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[mirror_ubuntu-bionic-kernel.git] / drivers / tty / serial / sc16is7xx.c
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 << 0) /* CTS */
200 #define SC16IS7XX_MSR_DSR_BIT (1 << 1) /* DSR (IO4)
201 * - only on 75x/76x
202 */
203 #define SC16IS7XX_MSR_RI_BIT (1 << 2) /* RI (IO7)
204 * - only on 75x/76x
205 */
206 #define SC16IS7XX_MSR_CD_BIT (1 << 3) /* 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_GPIO_BIT (1 << 1) /* Enable GPIO[7:4] */
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
301 struct 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
311 struct sc16is7xx_one_config {
312 unsigned int flags;
313 u8 ier_clear;
314 };
315
316 struct 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
324 struct 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
338 static unsigned long sc16is7xx_lines;
339
340 static 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
349 static 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
356 static 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
367 static 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
375 static 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
386 static 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 regcache_cache_bypass(s->regmap, true);
393 regmap_raw_write(s->regmap, addr, s->buf, to_send);
394 regcache_cache_bypass(s->regmap, false);
395 }
396
397 static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
398 u8 mask, u8 val)
399 {
400 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
401 const u8 line = sc16is7xx_line(port);
402
403 regmap_update_bits(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line,
404 mask, val);
405 }
406
407 static int sc16is7xx_alloc_line(void)
408 {
409 int i;
410
411 BUILD_BUG_ON(SC16IS7XX_MAX_DEVS > BITS_PER_LONG);
412
413 for (i = 0; i < SC16IS7XX_MAX_DEVS; i++)
414 if (!test_and_set_bit(i, &sc16is7xx_lines))
415 break;
416
417 return i;
418 }
419
420 static void sc16is7xx_power(struct uart_port *port, int on)
421 {
422 sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
423 SC16IS7XX_IER_SLEEP_BIT,
424 on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
425 }
426
427 static const struct sc16is7xx_devtype sc16is74x_devtype = {
428 .name = "SC16IS74X",
429 .nr_gpio = 0,
430 .nr_uart = 1,
431 };
432
433 static const struct sc16is7xx_devtype sc16is750_devtype = {
434 .name = "SC16IS750",
435 .nr_gpio = 8,
436 .nr_uart = 1,
437 };
438
439 static const struct sc16is7xx_devtype sc16is752_devtype = {
440 .name = "SC16IS752",
441 .nr_gpio = 8,
442 .nr_uart = 2,
443 };
444
445 static const struct sc16is7xx_devtype sc16is760_devtype = {
446 .name = "SC16IS760",
447 .nr_gpio = 8,
448 .nr_uart = 1,
449 };
450
451 static const struct sc16is7xx_devtype sc16is762_devtype = {
452 .name = "SC16IS762",
453 .nr_gpio = 8,
454 .nr_uart = 2,
455 };
456
457 static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
458 {
459 switch (reg >> SC16IS7XX_REG_SHIFT) {
460 case SC16IS7XX_RHR_REG:
461 case SC16IS7XX_IIR_REG:
462 case SC16IS7XX_LSR_REG:
463 case SC16IS7XX_MSR_REG:
464 case SC16IS7XX_TXLVL_REG:
465 case SC16IS7XX_RXLVL_REG:
466 case SC16IS7XX_IOSTATE_REG:
467 return true;
468 default:
469 break;
470 }
471
472 return false;
473 }
474
475 static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
476 {
477 switch (reg >> SC16IS7XX_REG_SHIFT) {
478 case SC16IS7XX_RHR_REG:
479 return true;
480 default:
481 break;
482 }
483
484 return false;
485 }
486
487 static int sc16is7xx_set_baud(struct uart_port *port, int baud)
488 {
489 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
490 u8 lcr;
491 u8 prescaler = 0;
492 unsigned long clk = port->uartclk, div = clk / 16 / baud;
493
