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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * SC16IS7xx tty serial driver - common code
4 *
5 * Copyright (C) 2014 GridPoint
6 * Author: Jon Ringle <jringle@gridpoint.com>
7 * Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
8 */
9
10#undef DEFAULT_SYMBOL_NAMESPACE
11#define DEFAULT_SYMBOL_NAMESPACE "SERIAL_NXP_SC16IS7XX"
12
13#include <linux/bits.h>
14#include <linux/clk.h>
15#include <linux/delay.h>
16#include <linux/device.h>
17#include <linux/export.h>
18#include <linux/gpio/consumer.h>
19#include <linux/gpio/driver.h>
20#include <linux/idr.h>
21#include <linux/kthread.h>
22#include <linux/mod_devicetable.h>
23#include <linux/module.h>
24#include <linux/property.h>
25#include <linux/regmap.h>
26#include <linux/sched.h>
27#include <linux/serial_core.h>
28#include <linux/serial.h>
29#include <linux/string.h>
30#include <linux/tty.h>
31#include <linux/tty_flip.h>
32#include <linux/uaccess.h>
33#include <linux/units.h>
34
35#include "sc16is7xx.h"
36
37#define SC16IS7XX_MAX_DEVS 8
38
39/* SC16IS7XX register definitions */
40#define SC16IS7XX_RHR_REG (0x00) /* RX FIFO */
41#define SC16IS7XX_THR_REG (0x00) /* TX FIFO */
42#define SC16IS7XX_IER_REG (0x01) /* Interrupt enable */
43#define SC16IS7XX_IIR_REG (0x02) /* Interrupt Identification */
44#define SC16IS7XX_FCR_REG (0x02) /* FIFO control */
45#define SC16IS7XX_LCR_REG (0x03) /* Line Control */
46#define SC16IS7XX_MCR_REG (0x04) /* Modem Control */
47#define SC16IS7XX_LSR_REG (0x05) /* Line Status */
48#define SC16IS7XX_MSR_REG (0x06) /* Modem Status */
49#define SC16IS7XX_SPR_REG (0x07) /* Scratch Pad */
50#define SC16IS7XX_TXLVL_REG (0x08) /* TX FIFO level */
51#define SC16IS7XX_RXLVL_REG (0x09) /* RX FIFO level */
52#define SC16IS7XX_IODIR_REG (0x0a) /* I/O Direction
53 * - only on 75x/76x
54 */
55#define SC16IS7XX_IOSTATE_REG (0x0b) /* I/O State
56 * - only on 75x/76x
57 */
58#define SC16IS7XX_IOINTENA_REG (0x0c) /* I/O Interrupt Enable
59 * - only on 75x/76x
60 */
61#define SC16IS7XX_IOCONTROL_REG (0x0e) /* I/O Control
62 * - only on 75x/76x
63 */
64#define SC16IS7XX_EFCR_REG (0x0f) /* Extra Features Control */
65
66/* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
67#define SC16IS7XX_TCR_REG (0x06) /* Transmit control */
68#define SC16IS7XX_TLR_REG (0x07) /* Trigger level */
69
70/* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
71#define SC16IS7XX_DLL_REG (0x00) /* Divisor Latch Low */
72#define SC16IS7XX_DLH_REG (0x01) /* Divisor Latch High */
73
74/* Enhanced Register set: Only if (LCR == 0xBF) */
75#define SC16IS7XX_EFR_REG (0x02) /* Enhanced Features */
76#define SC16IS7XX_XON1_REG (0x04) /* Xon1 word */
77#define SC16IS7XX_XON2_REG (0x05) /* Xon2 word */
78#define SC16IS7XX_XOFF1_REG (0x06) /* Xoff1 word */
79#define SC16IS7XX_XOFF2_REG (0x07) /* Xoff2 word */
80
81/* IER register bits */
82#define SC16IS7XX_IER_RDI_BIT BIT(0) /* Enable RX data interrupt */
83#define SC16IS7XX_IER_THRI_BIT BIT(1) /* Enable TX holding register
84 * interrupt */
85#define SC16IS7XX_IER_RLSI_BIT BIT(2) /* Enable RX line status
86 * interrupt */
87#define SC16IS7XX_IER_MSI_BIT BIT(3) /* Enable Modem status
88 * interrupt */
89
90/* IER register bits - write only if (EFR[4] == 1) */
91#define SC16IS7XX_IER_SLEEP_BIT BIT(4) /* Enable Sleep mode */
92#define SC16IS7XX_IER_XOFFI_BIT BIT(5) /* Enable Xoff interrupt */
93#define SC16IS7XX_IER_RTSI_BIT BIT(6) /* Enable nRTS interrupt */
94#define SC16IS7XX_IER_CTSI_BIT BIT(7) /* Enable nCTS interrupt */
95
96/* FCR register bits */
97#define SC16IS7XX_FCR_FIFO_BIT BIT(0) /* Enable FIFO */
98#define SC16IS7XX_FCR_RXRESET_BIT BIT(1) /* Reset RX FIFO */
99#define SC16IS7XX_FCR_TXRESET_BIT BIT(2) /* Reset TX FIFO */
100#define SC16IS7XX_FCR_RXLVLL_BIT BIT(6) /* RX Trigger level LSB */
101#define SC16IS7XX_FCR_RXLVLH_BIT BIT(7) /* RX Trigger level MSB */
102
103/* FCR register bits - write only if (EFR[4] == 1) */
104#define SC16IS7XX_FCR_TXLVLL_BIT BIT(4) /* TX Trigger level LSB */
105#define SC16IS7XX_FCR_TXLVLH_BIT BIT(5) /* TX Trigger level MSB */
106
107/* IIR register bits */
108#define SC16IS7XX_IIR_NO_INT_BIT 0x01 /* No interrupts pending */
109#define SC16IS7XX_IIR_ID_MASK GENMASK(5, 1) /* Mask for the interrupt ID */
110#define SC16IS7XX_IIR_THRI_SRC 0x02 /* TX holding register empty */
111#define SC16IS7XX_IIR_RDI_SRC 0x04 /* RX data interrupt */
112#define SC16IS7XX_IIR_RLSE_SRC 0x06 /* RX line status error */
113#define SC16IS7XX_IIR_RTOI_SRC 0x0c /* RX time-out interrupt */
114#define SC16IS7XX_IIR_MSI_SRC 0x00 /* Modem status interrupt
115 * - only on 75x/76x
116 */
117#define SC16IS7XX_IIR_INPIN_SRC 0x30 /* Input pin change of state
118 * - only on 75x/76x
119 */
120#define SC16IS7XX_IIR_XOFFI_SRC 0x10 /* Received Xoff */
121#define SC16IS7XX_IIR_CTSRTS_SRC 0x20 /* nCTS,nRTS change of state
122 * from active (LOW)
123 * to inactive (HIGH)
124 */
125/* LCR register bits */
126#define SC16IS7XX_LCR_LENGTH0_BIT BIT(0) /* Word length bit 0 */
127#define SC16IS7XX_LCR_LENGTH1_BIT BIT(1) /* Word length bit 1
128 *
129 * Word length bits table:
130 * 00 -> 5 bit words
131 * 01 -> 6 bit words
132 * 10 -> 7 bit words
133 * 11 -> 8 bit words
134 */
135#define SC16IS7XX_LCR_STOPLEN_BIT BIT(2) /* STOP length bit
136 *
137 * STOP length bit table:
138 * 0 -> 1 stop bit
139 * 1 -> 1-1.5 stop bits if
140 * word length is 5,
141 * 2 stop bits otherwise
142 */
143#define SC16IS7XX_LCR_PARITY_BIT BIT(3) /* Parity bit enable */
144#define SC16IS7XX_LCR_EVENPARITY_BIT BIT(4) /* Even parity bit enable */
145#define SC16IS7XX_LCR_FORCEPARITY_BIT BIT(5) /* 9-bit multidrop parity */
146#define SC16IS7XX_LCR_TXBREAK_BIT BIT(6) /* TX break enable */
147#define SC16IS7XX_LCR_DLAB_BIT BIT(7) /* Divisor Latch enable */
148#define SC16IS7XX_LCR_WORD_LEN_5 (0x00)
149#define SC16IS7XX_LCR_WORD_LEN_6 (0x01)
150#define SC16IS7XX_LCR_WORD_LEN_7 (0x02)
151#define SC16IS7XX_LCR_WORD_LEN_8 (0x03)
152#define SC16IS7XX_LCR_CONF_MODE_A SC16IS7XX_LCR_DLAB_BIT /* Special
153 * reg set */
154#define SC16IS7XX_LCR_CONF_MODE_B 0xBF /* Enhanced
155 * reg set */
156
157/* MCR register bits */
158#define SC16IS7XX_MCR_DTR_BIT BIT(0) /* DTR complement
159 * - only on 75x/76x
160 */
161#define SC16IS7XX_MCR_RTS_BIT BIT(1) /* RTS complement */
162#define SC16IS7XX_MCR_TCRTLR_BIT BIT(2) /* TCR/TLR register enable */
163#define SC16IS7XX_MCR_LOOP_BIT BIT(4) /* Enable loopback test mode */
164#define SC16IS7XX_MCR_XONANY_BIT BIT(5) /* Enable Xon Any
165 * - write enabled
166 * if (EFR[4] == 1)
167 */
168#define SC16IS7XX_MCR_IRDA_BIT BIT(6) /* Enable IrDA mode
169 * - write enabled
170 * if (EFR[4] == 1)
171 */
172#define SC16IS7XX_MCR_CLKSEL_BIT BIT(7) /* Divide clock by 4
173 * - write enabled
174 * if (EFR[4] == 1)
175 */
176
177/* LSR register bits */
178#define SC16IS7XX_LSR_DR_BIT BIT(0) /* Receiver data ready */
179#define SC16IS7XX_LSR_OE_BIT BIT(1) /* Overrun Error */
180#define SC16IS7XX_LSR_PE_BIT BIT(2) /* Parity Error */
181#define SC16IS7XX_LSR_FE_BIT BIT(3) /* Frame Error */
182#define SC16IS7XX_LSR_BI_BIT BIT(4) /* Break Interrupt */
183#define SC16IS7XX_LSR_BRK_ERROR_MASK \
184 (SC16IS7XX_LSR_OE_BIT | \
185 SC16IS7XX_LSR_PE_BIT | \
186 SC16IS7XX_LSR_FE_BIT | \
187 SC16IS7XX_LSR_BI_BIT)
188
189#define SC16IS7XX_LSR_THRE_BIT BIT(5) /* TX holding register empty */
190#define SC16IS7XX_LSR_TEMT_BIT BIT(6) /* Transmitter empty */
191#define SC16IS7XX_LSR_FIFOE_BIT BIT(7) /* Fifo Error */
192
193/* MSR register bits */
194#define SC16IS7XX_MSR_DCTS_BIT BIT(0) /* Delta CTS Clear To Send */
195#define SC16IS7XX_MSR_DDSR_BIT BIT(1) /* Delta DSR Data Set Ready
196 * or (IO4)
197 * - only on 75x/76x
198 */
199#define SC16IS7XX_MSR_DRI_BIT BIT(2) /* Delta RI Ring Indicator
200 * or (IO7)
201 * - only on 75x/76x
202 */
203#define SC16IS7XX_MSR_DCD_BIT BIT(3) /* Delta CD Carrier Detect
204 * or (IO6)
205 * - only on 75x/76x
206 */
207#define SC16IS7XX_MSR_CTS_BIT BIT(4) /* CTS */
208#define SC16IS7XX_MSR_DSR_BIT BIT(5) /* DSR (IO4)
209 * - only on 75x/76x
210 */
211#define SC16IS7XX_MSR_RI_BIT BIT(6) /* RI (IO7)
212 * - only on 75x/76x
213 */
214#define SC16IS7XX_MSR_CD_BIT BIT(7) /* CD (IO6)
215 * - only on 75x/76x
216 */
217
218/*
219 * TCR register bits
220 * TCR trigger levels are available from 0 to 60 characters with a granularity
221 * of four.
222 * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
223 * no built-in hardware check to make sure this condition is met. Also, the TCR
224 * must be programmed with this condition before auto RTS or software flow
225 * control is enabled to avoid spurious operation of the device.
226 */
227#define SC16IS7XX_TCR_RX_HALT(words) ((((words) / 4) & 0x0f) << 0)
228#define SC16IS7XX_TCR_RX_RESUME(words) ((((words) / 4) & 0x0f) << 4)
229
230/*
231 * TLR register bits
232 * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
233 * FIFO Control Register (FCR) are used for the transmit and receive FIFO
234 * trigger levels. Trigger levels from 4 characters to 60 characters are
235 * available with a granularity of four.
236 *
237 * When the trigger level setting in TLR is zero, the SC16IS74x/75x/76x uses the
238 * trigger level setting defined in FCR. If TLR has non-zero trigger level value
239 * the trigger level defined in FCR is discarded. This applies to both transmit
240 * FIFO and receive FIFO trigger level setting.
241 *
242 * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
243 * default state, that is, '00'.
