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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/*
2 * SC16IS7xx tty serial driver - Copyright (C) 2014 GridPoint
3 * Author: Jon Ringle <jringle@gridpoint.com>
4 *
5 * Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/bitops.h>
17#include <linux/clk.h>
18#include <linux/delay.h>
19#include <linux/device.h>
20#include <linux/gpio.h>
21#include <linux/i2c.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/regmap.h>
26#include <linux/serial_core.h>
27#include <linux/serial.h>
28#include <linux/tty.h>
29#include <linux/tty_flip.h>
30#include <linux/spi/spi.h>
31#include <linux/uaccess.h>
32
33#define SC16IS7XX_NAME "sc16is7xx"
34#define SC16IS7XX_MAX_DEVS 8
35
36/* SC16IS7XX register definitions */
37#define SC16IS7XX_RHR_REG (0x00) /* RX FIFO */
38#define SC16IS7XX_THR_REG (0x00) /* TX FIFO */
39#define SC16IS7XX_IER_REG (0x01) /* Interrupt enable */
40#define SC16IS7XX_IIR_REG (0x02) /* Interrupt Identification */
41#define SC16IS7XX_FCR_REG (0x02) /* FIFO control */
42#define SC16IS7XX_LCR_REG (0x03) /* Line Control */
43#define SC16IS7XX_MCR_REG (0x04) /* Modem Control */
44#define SC16IS7XX_LSR_REG (0x05) /* Line Status */
45#define SC16IS7XX_MSR_REG (0x06) /* Modem Status */
46#define SC16IS7XX_SPR_REG (0x07) /* Scratch Pad */
47#define SC16IS7XX_TXLVL_REG (0x08) /* TX FIFO level */
48#define SC16IS7XX_RXLVL_REG (0x09) /* RX FIFO level */
49#define SC16IS7XX_IODIR_REG (0x0a) /* I/O Direction
50 * - only on 75x/76x
51 */
52#define SC16IS7XX_IOSTATE_REG (0x0b) /* I/O State
53 * - only on 75x/76x
54 */
55#define SC16IS7XX_IOINTENA_REG (0x0c) /* I/O Interrupt Enable
56 * - only on 75x/76x
57 */
58#define SC16IS7XX_IOCONTROL_REG (0x0e) /* I/O Control
59 * - only on 75x/76x
60 */
61#define SC16IS7XX_EFCR_REG (0x0f) /* Extra Features Control */
62
63/* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
64#define SC16IS7XX_TCR_REG (0x06) /* Transmit control */
65#define SC16IS7XX_TLR_REG (0x07) /* Trigger level */
66
67/* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
68#define SC16IS7XX_DLL_REG (0x00) /* Divisor Latch Low */
69#define SC16IS7XX_DLH_REG (0x01) /* Divisor Latch High */
70
71/* Enhanced Register set: Only if (LCR == 0xBF) */
72#define SC16IS7XX_EFR_REG (0x02) /* Enhanced Features */
73#define SC16IS7XX_XON1_REG (0x04) /* Xon1 word */
74#define SC16IS7XX_XON2_REG (0x05) /* Xon2 word */
75#define SC16IS7XX_XOFF1_REG (0x06) /* Xoff1 word */
76#define SC16IS7XX_XOFF2_REG (0x07) /* Xoff2 word */
77
78/* IER register bits */
79#define SC16IS7XX_IER_RDI_BIT (1 << 0) /* Enable RX data interrupt */
80#define SC16IS7XX_IER_THRI_BIT (1 << 1) /* Enable TX holding register
81 * interrupt */
82#define SC16IS7XX_IER_RLSI_BIT (1 << 2) /* Enable RX line status
83 * interrupt */
84#define SC16IS7XX_IER_MSI_BIT (1 << 3) /* Enable Modem status
85 * interrupt */
86
87/* IER register bits - write only if (EFR[4] == 1) */
88#define SC16IS7XX_IER_SLEEP_BIT (1 << 4) /* Enable Sleep mode */
89#define SC16IS7XX_IER_XOFFI_BIT (1 << 5) /* Enable Xoff interrupt */
90#define SC16IS7XX_IER_RTSI_BIT (1 << 6) /* Enable nRTS interrupt */
91#define SC16IS7XX_IER_CTSI_BIT (1 << 7) /* Enable nCTS interrupt */
92
93/* FCR register bits */
94#define SC16IS7XX_FCR_FIFO_BIT (1 << 0) /* Enable FIFO */
95#define SC16IS7XX_FCR_RXRESET_BIT (1 << 1) /* Reset RX FIFO */
96#define SC16IS7XX_FCR_TXRESET_BIT (1 << 2) /* Reset TX FIFO */
97#define SC16IS7XX_FCR_RXLVLL_BIT (1 << 6) /* RX Trigger level LSB */
98#define SC16IS7XX_FCR_RXLVLH_BIT (1 << 7) /* RX Trigger level MSB */
99
100/* FCR register bits - write only if (EFR[4] == 1) */
101#define SC16IS7XX_FCR_TXLVLL_BIT (1 << 4) /* TX Trigger level LSB */
102#define SC16IS7XX_FCR_TXLVLH_BIT (1 << 5) /* TX Trigger level MSB */
103
104/* IIR register bits */
105#define SC16IS7XX_IIR_NO_INT_BIT (1 << 0) /* No interrupts pending */
106#define SC16IS7XX_IIR_ID_MASK 0x3e /* Mask for the interrupt ID */
107#define SC16IS7XX_IIR_THRI_SRC 0x02 /* TX holding register empty */
108#define SC16IS7XX_IIR_RDI_SRC 0x04 /* RX data interrupt */
109#define SC16IS7XX_IIR_RLSE_SRC 0x06 /* RX line status error */
110#define SC16IS7XX_IIR_RTOI_SRC 0x0c /* RX time-out interrupt */
111#define SC16IS7XX_IIR_MSI_SRC 0x00 /* Modem status interrupt
112 * - only on 75x/76x
113 */
114#define SC16IS7XX_IIR_INPIN_SRC 0x30 /* Input pin change of state
115 * - only on 75x/76x
116 */
117#define SC16IS7XX_IIR_XOFFI_SRC 0x10 /* Received Xoff */
118#define SC16IS7XX_IIR_CTSRTS_SRC 0x20 /* nCTS,nRTS change of state
119 * from active (LOW)
120 * to inactive (HIGH)
121 */
