }
964
965 if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
966 imx_uart_transmit_buffer(sport);
967 ret = IRQ_HANDLED;
968 }
969
970 if (usr1 & USR1_DTRD) {
971 imx_uart_writel(sport, USR1_DTRD, USR1);
972
973 imx_uart_mctrl_check(sport);
974
975 ret = IRQ_HANDLED;
976 }
977
978 if (usr1 & USR1_RTSD) {
979 __imx_uart_rtsint(irq, dev_id);
980 ret = IRQ_HANDLED;
981 }
982
983 if (usr1 & USR1_AWAKE) {
984 imx_uart_writel(sport, USR1_AWAKE, USR1);
985 ret = IRQ_HANDLED;
986 }
987
988 if (usr2 & USR2_ORE) {
989 sport->port.icount.overrun++;
990 imx_uart_writel(sport, USR2_ORE, USR2);
991 ret = IRQ_HANDLED;
992 }
993
994 spin_unlock(&sport->port.lock);
995
996 return ret;
997}
998
999/*
1000 * Return TIOCSER_TEMT when transmitter is not busy.
1001 */
1002static unsigned int imx_uart_tx_empty(struct uart_port *port)
1003{
1004 struct imx_port *sport = (struct imx_port *)port;
1005 unsigned int ret;
1006
1007 ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
1008
1009 /* If the TX DMA is working, return 0. */
1010 if (sport->dma_is_txing)
1011 ret = 0;
1012
1013 return ret;
1014}
1015
1016/* called with port.lock taken and irqs off */
1017static unsigned int imx_uart_get_mctrl(struct uart_port *port)
1018{
1019 struct imx_port *sport = (struct imx_port *)port;
1020 unsigned int ret = imx_uart_get_hwmctrl(sport);
1021
1022 mctrl_gpio_get(sport->gpios, &ret);
1023
1024 return ret;
1025}
1026
1027/* called with port.lock taken and irqs off */
1028static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
1029{
1030 struct imx_port *sport = (struct imx_port *)port;
1031 u32 ucr3, uts;
1032
1033 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
1034 u32 ucr2;
1035
1036 /*
1037 * Turn off autoRTS if RTS is lowered and restore autoRTS
1038 * setting if RTS is raised.
1039 */
1040 ucr2 = imx_uart_readl(sport, UCR2);
1041 ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
1042 if (mctrl & TIOCM_RTS) {
1043 ucr2 |= UCR2_CTS;
1044 /*
1045 * UCR2_IRTS is unset if and only if the port is
1046 * configured for CRTSCTS, so we use inverted UCR2_IRTS
1047 * to get the state to restore to.
1048 */
1049 if (!(ucr2 & UCR2_IRTS))
1050 ucr2 |= UCR2_CTSC;
1051 }
1052 imx_uart_writel(sport, ucr2, UCR2);
1053 }
1054
1055 ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
1056 if (!(mctrl & TIOCM_DTR))
1057 ucr3 |= UCR3_DSR;
1058 imx_uart_writel(sport, ucr3, UCR3);
1059
1060 uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
1061 if (mctrl & TIOCM_LOOP)
1062 uts |= UTS_LOOP;
1063 imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
1064
1065 mctrl_gpio_set(sport->gpios, mctrl);
1066}
1067
1068/*
1069 * Interrupts always disabled.
1070 */
1071static void imx_uart_break_ctl(struct uart_port *port, int break_state)
1072{
1073 struct imx_port *sport = (struct imx_port *)port;
1074 unsigned long flags;
1075 u32 ucr1;
1076
1077 spin_lock_irqsave(&sport->port.lock, flags);
1078
1079 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
1080
1081 if (break_state != 0)
1082 ucr1 |= UCR1_SNDBRK;
1083
1084 imx_uart_writel(sport, ucr1, UCR1);
1085
1086 spin_unlock_irqrestore(&sport->port.lock, flags);
1087}
1088
1089/*
1090 * This is our per-port timeout handler, for checking the
1091 * modem status signals.
1092 */
1093static void imx_uart_timeout(struct timer_list *t)
1094{
1095 struct imx_port *sport = from_timer(sport, t, timer);
1096 unsigned long flags;
1097
1098 if (sport->port.state) {
1099 spin_lock_irqsave(&sport->port.lock, flags);
1100 imx_uart_mctrl_check(sport);
1101 spin_unlock_irqrestore(&sport->port.lock, flags);
1102
1103 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
1104 }
1105}
1106
1107/*
1108 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
1109 * [1] the RX DMA buffer is full.
1110 * [2] the aging timer expires
1111 *
1112 * Condition [2] is triggered when a character has been sitting in the FIFO
1113 * for at least 8 byte durations.
1114 */
1115static void imx_uart_dma_rx_callback(void *data)
1116{
1117 struct imx_port *sport = data;
1118 struct dma_chan *chan = sport->dma_chan_rx;
1119 struct scatterlist *sgl = &sport->rx_sgl;
1120 struct tty_port *port = &sport->port.state->port;
1121 struct dma_tx_state state;
1122 struct circ_buf *rx_ring = &sport->rx_ring;
1123 enum dma_status status;
1124 unsigned int w_bytes = 0;
1125 unsigned int r_bytes;
1126 unsigned int bd_size;
1127
1128 status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
1129
1130 if (status == DMA_ERROR) {
1131 imx_uart_clear_rx_errors(sport);
1132 return;
1133 }
1134
1135 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
1136
1137 /*
1138 * The state-residue variable represents the empty space
1139 * relative to the entire buffer. Taking this in consideration
1140 * the head is always calculated base on the buffer total
1141 * length - DMA transaction residue. The UART script from the
1142 * SDMA firmware will jump to the next buffer descriptor,
1143 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
1144 * Taking this in consideration the tail is always at the
1145 * beginning of the buffer descriptor that contains the head.
1146 */
1147
1148 /* Calculate the head */
1149 rx_ring->head = sg_dma_len(sgl) - state.residue;
1150
1151 /* Calculate the tail. */
1152 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1153 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1154
1155 if (rx_ring->head <= sg_dma_len(sgl) &&
1156 rx_ring->head > rx_ring->tail) {
1157
1158 /* Move data from tail to head */
1159 r_bytes = rx_ring->head - rx_ring->tail;
1160
1161 /* CPU claims ownership of RX DMA buffer */
1162 dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1163 DMA_FROM_DEVICE);
1164
1165 w_bytes = tty_insert_flip_string(port,
1166 sport->rx_buf + rx_ring->tail, r_bytes);
1167
1168 /* UART retrieves ownership of RX DMA buffer */
1169 dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1170 DMA_FROM_DEVICE);
1171
1172 if (w_bytes != r_bytes)
1173 sport->port.icount.buf_overrun++;
1174
1175 sport->port.icount.rx += w_bytes;
1176 } else {
1177 WARN_ON(rx_ring->head > sg_dma_len(sgl));
1178 WARN_ON(rx_ring->head <= rx_ring->tail);
1179 }
1180 }
1181
1182 if (w_bytes) {
1183 tty_flip_buffer_push(port);
1184 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1185 }
1186}
1187
1188static int imx_uart_start_rx_dma(struct imx_port *sport)
1189{
1190 struct scatterlist *sgl = &sport->rx_sgl;
1191 struct dma_chan *chan = sport->dma_chan_rx;
1192 struct device *dev = sport->port.dev;
1193 struct dma_async_tx_descriptor *desc;
1194 int ret;
1195
1196 sport->rx_ring.head = 0;
1197 sport->rx_ring.tail = 0;
1198
1199 sg_init_one(sgl, sport->rx_buf, sport->rx_buf_size);
1200 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1201 if (ret == 0) {
1202 dev_err(dev, "DMA mapping error for RX.\n");
1203 return -EINVAL;
1204 }
1205
1206 desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1207 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1208 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1209
1210 if (!desc) {
1211 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1212 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1213 return -EINVAL;
1214 }
1215 desc->callback = imx_uart_dma_rx_callback;
1216 desc->callback_param = sport;
1217
1218 dev_dbg(dev, "RX: prepare for the DMA.\n");
1219 sport->dma_is_rxing = 1;
1220 sport->rx_cookie = dmaengine_submit(desc);
1221 dma_async_issue_pending(chan);
1222 return 0;
1223}
1224
1225static void imx_uart_clear_rx_errors(struct imx_port *sport)
1226{
1227 struct tty_port *port = &sport->port.state->port;
1228 u32 usr1, usr2;
1229
1230 usr1 = imx_uart_readl(sport, USR1);
1231 usr2 = imx_uart_readl(sport, USR2);
1232
1233 if (usr2 & USR2_BRCD) {
1234 sport->port.icount.brk++;
1235 imx_uart_writel(sport, USR2_BRCD, USR2);
1236 uart_handle_break(&sport->port);
1237 if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
1238 sport->port.icount.buf_overrun++;
1239 tty_flip_buffer_push(port);
1240 } else {
1241 if (usr1 & USR1_FRAMERR) {
1242 sport->port.icount.frame++;
1243 imx_uart_writel(sport, USR1_FRAMERR, USR1);
1244 } else if (usr1 & USR1_PARITYERR) {
1245 sport->port.icount.parity++;
1246 imx_uart_writel(sport, USR1_PARITYERR, USR1);
1247 }
1248 }
1249
1250 if (usr2 & USR2_ORE) {
1251 sport->port.icount.overrun++;
1252 imx_uart_writel(sport, USR2_ORE, USR2);
1253 }
1254
1255}
1256
1257#define TXTL_DEFAULT 2 /* reset default */
1258#define RXTL_DEFAULT 1 /* reset default */
1259#define TXTL_DMA 8 /* DMA burst setting */
1260#define RXTL_DMA 9 /* DMA burst setting */
1261
1262static void imx_uart_setup_ufcr(struct imx_port *sport,
1263 unsigned char txwl, unsigned char rxwl)
1264{
1265 unsigned int val;
1266
1267 /* set receiver / transmitter trigger level */
1268 val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1269 val |= txwl << UFCR_TXTL_SHF | rxwl;
1270 imx_uart_writel(sport, val, UFCR);
1271}
1272
1273static void imx_uart_dma_exit(struct imx_port *sport)
1274{
1275 if (sport->dma_chan_rx) {
1276 dmaengine_terminate_sync(sport->dma_chan_rx);
1277 dma_release_channel(sport->dma_chan_rx);
1278 sport->dma_chan_rx = NULL;
1279 sport->rx_cookie = -EINVAL;
1280 kfree(sport->rx_buf);
1281 sport->rx_buf = NULL;
1282 }
1283
1284 if (sport->dma_chan_tx) {
1285 dmaengine_terminate_sync(sport->dma_chan_tx);
1286 dma_release_channel(sport->dma_chan_tx);
1287 sport->dma_chan_tx = NULL;
1288 }
1289}
1290
1291static int imx_uart_dma_init(struct imx_port *sport)
1292{
1293 struct dma_slave_config slave_config = {};
1294 struct device *dev = sport->port.dev;
1295 int ret;
1296
1297 /* Prepare for RX : */
1298 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1299 if (!sport->dma_chan_rx) {
1300 dev_dbg(dev, "cannot get the DMA channel.\n");
1301 ret = -EINVAL;
1302 goto err;
1303 }
1304
1305 slave_config.direction = DMA_DEV_TO_MEM;
1306 slave_config.src_addr = sport->port.mapbase + URXD0;
1307 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1308 /* one byte less than the watermark level to enable the aging timer */
1309 slave_config.src_maxburst = RXTL_DMA - 1;
1310 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1311 if (ret) {
1312 dev_err(dev, "error in RX dma configuration.\n");
1313 goto err;
1314 }
1315
1316 sport->rx_buf_size = sport->rx_period_length * sport->rx_periods;
1317 sport->rx_buf = kzalloc(sport->rx_buf_size, GFP_KERNEL);
1318 if (!sport->rx_buf) {
1319 ret = -ENOMEM;
1320 goto err;
1321 }
1322 sport->rx_ring.buf = sport->rx_buf;
1323
1324 /* Prepare for TX : */
1325 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1326 if (!sport->dma_chan_tx) {
1327 dev_err(dev, "cannot get the TX DMA channel!\n");
1328 ret = -EINVAL;
1329 goto err;
1330 }
1331
1332 slave_config.direction = DMA_MEM_TO_DEV;
1333 slave_config.dst_addr = sport->port.mapbase + URTX0;
1334 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1335 slave_config.dst_maxburst = TXTL_DMA;
1336 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1337 if (ret) {
1338 dev_err(dev, "error in TX dma configuration.");
1339 goto err;
1340 }
1341
1342 return 0;
1343err:
1344 imx_uart_dma_exit(sport);
1345 return ret;
1346}
1347
1348static void imx_uart_enable_dma(struct imx_port *sport)
1349{
1350 u32 ucr1;
1351
1352 imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1353
1354 /* set UCR1 */
1355 ucr1 = imx_uart_readl(sport, UCR1);
1356 ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
1357 imx_uart_writel(sport, ucr1, UCR1);
1358
1359 sport->dma_is_enabled = 1;
1360}
1361
1362static void imx_uart_disable_dma(struct imx_port *sport)
1363{
1364 u32 ucr1;
1365
1366 /* clear UCR1 */
1367 ucr1 = imx_uart_readl(sport, UCR1);
1368 ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
1369 imx_uart_writel(sport, ucr1, UCR1);
1370
1371 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1372
1373 sport->dma_is_enabled = 0;
1374}
1375
1376/* half the RX buffer size */
1377#define CTSTL 16
1378
1379static int imx_uart_startup(struct uart_port *port)
1380{
1381 struct imx_port *sport = (struct imx_port *)port;
1382 int retval, i;
1383 unsigned long flags;
1384 int dma_is_inited = 0;
1385 u32 ucr1, ucr2, ucr3, ucr4;
1386
1387 retval = clk_prepare_enable(sport->clk_per);
1388 if (retval)
1389 return retval;
1390 retval = clk_prepare_enable(sport->clk_ipg);
1391 if (retval) {
1392 clk_disable_unprepare(sport->clk_per);
1393 return retval;
1394 }
1395
1396 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1397
1398 /* disable the DREN bit (Data Ready interrupt enable) before
1399 * requesting IRQs
1400 */
1401 ucr4 = imx_uart_readl(sport, UCR4);
1402
1403 /* set the trigger level for CTS */
1404 ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1405 ucr4 |= CTSTL << UCR4_CTSTL_SHF;
1406
1407 imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
1408
1409 /* Can we enable the DMA support? */
1410 if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
1411 dma_is_inited = 1;
1412
1413 spin_lock_irqsave(&sport->port.lock, flags);
1414 /* Reset fifo's and state machines */
1415 i = 100;
1416
1417 ucr2 = imx_uart_readl(sport, UCR2);
1418 ucr2 &= ~UCR2_SRST;
1419 imx_uart_writel(sport, ucr2, UCR2);
1420
1421 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1422 udelay(1);
1423
1424 /*
1425 * Finally, clear and enable interrupts
1426 */
1427 imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
1428 imx_uart_writel(sport, USR2_ORE, USR2);
1429
1430 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
1431 ucr1 |= UCR1_UARTEN;
1432 if (sport->have_rtscts)
1433 ucr1 |= UCR1_RTSDEN;
1434
1435 imx_uart_writel(sport, ucr1, UCR1);
1436
1437 ucr4 = imx_uart_readl(sport, UCR4) & ~(UCR4_OREN | UCR4_INVR);
1438 if (!sport->dma_is_enabled)
1439 ucr4 |= UCR4_OREN;
1440 if (sport->inverted_rx)
1441 ucr4 |= UCR4_INVR;
1442 imx_uart_writel(sport, ucr4, UCR4);
1443
1444 ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_INVT;
1445 /*
1446 * configure tx polarity before enabling tx
1447 */
1448 if (sport->inverted_tx)
1449 ucr3 |= UCR3_INVT;
1450
1451 if (!imx_uart_is_imx1(sport)) {
1452 ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1453
1454 if (sport->dte_mode)
1455 /* disable broken interrupts */
1456 ucr3 &= ~(UCR3_RI | UCR3_DCD);
1457 }
1458 imx_uart_writel(sport, ucr3, UCR3);
1459
1460 ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
1461 ucr2 |= (UCR2_RXEN | UCR2_TXEN);
1462 if (!sport->have_rtscts)
1463 ucr2 |= UCR2_IRTS;
1464 /*
1465 * make sure the edge sensitive RTS-irq is disabled,
1466 * we're using RTSD instead.