244 */
245#define SC16IS7XX_TLR_TX_TRIGGER(words) ((((words) / 4) & 0x0f) << 0)
246#define SC16IS7XX_TLR_RX_TRIGGER(words) ((((words) / 4) & 0x0f) << 4)
247
248/* IOControl register bits (Only 75x/76x) */
249#define SC16IS7XX_IOCONTROL_LATCH_BIT BIT(0) /* Enable input latching */
250#define SC16IS7XX_IOCONTROL_MODEM_A_BIT BIT(1) /* Enable GPIO[7:4] as modem A pins */
251#define SC16IS7XX_IOCONTROL_MODEM_B_BIT BIT(2) /* Enable GPIO[3:0] as modem B pins */
252#define SC16IS7XX_IOCONTROL_SRESET_BIT BIT(3) /* Software Reset */
253
254/* EFCR register bits */
255#define SC16IS7XX_EFCR_9BIT_MODE_BIT BIT(0) /* Enable 9-bit or Multidrop
256 * mode (RS485) */
257#define SC16IS7XX_EFCR_RXDISABLE_BIT BIT(1) /* Disable receiver */
258#define SC16IS7XX_EFCR_TXDISABLE_BIT BIT(2) /* Disable transmitter */
259#define SC16IS7XX_EFCR_AUTO_RS485_BIT BIT(4) /* Auto RS485 RTS direction */
260#define SC16IS7XX_EFCR_RTS_INVERT_BIT BIT(5) /* RTS output inversion */
261#define SC16IS7XX_EFCR_IRDA_MODE_BIT BIT(7) /* IrDA mode
262 * 0 = rate upto 115.2 kbit/s
263 * - Only 75x/76x
264 * 1 = rate upto 1.152 Mbit/s
265 * - Only 76x
266 */
267
268/* EFR register bits */
269#define SC16IS7XX_EFR_AUTORTS_BIT BIT(6) /* Auto RTS flow ctrl enable */
270#define SC16IS7XX_EFR_AUTOCTS_BIT BIT(7) /* Auto CTS flow ctrl enable */
271#define SC16IS7XX_EFR_XOFF2_DETECT_BIT BIT(5) /* Enable Xoff2 detection */
272#define SC16IS7XX_EFR_ENABLE_BIT BIT(4) /* Enable enhanced functions
273 * and writing to IER[7:4],
274 * FCR[5:4], MCR[7:5]
275 */
276#define SC16IS7XX_EFR_SWFLOW3_BIT BIT(3)
277#define SC16IS7XX_EFR_SWFLOW2_BIT BIT(2)
278 /*
279 * SWFLOW bits 3 & 2 table:
280 * 00 -> no transmitter flow
281 * control
282 * 01 -> transmitter generates
283 * XON2 and XOFF2
284 * 10 -> transmitter generates
285 * XON1 and XOFF1
286 * 11 -> transmitter generates
287 * XON1, XON2, XOFF1 and
288 * XOFF2
289 */
290#define SC16IS7XX_EFR_SWFLOW1_BIT BIT(1)
291#define SC16IS7XX_EFR_SWFLOW0_BIT BIT(0)
292 /*
293 * SWFLOW bits 1 & 0 table:
294 * 00 -> no received flow
295 * control
296 * 01 -> receiver compares
297 * XON2 and XOFF2
298 * 10 -> receiver compares
299 * XON1 and XOFF1
300 * 11 -> receiver compares
301 * XON1, XON2, XOFF1 and
302 * XOFF2
303 */
304#define SC16IS7XX_EFR_FLOWCTRL_BITS (SC16IS7XX_EFR_AUTORTS_BIT | \
305 SC16IS7XX_EFR_AUTOCTS_BIT | \
306 SC16IS7XX_EFR_XOFF2_DETECT_BIT | \
307 SC16IS7XX_EFR_SWFLOW3_BIT | \
308 SC16IS7XX_EFR_SWFLOW2_BIT | \
309 SC16IS7XX_EFR_SWFLOW1_BIT | \
310 SC16IS7XX_EFR_SWFLOW0_BIT)
311
312
313/* Misc definitions */
314#define SC16IS7XX_FIFO_SIZE (64)
315#define SC16IS7XX_GPIOS_PER_BANK 4
316
317#define SC16IS7XX_RECONF_MD BIT(0)
318#define SC16IS7XX_RECONF_IER BIT(1)
319#define SC16IS7XX_RECONF_RS485 BIT(2)
320
321struct sc16is7xx_one_config {
322 unsigned int flags;
323 u8 ier_mask;
324 u8 ier_val;
325};
326
327struct sc16is7xx_one {
328 struct uart_port port;
329 struct regmap *regmap;
330 struct mutex efr_lock; /* EFR registers access */
331 struct kthread_work tx_work;
332 struct kthread_work reg_work;
333 struct kthread_delayed_work ms_work;
334 struct sc16is7xx_one_config config;
335 unsigned char buf[SC16IS7XX_FIFO_SIZE]; /* Rx buffer. */
336 unsigned int old_mctrl;
337 u8 old_lcr; /* Value before EFR access. */
338 bool irda_mode;
339};
340
341struct sc16is7xx_port {
342 const struct sc16is7xx_devtype *devtype;
343 struct clk *clk;
344#ifdef CONFIG_GPIOLIB
345 struct gpio_chip gpio;
346 unsigned long gpio_valid_mask;
347#endif
348 u8 mctrl_mask;
349 struct kthread_worker kworker;
350 struct task_struct *kworker_task;
351 struct sc16is7xx_one p[];
352};
353
354static DEFINE_IDA(sc16is7xx_lines);
355
356static struct uart_driver sc16is7xx_uart = {
357 .owner = THIS_MODULE,
358 .driver_name = SC16IS7XX_NAME,
359 .dev_name = "ttySC",
360 .nr = SC16IS7XX_MAX_DEVS,
361};
362
363#define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e)))
364
365static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
366{
367 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
368 unsigned int val = 0;
369
370 regmap_read(one->regmap, reg, &val);
371
372 return val;
373}
374
375static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
376{
377 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
378
379 regmap_write(one->regmap, reg, val);
380}
381
382static void sc16is7xx_fifo_read(struct uart_port *port, u8 *rxbuf, unsigned int rxlen)
383{
384 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
385
386 regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, rxbuf, rxlen);
387}
388
389static void sc16is7xx_fifo_write(struct uart_port *port, u8 *txbuf, u8 to_send)
390{
391 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
392
393 /*
394 * Don't send zero-length data, at least on SPI it confuses the chip
395 * delivering wrong TXLVL data.
396 */
397 if (unlikely(!to_send))
398 return;
399
400 regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, txbuf, to_send);
401}
402
403static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
404 u8 mask, u8 val)
405{
406 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
407
408 regmap_update_bits(one->regmap, reg, mask, val);
409}
410
411static void sc16is7xx_power(struct uart_port *port, int on)
412{
413 sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
414 SC16IS7XX_IER_SLEEP_BIT,
415 on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
416}
417
418/*
419 * In an amazing feat of design, the Enhanced Features Register (EFR)
420 * shares the address of the Interrupt Identification Register (IIR).
421 * Access to EFR is switched on by writing a magic value (0xbf) to the
422 * Line Control Register (LCR). Any interrupt firing during this time will
423 * see the EFR where it expects the IIR to be, leading to
424 * "Unexpected interrupt" messages.
425 *
426 * Prevent this possibility by claiming a mutex while accessing the EFR,
427 * and claiming the same mutex from within the interrupt handler. This is
428 * similar to disabling the interrupt, but that doesn't work because the
429 * bulk of the interrupt processing is run as a workqueue job in thread
430 * context.
431 */
432static void sc16is7xx_efr_lock(struct uart_port *port)
433{
434 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
435
436 mutex_lock(&one->efr_lock);
437
438 /* Backup content of LCR. */
439 one->old_lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
440
441 /* Enable access to Enhanced register set */
442 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B);
443
444 /* Disable cache updates when writing to EFR registers */
445 regcache_cache_bypass(one->regmap, true);
446}
447
448static void sc16is7xx_efr_unlock(struct uart_port *port)
449{
450 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
451
452 /* Re-enable cache updates when writing to normal registers */
453 regcache_cache_bypass(one->regmap, false);
454
455 /* Restore original content of LCR */
456 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, one->old_lcr);
457
458 mutex_unlock(&one->efr_lock);
459}
460
461static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
462{
463 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
464 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
465
466 lockdep_assert_held_once(&port->lock);
467
468 one->config.flags |= SC16IS7XX_RECONF_IER;
469 one->config.ier_mask |= bit;
470 one->config.ier_val &= ~bit;
471 kthread_queue_work(&s->kworker, &one->reg_work);
472}
473
474static void sc16is7xx_ier_set(struct uart_port *port, u8 bit)
475{
476 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
477 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
478
479 lockdep_assert_held_once(&port->lock);
480
481 one->config.flags |= SC16IS7XX_RECONF_IER;
482 one->config.ier_mask |= bit;
483 one->config.ier_val |= bit;
484 kthread_queue_work(&s->kworker, &one->reg_work);
485}
486
487static void sc16is7xx_stop_tx(struct uart_port *port)
488{
489 sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
490}
491
492static void sc16is7xx_stop_rx(struct uart_port *port)
493{
494 sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
495}
496
497const struct sc16is7xx_devtype sc16is74x_devtype = {
498 .name = "SC16IS74X",
499 .nr_gpio = 0,
500 .nr_uart = 1,
501};
502EXPORT_SYMBOL_GPL(sc16is74x_devtype);
503
504const struct sc16is7xx_devtype sc16is750_devtype = {
505 .name = "SC16IS750",
506 .nr_gpio = 8,
507 .nr_uart = 1,
508};
509EXPORT_SYMBOL_GPL(sc16is750_devtype);
510
511const struct sc16is7xx_devtype sc16is752_devtype = {
512 .name = "SC16IS752",
513 .nr_gpio = 8,
514 .nr_uart = 2,
515};
516EXPORT_SYMBOL_GPL(sc16is752_devtype);
517
518const struct sc16is7xx_devtype sc16is760_devtype = {
519 .name = "SC16IS760",
520 .nr_gpio = 8,
521 .nr_uart = 1,
522};
523EXPORT_SYMBOL_GPL(sc16is760_devtype);
524
525const struct sc16is7xx_devtype sc16is762_devtype = {
526 .name = "SC16IS762",
527 .nr_gpio = 8,
528 .nr_uart = 2,
529};
530EXPORT_SYMBOL_GPL(sc16is762_devtype);
531
532static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
533{
534 switch (reg) {
535 case SC16IS7XX_RHR_REG:
536 case SC16IS7XX_IIR_REG:
537 case SC16IS7XX_LSR_REG:
538 case SC16IS7XX_MSR_REG:
539 case SC16IS7XX_TXLVL_REG:
540 case SC16IS7XX_RXLVL_REG:
541 case SC16IS7XX_IOSTATE_REG:
542 case SC16IS7XX_IOCONTROL_REG:
543 return true;
544 default:
545 return false;
546 }
547}
548
549static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
550{
551 switch (reg) {
552 case SC16IS7XX_RHR_REG:
553 return true;
554 default:
555 return false;
556 }
557}
558
559static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
560{
561 return reg == SC16IS7XX_RHR_REG;
562}
563
564/*
565 * Configure programmable baud rate generator (divisor) according to the
566 * desired baud rate.
567 *
568 * From the datasheet, the divisor is computed according to:
569 *
570 * XTAL1 input frequency
571 * -----------------------
572 * prescaler
573 * divisor = ---------------------------
574 * baud-rate x sampling-rate
575 */
576static int sc16is7xx_set_baud(struct uart_port *port, int baud)
577{
578 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
579 u8 lcr;
580 unsigned int prescaler = 1;
581 unsigned long clk = port->uartclk, div = clk / 16 / baud;
582
583 if (div >= BIT(16)) {
584 prescaler = 4;
585 div /= prescaler;
586 }
587
588 /* Enable enhanced features */
589 sc16is7xx_efr_lock(port);
590 sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
591 SC16IS7XX_EFR_ENABLE_BIT,
592 SC16IS7XX_EFR_ENABLE_BIT);
593 sc16is7xx_efr_unlock(port);
594
595 /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */
596 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
597 SC16IS7XX_MCR_CLKSEL_BIT,
598 prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT);
599
600 mutex_lock(&one->efr_lock);
601
602 /* Backup LCR and access special register set (DLL/DLH) */
603 lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
604 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
605 SC16IS7XX_LCR_CONF_MODE_A);
606
607 /* Write the new divisor */
608 regcache_cache_bypass(one->regmap, true);
609 sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
610 sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
611 regcache_cache_bypass(one->regmap, false);
612
613 /* Restore LCR and access to general register set */
614 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
615
616 mutex_unlock(&one->efr_lock);
617
618 return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div);
619}
620
621static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
622 unsigned int iir)
623{
624 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
625 unsigned int lsr = 0, bytes_read, i;
626 bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
627 u8 ch, flag;
628
629 if (unlikely(rxlen >= sizeof(one->buf))) {
630 dev_warn_ratelimited(port->dev,
631 "ttySC%i: Possible RX FIFO overrun: %d\n",
632 port->line, rxlen);
633 port->icount.buf_overrun++;
634 /* Ensure sanity of RX level */
635 rxlen = sizeof(one->buf);
636 }
637
638 while (rxlen) {
639 /* Only read lsr if there are possible errors in FIFO */
640 if (read_lsr) {
641 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
642 if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
643 read_lsr = false; /* No errors left in FIFO */
644 } else
645 lsr = 0;
646
647 if (read_lsr) {
648 one->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
649 bytes_read = 1;
650 } else {
651 sc16is7xx_fifo_read(port, one->buf, rxlen);
652 bytes_read = rxlen;
653 }
654
655 lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
656
657 port->icount.rx++;
658 flag = TTY_NORMAL;
659
660 if (unlikely(lsr)) {
661 if (lsr & SC16IS7XX_LSR_BI_BIT) {
662 port->icount.brk++;
663 if (uart_handle_break(port))
664 continue;
665 } else if (lsr & SC16IS7XX_LSR_PE_BIT)
666 port->icount.parity++;
667 else if (lsr & SC16IS7XX_LSR_FE_BIT)
668 port->icount.frame++;
669 else if (lsr & SC16IS7XX_LSR_OE_BIT)
670 port->icount.overrun++;
671
672 lsr &= port->read_status_mask;
673 if (lsr & SC16IS7XX_LSR_BI_BIT)
674 flag = TTY_BREAK;
675 else if (lsr & SC16IS7XX_LSR_PE_BIT)
676 flag = TTY_PARITY;
677 else if (lsr & SC16IS7XX_LSR_FE_BIT)
678 flag = TTY_FRAME;
679 else if (lsr & SC16IS7XX_LSR_OE_BIT)
680 flag = TTY_OVERRUN;
681 }
682
683 for (i = 0; i < bytes_read; ++i) {
684 ch = one->buf[i];
685 if (uart_handle_sysrq_char(port, ch))
686 continue;
687
688 if (lsr & port->ignore_status_mask)
689 continue;
690
691 uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
692 flag);
693 }
694 rxlen -= bytes_read;
695 }
696
697 tty_flip_buffer_push(&port->state->port);
698}
699
700static void sc16is7xx_handle_tx(struct uart_port *port)
701{
702 struct tty_port *tport = &port->state->port;
703 unsigned long flags;
704 unsigned int txlen;
705 unsigned char *tail;
706
707 if (unlikely(port->x_char)) {
708 sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
709 port->icount.tx++;
710 port->x_char = 0;
711 return;
712 }
713
714 if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) {
715 uart_port_lock_irqsave(port, &flags);
716 sc16is7xx_stop_tx(port);
717 uart_port_unlock_irqrestore(port, flags);
718 return;
719 }
720
721 /* Limit to space available in TX FIFO */
722 txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
723 if (txlen > SC16IS7XX_FIFO_SIZE) {
724 dev_err_ratelimited(port->dev,
725 "chip reports %d free bytes in TX fifo, but it only has %d",
726 txlen, SC16IS7XX_FIFO_SIZE);
727 txlen = 0;
728 }
729
730 txlen = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail, txlen);
731 sc16is7xx_fifo_write(port, tail, txlen);
732 uart_xmit_advance(port, txlen);
733
734 uart_port_lock_irqsave(port, &flags);
735 if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
736 uart_write_wakeup(port);
737
738 if (kfifo_is_empty(&tport->xmit_fifo))
739 sc16is7xx_stop_tx(port);
740 else
741 sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
742 uart_port_unlock_irqrestore(port, flags);
743}
744
745static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
746{
747 u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
748 unsigned int mctrl = 0;
749
750 mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
751 mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0;
752 mctrl |= (msr & SC16IS7XX_MSR_CD_BIT) ? TIOCM_CAR : 0;
753 mctrl |= (msr & SC16IS7XX_MSR_RI_BIT) ? TIOCM_RNG : 0;
754 return mctrl;
755}
756
757static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
758{
759 struct uart_port *port = &one->port;
760 unsigned long flags;
761 unsigned int status, changed;
762
763 lockdep_assert_held_once(&one->efr_lock);
764
765 status = sc16is7xx_get_hwmctrl(port);
766 changed = status ^ one->old_mctrl;
767
768 if (changed == 0)
769 return;
770
771 one->old_mctrl = status;
772
773 uart_port_lock_irqsave(port, &flags);
774 if ((changed & TIOCM_RNG) && (status & TIOCM_RNG))
775 port->icount.rng++;
776 if (changed & TIOCM_DSR)
777 port->icount.dsr++;
778 if (changed & TIOCM_CAR)
779 uart_handle_dcd_change(port, status & TIOCM_CAR);
780 if (changed & TIOCM_CTS)
781 uart_handle_cts_change(port, status & TIOCM_CTS);
782
783 wake_up_interruptible(&port->state->port.delta_msr_wait);
784 uart_port_unlock_irqrestore(port, flags);
785}
786
787static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
788{
789 bool rc = true;
790 unsigned int iir, rxlen;
791 struct uart_port *port = &s->p[portno].port;
792 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
793
794 mutex_lock(&one->efr_lock);
795
796 iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
797 if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
798 rc = false;
799 goto out_port_irq;
800 }
801
802 iir &= SC16IS7XX_IIR_ID_MASK;
803
804 switch (iir) {
805 case SC16IS7XX_IIR_RDI_SRC:
806 case SC16IS7XX_IIR_RLSE_SRC:
807 case SC16IS7XX_IIR_RTOI_SRC:
808 case SC16IS7XX_IIR_XOFFI_SRC:
809 rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
810
811 /*
812 * There is a silicon bug that makes the chip report a
813 * time-out interrupt but no data in the FIFO. This is
814 * described in errata section 18.1.4.