122/* LCR register bits */
123#define SC16IS7XX_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */
124#define SC16IS7XX_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1
125 *
126 * Word length bits table:
127 * 00 -> 5 bit words
128 * 01 -> 6 bit words
129 * 10 -> 7 bit words
130 * 11 -> 8 bit words
131 */
132#define SC16IS7XX_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
133 *
134 * STOP length bit table:
135 * 0 -> 1 stop bit
136 * 1 -> 1-1.5 stop bits if
137 * word length is 5,
138 * 2 stop bits otherwise
139 */
140#define SC16IS7XX_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */
141#define SC16IS7XX_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */
142#define SC16IS7XX_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */
143#define SC16IS7XX_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */
144#define SC16IS7XX_LCR_DLAB_BIT (1 << 7) /* Divisor Latch enable */
145#define SC16IS7XX_LCR_WORD_LEN_5 (0x00)
146#define SC16IS7XX_LCR_WORD_LEN_6 (0x01)
147#define SC16IS7XX_LCR_WORD_LEN_7 (0x02)
148#define SC16IS7XX_LCR_WORD_LEN_8 (0x03)
149#define SC16IS7XX_LCR_CONF_MODE_A SC16IS7XX_LCR_DLAB_BIT /* Special
150 * reg set */
151#define SC16IS7XX_LCR_CONF_MODE_B 0xBF /* Enhanced
152 * reg set */
153
154/* MCR register bits */
155#define SC16IS7XX_MCR_DTR_BIT (1 << 0) /* DTR complement
156 * - only on 75x/76x
157 */
158#define SC16IS7XX_MCR_RTS_BIT (1 << 1) /* RTS complement */
159#define SC16IS7XX_MCR_TCRTLR_BIT (1 << 2) /* TCR/TLR register enable */
160#define SC16IS7XX_MCR_LOOP_BIT (1 << 4) /* Enable loopback test mode */
161#define SC16IS7XX_MCR_XONANY_BIT (1 << 5) /* Enable Xon Any
162 * - write enabled
163 * if (EFR[4] == 1)
164 */
165#define SC16IS7XX_MCR_IRDA_BIT (1 << 6) /* Enable IrDA mode
166 * - write enabled
167 * if (EFR[4] == 1)
168 */
169#define SC16IS7XX_MCR_CLKSEL_BIT (1 << 7) /* Divide clock by 4
170 * - write enabled
171 * if (EFR[4] == 1)
172 */
173
174/* LSR register bits */
175#define SC16IS7XX_LSR_DR_BIT (1 << 0) /* Receiver data ready */
176#define SC16IS7XX_LSR_OE_BIT (1 << 1) /* Overrun Error */
177#define SC16IS7XX_LSR_PE_BIT (1 << 2) /* Parity Error */
178#define SC16IS7XX_LSR_FE_BIT (1 << 3) /* Frame Error */
179#define SC16IS7XX_LSR_BI_BIT (1 << 4) /* Break Interrupt */
180#define SC16IS7XX_LSR_BRK_ERROR_MASK 0x1E /* BI, FE, PE, OE bits */
181#define SC16IS7XX_LSR_THRE_BIT (1 << 5) /* TX holding register empty */
182#define SC16IS7XX_LSR_TEMT_BIT (1 << 6) /* Transmitter empty */
183#define SC16IS7XX_LSR_FIFOE_BIT (1 << 7) /* Fifo Error */
184
185/* MSR register bits */
186#define SC16IS7XX_MSR_DCTS_BIT (1 << 0) /* Delta CTS Clear To Send */
187#define SC16IS7XX_MSR_DDSR_BIT (1 << 1) /* Delta DSR Data Set Ready
188 * or (IO4)
189 * - only on 75x/76x
190 */
191#define SC16IS7XX_MSR_DRI_BIT (1 << 2) /* Delta RI Ring Indicator
192 * or (IO7)
193 * - only on 75x/76x
194 */
195#define SC16IS7XX_MSR_DCD_BIT (1 << 3) /* Delta CD Carrier Detect
196 * or (IO6)
197 * - only on 75x/76x
198 */
199#define SC16IS7XX_MSR_CTS_BIT (1 << 4) /* CTS */
200#define SC16IS7XX_MSR_DSR_BIT (1 << 5) /* DSR (IO4)
201 * - only on 75x/76x
202 */
203#define SC16IS7XX_MSR_RI_BIT (1 << 6) /* RI (IO7)
204 * - only on 75x/76x
205 */
206#define SC16IS7XX_MSR_CD_BIT (1 << 7) /* CD (IO6)
207 * - only on 75x/76x
208 */
209#define SC16IS7XX_MSR_DELTA_MASK 0x0F /* Any of the delta bits! */
210
211/*
212 * TCR register bits
213 * TCR trigger levels are available from 0 to 60 characters with a granularity
214 * of four.
215 * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
216 * no built-in hardware check to make sure this condition is met. Also, the TCR
217 * must be programmed with this condition before auto RTS or software flow
218 * control is enabled to avoid spurious operation of the device.
219 */
220#define SC16IS7XX_TCR_RX_HALT(words) ((((words) / 4) & 0x0f) << 0)
221#define SC16IS7XX_TCR_RX_RESUME(words) ((((words) / 4) & 0x0f) << 4)
222
223/*
224 * TLR register bits
225 * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
226 * FIFO Control Register (FCR) are used for the transmit and receive FIFO
227 * trigger levels. Trigger levels from 4 characters to 60 characters are
228 * available with a granularity of four.
229 *
230 * When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the
231 * trigger level setting defined in FCR. If TLR has non-zero trigger level value
232 * the trigger level defined in FCR is discarded. This applies to both transmit
233 * FIFO and receive FIFO trigger level setting.
234 *
235 * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
236 * default state, that is, '00'.