1467 */
1468 if (!imx_uart_is_imx1(sport))
1469 ucr2 &= ~UCR2_RTSEN;
1470 imx_uart_writel(sport, ucr2, UCR2);
1471
1472 /*
1473 * Enable modem status interrupts
1474 */
1475 imx_uart_enable_ms(&sport->port);
1476
1477 if (dma_is_inited) {
1478 imx_uart_enable_dma(sport);
1479 imx_uart_start_rx_dma(sport);
1480 } else {
1481 ucr1 = imx_uart_readl(sport, UCR1);
1482 ucr1 |= UCR1_RRDYEN;
1483 imx_uart_writel(sport, ucr1, UCR1);
1484
1485 ucr2 = imx_uart_readl(sport, UCR2);
1486 ucr2 |= UCR2_ATEN;
1487 imx_uart_writel(sport, ucr2, UCR2);
1488 }
1489
1490 spin_unlock_irqrestore(&sport->port.lock, flags);
1491
1492 return 0;
1493}
1494
1495static void imx_uart_shutdown(struct uart_port *port)
1496{
1497 struct imx_port *sport = (struct imx_port *)port;
1498 unsigned long flags;
1499 u32 ucr1, ucr2, ucr4;
1500
1501 if (sport->dma_is_enabled) {
1502 dmaengine_terminate_sync(sport->dma_chan_tx);
1503 if (sport->dma_is_txing) {
1504 dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
1505 sport->dma_tx_nents, DMA_TO_DEVICE);
1506 sport->dma_is_txing = 0;
1507 }
1508 dmaengine_terminate_sync(sport->dma_chan_rx);
1509 if (sport->dma_is_rxing) {
1510 dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
1511 1, DMA_FROM_DEVICE);
1512 sport->dma_is_rxing = 0;
1513 }
1514
1515 spin_lock_irqsave(&sport->port.lock, flags);
1516 imx_uart_stop_tx(port);
1517 imx_uart_stop_rx(port);
1518 imx_uart_disable_dma(sport);
1519 spin_unlock_irqrestore(&sport->port.lock, flags);
1520 imx_uart_dma_exit(sport);
1521 }
1522
1523 mctrl_gpio_disable_ms(sport->gpios);
1524
1525 spin_lock_irqsave(&sport->port.lock, flags);
1526 ucr2 = imx_uart_readl(sport, UCR2);
1527 ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
1528 imx_uart_writel(sport, ucr2, UCR2);
1529 spin_unlock_irqrestore(&sport->port.lock, flags);
1530
1531 /*
1532 * Stop our timer.
1533 */
1534 del_timer_sync(&sport->timer);
1535
1536 /*
1537 * Disable all interrupts, port and break condition.
1538 */
1539
1540 spin_lock_irqsave(&sport->port.lock, flags);
1541
1542 ucr1 = imx_uart_readl(sport, UCR1);
1543 ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
1544 imx_uart_writel(sport, ucr1, UCR1);
1545
1546 ucr4 = imx_uart_readl(sport, UCR4);
1547 ucr4 &= ~(UCR4_OREN | UCR4_TCEN);
1548 imx_uart_writel(sport, ucr4, UCR4);
1549
1550 spin_unlock_irqrestore(&sport->port.lock, flags);
1551
1552 clk_disable_unprepare(sport->clk_per);
1553 clk_disable_unprepare(sport->clk_ipg);
1554}
1555
1556/* called with port.lock taken and irqs off */
1557static void imx_uart_flush_buffer(struct uart_port *port)
1558{
1559 struct imx_port *sport = (struct imx_port *)port;
1560 struct scatterlist *sgl = &sport->tx_sgl[0];
1561 u32 ucr2;
1562 int i = 100, ubir, ubmr, uts;
1563
1564 if (!sport->dma_chan_tx)
1565 return;
1566
1567 sport->tx_bytes = 0;
1568 dmaengine_terminate_all(sport->dma_chan_tx);
1569 if (sport->dma_is_txing) {
1570 u32 ucr1;
1571
1572 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1573 DMA_TO_DEVICE);
1574 ucr1 = imx_uart_readl(sport, UCR1);
1575 ucr1 &= ~UCR1_TXDMAEN;
1576 imx_uart_writel(sport, ucr1, UCR1);
1577 sport->dma_is_txing = 0;
1578 }
1579
1580 /*
1581 * According to the Reference Manual description of the UART SRST bit:
1582 *
1583 * "Reset the transmit and receive state machines,
1584 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1585 * and UTS[6-3]".
1586 *
1587 * We don't need to restore the old values from USR1, USR2, URXD and
1588 * UTXD. UBRC is read only, so only save/restore the other three
1589 * registers.
1590 */
1591 ubir = imx_uart_readl(sport, UBIR);
1592 ubmr = imx_uart_readl(sport, UBMR);
1593 uts = imx_uart_readl(sport, IMX21_UTS);
1594
1595 ucr2 = imx_uart_readl(sport, UCR2);
1596 ucr2 &= ~UCR2_SRST;
1597 imx_uart_writel(sport, ucr2, UCR2);
1598
1599 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1600 udelay(1);
1601
1602 /* Restore the registers */
1603 imx_uart_writel(sport, ubir, UBIR);
1604 imx_uart_writel(sport, ubmr, UBMR);
1605 imx_uart_writel(sport, uts, IMX21_UTS);
1606}
1607
1608static void
1609imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
1610 struct ktermios *old)
1611{
1612 struct imx_port *sport = (struct imx_port *)port;
1613 unsigned long flags;
1614 u32 ucr2, old_ucr2, ufcr;
1615 unsigned int baud, quot;
1616 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1617 unsigned long div;
1618 unsigned long num, denom, old_ubir, old_ubmr;
1619 uint64_t tdiv64;
1620
1621 /*
1622 * We only support CS7 and CS8.
1623 */
1624 while ((termios->c_cflag & CSIZE) != CS7 &&
1625 (termios->c_cflag & CSIZE) != CS8) {
1626 termios->c_cflag &= ~CSIZE;
1627 termios->c_cflag |= old_csize;
1628 old_csize = CS8;
1629 }
1630
1631 del_timer_sync(&sport->timer);
1632
1633 /*
1634 * Ask the core to calculate the divisor for us.
1635 */
1636 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1637 quot = uart_get_divisor(port, baud);
1638
1639 spin_lock_irqsave(&sport->port.lock, flags);
1640
1641 /*
1642 * Read current UCR2 and save it for future use, then clear all the bits
1643 * except those we will or may need to preserve.
1644 */
1645 old_ucr2 = imx_uart_readl(sport, UCR2);
1646 ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
1647
1648 ucr2 |= UCR2_SRST | UCR2_IRTS;
1649 if ((termios->c_cflag & CSIZE) == CS8)
1650 ucr2 |= UCR2_WS;
1651
1652 if (!sport->have_rtscts)
1653 termios->c_cflag &= ~CRTSCTS;
1654
1655 if (port->rs485.flags & SER_RS485_ENABLED) {
1656 /*
1657 * RTS is mandatory for rs485 operation, so keep
1658 * it under manual control and keep transmitter
1659 * disabled.
1660 */
1661 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1662 imx_uart_rts_active(sport, &ucr2);
1663 else
1664 imx_uart_rts_inactive(sport, &ucr2);
1665
1666 } else if (termios->c_cflag & CRTSCTS) {
1667 /*
1668 * Only let receiver control RTS output if we were not requested
1669 * to have RTS inactive (which then should take precedence).
1670 */
1671 if (ucr2 & UCR2_CTS)
1672 ucr2 |= UCR2_CTSC;
1673 }
1674
1675 if (termios->c_cflag & CRTSCTS)
1676 ucr2 &= ~UCR2_IRTS;
1677 if (termios->c_cflag & CSTOPB)
1678 ucr2 |= UCR2_STPB;
1679 if (termios->c_cflag & PARENB) {
1680 ucr2 |= UCR2_PREN;
1681 if (termios->c_cflag & PARODD)
1682 ucr2 |= UCR2_PROE;
1683 }
1684
1685 sport->port.read_status_mask = 0;
1686 if (termios->c_iflag & INPCK)
1687 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1688 if (termios->c_iflag & (BRKINT | PARMRK))
1689 sport->port.read_status_mask |= URXD_BRK;
1690
1691 /*
1692 * Characters to ignore
1693 */
1694 sport->port.ignore_status_mask = 0;
1695 if (termios->c_iflag & IGNPAR)
1696 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1697 if (termios->c_iflag & IGNBRK) {
1698 sport->port.ignore_status_mask |= URXD_BRK;
1699 /*
1700 * If we're ignoring parity and break indicators,
1701 * ignore overruns too (for real raw support).
1702 */
1703 if (termios->c_iflag & IGNPAR)
1704 sport->port.ignore_status_mask |= URXD_OVRRUN;
1705 }
1706
1707 if ((termios->c_cflag & CREAD) == 0)
1708 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1709
1710 /*
1711 * Update the per-port timeout.
1712 */
1713 uart_update_timeout(port, termios->c_cflag, baud);
1714
1715 /* custom-baudrate handling */
1716 div = sport->port.uartclk / (baud * 16);
1717 if (baud == 38400 && quot != div)
1718 baud = sport->port.uartclk / (quot * 16);
1719
1720 div = sport->port.uartclk / (baud * 16);
1721 if (div > 7)
1722 div = 7;
1723 if (!div)
1724 div = 1;
1725
1726 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1727 1 << 16, 1 << 16, &num, &denom);
1728
1729 tdiv64 = sport->port.uartclk;
1730 tdiv64 *= num;
1731 do_div(tdiv64, denom * 16 * div);
1732 tty_termios_encode_baud_rate(termios,
1733 (speed_t)tdiv64, (speed_t)tdiv64);
1734
1735 num -= 1;
1736 denom -= 1;
1737
1738 ufcr = imx_uart_readl(sport, UFCR);
1739 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1740 imx_uart_writel(sport, ufcr, UFCR);
1741
1742 /*
1743 * Two registers below should always be written both and in this
1744 * particular order. One consequence is that we need to check if any of
1745 * them changes and then update both. We do need the check for change
1746 * as even writing the same values seem to "restart"
1747 * transmission/receiving logic in the hardware, that leads to data
1748 * breakage even when rate doesn't in fact change. E.g., user switches
1749 * RTS/CTS handshake and suddenly gets broken bytes.
1750 */
1751 old_ubir = imx_uart_readl(sport, UBIR);
1752 old_ubmr = imx_uart_readl(sport, UBMR);
1753 if (old_ubir != num || old_ubmr != denom) {
1754 imx_uart_writel(sport, num, UBIR);
1755 imx_uart_writel(sport, denom, UBMR);
1756 }
1757
1758 if (!imx_uart_is_imx1(sport))
1759 imx_uart_writel(sport, sport->port.uartclk / div / 1000,
1760 IMX21_ONEMS);
1761
1762 imx_uart_writel(sport, ucr2, UCR2);
1763
1764 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1765 imx_uart_enable_ms(&sport->port);
1766
1767 spin_unlock_irqrestore(&sport->port.lock, flags);
1768}
1769
1770static const char *imx_uart_type(struct uart_port *port)
1771{
1772 struct imx_port *sport = (struct imx_port *)port;
1773
1774 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1775}
1776
1777/*
1778 * Configure/autoconfigure the port.
1779 */
1780static void imx_uart_config_port(struct uart_port *port, int flags)
1781{
1782 struct imx_port *sport = (struct imx_port *)port;
1783
1784 if (flags & UART_CONFIG_TYPE)
1785 sport->port.type = PORT_IMX;
1786}
1787
1788/*
1789 * Verify the new serial_struct (for TIOCSSERIAL).
1790 * The only change we allow are to the flags and type, and
1791 * even then only between PORT_IMX and PORT_UNKNOWN
1792 */
1793static int
1794imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
1795{
1796 struct imx_port *sport = (struct imx_port *)port;
1797 int ret = 0;
1798
1799 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1800 ret = -EINVAL;
1801 if (sport->port.irq != ser->irq)
1802 ret = -EINVAL;
1803 if (ser->io_type != UPIO_MEM)
1804 ret = -EINVAL;
1805 if (sport->port.uartclk / 16 != ser->baud_base)
1806 ret = -EINVAL;
1807 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1808 ret = -EINVAL;
1809 if (sport->port.iobase != ser->port)
1810 ret = -EINVAL;
1811 if (ser->hub6 != 0)
1812 ret = -EINVAL;
1813 return ret;
1814}
1815
1816#if defined(CONFIG_CONSOLE_POLL)
1817
1818static int imx_uart_poll_init(struct uart_port *port)
1819{
1820 struct imx_port *sport = (struct imx_port *)port;
1821 unsigned long flags;
1822 u32 ucr1, ucr2;
1823 int retval;
1824
1825 retval = clk_prepare_enable(sport->clk_ipg);
1826 if (retval)
1827 return retval;
1828 retval = clk_prepare_enable(sport->clk_per);
1829 if (retval)
1830 clk_disable_unprepare(sport->clk_ipg);
1831
1832 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1833
1834 spin_lock_irqsave(&sport->port.lock, flags);
1835
1836 /*
1837 * Be careful about the order of enabling bits here. First enable the
1838 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
1839 * This prevents that a character that already sits in the RX fifo is
1840 * triggering an irq but the try to fetch it from there results in an
1841 * exception because UARTEN or RXEN is still off.
1842 */
1843 ucr1 = imx_uart_readl(sport, UCR1);
1844 ucr2 = imx_uart_readl(sport, UCR2);
1845
1846 if (imx_uart_is_imx1(sport))
1847 ucr1 |= IMX1_UCR1_UARTCLKEN;
1848
1849 ucr1 |= UCR1_UARTEN;
1850 ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
1851
1852 ucr2 |= UCR2_RXEN | UCR2_TXEN;
1853 ucr2 &= ~UCR2_ATEN;
1854
1855 imx_uart_writel(sport, ucr1, UCR1);
1856 imx_uart_writel(sport, ucr2, UCR2);
1857
1858 /* now enable irqs */
1859 imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
1860 imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
1861
1862 spin_unlock_irqrestore(&sport->port.lock, flags);
1863
1864 return 0;
1865}
1866
1867static int imx_uart_poll_get_char(struct uart_port *port)
1868{
1869 struct imx_port *sport = (struct imx_port *)port;
1870 if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
1871 return NO_POLL_CHAR;
1872
1873 return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
1874}
1875
1876static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
1877{
1878 struct imx_port *sport = (struct imx_port *)port;
1879 unsigned int status;
1880
1881 /* drain */
1882 do {
1883 status = imx_uart_readl(sport, USR1);
1884 } while (~status & USR1_TRDY);
1885
1886 /* write */
1887 imx_uart_writel(sport, c, URTX0);
1888
1889 /* flush */
1890 do {
1891 status = imx_uart_readl(sport, USR2);
1892 } while (~status & USR2_TXDC);
1893}
1894#endif
1895
1896/* called with port.lock taken and irqs off or from .probe without locking */
1897static int imx_uart_rs485_config(struct uart_port *port,
1898 struct serial_rs485 *rs485conf)
1899{
1900 struct imx_port *sport = (struct imx_port *)port;
1901 u32 ucr2;
1902
1903 /* RTS is required to control the transmitter */
1904 if (!sport->have_rtscts && !sport->have_rtsgpio)
1905 rs485conf->flags &= ~SER_RS485_ENABLED;
1906
1907 if (rs485conf->flags & SER_RS485_ENABLED) {
1908 /* Enable receiver if low-active RTS signal is requested */
1909 if (sport->have_rtscts && !sport->have_rtsgpio &&
1910 !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
1911 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1912
1913 /* disable transmitter */
1914 ucr2 = imx_uart_readl(sport, UCR2);
1915 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1916 imx_uart_rts_active(sport, &ucr2);
1917 else
1918 imx_uart_rts_inactive(sport, &ucr2);
1919 imx_uart_writel(sport, ucr2, UCR2);
1920 }
1921
1922 /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1923 if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1924 rs485conf->flags & SER_RS485_RX_DURING_TX)
1925 imx_uart_start_rx(port);
1926
1927 port->rs485 = *rs485conf;
1928
1929 return 0;
1930}
1931
1932static const struct uart_ops imx_uart_pops = {
1933 .tx_empty = imx_uart_tx_empty,
1934 .set_mctrl = imx_uart_set_mctrl,
1935 .get_mctrl = imx_uart_get_mctrl,
1936 .stop_tx = imx_uart_stop_tx,
1937 .start_tx = imx_uart_start_tx,
1938 .stop_rx = imx_uart_stop_rx,
1939 .enable_ms = imx_uart_enable_ms,
1940 .break_ctl = imx_uart_break_ctl,
1941 .startup = imx_uart_startup,
1942 .shutdown = imx_uart_shutdown,
1943 .flush_buffer = imx_uart_flush_buffer,
1944 .set_termios = imx_uart_set_termios,
1945 .type = imx_uart_type,
1946 .config_port = imx_uart_config_port,
1947 .verify_port = imx_uart_verify_port,
1948#if defined(CONFIG_CONSOLE_POLL)
1949 .poll_init = imx_uart_poll_init,
1950 .poll_get_char = imx_uart_poll_get_char,
1951 .poll_put_char = imx_uart_poll_put_char,
1952#endif
1953};
1954
1955static struct imx_port *imx_uart_ports[UART_NR];
1956
1957#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
1958static void imx_uart_console_putchar(struct uart_port *port, int ch)
1959{
1960 struct imx_port *sport = (struct imx_port *)port;
1961
1962 while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
1963 barrier();
1964
1965 imx_uart_writel(sport, ch, URTX0);
1966}
1967
1968/*
1969 * Interrupts are disabled on entering
1970 */
1971static void
1972imx_uart_console_write(struct console *co, const char *s, unsigned int count)
1973{
1974 struct imx_port *sport = imx_uart_ports[co->index];
1975 struct imx_port_ucrs old_ucr;
1976 unsigned long flags;
1977 unsigned int ucr1;
1978 int locked = 1;
1979
1980 if (sport->port.sysrq)
1981 locked = 0;
1982 else if (oops_in_progress)
1983 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1984 else
1985 spin_lock_irqsave(&sport->port.lock, flags);
1986
1987 /*
1988 * First, save UCR1/2/3 and then disable interrupts
1989 */
1990 imx_uart_ucrs_save(sport, &old_ucr);
1991 ucr1 = old_ucr.ucr1;
1992
1993 if (imx_uart_is_imx1(sport))
1994 ucr1 |= IMX1_UCR1_UARTCLKEN;
1995 ucr1 |= UCR1_UARTEN;
1996 ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1997
1998 imx_uart_writel(sport, ucr1, UCR1);
1999
2000 imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
2001
2002 uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
2003
2004 /*
2005 * Finally, wait for transmitter to become empty
2006 * and restore UCR1/2/3
2007 */
2008 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
2009
2010 imx_uart_ucrs_restore(sport, &old_ucr);
2011
2012 if (locked)
2013 spin_unlock_irqrestore(&sport->port.lock, flags);
2014}
2015
2016/*
2017 * If the port was already initialised (eg, by a boot loader),
2018 * try to determine the current setup.