815 *
816 * When this happens, read one byte from the FIFO to
817 * clear the interrupt.
818 */
819 if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen)
820 rxlen = 1;
821
822 if (rxlen)
823 sc16is7xx_handle_rx(port, rxlen, iir);
824 break;
825 /* CTSRTS interrupt comes only when CTS goes inactive */
826 case SC16IS7XX_IIR_CTSRTS_SRC:
827 case SC16IS7XX_IIR_MSI_SRC:
828 sc16is7xx_update_mlines(one);
829 break;
830 case SC16IS7XX_IIR_THRI_SRC:
831 sc16is7xx_handle_tx(port);
832 break;
833 default:
834 dev_err_ratelimited(port->dev,
835 "ttySC%i: Unexpected interrupt: %x",
836 port->line, iir);
837 break;
838 }
839
840out_port_irq:
841 mutex_unlock(&one->efr_lock);
842
843 return rc;
844}
845
846static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
847{
848 bool keep_polling;
849
850 struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
851
852 do {
853 int i;
854
855 keep_polling = false;
856
857 for (i = 0; i < s->devtype->nr_uart; ++i)
858 keep_polling |= sc16is7xx_port_irq(s, i);
859 } while (keep_polling);
860
861 return IRQ_HANDLED;
862}
863
864static void sc16is7xx_tx_proc(struct kthread_work *ws)
865{
866 struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
867 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
868
869 if ((port->rs485.flags & SER_RS485_ENABLED) &&
870 (port->rs485.delay_rts_before_send > 0))
871 msleep(port->rs485.delay_rts_before_send);
872
873 mutex_lock(&one->efr_lock);
874 sc16is7xx_handle_tx(port);
875 mutex_unlock(&one->efr_lock);
876}
877
878static void sc16is7xx_reconf_rs485(struct uart_port *port)
879{
880 const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
881 SC16IS7XX_EFCR_RTS_INVERT_BIT;
882 u32 efcr = 0;
883 struct serial_rs485 *rs485 = &port->rs485;
884 unsigned long irqflags;
885
886 uart_port_lock_irqsave(port, &irqflags);
887 if (rs485->flags & SER_RS485_ENABLED) {
888 efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT;
889
890 if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
891 efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
892 }
893 uart_port_unlock_irqrestore(port, irqflags);
894
895 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
896}
897
898static void sc16is7xx_reg_proc(struct kthread_work *ws)
899{
900 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
901 struct sc16is7xx_one_config config;
902 unsigned long irqflags;
903
904 uart_port_lock_irqsave(&one->port, &irqflags);
905 config = one->config;
906 memset(&one->config, 0, sizeof(one->config));
907 uart_port_unlock_irqrestore(&one->port, irqflags);
908
909 if (config.flags & SC16IS7XX_RECONF_MD) {
910 u8 mcr = 0;
911
912 /* Device ignores RTS setting when hardware flow is enabled */
913 if (one->port.mctrl & TIOCM_RTS)
914 mcr |= SC16IS7XX_MCR_RTS_BIT;
915
916 if (one->port.mctrl & TIOCM_DTR)
917 mcr |= SC16IS7XX_MCR_DTR_BIT;
918
919 if (one->port.mctrl & TIOCM_LOOP)
920 mcr |= SC16IS7XX_MCR_LOOP_BIT;
921 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
922 SC16IS7XX_MCR_RTS_BIT |
923 SC16IS7XX_MCR_DTR_BIT |
924 SC16IS7XX_MCR_LOOP_BIT,
925 mcr);
926 }
927
928 if (config.flags & SC16IS7XX_RECONF_IER)
929 sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
930 config.ier_mask, config.ier_val);
931
932 if (config.flags & SC16IS7XX_RECONF_RS485)
933 sc16is7xx_reconf_rs485(&one->port);
934}
935
936static void sc16is7xx_ms_proc(struct kthread_work *ws)
937{
938 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work);
939 struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
940
941 if (one->port.state) {
942 mutex_lock(&one->efr_lock);
943 sc16is7xx_update_mlines(one);
944 mutex_unlock(&one->efr_lock);
945
946 kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
947 }
948}
949
950static void sc16is7xx_enable_ms(struct uart_port *port)
951{
952 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
953 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
954
955 lockdep_assert_held_once(&port->lock);
956
957 kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0);
958}
959
960static void sc16is7xx_start_tx(struct uart_port *port)
961{
962 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
963 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
964
965 kthread_queue_work(&s->kworker, &one->tx_work);
966}
967
968static void sc16is7xx_throttle(struct uart_port *port)
969{
970 unsigned long flags;
971
972 /*
973 * Hardware flow control is enabled and thus the device ignores RTS
974 * value set in MCR register. Stop reading data from RX FIFO so the
975 * AutoRTS feature will de-activate RTS output.
976 */
977 uart_port_lock_irqsave(port, &flags);
978 sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
979 uart_port_unlock_irqrestore(port, flags);
980}
981
982static void sc16is7xx_unthrottle(struct uart_port *port)
983{
984 unsigned long flags;
985
986 uart_port_lock_irqsave(port, &flags);
987 sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT);
988 uart_port_unlock_irqrestore(port, flags);
989}
990
991static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
992{
993 unsigned int lsr;
994
995 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
996
997 return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
998}
999
1000static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
1001{
1002 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1003
1004 /* Called with port lock taken so we can only return cached value */
1005 return one->old_mctrl;
1006}
1007
1008static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
1009{
1010 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1011 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1012
1013 one->config.flags |= SC16IS7XX_RECONF_MD;
1014 kthread_queue_work(&s->kworker, &one->reg_work);
1015}
1016
1017static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
1018{
1019 sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
1020 SC16IS7XX_LCR_TXBREAK_BIT,
1021 break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
1022}
1023
1024static void sc16is7xx_set_termios(struct uart_port *port,
1025 struct ktermios *termios,
1026 const struct ktermios *old)
1027{
1028 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1029 unsigned int lcr, flow = 0;
1030 int baud;
1031 unsigned long flags;
1032
1033 kthread_cancel_delayed_work_sync(&one->ms_work);
1034
1035 /* Mask termios capabilities we don't support */
1036 termios->c_cflag &= ~CMSPAR;
1037
1038 /* Word size */
1039 switch (termios->c_cflag & CSIZE) {
1040 case CS5:
1041 lcr = SC16IS7XX_LCR_WORD_LEN_5;
1042 break;
1043 case CS6:
1044 lcr = SC16IS7XX_LCR_WORD_LEN_6;
1045 break;
1046 case CS7:
1047 lcr = SC16IS7XX_LCR_WORD_LEN_7;
1048 break;
1049 case CS8:
1050 lcr = SC16IS7XX_LCR_WORD_LEN_8;
1051 break;
1052 default:
1053 lcr = SC16IS7XX_LCR_WORD_LEN_8;
1054 termios->c_cflag &= ~CSIZE;
1055 termios->c_cflag |= CS8;
1056 break;
1057 }
1058
1059 /* Parity */
1060 if (termios->c_cflag & PARENB) {
1061 lcr |= SC16IS7XX_LCR_PARITY_BIT;
1062 if (!(termios->c_cflag & PARODD))
1063 lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
1064 }
1065
1066 /* Stop bits */
1067 if (termios->c_cflag & CSTOPB)
1068 lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
1069
1070 /* Set read status mask */
1071 port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
1072 if (termios->c_iflag & INPCK)
1073 port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
1074 SC16IS7XX_LSR_FE_BIT;
1075 if (termios->c_iflag & (BRKINT | PARMRK))
1076 port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
1077
1078 /* Set status ignore mask */
1079 port->ignore_status_mask = 0;
1080 if (termios->c_iflag & IGNBRK)
1081 port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
1082 if (!(termios->c_cflag & CREAD))
1083 port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
1084
1085 /* Configure flow control */
1086 port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
1087 if (termios->c_cflag & CRTSCTS) {
1088 flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
1089 SC16IS7XX_EFR_AUTORTS_BIT;
1090 port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1091 }
1092 if (termios->c_iflag & IXON)
1093 flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
1094 if (termios->c_iflag & IXOFF)
1095 flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
1096
1097 /* Update LCR register */
1098 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
1099
1100 /* Update EFR registers */
1101 sc16is7xx_efr_lock(port);
1102 sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
1103 sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
1104 sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1105 SC16IS7XX_EFR_FLOWCTRL_BITS, flow);
1106 sc16is7xx_efr_unlock(port);
1107
1108 /* Get baud rate generator configuration */
1109 baud = uart_get_baud_rate(port, termios, old,
1110 port->uartclk / 16 / 4 / 0xffff,
1111 port->uartclk / 16);
1112
1113 /* Setup baudrate generator */
1114 baud = sc16is7xx_set_baud(port, baud);
1115
1116 uart_port_lock_irqsave(port, &flags);
1117
1118 /* Update timeout according to new baud rate */
1119 uart_update_timeout(port, termios->c_cflag, baud);
1120
1121 if (UART_ENABLE_MS(port, termios->c_cflag))
1122 sc16is7xx_enable_ms(port);
1123
1124 uart_port_unlock_irqrestore(port, flags);
1125}
1126
1127static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios,
1128 struct serial_rs485 *rs485)
1129{
1130 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1131 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1132
1133 if (rs485->flags & SER_RS485_ENABLED) {
1134 /*
1135 * RTS signal is handled by HW, it's timing can't be influenced.
1136 * However, it's sometimes useful to delay TX even without RTS
1137 * control therefore we try to handle .delay_rts_before_send.
1138 */
1139 if (rs485->delay_rts_after_send)
1140 return -EINVAL;
1141 }
1142
1143 one->config.flags |= SC16IS7XX_RECONF_RS485;
1144 kthread_queue_work(&s->kworker, &one->reg_work);
1145
1146 return 0;
1147}
1148
1149static int sc16is7xx_startup(struct uart_port *port)
1150{
1151 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1152 unsigned int val;
1153 unsigned long flags;
1154
1155 sc16is7xx_power(port, 1);
1156
1157 /* Reset FIFOs*/
1158 val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
1159 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
1160 udelay(5);
1161 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
1162 SC16IS7XX_FCR_FIFO_BIT);
1163
1164 /* Enable EFR */
1165 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
1166 SC16IS7XX_LCR_CONF_MODE_B);
1167
1168 regcache_cache_bypass(one->regmap, true);
1169
1170 /* Enable write access to enhanced features and internal clock div */
1171 sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1172 SC16IS7XX_EFR_ENABLE_BIT,
1173 SC16IS7XX_EFR_ENABLE_BIT);
1174
1175 /* Enable TCR/TLR */
1176 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1177 SC16IS7XX_MCR_TCRTLR_BIT,
1178 SC16IS7XX_MCR_TCRTLR_BIT);
1179
1180 /* Configure flow control levels */
1181 /* Flow control halt level 48, resume level 24 */
1182 sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
1183 SC16IS7XX_TCR_RX_RESUME(24) |
1184 SC16IS7XX_TCR_RX_HALT(48));
1185
1186 regcache_cache_bypass(one->regmap, false);
1187
1188 /* Now, initialize the UART */
1189 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
1190
1191 /* Enable IrDA mode if requested in DT */
1192 /* This bit must be written with LCR[7] = 0 */
1193 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1194 SC16IS7XX_MCR_IRDA_BIT,
1195 one->irda_mode ?
