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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Cadence UART driver (found in Xilinx Zynq)
4 *
5 * 2011 - 2014 (C) Xilinx Inc.
6 *
7 * This driver has originally been pushed by Xilinx using a Zynq-branding. This
8 * still shows in the naming of this file, the kconfig symbols and some symbols
9 * in the code.
10 */
11
12#if defined(CONFIG_SERIAL_XILINX_PS_UART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
13#define SUPPORT_SYSRQ
14#endif
15
16#include <linux/platform_device.h>
17#include <linux/serial.h>
18#include <linux/console.h>
19#include <linux/serial_core.h>
20#include <linux/slab.h>
21#include <linux/tty.h>
22#include <linux/tty_flip.h>
23#include <linux/clk.h>
24#include <linux/irq.h>
25#include <linux/io.h>
26#include <linux/of.h>
27#include <linux/module.h>
28#include <linux/pm_runtime.h>
29#include <linux/iopoll.h>
30
31#define CDNS_UART_TTY_NAME "ttyPS"
32#define CDNS_UART_NAME "xuartps"
33#define CDNS_UART_FIFO_SIZE 64 /* FIFO size */
34#define CDNS_UART_REGISTER_SPACE 0x1000
35#define TX_TIMEOUT 500000
36
37/* Rx Trigger level */
38static int rx_trigger_level = 56;
39static int uartps_major;
40module_param(rx_trigger_level, uint, 0444);
41MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");
42
43/* Rx Timeout */
44static int rx_timeout = 10;
45module_param(rx_timeout, uint, 0444);
46MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
47
48/* Register offsets for the UART. */
49#define CDNS_UART_CR 0x00 /* Control Register */
50#define CDNS_UART_MR 0x04 /* Mode Register */
51#define CDNS_UART_IER 0x08 /* Interrupt Enable */
52#define CDNS_UART_IDR 0x0C /* Interrupt Disable */
53#define CDNS_UART_IMR 0x10 /* Interrupt Mask */
54#define CDNS_UART_ISR 0x14 /* Interrupt Status */
55#define CDNS_UART_BAUDGEN 0x18 /* Baud Rate Generator */
56#define CDNS_UART_RXTOUT 0x1C /* RX Timeout */
57#define CDNS_UART_RXWM 0x20 /* RX FIFO Trigger Level */
58#define CDNS_UART_MODEMCR 0x24 /* Modem Control */
59#define CDNS_UART_MODEMSR 0x28 /* Modem Status */
60#define CDNS_UART_SR 0x2C /* Channel Status */
61#define CDNS_UART_FIFO 0x30 /* FIFO */
62#define CDNS_UART_BAUDDIV 0x34 /* Baud Rate Divider */
63#define CDNS_UART_FLOWDEL 0x38 /* Flow Delay */
64#define CDNS_UART_IRRX_PWIDTH 0x3C /* IR Min Received Pulse Width */
65#define CDNS_UART_IRTX_PWIDTH 0x40 /* IR Transmitted pulse Width */
66#define CDNS_UART_TXWM 0x44 /* TX FIFO Trigger Level */
67#define CDNS_UART_RXBS 0x48 /* RX FIFO byte status register */
68
69/* Control Register Bit Definitions */
70#define CDNS_UART_CR_STOPBRK 0x00000100 /* Stop TX break */
71#define CDNS_UART_CR_STARTBRK 0x00000080 /* Set TX break */
72#define CDNS_UART_CR_TX_DIS 0x00000020 /* TX disabled. */
73#define CDNS_UART_CR_TX_EN 0x00000010 /* TX enabled */
74#define CDNS_UART_CR_RX_DIS 0x00000008 /* RX disabled. */
75#define CDNS_UART_CR_RX_EN 0x00000004 /* RX enabled */
76#define CDNS_UART_CR_TXRST 0x00000002 /* TX logic reset */
77#define CDNS_UART_CR_RXRST 0x00000001 /* RX logic reset */
78#define CDNS_UART_CR_RST_TO 0x00000040 /* Restart Timeout Counter */
79#define CDNS_UART_RXBS_PARITY 0x00000001 /* Parity error status */
80#define CDNS_UART_RXBS_FRAMING 0x00000002 /* Framing error status */
81#define CDNS_UART_RXBS_BRK 0x00000004 /* Overrun error status */
82
83/*
84 * Mode Register:
85 * The mode register (MR) defines the mode of transfer as well as the data
86 * format. If this register is modified during transmission or reception,
87 * data validity cannot be guaranteed.
88 */
89#define CDNS_UART_MR_CLKSEL 0x00000001 /* Pre-scalar selection */
90#define CDNS_UART_MR_CHMODE_L_LOOP 0x00000200 /* Local loop back mode */
91#define CDNS_UART_MR_CHMODE_NORM 0x00000000 /* Normal mode */
92#define CDNS_UART_MR_CHMODE_MASK 0x00000300 /* Mask for mode bits */
93
94#define CDNS_UART_MR_STOPMODE_2_BIT 0x00000080 /* 2 stop bits */
95#define CDNS_UART_MR_STOPMODE_1_BIT 0x00000000 /* 1 stop bit */
96
97#define CDNS_UART_MR_PARITY_NONE 0x00000020 /* No parity mode */
98#define CDNS_UART_MR_PARITY_MARK 0x00000018 /* Mark parity mode */
99#define CDNS_UART_MR_PARITY_SPACE 0x00000010 /* Space parity mode */
100#define CDNS_UART_MR_PARITY_ODD 0x00000008 /* Odd parity mode */
101#define CDNS_UART_MR_PARITY_EVEN 0x00000000 /* Even parity mode */
102
103#define CDNS_UART_MR_CHARLEN_6_BIT 0x00000006 /* 6 bits data */
104#define CDNS_UART_MR_CHARLEN_7_BIT 0x00000004 /* 7 bits data */
105#define CDNS_UART_MR_CHARLEN_8_BIT 0x00000000 /* 8 bits data */
106
107/*
108 * Interrupt Registers:
109 * Interrupt control logic uses the interrupt enable register (IER) and the
110 * interrupt disable register (IDR) to set the value of the bits in the
111 * interrupt mask register (IMR). The IMR determines whether to pass an
112 * interrupt to the interrupt status register (ISR).
113 * Writing a 1 to IER Enables an interrupt, writing a 1 to IDR disables an
114 * interrupt. IMR and ISR are read only, and IER and IDR are write only.
115 * Reading either IER or IDR returns 0x00.
116 * All four registers have the same bit definitions.
117 */
118#define CDNS_UART_IXR_TOUT 0x00000100 /* RX Timeout error interrupt */
119#define CDNS_UART_IXR_PARITY 0x00000080 /* Parity error interrupt */
120#define CDNS_UART_IXR_FRAMING 0x00000040 /* Framing error interrupt */
121#define CDNS_UART_IXR_OVERRUN 0x00000020 /* Overrun error interrupt */
122#define CDNS_UART_IXR_TXFULL 0x00000010 /* TX FIFO Full interrupt */
123#define CDNS_UART_IXR_TXEMPTY 0x00000008 /* TX FIFO empty interrupt */
124#define CDNS_UART_ISR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt */
125#define CDNS_UART_IXR_RXTRIG 0x00000001 /* RX FIFO trigger interrupt */
126#define CDNS_UART_IXR_RXFULL 0x00000004 /* RX FIFO full interrupt. */
127#define CDNS_UART_IXR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt. */
128#define CDNS_UART_IXR_RXMASK 0x000021e7 /* Valid RX bit mask */
129
130 /*
131 * Do not enable parity error interrupt for the following
132 * reason: When parity error interrupt is enabled, each Rx
133 * parity error always results in 2 events. The first one
134 * being parity error interrupt and the second one with a
135 * proper Rx interrupt with the incoming data. Disabling
136 * parity error interrupt ensures better handling of parity
137 * error events. With this change, for a parity error case, we
138 * get a Rx interrupt with parity error set in ISR register
139 * and we still handle parity errors in the desired way.
140 */
141
142#define CDNS_UART_RX_IRQS (CDNS_UART_IXR_FRAMING | \
143 CDNS_UART_IXR_OVERRUN | \
144 CDNS_UART_IXR_RXTRIG | \
145 CDNS_UART_IXR_TOUT)
146
147/* Goes in read_status_mask for break detection as the HW doesn't do it*/
148#define CDNS_UART_IXR_BRK 0x00002000
149
150#define CDNS_UART_RXBS_SUPPORT BIT(1)
151/*
152 * Modem Control register:
153 * The read/write Modem Control register controls the interface with the modem
154 * or data set, or a peripheral device emulating a modem.
155 */
156#define CDNS_UART_MODEMCR_FCM 0x00000020 /* Automatic flow control mode */
157#define CDNS_UART_MODEMCR_RTS 0x00000002 /* Request to send output control */
158#define CDNS_UART_MODEMCR_DTR 0x00000001 /* Data Terminal Ready */
159
160/*
161 * Channel Status Register:
162 * The channel status register (CSR) is provided to enable the control logic
163 * to monitor the status of bits in the channel interrupt status register,
164 * even if these are masked out by the interrupt mask register.
165 */
166#define CDNS_UART_SR_RXEMPTY 0x00000002 /* RX FIFO empty */
167#define CDNS_UART_SR_TXEMPTY 0x00000008 /* TX FIFO empty */
168#define CDNS_UART_SR_TXFULL 0x00000010 /* TX FIFO full */
169#define CDNS_UART_SR_RXTRIG 0x00000001 /* Rx Trigger */
170#define CDNS_UART_SR_TACTIVE 0x00000800 /* TX state machine active */
171
172/* baud dividers min/max values */
173#define CDNS_UART_BDIV_MIN 4
174#define CDNS_UART_BDIV_MAX 255
175#define CDNS_UART_CD_MAX 65535
176#define UART_AUTOSUSPEND_TIMEOUT 3000
177
178/**
179 * struct cdns_uart - device data
180 * @port: Pointer to the UART port
181 * @uartclk: Reference clock
182 * @pclk: APB clock
183 * @cdns_uart_driver: Pointer to UART driver
184 * @baud: Current baud rate
185 * @id: Port ID
186 * @clk_rate_change_nb: Notifier block for clock changes
187 * @quirks: Flags for RXBS support.
188 */
189struct cdns_uart {
190 struct uart_port *port;
191 struct clk *uartclk;
192 struct clk *pclk;
193 struct uart_driver *cdns_uart_driver;
194 unsigned int baud;
195 int id;
196 struct notifier_block clk_rate_change_nb;
197 u32 quirks;
198 bool cts_override;
199};
200struct cdns_platform_data {
201 u32 quirks;
202};
203#define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \
204 clk_rate_change_nb)
205
206/**
207 * cdns_uart_handle_rx - Handle the received bytes along with Rx errors.
208 * @dev_id: Id of the UART port
209 * @isrstatus: The interrupt status register value as read
210 * Return: None
211 */
212static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus)
213{
214 struct uart_port *port = (struct uart_port *)dev_id;
215 struct cdns_uart *cdns_uart = port->private_data;
216 unsigned int data;
217 unsigned int rxbs_status = 0;
218 unsigned int status_mask;
219 unsigned int framerrprocessed = 0;
220 char status = TTY_NORMAL;
221 bool is_rxbs_support;
222
223 is_rxbs_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;
224
225 while ((readl(port->membase + CDNS_UART_SR) &
226 CDNS_UART_SR_RXEMPTY) != CDNS_UART_SR_RXEMPTY) {
227 if (is_rxbs_support)
228 rxbs_status = readl(port->membase + CDNS_UART_RXBS);
229 data = readl(port->membase + CDNS_UART_FIFO);
230 port->icount.rx++;
231 /*
232 * There is no hardware break detection in Zynq, so we interpret
233 * framing error with all-zeros data as a break sequence.
234 * Most of the time, there's another non-zero byte at the
235 * end of the sequence.
236 */
237 if (!is_rxbs_support && (isrstatus & CDNS_UART_IXR_FRAMING)) {
238 if (!data) {
239 port->read_status_mask |= CDNS_UART_IXR_BRK;
240 framerrprocessed = 1;
241 continue;
242 }
243 }
244 if (is_rxbs_support && (rxbs_status & CDNS_UART_RXBS_BRK)) {
245 port->icount.brk++;
246 status = TTY_BREAK;
247 if (uart_handle_break(port))
248 continue;
249 }
250
251 isrstatus &= port->read_status_mask;
252 isrstatus &= ~port->ignore_status_mask;
253 status_mask = port->read_status_mask;
254 status_mask &= ~port->ignore_status_mask;
255
256 if (data &&
257 (port->read_status_mask & CDNS_UART_IXR_BRK)) {
258 port->read_status_mask &= ~CDNS_UART_IXR_BRK;
259 port->icount.brk++;
260 if (uart_handle_break(port))
261 continue;
262 }
263
264 if (uart_handle_sysrq_char(port, data))
265 continue;
266
267 if (is_rxbs_support) {
268 if ((rxbs_status & CDNS_UART_RXBS_PARITY)
269 && (status_mask & CDNS_UART_IXR_PARITY)) {
270 port->icount.parity++;
271 status = TTY_PARITY;
272 }
273 if ((rxbs_status & CDNS_UART_RXBS_FRAMING)
274 && (status_mask & CDNS_UART_IXR_PARITY)) {
275 port->icount.frame++;
276 status = TTY_FRAME;
277 }
278 } else {
279 if (isrstatus & CDNS_UART_IXR_PARITY) {
280 port->icount.parity++;
281 status = TTY_PARITY;
282 }
283 if ((isrstatus & CDNS_UART_IXR_FRAMING) &&
284 !framerrprocessed) {
285 port->icount.frame++;
286 status = TTY_FRAME;
287 }
288 }
289 if (isrstatus & CDNS_UART_IXR_OVERRUN) {
290 port->icount.overrun++;
291 tty_insert_flip_char(&port->state->port, 0,
292 TTY_OVERRUN);
293 }
294 tty_insert_flip_char(&port->state->port, data, status);
295 isrstatus = 0;
296 }
297 spin_unlock(&port->lock);
298 tty_flip_buffer_push(&port->state->port);
299 spin_lock(&port->lock);
300}
301
302/**
303 * cdns_uart_handle_tx - Handle the bytes to be Txed.
304 * @dev_id: Id of the UART port
305 * Return: None
306 */
307static void cdns_uart_handle_tx(void *dev_id)
308{
309 struct uart_port *port = (struct uart_port *)dev_id;
310 unsigned int numbytes;
311
312 if (uart_circ_empty(&port->state->xmit)) {
313 writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR);
314 } else {
315 numbytes = port->fifosize;
316 while (numbytes && !uart_circ_empty(&port->state->xmit) &&
317 !(readl(port->membase + CDNS_UART_SR) &
318 CDNS_UART_SR_TXFULL)) {
319 /*
320 * Get the data from the UART circular buffer
321 * and write it to the cdns_uart's TX_FIFO
322 * register.
323 */
324 writel(
325 port->state->xmit.buf[port->state->xmit.tail],
326 port->membase + CDNS_UART_FIFO);
327
328 port->icount.tx++;
329
330 /*
331 * Adjust the tail of the UART buffer and wrap
332 * the buffer if it reaches limit.
333 */
334 port->state->xmit.tail =
335 (port->state->xmit.tail + 1) &
336 (UART_XMIT_SIZE - 1);
337
338 numbytes--;
339 }
340
341 if (uart_circ_chars_pending(
342 &port->state->xmit) < WAKEUP_CHARS)
343 uart_write_wakeup(port);
344 }
345}
346
347/**
348 * cdns_uart_isr - Interrupt handler
349 * @irq: Irq number
350 * @dev_id: Id of the port
351 *
352 * Return: IRQHANDLED
353 */
354static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
355{
356 struct uart_port *port = (struct uart_port *)dev_id;
357 unsigned int isrstatus;
358
359 spin_lock(&port->lock);
360
361 /* Read the interrupt status register to determine which
362 * interrupt(s) is/are active and clear them.
363 */
364 isrstatus = readl(port->membase + CDNS_UART_ISR);
365 writel(isrstatus, port->membase + CDNS_UART_ISR);
366
367 if (isrstatus & CDNS_UART_IXR_TXEMPTY) {
368 cdns_uart_handle_tx(dev_id);
369 isrstatus &= ~CDNS_UART_IXR_TXEMPTY;
370 }
371
372 /*
373 * Skip RX processing if RX is disabled as RXEMPTY will never be set
374 * as read bytes will not be removed from the FIFO.