2019 */
2020static void __init
2021imx_uart_console_get_options(struct imx_port *sport, int *baud,
2022 int *parity, int *bits)
2023{
2024
2025 if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
2026 /* ok, the port was enabled */
2027 unsigned int ucr2, ubir, ubmr, uartclk;
2028 unsigned int baud_raw;
2029 unsigned int ucfr_rfdiv;
2030
2031 ucr2 = imx_uart_readl(sport, UCR2);
2032
2033 *parity = 'n';
2034 if (ucr2 & UCR2_PREN) {
2035 if (ucr2 & UCR2_PROE)
2036 *parity = 'o';
2037 else
2038 *parity = 'e';
2039 }
2040
2041 if (ucr2 & UCR2_WS)
2042 *bits = 8;
2043 else
2044 *bits = 7;
2045
2046 ubir = imx_uart_readl(sport, UBIR) & 0xffff;
2047 ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
2048
2049 ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
2050 if (ucfr_rfdiv == 6)
2051 ucfr_rfdiv = 7;
2052 else
2053 ucfr_rfdiv = 6 - ucfr_rfdiv;
2054
2055 uartclk = clk_get_rate(sport->clk_per);
2056 uartclk /= ucfr_rfdiv;
2057
2058 { /*
2059 * The next code provides exact computation of
2060 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
2061 * without need of float support or long long division,
2062 * which would be required to prevent 32bit arithmetic overflow
2063 */
2064 unsigned int mul = ubir + 1;
2065 unsigned int div = 16 * (ubmr + 1);
2066 unsigned int rem = uartclk % div;
2067
2068 baud_raw = (uartclk / div) * mul;
2069 baud_raw += (rem * mul + div / 2) / div;
2070 *baud = (baud_raw + 50) / 100 * 100;
2071 }
2072
2073 if (*baud != baud_raw)
2074 dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
2075 baud_raw, *baud);
2076 }
2077}
2078
2079static int __init
2080imx_uart_console_setup(struct console *co, char *options)
2081{
2082 struct imx_port *sport;
2083 int baud = 9600;
2084 int bits = 8;
2085 int parity = 'n';
2086 int flow = 'n';
2087 int retval;
2088
2089 /*
2090 * Check whether an invalid uart number has been specified, and
2091 * if so, search for the first available port that does have
2092 * console support.
2093 */
2094 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
2095 co->index = 0;
2096 sport = imx_uart_ports[co->index];
2097 if (sport == NULL)
2098 return -ENODEV;
2099
2100 /* For setting the registers, we only need to enable the ipg clock. */
2101 retval = clk_prepare_enable(sport->clk_ipg);
2102 if (retval)
2103 goto error_console;
2104
2105 if (options)
2106 uart_parse_options(options, &baud, &parity, &bits, &flow);
2107 else
2108 imx_uart_console_get_options(sport, &baud, &parity, &bits);
2109
2110 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
2111
2112 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
2113
2114 if (retval) {
2115 clk_disable_unprepare(sport->clk_ipg);
2116 goto error_console;
2117 }
2118
2119 retval = clk_prepare_enable(sport->clk_per);
2120 if (retval)
2121 clk_disable_unprepare(sport->clk_ipg);
2122
2123error_console:
2124 return retval;
2125}
2126
2127static struct uart_driver imx_uart_uart_driver;
2128static struct console imx_uart_console = {
2129 .name = DEV_NAME,
2130 .write = imx_uart_console_write,
2131 .device = uart_console_device,
2132 .setup = imx_uart_console_setup,
2133 .flags = CON_PRINTBUFFER,
2134 .index = -1,
2135 .data = &imx_uart_uart_driver,
2136};
2137
2138#define IMX_CONSOLE &imx_uart_console
2139
2140#else
2141#define IMX_CONSOLE NULL
2142#endif
2143
2144static struct uart_driver imx_uart_uart_driver = {
2145 .owner = THIS_MODULE,
2146 .driver_name = DRIVER_NAME,
2147 .dev_name = DEV_NAME,
2148 .major = SERIAL_IMX_MAJOR,
2149 .minor = MINOR_START,
2150 .nr = ARRAY_SIZE(imx_uart_ports),
2151 .cons = IMX_CONSOLE,
2152};
2153
2154static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t)
2155{
2156 struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx);
2157 unsigned long flags;
2158
2159 spin_lock_irqsave(&sport->port.lock, flags);
2160 if (sport->tx_state == WAIT_AFTER_RTS)
2161 imx_uart_start_tx(&sport->port);
2162 spin_unlock_irqrestore(&sport->port.lock, flags);
2163
2164 return HRTIMER_NORESTART;
2165}
2166
2167static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
2168{
2169 struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx);
2170 unsigned long flags;
2171
2172 spin_lock_irqsave(&sport->port.lock, flags);
2173 if (sport->tx_state == WAIT_AFTER_SEND)
2174 imx_uart_stop_tx(&sport->port);
2175 spin_unlock_irqrestore(&sport->port.lock, flags);
2176
2177 return HRTIMER_NORESTART;
2178}
2179
2180/* Default RX DMA buffer configuration */
2181#define RX_DMA_PERIODS 16
2182#define RX_DMA_PERIOD_LEN (PAGE_SIZE / 4)
2183
2184static int imx_uart_probe(struct platform_device *pdev)
2185{
2186 struct device_node *np = pdev->dev.of_node;
2187 struct imx_port *sport;
2188 void __iomem *base;
2189 u32 dma_buf_conf[2];
2190 int ret = 0;
2191 u32 ucr1;
2192 struct resource *res;
2193 int txirq, rxirq, rtsirq;
2194
2195 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2196 if (!sport)
2197 return -ENOMEM;
2198
2199 sport->devdata = of_device_get_match_data(&pdev->dev);
2200
2201 ret = of_alias_get_id(np, "serial");
2202 if (ret < 0) {
2203 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2204 return ret;
2205 }
2206 sport->port.line = ret;
2207
2208 if (of_get_property(np, "uart-has-rtscts", NULL) ||
2209 of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2210 sport->have_rtscts = 1;
2211
2212 if (of_get_property(np, "fsl,dte-mode", NULL))
2213 sport->dte_mode = 1;
2214
2215 if (of_get_property(np, "rts-gpios", NULL))
2216 sport->have_rtsgpio = 1;
2217
2218 if (of_get_property(np, "fsl,inverted-tx", NULL))
2219 sport->inverted_tx = 1;
2220
2221 if (of_get_property(np, "fsl,inverted-rx", NULL))
2222 sport->inverted_rx = 1;
2223
2224 if (!of_property_read_u32_array(np, "fsl,dma-info", dma_buf_conf, 2)) {
2225 sport->rx_period_length = dma_buf_conf[0];
2226 sport->rx_periods = dma_buf_conf[1];
2227 } else {
2228 sport->rx_period_length = RX_DMA_PERIOD_LEN;
2229 sport->rx_periods = RX_DMA_PERIODS;
2230 }
2231
2232 if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
2233 dev_err(&pdev->dev, "serial%d out of range\n",
2234 sport->port.line);
2235 return -EINVAL;
2236 }
2237
2238 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2239 base = devm_ioremap_resource(&pdev->dev, res);
2240 if (IS_ERR(base))
2241 return PTR_ERR(base);
2242
2243 rxirq = platform_get_irq(pdev, 0);
2244 if (rxirq < 0)
2245 return rxirq;
2246 txirq = platform_get_irq_optional(pdev, 1);
2247 rtsirq = platform_get_irq_optional(pdev, 2);
2248
2249 sport->port.dev = &pdev->dev;
2250 sport->port.mapbase = res->start;
2251 sport->port.membase = base;
2252 sport->port.type = PORT_IMX;
2253 sport->port.iotype = UPIO_MEM;
2254 sport->port.irq = rxirq;
2255 sport->port.fifosize = 32;
2256 sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE);
2257 sport->port.ops = &imx_uart_pops;
2258 sport->port.rs485_config = imx_uart_rs485_config;
2259 sport->port.flags = UPF_BOOT_AUTOCONF;
2260 timer_setup(&sport->timer, imx_uart_timeout, 0);
2261
2262 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2263 if (IS_ERR(sport->gpios))
2264 return PTR_ERR(sport->gpios);
2265
2266 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2267 if (IS_ERR(sport->clk_ipg)) {
2268 ret = PTR_ERR(sport->clk_ipg);
2269 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2270 return ret;
2271 }
2272
2273 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2274 if (IS_ERR(sport->clk_per)) {
2275 ret = PTR_ERR(sport->clk_per);
2276 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2277 return ret;
2278 }
2279
2280 sport->port.uartclk = clk_get_rate(sport->clk_per);
2281
2282 /* For register access, we only need to enable the ipg clock. */
2283 ret = clk_prepare_enable(sport->clk_ipg);
2284 if (ret) {
2285 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2286 return ret;
2287 }
2288
2289 /* initialize shadow register values */
2290 sport->ucr1 = readl(sport->port.membase + UCR1);
2291 sport->ucr2 = readl(sport->port.membase + UCR2);
2292 sport->ucr3 = readl(sport->port.membase + UCR3);
2293 sport->ucr4 = readl(sport->port.membase + UCR4);
2294 sport->ufcr = readl(sport->port.membase + UFCR);
2295
2296 ret = uart_get_rs485_mode(&sport->port);
2297 if (ret) {
2298 clk_disable_unprepare(sport->clk_ipg);
2299 return ret;
2300 }
2301
2302 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2303 (!sport->have_rtscts && !sport->have_rtsgpio))
2304 dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
2305
2306 /*
2307 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
2308 * signal cannot be set low during transmission in case the
2309 * receiver is off (limitation of the i.MX UART IP).
2310 */
2311 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2312 sport->have_rtscts && !sport->have_rtsgpio &&
2313 (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
2314 !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
2315 dev_err(&pdev->dev,
2316 "low-active RTS not possible when receiver is off, enabling receiver\n");
2317
2318 imx_uart_rs485_config(&sport->port, &sport->port.rs485);
2319
2320 /* Disable interrupts before requesting them */
2321 ucr1 = imx_uart_readl(sport, UCR1);
2322 ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN | UCR1_RTSDEN);
2323 imx_uart_writel(sport, ucr1, UCR1);
2324
2325 if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
2326 /*
2327 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2328 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2329 * and DCD (when they are outputs) or enables the respective
2330 * irqs. So set this bit early, i.e. before requesting irqs.
2331 */
2332 u32 ufcr = imx_uart_readl(sport, UFCR);
2333 if (!(ufcr & UFCR_DCEDTE))
2334 imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
2335
2336 /*
2337 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2338 * enabled later because they cannot be cleared
2339 * (confirmed on i.MX25) which makes them unusable.
2340 */
2341 imx_uart_writel(sport,
2342 IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2343 UCR3);
2344
2345 } else {
2346 u32 ucr3 = UCR3_DSR;
2347 u32 ufcr = imx_uart_readl(sport, UFCR);
2348 if (ufcr & UFCR_DCEDTE)
2349 imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
2350
2351 if (!imx_uart_is_imx1(sport))
2352 ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2353 imx_uart_writel(sport, ucr3, UCR3);
2354 }
2355
2356 clk_disable_unprepare(sport->clk_ipg);
2357
2358 hrtimer_init(&sport->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
2359 hrtimer_init(&sport->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
2360 sport->trigger_start_tx.function = imx_trigger_start_tx;
2361 sport->trigger_stop_tx.function = imx_trigger_stop_tx;
2362
2363 /*
2364 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2365 * chips only have one interrupt.
2366 */
2367 if (txirq > 0) {
2368 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
2369 dev_name(&pdev->dev), sport);
2370 if (ret) {
2371 dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2372 ret);
2373 return ret;
2374 }
2375
2376 ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
2377 dev_name(&pdev->dev), sport);
2378 if (ret) {
2379 dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2380 ret);
2381 return ret;
2382 }
2383
2384 ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
2385 dev_name(&pdev->dev), sport);
2386 if (ret) {
2387 dev_err(&pdev->dev, "failed to request rts irq: %d\n",
2388 ret);
2389 return ret;
2390 }
2391 } else {
2392 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
2393 dev_name(&pdev->dev), sport);
2394 if (ret) {
2395 dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2396 return ret;
2397 }
2398 }
2399
2400 imx_uart_ports[sport->port.line] = sport;
2401
2402 platform_set_drvdata(pdev, sport);
2403
2404 return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
2405}
2406
2407static int imx_uart_remove(struct platform_device *pdev)
2408{
2409 struct imx_port *sport = platform_get_drvdata(pdev);
2410
2411 return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
2412}
2413
2414static void imx_uart_restore_context(struct imx_port *sport)
2415{
2416 unsigned long flags;
2417
2418 spin_lock_irqsave(&sport->port.lock, flags);
2419 if (!sport->context_saved) {
2420 spin_unlock_irqrestore(&sport->port.lock, flags);
2421 return;
2422 }
2423
2424 imx_uart_writel(sport, sport->saved_reg[4], UFCR);
2425 imx_uart_writel(sport, sport->saved_reg[5], UESC);
2426 imx_uart_writel(sport, sport->saved_reg[6], UTIM);
2427 imx_uart_writel(sport, sport->saved_reg[7], UBIR);
2428 imx_uart_writel(sport, sport->saved_reg[8], UBMR);
2429 imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
2430 imx_uart_writel(sport, sport->saved_reg[0], UCR1);
2431 imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
2432 imx_uart_writel(sport, sport->saved_reg[2], UCR3);
2433 imx_uart_writel(sport, sport->saved_reg[3], UCR4);
2434 sport->context_saved = false;
2435 spin_unlock_irqrestore(&sport->port.lock, flags);
2436}
2437
2438static void imx_uart_save_context(struct imx_port *sport)
2439{
2440 unsigned long flags;
2441
2442 /* Save necessary regs */
2443 spin_lock_irqsave(&sport->port.lock, flags);
2444 sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
2445 sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
2446 sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
2447 sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
2448 sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
2449 sport->saved_reg[5] = imx_uart_readl(sport, UESC);
2450 sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
2451 sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
2452 sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
2453 sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
2454 sport->context_saved = true;
2455 spin_unlock_irqrestore(&sport->port.lock, flags);
2456}
2457
2458static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
2459{
2460 u32 ucr3;
2461
2462 ucr3 = imx_uart_readl(sport, UCR3);
2463 if (on) {
2464 imx_uart_writel(sport, USR1_AWAKE, USR1);
2465 ucr3 |= UCR3_AWAKEN;
2466 } else {
2467 ucr3 &= ~UCR3_AWAKEN;
2468 }
2469 imx_uart_writel(sport, ucr3, UCR3);
2470
2471 if (sport->have_rtscts) {
2472 u32 ucr1 = imx_uart_readl(sport, UCR1);
2473 if (on)
2474 ucr1 |= UCR1_RTSDEN;
2475 else
2476 ucr1 &= ~UCR1_RTSDEN;
2477 imx_uart_writel(sport, ucr1, UCR1);
2478 }
2479}
2480
2481static int imx_uart_suspend_noirq(struct device *dev)
2482{
2483 struct imx_port *sport = dev_get_drvdata(dev);
2484
2485 imx_uart_save_context(sport);
2486
2487 clk_disable(sport->clk_ipg);
2488
2489 pinctrl_pm_select_sleep_state(dev);
2490
2491 return 0;
2492}
2493
2494static int imx_uart_resume_noirq(struct device *dev)
2495{
2496 struct imx_port *sport = dev_get_drvdata(dev);
2497 int ret;
2498
2499 pinctrl_pm_select_default_state(dev);
2500
2501 ret = clk_enable(sport->clk_ipg);
2502 if (ret)
2503 return ret;
2504
2505 imx_uart_restore_context(sport);
2506
2507 return 0;
2508}
2509
2510static int imx_uart_suspend(struct device *dev)
2511{
2512 struct imx_port *sport = dev_get_drvdata(dev);
2513 int ret;
2514
2515 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2516 disable_irq(sport->port.irq);
2517
2518 ret = clk_prepare_enable(sport->clk_ipg);
2519 if (ret)
2520 return ret;
2521
2522 /* enable wakeup from i.MX UART */
2523 imx_uart_enable_wakeup(sport, true);
2524
2525 return 0;
2526}
2527
2528static int imx_uart_resume(struct device *dev)
2529{
2530 struct imx_port *sport = dev_get_drvdata(dev);
2531
2532 /* disable wakeup from i.MX UART */
2533 imx_uart_enable_wakeup(sport, false);
2534
2535 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2536 enable_irq(sport->port.irq);
2537
2538 clk_disable_unprepare(sport->clk_ipg);
2539
2540 return 0;
2541}
2542
2543static int imx_uart_freeze(struct device *dev)
2544{
2545 struct imx_port *sport = dev_get_drvdata(dev);
2546
2547 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2548
2549 return clk_prepare_enable(sport->clk_ipg);
2550}
2551
2552static int imx_uart_thaw(struct device *dev)
2553{
2554 struct imx_port *sport = dev_get_drvdata(dev);
2555
2556 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2557
2558 clk_disable_unprepare(sport->clk_ipg);
2559
2560 return 0;
2561}
2562
2563static const struct dev_pm_ops imx_uart_pm_ops = {
2564 .suspend_noirq = imx_uart_suspend_noirq,
2565 .resume_noirq = imx_uart_resume_noirq,
2566 .freeze_noirq = imx_uart_suspend_noirq,