1196 SC16IS7XX_MCR_IRDA_BIT : 0);
1197
1198 /* Enable the Rx and Tx FIFO */
1199 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1200 SC16IS7XX_EFCR_RXDISABLE_BIT |
1201 SC16IS7XX_EFCR_TXDISABLE_BIT,
1202 0);
1203
1204 /* Enable RX, CTS change and modem lines interrupts */
1205 val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT |
1206 SC16IS7XX_IER_MSI_BIT;
1207 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1208
1209 /* Enable modem status polling */
1210 uart_port_lock_irqsave(port, &flags);
1211 sc16is7xx_enable_ms(port);
1212 uart_port_unlock_irqrestore(port, flags);
1213
1214 return 0;
1215}
1216
1217static void sc16is7xx_shutdown(struct uart_port *port)
1218{
1219 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1220 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1221
1222 kthread_cancel_delayed_work_sync(&one->ms_work);
1223
1224 /* Disable all interrupts */
1225 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1226 /* Disable TX/RX */
1227 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1228 SC16IS7XX_EFCR_RXDISABLE_BIT |
1229 SC16IS7XX_EFCR_TXDISABLE_BIT,
1230 SC16IS7XX_EFCR_RXDISABLE_BIT |
1231 SC16IS7XX_EFCR_TXDISABLE_BIT);
1232
1233 sc16is7xx_power(port, 0);
1234
1235 kthread_flush_worker(&s->kworker);
1236}
1237
1238static const char *sc16is7xx_type(struct uart_port *port)
1239{
1240 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1241
1242 return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1243}
1244
1245static int sc16is7xx_request_port(struct uart_port *port)
1246{
1247 /* Do nothing */
1248 return 0;
1249}
1250
1251static void sc16is7xx_config_port(struct uart_port *port, int flags)
1252{
1253 if (flags & UART_CONFIG_TYPE)
1254 port->type = PORT_SC16IS7XX;
1255}
1256
1257static int sc16is7xx_verify_port(struct uart_port *port,
1258 struct serial_struct *s)
1259{
1260 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1261 return -EINVAL;
1262 if (s->irq != port->irq)
1263 return -EINVAL;
1264
1265 return 0;
1266}
1267
1268static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1269 unsigned int oldstate)
1270{
1271 sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1272}
1273
1274static void sc16is7xx_null_void(struct uart_port *port)
1275{
1276 /* Do nothing */
1277}
1278
1279static const struct uart_ops sc16is7xx_ops = {
1280 .tx_empty = sc16is7xx_tx_empty,
1281 .set_mctrl = sc16is7xx_set_mctrl,
1282 .get_mctrl = sc16is7xx_get_mctrl,
1283 .stop_tx = sc16is7xx_stop_tx,
1284 .start_tx = sc16is7xx_start_tx,
1285 .throttle = sc16is7xx_throttle,
1286 .unthrottle = sc16is7xx_unthrottle,
1287 .stop_rx = sc16is7xx_stop_rx,
1288 .enable_ms = sc16is7xx_enable_ms,
1289 .break_ctl = sc16is7xx_break_ctl,
1290 .startup = sc16is7xx_startup,
1291 .shutdown = sc16is7xx_shutdown,
1292 .set_termios = sc16is7xx_set_termios,
1293 .type = sc16is7xx_type,
1294 .request_port = sc16is7xx_request_port,
1295 .release_port = sc16is7xx_null_void,
1296 .config_port = sc16is7xx_config_port,
1297 .verify_port = sc16is7xx_verify_port,
1298 .pm = sc16is7xx_pm,
1299};
1300
1301#ifdef CONFIG_GPIOLIB
1302static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1303{
1304 unsigned int val;
1305 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1306 struct uart_port *port = &s->p[0].port;
1307
1308 val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1309
1310 return !!(val & BIT(offset));
1311}
1312
1313static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1314{
1315 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1316 struct uart_port *port = &s->p[0].port;
1317
1318 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1319 val ? BIT(offset) : 0);
1320}
1321
1322static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1323 unsigned offset)
1324{
1325 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1326 struct uart_port *port = &s->p[0].port;
1327
1328 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1329
1330 return 0;
1331}
1332
1333static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1334 unsigned offset, int val)
1335{
1336 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1337 struct uart_port *port = &s->p[0].port;
1338 u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1339
1340 if (val)
1341 state |= BIT(offset);
1342 else
1343 state &= ~BIT(offset);
1344
1345 /*
1346 * If we write IOSTATE first, and then IODIR, the output value is not
1347 * transferred to the corresponding I/O pin.
1348 * The datasheet states that each register bit will be transferred to
1349 * the corresponding I/O pin programmed as output when writing to
1350 * IOSTATE. Therefore, configure direction first with IODIR, and then
1351 * set value after with IOSTATE.
1352 */
1353 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1354 BIT(offset));
1355 sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
1356
1357 return 0;
1358}
1359
1360static int sc16is7xx_gpio_init_valid_mask(struct gpio_chip *chip,
1361 unsigned long *valid_mask,
1362 unsigned int ngpios)
1363{
1364 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1365
1366 *valid_mask = s->gpio_valid_mask;
1367
1368 return 0;
1369}
1370
1371static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s)
1372{
1373 struct device *dev = s->p[0].port.dev;
1374
1375 if (!s->devtype->nr_gpio)
1376 return 0;
1377
1378 switch (s->mctrl_mask) {
1379 case 0:
1380 s->gpio_valid_mask = GENMASK(7, 0);
1381 break;
1382 case SC16IS7XX_IOCONTROL_MODEM_A_BIT:
1383 s->gpio_valid_mask = GENMASK(3, 0);
1384 break;
1385 case SC16IS7XX_IOCONTROL_MODEM_B_BIT:
1386 s->gpio_valid_mask = GENMASK(7, 4);
1387 break;
1388 default:
1389 break;
1390 }
1391
1392 if (s->gpio_valid_mask == 0)
1393 return 0;
1394
1395 s->gpio.owner = THIS_MODULE;
1396 s->gpio.parent = dev;
1397 s->gpio.label = dev_name(dev);
1398 s->gpio.init_valid_mask = sc16is7xx_gpio_init_valid_mask;
1399 s->gpio.direction_input = sc16is7xx_gpio_direction_input;
1400 s->gpio.get = sc16is7xx_gpio_get;
1401 s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1402 s->gpio.set = sc16is7xx_gpio_set;
1403 s->gpio.base = -1;
1404 s->gpio.ngpio = s->devtype->nr_gpio;
1405 s->gpio.can_sleep = 1;
1406
1407 return gpiochip_add_data(&s->gpio, s);
1408}
1409#endif
1410
1411static void sc16is7xx_setup_irda_ports(struct sc16is7xx_port *s)
1412{
1413 int i;
1414 int ret;
1415 int count;
1416 u32 irda_port[SC16IS7XX_MAX_PORTS];
1417 struct device *dev = s->p[0].port.dev;
1418
1419 count = device_property_count_u32(dev, "irda-mode-ports");
1420 if (count < 0 || count > ARRAY_SIZE(irda_port))
1421 return;
1422
1423 ret = device_property_read_u32_array(dev, "irda-mode-ports",
1424 irda_port, count);
1425 if (ret)
1426 return;
1427
1428 for (i = 0; i < count; i++) {
1429 if (irda_port[i] < s->devtype->nr_uart)
1430 s->p[irda_port[i]].irda_mode = true;
1431 }
1432}
1433
1434/*
1435 * Configure ports designated to operate as modem control lines.
1436 */
1437static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
1438 struct regmap *regmap)
1439{
1440 int i;
1441 int ret;
1442 int count;
1443 u32 mctrl_port[SC16IS7XX_MAX_PORTS];
1444 struct device *dev = s->p[0].port.dev;
1445
1446 count = device_property_count_u32(dev, "nxp,modem-control-line-ports");
1447 if (count < 0 || count > ARRAY_SIZE(mctrl_port))
1448 return 0;
1449
1450 ret = device_property_read_u32_array(dev, "nxp,modem-control-line-ports",
1451 mctrl_port, count);
1452 if (ret)
1453 return ret;
1454
1455 s->mctrl_mask = 0;
1456
1457 for (i = 0; i < count; i++) {
1458 /* Use GPIO lines as modem control lines */
1459 if (mctrl_port[i] == 0)
1460 s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
1461 else if (mctrl_port[i] == 1)
1462 s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
1463 }
1464
1465 if (s->mctrl_mask)
1466 regmap_update_bits(
1467 regmap,
1468 SC16IS7XX_IOCONTROL_REG,
1469 SC16IS7XX_IOCONTROL_MODEM_A_BIT |
1470 SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask);
1471
1472 return 0;
1473}
1474
1475static const struct serial_rs485 sc16is7xx_rs485_supported = {
1476 .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
1477 .delay_rts_before_send = 1,
1478 .delay_rts_after_send = 1, /* Not supported but keep returning -EINVAL */
1479};
1480
1481/* Reset device, purging any pending irq / data */
1482static int sc16is7xx_reset(struct device *dev, struct regmap *regmap)
1483{
1484 struct gpio_desc *reset_gpio;
1485
1486 /* Assert reset GPIO if defined and valid. */
1487 reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
1488 if (IS_ERR(reset_gpio))
1489 return dev_err_probe(dev, PTR_ERR(reset_gpio), "Failed to get reset GPIO\n");
1490
1491 if (reset_gpio) {
1492 /* The minimum reset pulse width is 3 us. */
1493 fsleep(5);
1494 gpiod_set_value_cansleep(reset_gpio, 0); /* Deassert GPIO */
1495 } else {
1496 /* Software reset */
1497 regmap_write(regmap, SC16IS7XX_IOCONTROL_REG,
1498 SC16IS7XX_IOCONTROL_SRESET_BIT);
1499 }
1500
1501 return 0;
1502}
1503
1504int sc16is7xx_probe(struct device *dev, const struct sc16is7xx_devtype *devtype,
1505 struct regmap *regmaps[], int irq)
1506{
1507 unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
1508 unsigned int val;
1509 u32 uartclk = 0;
1510 int i, ret;
1511 struct sc16is7xx_port *s;
1512 bool port_registered[SC16IS7XX_MAX_PORTS];
1513
1514 for (i = 0; i < devtype->nr_uart; i++)
1515 if (IS_ERR(regmaps[i]))
1516 return PTR_ERR(regmaps[i]);
1517
1518 /*
1519 * This device does not have an identification register that would
1520 * tell us if we are really connected to the correct device.
1521 * The best we can do is to check if communication is at all possible.
1522 *
1523 * Note: regmap[0] is used in the probe function to access registers
1524 * common to all channels/ports, as it is guaranteed to be present on
1525 * all variants.
1526 */
1527 ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val);
1528 if (ret < 0)
1529 return -EPROBE_DEFER;
1530
1531 /* Alloc port structure */
1532 s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
1533 if (!s) {
1534 dev_err(dev, "Error allocating port structure\n");
1535 return -ENOMEM;
1536 }
1537
1538 /* Always ask for fixed clock rate from a property. */
1539 device_property_read_u32(dev, "clock-frequency", &uartclk);
1540
1541 s->clk = devm_clk_get_optional(dev, NULL);
1542 if (IS_ERR(s->clk))
1543 return PTR_ERR(s->clk);
1544
1545 ret = clk_prepare_enable(s->clk);
1546 if (ret)
1547 return ret;
1548
1549 freq = clk_get_rate(s->clk);
1550 if (freq == 0) {
1551 if (uartclk)
1552 freq = uartclk;
1553 if (pfreq)
1554 freq = *pfreq;
1555 if (freq)
1556 dev_dbg(dev, "Clock frequency: %luHz\n", freq);
1557 else
1558 return -EINVAL;
1559 }
1560
1561 s->devtype = devtype;
1562 dev_set_drvdata(dev, s);
1563
1564 kthread_init_worker(&s->kworker);
1565 s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1566 "sc16is7xx");
1567 if (IS_ERR(s->kworker_task)) {
1568 ret = PTR_ERR(s->kworker_task);
1569 goto out_clk;
1570 }
1571 sched_set_fifo(s->kworker_task);
1572
1573 ret = sc16is7xx_reset(dev, regmaps[0]);
1574 if (ret)
1575 goto out_kthread;
1576
1577 /* Mark each port line and status as uninitialised. */
1578 for (i = 0; i < devtype->nr_uart; ++i) {
1579 s->p[i].port.line = SC16IS7XX_MAX_DEVS;
1580 port_registered[i] = false;
1581 }
1582
1583 for (i = 0; i < devtype->nr_uart; ++i) {
1584 ret = ida_alloc_max(&sc16is7xx_lines,
1585 SC16IS7XX_MAX_DEVS - 1, GFP_KERNEL);
1586 if (ret < 0)
1587 goto out_ports;
1588
1589 s->p[i].port.line = ret;
1590
1591 /* Initialize port data */
1592 s->p[i].port.dev = dev;
1593 s->p[i].port.irq = irq;
1594 s->p[i].port.type = PORT_SC16IS7XX;
1595 s->p[i].port.fifosize = SC16IS7XX_FIFO_SIZE;
1596 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1597 s->p[i].port.iobase = i;
1598 /*
1599 * Use all ones as membase to make sure uart_configure_port() in
1600 * serial_core.c does not abort for SPI/I2C devices where the
1601 * membase address is not applicable.
1602 */
1603 s->p[i].port.membase = (void __iomem *)~0;
1604 s->p[i].port.iotype = UPIO_PORT;
1605 s->p[i].port.uartclk = freq;
1606 s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1607 s->p[i].port.rs485_supported = sc16is7xx_rs485_supported;
1608 s->p[i].port.ops = &sc16is7xx_ops;
1609 s->p[i].old_mctrl = 0;
1610 s->p[i].regmap = regmaps[i];
1611
1612 mutex_init(&s->p[i].efr_lock);
1613
1614 ret = uart_get_rs485_mode(&s->p[i].port);
1615 if (ret)
1616 goto out_ports;
1617
1618 /* Disable all interrupts */
1619 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1620 /* Disable TX/RX */
1621 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1622 SC16IS7XX_EFCR_RXDISABLE_BIT |
1623 SC16IS7XX_EFCR_TXDISABLE_BIT);
1624
1625 /* Initialize kthread work structs */
1626 kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1627 kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1628 kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc);
1629
1630 /* Register port */
1631 ret = uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1632 if (ret)
1633 goto out_ports;
1634
1635 port_registered[i] = true;
1636
1637 /* Enable EFR */
1638 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
1639 SC16IS7XX_LCR_CONF_MODE_B);
1640
1641 regcache_cache_bypass(regmaps[i], true);
1642
1643 /* Enable write access to enhanced features */
1644 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
1645 SC16IS7XX_EFR_ENABLE_BIT);
1646
1647 regcache_cache_bypass(regmaps[i], false);
1648
1649 /* Restore access to general registers */
1650 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
1651
1652 /* Go to suspend mode */
1653 sc16is7xx_power(&s->p[i].port, 0);
1654 }
1655
1656 sc16is7xx_setup_irda_ports(s);
1657
1658 ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]);
1659 if (ret)
1660 goto out_ports;
1661
1662#ifdef CONFIG_GPIOLIB
1663 ret = sc16is7xx_setup_gpio_chip(s);
1664 if (ret)
1665 goto out_ports;
1666#endif
1667
1668 /*
1669 * Setup interrupt. We first try to acquire the IRQ line as level IRQ.