237 */
238#define SC16IS7XX_TLR_TX_TRIGGER(words) ((((words) / 4) & 0x0f) << 0)
239#define SC16IS7XX_TLR_RX_TRIGGER(words) ((((words) / 4) & 0x0f) << 4)
240
241/* IOControl register bits (Only 750/760) */
242#define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */
243#define SC16IS7XX_IOCONTROL_MODEM_BIT (1 << 1) /* Enable GPIO[7:4] as modem pins */
244#define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */
245
246/* EFCR register bits */
247#define SC16IS7XX_EFCR_9BIT_MODE_BIT (1 << 0) /* Enable 9-bit or Multidrop
248 * mode (RS485) */
249#define SC16IS7XX_EFCR_RXDISABLE_BIT (1 << 1) /* Disable receiver */
250#define SC16IS7XX_EFCR_TXDISABLE_BIT (1 << 2) /* Disable transmitter */
251#define SC16IS7XX_EFCR_AUTO_RS485_BIT (1 << 4) /* Auto RS485 RTS direction */
252#define SC16IS7XX_EFCR_RTS_INVERT_BIT (1 << 5) /* RTS output inversion */
253#define SC16IS7XX_EFCR_IRDA_MODE_BIT (1 << 7) /* IrDA mode
254 * 0 = rate upto 115.2 kbit/s
255 * - Only 750/760
256 * 1 = rate upto 1.152 Mbit/s
257 * - Only 760
258 */
259
260/* EFR register bits */
261#define SC16IS7XX_EFR_AUTORTS_BIT (1 << 6) /* Auto RTS flow ctrl enable */
262#define SC16IS7XX_EFR_AUTOCTS_BIT (1 << 7) /* Auto CTS flow ctrl enable */
263#define SC16IS7XX_EFR_XOFF2_DETECT_BIT (1 << 5) /* Enable Xoff2 detection */
264#define SC16IS7XX_EFR_ENABLE_BIT (1 << 4) /* Enable enhanced functions
265 * and writing to IER[7:4],
266 * FCR[5:4], MCR[7:5]
267 */
268#define SC16IS7XX_EFR_SWFLOW3_BIT (1 << 3) /* SWFLOW bit 3 */
269#define SC16IS7XX_EFR_SWFLOW2_BIT (1 << 2) /* SWFLOW bit 2
270 *
271 * SWFLOW bits 3 & 2 table:
272 * 00 -> no transmitter flow
273 * control
274 * 01 -> transmitter generates
275 * XON2 and XOFF2
276 * 10 -> transmitter generates
277 * XON1 and XOFF1
278 * 11 -> transmitter generates
279 * XON1, XON2, XOFF1 and
280 * XOFF2
281 */
282#define SC16IS7XX_EFR_SWFLOW1_BIT (1 << 1) /* SWFLOW bit 2 */
283#define SC16IS7XX_EFR_SWFLOW0_BIT (1 << 0) /* SWFLOW bit 3
284 *
285 * SWFLOW bits 3 & 2 table:
286 * 00 -> no received flow
287 * control
288 * 01 -> receiver compares
289 * XON2 and XOFF2
290 * 10 -> receiver compares
291 * XON1 and XOFF1
292 * 11 -> receiver compares
293 * XON1, XON2, XOFF1 and
294 * XOFF2
295 */
296
297/* Misc definitions */
298#define SC16IS7XX_FIFO_SIZE (64)
299#define SC16IS7XX_REG_SHIFT 2
300
301struct sc16is7xx_devtype {
302 char name[10];
303 int nr_gpio;
304 int nr_uart;
305};
306
307#define SC16IS7XX_RECONF_MD (1 << 0)
308#define SC16IS7XX_RECONF_IER (1 << 1)
309#define SC16IS7XX_RECONF_RS485 (1 << 2)
310
311struct sc16is7xx_one_config {
312 unsigned int flags;
313 u8 ier_clear;
314};
315
316struct sc16is7xx_one {
317 struct uart_port port;
318 u8 line;
319 struct kthread_work tx_work;
320 struct kthread_work reg_work;
321 struct sc16is7xx_one_config config;
322};
323
324struct sc16is7xx_port {
325 const struct sc16is7xx_devtype *devtype;
326 struct regmap *regmap;
327 struct clk *clk;
328#ifdef CONFIG_GPIOLIB
329 struct gpio_chip gpio;
330#endif
331 unsigned char buf[SC16IS7XX_FIFO_SIZE];
332 struct kthread_worker kworker;
333 struct task_struct *kworker_task;
334 struct kthread_work irq_work;
335 struct sc16is7xx_one p[0];
336};
337
338static unsigned long sc16is7xx_lines;
339
340static struct uart_driver sc16is7xx_uart = {
341 .owner = THIS_MODULE,
342 .dev_name = "ttySC",
343 .nr = SC16IS7XX_MAX_DEVS,
344};
345
346#define to_sc16is7xx_port(p,e) ((container_of((p), struct sc16is7xx_port, e)))
347#define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e)))
348
349static int sc16is7xx_line(struct uart_port *port)
350{
351 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
352
353 return one->line;
354}
355
356static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
357{
358 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
359 unsigned int val = 0;
360 const u8 line = sc16is7xx_line(port);
361
362 regmap_read(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line, &val);
363
364 return val;
365}
366
367static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
368{
369 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
370 const u8 line = sc16is7xx_line(port);
371
372 regmap_write(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line, val);
373}
374
375static void sc16is7xx_fifo_read(struct uart_port *port, unsigned int rxlen)
376{
377 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
378 const u8 line = sc16is7xx_line(port);
379 u8 addr = (SC16IS7XX_RHR_REG << SC16IS7XX_REG_SHIFT) | line;
380
381 regcache_cache_bypass(s->regmap, true);
382 regmap_raw_read(s->regmap, addr, s->buf, rxlen);
383 regcache_cache_bypass(s->regmap, false);
384}
385
386static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
387{
388 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
389 const u8 line = sc16is7xx_line(port);
390 u8 addr = (SC16IS7XX_THR_REG << SC16IS7XX_REG_SHIFT) | line;
391
392 /*
393 * Don't send zero-length data, at least on SPI it confuses the chip
394 * delivering wrong TXLVL data.