2567 .restore_noirq = imx_uart_resume_noirq,
2568 .suspend = imx_uart_suspend,
2569 .resume = imx_uart_resume,
2570 .freeze = imx_uart_freeze,
2571 .thaw = imx_uart_thaw,
2572 .restore = imx_uart_thaw,
2573};
2574
2575static struct platform_driver imx_uart_platform_driver = {
2576 .probe = imx_uart_probe,
2577 .remove = imx_uart_remove,
2578
2579 .driver = {
2580 .name = "imx-uart",
2581 .of_match_table = imx_uart_dt_ids,
2582 .pm = &imx_uart_pm_ops,
2583 },
2584};
2585
2586static int __init imx_uart_init(void)
2587{
2588 int ret = uart_register_driver(&imx_uart_uart_driver);
2589
2590 if (ret)
2591 return ret;
2592
2593 ret = platform_driver_register(&imx_uart_platform_driver);
2594 if (ret != 0)
2595 uart_unregister_driver(&imx_uart_uart_driver);
2596
2597 return ret;
2598}
2599
2600static void __exit imx_uart_exit(void)
2601{
2602 platform_driver_unregister(&imx_uart_platform_driver);
2603 uart_unregister_driver(&imx_uart_uart_driver);
2604}
2605
2606module_init(imx_uart_init);
2607module_exit(imx_uart_exit);
2608
2609MODULE_AUTHOR("Sascha Hauer");
2610MODULE_DESCRIPTION("IMX generic serial port driver");
2611MODULE_LICENSE("GPL");
2612MODULE_ALIAS("platform:imx-uart");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for Motorola/Freescale IMX serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Author: Sascha Hauer <sascha@saschahauer.de>
8 * Copyright (C) 2004 Pengutronix
9 */
10
11#include <linux/module.h>
12#include <linux/ioport.h>
13#include <linux/init.h>
14#include <linux/console.h>
15#include <linux/sysrq.h>
16#include <linux/platform_device.h>
17#include <linux/tty.h>
18#include <linux/tty_flip.h>
19#include <linux/serial_core.h>
20#include <linux/serial.h>
21#include <linux/clk.h>
22#include <linux/delay.h>
23#include <linux/ktime.h>
24#include <linux/pinctrl/consumer.h>
25#include <linux/rational.h>
26#include <linux/slab.h>
27#include <linux/of.h>
28#include <linux/of_device.h>
29#include <linux/io.h>
30#include <linux/dma-mapping.h>
31
32#include <asm/irq.h>
33#include <linux/platform_data/serial-imx.h>
34#include <linux/platform_data/dma-imx.h>
35
36#include "serial_mctrl_gpio.h"
37
38/* Register definitions */
39#define URXD0 0x0 /* Receiver Register */
40#define URTX0 0x40 /* Transmitter Register */
41#define UCR1 0x80 /* Control Register 1 */
42#define UCR2 0x84 /* Control Register 2 */
43#define UCR3 0x88 /* Control Register 3 */
44#define UCR4 0x8c /* Control Register 4 */
45#define UFCR 0x90 /* FIFO Control Register */
46#define USR1 0x94 /* Status Register 1 */
47#define USR2 0x98 /* Status Register 2 */
48#define UESC 0x9c /* Escape Character Register */
49#define UTIM 0xa0 /* Escape Timer Register */
50#define UBIR 0xa4 /* BRM Incremental Register */
51#define UBMR 0xa8 /* BRM Modulator Register */
52#define UBRC 0xac /* Baud Rate Count Register */
53#define IMX21_ONEMS 0xb0 /* One Millisecond register */
54#define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
55#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
56
57/* UART Control Register Bit Fields.*/
58#define URXD_DUMMY_READ (1<<16)
59#define URXD_CHARRDY (1<<15)
60#define URXD_ERR (1<<14)
61#define URXD_OVRRUN (1<<13)
62#define URXD_FRMERR (1<<12)
63#define URXD_BRK (1<<11)
64#define URXD_PRERR (1<<10)
65#define URXD_RX_DATA (0xFF<<0)
66#define UCR1_ADEN (1<<15) /* Auto detect interrupt */
67#define UCR1_ADBR (1<<14) /* Auto detect baud rate */
68#define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
69#define UCR1_IDEN (1<<12) /* Idle condition interrupt */
70#define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
71#define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
72#define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */
73#define UCR1_IREN (1<<7) /* Infrared interface enable */
74#define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
75#define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
76#define UCR1_SNDBRK (1<<4) /* Send break */
77#define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */
78#define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
79#define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
80#define UCR1_DOZE (1<<1) /* Doze */
81#define UCR1_UARTEN (1<<0) /* UART enabled */
82#define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
83#define UCR2_IRTS (1<<14) /* Ignore RTS pin */
84#define UCR2_CTSC (1<<13) /* CTS pin control */
85#define UCR2_CTS (1<<12) /* Clear to send */
86#define UCR2_ESCEN (1<<11) /* Escape enable */
87#define UCR2_PREN (1<<8) /* Parity enable */
88#define UCR2_PROE (1<<7) /* Parity odd/even */
89#define UCR2_STPB (1<<6) /* Stop */
90#define UCR2_WS (1<<5) /* Word size */
91#define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
92#define UCR2_ATEN (1<<3) /* Aging Timer Enable */
93#define UCR2_TXEN (1<<2) /* Transmitter enabled */
94#define UCR2_RXEN (1<<1) /* Receiver enabled */
95#define UCR2_SRST (1<<0) /* SW reset */
96#define UCR3_DTREN (1<<13) /* DTR interrupt enable */
97#define UCR3_PARERREN (1<<12) /* Parity enable */
98#define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
99#define UCR3_DSR (1<<10) /* Data set ready */
100#define UCR3_DCD (1<<9) /* Data carrier detect */
101#define UCR3_RI (1<<8) /* Ring indicator */
102#define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
103#define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
104#define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
105#define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
106#define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
107#define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
108#define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
109#define UCR3_BPEN (1<<0) /* Preset registers enable */
110#define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
111#define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
112#define UCR4_INVR (1<<9) /* Inverted infrared reception */
113#define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
114#define UCR4_WKEN (1<<7) /* Wake interrupt enable */
115#define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
116#define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
117#define UCR4_IRSC (1<<5) /* IR special case */
118#define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
119#define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
120#define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
121#define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
122#define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
123#define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
124#define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
125#define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
126#define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
127#define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
128#define USR1_RTSS (1<<14) /* RTS pin status */
129#define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
130#define USR1_RTSD (1<<12) /* RTS delta */
131#define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
132#define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
133#define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
134#define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
135#define USR1_DTRD (1<<7) /* DTR Delta */
136#define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
137#define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
138#define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
139#define USR2_ADET (1<<15) /* Auto baud rate detect complete */
140#define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
141#define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
142#define USR2_IDLE (1<<12) /* Idle condition */
143#define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
144#define USR2_RIIN (1<<9) /* Ring Indicator Input */
145#define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
146#define USR2_WAKE (1<<7) /* Wake */
147#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
148#define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
149#define USR2_TXDC (1<<3) /* Transmitter complete */
150#define USR2_BRCD (1<<2) /* Break condition */
151#define USR2_ORE (1<<1) /* Overrun error */
152#define USR2_RDR (1<<0) /* Recv data ready */
153#define UTS_FRCPERR (1<<13) /* Force parity error */
154#define UTS_LOOP (1<<12) /* Loop tx and rx */
155#define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
156#define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
157#define UTS_TXFULL (1<<4) /* TxFIFO full */
158#define UTS_RXFULL (1<<3) /* RxFIFO full */
159#define UTS_SOFTRST (1<<0) /* Software reset */
160
161/* We've been assigned a range on the "Low-density serial ports" major */
162#define SERIAL_IMX_MAJOR 207
163#define MINOR_START 16
164#define DEV_NAME "ttymxc"
165
166/*
167 * This determines how often we check the modem status signals
168 * for any change. They generally aren't connected to an IRQ
169 * so we have to poll them. We also check immediately before
170 * filling the TX fifo incase CTS has been dropped.
171 */
172#define MCTRL_TIMEOUT (250*HZ/1000)
173
174#define DRIVER_NAME "IMX-uart"
175
176#define UART_NR 8
177
178/* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
179enum imx_uart_type {
180 IMX1_UART,
181 IMX21_UART,
182 IMX53_UART,
183 IMX6Q_UART,
184};
185
186/* device type dependent stuff */
187struct imx_uart_data {
188 unsigned uts_reg;
189 enum imx_uart_type devtype;
190};
191
192enum imx_tx_state {
193 OFF,
194 WAIT_AFTER_RTS,
195 SEND,
196 WAIT_AFTER_SEND,
197};
198
199struct imx_port {
200 struct uart_port port;
201 struct timer_list timer;
202 unsigned int old_status;
203 unsigned int have_rtscts:1;
204 unsigned int have_rtsgpio:1;
205 unsigned int dte_mode:1;
206 unsigned int inverted_tx:1;
207 unsigned int inverted_rx:1;
208 struct clk *clk_ipg;
209 struct clk *clk_per;
210 const struct imx_uart_data *devdata;
211
212 struct mctrl_gpios *gpios;
213
214 /* shadow registers */
215 unsigned int ucr1;
216 unsigned int ucr2;
217 unsigned int ucr3;
218 unsigned int ucr4;
219 unsigned int ufcr;
220
221 /* DMA fields */
222 unsigned int dma_is_enabled:1;
223 unsigned int dma_is_rxing:1;
224 unsigned int dma_is_txing:1;
225 struct dma_chan *dma_chan_rx, *dma_chan_tx;
226 struct scatterlist rx_sgl, tx_sgl[2];
227 void *rx_buf;
228 struct circ_buf rx_ring;
229 unsigned int rx_periods;
230 dma_cookie_t rx_cookie;
231 unsigned int tx_bytes;
232 unsigned int dma_tx_nents;
233 unsigned int saved_reg[10];
234 bool context_saved;
235
236 enum imx_tx_state tx_state;
237 struct hrtimer trigger_start_tx;
238 struct hrtimer trigger_stop_tx;
239};
240
241struct imx_port_ucrs {
242 unsigned int ucr1;
243 unsigned int ucr2;
244 unsigned int ucr3;
245};
246
247static struct imx_uart_data imx_uart_devdata[] = {
248 [IMX1_UART] = {
249 .uts_reg = IMX1_UTS,
250 .devtype = IMX1_UART,
251 },
252 [IMX21_UART] = {
253 .uts_reg = IMX21_UTS,
254 .devtype = IMX21_UART,
255 },
256 [IMX53_UART] = {
257 .uts_reg = IMX21_UTS,
258 .devtype = IMX53_UART,
259 },
260 [IMX6Q_UART] = {
261 .uts_reg = IMX21_UTS,
262 .devtype = IMX6Q_UART,
263 },
264};
265
266static const struct platform_device_id imx_uart_devtype[] = {
267 {
268 .name = "imx1-uart",
269 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
270 }, {
271 .name = "imx21-uart",
272 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
273 }, {
274 .name = "imx53-uart",
275 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
276 }, {
277 .name = "imx6q-uart",
278 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
279 }, {
280 /* sentinel */
281 }
282};
283MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
284
285static const struct of_device_id imx_uart_dt_ids[] = {
286 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
287 { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
288 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
289 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
290 { /* sentinel */ }
291};
292MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
293
294static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
295{
296 switch (offset) {
297 case UCR1:
298 sport->ucr1 = val;
299 break;
300 case UCR2:
301 sport->ucr2 = val;
302 break;
303 case UCR3:
304 sport->ucr3 = val;
305 break;
306 case UCR4:
307 sport->ucr4 = val;
308 break;
309 case UFCR:
310 sport->ufcr = val;
311 break;
312 default:
313 break;
314 }
315 writel(val, sport->port.membase + offset);
316}
317
318static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
319{
320 switch (offset) {
321 case UCR1:
322 return sport->ucr1;
323 break;
324 case UCR2:
325 /*
326 * UCR2_SRST is the only bit in the cached registers that might
327 * differ from the value that was last written. As it only
328 * automatically becomes one after being cleared, reread
329 * conditionally.
330 */
331 if (!(sport->ucr2 & UCR2_SRST))
332 sport->ucr2 = readl(sport->port.membase + offset);
333 return sport->ucr2;
334 break;
335 case UCR3:
336 return sport->ucr3;
337 break;
338 case UCR4:
339 return sport->ucr4;
340 break;
341 case UFCR:
342 return sport->ufcr;
343 break;
344 default:
345 return readl(sport->port.membase + offset);
346 }
347}
348
349static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
350{
351 return sport->devdata->uts_reg;
352}
353
354static inline int imx_uart_is_imx1(struct imx_port *sport)
355{
356 return sport->devdata->devtype == IMX1_UART;
357}
358
359static inline int imx_uart_is_imx21(struct imx_port *sport)
360{
361 return sport->devdata->devtype == IMX21_UART;
362}
363
364static inline int imx_uart_is_imx53(struct imx_port *sport)
365{
366 return sport->devdata->devtype == IMX53_UART;
367}
368
369static inline int imx_uart_is_imx6q(struct imx_port *sport)
370{
371 return sport->devdata->devtype == IMX6Q_UART;
372}
373/*
374 * Save and restore functions for UCR1, UCR2 and UCR3 registers
375 */
376#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
377static void imx_uart_ucrs_save(struct imx_port *sport,
378 struct imx_port_ucrs *ucr)
379{
380 /* save control registers */
381 ucr->ucr1 = imx_uart_readl(sport, UCR1);
382 ucr->ucr2 = imx_uart_readl(sport, UCR2);
383 ucr->ucr3 = imx_uart_readl(sport, UCR3);
384}
385
386static void imx_uart_ucrs_restore(struct imx_port *sport,
387 struct imx_port_ucrs *ucr)
388{
389 /* restore control registers */
390 imx_uart_writel(sport, ucr->ucr1, UCR1);
391 imx_uart_writel(sport, ucr->ucr2, UCR2);
392 imx_uart_writel(sport, ucr->ucr3, UCR3);
393}
394#endif
395
396/* called with port.lock taken and irqs caller dependent */
397static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
398{
399 *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
400
401 sport->port.mctrl |= TIOCM_RTS;
402 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
403}
404
405/* called with port.lock taken and irqs caller dependent */
406static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
407{
408 *ucr2 &= ~UCR2_CTSC;
409 *ucr2 |= UCR2_CTS;
410
411 sport->port.mctrl &= ~TIOCM_RTS;
412 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
413}
414
415static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
416{
417 long sec = msec / MSEC_PER_SEC;
418 long nsec = (msec % MSEC_PER_SEC) * 1000000;
419 ktime_t t = ktime_set(sec, nsec);
420
421 hrtimer_start(hrt, t, HRTIMER_MODE_REL);
422}
423
424/* called with port.lock taken and irqs off */
425static void imx_uart_start_rx(struct uart_port *port)
426{
427 struct imx_port *sport = (struct imx_port *)port;
428 unsigned int ucr1, ucr2;
429
430 ucr1 = imx_uart_readl(sport, UCR1);
431 ucr2 = imx_uart_readl(sport, UCR2);
432
433 ucr2 |= UCR2_RXEN;
434
435 if (sport->dma_is_enabled) {
436 ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
437 } else {
438 ucr1 |= UCR1_RRDYEN;
439 ucr2 |= UCR2_ATEN;
440 }
441
442 /* Write UCR2 first as it includes RXEN */
443 imx_uart_writel(sport, ucr2, UCR2);
444 imx_uart_writel(sport, ucr1, UCR1);
445}
446
447/* called with port.lock taken and irqs off */
448static void imx_uart_stop_tx(struct uart_port *port)
449{
450 struct imx_port *sport = (struct imx_port *)port;
451 u32 ucr1, ucr4, usr2;
452
453 if (sport->tx_state == OFF)
454 return;
455
456 /*
457 * We are maybe in the SMP context, so if the DMA TX thread is running
458 * on other cpu, we have to wait for it to finish.