375 */
376 if (isrstatus & CDNS_UART_IXR_RXMASK &&
377 !(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_RX_DIS))
378 cdns_uart_handle_rx(dev_id, isrstatus);
379
380 spin_unlock(&port->lock);
381 return IRQ_HANDLED;
382}
383
384/**
385 * cdns_uart_calc_baud_divs - Calculate baud rate divisors
386 * @clk: UART module input clock
387 * @baud: Desired baud rate
388 * @rbdiv: BDIV value (return value)
389 * @rcd: CD value (return value)
390 * @div8: Value for clk_sel bit in mod (return value)
391 * Return: baud rate, requested baud when possible, or actual baud when there
392 * was too much error, zero if no valid divisors are found.
393 *
394 * Formula to obtain baud rate is
395 * baud_tx/rx rate = clk/CD * (BDIV + 1)
396 * input_clk = (Uart User Defined Clock or Apb Clock)
397 * depends on UCLKEN in MR Reg
398 * clk = input_clk or input_clk/8;
399 * depends on CLKS in MR reg
400 * CD and BDIV depends on values in
401 * baud rate generate register
402 * baud rate clock divisor register
403 */
404static unsigned int cdns_uart_calc_baud_divs(unsigned int clk,
405 unsigned int baud, u32 *rbdiv, u32 *rcd, int *div8)
406{
407 u32 cd, bdiv;
408 unsigned int calc_baud;
409 unsigned int bestbaud = 0;
410 unsigned int bauderror;
411 unsigned int besterror = ~0;
412
413 if (baud < clk / ((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX)) {
414 *div8 = 1;
415 clk /= 8;
416 } else {
417 *div8 = 0;
418 }
419
420 for (bdiv = CDNS_UART_BDIV_MIN; bdiv <= CDNS_UART_BDIV_MAX; bdiv++) {
421 cd = DIV_ROUND_CLOSEST(clk, baud * (bdiv + 1));
422 if (cd < 1 || cd > CDNS_UART_CD_MAX)
423 continue;
424
425 calc_baud = clk / (cd * (bdiv + 1));
426
427 if (baud > calc_baud)
428 bauderror = baud - calc_baud;
429 else
430 bauderror = calc_baud - baud;
431
432 if (besterror > bauderror) {
433 *rbdiv = bdiv;
434 *rcd = cd;
435 bestbaud = calc_baud;
436 besterror = bauderror;
437 }
438 }
439 /* use the values when percent error is acceptable */
440 if (((besterror * 100) / baud) < 3)
441 bestbaud = baud;
442
443 return bestbaud;
444}
445
446/**
447 * cdns_uart_set_baud_rate - Calculate and set the baud rate
448 * @port: Handle to the uart port structure
449 * @baud: Baud rate to set
450 * Return: baud rate, requested baud when possible, or actual baud when there
451 * was too much error, zero if no valid divisors are found.
452 */
453static unsigned int cdns_uart_set_baud_rate(struct uart_port *port,
454 unsigned int baud)
455{
456 unsigned int calc_baud;
457 u32 cd = 0, bdiv = 0;
458 u32 mreg;
459 int div8;
460 struct cdns_uart *cdns_uart = port->private_data;
461
462 calc_baud = cdns_uart_calc_baud_divs(port->uartclk, baud, &bdiv, &cd,
463 &div8);
464
465 /* Write new divisors to hardware */
466 mreg = readl(port->membase + CDNS_UART_MR);
467 if (div8)
468 mreg |= CDNS_UART_MR_CLKSEL;
469 else
470 mreg &= ~CDNS_UART_MR_CLKSEL;
471 writel(mreg, port->membase + CDNS_UART_MR);
472 writel(cd, port->membase + CDNS_UART_BAUDGEN);
473 writel(bdiv, port->membase + CDNS_UART_BAUDDIV);
474 cdns_uart->baud = baud;
475
476 return calc_baud;
477}
478
479#ifdef CONFIG_COMMON_CLK
480/**
481 * cdns_uart_clk_notitifer_cb - Clock notifier callback
482 * @nb: Notifier block
483 * @event: Notify event
484 * @data: Notifier data
485 * Return: NOTIFY_OK or NOTIFY_DONE on success, NOTIFY_BAD on error.
486 */
487static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
488 unsigned long event, void *data)
489{
490 u32 ctrl_reg;
491 struct uart_port *port;
492 int locked = 0;
493 struct clk_notifier_data *ndata = data;
494 unsigned long flags = 0;
495 struct cdns_uart *cdns_uart = to_cdns_uart(nb);
496
497 port = cdns_uart->port;
498 if (port->suspended)
499 return NOTIFY_OK;
500
501 switch (event) {
502 case PRE_RATE_CHANGE:
503 {
504 u32 bdiv, cd;
505 int div8;
506
507 /*
508 * Find out if current baud-rate can be achieved with new clock
509 * frequency.
510 */
511 if (!cdns_uart_calc_baud_divs(ndata->new_rate, cdns_uart->baud,
512 &bdiv, &cd, &div8)) {
513 dev_warn(port->dev, "clock rate change rejected\n");
514 return NOTIFY_BAD;
515 }
516
517 spin_lock_irqsave(&cdns_uart->port->lock, flags);
518
519 /* Disable the TX and RX to set baud rate */
520 ctrl_reg = readl(port->membase + CDNS_UART_CR);
521 ctrl_reg |= CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS;
522 writel(ctrl_reg, port->membase + CDNS_UART_CR);
523
524 spin_unlock_irqrestore(&cdns_uart->port->lock, flags);
525
526 return NOTIFY_OK;
527 }
528 case POST_RATE_CHANGE:
529 /*
530 * Set clk dividers to generate correct baud with new clock
531 * frequency.
532 */
533
534 spin_lock_irqsave(&cdns_uart->port->lock, flags);
535
536 locked = 1;
537 port->uartclk = ndata->new_rate;
538
539 cdns_uart->baud = cdns_uart_set_baud_rate(cdns_uart->port,
540 cdns_uart->baud);
541 /* fall through */
542 case ABORT_RATE_CHANGE:
543 if (!locked)
544 spin_lock_irqsave(&cdns_uart->port->lock, flags);
545
546 /* Set TX/RX Reset */
547 ctrl_reg = readl(port->membase + CDNS_UART_CR);
548 ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
549 writel(ctrl_reg, port->membase + CDNS_UART_CR);
550
551 while (readl(port->membase + CDNS_UART_CR) &
552 (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
553 cpu_relax();
554
555 /*
556 * Clear the RX disable and TX disable bits and then set the TX
557 * enable bit and RX enable bit to enable the transmitter and
558 * receiver.
559 */
560 writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
561 ctrl_reg = readl(port->membase + CDNS_UART_CR);
562 ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
563 ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
564 writel(ctrl_reg, port->membase + CDNS_UART_CR);
565
566 spin_unlock_irqrestore(&cdns_uart->port->lock, flags);
567
568 return NOTIFY_OK;
569 default:
570 return NOTIFY_DONE;
571 }
572}
573#endif
574
575/**
576 * cdns_uart_start_tx - Start transmitting bytes
577 * @port: Handle to the uart port structure
578 */
579static void cdns_uart_start_tx(struct uart_port *port)
580{
581 unsigned int status;
582
583 if (uart_tx_stopped(port))
584 return;
585
586 /*
587 * Set the TX enable bit and clear the TX disable bit to enable the
588 * transmitter.
589 */
590 status = readl(port->membase + CDNS_UART_CR);
591 status &= ~CDNS_UART_CR_TX_DIS;
592 status |= CDNS_UART_CR_TX_EN;
593 writel(status, port->membase + CDNS_UART_CR);
594
595 if (uart_circ_empty(&port->state->xmit))
596 return;
597
598 cdns_uart_handle_tx(port);
599
600 writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);
601 /* Enable the TX Empty interrupt */
602 writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IER);
603}
604
605/**
606 * cdns_uart_stop_tx - Stop TX
607 * @port: Handle to the uart port structure
608 */
609static void cdns_uart_stop_tx(struct uart_port *port)
610{
611 unsigned int regval;
612
613 regval = readl(port->membase + CDNS_UART_CR);
614 regval |= CDNS_UART_CR_TX_DIS;
615 /* Disable the transmitter */
616 writel(regval, port->membase + CDNS_UART_CR);
617}
618
619/**
620 * cdns_uart_stop_rx - Stop RX
621 * @port: Handle to the uart port structure
622 */
623static void cdns_uart_stop_rx(struct uart_port *port)
624{
625 unsigned int regval;
626
627 /* Disable RX IRQs */
628 writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IDR);
629
630 /* Disable the receiver */
631 regval = readl(port->membase + CDNS_UART_CR);
632 regval |= CDNS_UART_CR_RX_DIS;
633 writel(regval, port->membase + CDNS_UART_CR);
634}
635
636/**
637 * cdns_uart_tx_empty - Check whether TX is empty
638 * @port: Handle to the uart port structure
639 *
640 * Return: TIOCSER_TEMT on success, 0 otherwise
641 */
642static unsigned int cdns_uart_tx_empty(struct uart_port *port)
643{
644 unsigned int status;
645
646 status = readl(port->membase + CDNS_UART_SR) &
647 CDNS_UART_SR_TXEMPTY;
648 return status ? TIOCSER_TEMT : 0;
649}
650
651/**
652 * cdns_uart_break_ctl - Based on the input ctl we have to start or stop
653 * transmitting char breaks
654 * @port: Handle to the uart port structure
655 * @ctl: Value based on which start or stop decision is taken
656 */
657static void cdns_uart_break_ctl(struct uart_port *port, int ctl)
658{
659 unsigned int status;
660 unsigned long flags;
661
662 spin_lock_irqsave(&port->lock, flags);
663
664 status = readl(port->membase + CDNS_UART_CR);
665
666 if (ctl == -1)
667 writel(CDNS_UART_CR_STARTBRK | status,
668 port->membase + CDNS_UART_CR);
669 else {
670 if ((status & CDNS_UART_CR_STOPBRK) == 0)
671 writel(CDNS_UART_CR_STOPBRK | status,
672 port->membase + CDNS_UART_CR);
673 }
674 spin_unlock_irqrestore(&port->lock, flags);
675}
676
677/**
678 * cdns_uart_set_termios - termios operations, handling data length, parity,
679 * stop bits, flow control, baud rate
680 * @port: Handle to the uart port structure
681 * @termios: Handle to the input termios structure
682 * @old: Values of the previously saved termios structure
683 */
684static void cdns_uart_set_termios(struct uart_port *port,
685 struct ktermios *termios, struct ktermios *old)
686{
687 unsigned int cval = 0;
688 unsigned int baud, minbaud, maxbaud;
689 unsigned long flags;
690 unsigned int ctrl_reg, mode_reg, val;
691 int err;
692
693 /* Wait for the transmit FIFO to empty before making changes */
694 if (!(readl(port->membase + CDNS_UART_CR) &
695 CDNS_UART_CR_TX_DIS)) {
696 err = readl_poll_timeout(port->membase + CDNS_UART_SR,
697 val, (val & CDNS_UART_SR_TXEMPTY),
698 1000, TX_TIMEOUT);
699 if (err) {
700 dev_err(port->dev, "timed out waiting for tx empty");
701 return;
702 }
703 }
704 spin_lock_irqsave(&port->lock, flags);
705
706 /* Disable the TX and RX to set baud rate */
707 ctrl_reg = readl(port->membase + CDNS_UART_CR);
708 ctrl_reg |= CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS;
709 writel(ctrl_reg, port->membase + CDNS_UART_CR);
710
711 /*
712 * Min baud rate = 6bps and Max Baud Rate is 10Mbps for 100Mhz clk
713 * min and max baud should be calculated here based on port->uartclk.
714 * this way we get a valid baud and can safely call set_baud()
715 */
716 minbaud = port->uartclk /
717 ((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX * 8);
718 maxbaud = port->uartclk / (CDNS_UART_BDIV_MIN + 1);
719 baud = uart_get_baud_rate(port, termios, old, minbaud, maxbaud);
720 baud = cdns_uart_set_baud_rate(port, baud);
721 if (tty_termios_baud_rate(termios))
722 tty_termios_encode_baud_rate(termios, baud, baud);
723
724 /* Update the per-port timeout. */
725 uart_update_timeout(port, termios->c_cflag, baud);
726
727 /* Set TX/RX Reset */
728 ctrl_reg = readl(port->membase + CDNS_UART_CR);
729 ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
730 writel(ctrl_reg, port->membase + CDNS_UART_CR);
731
732 while (readl(port->membase + CDNS_UART_CR) &
733 (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
734 cpu_relax();
735
736 /*
737 * Clear the RX disable and TX disable bits and then set the TX enable
738 * bit and RX enable bit to enable the transmitter and receiver.
739 */
740 ctrl_reg = readl(port->membase + CDNS_UART_CR);
741 ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
742 ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
743 writel(ctrl_reg, port->membase + CDNS_UART_CR);
744
745 writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
746
747 port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |
748 CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_TOUT;
749 port->ignore_status_mask = 0;
750
751 if (termios->c_iflag & INPCK)
752 port->read_status_mask |= CDNS_UART_IXR_PARITY |
753 CDNS_UART_IXR_FRAMING;
754
755 if (termios->c_iflag & IGNPAR)
756 port->ignore_status_mask |= CDNS_UART_IXR_PARITY |
757 CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN;
758
759 /* ignore all characters if CREAD is not set */
760 if ((termios->c_cflag & CREAD) == 0)
761 port->ignore_status_mask |= CDNS_UART_IXR_RXTRIG |
762 CDNS_UART_IXR_TOUT | CDNS_UART_IXR_PARITY |
763 CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN;
764
765 mode_reg = readl(port->membase + CDNS_UART_MR);
766
767 /* Handling Data Size */
768 switch (termios->c_cflag & CSIZE) {
769 case CS6:
770 cval |= CDNS_UART_MR_CHARLEN_6_BIT;
771 break;
772 case CS7:
773 cval |= CDNS_UART_MR_CHARLEN_7_BIT;
774 break;
775 default:
776 case CS8:
777 cval |= CDNS_UART_MR_CHARLEN_8_BIT;
778 termios->c_cflag &= ~CSIZE;
779 termios->c_cflag |= CS8;
780 break;
781 }
782
783 /* Handling Parity and Stop Bits length */
784 if (termios->c_cflag & CSTOPB)
785 cval |= CDNS_UART_MR_STOPMODE_2_BIT; /* 2 STOP bits */
786 else
787 cval |= CDNS_UART_MR_STOPMODE_1_BIT; /* 1 STOP bit */
788
789 if (termios->c_cflag & PARENB) {
790 /* Mark or Space parity */
791 if (termios->c_cflag & CMSPAR) {
792 if (termios->c_cflag & PARODD)
793 cval |= CDNS_UART_MR_PARITY_MARK;
794 else
795 cval |= CDNS_UART_MR_PARITY_SPACE;
796 } else {
797 if (termios->c_cflag & PARODD)
798 cval |= CDNS_UART_MR_PARITY_ODD;
799 else
800 cval |= CDNS_UART_MR_PARITY_EVEN;
801 }
802 } else {
803 cval |= CDNS_UART_MR_PARITY_NONE;
804 }
805 cval |= mode_reg & 1;
806 writel(cval, port->membase + CDNS_UART_MR);
807
808 spin_unlock_irqrestore(&port->lock, flags);
809}
810
811/**
812 * cdns_uart_startup - Called when an application opens a cdns_uart port
813 * @port: Handle to the uart port structure
814 *
815 * Return: 0 on success, negative errno otherwise
816 */
817static int cdns_uart_startup(struct uart_port *port)
818{
819 struct cdns_uart *cdns_uart = port->private_data;
820 bool is_brk_support;
821 int ret;
822 unsigned long flags;
823 unsigned int status = 0;
824
825 is_brk_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;
826
827 spin_lock_irqsave(&port->lock, flags);
828
829 /* Disable the TX and RX */
830 writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
831 port->membase + CDNS_UART_CR);
832
833 /* Set the Control Register with TX/RX Enable, TX/RX Reset,
834 * no break chars.
835 */
836 writel(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST,
837 port->membase + CDNS_UART_CR);
838
839 while (readl(port->membase + CDNS_UART_CR) &
840 (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
841 cpu_relax();
842
843 /*
844 * Clear the RX disable bit and then set the RX enable bit to enable
845 * the receiver.