395 */
396 if (unlikely(!to_send))
397 return;
398
399 regcache_cache_bypass(s->regmap, true);
400 regmap_raw_write(s->regmap, addr, s->buf, to_send);
401 regcache_cache_bypass(s->regmap, false);
402}
403
404static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
405 u8 mask, u8 val)
406{
407 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
408 const u8 line = sc16is7xx_line(port);
409
410 regmap_update_bits(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line,
411 mask, val);
412}
413
414static int sc16is7xx_alloc_line(void)
415{
416 int i;
417
418 BUILD_BUG_ON(SC16IS7XX_MAX_DEVS > BITS_PER_LONG);
419
420 for (i = 0; i < SC16IS7XX_MAX_DEVS; i++)
421 if (!test_and_set_bit(i, &sc16is7xx_lines))
422 break;
423
424 return i;
425}
426
427static void sc16is7xx_power(struct uart_port *port, int on)
428{
429 sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
430 SC16IS7XX_IER_SLEEP_BIT,
431 on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
432}
433
434static const struct sc16is7xx_devtype sc16is74x_devtype = {
435 .name = "SC16IS74X",
436 .nr_gpio = 0,
437 .nr_uart = 1,
438};
439
440static const struct sc16is7xx_devtype sc16is750_devtype = {
441 .name = "SC16IS750",
442 .nr_gpio = 8,
443 .nr_uart = 1,
444};
445
446static const struct sc16is7xx_devtype sc16is752_devtype = {
447 .name = "SC16IS752",
448 .nr_gpio = 8,
449 .nr_uart = 2,
450};
451
452static const struct sc16is7xx_devtype sc16is760_devtype = {
453 .name = "SC16IS760",
454 .nr_gpio = 8,
455 .nr_uart = 1,
456};
457
458static const struct sc16is7xx_devtype sc16is762_devtype = {
459 .name = "SC16IS762",
460 .nr_gpio = 8,
461 .nr_uart = 2,
462};
463
464static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
465{
466 switch (reg >> SC16IS7XX_REG_SHIFT) {
467 case SC16IS7XX_RHR_REG:
468 case SC16IS7XX_IIR_REG:
469 case SC16IS7XX_LSR_REG:
470 case SC16IS7XX_MSR_REG:
471 case SC16IS7XX_TXLVL_REG:
472 case SC16IS7XX_RXLVL_REG:
473 case SC16IS7XX_IOSTATE_REG:
474 return true;
475 default:
476 break;
477 }
478
479 return false;
480}
481
482static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
483{
484 switch (reg >> SC16IS7XX_REG_SHIFT) {
485 case SC16IS7XX_RHR_REG:
486 return true;
487 default:
488 break;
489 }
490
491 return false;
492}
493
494static int sc16is7xx_set_baud(struct uart_port *port, int baud)
495{
496 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
497 u8 lcr;
498 u8 prescaler = 0;
499 unsigned long clk = port->uartclk, div = clk / 16 / baud;
500
501 if (div > 0xffff) {
502 prescaler = SC16IS7XX_MCR_CLKSEL_BIT;
503 div /= 4;
504 }
505
506 lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
507
508 /* Open the LCR divisors for configuration */
509 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
510 SC16IS7XX_LCR_CONF_MODE_B);
511
512 /* Enable enhanced features */
513 regcache_cache_bypass(s->regmap, true);
514 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG,
515 SC16IS7XX_EFR_ENABLE_BIT);
516 regcache_cache_bypass(s->regmap, false);
517
518 /* Put LCR back to the normal mode */
519 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
520
521 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
522 SC16IS7XX_MCR_CLKSEL_BIT,
523 prescaler);
524
525 /* Open the LCR divisors for configuration */
526 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
527 SC16IS7XX_LCR_CONF_MODE_A);
528
529 /* Write the new divisor */
530 regcache_cache_bypass(s->regmap, true);
531 sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
532 sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
533 regcache_cache_bypass(s->regmap, false);
534
535 /* Put LCR back to the normal mode */
536 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
537
538 return DIV_ROUND_CLOSEST(clk / 16, div);
539}
540
541static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
542 unsigned int iir)
543{
544 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
545 unsigned int lsr = 0, ch, flag, bytes_read, i;
546 bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
547
548 if (unlikely(rxlen >= sizeof(s->buf))) {
549 dev_warn_ratelimited(port->dev,
550 "ttySC%i: Possible RX FIFO overrun: %d\n",
551 port->line, rxlen);
552 port->icount.buf_overrun++;
553 /* Ensure sanity of RX level */
554 rxlen = sizeof(s->buf);
555 }
556
557 while (rxlen) {
558 /* Only read lsr if there are possible errors in FIFO */
559 if (read_lsr) {
560 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
561 if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
562 read_lsr = false; /* No errors left in FIFO */
563 } else
564 lsr = 0;
565
566 if (read_lsr) {
567 s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
568 bytes_read = 1;
569 } else {
570 sc16is7xx_fifo_read(port, rxlen);
571 bytes_read = rxlen;
572 }
573
574 lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
575
576 port->icount.rx++;
577 flag = TTY_NORMAL;
578
579 if (unlikely(lsr)) {
580 if (lsr & SC16IS7XX_LSR_BI_BIT) {
581 port->icount.brk++;
582 if (uart_handle_break(port))
583 continue;
584 } else if (lsr & SC16IS7XX_LSR_PE_BIT)
585 port->icount.parity++;
586 else if (lsr & SC16IS7XX_LSR_FE_BIT)
587 port->icount.frame++;
588 else if (lsr & SC16IS7XX_LSR_OE_BIT)
589 port->icount.overrun++;
590
591 lsr &= port->read_status_mask;
592 if (lsr & SC16IS7XX_LSR_BI_BIT)
593 flag = TTY_BREAK;
594 else if (lsr & SC16IS7XX_LSR_PE_BIT)
595 flag = TTY_PARITY;
596 else if (lsr & SC16IS7XX_LSR_FE_BIT)
597 flag = TTY_FRAME;
598 else if (lsr & SC16IS7XX_LSR_OE_BIT)
599 flag = TTY_OVERRUN;
600 }
601
602 for (i = 0; i < bytes_read; ++i) {
603 ch = s->buf[i];
604 if (uart_handle_sysrq_char(port, ch))
605 continue;
606
607 if (lsr & port->ignore_status_mask)
608 continue;
609
610 uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
611 flag);
612 }
613 rxlen -= bytes_read;
614 }
615
616 tty_flip_buffer_push(&port->state->port);
617}
618
619static void sc16is7xx_handle_tx(struct uart_port *port)
620{
621 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
622 struct circ_buf *xmit = &port->state->xmit;
623 unsigned int txlen, to_send, i;
624
625 if (unlikely(port->x_char)) {
626 sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
627 port->icount.tx++;
628 port->x_char = 0;
629 return;
630 }
631
632 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
633 return;
634
635 /* Get length of data pending in circular buffer */
636 to_send = uart_circ_chars_pending(xmit);
637 if (likely(to_send)) {