1670 * If that succeeds, we can allow sharing the interrupt as well.
1671 * In case the interrupt controller doesn't support that, we fall
1672 * back to a non-shared falling-edge trigger.
1673 */
1674 ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1675 IRQF_TRIGGER_LOW | IRQF_SHARED |
1676 IRQF_ONESHOT,
1677 dev_name(dev), s);
1678 if (!ret)
1679 return 0;
1680
1681 ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1682 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1683 dev_name(dev), s);
1684 if (!ret)
1685 return 0;
1686
1687#ifdef CONFIG_GPIOLIB
1688 if (s->gpio_valid_mask)
1689 gpiochip_remove(&s->gpio);
1690#endif
1691
1692out_ports:
1693 for (i = 0; i < devtype->nr_uart; i++) {
1694 if (s->p[i].port.line < SC16IS7XX_MAX_DEVS)
1695 ida_free(&sc16is7xx_lines, s->p[i].port.line);
1696 if (port_registered[i])
1697 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1698 }
1699
1700out_kthread:
1701 kthread_stop(s->kworker_task);
1702
1703out_clk:
1704 clk_disable_unprepare(s->clk);
1705
1706 return ret;
1707}
1708EXPORT_SYMBOL_GPL(sc16is7xx_probe);
1709
1710void sc16is7xx_remove(struct device *dev)
1711{
1712 struct sc16is7xx_port *s = dev_get_drvdata(dev);
1713 int i;
1714
1715#ifdef CONFIG_GPIOLIB
1716 if (s->gpio_valid_mask)
1717 gpiochip_remove(&s->gpio);
1718#endif
1719
1720 for (i = 0; i < s->devtype->nr_uart; i++) {
1721 kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
1722 ida_free(&sc16is7xx_lines, s->p[i].port.line);
1723 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1724 sc16is7xx_power(&s->p[i].port, 0);
1725 }
1726
1727 kthread_flush_worker(&s->kworker);
1728 kthread_stop(s->kworker_task);
1729
1730 clk_disable_unprepare(s->clk);
1731}
1732EXPORT_SYMBOL_GPL(sc16is7xx_remove);
1733
1734const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1735 { .compatible = "nxp,sc16is740", .data = &sc16is74x_devtype, },
1736 { .compatible = "nxp,sc16is741", .data = &sc16is74x_devtype, },
1737 { .compatible = "nxp,sc16is750", .data = &sc16is750_devtype, },
1738 { .compatible = "nxp,sc16is752", .data = &sc16is752_devtype, },
1739 { .compatible = "nxp,sc16is760", .data = &sc16is760_devtype, },
1740 { .compatible = "nxp,sc16is762", .data = &sc16is762_devtype, },
1741 { }
1742};
1743EXPORT_SYMBOL_GPL(sc16is7xx_dt_ids);
1744MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1745
1746const struct regmap_config sc16is7xx_regcfg = {
1747 .reg_bits = 5,
1748 .pad_bits = 3,
1749 .val_bits = 8,
1750 .cache_type = REGCACHE_MAPLE,
1751 .volatile_reg = sc16is7xx_regmap_volatile,
1752 .precious_reg = sc16is7xx_regmap_precious,
1753 .writeable_noinc_reg = sc16is7xx_regmap_noinc,
1754 .readable_noinc_reg = sc16is7xx_regmap_noinc,
1755 .max_raw_read = SC16IS7XX_FIFO_SIZE,
1756 .max_raw_write = SC16IS7XX_FIFO_SIZE,
1757 .max_register = SC16IS7XX_EFCR_REG,
1758};
1759EXPORT_SYMBOL_GPL(sc16is7xx_regcfg);
1760
1761const char *sc16is7xx_regmap_name(u8 port_id)
1762{
1763 switch (port_id) {
1764 case 0: return "port0";
1765 case 1: return "port1";
1766 default:
1767 WARN_ON(true);
1768 return NULL;
1769 }
1770}
1771EXPORT_SYMBOL_GPL(sc16is7xx_regmap_name);
1772
1773unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
1774{
1775 /* CH1,CH0 are at bits 2:1. */
1776 return port_id << 1;
1777}
1778EXPORT_SYMBOL_GPL(sc16is7xx_regmap_port_mask);
1779
1780static int __init sc16is7xx_init(void)
1781{
1782 return uart_register_driver(&sc16is7xx_uart);
1783}
1784module_init(sc16is7xx_init);
1785
1786static void __exit sc16is7xx_exit(void)
1787{
1788 uart_unregister_driver(&sc16is7xx_uart);
1789}
1790module_exit(sc16is7xx_exit);
1791
1792MODULE_LICENSE("GPL");
1793MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1794MODULE_DESCRIPTION("SC16IS7xx tty serial core driver");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * SC16IS7xx tty serial driver - Copyright (C) 2014 GridPoint
4 * Author: Jon Ringle <jringle@gridpoint.com>
5 *
6 * Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/bitops.h>
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/device.h>
15#include <linux/gpio/driver.h>
16#include <linux/i2c.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/of_device.h>
20#include <linux/regmap.h>
21#include <linux/serial_core.h>
22#include <linux/serial.h>
23#include <linux/tty.h>
24#include <linux/tty_flip.h>
25#include <linux/spi/spi.h>
26#include <linux/uaccess.h>
27#include <uapi/linux/sched/types.h>
28
29#define SC16IS7XX_NAME "sc16is7xx"
30#define SC16IS7XX_MAX_DEVS 8
31
32/* SC16IS7XX register definitions */
33#define SC16IS7XX_RHR_REG (0x00) /* RX FIFO */
34#define SC16IS7XX_THR_REG (0x00) /* TX FIFO */
35#define SC16IS7XX_IER_REG (0x01) /* Interrupt enable */
36#define SC16IS7XX_IIR_REG (0x02) /* Interrupt Identification */
37#define SC16IS7XX_FCR_REG (0x02) /* FIFO control */
38#define SC16IS7XX_LCR_REG (0x03) /* Line Control */
39#define SC16IS7XX_MCR_REG (0x04) /* Modem Control */
40#define SC16IS7XX_LSR_REG (0x05) /* Line Status */
41#define SC16IS7XX_MSR_REG (0x06) /* Modem Status */
42#define SC16IS7XX_SPR_REG (0x07) /* Scratch Pad */
43#define SC16IS7XX_TXLVL_REG (0x08) /* TX FIFO level */
44#define SC16IS7XX_RXLVL_REG (0x09) /* RX FIFO level */
45#define SC16IS7XX_IODIR_REG (0x0a) /* I/O Direction
46 * - only on 75x/76x
47 */
48#define SC16IS7XX_IOSTATE_REG (0x0b) /* I/O State
49 * - only on 75x/76x
50 */
51#define SC16IS7XX_IOINTENA_REG (0x0c) /* I/O Interrupt Enable
52 * - only on 75x/76x
53 */
54#define SC16IS7XX_IOCONTROL_REG (0x0e) /* I/O Control
55 * - only on 75x/76x
56 */
57#define SC16IS7XX_EFCR_REG (0x0f) /* Extra Features Control */
58
59/* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
60#define SC16IS7XX_TCR_REG (0x06) /* Transmit control */
61#define SC16IS7XX_TLR_REG (0x07) /* Trigger level */
62
63/* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
64#define SC16IS7XX_DLL_REG (0x00) /* Divisor Latch Low */
65#define SC16IS7XX_DLH_REG (0x01) /* Divisor Latch High */
66
67/* Enhanced Register set: Only if (LCR == 0xBF) */
68#define SC16IS7XX_EFR_REG (0x02) /* Enhanced Features */
69#define SC16IS7XX_XON1_REG (0x04) /* Xon1 word */
70#define SC16IS7XX_XON2_REG (0x05) /* Xon2 word */
71#define SC16IS7XX_XOFF1_REG (0x06) /* Xoff1 word */
72#define SC16IS7XX_XOFF2_REG (0x07) /* Xoff2 word */
73
74/* IER register bits */
75#define SC16IS7XX_IER_RDI_BIT (1 << 0) /* Enable RX data interrupt */
76#define SC16IS7XX_IER_THRI_BIT (1 << 1) /* Enable TX holding register
77 * interrupt */
78#define SC16IS7XX_IER_RLSI_BIT (1 << 2) /* Enable RX line status
79 * interrupt */
80#define SC16IS7XX_IER_MSI_BIT (1 << 3) /* Enable Modem status
81 * interrupt */
82
83/* IER register bits - write only if (EFR[4] == 1) */
84#define SC16IS7XX_IER_SLEEP_BIT (1 << 4) /* Enable Sleep mode */
85#define SC16IS7XX_IER_XOFFI_BIT (1 << 5) /* Enable Xoff interrupt */
86#define SC16IS7XX_IER_RTSI_BIT (1 << 6) /* Enable nRTS interrupt */
87#define SC16IS7XX_IER_CTSI_BIT (1 << 7) /* Enable nCTS interrupt */
88
89/* FCR register bits */
90#define SC16IS7XX_FCR_FIFO_BIT (1 << 0) /* Enable FIFO */
91#define SC16IS7XX_FCR_RXRESET_BIT (1 << 1) /* Reset RX FIFO */
92#define SC16IS7XX_FCR_TXRESET_BIT (1 << 2) /* Reset TX FIFO */
93#define SC16IS7XX_FCR_RXLVLL_BIT (1 << 6) /* RX Trigger level LSB */
94#define SC16IS7XX_FCR_RXLVLH_BIT (1 << 7) /* RX Trigger level MSB */
95
96/* FCR register bits - write only if (EFR[4] == 1) */
97#define SC16IS7XX_FCR_TXLVLL_BIT (1 << 4) /* TX Trigger level LSB */
98#define SC16IS7XX_FCR_TXLVLH_BIT (1 << 5) /* TX Trigger level MSB */
99
100/* IIR register bits */
101#define SC16IS7XX_IIR_NO_INT_BIT (1 << 0) /* No interrupts pending */
102#define SC16IS7XX_IIR_ID_MASK 0x3e /* Mask for the interrupt ID */
103#define SC16IS7XX_IIR_THRI_SRC 0x02 /* TX holding register empty */
104#define SC16IS7XX_IIR_RDI_SRC 0x04 /* RX data interrupt */
105#define SC16IS7XX_IIR_RLSE_SRC 0x06 /* RX line status error */
106#define SC16IS7XX_IIR_RTOI_SRC 0x0c /* RX time-out interrupt */
107#define SC16IS7XX_IIR_MSI_SRC 0x00 /* Modem status interrupt
108 * - only on 75x/76x
109 */
110#define SC16IS7XX_IIR_INPIN_SRC 0x30 /* Input pin change of state
111 * - only on 75x/76x
112 */
113#define SC16IS7XX_IIR_XOFFI_SRC 0x10 /* Received Xoff */
114#define SC16IS7XX_IIR_CTSRTS_SRC 0x20 /* nCTS,nRTS change of state
115 * from active (LOW)
116 * to inactive (HIGH)
117 */
118/* LCR register bits */
119#define SC16IS7XX_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */
120#define SC16IS7XX_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1
121 *
122 * Word length bits table:
123 * 00 -> 5 bit words
124 * 01 -> 6 bit words
125 * 10 -> 7 bit words
126 * 11 -> 8 bit words
127 */
128#define SC16IS7XX_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
129 *
130 * STOP length bit table:
131 * 0 -> 1 stop bit
132 * 1 -> 1-1.5 stop bits if
133 * word length is 5,
134 * 2 stop bits otherwise
135 */
136#define SC16IS7XX_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */
137#define SC16IS7XX_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */
138#define SC16IS7XX_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */
139#define SC16IS7XX_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */
140#define SC16IS7XX_LCR_DLAB_BIT (1 << 7) /* Divisor Latch enable */
141#define SC16IS7XX_LCR_WORD_LEN_5 (0x00)
142#define SC16IS7XX_LCR_WORD_LEN_6 (0x01)
143#define SC16IS7XX_LCR_WORD_LEN_7 (0x02)
144#define SC16IS7XX_LCR_WORD_LEN_8 (0x03)
145#define SC16IS7XX_LCR_CONF_MODE_A SC16IS7XX_LCR_DLAB_BIT /* Special
146 * reg set */
147#define SC16IS7XX_LCR_CONF_MODE_B 0xBF /* Enhanced
148 * reg set */
149
150/* MCR register bits */
151#define SC16IS7XX_MCR_DTR_BIT (1 << 0) /* DTR complement
152 * - only on 75x/76x
153 */
154#define SC16IS7XX_MCR_RTS_BIT (1 << 1) /* RTS complement */
155#define SC16IS7XX_MCR_TCRTLR_BIT (1 << 2) /* TCR/TLR register enable */
156#define SC16IS7XX_MCR_LOOP_BIT (1 << 4) /* Enable loopback test mode */
157#define SC16IS7XX_MCR_XONANY_BIT (1 << 5) /* Enable Xon Any
158 * - write enabled
159 * if (EFR[4] == 1)
160 */
161#define SC16IS7XX_MCR_IRDA_BIT (1 << 6) /* Enable IrDA mode
162 * - write enabled
163 * if (EFR[4] == 1)
164 */
165#define SC16IS7XX_MCR_CLKSEL_BIT (1 << 7) /* Divide clock by 4
166 * - write enabled
167 * if (EFR[4] == 1)
168 */
169
170/* LSR register bits */
171#define SC16IS7XX_LSR_DR_BIT (1 << 0) /* Receiver data ready */
172#define SC16IS7XX_LSR_OE_BIT (1 << 1) /* Overrun Error */
173#define SC16IS7XX_LSR_PE_BIT (1 << 2) /* Parity Error */
174#define SC16IS7XX_LSR_FE_BIT (1 << 3) /* Frame Error */
175#define SC16IS7XX_LSR_BI_BIT (1 << 4) /* Break Interrupt */
176#define SC16IS7XX_LSR_BRK_ERROR_MASK 0x1E /* BI, FE, PE, OE bits */
177#define SC16IS7XX_LSR_THRE_BIT (1 << 5) /* TX holding register empty */
178#define SC16IS7XX_LSR_TEMT_BIT (1 << 6) /* Transmitter empty */
179#define SC16IS7XX_LSR_FIFOE_BIT (1 << 7) /* Fifo Error */
180
181/* MSR register bits */
182#define SC16IS7XX_MSR_DCTS_BIT (1 << 0) /* Delta CTS Clear To Send */
183#define SC16IS7XX_MSR_DDSR_BIT (1 << 1) /* Delta DSR Data Set Ready
184 * or (IO4)
185 * - only on 75x/76x
186 */
187#define SC16IS7XX_MSR_DRI_BIT (1 << 2) /* Delta RI Ring Indicator
188 * or (IO7)
189 * - only on 75x/76x
190 */
191#define SC16IS7XX_MSR_DCD_BIT (1 << 3) /* Delta CD Carrier Detect
192 * or (IO6)
193 * - only on 75x/76x
194 */
195#define SC16IS7XX_MSR_CTS_BIT (1 << 4) /* CTS */
196#define SC16IS7XX_MSR_DSR_BIT (1 << 5) /* DSR (IO4)
197 * - only on 75x/76x
198 */
199#define SC16IS7XX_MSR_RI_BIT (1 << 6) /* RI (IO7)
200 * - only on 75x/76x
201 */
202#define SC16IS7XX_MSR_CD_BIT (1 << 7) /* CD (IO6)
203 * - only on 75x/76x
204 */
205#define SC16IS7XX_MSR_DELTA_MASK 0x0F /* Any of the delta bits! */
206
207/*
208 * TCR register bits
209 * TCR trigger levels are available from 0 to 60 characters with a granularity
210 * of four.