846 */
847 status = readl(port->membase + CDNS_UART_CR);
848 status &= ~CDNS_UART_CR_RX_DIS;
849 status |= CDNS_UART_CR_RX_EN;
850 writel(status, port->membase + CDNS_UART_CR);
851
852 /* Set the Mode Register with normal mode,8 data bits,1 stop bit,
853 * no parity.
854 */
855 writel(CDNS_UART_MR_CHMODE_NORM | CDNS_UART_MR_STOPMODE_1_BIT
856 | CDNS_UART_MR_PARITY_NONE | CDNS_UART_MR_CHARLEN_8_BIT,
857 port->membase + CDNS_UART_MR);
858
859 /*
860 * Set the RX FIFO Trigger level to use most of the FIFO, but it
861 * can be tuned with a module parameter
862 */
863 writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);
864
865 /*
866 * Receive Timeout register is enabled but it
867 * can be tuned with a module parameter
868 */
869 writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
870
871 /* Clear out any pending interrupts before enabling them */
872 writel(readl(port->membase + CDNS_UART_ISR),
873 port->membase + CDNS_UART_ISR);
874
875 spin_unlock_irqrestore(&port->lock, flags);
876
877 ret = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME, port);
878 if (ret) {
879 dev_err(port->dev, "request_irq '%d' failed with %d\n",
880 port->irq, ret);
881 return ret;
882 }
883
884 /* Set the Interrupt Registers with desired interrupts */
885 if (is_brk_support)
886 writel(CDNS_UART_RX_IRQS | CDNS_UART_IXR_BRK,
887 port->membase + CDNS_UART_IER);
888 else
889 writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER);
890
891 return 0;
892}
893
894/**
895 * cdns_uart_shutdown - Called when an application closes a cdns_uart port
896 * @port: Handle to the uart port structure
897 */
898static void cdns_uart_shutdown(struct uart_port *port)
899{
900 int status;
901 unsigned long flags;
902
903 spin_lock_irqsave(&port->lock, flags);
904
905 /* Disable interrupts */
906 status = readl(port->membase + CDNS_UART_IMR);
907 writel(status, port->membase + CDNS_UART_IDR);
908 writel(0xffffffff, port->membase + CDNS_UART_ISR);
909
910 /* Disable the TX and RX */
911 writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
912 port->membase + CDNS_UART_CR);
913
914 spin_unlock_irqrestore(&port->lock, flags);
915
916 free_irq(port->irq, port);
917}
918
919/**
920 * cdns_uart_type - Set UART type to cdns_uart port
921 * @port: Handle to the uart port structure
922 *
923 * Return: string on success, NULL otherwise
924 */
925static const char *cdns_uart_type(struct uart_port *port)
926{
927 return port->type == PORT_XUARTPS ? CDNS_UART_NAME : NULL;
928}
929
930/**
931 * cdns_uart_verify_port - Verify the port params
932 * @port: Handle to the uart port structure
933 * @ser: Handle to the structure whose members are compared
934 *
935 * Return: 0 on success, negative errno otherwise.
936 */
937static int cdns_uart_verify_port(struct uart_port *port,
938 struct serial_struct *ser)
939{
940 if (ser->type != PORT_UNKNOWN && ser->type != PORT_XUARTPS)
941 return -EINVAL;
942 if (port->irq != ser->irq)
943 return -EINVAL;
944 if (ser->io_type != UPIO_MEM)
945 return -EINVAL;
946 if (port->iobase != ser->port)
947 return -EINVAL;
948 if (ser->hub6 != 0)
949 return -EINVAL;
950 return 0;
951}
952
953/**
954 * cdns_uart_request_port - Claim the memory region attached to cdns_uart port,
955 * called when the driver adds a cdns_uart port via
956 * uart_add_one_port()
957 * @port: Handle to the uart port structure
958 *
959 * Return: 0 on success, negative errno otherwise.
960 */
961static int cdns_uart_request_port(struct uart_port *port)
962{
963 if (!request_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE,
964 CDNS_UART_NAME)) {
965 return -ENOMEM;
966 }
967
968 port->membase = ioremap(port->mapbase, CDNS_UART_REGISTER_SPACE);
969 if (!port->membase) {
970 dev_err(port->dev, "Unable to map registers\n");
971 release_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE);
972 return -ENOMEM;
973 }
974 return 0;
975}
976
977/**
978 * cdns_uart_release_port - Release UART port
979 * @port: Handle to the uart port structure
980 *
981 * Release the memory region attached to a cdns_uart port. Called when the
982 * driver removes a cdns_uart port via uart_remove_one_port().
983 */
984static void cdns_uart_release_port(struct uart_port *port)
985{
986 release_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE);
987 iounmap(port->membase);
988 port->membase = NULL;
989}
990
991/**
992 * cdns_uart_config_port - Configure UART port
993 * @port: Handle to the uart port structure
994 * @flags: If any
995 */
996static void cdns_uart_config_port(struct uart_port *port, int flags)
997{
998 if (flags & UART_CONFIG_TYPE && cdns_uart_request_port(port) == 0)
999 port->type = PORT_XUARTPS;
1000}
1001
1002/**
1003 * cdns_uart_get_mctrl - Get the modem control state
1004 * @port: Handle to the uart port structure
1005 *
1006 * Return: the modem control state
1007 */
1008static unsigned int cdns_uart_get_mctrl(struct uart_port *port)
1009{
1010 struct cdns_uart *cdns_uart_data = port->private_data;
1011
1012 if (cdns_uart_data->cts_override)
1013 return 0;
1014
1015 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
1016}
1017
1018static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
1019{
1020 u32 val;
1021 u32 mode_reg;
1022 struct cdns_uart *cdns_uart_data = port->private_data;
1023
1024 if (cdns_uart_data->cts_override)
1025 return;
1026
1027 val = readl(port->membase + CDNS_UART_MODEMCR);
1028 mode_reg = readl(port->membase + CDNS_UART_MR);
1029
1030 val &= ~(CDNS_UART_MODEMCR_RTS | CDNS_UART_MODEMCR_DTR |
1031 CDNS_UART_MODEMCR_FCM);
1032 mode_reg &= ~CDNS_UART_MR_CHMODE_MASK;
1033
1034 if (mctrl & TIOCM_RTS || mctrl & TIOCM_DTR)
1035 val |= CDNS_UART_MODEMCR_FCM;
1036 if (mctrl & TIOCM_LOOP)
1037 mode_reg |= CDNS_UART_MR_CHMODE_L_LOOP;
1038 else
1039 mode_reg |= CDNS_UART_MR_CHMODE_NORM;
1040
1041 writel(val, port->membase + CDNS_UART_MODEMCR);
1042 writel(mode_reg, port->membase + CDNS_UART_MR);
1043}
1044
1045#ifdef CONFIG_CONSOLE_POLL
1046static int cdns_uart_poll_get_char(struct uart_port *port)
1047{
1048 int c;
1049 unsigned long flags;
1050
1051 spin_lock_irqsave(&port->lock, flags);
1052
1053 /* Check if FIFO is empty */
1054 if (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_RXEMPTY)
1055 c = NO_POLL_CHAR;
1056 else /* Read a character */
1057 c = (unsigned char) readl(port->membase + CDNS_UART_FIFO);
1058
1059 spin_unlock_irqrestore(&port->lock, flags);
1060
1061 return c;
1062}
1063
1064static void cdns_uart_poll_put_char(struct uart_port *port, unsigned char c)
1065{
1066 unsigned long flags;
1067
1068 spin_lock_irqsave(&port->lock, flags);
1069
1070 /* Wait until FIFO is empty */
1071 while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))
1072 cpu_relax();
1073
1074 /* Write a character */
1075 writel(c, port->membase + CDNS_UART_FIFO);
1076
1077 /* Wait until FIFO is empty */
1078 while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))
1079 cpu_relax();
1080
1081 spin_unlock_irqrestore(&port->lock, flags);
1082}
1083#endif
1084
1085static void cdns_uart_pm(struct uart_port *port, unsigned int state,
1086 unsigned int oldstate)
1087{
1088 switch (state) {
1089 case UART_PM_STATE_OFF:
1090 pm_runtime_mark_last_busy(port->dev);
1091 pm_runtime_put_autosuspend(port->dev);
1092 break;
1093 default:
1094 pm_runtime_get_sync(port->dev);
1095 break;
1096 }
1097}
1098
1099static const struct uart_ops cdns_uart_ops = {
1100 .set_mctrl = cdns_uart_set_mctrl,
1101 .get_mctrl = cdns_uart_get_mctrl,
1102 .start_tx = cdns_uart_start_tx,
1103 .stop_tx = cdns_uart_stop_tx,
1104 .stop_rx = cdns_uart_stop_rx,
1105 .tx_empty = cdns_uart_tx_empty,
1106 .break_ctl = cdns_uart_break_ctl,
1107 .set_termios = cdns_uart_set_termios,
1108 .startup = cdns_uart_startup,
1109 .shutdown = cdns_uart_shutdown,
1110 .pm = cdns_uart_pm,
1111 .type = cdns_uart_type,
1112 .verify_port = cdns_uart_verify_port,
1113 .request_port = cdns_uart_request_port,
1114 .release_port = cdns_uart_release_port,
1115 .config_port = cdns_uart_config_port,
1116#ifdef CONFIG_CONSOLE_POLL
1117 .poll_get_char = cdns_uart_poll_get_char,
1118 .poll_put_char = cdns_uart_poll_put_char,
1119#endif
1120};
1121
1122#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1123/**
1124 * cdns_uart_console_putchar - write the character to the FIFO buffer
1125 * @port: Handle to the uart port structure
1126 * @ch: Character to be written
1127 */
1128static void cdns_uart_console_putchar(struct uart_port *port, int ch)
1129{
1130 while (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)
1131 cpu_relax();
1132 writel(ch, port->membase + CDNS_UART_FIFO);
1133}
1134
1135static void cdns_early_write(struct console *con, const char *s,
1136 unsigned n)
1137{
1138 struct earlycon_device *dev = con->data;
1139
1140 uart_console_write(&dev->port, s, n, cdns_uart_console_putchar);
1141}
1142
1143static int __init cdns_early_console_setup(struct earlycon_device *device,
1144 const char *opt)
1145{
1146 struct uart_port *port = &device->port;
1147
1148 if (!port->membase)
1149 return -ENODEV;
1150
1151 /* initialise control register */
1152 writel(CDNS_UART_CR_TX_EN|CDNS_UART_CR_TXRST|CDNS_UART_CR_RXRST,
1153 port->membase + CDNS_UART_CR);
1154
1155 /* only set baud if specified on command line - otherwise
1156 * assume it has been initialized by a boot loader.
1157 */
1158 if (port->uartclk && device->baud) {
1159 u32 cd = 0, bdiv = 0;
1160 u32 mr;
1161 int div8;
1162
1163 cdns_uart_calc_baud_divs(port->uartclk, device->baud,
1164 &bdiv, &cd, &div8);
1165 mr = CDNS_UART_MR_PARITY_NONE;
1166 if (div8)
1167 mr |= CDNS_UART_MR_CLKSEL;
1168
1169 writel(mr, port->membase + CDNS_UART_MR);
1170 writel(cd, port->membase + CDNS_UART_BAUDGEN);
1171 writel(bdiv, port->membase + CDNS_UART_BAUDDIV);
1172 }
1173
1174 device->con->write = cdns_early_write;
1175
1176 return 0;
1177}
1178OF_EARLYCON_DECLARE(cdns, "xlnx,xuartps", cdns_early_console_setup);
1179OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p8", cdns_early_console_setup);
1180OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p12", cdns_early_console_setup);
1181OF_EARLYCON_DECLARE(cdns, "xlnx,zynqmp-uart", cdns_early_console_setup);
1182
1183
1184/* Static pointer to console port */
1185static struct uart_port *console_port;
1186
1187/**
1188 * cdns_uart_console_write - perform write operation
1189 * @co: Console handle
1190 * @s: Pointer to character array
1191 * @count: No of characters
1192 */
1193static void cdns_uart_console_write(struct console *co, const char *s,
1194 unsigned int count)
1195{
1196 struct uart_port *port = console_port;
1197 unsigned long flags = 0;
1198 unsigned int imr, ctrl;
1199 int locked = 1;
1200
1201 if (port->sysrq)
1202 locked = 0;
1203 else if (oops_in_progress)
1204 locked = spin_trylock_irqsave(&port->lock, flags);
1205 else
1206 spin_lock_irqsave(&port->lock, flags);
1207
1208 /* save and disable interrupt */
1209 imr = readl(port->membase + CDNS_UART_IMR);
1210 writel(imr, port->membase + CDNS_UART_IDR);
1211
1212 /*
1213 * Make sure that the tx part is enabled. Set the TX enable bit and
1214 * clear the TX disable bit to enable the transmitter.
1215 */
1216 ctrl = readl(port->membase + CDNS_UART_CR);
1217 ctrl &= ~CDNS_UART_CR_TX_DIS;
1218 ctrl |= CDNS_UART_CR_TX_EN;
1219 writel(ctrl, port->membase + CDNS_UART_CR);
1220
1221 uart_console_write(port, s, count, cdns_uart_console_putchar);
1222 while ((readl(port->membase + CDNS_UART_SR) &
1223 (CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE)) !=
1224 CDNS_UART_SR_TXEMPTY)
1225 cpu_relax();
1226
1227 /* restore interrupt state */
1228 writel(imr, port->membase + CDNS_UART_IER);
1229
1230 if (locked)
1231 spin_unlock_irqrestore(&port->lock, flags);
1232}
1233
1234/**
1235 * cdns_uart_console_setup - Initialize the uart to default config
1236 * @co: Console handle
1237 * @options: Initial settings of uart
1238 *
1239 * Return: 0 on success, negative errno otherwise.
1240 */
1241static int cdns_uart_console_setup(struct console *co, char *options)
1242{
1243 struct uart_port *port = console_port;
1244
1245 int baud = 9600;
1246 int bits = 8;
1247 int parity = 'n';
1248 int flow = 'n';
1249
1250 if (!port->membase) {
1251 pr_debug("console on " CDNS_UART_TTY_NAME "%i not present\n",
1252 co->index);
1253 return -ENODEV;
1254 }
1255
1256 if (options)
1257 uart_parse_options(options, &baud, &parity, &bits, &flow);
1258
1259 return uart_set_options(port, co, baud, parity, bits, flow);
1260}
1261#endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */
1262
1263#ifdef CONFIG_PM_SLEEP
1264/**
1265 * cdns_uart_suspend - suspend event
1266 * @device: Pointer to the device structure
1267 *
1268 * Return: 0
1269 */
1270static int cdns_uart_suspend(struct device *device)
1271{
1272 struct uart_port *port = dev_get_drvdata(device);
1273 struct cdns_uart *cdns_uart = port->private_data;
1274 int may_wake;
1275
1276 may_wake = device_may_wakeup(device);
1277
1278 if (console_suspend_enabled && uart_console(port) && may_wake) {
1279 unsigned long flags = 0;
1280
1281 spin_lock_irqsave(&port->lock, flags);
1282 /* Empty the receive FIFO 1st before making changes */
1283 while (!(readl(port->membase + CDNS_UART_SR) &
1284 CDNS_UART_SR_RXEMPTY))
1285 readl(port->membase + CDNS_UART_FIFO);
1286 /* set RX trigger level to 1 */
1287 writel(1, port->membase + CDNS_UART_RXWM);
1288 /* disable RX timeout interrups */
1289 writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IDR);
1290 spin_unlock_irqrestore(&port->lock, flags);
1291 }
1292
1293 /*
1294 * Call the API provided in serial_core.c file which handles
1295 * the suspend.