638 /* Limit to size of TX FIFO */
639 txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
640 if (txlen > SC16IS7XX_FIFO_SIZE) {
641 dev_err_ratelimited(port->dev,
642 "chip reports %d free bytes in TX fifo, but it only has %d",
643 txlen, SC16IS7XX_FIFO_SIZE);
644 txlen = 0;
645 }
646 to_send = (to_send > txlen) ? txlen : to_send;
647
648 /* Add data to send */
649 port->icount.tx += to_send;
650
651 /* Convert to linear buffer */
652 for (i = 0; i < to_send; ++i) {
653 s->buf[i] = xmit->buf[xmit->tail];
654 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
655 }
656
657 sc16is7xx_fifo_write(port, to_send);
658 }
659
660 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
661 uart_write_wakeup(port);
662}
663
664static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
665{
666 struct uart_port *port = &s->p[portno].port;
667
668 do {
669 unsigned int iir, msr, rxlen;
670
671 iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
672 if (iir & SC16IS7XX_IIR_NO_INT_BIT)
673 break;
674
675 iir &= SC16IS7XX_IIR_ID_MASK;
676
677 switch (iir) {
678 case SC16IS7XX_IIR_RDI_SRC:
679 case SC16IS7XX_IIR_RLSE_SRC:
680 case SC16IS7XX_IIR_RTOI_SRC:
681 case SC16IS7XX_IIR_XOFFI_SRC:
682 rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
683 if (rxlen)
684 sc16is7xx_handle_rx(port, rxlen, iir);
685 break;
686
687 case SC16IS7XX_IIR_CTSRTS_SRC:
688 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
689 uart_handle_cts_change(port,
690 !!(msr & SC16IS7XX_MSR_DCTS_BIT));
691 break;
692 case SC16IS7XX_IIR_THRI_SRC:
693 sc16is7xx_handle_tx(port);
694 break;
695 default:
696 dev_err_ratelimited(port->dev,
697 "ttySC%i: Unexpected interrupt: %x",
698 port->line, iir);
699 break;
700 }
701 } while (1);
702}
703
704static void sc16is7xx_ist(struct kthread_work *ws)
705{
706 struct sc16is7xx_port *s = to_sc16is7xx_port(ws, irq_work);
707 int i;
708
709 for (i = 0; i < s->devtype->nr_uart; ++i)
710 sc16is7xx_port_irq(s, i);
711}
712
713static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
714{
715 struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
716
717 queue_kthread_work(&s->kworker, &s->irq_work);
718
719 return IRQ_HANDLED;
720}
721
722static void sc16is7xx_tx_proc(struct kthread_work *ws)
723{
724 struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
725
726 if ((port->rs485.flags & SER_RS485_ENABLED) &&
727 (port->rs485.delay_rts_before_send > 0))
728 msleep(port->rs485.delay_rts_before_send);
729
730 sc16is7xx_handle_tx(port);
731}
732
733static void sc16is7xx_reconf_rs485(struct uart_port *port)
734{
735 const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
736 SC16IS7XX_EFCR_RTS_INVERT_BIT;
737 u32 efcr = 0;
738 struct serial_rs485 *rs485 = &port->rs485;
739 unsigned long irqflags;
740
741 spin_lock_irqsave(&port->lock, irqflags);
742 if (rs485->flags & SER_RS485_ENABLED) {
743 efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT;
744
745 if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
746 efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
747 }
748 spin_unlock_irqrestore(&port->lock, irqflags);
749
750 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
751}
752
753static void sc16is7xx_reg_proc(struct kthread_work *ws)
754{
755 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
756 struct sc16is7xx_one_config config;
757 unsigned long irqflags;
758
759 spin_lock_irqsave(&one->port.lock, irqflags);
760 config = one->config;
761 memset(&one->config, 0, sizeof(one->config));
762 spin_unlock_irqrestore(&one->port.lock, irqflags);
763
764 if (config.flags & SC16IS7XX_RECONF_MD) {
765 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
766 SC16IS7XX_MCR_LOOP_BIT,
767 (one->port.mctrl & TIOCM_LOOP) ?
768 SC16IS7XX_MCR_LOOP_BIT : 0);
769 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
770 SC16IS7XX_MCR_RTS_BIT,
771 (one->port.mctrl & TIOCM_RTS) ?
772 SC16IS7XX_MCR_RTS_BIT : 0);
773 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
774 SC16IS7XX_MCR_DTR_BIT,
775 (one->port.mctrl & TIOCM_DTR) ?
776 SC16IS7XX_MCR_DTR_BIT : 0);
777 }
778 if (config.flags & SC16IS7XX_RECONF_IER)
779 sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
780 config.ier_clear, 0);
781
782 if (config.flags & SC16IS7XX_RECONF_RS485)
783 sc16is7xx_reconf_rs485(&one->port);
784}
785
786static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
787{
788 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
789 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
790
791 one->config.flags |= SC16IS7XX_RECONF_IER;
792 one->config.ier_clear |= bit;
793 queue_kthread_work(&s->kworker, &one->reg_work);
794}
795
796static void sc16is7xx_stop_tx(struct uart_port *port)
797{
798 sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
799}
800
801static void sc16is7xx_stop_rx(struct uart_port *port)
802{
803 sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
804}
805
806static void sc16is7xx_start_tx(struct uart_port *port)
807{
808 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
809 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
810
811 queue_kthread_work(&s->kworker, &one->tx_work);
812}
813
814static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
815{
816 unsigned int lsr;
817
818 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
819
820 return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
821}
822
823static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
824{
825 /* DCD and DSR are not wired and CTS/RTS is handled automatically
826 * so just indicate DSR and CAR asserted
827 */
828 return TIOCM_DSR | TIOCM_CAR;
829}
830
831static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
832{
833 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
834 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
835
836 one->config.flags |= SC16IS7XX_RECONF_MD;
837 queue_kthread_work(&s->kworker, &one->reg_work);
838}
839
840static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
841{
842 sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
843 SC16IS7XX_LCR_TXBREAK_BIT,
844 break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
845}
846
847static void sc16is7xx_set_termios(struct uart_port *port,
848 struct ktermios *termios,
849 struct ktermios *old)
850{
851 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
852 unsigned int lcr, flow = 0;
853 int baud;
854
855 /* Mask termios capabilities we don't support */
856 termios->c_cflag &= ~CMSPAR;