211 * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
212 * no built-in hardware check to make sure this condition is met. Also, the TCR
213 * must be programmed with this condition before auto RTS or software flow
214 * control is enabled to avoid spurious operation of the device.
215 */
216#define SC16IS7XX_TCR_RX_HALT(words) ((((words) / 4) & 0x0f) << 0)
217#define SC16IS7XX_TCR_RX_RESUME(words) ((((words) / 4) & 0x0f) << 4)
218
219/*
220 * TLR register bits
221 * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
222 * FIFO Control Register (FCR) are used for the transmit and receive FIFO
223 * trigger levels. Trigger levels from 4 characters to 60 characters are
224 * available with a granularity of four.
225 *
226 * When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the
227 * trigger level setting defined in FCR. If TLR has non-zero trigger level value
228 * the trigger level defined in FCR is discarded. This applies to both transmit
229 * FIFO and receive FIFO trigger level setting.
230 *
231 * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
232 * default state, that is, '00'.
233 */
234#define SC16IS7XX_TLR_TX_TRIGGER(words) ((((words) / 4) & 0x0f) << 0)
235#define SC16IS7XX_TLR_RX_TRIGGER(words) ((((words) / 4) & 0x0f) << 4)
236
237/* IOControl register bits (Only 750/760) */
238#define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */
239#define SC16IS7XX_IOCONTROL_MODEM_BIT (1 << 1) /* Enable GPIO[7:4] as modem pins */
240#define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */
241
242/* EFCR register bits */
243#define SC16IS7XX_EFCR_9BIT_MODE_BIT (1 << 0) /* Enable 9-bit or Multidrop
244 * mode (RS485) */
245#define SC16IS7XX_EFCR_RXDISABLE_BIT (1 << 1) /* Disable receiver */
246#define SC16IS7XX_EFCR_TXDISABLE_BIT (1 << 2) /* Disable transmitter */
247#define SC16IS7XX_EFCR_AUTO_RS485_BIT (1 << 4) /* Auto RS485 RTS direction */
248#define SC16IS7XX_EFCR_RTS_INVERT_BIT (1 << 5) /* RTS output inversion */
249#define SC16IS7XX_EFCR_IRDA_MODE_BIT (1 << 7) /* IrDA mode
250 * 0 = rate upto 115.2 kbit/s
251 * - Only 750/760
252 * 1 = rate upto 1.152 Mbit/s
253 * - Only 760
254 */
255
256/* EFR register bits */
257#define SC16IS7XX_EFR_AUTORTS_BIT (1 << 6) /* Auto RTS flow ctrl enable */
258#define SC16IS7XX_EFR_AUTOCTS_BIT (1 << 7) /* Auto CTS flow ctrl enable */
259#define SC16IS7XX_EFR_XOFF2_DETECT_BIT (1 << 5) /* Enable Xoff2 detection */
260#define SC16IS7XX_EFR_ENABLE_BIT (1 << 4) /* Enable enhanced functions
261 * and writing to IER[7:4],
262 * FCR[5:4], MCR[7:5]
263 */
264#define SC16IS7XX_EFR_SWFLOW3_BIT (1 << 3) /* SWFLOW bit 3 */
265#define SC16IS7XX_EFR_SWFLOW2_BIT (1 << 2) /* SWFLOW bit 2
266 *
267 * SWFLOW bits 3 & 2 table:
268 * 00 -> no transmitter flow
269 * control
270 * 01 -> transmitter generates
271 * XON2 and XOFF2
272 * 10 -> transmitter generates
273 * XON1 and XOFF1
274 * 11 -> transmitter generates
275 * XON1, XON2, XOFF1 and
276 * XOFF2
277 */
278#define SC16IS7XX_EFR_SWFLOW1_BIT (1 << 1) /* SWFLOW bit 2 */
279#define SC16IS7XX_EFR_SWFLOW0_BIT (1 << 0) /* SWFLOW bit 3
280 *
281 * SWFLOW bits 3 & 2 table:
282 * 00 -> no received flow
283 * control
284 * 01 -> receiver compares
285 * XON2 and XOFF2
286 * 10 -> receiver compares
287 * XON1 and XOFF1
288 * 11 -> receiver compares
289 * XON1, XON2, XOFF1 and
290 * XOFF2
291 */
292
293/* Misc definitions */
294#define SC16IS7XX_FIFO_SIZE (64)
295#define SC16IS7XX_REG_SHIFT 2
296
297struct sc16is7xx_devtype {
298 char name[10];
299 int nr_gpio;
300 int nr_uart;
301};
302
303#define SC16IS7XX_RECONF_MD (1 << 0)
304#define SC16IS7XX_RECONF_IER (1 << 1)
305#define SC16IS7XX_RECONF_RS485 (1 << 2)
306
307struct sc16is7xx_one_config {
308 unsigned int flags;
309 u8 ier_clear;
310};
311
312struct sc16is7xx_one {
313 struct uart_port port;
314 u8 line;
315 struct kthread_work tx_work;
316 struct kthread_work reg_work;
317 struct sc16is7xx_one_config config;
318};
319
320struct sc16is7xx_port {
321 const struct sc16is7xx_devtype *devtype;
322 struct regmap *regmap;
323 struct clk *clk;
324#ifdef CONFIG_GPIOLIB
325 struct gpio_chip gpio;
326#endif
327 unsigned char buf[SC16IS7XX_FIFO_SIZE];
328 struct kthread_worker kworker;
329 struct task_struct *kworker_task;
330 struct kthread_work irq_work;
331 struct sc16is7xx_one p[0];
332};
333
334static unsigned long sc16is7xx_lines;
335
336static struct uart_driver sc16is7xx_uart = {
337 .owner = THIS_MODULE,
338 .dev_name = "ttySC",
339 .nr = SC16IS7XX_MAX_DEVS,
340};
341
342#define to_sc16is7xx_port(p,e) ((container_of((p), struct sc16is7xx_port, e)))
343#define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e)))
344
345static int sc16is7xx_line(struct uart_port *port)
346{
347 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
348
349 return one->line;
350}
351
352static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
353{
354 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
355 unsigned int val = 0;
356 const u8 line = sc16is7xx_line(port);
357
358 regmap_read(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line, &val);
359
360 return val;
361}
362
363static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
364{
365 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
366 const u8 line = sc16is7xx_line(port);
367
368 regmap_write(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line, val);
369}
370
371static void sc16is7xx_fifo_read(struct uart_port *port, unsigned int rxlen)
372{
373 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
374 const u8 line = sc16is7xx_line(port);
375 u8 addr = (SC16IS7XX_RHR_REG << SC16IS7XX_REG_SHIFT) | line;
376
377 regcache_cache_bypass(s->regmap, true);
378 regmap_raw_read(s->regmap, addr, s->buf, rxlen);
379 regcache_cache_bypass(s->regmap, false);
380}
381
382static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
383{
384 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
385 const u8 line = sc16is7xx_line(port);
386 u8 addr = (SC16IS7XX_THR_REG << SC16IS7XX_REG_SHIFT) | line;
387
388 /*
389 * Don't send zero-length data, at least on SPI it confuses the chip
390 * delivering wrong TXLVL data.
391 */
392 if (unlikely(!to_send))
393 return;
394
395 regcache_cache_bypass(s->regmap, true);
396 regmap_raw_write(s->regmap, addr, s->buf, to_send);
397 regcache_cache_bypass(s->regmap, false);
398}
399
400static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
401 u8 mask, u8 val)
402{
403 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
404 const u8 line = sc16is7xx_line(port);
405
406 regmap_update_bits(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line,
407 mask, val);
408}
409
410static int sc16is7xx_alloc_line(void)
411{
412 int i;
413
414 BUILD_BUG_ON(SC16IS7XX_MAX_DEVS > BITS_PER_LONG);
415
416 for (i = 0; i < SC16IS7XX_MAX_DEVS; i++)
417 if (!test_and_set_bit(i, &sc16is7xx_lines))
418 break;
419
420 return i;
421}
422
423static void sc16is7xx_power(struct uart_port *port, int on)
424{
425 sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
426 SC16IS7XX_IER_SLEEP_BIT,
427 on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
428}
429
430static const struct sc16is7xx_devtype sc16is74x_devtype = {
431 .name = "SC16IS74X",
432 .nr_gpio = 0,
433 .nr_uart = 1,
434};
435
436static const struct sc16is7xx_devtype sc16is750_devtype = {
437 .name = "SC16IS750",
438 .nr_gpio = 8,
439 .nr_uart = 1,
440};
441
442static const struct sc16is7xx_devtype sc16is752_devtype = {
443 .name = "SC16IS752",
444 .nr_gpio = 8,
445 .nr_uart = 2,
446};
447
448static const struct sc16is7xx_devtype sc16is760_devtype = {
449 .name = "SC16IS760",
450 .nr_gpio = 8,
451 .nr_uart = 1,
452};
453
454static const struct sc16is7xx_devtype sc16is762_devtype = {
455 .name = "SC16IS762",
456 .nr_gpio = 8,
457 .nr_uart = 2,
458};
459
460static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
461{
462 switch (reg >> SC16IS7XX_REG_SHIFT) {
463 case SC16IS7XX_RHR_REG:
464 case SC16IS7XX_IIR_REG:
465 case SC16IS7XX_LSR_REG:
466 case SC16IS7XX_MSR_REG:
467 case SC16IS7XX_TXLVL_REG:
468 case SC16IS7XX_RXLVL_REG:
469 case SC16IS7XX_IOSTATE_REG:
470 return true;
471 default:
472 break;
473 }
474
475 return false;
476}
477
478static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
479{
480 switch (reg >> SC16IS7XX_REG_SHIFT) {
481 case SC16IS7XX_RHR_REG:
482 return true;
483 default:
484 break;
485 }
486
487 return false;
488}
489
490static int sc16is7xx_set_baud(struct uart_port *port, int baud)
491{
492 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
493 u8 lcr;
494 u8 prescaler = 0;
495 unsigned long clk = port->uartclk, div = clk / 16 / baud;
496
497 if (div > 0xffff) {
498 prescaler = SC16IS7XX_MCR_CLKSEL_BIT;
499 div /= 4;
500 }
501
502 lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
503
504 /* Open the LCR divisors for configuration */
505 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
506 SC16IS7XX_LCR_CONF_MODE_B);
507
508 /* Enable enhanced features */
509 regcache_cache_bypass(s->regmap, true);
510 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG,
511 SC16IS7XX_EFR_ENABLE_BIT);
512 regcache_cache_bypass(s->regmap, false);
513
514 /* Put LCR back to the normal mode */
515 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
516
517 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
518 SC16IS7XX_MCR_CLKSEL_BIT,
519 prescaler);
520
521 /* Open the LCR divisors for configuration */
522 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
523 SC16IS7XX_LCR_CONF_MODE_A);
524
525 /* Write the new divisor */
526 regcache_cache_bypass(s->regmap, true);
527 sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
528 sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
529 regcache_cache_bypass(s->regmap, false);
530
531 /* Put LCR back to the normal mode */
532 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
533
534 return DIV_ROUND_CLOSEST(clk / 16, div);
535}
536
537static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
538 unsigned int iir)
539{
540 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
541 unsigned int lsr = 0, ch, flag, bytes_read, i;
542 bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
543
544 if (unlikely(rxlen >= sizeof(s->buf))) {
545 dev_warn_ratelimited(port->dev,
546 "ttySC%i: Possible RX FIFO overrun: %d\n",
547 port->line, rxlen);
548 port->icount.buf_overrun++;
549 /* Ensure sanity of RX level */
550 rxlen = sizeof(s->buf);
551 }
552
553 while (rxlen) {
554 /* Only read lsr if there are possible errors in FIFO */
555 if (read_lsr) {
556 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
557 if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
558 read_lsr = false; /* No errors left in FIFO */
559 } else
560 lsr = 0;
561
562 if (read_lsr) {
563 s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
564 bytes_read = 1;
565 } else {
566 sc16is7xx_fifo_read(port, rxlen);
567 bytes_read = rxlen;
568 }
569
570 lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
571
572 port->icount.rx++;
573 flag = TTY_NORMAL;
574
575 if (unlikely(lsr)) {
576 if (lsr & SC16IS7XX_LSR_BI_BIT) {
577 port->icount.brk++;