1296 */
1297 return uart_suspend_port(cdns_uart->cdns_uart_driver, port);
1298}
1299
1300/**
1301 * cdns_uart_resume - Resume after a previous suspend
1302 * @device: Pointer to the device structure
1303 *
1304 * Return: 0
1305 */
1306static int cdns_uart_resume(struct device *device)
1307{
1308 struct uart_port *port = dev_get_drvdata(device);
1309 struct cdns_uart *cdns_uart = port->private_data;
1310 unsigned long flags = 0;
1311 u32 ctrl_reg;
1312 int may_wake;
1313
1314 may_wake = device_may_wakeup(device);
1315
1316 if (console_suspend_enabled && uart_console(port) && !may_wake) {
1317 clk_enable(cdns_uart->pclk);
1318 clk_enable(cdns_uart->uartclk);
1319
1320 spin_lock_irqsave(&port->lock, flags);
1321
1322 /* Set TX/RX Reset */
1323 ctrl_reg = readl(port->membase + CDNS_UART_CR);
1324 ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
1325 writel(ctrl_reg, port->membase + CDNS_UART_CR);
1326 while (readl(port->membase + CDNS_UART_CR) &
1327 (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
1328 cpu_relax();
1329
1330 /* restore rx timeout value */
1331 writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
1332 /* Enable Tx/Rx */
1333 ctrl_reg = readl(port->membase + CDNS_UART_CR);
1334 ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
1335 ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
1336 writel(ctrl_reg, port->membase + CDNS_UART_CR);
1337
1338 clk_disable(cdns_uart->uartclk);
1339 clk_disable(cdns_uart->pclk);
1340 spin_unlock_irqrestore(&port->lock, flags);
1341 } else {
1342 spin_lock_irqsave(&port->lock, flags);
1343 /* restore original rx trigger level */
1344 writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);
1345 /* enable RX timeout interrupt */
1346 writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IER);
1347 spin_unlock_irqrestore(&port->lock, flags);
1348 }
1349
1350 return uart_resume_port(cdns_uart->cdns_uart_driver, port);
1351}
1352#endif /* ! CONFIG_PM_SLEEP */
1353static int __maybe_unused cdns_runtime_suspend(struct device *dev)
1354{
1355 struct uart_port *port = dev_get_drvdata(dev);
1356 struct cdns_uart *cdns_uart = port->private_data;
1357
1358 clk_disable(cdns_uart->uartclk);
1359 clk_disable(cdns_uart->pclk);
1360 return 0;
1361};
1362
1363static int __maybe_unused cdns_runtime_resume(struct device *dev)
1364{
1365 struct uart_port *port = dev_get_drvdata(dev);
1366 struct cdns_uart *cdns_uart = port->private_data;
1367
1368 clk_enable(cdns_uart->pclk);
1369 clk_enable(cdns_uart->uartclk);
1370 return 0;
1371};
1372
1373static const struct dev_pm_ops cdns_uart_dev_pm_ops = {
1374 SET_SYSTEM_SLEEP_PM_OPS(cdns_uart_suspend, cdns_uart_resume)
1375 SET_RUNTIME_PM_OPS(cdns_runtime_suspend,
1376 cdns_runtime_resume, NULL)
1377};
1378
1379static const struct cdns_platform_data zynqmp_uart_def = {
1380 .quirks = CDNS_UART_RXBS_SUPPORT, };
1381
1382/* Match table for of_platform binding */
1383static const struct of_device_id cdns_uart_of_match[] = {
1384 { .compatible = "xlnx,xuartps", },
1385 { .compatible = "cdns,uart-r1p8", },
1386 { .compatible = "cdns,uart-r1p12", .data = &zynqmp_uart_def },
1387 { .compatible = "xlnx,zynqmp-uart", .data = &zynqmp_uart_def },
1388 {}
1389};
1390MODULE_DEVICE_TABLE(of, cdns_uart_of_match);
1391
1392/*
1393 * Maximum number of instances without alias IDs but if there is alias
1394 * which target "< MAX_UART_INSTANCES" range this ID can't be used.
1395 */
1396#define MAX_UART_INSTANCES 32
1397
1398/* Stores static aliases list */
1399static DECLARE_BITMAP(alias_bitmap, MAX_UART_INSTANCES);
1400static int alias_bitmap_initialized;
1401
1402/* Stores actual bitmap of allocated IDs with alias IDs together */
1403static DECLARE_BITMAP(bitmap, MAX_UART_INSTANCES);
1404/* Protect bitmap operations to have unique IDs */
1405static DEFINE_MUTEX(bitmap_lock);
1406
1407static int cdns_get_id(struct platform_device *pdev)
1408{
1409 int id, ret;
1410
1411 mutex_lock(&bitmap_lock);
1412
1413 /* Alias list is stable that's why get alias bitmap only once */
1414 if (!alias_bitmap_initialized) {
1415 ret = of_alias_get_alias_list(cdns_uart_of_match, "serial",
1416 alias_bitmap, MAX_UART_INSTANCES);
1417 if (ret && ret != -EOVERFLOW) {
1418 mutex_unlock(&bitmap_lock);
1419 return ret;
1420 }
1421
1422 alias_bitmap_initialized++;
1423 }
1424
1425 /* Make sure that alias ID is not taken by instance without alias */
1426 bitmap_or(bitmap, bitmap, alias_bitmap, MAX_UART_INSTANCES);
1427
1428 dev_dbg(&pdev->dev, "Alias bitmap: %*pb\n",
1429 MAX_UART_INSTANCES, bitmap);
1430
1431 /* Look for a serialN alias */
1432 id = of_alias_get_id(pdev->dev.of_node, "serial");
1433 if (id < 0) {
1434 dev_warn(&pdev->dev,
1435 "No serial alias passed. Using the first free id\n");
1436
1437 /*
1438 * Start with id 0 and check if there is no serial0 alias
1439 * which points to device which is compatible with this driver.
1440 * If alias exists then try next free position.
1441 */
1442 id = 0;
1443
1444 for (;;) {
1445 dev_info(&pdev->dev, "Checking id %d\n", id);
1446 id = find_next_zero_bit(bitmap, MAX_UART_INSTANCES, id);
1447
1448 /* No free empty instance */
1449 if (id == MAX_UART_INSTANCES) {
1450 dev_err(&pdev->dev, "No free ID\n");
1451 mutex_unlock(&bitmap_lock);
1452 return -EINVAL;
1453 }
1454
1455 dev_dbg(&pdev->dev, "The empty id is %d\n", id);
1456 /* Check if ID is empty */
1457 if (!test_and_set_bit(id, bitmap)) {
1458 /* Break the loop if bit is taken */
1459 dev_dbg(&pdev->dev,
1460 "Selected ID %d allocation passed\n",
1461 id);
1462 break;
1463 }
1464 dev_dbg(&pdev->dev,
1465 "Selected ID %d allocation failed\n", id);
1466 /* if taking bit fails then try next one */
1467 id++;
1468 }
1469 }
1470
1471 mutex_unlock(&bitmap_lock);
1472
1473 return id;
1474}
1475
1476/**
1477 * cdns_uart_probe - Platform driver probe
1478 * @pdev: Pointer to the platform device structure
1479 *
1480 * Return: 0 on success, negative errno otherwise
1481 */
1482static int cdns_uart_probe(struct platform_device *pdev)
1483{
1484 int rc, irq;
1485 struct uart_port *port;
1486 struct resource *res;
1487 struct cdns_uart *cdns_uart_data;
1488 const struct of_device_id *match;
1489 struct uart_driver *cdns_uart_uart_driver;
1490 char *driver_name;
1491#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1492 struct console *cdns_uart_console;
1493#endif
1494
1495 cdns_uart_data = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_data),
1496 GFP_KERNEL);
1497 if (!cdns_uart_data)
1498 return -ENOMEM;
1499 port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
1500 if (!port)
1501 return -ENOMEM;
1502
1503 cdns_uart_uart_driver = devm_kzalloc(&pdev->dev,
1504 sizeof(*cdns_uart_uart_driver),
1505 GFP_KERNEL);
1506 if (!cdns_uart_uart_driver)
1507 return -ENOMEM;
1508
1509 cdns_uart_data->id = cdns_get_id(pdev);
1510 if (cdns_uart_data->id < 0)
1511 return cdns_uart_data->id;
1512
1513 /* There is a need to use unique driver name */
1514 driver_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s%d",
1515 CDNS_UART_NAME, cdns_uart_data->id);
1516 if (!driver_name) {
1517 rc = -ENOMEM;
1518 goto err_out_id;
1519 }
1520
1521 cdns_uart_uart_driver->owner = THIS_MODULE;
1522 cdns_uart_uart_driver->driver_name = driver_name;
1523 cdns_uart_uart_driver->dev_name = CDNS_UART_TTY_NAME;
1524 cdns_uart_uart_driver->major = uartps_major;
1525 cdns_uart_uart_driver->minor = cdns_uart_data->id;
1526 cdns_uart_uart_driver->nr = 1;
1527
1528#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1529 cdns_uart_console = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_console),
1530 GFP_KERNEL);
1531 if (!cdns_uart_console) {
1532 rc = -ENOMEM;
1533 goto err_out_id;
1534 }
1535
1536 strncpy(cdns_uart_console->name, CDNS_UART_TTY_NAME,
1537 sizeof(cdns_uart_console->name));
1538 cdns_uart_console->index = cdns_uart_data->id;
1539 cdns_uart_console->write = cdns_uart_console_write;
1540 cdns_uart_console->device = uart_console_device;
1541 cdns_uart_console->setup = cdns_uart_console_setup;
1542 cdns_uart_console->flags = CON_PRINTBUFFER;
1543 cdns_uart_console->data = cdns_uart_uart_driver;
1544 cdns_uart_uart_driver->cons = cdns_uart_console;
1545#endif
1546
1547 rc = uart_register_driver(cdns_uart_uart_driver);
1548 if (rc < 0) {
1549 dev_err(&pdev->dev, "Failed to register driver\n");
1550 goto err_out_id;
1551 }
1552
1553 cdns_uart_data->cdns_uart_driver = cdns_uart_uart_driver;
1554
1555 /*
1556 * Setting up proper name_base needs to be done after uart
1557 * registration because tty_driver structure is not filled.
1558 * name_base is 0 by default.
1559 */
1560 cdns_uart_uart_driver->tty_driver->name_base = cdns_uart_data->id;
1561
1562 match = of_match_node(cdns_uart_of_match, pdev->dev.of_node);
1563 if (match && match->data) {
1564 const struct cdns_platform_data *data = match->data;
1565
1566 cdns_uart_data->quirks = data->quirks;
1567 }
1568
1569 cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "pclk");
1570 if (PTR_ERR(cdns_uart_data->pclk) == -EPROBE_DEFER) {
1571 rc = PTR_ERR(cdns_uart_data->pclk);
1572 goto err_out_unregister_driver;
1573 }
1574
1575 if (IS_ERR(cdns_uart_data->pclk)) {
1576 cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "aper_clk");
1577 if (IS_ERR(cdns_uart_data->pclk)) {
1578 rc = PTR_ERR(cdns_uart_data->pclk);
1579 goto err_out_unregister_driver;
1580 }
1581 dev_err(&pdev->dev, "clock name 'aper_clk' is deprecated.\n");
1582 }
1583
1584 cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");
1585 if (PTR_ERR(cdns_uart_data->uartclk) == -EPROBE_DEFER) {
1586 rc = PTR_ERR(cdns_uart_data->uartclk);
1587 goto err_out_unregister_driver;
1588 }
1589
1590 if (IS_ERR(cdns_uart_data->uartclk)) {
1591 cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "ref_clk");
1592 if (IS_ERR(cdns_uart_data->uartclk)) {
1593 rc = PTR_ERR(cdns_uart_data->uartclk);
1594 goto err_out_unregister_driver;
1595 }
1596 dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n");
1597 }
1598
1599 rc = clk_prepare_enable(cdns_uart_data->pclk);
1600 if (rc) {
1601 dev_err(&pdev->dev, "Unable to enable pclk clock.\n");
1602 goto err_out_unregister_driver;
1603 }
1604 rc = clk_prepare_enable(cdns_uart_data->uartclk);
1605 if (rc) {
1606 dev_err(&pdev->dev, "Unable to enable device clock.\n");
1607 goto err_out_clk_dis_pclk;
1608 }
1609
1610 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1611 if (!res) {
1612 rc = -ENODEV;
1613 goto err_out_clk_disable;
1614 }
1615
1616 irq = platform_get_irq(pdev, 0);
1617 if (irq <= 0) {
1618 rc = -ENXIO;
1619 goto err_out_clk_disable;
1620 }
1621
1622#ifdef CONFIG_COMMON_CLK
1623 cdns_uart_data->clk_rate_change_nb.notifier_call =
1624 cdns_uart_clk_notifier_cb;
1625 if (clk_notifier_register(cdns_uart_data->uartclk,
1626 &cdns_uart_data->clk_rate_change_nb))
1627 dev_warn(&pdev->dev, "Unable to register clock notifier.\n");
1628#endif
1629
1630 /* At this point, we've got an empty uart_port struct, initialize it */
1631 spin_lock_init(&port->lock);
1632 port->type = PORT_UNKNOWN;
1633 port->iotype = UPIO_MEM32;
1634 port->flags = UPF_BOOT_AUTOCONF;
1635 port->ops = &cdns_uart_ops;
1636 port->fifosize = CDNS_UART_FIFO_SIZE;
1637
1638 /*
1639 * Register the port.
1640 * This function also registers this device with the tty layer
1641 * and triggers invocation of the config_port() entry point.
1642 */
1643 port->mapbase = res->start;
1644 port->irq = irq;
1645 port->dev = &pdev->dev;
1646 port->uartclk = clk_get_rate(cdns_uart_data->uartclk);
1647 port->private_data = cdns_uart_data;
1648 cdns_uart_data->port = port;
1649 platform_set_drvdata(pdev, port);
1650
1651 pm_runtime_use_autosuspend(&pdev->dev);
1652 pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
1653 pm_runtime_set_active(&pdev->dev);
1654 pm_runtime_enable(&pdev->dev);
1655 device_init_wakeup(port->dev, true);
1656
1657#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1658 /*
1659 * If console hasn't been found yet try to assign this port
1660 * because it is required to be assigned for console setup function.
1661 * If register_console() don't assign value, then console_port pointer
1662 * is cleanup.
1663 */
1664 if (!console_port)
1665 console_port = port;
1666#endif
1667
1668 rc = uart_add_one_port(cdns_uart_uart_driver, port);
1669 if (rc) {
1670 dev_err(&pdev->dev,
1671 "uart_add_one_port() failed; err=%i\n", rc);
1672 goto err_out_pm_disable;
1673 }
1674
1675#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1676 /* This is not port which is used for console that's why clean it up */
1677 if (console_port == port &&
1678 !(cdns_uart_uart_driver->cons->flags & CON_ENABLED))
1679 console_port = NULL;
1680#endif
1681
1682 uartps_major = cdns_uart_uart_driver->tty_driver->major;
1683 cdns_uart_data->cts_override = of_property_read_bool(pdev->dev.of_node,
1684 "cts-override");
1685 return 0;
1686
1687err_out_pm_disable:
1688 pm_runtime_disable(&pdev->dev);
1689 pm_runtime_set_suspended(&pdev->dev);
1690 pm_runtime_dont_use_autosuspend(&pdev->dev);
1691#ifdef CONFIG_COMMON_CLK
1692 clk_notifier_unregister(cdns_uart_data->uartclk,
1693 &cdns_uart_data->clk_rate_change_nb);
1694#endif
1695err_out_clk_disable:
1696 clk_disable_unprepare(cdns_uart_data->uartclk);
1697err_out_clk_dis_pclk:
1698 clk_disable_unprepare(cdns_uart_data->pclk);
1699err_out_unregister_driver:
1700 uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
1701err_out_id:
1702 mutex_lock(&bitmap_lock);
1703 if (cdns_uart_data->id < MAX_UART_INSTANCES)
1704 clear_bit(cdns_uart_data->id, bitmap);
1705 mutex_unlock(&bitmap_lock);
1706 return rc;
1707}
1708
1709/**
1710 * cdns_uart_remove - called when the platform driver is unregistered
1711 * @pdev: Pointer to the platform device structure
1712 *
1713 * Return: 0 on success, negative errno otherwise
1714 */
1715static int cdns_uart_remove(struct platform_device *pdev)
1716{
1717 struct uart_port *port = platform_get_drvdata(pdev);
1718 struct cdns_uart *cdns_uart_data = port->private_data;
1719 int rc;
1720
1721 /* Remove the cdns_uart port from the serial core */
1722#ifdef CONFIG_COMMON_CLK
1723 clk_notifier_unregister(cdns_uart_data->uartclk,
1724 &cdns_uart_data->clk_rate_change_nb);
1725#endif
1726 rc = uart_remove_one_port(cdns_uart_data->cdns_uart_driver, port);
1727 port->mapbase = 0;
1728 mutex_lock(&bitmap_lock);
1729 if (cdns_uart_data->id < MAX_UART_INSTANCES)
1730 clear_bit(cdns_uart_data->id, bitmap);
1731 mutex_unlock(&bitmap_lock);
1732 clk_disable_unprepare(cdns_uart_data->uartclk);
1733 clk_disable_unprepare(cdns_uart_data->pclk);
1734 pm_runtime_disable(&pdev->dev);
1735 pm_runtime_set_suspended(&pdev->dev);
1736 pm_runtime_dont_use_autosuspend(&pdev->dev);
1737 device_init_wakeup(&pdev->dev, false);
1738
1739#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1740 if (console_port == port)
1741 console_port = NULL;
1742#endif
1743
1744 /* If this is last instance major number should be initialized */
1745 mutex_lock(&bitmap_lock);
1746 if (bitmap_empty(bitmap, MAX_UART_INSTANCES))
1747 uartps_major = 0;
1748 mutex_unlock(&bitmap_lock);
1749
1750 uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
1751 return rc;
1752}
1753
1754static struct platform_driver cdns_uart_platform_driver = {
1755 .probe = cdns_uart_probe,
1756 .remove = cdns_uart_remove,
1757 .driver = {
1758 .name = CDNS_UART_NAME,
1759 .of_match_table = cdns_uart_of_match,
1760 .pm = &cdns_uart_dev_pm_ops,
1761 .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_XILINX_PS_UART),
1762 },
1763};
1764
1765static int __init cdns_uart_init(void)
1766{
1767 /* Register the platform driver */
1768 return platform_driver_register(&cdns_uart_platform_driver);
1769}
1770
1771static void __exit cdns_uart_exit(void)
1772{
1773 /* Unregister the platform driver */
1774 platform_driver_unregister(&cdns_uart_platform_driver);
1775}
1776
1777arch_initcall(cdns_uart_init);
1778module_exit(cdns_uart_exit);
1779
1780MODULE_DESCRIPTION("Driver for Cadence UART");
1781MODULE_AUTHOR("Xilinx Inc.");
1782MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Cadence UART driver (found in Xilinx Zynq)
4 *
5 * 2011 - 2014 (C) Xilinx Inc.