857
858 /* Word size */
859 switch (termios->c_cflag & CSIZE) {
860 case CS5:
861 lcr = SC16IS7XX_LCR_WORD_LEN_5;
862 break;
863 case CS6:
864 lcr = SC16IS7XX_LCR_WORD_LEN_6;
865 break;
866 case CS7:
867 lcr = SC16IS7XX_LCR_WORD_LEN_7;
868 break;
869 case CS8:
870 lcr = SC16IS7XX_LCR_WORD_LEN_8;
871 break;
872 default:
873 lcr = SC16IS7XX_LCR_WORD_LEN_8;
874 termios->c_cflag &= ~CSIZE;
875 termios->c_cflag |= CS8;
876 break;
877 }
878
879 /* Parity */
880 if (termios->c_cflag & PARENB) {
881 lcr |= SC16IS7XX_LCR_PARITY_BIT;
882 if (!(termios->c_cflag & PARODD))
883 lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
884 }
885
886 /* Stop bits */
887 if (termios->c_cflag & CSTOPB)
888 lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
889
890 /* Set read status mask */
891 port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
892 if (termios->c_iflag & INPCK)
893 port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
894 SC16IS7XX_LSR_FE_BIT;
895 if (termios->c_iflag & (BRKINT | PARMRK))
896 port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
897
898 /* Set status ignore mask */
899 port->ignore_status_mask = 0;
900 if (termios->c_iflag & IGNBRK)
901 port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
902 if (!(termios->c_cflag & CREAD))
903 port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
904
905 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
906 SC16IS7XX_LCR_CONF_MODE_B);
907
908 /* Configure flow control */
909 regcache_cache_bypass(s->regmap, true);
910 sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
911 sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
912 if (termios->c_cflag & CRTSCTS)
913 flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
914 SC16IS7XX_EFR_AUTORTS_BIT;
915 if (termios->c_iflag & IXON)
916 flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
917 if (termios->c_iflag & IXOFF)
918 flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
919
920 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, flow);
921 regcache_cache_bypass(s->regmap, false);
922
923 /* Update LCR register */
924 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
925
926 /* Get baud rate generator configuration */
927 baud = uart_get_baud_rate(port, termios, old,
928 port->uartclk / 16 / 4 / 0xffff,
929 port->uartclk / 16);
930
931 /* Setup baudrate generator */
932 baud = sc16is7xx_set_baud(port, baud);
933
934 /* Update timeout according to new baud rate */
935 uart_update_timeout(port, termios->c_cflag, baud);
936}
937
938static int sc16is7xx_config_rs485(struct uart_port *port,
939 struct serial_rs485 *rs485)
940{
941 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
942 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
943
944 if (rs485->flags & SER_RS485_ENABLED) {
945 bool rts_during_rx, rts_during_tx;
946
947 rts_during_rx = rs485->flags & SER_RS485_RTS_AFTER_SEND;
948 rts_during_tx = rs485->flags & SER_RS485_RTS_ON_SEND;
949
950 if (rts_during_rx == rts_during_tx)
951 dev_err(port->dev,
952 "unsupported RTS signalling on_send:%d after_send:%d - exactly one of RS485 RTS flags should be set\n",
953 rts_during_tx, rts_during_rx);
954
955 /*
956 * RTS signal is handled by HW, it's timing can't be influenced.
957 * However, it's sometimes useful to delay TX even without RTS
958 * control therefore we try to handle .delay_rts_before_send.
959 */
960 if (rs485->delay_rts_after_send)
961 return -EINVAL;
962 }
963
964 port->rs485 = *rs485;
965 one->config.flags |= SC16IS7XX_RECONF_RS485;
966 queue_kthread_work(&s->kworker, &one->reg_work);
967
968 return 0;
969}
970
971static int sc16is7xx_startup(struct uart_port *port)
972{
973 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
974 unsigned int val;
975
976 sc16is7xx_power(port, 1);
977
978 /* Reset FIFOs*/
979 val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
980 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
981 udelay(5);
982 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
983 SC16IS7XX_FCR_FIFO_BIT);
984
985 /* Enable EFR */
986 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
987 SC16IS7XX_LCR_CONF_MODE_B);
988
989 regcache_cache_bypass(s->regmap, true);
990
991 /* Enable write access to enhanced features and internal clock div */
992 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG,
993 SC16IS7XX_EFR_ENABLE_BIT);
994
995 /* Enable TCR/TLR */
996 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
997 SC16IS7XX_MCR_TCRTLR_BIT,
998 SC16IS7XX_MCR_TCRTLR_BIT);
999
1000 /* Configure flow control levels */
1001 /* Flow control halt level 48, resume level 24 */
1002 sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
1003 SC16IS7XX_TCR_RX_RESUME(24) |
1004 SC16IS7XX_TCR_RX_HALT(48));
1005
1006 regcache_cache_bypass(s->regmap, false);
1007
1008 /* Now, initialize the UART */
1009 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
1010
1011 /* Enable the Rx and Tx FIFO */
1012 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1013 SC16IS7XX_EFCR_RXDISABLE_BIT |
1014 SC16IS7XX_EFCR_TXDISABLE_BIT,
1015 0);
1016
1017 /* Enable RX, TX, CTS change interrupts */
1018 val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_THRI_BIT |
1019 SC16IS7XX_IER_CTSI_BIT;
1020 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1021
1022 return 0;
1023}
1024
1025static void sc16is7xx_shutdown(struct uart_port *port)
1026{
1027 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1028
1029 /* Disable all interrupts */
1030 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1031 /* Disable TX/RX */
1032 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1033 SC16IS7XX_EFCR_RXDISABLE_BIT |
1034 SC16IS7XX_EFCR_TXDISABLE_BIT,
1035 SC16IS7XX_EFCR_RXDISABLE_BIT |
1036 SC16IS7XX_EFCR_TXDISABLE_BIT);
1037
1038 sc16is7xx_power(port, 0);
1039
1040 flush_kthread_worker(&s->kworker);
1041}
1042
1043static const char *sc16is7xx_type(struct uart_port *port)
1044{
1045 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1046
1047 return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1048}
1049
1050static int sc16is7xx_request_port(struct uart_port *port)
1051{
1052 /* Do nothing */
1053 return 0;
1054}
1055
1056static void sc16is7xx_config_port(struct uart_port *port, int flags)
1057{
1058 if (flags & UART_CONFIG_TYPE)
1059 port->type = PORT_SC16IS7XX;
1060}
1061
1062static int sc16is7xx_verify_port(struct uart_port *port,
1063 struct serial_struct *s)
1064{