494 if (div > 0xffff) {
495 prescaler = SC16IS7XX_MCR_CLKSEL_BIT;
496 div /= 4;
497 }
498
499 lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
500
501 /* Open the LCR divisors for configuration */
502 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
503 SC16IS7XX_LCR_CONF_MODE_B);
504
505 /* Enable enhanced features */
506 regcache_cache_bypass(s->regmap, true);
507 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG,
508 SC16IS7XX_EFR_ENABLE_BIT);
509 regcache_cache_bypass(s->regmap, false);
510
511 /* Put LCR back to the normal mode */
512 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
513
514 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
515 SC16IS7XX_MCR_CLKSEL_BIT,
516 prescaler);
517
518 /* Open the LCR divisors for configuration */
519 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
520 SC16IS7XX_LCR_CONF_MODE_A);
521
522 /* Write the new divisor */
523 regcache_cache_bypass(s->regmap, true);
524 sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
525 sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
526 regcache_cache_bypass(s->regmap, false);
527
528 /* Put LCR back to the normal mode */
529 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
530
531 return DIV_ROUND_CLOSEST(clk / 16, div);
532 }
533
534 static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
535 unsigned int iir)
536 {
537 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
538 unsigned int lsr = 0, ch, flag, bytes_read, i;
539 bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
540
541 if (unlikely(rxlen >= sizeof(s->buf))) {
542 dev_warn_ratelimited(port->dev,
543 "ttySC%i: Possible RX FIFO overrun: %d\n",
544 port->line, rxlen);
545 port->icount.buf_overrun++;
546 /* Ensure sanity of RX level */
547 rxlen = sizeof(s->buf);
548 }
549
550 while (rxlen) {
551 /* Only read lsr if there are possible errors in FIFO */
552 if (read_lsr) {
553 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
554 if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
555 read_lsr = false; /* No errors left in FIFO */
556 } else
557 lsr = 0;
558
559 if (read_lsr) {
560 s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
561 bytes_read = 1;
562 } else {
563 sc16is7xx_fifo_read(port, rxlen);
564 bytes_read = rxlen;
565 }
566
567 lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
568
569 port->icount.rx++;
570 flag = TTY_NORMAL;
571
572 if (unlikely(lsr)) {
573 if (lsr & SC16IS7XX_LSR_BI_BIT) {
574 port->icount.brk++;
575 if (uart_handle_break(port))
576 continue;
577 } else if (lsr & SC16IS7XX_LSR_PE_BIT)
578 port->icount.parity++;
579 else if (lsr & SC16IS7XX_LSR_FE_BIT)
580 port->icount.frame++;
581 else if (lsr & SC16IS7XX_LSR_OE_BIT)
582 port->icount.overrun++;
583
584 lsr &= port->read_status_mask;
585 if (lsr & SC16IS7XX_LSR_BI_BIT)
586 flag = TTY_BREAK;
587 else if (lsr & SC16IS7XX_LSR_PE_BIT)
588 flag = TTY_PARITY;
589 else if (lsr & SC16IS7XX_LSR_FE_BIT)
590 flag = TTY_FRAME;
591 else if (lsr & SC16IS7XX_LSR_OE_BIT)
592 flag = TTY_OVERRUN;
593 }
594
595 for (i = 0; i < bytes_read; ++i) {
596 ch = s->buf[i];
597 if (uart_handle_sysrq_char(port, ch))
598 continue;
599
600 if (lsr & port->ignore_status_mask)
601 continue;
602
603 uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
604 flag);
605 }
606 rxlen -= bytes_read;
607 }
608
609 tty_flip_buffer_push(&port->state->port);
610 }
611
612 static void sc16is7xx_handle_tx(struct uart_port *port)
613 {
614 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
615 struct circ_buf *xmit = &port->state->xmit;
616 unsigned int txlen, to_send, i;
617
618 if (unlikely(port->x_char)) {
619 sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
620 port->icount.tx++;
621 port->x_char = 0;
622 return;