6 *
7 * This driver has originally been pushed by Xilinx using a Zynq-branding. This
8 * still shows in the naming of this file, the kconfig symbols and some symbols
9 * in the code.
10 */
11
12#include <linux/platform_device.h>
13#include <linux/serial.h>
14#include <linux/console.h>
15#include <linux/serial_core.h>
16#include <linux/slab.h>
17#include <linux/tty.h>
18#include <linux/tty_flip.h>
19#include <linux/clk.h>
20#include <linux/irq.h>
21#include <linux/io.h>
22#include <linux/of.h>
23#include <linux/module.h>
24#include <linux/pm_runtime.h>
25#include <linux/iopoll.h>
26
27#define CDNS_UART_TTY_NAME "ttyPS"
28#define CDNS_UART_NAME "xuartps"
29#define CDNS_UART_MAJOR 0 /* use dynamic node allocation */
30#define CDNS_UART_MINOR 0 /* works best with devtmpfs */
31#define CDNS_UART_NR_PORTS 16
32#define CDNS_UART_FIFO_SIZE 64 /* FIFO size */
33#define CDNS_UART_REGISTER_SPACE 0x1000
34#define TX_TIMEOUT 500000
35
36/* Rx Trigger level */
37static int rx_trigger_level = 56;
38module_param(rx_trigger_level, uint, 0444);
39MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");
40
41/* Rx Timeout */
42static int rx_timeout = 10;
43module_param(rx_timeout, uint, 0444);
44MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
45
46/* Register offsets for the UART. */
47#define CDNS_UART_CR 0x00 /* Control Register */
48#define CDNS_UART_MR 0x04 /* Mode Register */
49#define CDNS_UART_IER 0x08 /* Interrupt Enable */
50#define CDNS_UART_IDR 0x0C /* Interrupt Disable */
51#define CDNS_UART_IMR 0x10 /* Interrupt Mask */
52#define CDNS_UART_ISR 0x14 /* Interrupt Status */
53#define CDNS_UART_BAUDGEN 0x18 /* Baud Rate Generator */
54#define CDNS_UART_RXTOUT 0x1C /* RX Timeout */
55#define CDNS_UART_RXWM 0x20 /* RX FIFO Trigger Level */
56#define CDNS_UART_MODEMCR 0x24 /* Modem Control */
57#define CDNS_UART_MODEMSR 0x28 /* Modem Status */
58#define CDNS_UART_SR 0x2C /* Channel Status */
59#define CDNS_UART_FIFO 0x30 /* FIFO */
60#define CDNS_UART_BAUDDIV 0x34 /* Baud Rate Divider */
61#define CDNS_UART_FLOWDEL 0x38 /* Flow Delay */
62#define CDNS_UART_IRRX_PWIDTH 0x3C /* IR Min Received Pulse Width */
63#define CDNS_UART_IRTX_PWIDTH 0x40 /* IR Transmitted pulse Width */
64#define CDNS_UART_TXWM 0x44 /* TX FIFO Trigger Level */
65#define CDNS_UART_RXBS 0x48 /* RX FIFO byte status register */
66
67/* Control Register Bit Definitions */
68#define CDNS_UART_CR_STOPBRK 0x00000100 /* Stop TX break */
69#define CDNS_UART_CR_STARTBRK 0x00000080 /* Set TX break */
70#define CDNS_UART_CR_TX_DIS 0x00000020 /* TX disabled. */
71#define CDNS_UART_CR_TX_EN 0x00000010 /* TX enabled */
72#define CDNS_UART_CR_RX_DIS 0x00000008 /* RX disabled. */
73#define CDNS_UART_CR_RX_EN 0x00000004 /* RX enabled */
74#define CDNS_UART_CR_TXRST 0x00000002 /* TX logic reset */
75#define CDNS_UART_CR_RXRST 0x00000001 /* RX logic reset */
76#define CDNS_UART_CR_RST_TO 0x00000040 /* Restart Timeout Counter */
77#define CDNS_UART_RXBS_PARITY 0x00000001 /* Parity error status */
78#define CDNS_UART_RXBS_FRAMING 0x00000002 /* Framing error status */
79#define CDNS_UART_RXBS_BRK 0x00000004 /* Overrun error status */
80
81/*
82 * Mode Register:
83 * The mode register (MR) defines the mode of transfer as well as the data
84 * format. If this register is modified during transmission or reception,
85 * data validity cannot be guaranteed.
86 */
87#define CDNS_UART_MR_CLKSEL 0x00000001 /* Pre-scalar selection */
88#define CDNS_UART_MR_CHMODE_L_LOOP 0x00000200 /* Local loop back mode */
89#define CDNS_UART_MR_CHMODE_NORM 0x00000000 /* Normal mode */
90#define CDNS_UART_MR_CHMODE_MASK 0x00000300 /* Mask for mode bits */
91
92#define CDNS_UART_MR_STOPMODE_2_BIT 0x00000080 /* 2 stop bits */
93#define CDNS_UART_MR_STOPMODE_1_BIT 0x00000000 /* 1 stop bit */
94
95#define CDNS_UART_MR_PARITY_NONE 0x00000020 /* No parity mode */
96#define CDNS_UART_MR_PARITY_MARK 0x00000018 /* Mark parity mode */
97#define CDNS_UART_MR_PARITY_SPACE 0x00000010 /* Space parity mode */
98#define CDNS_UART_MR_PARITY_ODD 0x00000008 /* Odd parity mode */
99#define CDNS_UART_MR_PARITY_EVEN 0x00000000 /* Even parity mode */
100
101#define CDNS_UART_MR_CHARLEN_6_BIT 0x00000006 /* 6 bits data */
102#define CDNS_UART_MR_CHARLEN_7_BIT 0x00000004 /* 7 bits data */
103#define CDNS_UART_MR_CHARLEN_8_BIT 0x00000000 /* 8 bits data */
104
105/*
106 * Interrupt Registers:
107 * Interrupt control logic uses the interrupt enable register (IER) and the
108 * interrupt disable register (IDR) to set the value of the bits in the
109 * interrupt mask register (IMR). The IMR determines whether to pass an
110 * interrupt to the interrupt status register (ISR).
111 * Writing a 1 to IER Enables an interrupt, writing a 1 to IDR disables an
112 * interrupt. IMR and ISR are read only, and IER and IDR are write only.
113 * Reading either IER or IDR returns 0x00.
114 * All four registers have the same bit definitions.
115 */
116#define CDNS_UART_IXR_TOUT 0x00000100 /* RX Timeout error interrupt */
117#define CDNS_UART_IXR_PARITY 0x00000080 /* Parity error interrupt */
118#define CDNS_UART_IXR_FRAMING 0x00000040 /* Framing error interrupt */
119#define CDNS_UART_IXR_OVERRUN 0x00000020 /* Overrun error interrupt */
120#define CDNS_UART_IXR_TXFULL 0x00000010 /* TX FIFO Full interrupt */
121#define CDNS_UART_IXR_TXEMPTY 0x00000008 /* TX FIFO empty interrupt */
122#define CDNS_UART_ISR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt */
123#define CDNS_UART_IXR_RXTRIG 0x00000001 /* RX FIFO trigger interrupt */
124#define CDNS_UART_IXR_RXFULL 0x00000004 /* RX FIFO full interrupt. */
125#define CDNS_UART_IXR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt. */
126#define CDNS_UART_IXR_RXMASK 0x000021e7 /* Valid RX bit mask */
127
128 /*
129 * Do not enable parity error interrupt for the following
130 * reason: When parity error interrupt is enabled, each Rx
131 * parity error always results in 2 events. The first one
132 * being parity error interrupt and the second one with a
133 * proper Rx interrupt with the incoming data. Disabling
134 * parity error interrupt ensures better handling of parity
135 * error events. With this change, for a parity error case, we
136 * get a Rx interrupt with parity error set in ISR register
137 * and we still handle parity errors in the desired way.
138 */
139
140#define CDNS_UART_RX_IRQS (CDNS_UART_IXR_FRAMING | \
141 CDNS_UART_IXR_OVERRUN | \
142 CDNS_UART_IXR_RXTRIG | \
143 CDNS_UART_IXR_TOUT)
144
145/* Goes in read_status_mask for break detection as the HW doesn't do it*/
146#define CDNS_UART_IXR_BRK 0x00002000
147
148#define CDNS_UART_RXBS_SUPPORT BIT(1)
149/*
150 * Modem Control register:
151 * The read/write Modem Control register controls the interface with the modem
152 * or data set, or a peripheral device emulating a modem.
153 */
154#define CDNS_UART_MODEMCR_FCM 0x00000020 /* Automatic flow control mode */
155#define CDNS_UART_MODEMCR_RTS 0x00000002 /* Request to send output control */
156#define CDNS_UART_MODEMCR_DTR 0x00000001 /* Data Terminal Ready */
157
158/*
159 * Modem Status register:
160 * The read/write Modem Status register reports the interface with the modem
161 * or data set, or a peripheral device emulating a modem.
162 */
163#define CDNS_UART_MODEMSR_DCD BIT(7) /* Data Carrier Detect */
164#define CDNS_UART_MODEMSR_RI BIT(6) /* Ting Indicator */
165#define CDNS_UART_MODEMSR_DSR BIT(5) /* Data Set Ready */
166#define CDNS_UART_MODEMSR_CTS BIT(4) /* Clear To Send */
167
168/*
169 * Channel Status Register:
170 * The channel status register (CSR) is provided to enable the control logic
171 * to monitor the status of bits in the channel interrupt status register,
172 * even if these are masked out by the interrupt mask register.
173 */
174#define CDNS_UART_SR_RXEMPTY 0x00000002 /* RX FIFO empty */
175#define CDNS_UART_SR_TXEMPTY 0x00000008 /* TX FIFO empty */
176#define CDNS_UART_SR_TXFULL 0x00000010 /* TX FIFO full */
177#define CDNS_UART_SR_RXTRIG 0x00000001 /* Rx Trigger */
178#define CDNS_UART_SR_TACTIVE 0x00000800 /* TX state machine active */
179
180/* baud dividers min/max values */
181#define CDNS_UART_BDIV_MIN 4
182#define CDNS_UART_BDIV_MAX 255
183#define CDNS_UART_CD_MAX 65535
184#define UART_AUTOSUSPEND_TIMEOUT 3000
185
186/**
187 * struct cdns_uart - device data
188 * @port: Pointer to the UART port
189 * @uartclk: Reference clock
190 * @pclk: APB clock
191 * @cdns_uart_driver: Pointer to UART driver
192 * @baud: Current baud rate
193 * @clk_rate_change_nb: Notifier block for clock changes
194 * @quirks: Flags for RXBS support.
195 * @cts_override: Modem control state override
196 */
197struct cdns_uart {
198 struct uart_port *port;
199 struct clk *uartclk;
200 struct clk *pclk;
201 struct uart_driver *cdns_uart_driver;
202 unsigned int baud;
203 struct notifier_block clk_rate_change_nb;
204 u32 quirks;
205 bool cts_override;
206};
207struct cdns_platform_data {
208 u32 quirks;
209};
210#define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \
211 clk_rate_change_nb)
212
213/**
214 * cdns_uart_handle_rx - Handle the received bytes along with Rx errors.
215 * @dev_id: Id of the UART port
216 * @isrstatus: The interrupt status register value as read
217 * Return: None
218 */
219static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus)
220{
221 struct uart_port *port = (struct uart_port *)dev_id;
222 struct cdns_uart *cdns_uart = port->private_data;
223 unsigned int data;
224 unsigned int rxbs_status = 0;
225 unsigned int status_mask;
226 unsigned int framerrprocessed = 0;
227 char status = TTY_NORMAL;
228 bool is_rxbs_support;
229
230 is_rxbs_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;
231
232 while ((readl(port->membase + CDNS_UART_SR) &
233 CDNS_UART_SR_RXEMPTY) != CDNS_UART_SR_RXEMPTY) {
234 if (is_rxbs_support)
235 rxbs_status = readl(port->membase + CDNS_UART_RXBS);
236 data = readl(port->membase + CDNS_UART_FIFO);
237 port->icount.rx++;
238 /*
239 * There is no hardware break detection in Zynq, so we interpret
240 * framing error with all-zeros data as a break sequence.
241 * Most of the time, there's another non-zero byte at the
242 * end of the sequence.
243 */
244 if (!is_rxbs_support && (isrstatus & CDNS_UART_IXR_FRAMING)) {
245 if (!data) {
246 port->read_status_mask |= CDNS_UART_IXR_BRK;
247 framerrprocessed = 1;
248 continue;
249 }
250 }
251 if (is_rxbs_support && (rxbs_status & CDNS_UART_RXBS_BRK)) {
252 port->icount.brk++;
253 status = TTY_BREAK;
254 if (uart_handle_break(port))
255 continue;
256 }
257
258 isrstatus &= port->read_status_mask;
259 isrstatus &= ~port->ignore_status_mask;
260 status_mask = port->read_status_mask;
261 status_mask &= ~port->ignore_status_mask;
262
263 if (data &&
264 (port->read_status_mask & CDNS_UART_IXR_BRK)) {
265 port->read_status_mask &= ~CDNS_UART_IXR_BRK;
266 port->icount.brk++;
267 if (uart_handle_break(port))
268 continue;
269 }
270
271 if (uart_handle_sysrq_char(port, data))
272 continue;
273
274 if (is_rxbs_support) {
275 if ((rxbs_status & CDNS_UART_RXBS_PARITY)
276 && (status_mask & CDNS_UART_IXR_PARITY)) {
277 port->icount.parity++;
278 status = TTY_PARITY;
279 }
280 if ((rxbs_status & CDNS_UART_RXBS_FRAMING)
281 && (status_mask & CDNS_UART_IXR_PARITY)) {
282 port->icount.frame++;
283 status = TTY_FRAME;
284 }
285 } else {
286 if (isrstatus & CDNS_UART_IXR_PARITY) {
287 port->icount.parity++;
288 status = TTY_PARITY;
289 }
290 if ((isrstatus & CDNS_UART_IXR_FRAMING) &&
291 !framerrprocessed) {
292 port->icount.frame++;
293 status = TTY_FRAME;
294 }
295 }
296 if (isrstatus & CDNS_UART_IXR_OVERRUN) {
297 port->icount.overrun++;
298 tty_insert_flip_char(&port->state->port, 0,
299 TTY_OVERRUN);
300 }
301 tty_insert_flip_char(&port->state->port, data, status);
302 isrstatus = 0;
303 }
304
305 tty_flip_buffer_push(&port->state->port);
306}
307
308/**
309 * cdns_uart_handle_tx - Handle the bytes to be Txed.