1065 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1066 return -EINVAL;
1067 if (s->irq != port->irq)
1068 return -EINVAL;
1069
1070 return 0;
1071}
1072
1073static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1074 unsigned int oldstate)
1075{
1076 sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1077}
1078
1079static void sc16is7xx_null_void(struct uart_port *port)
1080{
1081 /* Do nothing */
1082}
1083
1084static const struct uart_ops sc16is7xx_ops = {
1085 .tx_empty = sc16is7xx_tx_empty,
1086 .set_mctrl = sc16is7xx_set_mctrl,
1087 .get_mctrl = sc16is7xx_get_mctrl,
1088 .stop_tx = sc16is7xx_stop_tx,
1089 .start_tx = sc16is7xx_start_tx,
1090 .stop_rx = sc16is7xx_stop_rx,
1091 .break_ctl = sc16is7xx_break_ctl,
1092 .startup = sc16is7xx_startup,
1093 .shutdown = sc16is7xx_shutdown,
1094 .set_termios = sc16is7xx_set_termios,
1095 .type = sc16is7xx_type,
1096 .request_port = sc16is7xx_request_port,
1097 .release_port = sc16is7xx_null_void,
1098 .config_port = sc16is7xx_config_port,
1099 .verify_port = sc16is7xx_verify_port,
1100 .pm = sc16is7xx_pm,
1101};
1102
1103#ifdef CONFIG_GPIOLIB
1104static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1105{
1106 unsigned int val;
1107 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1108 gpio);
1109 struct uart_port *port = &s->p[0].port;
1110
1111 val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1112
1113 return !!(val & BIT(offset));
1114}
1115
1116static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1117{
1118 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1119 gpio);
1120 struct uart_port *port = &s->p[0].port;
1121
1122 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1123 val ? BIT(offset) : 0);
1124}
1125
1126static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1127 unsigned offset)
1128{
1129 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1130 gpio);
1131 struct uart_port *port = &s->p[0].port;
1132
1133 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1134
1135 return 0;
1136}
1137
1138static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1139 unsigned offset, int val)
1140{
1141 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1142 gpio);
1143 struct uart_port *port = &s->p[0].port;
1144
1145 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1146 val ? BIT(offset) : 0);
1147 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1148 BIT(offset));
1149
1150 return 0;
1151}
1152#endif
1153
1154static int sc16is7xx_probe(struct device *dev,
1155 const struct sc16is7xx_devtype *devtype,
1156 struct regmap *regmap, int irq, unsigned long flags)
1157{
1158 struct sched_param sched_param = { .sched_priority = MAX_RT_PRIO / 2 };
1159 unsigned long freq, *pfreq = dev_get_platdata(dev);
1160 int i, ret;
1161 struct sc16is7xx_port *s;
1162
1163 if (IS_ERR(regmap))
1164 return PTR_ERR(regmap);
1165
1166 /* Alloc port structure */
1167 s = devm_kzalloc(dev, sizeof(*s) +
1168 sizeof(struct sc16is7xx_one) * devtype->nr_uart,
1169 GFP_KERNEL);
1170 if (!s) {
1171 dev_err(dev, "Error allocating port structure\n");
1172 return -ENOMEM;
1173 }
1174
1175 s->clk = devm_clk_get(dev, NULL);
1176 if (IS_ERR(s->clk)) {
1177 if (pfreq)
1178 freq = *pfreq;
1179 else
1180 return PTR_ERR(s->clk);
1181 } else {
1182 clk_prepare_enable(s->clk);
1183 freq = clk_get_rate(s->clk);
1184 }
1185
1186 s->regmap = regmap;
1187 s->devtype = devtype;
1188 dev_set_drvdata(dev, s);
1189
1190 init_kthread_worker(&s->kworker);
1191 init_kthread_work(&s->irq_work, sc16is7xx_ist);
1192 s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1193 "sc16is7xx");
1194 if (IS_ERR(s->kworker_task)) {
1195 ret = PTR_ERR(s->kworker_task);
1196 goto out_clk;
1197 }
1198 sched_setscheduler(s->kworker_task, SCHED_FIFO, &sched_param);
1199
1200#ifdef CONFIG_GPIOLIB
1201 if (devtype->nr_gpio) {
1202 /* Setup GPIO cotroller */
1203 s->gpio.owner = THIS_MODULE;
1204 s->gpio.parent = dev;
1205 s->gpio.label = dev_name(dev);
1206 s->gpio.direction_input = sc16is7xx_gpio_direction_input;
1207 s->gpio.get = sc16is7xx_gpio_get;
1208 s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1209 s->gpio.set = sc16is7xx_gpio_set;
1210 s->gpio.base = -1;
1211 s->gpio.ngpio = devtype->nr_gpio;
1212 s->gpio.can_sleep = 1;
1213 ret = gpiochip_add(&s->gpio);
1214 if (ret)
1215 goto out_thread;
1216 }
1217#endif
1218
1219 for (i = 0; i < devtype->nr_uart; ++i) {
1220 s->p[i].line = i;
1221 /* Initialize port data */
1222 s->p[i].port.dev = dev;
1223 s->p[i].port.irq = irq;
1224 s->p[i].port.type = PORT_SC16IS7XX;
1225 s->p[i].port.fifosize = SC16IS7XX_FIFO_SIZE;
1226 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1227 s->p[i].port.iotype = UPIO_PORT;
1228 s->p[i].port.uartclk = freq;
1229 s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1230 s->p[i].port.ops = &sc16is7xx_ops;
1231 s->p[i].port.line = sc16is7xx_alloc_line();
1232 if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
1233 ret = -ENOMEM;
1234 goto out_ports;
1235 }
1236
1237 /* Disable all interrupts */
1238 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1239 /* Disable TX/RX */
1240 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1241 SC16IS7XX_EFCR_RXDISABLE_BIT |
1242 SC16IS7XX_EFCR_TXDISABLE_BIT);
1243 /* Initialize kthread work structs */
1244 init_kthread_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1245 init_kthread_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1246 /* Register port */
1247 uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1248 /* Go to suspend mode */
1249 sc16is7xx_power(&s->p[i].port, 0);
1250 }
1251
1252 /* Setup interrupt */
1253 ret = devm_request_irq(dev, irq, sc16is7xx_irq,
1254 IRQF_ONESHOT | flags, dev_name(dev), s);
1255 if (!ret)
1256 return 0;
1257
1258out_ports:
1259 for (i--; i >= 0; i--) {
1260 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1261 clear_bit(s->p[i].port.line, &sc16is7xx_lines);
1262 }
1263
1264#ifdef CONFIG_GPIOLIB
1265 if (devtype->nr_gpio)
1266 gpiochip_remove(&s->gpio);
1267
1268out_thread:
1269#endif
1270 kthread_stop(s->kworker_task);
1271
1272out_clk:
1273 if (!IS_ERR(s->clk))
1274 clk_disable_unprepare(s->clk);
1275
1276 return ret;
1277}
1278
1279static int sc16is7xx_remove(struct device *dev)
1280{
1281 struct sc16is7xx_port *s = dev_get_drvdata(dev);
1282 int i;
1283
1284#ifdef CONFIG_GPIOLIB
1285 if (s->devtype->nr_gpio)
1286 gpiochip_remove(&s->gpio);
1287#endif
1288
1289 for (i = 0; i < s->devtype->nr_uart; i++) {