459 */
460 if (sport->dma_is_txing)
461 return;
462
463 ucr1 = imx_uart_readl(sport, UCR1);
464 imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
465
466 usr2 = imx_uart_readl(sport, USR2);
467 if (!(usr2 & USR2_TXDC)) {
468 /* The shifter is still busy, so retry once TC triggers */
469 return;
470 }
471
472 ucr4 = imx_uart_readl(sport, UCR4);
473 ucr4 &= ~UCR4_TCEN;
474 imx_uart_writel(sport, ucr4, UCR4);
475
476 /* in rs485 mode disable transmitter */
477 if (port->rs485.flags & SER_RS485_ENABLED) {
478 if (sport->tx_state == SEND) {
479 sport->tx_state = WAIT_AFTER_SEND;
480 start_hrtimer_ms(&sport->trigger_stop_tx,
481 port->rs485.delay_rts_after_send);
482 return;
483 }
484
485 if (sport->tx_state == WAIT_AFTER_RTS ||
486 sport->tx_state == WAIT_AFTER_SEND) {
487 u32 ucr2;
488
489 hrtimer_try_to_cancel(&sport->trigger_start_tx);
490
491 ucr2 = imx_uart_readl(sport, UCR2);
492 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
493 imx_uart_rts_active(sport, &ucr2);
494 else
495 imx_uart_rts_inactive(sport, &ucr2);
496 imx_uart_writel(sport, ucr2, UCR2);
497
498 imx_uart_start_rx(port);
499
500 sport->tx_state = OFF;
501 }
502 } else {
503 sport->tx_state = OFF;
504 }
505}
506
507/* called with port.lock taken and irqs off */
508static void imx_uart_stop_rx(struct uart_port *port)
509{
510 struct imx_port *sport = (struct imx_port *)port;
511 u32 ucr1, ucr2;
512
513 ucr1 = imx_uart_readl(sport, UCR1);
514 ucr2 = imx_uart_readl(sport, UCR2);
515
516 if (sport->dma_is_enabled) {
517 ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
518 } else {
519 ucr1 &= ~UCR1_RRDYEN;
520 ucr2 &= ~UCR2_ATEN;
521 }
522 imx_uart_writel(sport, ucr1, UCR1);
523
524 ucr2 &= ~UCR2_RXEN;
525 imx_uart_writel(sport, ucr2, UCR2);
526}
527
528/* called with port.lock taken and irqs off */
529static void imx_uart_enable_ms(struct uart_port *port)
530{
531 struct imx_port *sport = (struct imx_port *)port;
532
533 mod_timer(&sport->timer, jiffies);
534
535 mctrl_gpio_enable_ms(sport->gpios);
536}
537
538static void imx_uart_dma_tx(struct imx_port *sport);
539
540/* called with port.lock taken and irqs off */
541static inline void imx_uart_transmit_buffer(struct imx_port *sport)
542{
543 struct circ_buf *xmit = &sport->port.state->xmit;
544
545 if (sport->port.x_char) {
546 /* Send next char */
547 imx_uart_writel(sport, sport->port.x_char, URTX0);
548 sport->port.icount.tx++;
549 sport->port.x_char = 0;
550 return;
551 }
552
553 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
554 imx_uart_stop_tx(&sport->port);
555 return;
556 }
557
558 if (sport->dma_is_enabled) {
559 u32 ucr1;
560 /*
561 * We've just sent a X-char Ensure the TX DMA is enabled
562 * and the TX IRQ is disabled.
563 **/
564 ucr1 = imx_uart_readl(sport, UCR1);
565 ucr1 &= ~UCR1_TRDYEN;
566 if (sport->dma_is_txing) {
567 ucr1 |= UCR1_TXDMAEN;
568 imx_uart_writel(sport, ucr1, UCR1);
569 } else {
570 imx_uart_writel(sport, ucr1, UCR1);
571 imx_uart_dma_tx(sport);
572 }
573
574 return;
575 }
576
577 while (!uart_circ_empty(xmit) &&
578 !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
579 /* send xmit->buf[xmit->tail]
580 * out the port here */
581 imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
582 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
583 sport->port.icount.tx++;
584 }
585
586 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
587 uart_write_wakeup(&sport->port);
588
589 if (uart_circ_empty(xmit))
590 imx_uart_stop_tx(&sport->port);
591}
592
593static void imx_uart_dma_tx_callback(void *data)
594{
595 struct imx_port *sport = data;
596 struct scatterlist *sgl = &sport->tx_sgl[0];
597 struct circ_buf *xmit = &sport->port.state->xmit;
598 unsigned long flags;
599 u32 ucr1;
600
601 spin_lock_irqsave(&sport->port.lock, flags);
602
603 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
604
605 ucr1 = imx_uart_readl(sport, UCR1);
606 ucr1 &= ~UCR1_TXDMAEN;
607 imx_uart_writel(sport, ucr1, UCR1);
608
609 /* update the stat */
610 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
611 sport->port.icount.tx += sport->tx_bytes;
612
613 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
614
615 sport->dma_is_txing = 0;
616
617 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
618 uart_write_wakeup(&sport->port);
619
620 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
621 imx_uart_dma_tx(sport);
622 else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
623 u32 ucr4 = imx_uart_readl(sport, UCR4);
624 ucr4 |= UCR4_TCEN;
625 imx_uart_writel(sport, ucr4, UCR4);
626 }
627
628 spin_unlock_irqrestore(&sport->port.lock, flags);
629}
630
631/* called with port.lock taken and irqs off */
632static void imx_uart_dma_tx(struct imx_port *sport)
633{
634 struct circ_buf *xmit = &sport->port.state->xmit;
635 struct scatterlist *sgl = sport->tx_sgl;
636 struct dma_async_tx_descriptor *desc;
637 struct dma_chan *chan = sport->dma_chan_tx;
638 struct device *dev = sport->port.dev;
639 u32 ucr1, ucr4;
640 int ret;
641
642 if (sport->dma_is_txing)
643 return;
644
645 ucr4 = imx_uart_readl(sport, UCR4);
646 ucr4 &= ~UCR4_TCEN;
647 imx_uart_writel(sport, ucr4, UCR4);
648
649 sport->tx_bytes = uart_circ_chars_pending(xmit);
650
651 if (xmit->tail < xmit->head || xmit->head == 0) {
652 sport->dma_tx_nents = 1;
653 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
654 } else {
655 sport->dma_tx_nents = 2;
656 sg_init_table(sgl, 2);
657 sg_set_buf(sgl, xmit->buf + xmit->tail,
658 UART_XMIT_SIZE - xmit->tail);
659 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
660 }
661
662 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
663 if (ret == 0) {
664 dev_err(dev, "DMA mapping error for TX.\n");
665 return;
666 }
667 desc = dmaengine_prep_slave_sg(chan, sgl, ret,
668 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
669 if (!desc) {
670 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
671 DMA_TO_DEVICE);
672 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
673 return;
674 }
675 desc->callback = imx_uart_dma_tx_callback;
676 desc->callback_param = sport;
677
678 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
679 uart_circ_chars_pending(xmit));
680
681 ucr1 = imx_uart_readl(sport, UCR1);
682 ucr1 |= UCR1_TXDMAEN;
683 imx_uart_writel(sport, ucr1, UCR1);
684
685 /* fire it */
686 sport->dma_is_txing = 1;
687 dmaengine_submit(desc);
688 dma_async_issue_pending(chan);
689 return;
690}
691
692/* called with port.lock taken and irqs off */
693static void imx_uart_start_tx(struct uart_port *port)
694{
695 struct imx_port *sport = (struct imx_port *)port;
696 u32 ucr1;
697
698 if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
699 return;
700
701 /*
702 * We cannot simply do nothing here if sport->tx_state == SEND already
703 * because UCR1_TXMPTYEN might already have been cleared in
704 * imx_uart_stop_tx(), but tx_state is still SEND.
705 */
706
707 if (port->rs485.flags & SER_RS485_ENABLED) {
708 if (sport->tx_state == OFF) {
709 u32 ucr2 = imx_uart_readl(sport, UCR2);
710 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
711 imx_uart_rts_active(sport, &ucr2);
712 else
713 imx_uart_rts_inactive(sport, &ucr2);
714 imx_uart_writel(sport, ucr2, UCR2);
715
716 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
717 imx_uart_stop_rx(port);
718
719 sport->tx_state = WAIT_AFTER_RTS;
720 start_hrtimer_ms(&sport->trigger_start_tx,
721 port->rs485.delay_rts_before_send);
722 return;
723 }
724
725 if (sport->tx_state == WAIT_AFTER_SEND
726 || sport->tx_state == WAIT_AFTER_RTS) {
727
728 hrtimer_try_to_cancel(&sport->trigger_stop_tx);
729
730 /*
731 * Enable transmitter and shifter empty irq only if DMA
732 * is off. In the DMA case this is done in the
733 * tx-callback.
734 */
735 if (!sport->dma_is_enabled) {
736 u32 ucr4 = imx_uart_readl(sport, UCR4);
737 ucr4 |= UCR4_TCEN;
738 imx_uart_writel(sport, ucr4, UCR4);
739 }
740
741 sport->tx_state = SEND;
742 }
743 } else {
744 sport->tx_state = SEND;
745 }
746
747 if (!sport->dma_is_enabled) {
748 ucr1 = imx_uart_readl(sport, UCR1);
749 imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1);
750 }
751
752 if (sport->dma_is_enabled) {
753 if (sport->port.x_char) {
754 /* We have X-char to send, so enable TX IRQ and
755 * disable TX DMA to let TX interrupt to send X-char */
756 ucr1 = imx_uart_readl(sport, UCR1);
757 ucr1 &= ~UCR1_TXDMAEN;
758 ucr1 |= UCR1_TRDYEN;
759 imx_uart_writel(sport, ucr1, UCR1);
760 return;
761 }
762
763 if (!uart_circ_empty(&port->state->xmit) &&
764 !uart_tx_stopped(port))
765 imx_uart_dma_tx(sport);
766 return;
767 }
768}
769
770static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id)
771{
772 struct imx_port *sport = dev_id;
773 u32 usr1;
774
775 imx_uart_writel(sport, USR1_RTSD, USR1);
776 usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
777 uart_handle_cts_change(&sport->port, !!usr1);
778 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
779
780 return IRQ_HANDLED;
781}
782
783static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
784{
785 struct imx_port *sport = dev_id;
786 irqreturn_t ret;
787
788 spin_lock(&sport->port.lock);
789
790 ret = __imx_uart_rtsint(irq, dev_id);
791
792 spin_unlock(&sport->port.lock);
793
794 return ret;
795}
796
797static irqreturn_t imx_uart_txint(int irq, void *dev_id)
798{
799 struct imx_port *sport = dev_id;
800
801 spin_lock(&sport->port.lock);
802 imx_uart_transmit_buffer(sport);
803 spin_unlock(&sport->port.lock);
804 return IRQ_HANDLED;
805}
806
807static irqreturn_t __imx_uart_rxint(int irq, void *dev_id)
808{
809 struct imx_port *sport = dev_id;
810 unsigned int rx, flg, ignored = 0;
811 struct tty_port *port = &sport->port.state->port;
812
813 while (imx_uart_readl(sport, USR2) & USR2_RDR) {
814 u32 usr2;
815
816 flg = TTY_NORMAL;
817 sport->port.icount.rx++;
818
819 rx = imx_uart_readl(sport, URXD0);
820
821 usr2 = imx_uart_readl(sport, USR2);
822 if (usr2 & USR2_BRCD) {
823 imx_uart_writel(sport, USR2_BRCD, USR2);
824 if (uart_handle_break(&sport->port))
825 continue;
826 }
827
828 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
829 continue;
830
831 if (unlikely(rx & URXD_ERR)) {
832 if (rx & URXD_BRK)
833 sport->port.icount.brk++;
834 else if (rx & URXD_PRERR)
835 sport->port.icount.parity++;
836 else if (rx & URXD_FRMERR)
837 sport->port.icount.frame++;
838 if (rx & URXD_OVRRUN)
839 sport->port.icount.overrun++;
840
841 if (rx & sport->port.ignore_status_mask) {
842 if (++ignored > 100)
843 goto out;
844 continue;
845 }
846
847 rx &= (sport->port.read_status_mask | 0xFF);
848
849 if (rx & URXD_BRK)
850 flg = TTY_BREAK;
851 else if (rx & URXD_PRERR)
852 flg = TTY_PARITY;
853 else if (rx & URXD_FRMERR)
854 flg = TTY_FRAME;
855 if (rx & URXD_OVRRUN)
856 flg = TTY_OVERRUN;
857
858 sport->port.sysrq = 0;
859 }
860
861 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
862 goto out;
863
864 if (tty_insert_flip_char(port, rx, flg) == 0)
865 sport->port.icount.buf_overrun++;
866 }
867
868out:
869 tty_flip_buffer_push(port);
870
871 return IRQ_HANDLED;
872}
873
874static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
875{
876 struct imx_port *sport = dev_id;
877 irqreturn_t ret;
878
879 spin_lock(&sport->port.lock);
880
881 ret = __imx_uart_rxint(irq, dev_id);
882
883 spin_unlock(&sport->port.lock);
884
885 return ret;
886}
887
888static void imx_uart_clear_rx_errors(struct imx_port *sport);
889
890/*
891 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
892 */
893static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
894{
895 unsigned int tmp = TIOCM_DSR;
896 unsigned usr1 = imx_uart_readl(sport, USR1);
897 unsigned usr2 = imx_uart_readl(sport, USR2);
898
899 if (usr1 & USR1_RTSS)
900 tmp |= TIOCM_CTS;
901
902 /* in DCE mode DCDIN is always 0 */
903 if (!(usr2 & USR2_DCDIN))
904 tmp |= TIOCM_CAR;
905
906 if (sport->dte_mode)
907 if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
908 tmp |= TIOCM_RI;
909
910 return tmp;
911}
912
913/*
914 * Handle any change of modem status signal since we were last called.
915 */
916static void imx_uart_mctrl_check(struct imx_port *sport)
917{
918 unsigned int status, changed;
919
920 status = imx_uart_get_hwmctrl(sport);
921 changed = status ^ sport->old_status;
922
923 if (changed == 0)
924 return;
925
926 sport->old_status = status;
927
928 if (changed & TIOCM_RI && status & TIOCM_RI)
929 sport->port.icount.rng++;
930 if (changed & TIOCM_DSR)
931 sport->port.icount.dsr++;
932 if (changed & TIOCM_CAR)
933 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
934 if (changed & TIOCM_CTS)
935 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
936
937 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
938}
939
940static irqreturn_t imx_uart_int(int irq, void *dev_id)
941{
942 struct imx_port *sport = dev_id;
943 unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
944 irqreturn_t ret = IRQ_NONE;
945
946 spin_lock(&sport->port.lock);
947
948 usr1 = imx_uart_readl(sport, USR1);
949 usr2 = imx_uart_readl(sport, USR2);
950 ucr1 = imx_uart_readl(sport, UCR1);
951 ucr2 = imx_uart_readl(sport, UCR2);
952 ucr3 = imx_uart_readl(sport, UCR3);
953 ucr4 = imx_uart_readl(sport, UCR4);
954
955 /*
956 * Even if a condition is true that can trigger an irq only handle it if
957 * the respective irq source is enabled. This prevents some undesired
958 * actions, for example if a character that sits in the RX FIFO and that
959 * should be fetched via DMA is tried to be fetched using PIO. Or the
960 * receiver is currently off and so reading from URXD0 results in an
961 * exception. So just mask the (raw) status bits for disabled irqs.
962 */
963 if ((ucr1 & UCR1_RRDYEN) == 0)
964 usr1 &= ~USR1_RRDY;
965 if ((ucr2 & UCR2_ATEN) == 0)
966 usr1 &= ~USR1_AGTIM;
967 if ((ucr1 & UCR1_TRDYEN) == 0)
968 usr1 &= ~USR1_TRDY;
969 if ((ucr4 & UCR4_TCEN) == 0)
970 usr2 &= ~USR2_TXDC;
971 if ((ucr3 & UCR3_DTRDEN) == 0)
972 usr1 &= ~USR1_DTRD;
973 if ((ucr1 & UCR1_RTSDEN) == 0)
974 usr1 &= ~USR1_RTSD;
975 if ((ucr3 & UCR3_AWAKEN) == 0)
976 usr1 &= ~USR1_AWAKE;
977 if ((ucr4 & UCR4_OREN) == 0)
978 usr2 &= ~USR2_ORE;
979
980 if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
981 imx_uart_writel(sport, USR1_AGTIM, USR1);
982
983 __imx_uart_rxint(irq, dev_id);
984 ret = IRQ_HANDLED;
985 }
986
987 if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
988 imx_uart_transmit_buffer(sport);
989 ret = IRQ_HANDLED;
990 }
991
992 if (usr1 & USR1_DTRD) {
993 imx_uart_writel(sport, USR1_DTRD, USR1);
994
995 imx_uart_mctrl_check(sport);
996
997 ret = IRQ_HANDLED;
998 }
999
1000 if (usr1 & USR1_RTSD) {
1001 __imx_uart_rtsint(irq, dev_id);
1002 ret = IRQ_HANDLED;
1003 }
1004
1005 if (usr1 & USR1_AWAKE) {
1006 imx_uart_writel(sport, USR1_AWAKE, USR1);
1007 ret = IRQ_HANDLED;
1008 }
1009
1010 if (usr2 & USR2_ORE) {
1011 sport->port.icount.overrun++;
1012 imx_uart_writel(sport, USR2_ORE, USR2);
1013 ret = IRQ_HANDLED;
1014 }
1015
1016 spin_unlock(&sport->port.lock);
1017
1018 return ret;
1019}
1020
1021/*
1022 * Return TIOCSER_TEMT when transmitter is not busy.
1023 */
1024static unsigned int imx_uart_tx_empty(struct uart_port *port)
1025{
1026 struct imx_port *sport = (struct imx_port *)port;
1027 unsigned int ret;
1028
1029 ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
1030
1031 /* If the TX DMA is working, return 0. */
1032 if (sport->dma_is_txing)
1033 ret = 0;
1034
1035 return ret;
1036}
1037
1038/* called with port.lock taken and irqs off */
1039static unsigned int imx_uart_get_mctrl(struct uart_port *port)
1040{
1041 struct imx_port *sport = (struct imx_port *)port;
1042 unsigned int ret = imx_uart_get_hwmctrl(sport);
1043
1044 mctrl_gpio_get(sport->gpios, &ret);
1045
1046 return ret;
1047}
1048
1049/* called with port.lock taken and irqs off */
1050static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
1051{
1052 struct imx_port *sport = (struct imx_port *)port;
1053 u32 ucr3, uts;
1054
1055 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
1056 u32 ucr2;
1057
1058 /*
1059 * Turn off autoRTS if RTS is lowered and restore autoRTS
1060 * setting if RTS is raised.
1061 */
1062 ucr2 = imx_uart_readl(sport, UCR2);
1063 ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
1064 if (mctrl & TIOCM_RTS) {
1065 ucr2 |= UCR2_CTS;
1066 /*
1067 * UCR2_IRTS is unset if and only if the port is
1068 * configured for CRTSCTS, so we use inverted UCR2_IRTS
1069 * to get the state to restore to.