310 * @dev_id: Id of the UART port
311 * Return: None
312 */
313static void cdns_uart_handle_tx(void *dev_id)
314{
315 struct uart_port *port = (struct uart_port *)dev_id;
316 unsigned int numbytes;
317
318 if (uart_circ_empty(&port->state->xmit)) {
319 writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR);
320 } else {
321 numbytes = port->fifosize;
322 while (numbytes && !uart_circ_empty(&port->state->xmit) &&
323 !(readl(port->membase + CDNS_UART_SR) &
324 CDNS_UART_SR_TXFULL)) {
325 /*
326 * Get the data from the UART circular buffer
327 * and write it to the cdns_uart's TX_FIFO
328 * register.
329 */
330 writel(
331 port->state->xmit.buf[port->state->xmit.tail],
332 port->membase + CDNS_UART_FIFO);
333
334 port->icount.tx++;
335
336 /*
337 * Adjust the tail of the UART buffer and wrap
338 * the buffer if it reaches limit.
339 */
340 port->state->xmit.tail =
341 (port->state->xmit.tail + 1) &
342 (UART_XMIT_SIZE - 1);
343
344 numbytes--;
345 }
346
347 if (uart_circ_chars_pending(
348 &port->state->xmit) < WAKEUP_CHARS)
349 uart_write_wakeup(port);
350 }
351}
352
353/**
354 * cdns_uart_isr - Interrupt handler
355 * @irq: Irq number
356 * @dev_id: Id of the port
357 *
358 * Return: IRQHANDLED
359 */
360static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
361{
362 struct uart_port *port = (struct uart_port *)dev_id;
363 unsigned int isrstatus;
364
365 spin_lock(&port->lock);
366
367 /* Read the interrupt status register to determine which
368 * interrupt(s) is/are active and clear them.
369 */
370 isrstatus = readl(port->membase + CDNS_UART_ISR);
371 writel(isrstatus, port->membase + CDNS_UART_ISR);
372
373 if (isrstatus & CDNS_UART_IXR_TXEMPTY) {
374 cdns_uart_handle_tx(dev_id);
375 isrstatus &= ~CDNS_UART_IXR_TXEMPTY;
376 }
377
378 /*
379 * Skip RX processing if RX is disabled as RXEMPTY will never be set
380 * as read bytes will not be removed from the FIFO.
381 */
382 if (isrstatus & CDNS_UART_IXR_RXMASK &&
383 !(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_RX_DIS))
384 cdns_uart_handle_rx(dev_id, isrstatus);
385
386 spin_unlock(&port->lock);
387 return IRQ_HANDLED;
388}
389
390/**
391 * cdns_uart_calc_baud_divs - Calculate baud rate divisors
392 * @clk: UART module input clock
393 * @baud: Desired baud rate
394 * @rbdiv: BDIV value (return value)
395 * @rcd: CD value (return value)
396 * @div8: Value for clk_sel bit in mod (return value)
397 * Return: baud rate, requested baud when possible, or actual baud when there
398 * was too much error, zero if no valid divisors are found.
399 *
400 * Formula to obtain baud rate is
401 * baud_tx/rx rate = clk/CD * (BDIV + 1)
402 * input_clk = (Uart User Defined Clock or Apb Clock)
403 * depends on UCLKEN in MR Reg
404 * clk = input_clk or input_clk/8;
405 * depends on CLKS in MR reg
406 * CD and BDIV depends on values in
407 * baud rate generate register
408 * baud rate clock divisor register
409 */
410static unsigned int cdns_uart_calc_baud_divs(unsigned int clk,
411 unsigned int baud, u32 *rbdiv, u32 *rcd, int *div8)
412{
413 u32 cd, bdiv;
414 unsigned int calc_baud;
415 unsigned int bestbaud = 0;
416 unsigned int bauderror;
417 unsigned int besterror = ~0;
418
419 if (baud < clk / ((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX)) {
420 *div8 = 1;
421 clk /= 8;
422 } else {
423 *div8 = 0;
424 }
425
426 for (bdiv = CDNS_UART_BDIV_MIN; bdiv <= CDNS_UART_BDIV_MAX; bdiv++) {
427 cd = DIV_ROUND_CLOSEST(clk, baud * (bdiv + 1));
428 if (cd < 1 || cd > CDNS_UART_CD_MAX)
429 continue;
430
431 calc_baud = clk / (cd * (bdiv + 1));
432
433 if (baud > calc_baud)
434 bauderror = baud - calc_baud;
435 else
436 bauderror = calc_baud - baud;
437
438 if (besterror > bauderror) {
439 *rbdiv = bdiv;
440 *rcd = cd;
441 bestbaud = calc_baud;
442 besterror = bauderror;
443 }
444 }
445 /* use the values when percent error is acceptable */
446 if (((besterror * 100) / baud) < 3)
447 bestbaud = baud;
448
449 return bestbaud;
450}
451
452/**
453 * cdns_uart_set_baud_rate - Calculate and set the baud rate
454 * @port: Handle to the uart port structure
455 * @baud: Baud rate to set
456 * Return: baud rate, requested baud when possible, or actual baud when there
457 * was too much error, zero if no valid divisors are found.
458 */
459static unsigned int cdns_uart_set_baud_rate(struct uart_port *port,
460 unsigned int baud)
461{
462 unsigned int calc_baud;
463 u32 cd = 0, bdiv = 0;
464 u32 mreg;
465 int div8;
466 struct cdns_uart *cdns_uart = port->private_data;
467
468 calc_baud = cdns_uart_calc_baud_divs(port->uartclk, baud, &bdiv, &cd,
469 &div8);
470
471 /* Write new divisors to hardware */
472 mreg = readl(port->membase + CDNS_UART_MR);
473 if (div8)
474 mreg |= CDNS_UART_MR_CLKSEL;
475 else
476 mreg &= ~CDNS_UART_MR_CLKSEL;
477 writel(mreg, port->membase + CDNS_UART_MR);
478 writel(cd, port->membase + CDNS_UART_BAUDGEN);
479 writel(bdiv, port->membase + CDNS_UART_BAUDDIV);
480 cdns_uart->baud = baud;
481
482 return calc_baud;
483}
484
485#ifdef CONFIG_COMMON_CLK
486/**
487 * cdns_uart_clk_notifier_cb - Clock notifier callback
488 * @nb: Notifier block
489 * @event: Notify event
490 * @data: Notifier data
491 * Return: NOTIFY_OK or NOTIFY_DONE on success, NOTIFY_BAD on error.
492 */
493static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
494 unsigned long event, void *data)
495{
496 u32 ctrl_reg;
497 struct uart_port *port;
498 int locked = 0;
499 struct clk_notifier_data *ndata = data;
500 struct cdns_uart *cdns_uart = to_cdns_uart(nb);
501 unsigned long flags;
502
503 port = cdns_uart->port;
504 if (port->suspended)
505 return NOTIFY_OK;
506
507 switch (event) {
508 case PRE_RATE_CHANGE:
509 {
510 u32 bdiv, cd;
511 int div8;
512
513 /*
514 * Find out if current baud-rate can be achieved with new clock
515 * frequency.
516 */
517 if (!cdns_uart_calc_baud_divs(ndata->new_rate, cdns_uart->baud,
518 &bdiv, &cd, &div8)) {
519 dev_warn(port->dev, "clock rate change rejected\n");
520 return NOTIFY_BAD;
521 }
522
523 spin_lock_irqsave(&cdns_uart->port->lock, flags);
524
525 /* Disable the TX and RX to set baud rate */
526 ctrl_reg = readl(port->membase + CDNS_UART_CR);
527 ctrl_reg |= CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS;
528 writel(ctrl_reg, port->membase + CDNS_UART_CR);
529
530 spin_unlock_irqrestore(&cdns_uart->port->lock, flags);
531
532 return NOTIFY_OK;
533 }
534 case POST_RATE_CHANGE:
535 /*
536 * Set clk dividers to generate correct baud with new clock
537 * frequency.
538 */
539
540 spin_lock_irqsave(&cdns_uart->port->lock, flags);
541
542 locked = 1;
543 port->uartclk = ndata->new_rate;
544
545 cdns_uart->baud = cdns_uart_set_baud_rate(cdns_uart->port,
546 cdns_uart->baud);
547 fallthrough;
548 case ABORT_RATE_CHANGE:
549 if (!locked)
550 spin_lock_irqsave(&cdns_uart->port->lock, flags);
551
552 /* Set TX/RX Reset */
553 ctrl_reg = readl(port->membase + CDNS_UART_CR);
554 ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
555 writel(ctrl_reg, port->membase + CDNS_UART_CR);
556
557 while (readl(port->membase + CDNS_UART_CR) &
558 (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
559 cpu_relax();
560
561 /*
562 * Clear the RX disable and TX disable bits and then set the TX
563 * enable bit and RX enable bit to enable the transmitter and
564 * receiver.
565 */
566 writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
567 ctrl_reg = readl(port->membase + CDNS_UART_CR);
568 ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
569 ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
570 writel(ctrl_reg, port->membase + CDNS_UART_CR);
571
572 spin_unlock_irqrestore(&cdns_uart->port->lock, flags);
573
574 return NOTIFY_OK;
575 default:
576 return NOTIFY_DONE;
577 }
578}
579#endif
580
581/**
582 * cdns_uart_start_tx - Start transmitting bytes
583 * @port: Handle to the uart port structure
584 */
585static void cdns_uart_start_tx(struct uart_port *port)
586{
587 unsigned int status;
588
589 if (uart_tx_stopped(port))
590 return;
591
592 /*
593 * Set the TX enable bit and clear the TX disable bit to enable the
594 * transmitter.
595 */
596 status = readl(port->membase + CDNS_UART_CR);
597 status &= ~CDNS_UART_CR_TX_DIS;
598 status |= CDNS_UART_CR_TX_EN;
599 writel(status, port->membase + CDNS_UART_CR);
600
601 if (uart_circ_empty(&port->state->xmit))
602 return;
603
604 cdns_uart_handle_tx(port);
605
606 writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);
607 /* Enable the TX Empty interrupt */
608 writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IER);
609}
610
611/**
612 * cdns_uart_stop_tx - Stop TX
613 * @port: Handle to the uart port structure
614 */
615static void cdns_uart_stop_tx(struct uart_port *port)
616{
617 unsigned int regval;
618
619 regval = readl(port->membase + CDNS_UART_CR);
620 regval |= CDNS_UART_CR_TX_DIS;
621 /* Disable the transmitter */
622 writel(regval, port->membase + CDNS_UART_CR);
623}
624
625/**
626 * cdns_uart_stop_rx - Stop RX
627 * @port: Handle to the uart port structure
628 */
629static void cdns_uart_stop_rx(struct uart_port *port)
630{
631 unsigned int regval;
632
633 /* Disable RX IRQs */
634 writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IDR);
635
636 /* Disable the receiver */
637 regval = readl(port->membase + CDNS_UART_CR);
638 regval |= CDNS_UART_CR_RX_DIS;
639 writel(regval, port->membase + CDNS_UART_CR);
640}
641
642/**
643 * cdns_uart_tx_empty - Check whether TX is empty
644 * @port: Handle to the uart port structure
645 *
646 * Return: TIOCSER_TEMT on success, 0 otherwise
647 */
648static unsigned int cdns_uart_tx_empty(struct uart_port *port)
649{
650 unsigned int status;
651
652 status = readl(port->membase + CDNS_UART_SR) &
653 (CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE);
654 return (status == CDNS_UART_SR_TXEMPTY) ? TIOCSER_TEMT : 0;
655}
656
657/**
658 * cdns_uart_break_ctl - Based on the input ctl we have to start or stop
659 * transmitting char breaks
660 * @port: Handle to the uart port structure
661 * @ctl: Value based on which start or stop decision is taken
662 */
663static void cdns_uart_break_ctl(struct uart_port *port, int ctl)
664{
665 unsigned int status;
666 unsigned long flags;
667
668 spin_lock_irqsave(&port->lock, flags);
669
670 status = readl(port->membase + CDNS_UART_CR);
671
672 if (ctl == -1)
673 writel(CDNS_UART_CR_STARTBRK | status,
674 port->membase + CDNS_UART_CR);
675 else {
676 if ((status & CDNS_UART_CR_STOPBRK) == 0)
677 writel(CDNS_UART_CR_STOPBRK | status,
678 port->membase + CDNS_UART_CR);
679 }
680 spin_unlock_irqrestore(&port->lock, flags);
681}
682
683/**
684 * cdns_uart_set_termios - termios operations, handling data length, parity,
685 * stop bits, flow control, baud rate
686 * @port: Handle to the uart port structure
687 * @termios: Handle to the input termios structure
688 * @old: Values of the previously saved termios structure
689 */
690static void cdns_uart_set_termios(struct uart_port *port,
691 struct ktermios *termios, struct ktermios *old)
692{
693 u32 cval = 0;
694 unsigned int baud, minbaud, maxbaud;
695 unsigned long flags;
696 unsigned int ctrl_reg, mode_reg;
697
698 spin_lock_irqsave(&port->lock, flags);
699
700 /* Disable the TX and RX to set baud rate */
701 ctrl_reg = readl(port->membase + CDNS_UART_CR);
702 ctrl_reg |= CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS;
703 writel(ctrl_reg, port->membase + CDNS_UART_CR);
704
705 /*
706 * Min baud rate = 6bps and Max Baud Rate is 10Mbps for 100Mhz clk
707 * min and max baud should be calculated here based on port->uartclk.
708 * this way we get a valid baud and can safely call set_baud()
709 */
710 minbaud = port->uartclk /
711 ((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX * 8);
712 maxbaud = port->uartclk / (CDNS_UART_BDIV_MIN + 1);
713 baud = uart_get_baud_rate(port, termios, old, minbaud, maxbaud);
714 baud = cdns_uart_set_baud_rate(port, baud);
715 if (tty_termios_baud_rate(termios))
716 tty_termios_encode_baud_rate(termios, baud, baud);
717
718 /* Update the per-port timeout. */
719 uart_update_timeout(port, termios->c_cflag, baud);
720
721 /* Set TX/RX Reset */
722 ctrl_reg = readl(port->membase + CDNS_UART_CR);
723 ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
724 writel(ctrl_reg, port->membase + CDNS_UART_CR);
725
726 while (readl(port->membase + CDNS_UART_CR) &
727 (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
728 cpu_relax();
729
730 /*
731 * Clear the RX disable and TX disable bits and then set the TX enable
732 * bit and RX enable bit to enable the transmitter and receiver.
733 */
734 ctrl_reg = readl(port->membase + CDNS_UART_CR);
735 ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
736 ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
737 writel(ctrl_reg, port->membase + CDNS_UART_CR);
738
739 writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
740
741 port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |
742 CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_TOUT;
743 port->ignore_status_mask = 0;
744
745 if (termios->c_iflag & INPCK)
746 port->read_status_mask |= CDNS_UART_IXR_PARITY |
747 CDNS_UART_IXR_FRAMING;
748
749 if (termios->c_iflag & IGNPAR)
750 port->ignore_status_mask |= CDNS_UART_IXR_PARITY |
751 CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN;
752
753 /* ignore all characters if CREAD is not set */
754 if ((termios->c_cflag & CREAD) == 0)
755 port->ignore_status_mask |= CDNS_UART_IXR_RXTRIG |
756 CDNS_UART_IXR_TOUT | CDNS_UART_IXR_PARITY |
757 CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN;
758
759 mode_reg = readl(port->membase + CDNS_UART_MR);
760
761 /* Handling Data Size */
762 switch (termios->c_cflag & CSIZE) {
763 case CS6:
764 cval |= CDNS_UART_MR_CHARLEN_6_BIT;
765 break;
766 case CS7:
767 cval |= CDNS_UART_MR_CHARLEN_7_BIT;
768 break;
769 default:
770 case CS8:
771 cval |= CDNS_UART_MR_CHARLEN_8_BIT;
772 termios->c_cflag &= ~CSIZE;
773 termios->c_cflag |= CS8;
774 break;
775 }
776
777 /* Handling Parity and Stop Bits length */
778 if (termios->c_cflag & CSTOPB)
779 cval |= CDNS_UART_MR_STOPMODE_2_BIT; /* 2 STOP bits */
780 else
781 cval |= CDNS_UART_MR_STOPMODE_1_BIT; /* 1 STOP bit */
782
783 if (termios->c_cflag & PARENB) {
784 /* Mark or Space parity */
785 if (termios->c_cflag & CMSPAR) {
786 if (termios->c_cflag & PARODD)
787 cval |= CDNS_UART_MR_PARITY_MARK;
788 else
789 cval |= CDNS_UART_MR_PARITY_SPACE;
790 } else {
791 if (termios->c_cflag & PARODD)
792 cval |= CDNS_UART_MR_PARITY_ODD;
793 else
794 cval |= CDNS_UART_MR_PARITY_EVEN;
795 }
796 } else {
797 cval |= CDNS_UART_MR_PARITY_NONE;
798 }
799 cval |= mode_reg & 1;
800 writel(cval, port->membase + CDNS_UART_MR);
801
802 cval = readl(port->membase + CDNS_UART_MODEMCR);
803 if (termios->c_cflag & CRTSCTS)
804 cval |= CDNS_UART_MODEMCR_FCM;
805 else
806 cval &= ~CDNS_UART_MODEMCR_FCM;
807 writel(cval, port->membase + CDNS_UART_MODEMCR);
808
809 spin_unlock_irqrestore(&port->lock, flags);
810}
811
812/**
813 * cdns_uart_startup - Called when an application opens a cdns_uart port
814 * @port: Handle to the uart port structure
815 *
816 * Return: 0 on success, negative errno otherwise
817 */
818static int cdns_uart_startup(struct uart_port *port)
819{
820 struct cdns_uart *cdns_uart = port->private_data;
821 bool is_brk_support;
822 int ret;
823 unsigned long flags;
824 unsigned int status = 0;
825
826 is_brk_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;
827
828 spin_lock_irqsave(&port->lock, flags);
829
830 /* Disable the TX and RX */
831 writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
832 port->membase + CDNS_UART_CR);
833
834 /* Set the Control Register with TX/RX Enable, TX/RX Reset,
835 * no break chars.