578 if (uart_handle_break(port))
579 continue;
580 } else if (lsr & SC16IS7XX_LSR_PE_BIT)
581 port->icount.parity++;
582 else if (lsr & SC16IS7XX_LSR_FE_BIT)
583 port->icount.frame++;
584 else if (lsr & SC16IS7XX_LSR_OE_BIT)
585 port->icount.overrun++;
586
587 lsr &= port->read_status_mask;
588 if (lsr & SC16IS7XX_LSR_BI_BIT)
589 flag = TTY_BREAK;
590 else if (lsr & SC16IS7XX_LSR_PE_BIT)
591 flag = TTY_PARITY;
592 else if (lsr & SC16IS7XX_LSR_FE_BIT)
593 flag = TTY_FRAME;
594 else if (lsr & SC16IS7XX_LSR_OE_BIT)
595 flag = TTY_OVERRUN;
596 }
597
598 for (i = 0; i < bytes_read; ++i) {
599 ch = s->buf[i];
600 if (uart_handle_sysrq_char(port, ch))
601 continue;
602
603 if (lsr & port->ignore_status_mask)
604 continue;
605
606 uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
607 flag);
608 }
609 rxlen -= bytes_read;
610 }
611
612 tty_flip_buffer_push(&port->state->port);
613}
614
615static void sc16is7xx_handle_tx(struct uart_port *port)
616{
617 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
618 struct circ_buf *xmit = &port->state->xmit;
619 unsigned int txlen, to_send, i;
620
621 if (unlikely(port->x_char)) {
622 sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
623 port->icount.tx++;
624 port->x_char = 0;
625 return;
626 }
627
628 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
629 return;
630
631 /* Get length of data pending in circular buffer */
632 to_send = uart_circ_chars_pending(xmit);
633 if (likely(to_send)) {
634 /* Limit to size of TX FIFO */
635 txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
636 if (txlen > SC16IS7XX_FIFO_SIZE) {
637 dev_err_ratelimited(port->dev,
638 "chip reports %d free bytes in TX fifo, but it only has %d",
639 txlen, SC16IS7XX_FIFO_SIZE);
640 txlen = 0;
641 }
642 to_send = (to_send > txlen) ? txlen : to_send;
643
644 /* Add data to send */
645 port->icount.tx += to_send;
646
647 /* Convert to linear buffer */
648 for (i = 0; i < to_send; ++i) {
649 s->buf[i] = xmit->buf[xmit->tail];
650 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
651 }
652
653 sc16is7xx_fifo_write(port, to_send);
654 }
655
656 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
657 uart_write_wakeup(port);
658}
659
660static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
661{
662 struct uart_port *port = &s->p[portno].port;
663
664 do {
665 unsigned int iir, rxlen;
666
667 iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
668 if (iir & SC16IS7XX_IIR_NO_INT_BIT)
669 break;
670
671 iir &= SC16IS7XX_IIR_ID_MASK;
672
673 switch (iir) {
674 case SC16IS7XX_IIR_RDI_SRC:
675 case SC16IS7XX_IIR_RLSE_SRC:
676 case SC16IS7XX_IIR_RTOI_SRC:
677 case SC16IS7XX_IIR_XOFFI_SRC:
678 rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
679 if (rxlen)
680 sc16is7xx_handle_rx(port, rxlen, iir);
681 break;
682 case SC16IS7XX_IIR_THRI_SRC:
683 sc16is7xx_handle_tx(port);
684 break;
685 default:
686 dev_err_ratelimited(port->dev,
687 "ttySC%i: Unexpected interrupt: %x",
688 port->line, iir);
689 break;
690 }
691 } while (1);
692}
693
694static void sc16is7xx_ist(struct kthread_work *ws)
695{
696 struct sc16is7xx_port *s = to_sc16is7xx_port(ws, irq_work);
697 int i;
698
699 for (i = 0; i < s->devtype->nr_uart; ++i)
700 sc16is7xx_port_irq(s, i);
701}
702
703static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
704{
705 struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
706
707 kthread_queue_work(&s->kworker, &s->irq_work);
708
709 return IRQ_HANDLED;
710}
711
712static void sc16is7xx_tx_proc(struct kthread_work *ws)
713{
714 struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
715
716 if ((port->rs485.flags & SER_RS485_ENABLED) &&
717 (port->rs485.delay_rts_before_send > 0))
718 msleep(port->rs485.delay_rts_before_send);
719
720 sc16is7xx_handle_tx(port);
721}
722
723static void sc16is7xx_reconf_rs485(struct uart_port *port)
724{
725 const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
726 SC16IS7XX_EFCR_RTS_INVERT_BIT;
727 u32 efcr = 0;
728 struct serial_rs485 *rs485 = &port->rs485;
729 unsigned long irqflags;
730
731 spin_lock_irqsave(&port->lock, irqflags);
732 if (rs485->flags & SER_RS485_ENABLED) {
733 efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT;
734
735 if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
736 efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
737 }
738 spin_unlock_irqrestore(&port->lock, irqflags);
739
740 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
741}
742
743static void sc16is7xx_reg_proc(struct kthread_work *ws)
744{
745 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
746 struct sc16is7xx_one_config config;
747 unsigned long irqflags;
748
749 spin_lock_irqsave(&one->port.lock, irqflags);
750 config = one->config;
751 memset(&one->config, 0, sizeof(one->config));
752 spin_unlock_irqrestore(&one->port.lock, irqflags);
753
754 if (config.flags & SC16IS7XX_RECONF_MD) {
755 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
756 SC16IS7XX_MCR_LOOP_BIT,
757 (one->port.mctrl & TIOCM_LOOP) ?
758 SC16IS7XX_MCR_LOOP_BIT : 0);
759 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
760 SC16IS7XX_MCR_RTS_BIT,
761 (one->port.mctrl & TIOCM_RTS) ?
762 SC16IS7XX_MCR_RTS_BIT : 0);
763 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
764 SC16IS7XX_MCR_DTR_BIT,
765 (one->port.mctrl & TIOCM_DTR) ?
766 SC16IS7XX_MCR_DTR_BIT : 0);
767 }
768 if (config.flags & SC16IS7XX_RECONF_IER)
769 sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
770 config.ier_clear, 0);
771
772 if (config.flags & SC16IS7XX_RECONF_RS485)
773 sc16is7xx_reconf_rs485(&one->port);
774}
775
776static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
777{
778 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
779 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
780
781 one->config.flags |= SC16IS7XX_RECONF_IER;
782 one->config.ier_clear |= bit;
783 kthread_queue_work(&s->kworker, &one->reg_work);
784}
785
786static void sc16is7xx_stop_tx(struct uart_port *port)
787{
788 sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
789}
790
791static void sc16is7xx_stop_rx(struct uart_port *port)
792{
793 sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
794}
795
796static void sc16is7xx_start_tx(struct uart_port *port)
797{
798 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
799 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
800
801 kthread_queue_work(&s->kworker, &one->tx_work);
802}
803
804static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
805{
806 unsigned int lsr;
807
808 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
809
810 return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
811}
812
813static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
814{
815 /* DCD and DSR are not wired and CTS/RTS is handled automatically
816 * so just indicate DSR and CAR asserted
817 */
818 return TIOCM_DSR | TIOCM_CAR;
819}
820
821static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
822{
823 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
824 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
825
826 one->config.flags |= SC16IS7XX_RECONF_MD;
827 kthread_queue_work(&s->kworker, &one->reg_work);
828}
829
830static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
831{
832 sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
833 SC16IS7XX_LCR_TXBREAK_BIT,
834 break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
835}
836
837static void sc16is7xx_set_termios(struct uart_port *port,
838 struct ktermios *termios,
839 struct ktermios *old)
840{
841 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
842 unsigned int lcr, flow = 0;
843 int baud;
844
845 /* Mask termios capabilities we don't support */
846 termios->c_cflag &= ~CMSPAR;
847
848 /* Word size */
849 switch (termios->c_cflag & CSIZE) {
850 case CS5:
851 lcr = SC16IS7XX_LCR_WORD_LEN_5;
852 break;
853 case CS6:
854 lcr = SC16IS7XX_LCR_WORD_LEN_6;
855 break;
856 case CS7:
857 lcr = SC16IS7XX_LCR_WORD_LEN_7;
858 break;
859 case CS8:
860 lcr = SC16IS7XX_LCR_WORD_LEN_8;
861 break;
862 default:
863 lcr = SC16IS7XX_LCR_WORD_LEN_8;
864 termios->c_cflag &= ~CSIZE;
865 termios->c_cflag |= CS8;
866 break;
867 }
868
869 /* Parity */
870 if (termios->c_cflag & PARENB) {
871 lcr |= SC16IS7XX_LCR_PARITY_BIT;
872 if (!(termios->c_cflag & PARODD))
873 lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
874 }
875
876 /* Stop bits */
877 if (termios->c_cflag & CSTOPB)
878 lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
879
880 /* Set read status mask */
881 port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
882 if (termios->c_iflag & INPCK)
883 port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
884 SC16IS7XX_LSR_FE_BIT;
885 if (termios->c_iflag & (BRKINT | PARMRK))
886 port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
887
888 /* Set status ignore mask */
889 port->ignore_status_mask = 0;
890 if (termios->c_iflag & IGNBRK)
891 port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
892 if (!(termios->c_cflag & CREAD))
893 port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
894
895 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
896 SC16IS7XX_LCR_CONF_MODE_B);
897
898 /* Configure flow control */
899 regcache_cache_bypass(s->regmap, true);
900 sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
901 sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
902 if (termios->c_cflag & CRTSCTS)
903 flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
904 SC16IS7XX_EFR_AUTORTS_BIT;
905 if (termios->c_iflag & IXON)
906 flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
907 if (termios->c_iflag & IXOFF)
908 flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
909
910 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, flow);
911 regcache_cache_bypass(s->regmap, false);
912
913 /* Update LCR register */
914 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
915
916 /* Get baud rate generator configuration */
917 baud = uart_get_baud_rate(port, termios, old,
918 port->uartclk / 16 / 4 / 0xffff,
919 port->uartclk / 16);
920
921 /* Setup baudrate generator */
922 baud = sc16is7xx_set_baud(port, baud);
923
924 /* Update timeout according to new baud rate */
925 uart_update_timeout(port, termios->c_cflag, baud);
926}
927
928static int sc16is7xx_config_rs485(struct uart_port *port,
929 struct serial_rs485 *rs485)
930{
931 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
932 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
933
934 if (rs485->flags & SER_RS485_ENABLED) {
935 bool rts_during_rx, rts_during_tx;
936
937 rts_during_rx = rs485->flags & SER_RS485_RTS_AFTER_SEND;
938 rts_during_tx = rs485->flags & SER_RS485_RTS_ON_SEND;
939
940 if (rts_during_rx == rts_during_tx)
941 dev_err(port->dev,
942 "unsupported RTS signalling on_send:%d after_send:%d - exactly one of RS485 RTS flags should be set\n",
943 rts_during_tx, rts_during_rx);
944
945 /*
946 * RTS signal is handled by HW, it's timing can't be influenced.
947 * However, it's sometimes useful to delay TX even without RTS
948 * control therefore we try to handle .delay_rts_before_send.
