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
321 struct sc16is7xx_one_config {
322 unsigned int flags;
323 u8 ier_mask;
324 u8 ier_val;
325 };
326
327 struct 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
341 struct 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
354 static DEFINE_IDA(sc16is7xx_lines);
355
356 static 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
sc16is7xx_port_read(struct uart_port * port,u8 reg)365 static 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
sc16is7xx_port_write(struct uart_port * port,u8 reg,u8 val)375 static 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
sc16is7xx_fifo_read(struct uart_port * port,u8 * rxbuf,unsigned int rxlen)382 static 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
sc16is7xx_fifo_write(struct uart_port * port,u8 * txbuf,u8 to_send)389 static 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
sc16is7xx_port_update(struct uart_port * port,u8 reg,u8 mask,u8 val)403 static 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
sc16is7xx_power(struct uart_port * port,int on)411 static 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 */
sc16is7xx_efr_lock(struct uart_port * port)432 static 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
sc16is7xx_efr_unlock(struct uart_port * port)448 static 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
sc16is7xx_ier_clear(struct uart_port * port,u8 bit)461 static 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
sc16is7xx_ier_set(struct uart_port * port,u8 bit)474 static 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
sc16is7xx_stop_tx(struct uart_port * port)487 static void sc16is7xx_stop_tx(struct uart_port *port)
488 {
489 sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
490 }
491
sc16is7xx_stop_rx(struct uart_port * port)492 static void sc16is7xx_stop_rx(struct uart_port *port)
493 {
494 sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
495 }
496
497 const struct sc16is7xx_devtype sc16is74x_devtype = {
498 .name = "SC16IS74X",
499 .nr_gpio = 0,
500 .nr_uart = 1,
501 };
502 EXPORT_SYMBOL_GPL(sc16is74x_devtype);
503
504 const struct sc16is7xx_devtype sc16is750_devtype = {
505 .name = "SC16IS750",
506 .nr_gpio = 8,
507 .nr_uart = 1,
508 };
509 EXPORT_SYMBOL_GPL(sc16is750_devtype);
510
511 const struct sc16is7xx_devtype sc16is752_devtype = {
512 .name = "SC16IS752",
513 .nr_gpio = 8,
514 .nr_uart = 2,
515 };
516 EXPORT_SYMBOL_GPL(sc16is752_devtype);
517
518 const struct sc16is7xx_devtype sc16is760_devtype = {
519 .name = "SC16IS760",
520 .nr_gpio = 8,
521 .nr_uart = 1,
522 };
523 EXPORT_SYMBOL_GPL(sc16is760_devtype);
524
525 const struct sc16is7xx_devtype sc16is762_devtype = {
526 .name = "SC16IS762",
527 .nr_gpio = 8,
528 .nr_uart = 2,
529 };
530 EXPORT_SYMBOL_GPL(sc16is762_devtype);
531
sc16is7xx_regmap_volatile(struct device * dev,unsigned int reg)532 static 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
sc16is7xx_regmap_precious(struct device * dev,unsigned int reg)549 static 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
sc16is7xx_regmap_noinc(struct device * dev,unsigned int reg)559 static 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 */
sc16is7xx_set_baud(struct uart_port * port,int baud)576 static 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
sc16is7xx_handle_rx(struct uart_port * port,unsigned int rxlen,unsigned int iir)621 static 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
sc16is7xx_handle_tx(struct uart_port * port)700 static 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
sc16is7xx_get_hwmctrl(struct uart_port * port)745 static 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
sc16is7xx_update_mlines(struct sc16is7xx_one * one)757 static 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
sc16is7xx_port_irq(struct sc16is7xx_port * s,int portno)787 static 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
840 out_port_irq:
841 mutex_unlock(&one->efr_lock);
842
843 return rc;
844 }
845
sc16is7xx_irq(int irq,void * dev_id)846 static 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
sc16is7xx_tx_proc(struct kthread_work * ws)864 static 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
sc16is7xx_reconf_rs485(struct uart_port * port)878 static 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
sc16is7xx_reg_proc(struct kthread_work * ws)898 static 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
sc16is7xx_ms_proc(struct kthread_work * ws)936 static 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
sc16is7xx_enable_ms(struct uart_port * port)950 static 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
sc16is7xx_start_tx(struct uart_port * port)960 static 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
sc16is7xx_throttle(struct uart_port * port)968 static 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
sc16is7xx_unthrottle(struct uart_port * port)982 static 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
sc16is7xx_tx_empty(struct uart_port * port)991 static 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