1070 */
1071 if (!(ucr2 & UCR2_IRTS))
1072 ucr2 |= UCR2_CTSC;
1073 }
1074 imx_uart_writel(sport, ucr2, UCR2);
1075 }
1076
1077 ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
1078 if (!(mctrl & TIOCM_DTR))
1079 ucr3 |= UCR3_DSR;
1080 imx_uart_writel(sport, ucr3, UCR3);
1081
1082 uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
1083 if (mctrl & TIOCM_LOOP)
1084 uts |= UTS_LOOP;
1085 imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
1086
1087 mctrl_gpio_set(sport->gpios, mctrl);
1088}
1089
1090/*
1091 * Interrupts always disabled.
1092 */
1093static void imx_uart_break_ctl(struct uart_port *port, int break_state)
1094{
1095 struct imx_port *sport = (struct imx_port *)port;
1096 unsigned long flags;
1097 u32 ucr1;
1098
1099 spin_lock_irqsave(&sport->port.lock, flags);
1100
1101 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
1102
1103 if (break_state != 0)
1104 ucr1 |= UCR1_SNDBRK;
1105
1106 imx_uart_writel(sport, ucr1, UCR1);
1107
1108 spin_unlock_irqrestore(&sport->port.lock, flags);
1109}
1110
1111/*
1112 * This is our per-port timeout handler, for checking the
1113 * modem status signals.
1114 */
1115static void imx_uart_timeout(struct timer_list *t)
1116{
1117 struct imx_port *sport = from_timer(sport, t, timer);
1118 unsigned long flags;
1119
1120 if (sport->port.state) {
1121 spin_lock_irqsave(&sport->port.lock, flags);
1122 imx_uart_mctrl_check(sport);
1123 spin_unlock_irqrestore(&sport->port.lock, flags);
1124
1125 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
1126 }
1127}
1128
1129/*
1130 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
1131 * [1] the RX DMA buffer is full.
1132 * [2] the aging timer expires
1133 *
1134 * Condition [2] is triggered when a character has been sitting in the FIFO
1135 * for at least 8 byte durations.
1136 */
1137static void imx_uart_dma_rx_callback(void *data)
1138{
1139 struct imx_port *sport = data;
1140 struct dma_chan *chan = sport->dma_chan_rx;
1141 struct scatterlist *sgl = &sport->rx_sgl;
1142 struct tty_port *port = &sport->port.state->port;
1143 struct dma_tx_state state;
1144 struct circ_buf *rx_ring = &sport->rx_ring;
1145 enum dma_status status;
1146 unsigned int w_bytes = 0;
1147 unsigned int r_bytes;
1148 unsigned int bd_size;
1149
1150 status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
1151
1152 if (status == DMA_ERROR) {
1153 imx_uart_clear_rx_errors(sport);
1154 return;
1155 }
1156
1157 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
1158
1159 /*
1160 * The state-residue variable represents the empty space
1161 * relative to the entire buffer. Taking this in consideration
1162 * the head is always calculated base on the buffer total
1163 * length - DMA transaction residue. The UART script from the
1164 * SDMA firmware will jump to the next buffer descriptor,
1165 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
1166 * Taking this in consideration the tail is always at the
1167 * beginning of the buffer descriptor that contains the head.
1168 */
1169
1170 /* Calculate the head */
1171 rx_ring->head = sg_dma_len(sgl) - state.residue;
1172
1173 /* Calculate the tail. */
1174 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1175 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1176
1177 if (rx_ring->head <= sg_dma_len(sgl) &&
1178 rx_ring->head > rx_ring->tail) {
1179
1180 /* Move data from tail to head */
1181 r_bytes = rx_ring->head - rx_ring->tail;
1182
1183 /* CPU claims ownership of RX DMA buffer */
1184 dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1185 DMA_FROM_DEVICE);
1186
1187 w_bytes = tty_insert_flip_string(port,
1188 sport->rx_buf + rx_ring->tail, r_bytes);
1189
1190 /* UART retrieves ownership of RX DMA buffer */
1191 dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1192 DMA_FROM_DEVICE);
1193
1194 if (w_bytes != r_bytes)
1195 sport->port.icount.buf_overrun++;
1196
1197 sport->port.icount.rx += w_bytes;
1198 } else {
1199 WARN_ON(rx_ring->head > sg_dma_len(sgl));
1200 WARN_ON(rx_ring->head <= rx_ring->tail);
1201 }
1202 }
1203
1204 if (w_bytes) {
1205 tty_flip_buffer_push(port);
1206 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1207 }
1208}
1209
1210/* RX DMA buffer periods */
1211#define RX_DMA_PERIODS 16
1212#define RX_BUF_SIZE (RX_DMA_PERIODS * PAGE_SIZE / 4)
1213
1214static int imx_uart_start_rx_dma(struct imx_port *sport)
1215{
1216 struct scatterlist *sgl = &sport->rx_sgl;
1217 struct dma_chan *chan = sport->dma_chan_rx;
1218 struct device *dev = sport->port.dev;
1219 struct dma_async_tx_descriptor *desc;
1220 int ret;
1221
1222 sport->rx_ring.head = 0;
1223 sport->rx_ring.tail = 0;
1224 sport->rx_periods = RX_DMA_PERIODS;
1225
1226 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1227 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1228 if (ret == 0) {
1229 dev_err(dev, "DMA mapping error for RX.\n");
1230 return -EINVAL;
1231 }
1232
1233 desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1234 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1235 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1236
1237 if (!desc) {
1238 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1239 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1240 return -EINVAL;
1241 }
1242 desc->callback = imx_uart_dma_rx_callback;
1243 desc->callback_param = sport;
1244
1245 dev_dbg(dev, "RX: prepare for the DMA.\n");
1246 sport->dma_is_rxing = 1;
1247 sport->rx_cookie = dmaengine_submit(desc);
1248 dma_async_issue_pending(chan);
1249 return 0;
1250}
1251
1252static void imx_uart_clear_rx_errors(struct imx_port *sport)
1253{
1254 struct tty_port *port = &sport->port.state->port;
1255 u32 usr1, usr2;
1256
1257 usr1 = imx_uart_readl(sport, USR1);
1258 usr2 = imx_uart_readl(sport, USR2);
1259
1260 if (usr2 & USR2_BRCD) {
1261 sport->port.icount.brk++;
1262 imx_uart_writel(sport, USR2_BRCD, USR2);
1263 uart_handle_break(&sport->port);
1264 if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
1265 sport->port.icount.buf_overrun++;
1266 tty_flip_buffer_push(port);
1267 } else {
1268 if (usr1 & USR1_FRAMERR) {
1269 sport->port.icount.frame++;
1270 imx_uart_writel(sport, USR1_FRAMERR, USR1);
1271 } else if (usr1 & USR1_PARITYERR) {
1272 sport->port.icount.parity++;
1273 imx_uart_writel(sport, USR1_PARITYERR, USR1);
1274 }
1275 }
1276
1277 if (usr2 & USR2_ORE) {
1278 sport->port.icount.overrun++;
1279 imx_uart_writel(sport, USR2_ORE, USR2);
1280 }
1281
1282}
1283
1284#define TXTL_DEFAULT 2 /* reset default */
1285#define RXTL_DEFAULT 1 /* reset default */
1286#define TXTL_DMA 8 /* DMA burst setting */
1287#define RXTL_DMA 9 /* DMA burst setting */
1288
1289static void imx_uart_setup_ufcr(struct imx_port *sport,
1290 unsigned char txwl, unsigned char rxwl)
1291{
1292 unsigned int val;
1293
1294 /* set receiver / transmitter trigger level */
1295 val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1296 val |= txwl << UFCR_TXTL_SHF | rxwl;
1297 imx_uart_writel(sport, val, UFCR);
1298}
1299
1300static void imx_uart_dma_exit(struct imx_port *sport)
1301{
1302 if (sport->dma_chan_rx) {
1303 dmaengine_terminate_sync(sport->dma_chan_rx);
1304 dma_release_channel(sport->dma_chan_rx);
1305 sport->dma_chan_rx = NULL;
1306 sport->rx_cookie = -EINVAL;
1307 kfree(sport->rx_buf);
1308 sport->rx_buf = NULL;
1309 }
1310
1311 if (sport->dma_chan_tx) {
1312 dmaengine_terminate_sync(sport->dma_chan_tx);
1313 dma_release_channel(sport->dma_chan_tx);
1314 sport->dma_chan_tx = NULL;
1315 }
1316}
1317
1318static int imx_uart_dma_init(struct imx_port *sport)
1319{
1320 struct dma_slave_config slave_config = {};
1321 struct device *dev = sport->port.dev;
1322 int ret;
1323
1324 /* Prepare for RX : */
1325 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1326 if (!sport->dma_chan_rx) {
1327 dev_dbg(dev, "cannot get the DMA channel.\n");
1328 ret = -EINVAL;
1329 goto err;
1330 }
1331
1332 slave_config.direction = DMA_DEV_TO_MEM;
1333 slave_config.src_addr = sport->port.mapbase + URXD0;
1334 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1335 /* one byte less than the watermark level to enable the aging timer */
1336 slave_config.src_maxburst = RXTL_DMA - 1;
1337 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1338 if (ret) {
1339 dev_err(dev, "error in RX dma configuration.\n");
1340 goto err;
1341 }
1342
1343 sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
1344 if (!sport->rx_buf) {
1345 ret = -ENOMEM;
1346 goto err;
1347 }
1348 sport->rx_ring.buf = sport->rx_buf;
1349
1350 /* Prepare for TX : */
1351 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1352 if (!sport->dma_chan_tx) {
1353 dev_err(dev, "cannot get the TX DMA channel!\n");
1354 ret = -EINVAL;
1355 goto err;
1356 }
1357
1358 slave_config.direction = DMA_MEM_TO_DEV;
1359 slave_config.dst_addr = sport->port.mapbase + URTX0;
1360 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1361 slave_config.dst_maxburst = TXTL_DMA;
1362 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1363 if (ret) {
1364 dev_err(dev, "error in TX dma configuration.");
1365 goto err;
1366 }
1367
1368 return 0;
1369err:
1370 imx_uart_dma_exit(sport);
1371 return ret;
1372}
1373
1374static void imx_uart_enable_dma(struct imx_port *sport)
1375{
1376 u32 ucr1;
1377
1378 imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1379
1380 /* set UCR1 */
1381 ucr1 = imx_uart_readl(sport, UCR1);
1382 ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
1383 imx_uart_writel(sport, ucr1, UCR1);
1384
1385 sport->dma_is_enabled = 1;
1386}
1387
1388static void imx_uart_disable_dma(struct imx_port *sport)
1389{
1390 u32 ucr1;
1391
1392 /* clear UCR1 */
1393 ucr1 = imx_uart_readl(sport, UCR1);
1394 ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
1395 imx_uart_writel(sport, ucr1, UCR1);
1396
1397 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1398
1399 sport->dma_is_enabled = 0;
1400}
1401
1402/* half the RX buffer size */
1403#define CTSTL 16
1404
1405static int imx_uart_startup(struct uart_port *port)
1406{
1407 struct imx_port *sport = (struct imx_port *)port;
1408 int retval, i;
1409 unsigned long flags;
1410 int dma_is_inited = 0;
1411 u32 ucr1, ucr2, ucr3, ucr4;
1412
1413 retval = clk_prepare_enable(sport->clk_per);
1414 if (retval)
1415 return retval;
1416 retval = clk_prepare_enable(sport->clk_ipg);
1417 if (retval) {
1418 clk_disable_unprepare(sport->clk_per);
1419 return retval;
1420 }
1421
1422 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1423
1424 /* disable the DREN bit (Data Ready interrupt enable) before
1425 * requesting IRQs
1426 */
1427 ucr4 = imx_uart_readl(sport, UCR4);
1428
1429 /* set the trigger level for CTS */
1430 ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1431 ucr4 |= CTSTL << UCR4_CTSTL_SHF;
1432
1433 imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
1434
1435 /* Can we enable the DMA support? */
1436 if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
1437 dma_is_inited = 1;
1438
1439 spin_lock_irqsave(&sport->port.lock, flags);
1440 /* Reset fifo's and state machines */
1441 i = 100;
1442
1443 ucr2 = imx_uart_readl(sport, UCR2);
1444 ucr2 &= ~UCR2_SRST;
1445 imx_uart_writel(sport, ucr2, UCR2);
1446
1447 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1448 udelay(1);
1449
1450 /*
1451 * Finally, clear and enable interrupts
1452 */
1453 imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
1454 imx_uart_writel(sport, USR2_ORE, USR2);
1455
1456 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
1457 ucr1 |= UCR1_UARTEN;
1458 if (sport->have_rtscts)
1459 ucr1 |= UCR1_RTSDEN;
1460
1461 imx_uart_writel(sport, ucr1, UCR1);
1462
1463 ucr4 = imx_uart_readl(sport, UCR4) & ~(UCR4_OREN | UCR4_INVR);
1464 if (!sport->dma_is_enabled)
1465 ucr4 |= UCR4_OREN;
1466 if (sport->inverted_rx)
1467 ucr4 |= UCR4_INVR;
1468 imx_uart_writel(sport, ucr4, UCR4);
1469
1470 ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_INVT;
1471 /*
1472 * configure tx polarity before enabling tx
1473 */
1474 if (sport->inverted_tx)
1475 ucr3 |= UCR3_INVT;
1476
1477 if (!imx_uart_is_imx1(sport)) {
1478 ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1479
1480 if (sport->dte_mode)
1481 /* disable broken interrupts */
1482 ucr3 &= ~(UCR3_RI | UCR3_DCD);
1483 }
1484 imx_uart_writel(sport, ucr3, UCR3);
1485
1486 ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
1487 ucr2 |= (UCR2_RXEN | UCR2_TXEN);
1488 if (!sport->have_rtscts)
1489 ucr2 |= UCR2_IRTS;
1490 /*
1491 * make sure the edge sensitive RTS-irq is disabled,
1492 * we're using RTSD instead.
1493 */
1494 if (!imx_uart_is_imx1(sport))
1495 ucr2 &= ~UCR2_RTSEN;
1496 imx_uart_writel(sport, ucr2, UCR2);
1497
1498 /*
1499 * Enable modem status interrupts
1500 */
1501 imx_uart_enable_ms(&sport->port);
1502
1503 if (dma_is_inited) {
1504 imx_uart_enable_dma(sport);
1505 imx_uart_start_rx_dma(sport);
1506 } else {
1507 ucr1 = imx_uart_readl(sport, UCR1);
1508 ucr1 |= UCR1_RRDYEN;
1509 imx_uart_writel(sport, ucr1, UCR1);
1510
1511 ucr2 = imx_uart_readl(sport, UCR2);
1512 ucr2 |= UCR2_ATEN;
1513 imx_uart_writel(sport, ucr2, UCR2);
1514 }
1515
1516 spin_unlock_irqrestore(&sport->port.lock, flags);
1517
1518 return 0;
1519}
1520
1521static void imx_uart_shutdown(struct uart_port *port)
1522{
1523 struct imx_port *sport = (struct imx_port *)port;
1524 unsigned long flags;
1525 u32 ucr1, ucr2, ucr4;
1526
1527 if (sport->dma_is_enabled) {
1528 dmaengine_terminate_sync(sport->dma_chan_tx);
1529 if (sport->dma_is_txing) {
1530 dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
1531 sport->dma_tx_nents, DMA_TO_DEVICE);
1532 sport->dma_is_txing = 0;
1533 }
1534 dmaengine_terminate_sync(sport->dma_chan_rx);
1535 if (sport->dma_is_rxing) {
1536 dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
1537 1, DMA_FROM_DEVICE);
1538 sport->dma_is_rxing = 0;
1539 }
1540
1541 spin_lock_irqsave(&sport->port.lock, flags);
1542 imx_uart_stop_tx(port);
1543 imx_uart_stop_rx(port);
1544 imx_uart_disable_dma(sport);
1545 spin_unlock_irqrestore(&sport->port.lock, flags);
1546 imx_uart_dma_exit(sport);
1547 }
1548
1549 mctrl_gpio_disable_ms(sport->gpios);
1550
1551 spin_lock_irqsave(&sport->port.lock, flags);
1552 ucr2 = imx_uart_readl(sport, UCR2);
1553 ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
1554 imx_uart_writel(sport, ucr2, UCR2);
1555
1556 ucr4 = imx_uart_readl(sport, UCR4);
1557 ucr4 &= ~UCR4_OREN;
1558 imx_uart_writel(sport, ucr4, UCR4);
1559 spin_unlock_irqrestore(&sport->port.lock, flags);
1560
1561 /*
1562 * Stop our timer.
1563 */
1564 del_timer_sync(&sport->timer);
1565
1566 /*
1567 * Disable all interrupts, port and break condition.
1568 */
1569
1570 spin_lock_irqsave(&sport->port.lock, flags);
1571 ucr1 = imx_uart_readl(sport, UCR1);
1572 ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
1573
1574 imx_uart_writel(sport, ucr1, UCR1);
1575 spin_unlock_irqrestore(&sport->port.lock, flags);
1576
1577 clk_disable_unprepare(sport->clk_per);
1578 clk_disable_unprepare(sport->clk_ipg);
1579}
1580
1581/* called with port.lock taken and irqs off */
1582static void imx_uart_flush_buffer(struct uart_port *port)
1583{
1584 struct imx_port *sport = (struct imx_port *)port;
1585 struct scatterlist *sgl = &sport->tx_sgl[0];
1586 u32 ucr2;
1587 int i = 100, ubir, ubmr, uts;
1588
1589 if (!sport->dma_chan_tx)
1590 return;
1591
1592 sport->tx_bytes = 0;
1593 dmaengine_terminate_all(sport->dma_chan_tx);
1594 if (sport->dma_is_txing) {
1595 u32 ucr1;
1596
1597 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1598 DMA_TO_DEVICE);
1599 ucr1 = imx_uart_readl(sport, UCR1);
1600 ucr1 &= ~UCR1_TXDMAEN;
1601 imx_uart_writel(sport, ucr1, UCR1);
1602 sport->dma_is_txing = 0;
1603 }
1604
1605 /*
1606 * According to the Reference Manual description of the UART SRST bit:
1607 *
1608 * "Reset the transmit and receive state machines,
1609 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1610 * and UTS[6-3]".