949 */
950 if (rs485->delay_rts_after_send)
951 return -EINVAL;
952 }
953
954 port->rs485 = *rs485;
955 one->config.flags |= SC16IS7XX_RECONF_RS485;
956 kthread_queue_work(&s->kworker, &one->reg_work);
957
958 return 0;
959}
960
961static int sc16is7xx_startup(struct uart_port *port)
962{
963 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
964 unsigned int val;
965
966 sc16is7xx_power(port, 1);
967
968 /* Reset FIFOs*/
969 val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
970 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
971 udelay(5);
972 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
973 SC16IS7XX_FCR_FIFO_BIT);
974
975 /* Enable EFR */
976 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
977 SC16IS7XX_LCR_CONF_MODE_B);
978
979 regcache_cache_bypass(s->regmap, true);
980
981 /* Enable write access to enhanced features and internal clock div */
982 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG,
983 SC16IS7XX_EFR_ENABLE_BIT);
984
985 /* Enable TCR/TLR */
986 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
987 SC16IS7XX_MCR_TCRTLR_BIT,
988 SC16IS7XX_MCR_TCRTLR_BIT);
989
990 /* Configure flow control levels */
991 /* Flow control halt level 48, resume level 24 */
992 sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
993 SC16IS7XX_TCR_RX_RESUME(24) |
994 SC16IS7XX_TCR_RX_HALT(48));
995
996 regcache_cache_bypass(s->regmap, false);
997
998 /* Now, initialize the UART */
999 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
1000
1001 /* Enable the Rx and Tx FIFO */
1002 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1003 SC16IS7XX_EFCR_RXDISABLE_BIT |
1004 SC16IS7XX_EFCR_TXDISABLE_BIT,
1005 0);
1006
1007 /* Enable RX, TX interrupts */
1008 val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_THRI_BIT;
1009 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1010
1011 return 0;
1012}
1013
1014static void sc16is7xx_shutdown(struct uart_port *port)
1015{
1016 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1017
1018 /* Disable all interrupts */
1019 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1020 /* Disable TX/RX */
1021 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1022 SC16IS7XX_EFCR_RXDISABLE_BIT |
1023 SC16IS7XX_EFCR_TXDISABLE_BIT,
1024 SC16IS7XX_EFCR_RXDISABLE_BIT |
1025 SC16IS7XX_EFCR_TXDISABLE_BIT);
1026
1027 sc16is7xx_power(port, 0);
1028
1029 kthread_flush_worker(&s->kworker);
1030}
1031
1032static const char *sc16is7xx_type(struct uart_port *port)
1033{
1034 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1035
1036 return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1037}
1038
1039static int sc16is7xx_request_port(struct uart_port *port)
1040{
1041 /* Do nothing */
1042 return 0;
1043}
1044
1045static void sc16is7xx_config_port(struct uart_port *port, int flags)
1046{
1047 if (flags & UART_CONFIG_TYPE)
1048 port->type = PORT_SC16IS7XX;
1049}
1050
1051static int sc16is7xx_verify_port(struct uart_port *port,
1052 struct serial_struct *s)
1053{
1054 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1055 return -EINVAL;
1056 if (s->irq != port->irq)
1057 return -EINVAL;
1058
1059 return 0;
1060}
1061
1062static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1063 unsigned int oldstate)
1064{
1065 sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1066}
1067
1068static void sc16is7xx_null_void(struct uart_port *port)
1069{
1070 /* Do nothing */
1071}
1072
1073static const struct uart_ops sc16is7xx_ops = {
1074 .tx_empty = sc16is7xx_tx_empty,
1075 .set_mctrl = sc16is7xx_set_mctrl,
1076 .get_mctrl = sc16is7xx_get_mctrl,
1077 .stop_tx = sc16is7xx_stop_tx,
1078 .start_tx = sc16is7xx_start_tx,
1079 .stop_rx = sc16is7xx_stop_rx,
1080 .break_ctl = sc16is7xx_break_ctl,
1081 .startup = sc16is7xx_startup,
1082 .shutdown = sc16is7xx_shutdown,
1083 .set_termios = sc16is7xx_set_termios,
1084 .type = sc16is7xx_type,
1085 .request_port = sc16is7xx_request_port,
1086 .release_port = sc16is7xx_null_void,
1087 .config_port = sc16is7xx_config_port,
1088 .verify_port = sc16is7xx_verify_port,
1089 .pm = sc16is7xx_pm,
1090};
1091
1092#ifdef CONFIG_GPIOLIB
1093static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1094{
1095 unsigned int val;
1096 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1097 struct uart_port *port = &s->p[0].port;
1098
1099 val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1100
1101 return !!(val & BIT(offset));
1102}
1103
1104static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1105{
1106 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1107 struct uart_port *port = &s->p[0].port;
1108
1109 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1110 val ? BIT(offset) : 0);
1111}
1112
1113static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1114 unsigned offset)
1115{
1116 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1117 struct uart_port *port = &s->p[0].port;
1118
1119 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1120
1121 return 0;
1122}
1123
1124static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1125 unsigned offset, int val)
1126{
1127 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1128 struct uart_port *port = &s->p[0].port;
1129 u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1130
1131 if (val)
1132 state |= BIT(offset);
1133 else
1134 state &= ~BIT(offset);
1135 sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
1136 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1137 BIT(offset));
1138
1139 return 0;
1140}
1141#endif
1142
1143static int sc16is7xx_probe(struct device *dev,
1144 const struct sc16is7xx_devtype *devtype,
1145 struct regmap *regmap, int irq, unsigned long flags)
1146{
1147 struct sched_param sched_param = { .sched_priority = MAX_RT_PRIO / 2 };
1148 unsigned long freq, *pfreq = dev_get_platdata(dev);
1149 int i, ret;
1150 struct sc16is7xx_port *s;
1151
1152 if (IS_ERR(regmap))
1153 return PTR_ERR(regmap);
1154
1155 /* Alloc port structure */
1156 s = devm_kzalloc(dev, sizeof(*s) +
1157 sizeof(struct sc16is7xx_one) * devtype->nr_uart,
1158 GFP_KERNEL);
1159 if (!s) {
1160 dev_err(dev, "Error allocating port structure\n");
1161 return -ENOMEM;
1162 }
1163
1164 s->clk = devm_clk_get(dev, NULL);
1165 if (IS_ERR(s->clk)) {
1166 if (pfreq)
1167 freq = *pfreq;
1168 else
1169 return PTR_ERR(s->clk);
1170 } else {
1171 clk_prepare_enable(s->clk);
1172 freq = clk_get_rate(s->clk);
1173 }
1174
1175 s->regmap = regmap;
1176 s->devtype = devtype;
1177 dev_set_drvdata(dev, s);
1178
1179 kthread_init_worker(&s->kworker);
1180 kthread_init_work(&s->irq_work, sc16is7xx_ist);
1181 s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1182 "sc16is7xx");
1183 if (IS_ERR(s->kworker_task)) {
1184 ret = PTR_ERR(s->kworker_task);
1185 goto out_clk;
1186 }
1187 sched_setscheduler(s->kworker_task, SCHED_FIFO, &sched_param);
1188
1189#ifdef CONFIG_GPIOLIB
1190 if (devtype->nr_gpio) {
1191 /* Setup GPIO cotroller */
1192 s->gpio.owner = THIS_MODULE;
1193 s->gpio.parent = dev;
1194 s->gpio.label = dev_name(dev);
1195 s->gpio.direction_input = sc16is7xx_gpio_direction_input;
1196 s->gpio.get = sc16is7xx_gpio_get;
1197 s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1198 s->gpio.set = sc16is7xx_gpio_set;
1199 s->gpio.base = -1;
1200 s->gpio.ngpio = devtype->nr_gpio;
1201 s->gpio.can_sleep = 1;
1202 ret = gpiochip_add_data(&s->gpio, s);
1203 if (ret)
1204 goto out_thread;
1205 }
1206#endif
1207
1208 /* reset device, purging any pending irq / data */
1209 regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
1210 SC16IS7XX_IOCONTROL_SRESET_BIT);
1211
1212 for (i = 0; i < devtype->nr_uart; ++i) {
1213 s->p[i].line = i;
1214 /* Initialize port data */
1215 s->p[i].port.dev = dev;
1216 s->p[i].port.irq = irq;
1217 s->p[i].port.type = PORT_SC16IS7XX;
1218 s->p[i].port.fifosize = SC16IS7XX_FIFO_SIZE;
1219 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1220 s->p[i].port.iotype = UPIO_PORT;
1221 s->p[i].port.uartclk = freq;
1222 s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1223 s->p[i].port.ops = &sc16is7xx_ops;
1224 s->p[i].port.line = sc16is7xx_alloc_line();
1225 if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
1226 ret = -ENOMEM;
1227 goto out_ports;
1228 }
1229
1230 /* Disable all interrupts */
1231 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1232 /* Disable TX/RX */
1233 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1234 SC16IS7XX_EFCR_RXDISABLE_BIT |
1235 SC16IS7XX_EFCR_TXDISABLE_BIT);
1236 /* Initialize kthread work structs */
1237 kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1238 kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1239 /* Register port */
1240 uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1241
1242 /* Enable EFR */
1243 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
1244 SC16IS7XX_LCR_CONF_MODE_B);
1245
1246 regcache_cache_bypass(s->regmap, true);
1247
1248 /* Enable write access to enhanced features */
1249 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
1250 SC16IS7XX_EFR_ENABLE_BIT);
1251
1252 regcache_cache_bypass(s->regmap, false);
1253
1254 /* Restore access to general registers */
1255 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
1256
1257 /* Go to suspend mode */
1258 sc16is7xx_power(&s->p[i].port, 0);
1259 }
1260
1261 /* Setup interrupt */
1262 ret = devm_request_irq(dev, irq, sc16is7xx_irq,
1263 flags, dev_name(dev), s);
1264 if (!ret)
1265 return 0;
1266
1267out_ports:
1268 for (i--; i >= 0; i--) {
1269 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1270 clear_bit(s->p[i].port.line, &sc16is7xx_lines);
1271 }
1272
1273#ifdef CONFIG_GPIOLIB
1274 if (devtype->nr_gpio)
1275 gpiochip_remove(&s->gpio);
1276
1277out_thread:
1278#endif
1279 kthread_stop(s->kworker_task);
1280
1281out_clk:
1282 if (!IS_ERR(s->clk))
1283 clk_disable_unprepare(s->clk);
1284
1285 return ret;
1286}
1287
1288static int sc16is7xx_remove(struct device *dev)
1289{
1290 struct sc16is7xx_port *s = dev_get_drvdata(dev);
1291 int i;
1292
1293#ifdef CONFIG_GPIOLIB
1294 if (s->devtype->nr_gpio)
1295 gpiochip_remove(&s->gpio);
1296#endif
1297
1298 for (i = 0; i < s->devtype->nr_uart; i++) {
1299 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1300 clear_bit(s->p[i].port.line, &sc16is7xx_lines);
1301 sc16is7xx_power(&s->p[i].port, 0);
1302 }
1303
1304 kthread_flush_worker(&s->kworker);
1305 kthread_stop(s->kworker_task);
1306
1307 if (!IS_ERR(s->clk))
1308 clk_disable_unprepare(s->clk);
1309
1310 return 0;
1311}
1312
1313static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1314 { .compatible = "nxp,sc16is740", .data = &sc16is74x_devtype, },
1315 { .compatible = "nxp,sc16is741", .data = &sc16is74x_devtype, },
1316 { .compatible = "nxp,sc16is750", .data = &sc16is750_devtype, },
1317 { .compatible = "nxp,sc16is752", .data = &sc16is752_devtype, },
1318 { .compatible = "nxp,sc16is760", .data = &sc16is760_devtype, },
1319 { .compatible = "nxp,sc16is762", .data = &sc16is762_devtype, },
1320 { }
1321};
1322MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1323
1324static struct regmap_config regcfg = {
1325 .reg_bits = 7,
1326 .pad_bits = 1,
1327 .val_bits = 8,
1328 .cache_type = REGCACHE_RBTREE,
1329 .volatile_reg = sc16is7xx_regmap_volatile,
1330 .precious_reg = sc16is7xx_regmap_precious,
1331};
1332
1333#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1334static int sc16is7xx_spi_probe(struct spi_device *spi)
1335{
1336 const struct sc16is7xx_devtype *devtype;
1337 unsigned long flags = 0;
1338 struct regmap *regmap;
1339 int ret;
1340
1341 /* Setup SPI bus */
1342 spi->bits_per_word = 8;
1343 /* only supports mode 0 on SC16IS762 */
1344 spi->mode = spi->mode ? : SPI_MODE_0;
1345 spi->max_speed_hz = spi->max_speed_hz ? : 15000000;
1346 ret = spi_setup(spi);
1347 if (ret)
1348 return ret;
1349
1350 if (spi->dev.of_node) {
1351 const struct of_device_id *of_id =
1352 of_match_device(sc16is7xx_dt_ids, &spi->dev);
1353
1354 if (!of_id)
1355 return -ENODEV;
1356
1357 devtype = (struct sc16is7xx_devtype *)of_id->data;
1358 } else {
1359 const struct spi_device_id *id_entry = spi_get_device_id(spi);
1360
1361 devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
1362 flags = IRQF_TRIGGER_FALLING;
1363 }
1364
1365 regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1366 (devtype->nr_uart - 1);
1367 regmap = devm_regmap_init_spi(spi, ®cfg);
1368
1369 return sc16is7xx_probe(&spi->dev, devtype, regmap, spi->irq, flags);
1370}
1371
1372static int sc16is7xx_spi_remove(struct spi_device *spi)
1373{
1374 return sc16is7xx_remove(&spi->dev);
1375}
1376
1377static const struct spi_device_id sc16is7xx_spi_id_table[] = {
1378 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1379 { "sc16is740", (kernel_ulong_t)&sc16is74x_devtype, },
1380 { "sc16is741", (kernel_ulong_t)&sc16is74x_devtype, },
1381 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1382 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1383 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1384 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1385 { }
1386};
1387
1388MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
1389
1390static struct spi_driver sc16is7xx_spi_uart_driver = {
1391 .driver = {
1392 .name = SC16IS7XX_NAME,
1393 .of_match_table = of_match_ptr(sc16is7xx_dt_ids),
1394 },
1395 .probe = sc16is7xx_spi_probe,
1396 .remove = sc16is7xx_spi_remove,
1397 .id_table = sc16is7xx_spi_id_table,
1398};
1399
1400MODULE_ALIAS("spi:sc16is7xx");
1401#endif
1402
1403#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1404static int sc16is7xx_i2c_probe(struct i2c_client *i2c,
1405 const struct i2c_device_id *id)
1406{
1407 const struct sc16is7xx_devtype *devtype;
1408 unsigned long flags = 0;
1409 struct regmap *regmap;
1410
1411 if (i2c->dev.of_node) {
1412 const struct of_device_id *of_id =
1413 of_match_device(sc16is7xx_dt_ids, &i2c->dev);
1414
1415 if (!of_id)
1416 return -ENODEV;
1417
1418 devtype = (struct sc16is7xx_devtype *)of_id->data;
1419 } else {
1420 devtype = (struct sc16is7xx_devtype *)id->driver_data;
1421 flags = IRQF_TRIGGER_FALLING;
1422 }
1423
1424 regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1425 (devtype->nr_uart - 1);
1426 regmap = devm_regmap_init_i2c(i2c, ®cfg);
1427
1428 return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq, flags);
1429}
1430
1431static int sc16is7xx_i2c_remove(struct i2c_client *client)
1432{
1433 return sc16is7xx_remove(&client->dev);
1434}
1435
1436static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
1437 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1438 { "sc16is740", (kernel_ulong_t)&sc16is74x_devtype, },
1439 { "sc16is741", (kernel_ulong_t)&sc16is74x_devtype, },
1440 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1441 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1442 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1443 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1444 { }
1445};
1446MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
1447
1448static struct i2c_driver sc16is7xx_i2c_uart_driver = {
1449 .driver = {
1450 .name = SC16IS7XX_NAME,
1451 .of_match_table = of_match_ptr(sc16is7xx_dt_ids),
1452 },
1453 .probe = sc16is7xx_i2c_probe,
1454 .remove = sc16is7xx_i2c_remove,
1455 .id_table = sc16is7xx_i2c_id_table,
1456};
1457
1458#endif
1459
1460static int __init sc16is7xx_init(void)
1461{
1462 int ret;
1463
1464 ret = uart_register_driver(&sc16is7xx_uart);
1465 if (ret) {
1466 pr_err("Registering UART driver failed\n");
1467 return ret;
1468 }
1469
1470#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1471 ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
1472 if (ret < 0) {
1473 pr_err("failed to init sc16is7xx i2c --> %d\n", ret);
1474 return ret;
1475 }
1476#endif
1477
1478#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1479 ret = spi_register_driver(&sc16is7xx_spi_uart_driver);
1480 if (ret < 0) {
1481 pr_err("failed to init sc16is7xx spi --> %d\n", ret);
1482 return ret;
1483 }
1484#endif
1485 return ret;
1486}
1487module_init(sc16is7xx_init);
1488
1489static void __exit sc16is7xx_exit(void)
1490{
1491#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1492 i2c_del_driver(&sc16is7xx_i2c_uart_driver);
1493#endif
1494
1495#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1496 spi_unregister_driver(&sc16is7xx_spi_uart_driver);
1497#endif
1498 uart_unregister_driver(&sc16is7xx_uart);
1499}
1500module_exit(sc16is7xx_exit);
1501
1502MODULE_LICENSE("GPL");
1503MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1504MODULE_DESCRIPTION("SC16IS7XX serial driver");