836 */
837 writel(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST,
838 port->membase + CDNS_UART_CR);
839
840 while (readl(port->membase + CDNS_UART_CR) &
841 (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
842 cpu_relax();
843
844 /*
845 * Clear the RX disable bit and then set the RX enable bit to enable
846 * the receiver.
847 */
848 status = readl(port->membase + CDNS_UART_CR);
849 status &= ~CDNS_UART_CR_RX_DIS;
850 status |= CDNS_UART_CR_RX_EN;
851 writel(status, port->membase + CDNS_UART_CR);
852
853 /* Set the Mode Register with normal mode,8 data bits,1 stop bit,
854 * no parity.
855 */
856 writel(CDNS_UART_MR_CHMODE_NORM | CDNS_UART_MR_STOPMODE_1_BIT
857 | CDNS_UART_MR_PARITY_NONE | CDNS_UART_MR_CHARLEN_8_BIT,
858 port->membase + CDNS_UART_MR);
859
860 /*
861 * Set the RX FIFO Trigger level to use most of the FIFO, but it
862 * can be tuned with a module parameter
863 */
864 writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);
865
866 /*
867 * Receive Timeout register is enabled but it
868 * can be tuned with a module parameter
869 */
870 writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
871
872 /* Clear out any pending interrupts before enabling them */
873 writel(readl(port->membase + CDNS_UART_ISR),
874 port->membase + CDNS_UART_ISR);
875
876 spin_unlock_irqrestore(&port->lock, flags);
877
878 ret = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME, port);
879 if (ret) {
880 dev_err(port->dev, "request_irq '%d' failed with %d\n",
881 port->irq, ret);
882 return ret;
883 }
884
885 /* Set the Interrupt Registers with desired interrupts */
886 if (is_brk_support)
887 writel(CDNS_UART_RX_IRQS | CDNS_UART_IXR_BRK,
888 port->membase + CDNS_UART_IER);
889 else
890 writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER);
891
892 return 0;
893}
894
895/**
896 * cdns_uart_shutdown - Called when an application closes a cdns_uart port
897 * @port: Handle to the uart port structure
898 */
899static void cdns_uart_shutdown(struct uart_port *port)
900{
901 int status;
902 unsigned long flags;
903
904 spin_lock_irqsave(&port->lock, flags);
905
906 /* Disable interrupts */
907 status = readl(port->membase + CDNS_UART_IMR);
908 writel(status, port->membase + CDNS_UART_IDR);
909 writel(0xffffffff, port->membase + CDNS_UART_ISR);
910
911 /* Disable the TX and RX */
912 writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
913 port->membase + CDNS_UART_CR);
914
915 spin_unlock_irqrestore(&port->lock, flags);
916
917 free_irq(port->irq, port);
918}
919
920/**
921 * cdns_uart_type - Set UART type to cdns_uart port
922 * @port: Handle to the uart port structure
923 *
924 * Return: string on success, NULL otherwise
925 */
926static const char *cdns_uart_type(struct uart_port *port)
927{
928 return port->type == PORT_XUARTPS ? CDNS_UART_NAME : NULL;
929}
930
931/**
932 * cdns_uart_verify_port - Verify the port params
933 * @port: Handle to the uart port structure
934 * @ser: Handle to the structure whose members are compared
935 *
936 * Return: 0 on success, negative errno otherwise.
937 */
938static int cdns_uart_verify_port(struct uart_port *port,
939 struct serial_struct *ser)
940{
941 if (ser->type != PORT_UNKNOWN && ser->type != PORT_XUARTPS)
942 return -EINVAL;
943 if (port->irq != ser->irq)
944 return -EINVAL;
945 if (ser->io_type != UPIO_MEM)
946 return -EINVAL;
947 if (port->iobase != ser->port)
948 return -EINVAL;
949 if (ser->hub6 != 0)
950 return -EINVAL;
951 return 0;
952}
953
954/**
955 * cdns_uart_request_port - Claim the memory region attached to cdns_uart port,
956 * called when the driver adds a cdns_uart port via
957 * uart_add_one_port()
958 * @port: Handle to the uart port structure
959 *
960 * Return: 0 on success, negative errno otherwise.
961 */
962static int cdns_uart_request_port(struct uart_port *port)
963{
964 if (!request_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE,
965 CDNS_UART_NAME)) {
966 return -ENOMEM;
967 }
968
969 port->membase = ioremap(port->mapbase, CDNS_UART_REGISTER_SPACE);
970 if (!port->membase) {
971 dev_err(port->dev, "Unable to map registers\n");
972 release_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE);
973 return -ENOMEM;
974 }
975 return 0;
976}
977
978/**
979 * cdns_uart_release_port - Release UART port
980 * @port: Handle to the uart port structure
981 *
982 * Release the memory region attached to a cdns_uart port. Called when the
983 * driver removes a cdns_uart port via uart_remove_one_port().
984 */
985static void cdns_uart_release_port(struct uart_port *port)
986{
987 release_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE);
988 iounmap(port->membase);
989 port->membase = NULL;
990}
991
992/**
993 * cdns_uart_config_port - Configure UART port
994 * @port: Handle to the uart port structure
995 * @flags: If any
996 */
997static void cdns_uart_config_port(struct uart_port *port, int flags)
998{
999 if (flags & UART_CONFIG_TYPE && cdns_uart_request_port(port) == 0)
1000 port->type = PORT_XUARTPS;
1001}
1002
1003/**
1004 * cdns_uart_get_mctrl - Get the modem control state
1005 * @port: Handle to the uart port structure
1006 *
1007 * Return: the modem control state
1008 */
1009static unsigned int cdns_uart_get_mctrl(struct uart_port *port)
1010{
1011 u32 val;
1012 unsigned int mctrl = 0;
1013 struct cdns_uart *cdns_uart_data = port->private_data;
1014
1015 if (cdns_uart_data->cts_override)
1016 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
1017
1018 val = readl(port->membase + CDNS_UART_MODEMSR);
1019 if (val & CDNS_UART_MODEMSR_CTS)
1020 mctrl |= TIOCM_CTS;
1021 if (val & CDNS_UART_MODEMSR_DSR)
1022 mctrl |= TIOCM_DSR;
1023 if (val & CDNS_UART_MODEMSR_RI)
1024 mctrl |= TIOCM_RNG;
1025 if (val & CDNS_UART_MODEMSR_DCD)
1026 mctrl |= TIOCM_CAR;
1027
1028 return mctrl;
1029}
1030
1031static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
1032{
1033 u32 val;
1034 u32 mode_reg;
1035 struct cdns_uart *cdns_uart_data = port->private_data;
1036
1037 if (cdns_uart_data->cts_override)
1038 return;
1039
1040 val = readl(port->membase + CDNS_UART_MODEMCR);
1041 mode_reg = readl(port->membase + CDNS_UART_MR);
1042
1043 val &= ~(CDNS_UART_MODEMCR_RTS | CDNS_UART_MODEMCR_DTR);
1044 mode_reg &= ~CDNS_UART_MR_CHMODE_MASK;
1045
1046 if (mctrl & TIOCM_RTS)
1047 val |= CDNS_UART_MODEMCR_RTS;
1048 if (mctrl & TIOCM_DTR)
1049 val |= CDNS_UART_MODEMCR_DTR;
1050 if (mctrl & TIOCM_LOOP)
1051 mode_reg |= CDNS_UART_MR_CHMODE_L_LOOP;
1052 else
1053 mode_reg |= CDNS_UART_MR_CHMODE_NORM;
1054
1055 writel(val, port->membase + CDNS_UART_MODEMCR);
1056 writel(mode_reg, port->membase + CDNS_UART_MR);
1057}
1058
1059#ifdef CONFIG_CONSOLE_POLL
1060static int cdns_uart_poll_get_char(struct uart_port *port)
1061{
1062 int c;
1063 unsigned long flags;
1064
1065 spin_lock_irqsave(&port->lock, flags);
1066
1067 /* Check if FIFO is empty */
1068 if (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_RXEMPTY)
1069 c = NO_POLL_CHAR;
1070 else /* Read a character */
1071 c = (unsigned char) readl(port->membase + CDNS_UART_FIFO);
1072
1073 spin_unlock_irqrestore(&port->lock, flags);
1074
1075 return c;
1076}
1077
1078static void cdns_uart_poll_put_char(struct uart_port *port, unsigned char c)
1079{
1080 unsigned long flags;
1081
1082 spin_lock_irqsave(&port->lock, flags);
1083
1084 /* Wait until FIFO is empty */
1085 while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))
1086 cpu_relax();
1087
1088 /* Write a character */
1089 writel(c, port->membase + CDNS_UART_FIFO);
1090
1091 /* Wait until FIFO is empty */
1092 while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))
1093 cpu_relax();
1094
1095 spin_unlock_irqrestore(&port->lock, flags);
1096}
1097#endif
1098
1099static void cdns_uart_pm(struct uart_port *port, unsigned int state,
1100 unsigned int oldstate)
1101{
1102 switch (state) {
1103 case UART_PM_STATE_OFF:
1104 pm_runtime_mark_last_busy(port->dev);
1105 pm_runtime_put_autosuspend(port->dev);
1106 break;
1107 default:
1108 pm_runtime_get_sync(port->dev);
1109 break;
1110 }
1111}
1112
1113static const struct uart_ops cdns_uart_ops = {
1114 .set_mctrl = cdns_uart_set_mctrl,
1115 .get_mctrl = cdns_uart_get_mctrl,
1116 .start_tx = cdns_uart_start_tx,
1117 .stop_tx = cdns_uart_stop_tx,
1118 .stop_rx = cdns_uart_stop_rx,
1119 .tx_empty = cdns_uart_tx_empty,
1120 .break_ctl = cdns_uart_break_ctl,
1121 .set_termios = cdns_uart_set_termios,
1122 .startup = cdns_uart_startup,
1123 .shutdown = cdns_uart_shutdown,
1124 .pm = cdns_uart_pm,
1125 .type = cdns_uart_type,
1126 .verify_port = cdns_uart_verify_port,
1127 .request_port = cdns_uart_request_port,
1128 .release_port = cdns_uart_release_port,
1129 .config_port = cdns_uart_config_port,
1130#ifdef CONFIG_CONSOLE_POLL
1131 .poll_get_char = cdns_uart_poll_get_char,
1132 .poll_put_char = cdns_uart_poll_put_char,
1133#endif
1134};
1135
1136static struct uart_driver cdns_uart_uart_driver;
1137
1138#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1139/**
1140 * cdns_uart_console_putchar - write the character to the FIFO buffer
1141 * @port: Handle to the uart port structure
1142 * @ch: Character to be written
1143 */
1144static void cdns_uart_console_putchar(struct uart_port *port, int ch)
1145{
1146 while (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)
1147 cpu_relax();
1148 writel(ch, port->membase + CDNS_UART_FIFO);
1149}
1150
1151static void cdns_early_write(struct console *con, const char *s,
1152 unsigned int n)
1153{
1154 struct earlycon_device *dev = con->data;
1155
1156 uart_console_write(&dev->port, s, n, cdns_uart_console_putchar);
1157}
1158
1159static int __init cdns_early_console_setup(struct earlycon_device *device,
1160 const char *opt)
1161{
1162 struct uart_port *port = &device->port;
1163
1164 if (!port->membase)
1165 return -ENODEV;
1166
1167 /* initialise control register */
1168 writel(CDNS_UART_CR_TX_EN|CDNS_UART_CR_TXRST|CDNS_UART_CR_RXRST,
1169 port->membase + CDNS_UART_CR);
1170
1171 /* only set baud if specified on command line - otherwise
1172 * assume it has been initialized by a boot loader.
1173 */
1174 if (port->uartclk && device->baud) {
1175 u32 cd = 0, bdiv = 0;
1176 u32 mr;
1177 int div8;
1178
1179 cdns_uart_calc_baud_divs(port->uartclk, device->baud,
1180 &bdiv, &cd, &div8);
1181 mr = CDNS_UART_MR_PARITY_NONE;
1182 if (div8)
1183 mr |= CDNS_UART_MR_CLKSEL;
1184
1185 writel(mr, port->membase + CDNS_UART_MR);
1186 writel(cd, port->membase + CDNS_UART_BAUDGEN);
1187 writel(bdiv, port->membase + CDNS_UART_BAUDDIV);
1188 }
1189
1190 device->con->write = cdns_early_write;
1191
1192 return 0;
1193}
1194OF_EARLYCON_DECLARE(cdns, "xlnx,xuartps", cdns_early_console_setup);
1195OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p8", cdns_early_console_setup);
1196OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p12", cdns_early_console_setup);
1197OF_EARLYCON_DECLARE(cdns, "xlnx,zynqmp-uart", cdns_early_console_setup);
1198
1199
1200/* Static pointer to console port */
1201static struct uart_port *console_port;
1202
1203/**
1204 * cdns_uart_console_write - perform write operation
1205 * @co: Console handle
1206 * @s: Pointer to character array
1207 * @count: No of characters
1208 */
1209static void cdns_uart_console_write(struct console *co, const char *s,
1210 unsigned int count)
1211{
1212 struct uart_port *port = console_port;
1213 unsigned long flags;
1214 unsigned int imr, ctrl;
1215 int locked = 1;
1216
1217 if (port->sysrq)
1218 locked = 0;
1219 else if (oops_in_progress)
1220 locked = spin_trylock_irqsave(&port->lock, flags);
1221 else
1222 spin_lock_irqsave(&port->lock, flags);
1223
1224 /* save and disable interrupt */
1225 imr = readl(port->membase + CDNS_UART_IMR);
1226 writel(imr, port->membase + CDNS_UART_IDR);
1227
1228 /*
1229 * Make sure that the tx part is enabled. Set the TX enable bit and
1230 * clear the TX disable bit to enable the transmitter.
1231 */
1232 ctrl = readl(port->membase + CDNS_UART_CR);
1233 ctrl &= ~CDNS_UART_CR_TX_DIS;
1234 ctrl |= CDNS_UART_CR_TX_EN;
1235 writel(ctrl, port->membase + CDNS_UART_CR);
1236
1237 uart_console_write(port, s, count, cdns_uart_console_putchar);
1238 while (cdns_uart_tx_empty(port) != TIOCSER_TEMT)
1239 cpu_relax();
1240
1241 /* restore interrupt state */
1242 writel(imr, port->membase + CDNS_UART_IER);
1243
1244 if (locked)
1245 spin_unlock_irqrestore(&port->lock, flags);
1246}
1247
1248/**
1249 * cdns_uart_console_setup - Initialize the uart to default config
1250 * @co: Console handle
1251 * @options: Initial settings of uart
1252 *
1253 * Return: 0 on success, negative errno otherwise.