sc16is7xx_get_mctrl(struct uart_port * port)1000 static 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
sc16is7xx_set_mctrl(struct uart_port * port,unsigned int mctrl)1008 static 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
sc16is7xx_break_ctl(struct uart_port * port,int break_state)1017 static 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
sc16is7xx_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)1024 static 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
sc16is7xx_config_rs485(struct uart_port * port,struct ktermios * termios,struct serial_rs485 * rs485)1127 static 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
sc16is7xx_startup(struct uart_port * port)1149 static 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
sc16is7xx_shutdown(struct uart_port * port)1217 static 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
sc16is7xx_type(struct uart_port * port)1238 static 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
sc16is7xx_request_port(struct uart_port * port)1245 static int sc16is7xx_request_port(struct uart_port *port)
1246 {
1247 /* Do nothing */
1248 return 0;
1249 }
1250
sc16is7xx_config_port(struct uart_port * port,int flags)1251 static void sc16is7xx_config_port(struct uart_port *port, int flags)
1252 {
1253 if (flags & UART_CONFIG_TYPE)
1254 port->type = PORT_SC16IS7XX;
1255 }
1256
sc16is7xx_verify_port(struct uart_port * port,struct serial_struct * s)1257 static 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
sc16is7xx_pm(struct uart_port * port,unsigned int state,unsigned int oldstate)1268 static 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
sc16is7xx_null_void(struct uart_port * port)1274 static void sc16is7xx_null_void(struct uart_port *port)
1275 {
1276 /* Do nothing */
1277 }
1278
1279 static 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
sc16is7xx_gpio_get(struct gpio_chip * chip,unsigned offset)1302 static 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
sc16is7xx_gpio_set(struct gpio_chip * chip,unsigned offset,int val)1313 static 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
sc16is7xx_gpio_direction_input(struct gpio_chip * chip,unsigned offset)1322 static 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
sc16is7xx_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int val)1333 static 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
sc16is7xx_gpio_init_valid_mask(struct gpio_chip * chip,unsigned long * valid_mask,unsigned int ngpios)1360 static 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
sc16is7xx_setup_gpio_chip(struct sc16is7xx_port * s)1371 static 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
sc16is7xx_setup_irda_ports(struct sc16is7xx_port * s)1411 static 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 */
sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port * s,struct regmap * regmap)1437 static 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
1475 static const struct serial_rs485 sc16is7xx_rs485_supported = {
1476 .flags = SER_RS485_ENABLED | 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 */
sc16is7xx_reset(struct device * dev,struct regmap * regmap)1482 static 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
sc16is7xx_probe(struct device * dev,const struct sc16is7xx_devtype * devtype,struct regmap * regmaps[],int irq)1504 int 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
1692 out_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
1700 out_kthread:
1701 kthread_stop(s->kworker_task);
1702
1703 out_clk:
1704 clk_disable_unprepare(s->clk);
1705
1706 return ret;
1707 }
1708 EXPORT_SYMBOL_GPL(sc16is7xx_probe);
1709
sc16is7xx_remove(struct device * dev)1710 void 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 }
1732 EXPORT_SYMBOL_GPL(sc16is7xx_remove);
1733
1734 const 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 };
1743 EXPORT_SYMBOL_GPL(sc16is7xx_dt_ids);
1744 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1745
1746 const 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 };
1759 EXPORT_SYMBOL_GPL(sc16is7xx_regcfg);
1760
sc16is7xx_regmap_name(u8 port_id)1761 const 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 }
1771 EXPORT_SYMBOL_GPL(sc16is7xx_regmap_name);
1772
sc16is7xx_regmap_port_mask(unsigned int port_id)1773 unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
1774 {
1775 /* CH1,CH0 are at bits 2:1. */
1776 return port_id << 1;
1777 }
1778 EXPORT_SYMBOL_GPL(sc16is7xx_regmap_port_mask);
1779
sc16is7xx_init(void)1780 static int __init sc16is7xx_init(void)
1781 {
1782 return uart_register_driver(&sc16is7xx_uart);
1783 }
1784 module_init(sc16is7xx_init);
1785
sc16is7xx_exit(void)1786 static void __exit sc16is7xx_exit(void)
1787 {
1788 uart_unregister_driver(&sc16is7xx_uart);
1789 }
1790 module_exit(sc16is7xx_exit);
1791
1792 MODULE_LICENSE("GPL");
1793 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1794 MODULE_DESCRIPTION("SC16IS7xx tty serial core driver");
1795