1611 *
1612 * We don't need to restore the old values from USR1, USR2, URXD and
1613 * UTXD. UBRC is read only, so only save/restore the other three
1614 * registers.
1615 */
1616 ubir = imx_uart_readl(sport, UBIR);
1617 ubmr = imx_uart_readl(sport, UBMR);
1618 uts = imx_uart_readl(sport, IMX21_UTS);
1619
1620 ucr2 = imx_uart_readl(sport, UCR2);
1621 ucr2 &= ~UCR2_SRST;
1622 imx_uart_writel(sport, ucr2, UCR2);
1623
1624 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1625 udelay(1);
1626
1627 /* Restore the registers */
1628 imx_uart_writel(sport, ubir, UBIR);
1629 imx_uart_writel(sport, ubmr, UBMR);
1630 imx_uart_writel(sport, uts, IMX21_UTS);
1631}
1632
1633static void
1634imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
1635 struct ktermios *old)
1636{
1637 struct imx_port *sport = (struct imx_port *)port;
1638 unsigned long flags;
1639 u32 ucr2, old_ucr2, ufcr;
1640 unsigned int baud, quot;
1641 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1642 unsigned long div;
1643 unsigned long num, denom, old_ubir, old_ubmr;
1644 uint64_t tdiv64;
1645
1646 /*
1647 * We only support CS7 and CS8.
1648 */
1649 while ((termios->c_cflag & CSIZE) != CS7 &&
1650 (termios->c_cflag & CSIZE) != CS8) {
1651 termios->c_cflag &= ~CSIZE;
1652 termios->c_cflag |= old_csize;
1653 old_csize = CS8;
1654 }
1655
1656 del_timer_sync(&sport->timer);
1657
1658 /*
1659 * Ask the core to calculate the divisor for us.
1660 */
1661 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1662 quot = uart_get_divisor(port, baud);
1663
1664 spin_lock_irqsave(&sport->port.lock, flags);
1665
1666 /*
1667 * Read current UCR2 and save it for future use, then clear all the bits
1668 * except those we will or may need to preserve.
1669 */
1670 old_ucr2 = imx_uart_readl(sport, UCR2);
1671 ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
1672
1673 ucr2 |= UCR2_SRST | UCR2_IRTS;
1674 if ((termios->c_cflag & CSIZE) == CS8)
1675 ucr2 |= UCR2_WS;
1676
1677 if (!sport->have_rtscts)
1678 termios->c_cflag &= ~CRTSCTS;
1679
1680 if (port->rs485.flags & SER_RS485_ENABLED) {
1681 /*
1682 * RTS is mandatory for rs485 operation, so keep
1683 * it under manual control and keep transmitter
1684 * disabled.
1685 */
1686 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1687 imx_uart_rts_active(sport, &ucr2);
1688 else
1689 imx_uart_rts_inactive(sport, &ucr2);
1690
1691 } else if (termios->c_cflag & CRTSCTS) {
1692 /*
1693 * Only let receiver control RTS output if we were not requested
1694 * to have RTS inactive (which then should take precedence).
1695 */
1696 if (ucr2 & UCR2_CTS)
1697 ucr2 |= UCR2_CTSC;
1698 }
1699
1700 if (termios->c_cflag & CRTSCTS)
1701 ucr2 &= ~UCR2_IRTS;
1702 if (termios->c_cflag & CSTOPB)
1703 ucr2 |= UCR2_STPB;
1704 if (termios->c_cflag & PARENB) {
1705 ucr2 |= UCR2_PREN;
1706 if (termios->c_cflag & PARODD)
1707 ucr2 |= UCR2_PROE;
1708 }
1709
1710 sport->port.read_status_mask = 0;
1711 if (termios->c_iflag & INPCK)
1712 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1713 if (termios->c_iflag & (BRKINT | PARMRK))
1714 sport->port.read_status_mask |= URXD_BRK;
1715
1716 /*
1717 * Characters to ignore
1718 */
1719 sport->port.ignore_status_mask = 0;
1720 if (termios->c_iflag & IGNPAR)
1721 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1722 if (termios->c_iflag & IGNBRK) {
1723 sport->port.ignore_status_mask |= URXD_BRK;
1724 /*
1725 * If we're ignoring parity and break indicators,
1726 * ignore overruns too (for real raw support).
1727 */
1728 if (termios->c_iflag & IGNPAR)
1729 sport->port.ignore_status_mask |= URXD_OVRRUN;
1730 }
1731
1732 if ((termios->c_cflag & CREAD) == 0)
1733 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1734
1735 /*
1736 * Update the per-port timeout.
1737 */
1738 uart_update_timeout(port, termios->c_cflag, baud);
1739
1740 /* custom-baudrate handling */
1741 div = sport->port.uartclk / (baud * 16);
1742 if (baud == 38400 && quot != div)
1743 baud = sport->port.uartclk / (quot * 16);
1744
1745 div = sport->port.uartclk / (baud * 16);
1746 if (div > 7)
1747 div = 7;
1748 if (!div)
1749 div = 1;
1750
1751 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1752 1 << 16, 1 << 16, &num, &denom);
1753
1754 tdiv64 = sport->port.uartclk;
1755 tdiv64 *= num;
1756 do_div(tdiv64, denom * 16 * div);
1757 tty_termios_encode_baud_rate(termios,
1758 (speed_t)tdiv64, (speed_t)tdiv64);
1759
1760 num -= 1;
1761 denom -= 1;
1762
1763 ufcr = imx_uart_readl(sport, UFCR);
1764 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1765 imx_uart_writel(sport, ufcr, UFCR);
1766
1767 /*
1768 * Two registers below should always be written both and in this
1769 * particular order. One consequence is that we need to check if any of
1770 * them changes and then update both. We do need the check for change
1771 * as even writing the same values seem to "restart"
1772 * transmission/receiving logic in the hardware, that leads to data
1773 * breakage even when rate doesn't in fact change. E.g., user switches
1774 * RTS/CTS handshake and suddenly gets broken bytes.
1775 */
1776 old_ubir = imx_uart_readl(sport, UBIR);
1777 old_ubmr = imx_uart_readl(sport, UBMR);
1778 if (old_ubir != num || old_ubmr != denom) {
1779 imx_uart_writel(sport, num, UBIR);
1780 imx_uart_writel(sport, denom, UBMR);
1781 }
1782
1783 if (!imx_uart_is_imx1(sport))
1784 imx_uart_writel(sport, sport->port.uartclk / div / 1000,
1785 IMX21_ONEMS);
1786
1787 imx_uart_writel(sport, ucr2, UCR2);
1788
1789 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1790 imx_uart_enable_ms(&sport->port);
1791
1792 spin_unlock_irqrestore(&sport->port.lock, flags);
1793}
1794
1795static const char *imx_uart_type(struct uart_port *port)
1796{
1797 struct imx_port *sport = (struct imx_port *)port;
1798
1799 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1800}
1801
1802/*
1803 * Configure/autoconfigure the port.
1804 */
1805static void imx_uart_config_port(struct uart_port *port, int flags)
1806{
1807 struct imx_port *sport = (struct imx_port *)port;
1808
1809 if (flags & UART_CONFIG_TYPE)
1810 sport->port.type = PORT_IMX;
1811}
1812
1813/*
1814 * Verify the new serial_struct (for TIOCSSERIAL).
1815 * The only change we allow are to the flags and type, and
1816 * even then only between PORT_IMX and PORT_UNKNOWN
1817 */
1818static int
1819imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
1820{
1821 struct imx_port *sport = (struct imx_port *)port;
1822 int ret = 0;
1823
1824 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1825 ret = -EINVAL;
1826 if (sport->port.irq != ser->irq)
1827 ret = -EINVAL;
1828 if (ser->io_type != UPIO_MEM)
1829 ret = -EINVAL;
1830 if (sport->port.uartclk / 16 != ser->baud_base)
1831 ret = -EINVAL;
1832 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1833 ret = -EINVAL;
1834 if (sport->port.iobase != ser->port)
1835 ret = -EINVAL;
1836 if (ser->hub6 != 0)
1837 ret = -EINVAL;
1838 return ret;
1839}
1840
1841#if defined(CONFIG_CONSOLE_POLL)
1842
1843static int imx_uart_poll_init(struct uart_port *port)
1844{
1845 struct imx_port *sport = (struct imx_port *)port;
1846 unsigned long flags;
1847 u32 ucr1, ucr2;
1848 int retval;
1849
1850 retval = clk_prepare_enable(sport->clk_ipg);
1851 if (retval)
1852 return retval;
1853 retval = clk_prepare_enable(sport->clk_per);
1854 if (retval)
1855 clk_disable_unprepare(sport->clk_ipg);
1856
1857 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1858
1859 spin_lock_irqsave(&sport->port.lock, flags);
1860
1861 /*
1862 * Be careful about the order of enabling bits here. First enable the
1863 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
1864 * This prevents that a character that already sits in the RX fifo is
1865 * triggering an irq but the try to fetch it from there results in an
1866 * exception because UARTEN or RXEN is still off.
1867 */
1868 ucr1 = imx_uart_readl(sport, UCR1);
1869 ucr2 = imx_uart_readl(sport, UCR2);
1870
1871 if (imx_uart_is_imx1(sport))
1872 ucr1 |= IMX1_UCR1_UARTCLKEN;
1873
1874 ucr1 |= UCR1_UARTEN;
1875 ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
1876
1877 ucr2 |= UCR2_RXEN;
1878 ucr2 &= ~UCR2_ATEN;
1879
1880 imx_uart_writel(sport, ucr1, UCR1);
1881 imx_uart_writel(sport, ucr2, UCR2);
1882
1883 /* now enable irqs */
1884 imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
1885 imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
1886
1887 spin_unlock_irqrestore(&sport->port.lock, flags);
1888
1889 return 0;
1890}
1891
1892static int imx_uart_poll_get_char(struct uart_port *port)
1893{
1894 struct imx_port *sport = (struct imx_port *)port;
1895 if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
1896 return NO_POLL_CHAR;
1897
1898 return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
1899}
1900
1901static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
1902{
1903 struct imx_port *sport = (struct imx_port *)port;
1904 unsigned int status;
1905
1906 /* drain */
1907 do {
1908 status = imx_uart_readl(sport, USR1);
1909 } while (~status & USR1_TRDY);
1910
1911 /* write */
1912 imx_uart_writel(sport, c, URTX0);
1913
1914 /* flush */
1915 do {
1916 status = imx_uart_readl(sport, USR2);
1917 } while (~status & USR2_TXDC);
1918}
1919#endif
1920
1921/* called with port.lock taken and irqs off or from .probe without locking */
1922static int imx_uart_rs485_config(struct uart_port *port,
1923 struct serial_rs485 *rs485conf)
1924{
1925 struct imx_port *sport = (struct imx_port *)port;
1926 u32 ucr2;
1927
1928 /* RTS is required to control the transmitter */
1929 if (!sport->have_rtscts && !sport->have_rtsgpio)
1930 rs485conf->flags &= ~SER_RS485_ENABLED;
1931
1932 if (rs485conf->flags & SER_RS485_ENABLED) {
1933 /* Enable receiver if low-active RTS signal is requested */
1934 if (sport->have_rtscts && !sport->have_rtsgpio &&
1935 !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
1936 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1937
1938 /* disable transmitter */
1939 ucr2 = imx_uart_readl(sport, UCR2);
1940 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1941 imx_uart_rts_active(sport, &ucr2);
1942 else
1943 imx_uart_rts_inactive(sport, &ucr2);
1944 imx_uart_writel(sport, ucr2, UCR2);
1945 }
1946
1947 /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1948 if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1949 rs485conf->flags & SER_RS485_RX_DURING_TX)
1950 imx_uart_start_rx(port);
1951
1952 port->rs485 = *rs485conf;
1953
1954 return 0;
1955}
1956
1957static const struct uart_ops imx_uart_pops = {
1958 .tx_empty = imx_uart_tx_empty,
1959 .set_mctrl = imx_uart_set_mctrl,
1960 .get_mctrl = imx_uart_get_mctrl,
1961 .stop_tx = imx_uart_stop_tx,
1962 .start_tx = imx_uart_start_tx,
1963 .stop_rx = imx_uart_stop_rx,
1964 .enable_ms = imx_uart_enable_ms,
1965 .break_ctl = imx_uart_break_ctl,
1966 .startup = imx_uart_startup,
1967 .shutdown = imx_uart_shutdown,
1968 .flush_buffer = imx_uart_flush_buffer,
1969 .set_termios = imx_uart_set_termios,
1970 .type = imx_uart_type,
1971 .config_port = imx_uart_config_port,
1972 .verify_port = imx_uart_verify_port,
1973#if defined(CONFIG_CONSOLE_POLL)
1974 .poll_init = imx_uart_poll_init,
1975 .poll_get_char = imx_uart_poll_get_char,
1976 .poll_put_char = imx_uart_poll_put_char,
1977#endif
1978};
1979
1980static struct imx_port *imx_uart_ports[UART_NR];
1981
1982#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
1983static void imx_uart_console_putchar(struct uart_port *port, int ch)
1984{
1985 struct imx_port *sport = (struct imx_port *)port;
1986
1987 while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
1988 barrier();
1989
1990 imx_uart_writel(sport, ch, URTX0);
1991}
1992
1993/*
1994 * Interrupts are disabled on entering
1995 */
1996static void
1997imx_uart_console_write(struct console *co, const char *s, unsigned int count)
1998{
1999 struct imx_port *sport = imx_uart_ports[co->index];
2000 struct imx_port_ucrs old_ucr;
2001 unsigned int ucr1;
2002 unsigned long flags = 0;
2003 int locked = 1;
2004 int retval;
2005
2006 retval = clk_enable(sport->clk_per);
2007 if (retval)
2008 return;
2009 retval = clk_enable(sport->clk_ipg);
2010 if (retval) {
2011 clk_disable(sport->clk_per);
2012 return;
2013 }
2014
2015 if (sport->port.sysrq)
2016 locked = 0;
2017 else if (oops_in_progress)
2018 locked = spin_trylock_irqsave(&sport->port.lock, flags);
2019 else
2020 spin_lock_irqsave(&sport->port.lock, flags);
2021
2022 /*
2023 * First, save UCR1/2/3 and then disable interrupts
2024 */
2025 imx_uart_ucrs_save(sport, &old_ucr);
2026 ucr1 = old_ucr.ucr1;
2027
2028 if (imx_uart_is_imx1(sport))
2029 ucr1 |= IMX1_UCR1_UARTCLKEN;
2030 ucr1 |= UCR1_UARTEN;
2031 ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN);
2032
2033 imx_uart_writel(sport, ucr1, UCR1);
2034
2035 imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
2036
2037 uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
2038
2039 /*
2040 * Finally, wait for transmitter to become empty
2041 * and restore UCR1/2/3
2042 */
2043 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
2044
2045 imx_uart_ucrs_restore(sport, &old_ucr);
2046
2047 if (locked)
2048 spin_unlock_irqrestore(&sport->port.lock, flags);
2049
2050 clk_disable(sport->clk_ipg);
2051 clk_disable(sport->clk_per);
2052}
2053
2054/*
2055 * If the port was already initialised (eg, by a boot loader),
2056 * try to determine the current setup.
2057 */
2058static void __init
2059imx_uart_console_get_options(struct imx_port *sport, int *baud,
2060 int *parity, int *bits)
2061{
2062
2063 if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
2064 /* ok, the port was enabled */
2065 unsigned int ucr2, ubir, ubmr, uartclk;
2066 unsigned int baud_raw;
2067 unsigned int ucfr_rfdiv;
2068
2069 ucr2 = imx_uart_readl(sport, UCR2);
2070
2071 *parity = 'n';
2072 if (ucr2 & UCR2_PREN) {
2073 if (ucr2 & UCR2_PROE)
2074 *parity = 'o';
2075 else
2076 *parity = 'e';
2077 }
2078
2079 if (ucr2 & UCR2_WS)
2080 *bits = 8;
2081 else
2082 *bits = 7;
2083
2084 ubir = imx_uart_readl(sport, UBIR) & 0xffff;
2085 ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
2086
2087 ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
2088 if (ucfr_rfdiv == 6)
2089 ucfr_rfdiv = 7;
2090 else
2091 ucfr_rfdiv = 6 - ucfr_rfdiv;
2092
2093 uartclk = clk_get_rate(sport->clk_per);
2094 uartclk /= ucfr_rfdiv;
2095
2096 { /*
2097 * The next code provides exact computation of
2098 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
2099 * without need of float support or long long division,
2100 * which would be required to prevent 32bit arithmetic overflow
2101 */
2102 unsigned int mul = ubir + 1;
2103 unsigned int div = 16 * (ubmr + 1);
2104 unsigned int rem = uartclk % div;
2105
2106 baud_raw = (uartclk / div) * mul;
2107 baud_raw += (rem * mul + div / 2) / div;
2108 *baud = (baud_raw + 50) / 100 * 100;
2109 }
2110
2111 if (*baud != baud_raw)
2112 dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
2113 baud_raw, *baud);
2114 }
2115}
2116
2117static int __init
2118imx_uart_console_setup(struct console *co, char *options)
2119{
2120 struct imx_port *sport;
2121 int baud = 9600;
2122 int bits = 8;
2123 int parity = 'n';
2124 int flow = 'n';
2125 int retval;
2126
2127 /*
2128 * Check whether an invalid uart number has been specified, and
2129 * if so, search for the first available port that does have
2130 * console support.