1254 */
1255static int cdns_uart_console_setup(struct console *co, char *options)
1256{
1257 struct uart_port *port = console_port;
1258
1259 int baud = 9600;
1260 int bits = 8;
1261 int parity = 'n';
1262 int flow = 'n';
1263 unsigned long time_out;
1264
1265 if (!port->membase) {
1266 pr_debug("console on " CDNS_UART_TTY_NAME "%i not present\n",
1267 co->index);
1268 return -ENODEV;
1269 }
1270
1271 if (options)
1272 uart_parse_options(options, &baud, &parity, &bits, &flow);
1273
1274 /* Wait for tx_empty before setting up the console */
1275 time_out = jiffies + usecs_to_jiffies(TX_TIMEOUT);
1276
1277 while (time_before(jiffies, time_out) &&
1278 cdns_uart_tx_empty(port) != TIOCSER_TEMT)
1279 cpu_relax();
1280
1281 return uart_set_options(port, co, baud, parity, bits, flow);
1282}
1283
1284static struct console cdns_uart_console = {
1285 .name = CDNS_UART_TTY_NAME,
1286 .write = cdns_uart_console_write,
1287 .device = uart_console_device,
1288 .setup = cdns_uart_console_setup,
1289 .flags = CON_PRINTBUFFER,
1290 .index = -1, /* Specified on the cmdline (e.g. console=ttyPS ) */
1291 .data = &cdns_uart_uart_driver,
1292};
1293#endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */
1294
1295#ifdef CONFIG_PM_SLEEP
1296/**
1297 * cdns_uart_suspend - suspend event
1298 * @device: Pointer to the device structure
1299 *
1300 * Return: 0
1301 */
1302static int cdns_uart_suspend(struct device *device)
1303{
1304 struct uart_port *port = dev_get_drvdata(device);
1305 struct cdns_uart *cdns_uart = port->private_data;
1306 int may_wake;
1307
1308 may_wake = device_may_wakeup(device);
1309
1310 if (console_suspend_enabled && uart_console(port) && may_wake) {
1311 unsigned long flags;
1312
1313 spin_lock_irqsave(&port->lock, flags);
1314 /* Empty the receive FIFO 1st before making changes */
1315 while (!(readl(port->membase + CDNS_UART_SR) &
1316 CDNS_UART_SR_RXEMPTY))
1317 readl(port->membase + CDNS_UART_FIFO);
1318 /* set RX trigger level to 1 */
1319 writel(1, port->membase + CDNS_UART_RXWM);
1320 /* disable RX timeout interrups */
1321 writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IDR);
1322 spin_unlock_irqrestore(&port->lock, flags);
1323 }
1324
1325 /*
1326 * Call the API provided in serial_core.c file which handles
1327 * the suspend.
1328 */
1329 return uart_suspend_port(cdns_uart->cdns_uart_driver, port);
1330}
1331
1332/**
1333 * cdns_uart_resume - Resume after a previous suspend
1334 * @device: Pointer to the device structure
1335 *
1336 * Return: 0
1337 */
1338static int cdns_uart_resume(struct device *device)
1339{
1340 struct uart_port *port = dev_get_drvdata(device);
1341 struct cdns_uart *cdns_uart = port->private_data;
1342 unsigned long flags;
1343 u32 ctrl_reg;
1344 int may_wake;
1345
1346 may_wake = device_may_wakeup(device);
1347
1348 if (console_suspend_enabled && uart_console(port) && !may_wake) {
1349 clk_enable(cdns_uart->pclk);
1350 clk_enable(cdns_uart->uartclk);
1351
1352 spin_lock_irqsave(&port->lock, flags);
1353
1354 /* Set TX/RX Reset */
1355 ctrl_reg = readl(port->membase + CDNS_UART_CR);
1356 ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
1357 writel(ctrl_reg, port->membase + CDNS_UART_CR);
1358 while (readl(port->membase + CDNS_UART_CR) &
1359 (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
1360 cpu_relax();
1361
1362 /* restore rx timeout value */
1363 writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
1364 /* Enable Tx/Rx */
1365 ctrl_reg = readl(port->membase + CDNS_UART_CR);
1366 ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
1367 ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
1368 writel(ctrl_reg, port->membase + CDNS_UART_CR);
1369
1370 clk_disable(cdns_uart->uartclk);
1371 clk_disable(cdns_uart->pclk);
1372 spin_unlock_irqrestore(&port->lock, flags);
1373 } else {
1374 spin_lock_irqsave(&port->lock, flags);
1375 /* restore original rx trigger level */
1376 writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);
1377 /* enable RX timeout interrupt */
1378 writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IER);
1379 spin_unlock_irqrestore(&port->lock, flags);
1380 }
1381
1382 return uart_resume_port(cdns_uart->cdns_uart_driver, port);
1383}
1384#endif /* ! CONFIG_PM_SLEEP */
1385static int __maybe_unused cdns_runtime_suspend(struct device *dev)
1386{
1387 struct uart_port *port = dev_get_drvdata(dev);
1388 struct cdns_uart *cdns_uart = port->private_data;
1389
1390 clk_disable(cdns_uart->uartclk);
1391 clk_disable(cdns_uart->pclk);
1392 return 0;
1393};
1394
1395static int __maybe_unused cdns_runtime_resume(struct device *dev)
1396{
1397 struct uart_port *port = dev_get_drvdata(dev);
1398 struct cdns_uart *cdns_uart = port->private_data;
1399
1400 clk_enable(cdns_uart->pclk);
1401 clk_enable(cdns_uart->uartclk);
1402 return 0;
1403};
1404
1405static const struct dev_pm_ops cdns_uart_dev_pm_ops = {
1406 SET_SYSTEM_SLEEP_PM_OPS(cdns_uart_suspend, cdns_uart_resume)
1407 SET_RUNTIME_PM_OPS(cdns_runtime_suspend,
1408 cdns_runtime_resume, NULL)
1409};
1410
1411static const struct cdns_platform_data zynqmp_uart_def = {
1412 .quirks = CDNS_UART_RXBS_SUPPORT, };
1413
1414/* Match table for of_platform binding */
1415static const struct of_device_id cdns_uart_of_match[] = {
1416 { .compatible = "xlnx,xuartps", },
1417 { .compatible = "cdns,uart-r1p8", },
1418 { .compatible = "cdns,uart-r1p12", .data = &zynqmp_uart_def },
1419 { .compatible = "xlnx,zynqmp-uart", .data = &zynqmp_uart_def },
1420 {}
1421};
1422MODULE_DEVICE_TABLE(of, cdns_uart_of_match);
1423
1424/* Temporary variable for storing number of instances */
1425static int instances;
1426
1427/**
1428 * cdns_uart_probe - Platform driver probe
1429 * @pdev: Pointer to the platform device structure
1430 *
1431 * Return: 0 on success, negative errno otherwise
1432 */
1433static int cdns_uart_probe(struct platform_device *pdev)
1434{
1435 int rc, id, irq;
1436 struct uart_port *port;
1437 struct resource *res;
1438 struct cdns_uart *cdns_uart_data;
1439 const struct of_device_id *match;
1440
1441 cdns_uart_data = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_data),
1442 GFP_KERNEL);
1443 if (!cdns_uart_data)
1444 return -ENOMEM;
1445 port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
1446 if (!port)
1447 return -ENOMEM;
1448
1449 /* Look for a serialN alias */
1450 id = of_alias_get_id(pdev->dev.of_node, "serial");
1451 if (id < 0)
1452 id = 0;
1453
1454 if (id >= CDNS_UART_NR_PORTS) {
1455 dev_err(&pdev->dev, "Cannot get uart_port structure\n");
1456 return -ENODEV;
1457 }
1458
1459 if (!cdns_uart_uart_driver.state) {
1460 cdns_uart_uart_driver.owner = THIS_MODULE;
1461 cdns_uart_uart_driver.driver_name = CDNS_UART_NAME;
1462 cdns_uart_uart_driver.dev_name = CDNS_UART_TTY_NAME;
1463 cdns_uart_uart_driver.major = CDNS_UART_MAJOR;
1464 cdns_uart_uart_driver.minor = CDNS_UART_MINOR;
1465 cdns_uart_uart_driver.nr = CDNS_UART_NR_PORTS;
1466#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1467 cdns_uart_uart_driver.cons = &cdns_uart_console;
1468#endif
1469
1470 rc = uart_register_driver(&cdns_uart_uart_driver);
1471 if (rc < 0) {
1472 dev_err(&pdev->dev, "Failed to register driver\n");
1473 return rc;
1474 }
1475 }
1476
1477 cdns_uart_data->cdns_uart_driver = &cdns_uart_uart_driver;
1478
1479 match = of_match_node(cdns_uart_of_match, pdev->dev.of_node);
1480 if (match && match->data) {
1481 const struct cdns_platform_data *data = match->data;
1482
1483 cdns_uart_data->quirks = data->quirks;
1484 }
1485
1486 cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "pclk");
1487 if (PTR_ERR(cdns_uart_data->pclk) == -EPROBE_DEFER) {
1488 rc = PTR_ERR(cdns_uart_data->pclk);
1489 goto err_out_unregister_driver;
1490 }
1491
1492 if (IS_ERR(cdns_uart_data->pclk)) {
1493 cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "aper_clk");
1494 if (IS_ERR(cdns_uart_data->pclk)) {
1495 rc = PTR_ERR(cdns_uart_data->pclk);
1496 goto err_out_unregister_driver;
1497 }
1498 dev_err(&pdev->dev, "clock name 'aper_clk' is deprecated.\n");
1499 }
1500
1501 cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");
1502 if (PTR_ERR(cdns_uart_data->uartclk) == -EPROBE_DEFER) {
1503 rc = PTR_ERR(cdns_uart_data->uartclk);
1504 goto err_out_unregister_driver;
1505 }
1506
1507 if (IS_ERR(cdns_uart_data->uartclk)) {
1508 cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "ref_clk");
1509 if (IS_ERR(cdns_uart_data->uartclk)) {
1510 rc = PTR_ERR(cdns_uart_data->uartclk);
1511 goto err_out_unregister_driver;
1512 }
1513 dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n");
1514 }
1515
1516 rc = clk_prepare_enable(cdns_uart_data->pclk);
1517 if (rc) {
1518 dev_err(&pdev->dev, "Unable to enable pclk clock.\n");
1519 goto err_out_unregister_driver;
1520 }
1521 rc = clk_prepare_enable(cdns_uart_data->uartclk);
1522 if (rc) {
1523 dev_err(&pdev->dev, "Unable to enable device clock.\n");
1524 goto err_out_clk_dis_pclk;
1525 }
1526
1527 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1528 if (!res) {
1529 rc = -ENODEV;
1530 goto err_out_clk_disable;
1531 }
1532
1533 irq = platform_get_irq(pdev, 0);
1534 if (irq <= 0) {
1535 rc = -ENXIO;
1536 goto err_out_clk_disable;
1537 }
1538
1539#ifdef CONFIG_COMMON_CLK
1540 cdns_uart_data->clk_rate_change_nb.notifier_call =
1541 cdns_uart_clk_notifier_cb;
1542 if (clk_notifier_register(cdns_uart_data->uartclk,
1543 &cdns_uart_data->clk_rate_change_nb))
1544 dev_warn(&pdev->dev, "Unable to register clock notifier.\n");
1545#endif
1546
1547 /* At this point, we've got an empty uart_port struct, initialize it */
1548 spin_lock_init(&port->lock);
1549 port->type = PORT_UNKNOWN;
1550 port->iotype = UPIO_MEM32;
1551 port->flags = UPF_BOOT_AUTOCONF;
1552 port->ops = &cdns_uart_ops;
1553 port->fifosize = CDNS_UART_FIFO_SIZE;
1554 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_XILINX_PS_UART_CONSOLE);
1555 port->line = id;
1556
1557 /*
1558 * Register the port.
1559 * This function also registers this device with the tty layer
1560 * and triggers invocation of the config_port() entry point.
1561 */
1562 port->mapbase = res->start;
1563 port->irq = irq;
1564 port->dev = &pdev->dev;
1565 port->uartclk = clk_get_rate(cdns_uart_data->uartclk);
1566 port->private_data = cdns_uart_data;
1567 cdns_uart_data->port = port;
1568 platform_set_drvdata(pdev, port);
1569
1570 pm_runtime_use_autosuspend(&pdev->dev);
1571 pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
1572 pm_runtime_set_active(&pdev->dev);
1573 pm_runtime_enable(&pdev->dev);
1574 device_init_wakeup(port->dev, true);
1575
1576#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1577 /*
1578 * If console hasn't been found yet try to assign this port
1579 * because it is required to be assigned for console setup function.
1580 * If register_console() don't assign value, then console_port pointer
1581 * is cleanup.
1582 */
1583 if (!console_port) {
1584 cdns_uart_console.index = id;
1585 console_port = port;
1586 }
1587#endif
1588
1589 rc = uart_add_one_port(&cdns_uart_uart_driver, port);
1590 if (rc) {
1591 dev_err(&pdev->dev,
1592 "uart_add_one_port() failed; err=%i\n", rc);
1593 goto err_out_pm_disable;
1594 }
1595
1596#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1597 /* This is not port which is used for console that's why clean it up */
1598 if (console_port == port &&
1599 !(cdns_uart_uart_driver.cons->flags & CON_ENABLED)) {
1600 console_port = NULL;
1601 cdns_uart_console.index = -1;
1602 }
1603#endif
1604
1605 cdns_uart_data->cts_override = of_property_read_bool(pdev->dev.of_node,
1606 "cts-override");
1607
1608 instances++;
1609
1610 return 0;
1611
1612err_out_pm_disable:
1613 pm_runtime_disable(&pdev->dev);
1614 pm_runtime_set_suspended(&pdev->dev);
1615 pm_runtime_dont_use_autosuspend(&pdev->dev);
1616#ifdef CONFIG_COMMON_CLK
1617 clk_notifier_unregister(cdns_uart_data->uartclk,
1618 &cdns_uart_data->clk_rate_change_nb);
1619#endif
1620err_out_clk_disable:
1621 clk_disable_unprepare(cdns_uart_data->uartclk);
1622err_out_clk_dis_pclk:
1623 clk_disable_unprepare(cdns_uart_data->pclk);
1624err_out_unregister_driver:
1625 if (!instances)
1626 uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
1627 return rc;
1628}
1629
1630/**
1631 * cdns_uart_remove - called when the platform driver is unregistered
1632 * @pdev: Pointer to the platform device structure
1633 *
1634 * Return: 0 on success, negative errno otherwise
1635 */
1636static int cdns_uart_remove(struct platform_device *pdev)
1637{
1638 struct uart_port *port = platform_get_drvdata(pdev);
1639 struct cdns_uart *cdns_uart_data = port->private_data;
1640 int rc;
1641
1642 /* Remove the cdns_uart port from the serial core */
1643#ifdef CONFIG_COMMON_CLK
1644 clk_notifier_unregister(cdns_uart_data->uartclk,
1645 &cdns_uart_data->clk_rate_change_nb);
1646#endif
1647 rc = uart_remove_one_port(cdns_uart_data->cdns_uart_driver, port);
1648 port->mapbase = 0;
1649 clk_disable_unprepare(cdns_uart_data->uartclk);
1650 clk_disable_unprepare(cdns_uart_data->pclk);
1651 pm_runtime_disable(&pdev->dev);
1652 pm_runtime_set_suspended(&pdev->dev);
1653 pm_runtime_dont_use_autosuspend(&pdev->dev);
1654 device_init_wakeup(&pdev->dev, false);
1655
1656#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
1657 if (console_port == port)
1658 console_port = NULL;
1659#endif
1660
1661 if (!--instances)
1662 uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
1663 return rc;
1664}
1665
1666static struct platform_driver cdns_uart_platform_driver = {
1667 .probe = cdns_uart_probe,
1668 .remove = cdns_uart_remove,
1669 .driver = {
1670 .name = CDNS_UART_NAME,
1671 .of_match_table = cdns_uart_of_match,
1672 .pm = &cdns_uart_dev_pm_ops,
1673 .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_XILINX_PS_UART),
1674 },
1675};
1676
1677static int __init cdns_uart_init(void)
1678{
1679 /* Register the platform driver */
1680 return platform_driver_register(&cdns_uart_platform_driver);
1681}
1682
1683static void __exit cdns_uart_exit(void)
1684{
1685 /* Unregister the platform driver */
1686 platform_driver_unregister(&cdns_uart_platform_driver);
1687}
1688
1689arch_initcall(cdns_uart_init);
1690module_exit(cdns_uart_exit);
1691
1692MODULE_DESCRIPTION("Driver for Cadence UART");
1693MODULE_AUTHOR("Xilinx Inc.");
1694MODULE_LICENSE("GPL");