1290 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1291 clear_bit(s->p[i].port.line, &sc16is7xx_lines);
1292 sc16is7xx_power(&s->p[i].port, 0);
1293 }
1294
1295 flush_kthread_worker(&s->kworker);
1296 kthread_stop(s->kworker_task);
1297
1298 if (!IS_ERR(s->clk))
1299 clk_disable_unprepare(s->clk);
1300
1301 return 0;
1302}
1303
1304static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1305 { .compatible = "nxp,sc16is740", .data = &sc16is74x_devtype, },
1306 { .compatible = "nxp,sc16is741", .data = &sc16is74x_devtype, },
1307 { .compatible = "nxp,sc16is750", .data = &sc16is750_devtype, },
1308 { .compatible = "nxp,sc16is752", .data = &sc16is752_devtype, },
1309 { .compatible = "nxp,sc16is760", .data = &sc16is760_devtype, },
1310 { .compatible = "nxp,sc16is762", .data = &sc16is762_devtype, },
1311 { }
1312};
1313MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1314
1315static struct regmap_config regcfg = {
1316 .reg_bits = 7,
1317 .pad_bits = 1,
1318 .val_bits = 8,
1319 .cache_type = REGCACHE_RBTREE,
1320 .volatile_reg = sc16is7xx_regmap_volatile,
1321 .precious_reg = sc16is7xx_regmap_precious,
1322};
1323
1324#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1325static int sc16is7xx_spi_probe(struct spi_device *spi)
1326{
1327 const struct sc16is7xx_devtype *devtype;
1328 unsigned long flags = 0;
1329 struct regmap *regmap;
1330 int ret;
1331
1332 /* Setup SPI bus */
1333 spi->bits_per_word = 8;
1334 /* only supports mode 0 on SC16IS762 */
1335 spi->mode = spi->mode ? : SPI_MODE_0;
1336 spi->max_speed_hz = spi->max_speed_hz ? : 15000000;
1337 ret = spi_setup(spi);
1338 if (ret)
1339 return ret;
1340
1341 if (spi->dev.of_node) {
1342 const struct of_device_id *of_id =
1343 of_match_device(sc16is7xx_dt_ids, &spi->dev);
1344
1345 if (!of_id)
1346 return -ENODEV;
1347
1348 devtype = (struct sc16is7xx_devtype *)of_id->data;
1349 } else {
1350 const struct spi_device_id *id_entry = spi_get_device_id(spi);
1351
1352 devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
1353 flags = IRQF_TRIGGER_FALLING;
1354 }
1355
1356 regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1357 (devtype->nr_uart - 1);
1358 regmap = devm_regmap_init_spi(spi, ®cfg);
1359
1360 return sc16is7xx_probe(&spi->dev, devtype, regmap, spi->irq, flags);
1361}
1362
1363static int sc16is7xx_spi_remove(struct spi_device *spi)
1364{
1365 return sc16is7xx_remove(&spi->dev);
1366}
1367
1368static const struct spi_device_id sc16is7xx_spi_id_table[] = {
1369 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1370 { "sc16is740", (kernel_ulong_t)&sc16is74x_devtype, },
1371 { "sc16is741", (kernel_ulong_t)&sc16is74x_devtype, },
1372 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1373 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1374 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1375 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1376 { }
1377};
1378
1379MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
1380
1381static struct spi_driver sc16is7xx_spi_uart_driver = {
1382 .driver = {
1383 .name = SC16IS7XX_NAME,
1384 .of_match_table = of_match_ptr(sc16is7xx_dt_ids),
1385 },
1386 .probe = sc16is7xx_spi_probe,
1387 .remove = sc16is7xx_spi_remove,
1388 .id_table = sc16is7xx_spi_id_table,
1389};
1390
1391MODULE_ALIAS("spi:sc16is7xx");
1392#endif
1393
1394#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1395static int sc16is7xx_i2c_probe(struct i2c_client *i2c,
1396 const struct i2c_device_id *id)
1397{
1398 const struct sc16is7xx_devtype *devtype;
1399 unsigned long flags = 0;
1400 struct regmap *regmap;
1401
1402 if (i2c->dev.of_node) {
1403 const struct of_device_id *of_id =
1404 of_match_device(sc16is7xx_dt_ids, &i2c->dev);
1405
1406 if (!of_id)
1407 return -ENODEV;
1408
1409 devtype = (struct sc16is7xx_devtype *)of_id->data;
1410 } else {
1411 devtype = (struct sc16is7xx_devtype *)id->driver_data;
1412 flags = IRQF_TRIGGER_FALLING;
1413 }
1414
1415 regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1416 (devtype->nr_uart - 1);
1417 regmap = devm_regmap_init_i2c(i2c, ®cfg);
1418
1419 return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq, flags);
1420}
1421
1422static int sc16is7xx_i2c_remove(struct i2c_client *client)
1423{
1424 return sc16is7xx_remove(&client->dev);
1425}
1426
1427static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
1428 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1429 { "sc16is740", (kernel_ulong_t)&sc16is74x_devtype, },
1430 { "sc16is741", (kernel_ulong_t)&sc16is74x_devtype, },
1431 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1432 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1433 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1434 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1435 { }
1436};
1437MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
1438
1439static struct i2c_driver sc16is7xx_i2c_uart_driver = {
1440 .driver = {
1441 .name = SC16IS7XX_NAME,
1442 .of_match_table = of_match_ptr(sc16is7xx_dt_ids),
1443 },
1444 .probe = sc16is7xx_i2c_probe,
1445 .remove = sc16is7xx_i2c_remove,
1446 .id_table = sc16is7xx_i2c_id_table,
1447};
1448
1449#endif
1450
1451static int __init sc16is7xx_init(void)
1452{
1453 int ret;
1454
1455 ret = uart_register_driver(&sc16is7xx_uart);
1456 if (ret) {
1457 pr_err("Registering UART driver failed\n");
1458 return ret;
1459 }
1460
1461#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1462 ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
1463 if (ret < 0) {
1464 pr_err("failed to init sc16is7xx i2c --> %d\n", ret);
1465 return ret;
1466 }
1467#endif
1468
1469#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1470 ret = spi_register_driver(&sc16is7xx_spi_uart_driver);
1471 if (ret < 0) {
1472 pr_err("failed to init sc16is7xx spi --> %d\n", ret);
1473 return ret;
1474 }
1475#endif
1476 return ret;
1477}
1478module_init(sc16is7xx_init);
1479
1480static void __exit sc16is7xx_exit(void)
1481{
1482#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1483 i2c_del_driver(&sc16is7xx_i2c_uart_driver);
1484#endif
1485
1486#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1487 spi_unregister_driver(&sc16is7xx_spi_uart_driver);
1488#endif
1489 uart_unregister_driver(&sc16is7xx_uart);
1490}
1491module_exit(sc16is7xx_exit);
1492
1493MODULE_LICENSE("GPL");
1494MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1495MODULE_DESCRIPTION("SC16IS7XX serial driver");