623 }
624
625 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
626 return;
627
628 /* Get length of data pending in circular buffer */
629 to_send = uart_circ_chars_pending(xmit);
630 if (likely(to_send)) {
631 /* Limit to size of TX FIFO */
632 txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
633 to_send = (to_send > txlen) ? txlen : to_send;
634
635 /* Add data to send */
636 port->icount.tx += to_send;
637
638 /* Convert to linear buffer */
639 for (i = 0; i < to_send; ++i) {
640 s->buf[i] = xmit->buf[xmit->tail];
641 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
642 }
643
644 sc16is7xx_fifo_write(port, to_send);
645 }
646
647 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
648 uart_write_wakeup(port);
649 }
650
651 static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
652 {
653 struct uart_port *port = &s->p[portno].port;
654
655 do {
656 unsigned int iir, msr, rxlen;
657
658 iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
659 if (iir & SC16IS7XX_IIR_NO_INT_BIT)
660 break;
661
662 iir &= SC16IS7XX_IIR_ID_MASK;
663
664 switch (iir) {
665 case SC16IS7XX_IIR_RDI_SRC:
666 case SC16IS7XX_IIR_RLSE_SRC:
667 case SC16IS7XX_IIR_RTOI_SRC:
668 case SC16IS7XX_IIR_XOFFI_SRC:
669 rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
670 if (rxlen)
671 sc16is7xx_handle_rx(port, rxlen, iir);
672 break;
673
674 case SC16IS7XX_IIR_CTSRTS_SRC:
675 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
676 uart_handle_cts_change(port,
677 !!(msr & SC16IS7XX_MSR_CTS_BIT));
678 break;
679 case SC16IS7XX_IIR_THRI_SRC:
680 sc16is7xx_handle_tx(port);
681 break;
682 default:
683 dev_err_ratelimited(port->dev,
684 "ttySC%i: Unexpected interrupt: %x",
685 port->line, iir);
686 break;
687 }
688 } while (1);
689 }
690
691 static void sc16is7xx_ist(struct kthread_work *ws)
692 {
693 struct sc16is7xx_port *s = to_sc16is7xx_port(ws, irq_work);
694 int i;
695
696 for (i = 0; i < s->devtype->nr_uart; ++i)
697 sc16is7xx_port_irq(s, i);
698 }
699
700 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
701 {
702 struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
703
704 queue_kthread_work(&s->kworker, &s->irq_work);
705
706 return IRQ_HANDLED;
707 }
708
709 static void sc16is7xx_tx_proc(struct kthread_work *ws)
710 {
711 struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
712
713 if ((port->rs485.flags & SER_RS485_ENABLED) &&
714 (port->rs485.delay_rts_before_send > 0))
715 msleep(port->rs485.delay_rts_before_send);
716
717 sc16is7xx_handle_tx(port);
718 }
719
720 static void sc16is7xx_reconf_rs485(struct uart_port *port)
721 {
722 const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
723 SC16IS7XX_EFCR_RTS_INVERT_BIT;
724 u32 efcr = 0;
725 struct serial_rs485 *rs485 = &port->rs485;
726 unsigned long irqflags;
727
728 spin_lock_irqsave(&port->lock, irqflags);
729 if (rs485->flags & SER_RS485_ENABLED) {
730 efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT;
731
732 if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
733 efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
734 }
735 spin_unlock_irqrestore(&port->lock, irqflags);
736
737 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
738 }
739
740 static void sc16is7xx_reg_proc(struct kthread_work *ws)
741 {
742 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
743 struct sc16is7xx_one_config config;
744 unsigned long irqflags;
745
746 spin_lock_irqsave(&one->port.lock, irqflags);
747 config = one->config;
748 memset(&one->config, 0, sizeof(one->config));
749 spin_unlock_irqrestore(&one->port.lock, irqflags);
750
751 if (config.flags & SC16IS7XX_RECONF_MD)
752 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
753 SC16IS7XX_MCR_LOOP_BIT,
754 (one->port.mctrl & TIOCM_LOOP) ?