2131 */
2132 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
2133 co->index = 0;
2134 sport = imx_uart_ports[co->index];
2135 if (sport == NULL)
2136 return -ENODEV;
2137
2138 /* For setting the registers, we only need to enable the ipg clock. */
2139 retval = clk_prepare_enable(sport->clk_ipg);
2140 if (retval)
2141 goto error_console;
2142
2143 if (options)
2144 uart_parse_options(options, &baud, &parity, &bits, &flow);
2145 else
2146 imx_uart_console_get_options(sport, &baud, &parity, &bits);
2147
2148 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
2149
2150 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
2151
2152 clk_disable(sport->clk_ipg);
2153 if (retval) {
2154 clk_unprepare(sport->clk_ipg);
2155 goto error_console;
2156 }
2157
2158 retval = clk_prepare(sport->clk_per);
2159 if (retval)
2160 clk_unprepare(sport->clk_ipg);
2161
2162error_console:
2163 return retval;
2164}
2165
2166static struct uart_driver imx_uart_uart_driver;
2167static struct console imx_uart_console = {
2168 .name = DEV_NAME,
2169 .write = imx_uart_console_write,
2170 .device = uart_console_device,
2171 .setup = imx_uart_console_setup,
2172 .flags = CON_PRINTBUFFER,
2173 .index = -1,
2174 .data = &imx_uart_uart_driver,
2175};
2176
2177#define IMX_CONSOLE &imx_uart_console
2178
2179#else
2180#define IMX_CONSOLE NULL
2181#endif
2182
2183static struct uart_driver imx_uart_uart_driver = {
2184 .owner = THIS_MODULE,
2185 .driver_name = DRIVER_NAME,
2186 .dev_name = DEV_NAME,
2187 .major = SERIAL_IMX_MAJOR,
2188 .minor = MINOR_START,
2189 .nr = ARRAY_SIZE(imx_uart_ports),
2190 .cons = IMX_CONSOLE,
2191};
2192
2193#ifdef CONFIG_OF
2194/*
2195 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2196 * could successfully get all information from dt or a negative errno.
2197 */
2198static int imx_uart_probe_dt(struct imx_port *sport,
2199 struct platform_device *pdev)
2200{
2201 struct device_node *np = pdev->dev.of_node;
2202 int ret;
2203
2204 sport->devdata = of_device_get_match_data(&pdev->dev);
2205 if (!sport->devdata)
2206 /* no device tree device */
2207 return 1;
2208
2209 ret = of_alias_get_id(np, "serial");
2210 if (ret < 0) {
2211 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2212 return ret;
2213 }
2214 sport->port.line = ret;
2215
2216 if (of_get_property(np, "uart-has-rtscts", NULL) ||
2217 of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2218 sport->have_rtscts = 1;
2219
2220 if (of_get_property(np, "fsl,dte-mode", NULL))
2221 sport->dte_mode = 1;
2222
2223 if (of_get_property(np, "rts-gpios", NULL))
2224 sport->have_rtsgpio = 1;
2225
2226 if (of_get_property(np, "fsl,inverted-tx", NULL))
2227 sport->inverted_tx = 1;
2228
2229 if (of_get_property(np, "fsl,inverted-rx", NULL))
2230 sport->inverted_rx = 1;
2231
2232 return 0;
2233}
2234#else
2235static inline int imx_uart_probe_dt(struct imx_port *sport,
2236 struct platform_device *pdev)
2237{
2238 return 1;
2239}
2240#endif
2241
2242static void imx_uart_probe_pdata(struct imx_port *sport,
2243 struct platform_device *pdev)
2244{
2245 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2246
2247 sport->port.line = pdev->id;
2248 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
2249
2250 if (!pdata)
2251 return;
2252
2253 if (pdata->flags & IMXUART_HAVE_RTSCTS)
2254 sport->have_rtscts = 1;
2255}
2256
2257static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t)
2258{
2259 struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx);
2260 unsigned long flags;
2261
2262 spin_lock_irqsave(&sport->port.lock, flags);
2263 if (sport->tx_state == WAIT_AFTER_RTS)
2264 imx_uart_start_tx(&sport->port);
2265 spin_unlock_irqrestore(&sport->port.lock, flags);
2266
2267 return HRTIMER_NORESTART;
2268}
2269
2270static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
2271{
2272 struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx);
2273 unsigned long flags;
2274
2275 spin_lock_irqsave(&sport->port.lock, flags);
2276 if (sport->tx_state == WAIT_AFTER_SEND)
2277 imx_uart_stop_tx(&sport->port);
2278 spin_unlock_irqrestore(&sport->port.lock, flags);
2279
2280 return HRTIMER_NORESTART;
2281}
2282
2283static int imx_uart_probe(struct platform_device *pdev)
2284{
2285 struct imx_port *sport;
2286 void __iomem *base;
2287 int ret = 0;
2288 u32 ucr1;
2289 struct resource *res;
2290 int txirq, rxirq, rtsirq;
2291
2292 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2293 if (!sport)
2294 return -ENOMEM;
2295
2296 ret = imx_uart_probe_dt(sport, pdev);
2297 if (ret > 0)
2298 imx_uart_probe_pdata(sport, pdev);
2299 else if (ret < 0)
2300 return ret;
2301
2302 if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
2303 dev_err(&pdev->dev, "serial%d out of range\n",
2304 sport->port.line);
2305 return -EINVAL;
2306 }
2307
2308 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2309 base = devm_ioremap_resource(&pdev->dev, res);
2310 if (IS_ERR(base))
2311 return PTR_ERR(base);
2312
2313 rxirq = platform_get_irq(pdev, 0);
2314 if (rxirq < 0)
2315 return rxirq;
2316 txirq = platform_get_irq_optional(pdev, 1);
2317 rtsirq = platform_get_irq_optional(pdev, 2);
2318
2319 sport->port.dev = &pdev->dev;
2320 sport->port.mapbase = res->start;
2321 sport->port.membase = base;
2322 sport->port.type = PORT_IMX,
2323 sport->port.iotype = UPIO_MEM;
2324 sport->port.irq = rxirq;
2325 sport->port.fifosize = 32;
2326 sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE);
2327 sport->port.ops = &imx_uart_pops;
2328 sport->port.rs485_config = imx_uart_rs485_config;
2329 sport->port.flags = UPF_BOOT_AUTOCONF;
2330 timer_setup(&sport->timer, imx_uart_timeout, 0);
2331
2332 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2333 if (IS_ERR(sport->gpios))
2334 return PTR_ERR(sport->gpios);
2335
2336 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2337 if (IS_ERR(sport->clk_ipg)) {
2338 ret = PTR_ERR(sport->clk_ipg);
2339 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2340 return ret;
2341 }
2342
2343 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2344 if (IS_ERR(sport->clk_per)) {
2345 ret = PTR_ERR(sport->clk_per);
2346 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2347 return ret;
2348 }
2349
2350 sport->port.uartclk = clk_get_rate(sport->clk_per);
2351
2352 /* For register access, we only need to enable the ipg clock. */
2353 ret = clk_prepare_enable(sport->clk_ipg);
2354 if (ret) {
2355 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2356 return ret;
2357 }
2358
2359 /* initialize shadow register values */
2360 sport->ucr1 = readl(sport->port.membase + UCR1);
2361 sport->ucr2 = readl(sport->port.membase + UCR2);
2362 sport->ucr3 = readl(sport->port.membase + UCR3);
2363 sport->ucr4 = readl(sport->port.membase + UCR4);
2364 sport->ufcr = readl(sport->port.membase + UFCR);
2365
2366 ret = uart_get_rs485_mode(&sport->port);
2367 if (ret) {
2368 clk_disable_unprepare(sport->clk_ipg);
2369 return ret;
2370 }
2371
2372 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2373 (!sport->have_rtscts && !sport->have_rtsgpio))
2374 dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
2375
2376 /*
2377 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
2378 * signal cannot be set low during transmission in case the
2379 * receiver is off (limitation of the i.MX UART IP).
2380 */
2381 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2382 sport->have_rtscts && !sport->have_rtsgpio &&
2383 (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
2384 !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
2385 dev_err(&pdev->dev,
2386 "low-active RTS not possible when receiver is off, enabling receiver\n");
2387
2388 imx_uart_rs485_config(&sport->port, &sport->port.rs485);
2389
2390 /* Disable interrupts before requesting them */
2391 ucr1 = imx_uart_readl(sport, UCR1);
2392 ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2393 UCR1_TRDYEN | UCR1_RTSDEN);
2394 imx_uart_writel(sport, ucr1, UCR1);
2395
2396 if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
2397 /*
2398 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2399 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2400 * and DCD (when they are outputs) or enables the respective
2401 * irqs. So set this bit early, i.e. before requesting irqs.
2402 */
2403 u32 ufcr = imx_uart_readl(sport, UFCR);
2404 if (!(ufcr & UFCR_DCEDTE))
2405 imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
2406
2407 /*
2408 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2409 * enabled later because they cannot be cleared
2410 * (confirmed on i.MX25) which makes them unusable.
2411 */
2412 imx_uart_writel(sport,
2413 IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2414 UCR3);
2415
2416 } else {
2417 u32 ucr3 = UCR3_DSR;
2418 u32 ufcr = imx_uart_readl(sport, UFCR);
2419 if (ufcr & UFCR_DCEDTE)
2420 imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
2421
2422 if (!imx_uart_is_imx1(sport))
2423 ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2424 imx_uart_writel(sport, ucr3, UCR3);
2425 }
2426
2427 clk_disable_unprepare(sport->clk_ipg);
2428
2429 hrtimer_init(&sport->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
2430 hrtimer_init(&sport->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
2431 sport->trigger_start_tx.function = imx_trigger_start_tx;
2432 sport->trigger_stop_tx.function = imx_trigger_stop_tx;
2433
2434 /*
2435 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2436 * chips only have one interrupt.
2437 */
2438 if (txirq > 0) {
2439 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
2440 dev_name(&pdev->dev), sport);
2441 if (ret) {
2442 dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2443 ret);
2444 return ret;
2445 }
2446
2447 ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
2448 dev_name(&pdev->dev), sport);
2449 if (ret) {
2450 dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2451 ret);
2452 return ret;
2453 }
2454
2455 ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
2456 dev_name(&pdev->dev), sport);
2457 if (ret) {
2458 dev_err(&pdev->dev, "failed to request rts irq: %d\n",
2459 ret);
2460 return ret;
2461 }
2462 } else {
2463 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
2464 dev_name(&pdev->dev), sport);
2465 if (ret) {
2466 dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2467 return ret;
2468 }
2469 }
2470
2471 imx_uart_ports[sport->port.line] = sport;
2472
2473 platform_set_drvdata(pdev, sport);
2474
2475 return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
2476}
2477
2478static int imx_uart_remove(struct platform_device *pdev)
2479{
2480 struct imx_port *sport = platform_get_drvdata(pdev);
2481
2482 return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
2483}
2484
2485static void imx_uart_restore_context(struct imx_port *sport)
2486{
2487 unsigned long flags;
2488
2489 spin_lock_irqsave(&sport->port.lock, flags);
2490 if (!sport->context_saved) {
2491 spin_unlock_irqrestore(&sport->port.lock, flags);
2492 return;
2493 }
2494
2495 imx_uart_writel(sport, sport->saved_reg[4], UFCR);
2496 imx_uart_writel(sport, sport->saved_reg[5], UESC);
2497 imx_uart_writel(sport, sport->saved_reg[6], UTIM);
2498 imx_uart_writel(sport, sport->saved_reg[7], UBIR);
2499 imx_uart_writel(sport, sport->saved_reg[8], UBMR);
2500 imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
2501 imx_uart_writel(sport, sport->saved_reg[0], UCR1);
2502 imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
2503 imx_uart_writel(sport, sport->saved_reg[2], UCR3);
2504 imx_uart_writel(sport, sport->saved_reg[3], UCR4);
2505 sport->context_saved = false;
2506 spin_unlock_irqrestore(&sport->port.lock, flags);
2507}
2508
2509static void imx_uart_save_context(struct imx_port *sport)
2510{
2511 unsigned long flags;
2512
2513 /* Save necessary regs */
2514 spin_lock_irqsave(&sport->port.lock, flags);
2515 sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
2516 sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
2517 sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
2518 sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
2519 sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
2520 sport->saved_reg[5] = imx_uart_readl(sport, UESC);
2521 sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
2522 sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
2523 sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
2524 sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
2525 sport->context_saved = true;
2526 spin_unlock_irqrestore(&sport->port.lock, flags);
2527}
2528
2529static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
2530{
2531 u32 ucr3;
2532
2533 ucr3 = imx_uart_readl(sport, UCR3);
2534 if (on) {
2535 imx_uart_writel(sport, USR1_AWAKE, USR1);
2536 ucr3 |= UCR3_AWAKEN;
2537 } else {
2538 ucr3 &= ~UCR3_AWAKEN;
2539 }
2540 imx_uart_writel(sport, ucr3, UCR3);
2541
2542 if (sport->have_rtscts) {
2543 u32 ucr1 = imx_uart_readl(sport, UCR1);
2544 if (on)
2545 ucr1 |= UCR1_RTSDEN;
2546 else
2547 ucr1 &= ~UCR1_RTSDEN;
2548 imx_uart_writel(sport, ucr1, UCR1);
2549 }
2550}
2551
2552static int imx_uart_suspend_noirq(struct device *dev)
2553{
2554 struct imx_port *sport = dev_get_drvdata(dev);
2555
2556 imx_uart_save_context(sport);
2557
2558 clk_disable(sport->clk_ipg);
2559
2560 pinctrl_pm_select_sleep_state(dev);
2561
2562 return 0;
2563}
2564
2565static int imx_uart_resume_noirq(struct device *dev)
2566{
2567 struct imx_port *sport = dev_get_drvdata(dev);
2568 int ret;
2569
2570 pinctrl_pm_select_default_state(dev);
2571
2572 ret = clk_enable(sport->clk_ipg);
2573 if (ret)
2574 return ret;
2575
2576 imx_uart_restore_context(sport);
2577
2578 return 0;
2579}
2580
2581static int imx_uart_suspend(struct device *dev)
2582{
2583 struct imx_port *sport = dev_get_drvdata(dev);
2584 int ret;
2585
2586 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2587 disable_irq(sport->port.irq);
2588
2589 ret = clk_prepare_enable(sport->clk_ipg);
2590 if (ret)
2591 return ret;
2592
2593 /* enable wakeup from i.MX UART */
2594 imx_uart_enable_wakeup(sport, true);
2595
2596 return 0;
2597}
2598
2599static int imx_uart_resume(struct device *dev)
2600{
2601 struct imx_port *sport = dev_get_drvdata(dev);
2602
2603 /* disable wakeup from i.MX UART */
2604 imx_uart_enable_wakeup(sport, false);
2605
2606 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2607 enable_irq(sport->port.irq);
2608
2609 clk_disable_unprepare(sport->clk_ipg);
2610
2611 return 0;
2612}
2613
2614static int imx_uart_freeze(struct device *dev)
2615{
2616 struct imx_port *sport = dev_get_drvdata(dev);
2617
2618 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2619
2620 return clk_prepare_enable(sport->clk_ipg);
2621}
2622
2623static int imx_uart_thaw(struct device *dev)
2624{
2625 struct imx_port *sport = dev_get_drvdata(dev);
2626
2627 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2628
2629 clk_disable_unprepare(sport->clk_ipg);
2630
2631 return 0;
2632}
2633
2634static const struct dev_pm_ops imx_uart_pm_ops = {
2635 .suspend_noirq = imx_uart_suspend_noirq,
2636 .resume_noirq = imx_uart_resume_noirq,
2637 .freeze_noirq = imx_uart_suspend_noirq,
2638 .restore_noirq = imx_uart_resume_noirq,
2639 .suspend = imx_uart_suspend,
2640 .resume = imx_uart_resume,
2641 .freeze = imx_uart_freeze,
2642 .thaw = imx_uart_thaw,
2643 .restore = imx_uart_thaw,
2644};
2645
2646static struct platform_driver imx_uart_platform_driver = {
2647 .probe = imx_uart_probe,
2648 .remove = imx_uart_remove,
2649
2650 .id_table = imx_uart_devtype,
2651 .driver = {
2652 .name = "imx-uart",
2653 .of_match_table = imx_uart_dt_ids,
2654 .pm = &imx_uart_pm_ops,
2655 },
2656};
2657
2658static int __init imx_uart_init(void)
2659{
2660 int ret = uart_register_driver(&imx_uart_uart_driver);
2661
2662 if (ret)
2663 return ret;
2664
2665 ret = platform_driver_register(&imx_uart_platform_driver);
2666 if (ret != 0)
2667 uart_unregister_driver(&imx_uart_uart_driver);
2668
2669 return ret;
2670}
2671
2672static void __exit imx_uart_exit(void)
2673{
2674 platform_driver_unregister(&imx_uart_platform_driver);
2675 uart_unregister_driver(&imx_uart_uart_driver);
2676}
2677
2678module_init(imx_uart_init);
2679module_exit(imx_uart_exit);
2680
2681MODULE_AUTHOR("Sascha Hauer");
2682MODULE_DESCRIPTION("IMX generic serial port driver");
2683MODULE_LICENSE("GPL");
2684MODULE_ALIAS("platform:imx-uart");