755 SC16IS7XX_MCR_LOOP_BIT : 0);
756
757 if (config.flags & SC16IS7XX_RECONF_IER)
758 sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
759 config.ier_clear, 0);
760
761 if (config.flags & SC16IS7XX_RECONF_RS485)
762 sc16is7xx_reconf_rs485(&one->port);
763 }
764
765 static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
766 {
767 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
768 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
769
770 one->config.flags |= SC16IS7XX_RECONF_IER;
771 one->config.ier_clear |= bit;
772 queue_kthread_work(&s->kworker, &one->reg_work);
773 }
774
775 static void sc16is7xx_stop_tx(struct uart_port *port)
776 {
777 sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
778 }
779
780 static void sc16is7xx_stop_rx(struct uart_port *port)
781 {
782 sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
783 }
784
785 static void sc16is7xx_start_tx(struct uart_port *port)
786 {
787 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
788 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
789
790 queue_kthread_work(&s->kworker, &one->tx_work);
791 }
792
793 static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
794 {
795 unsigned int lsr;
796
797 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
798
799 return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
800 }
801
802 static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
803 {
804 /* DCD and DSR are not wired and CTS/RTS is handled automatically
805 * so just indicate DSR and CAR asserted
806 */
807 return TIOCM_DSR | TIOCM_CAR;
808 }
809
810 static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
811 {
812 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
813 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
814
815 one->config.flags |= SC16IS7XX_RECONF_MD;
816 queue_kthread_work(&s->kworker, &one->reg_work);
817 }
818
819 static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
820 {
821 sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
822 SC16IS7XX_LCR_TXBREAK_BIT,
823 break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
824 }
825
826 static void sc16is7xx_set_termios(struct uart_port *port,
827 struct ktermios *termios,
828 struct ktermios *old)
829 {
830 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
831 unsigned int lcr, flow = 0;
832 int baud;
833
834 /* Mask termios capabilities we don't support */
835 termios->c_cflag &= ~CMSPAR;
836
837 /* Word size */
838 switch (termios->c_cflag & CSIZE) {
839 case CS5:
840 lcr = SC16IS7XX_LCR_WORD_LEN_5;
841 break;
842 case CS6:
843 lcr = SC16IS7XX_LCR_WORD_LEN_6;
844 break;
845 case CS7:
846 lcr = SC16IS7XX_LCR_WORD_LEN_7;
847 break;
848 case CS8:
849 lcr = SC16IS7XX_LCR_WORD_LEN_8;
850 break;
851 default:
852 lcr = SC16IS7XX_LCR_WORD_LEN_8;
853 termios->c_cflag &= ~CSIZE;
854 termios->c_cflag |= CS8;
855 break;
856 }
857
858 /* Parity */
859 if (termios->c_cflag & PARENB) {
860 lcr |= SC16IS7XX_LCR_PARITY_BIT;
861 if (!(termios->c_cflag & PARODD))
862 lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
863 }
864
865 /* Stop bits */
866 if (termios->c_cflag & CSTOPB)
867 lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
868
869 /* Set read status mask */
870 port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
871 if (termios->c_iflag & INPCK)
872 port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
873 SC16IS7XX_LSR_FE_BIT;
874 if (termios->c_iflag & (BRKINT | PARMRK))
875 port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
876
877 /* Set status ignore mask */
878 port->ignore_status_mask = 0;
879 if (termios->c_iflag & IGNBRK)
880 port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
881 if (!(termios->c_cflag & CREAD))
882 port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
883
884 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
885 SC16IS7XX_LCR_CONF_MODE_B);
886
887 /* Configure flow control */
888 regcache_cache_bypass(s->regmap, true);
889 sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
890 sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
891 if (termios->c_cflag & CRTSCTS)
892 flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
893 SC16IS7XX_EFR_AUTORTS_BIT;
894 if (termios->c_iflag & IXON)
895 flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
896 if (termios->c_iflag & IXOFF)
897 flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
898
899 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, flow);
900 regcache_cache_bypass(s->regmap, false);
901
902 /* Update LCR register */
903 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
904
905 /* Get baud rate generator configuration */
906 baud = uart_get_baud_rate(port, termios, old,
907 port->uartclk / 16 / 4 / 0xffff,
908 port->uartclk / 16);
909
910 /* Setup baudrate generator */
911 baud = sc16is7xx_set_baud(port, baud);
912
913 /* Update timeout according to new baud rate */
914 uart_update_timeout(port, termios->c_cflag, baud);
915 }
916
917 static int sc16is7xx_config_rs485(struct uart_port *port,
918 struct serial_rs485 *rs485)
919 {
920 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
921 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
922
923 if (rs485->flags & SER_RS485_ENABLED) {
924 bool rts_during_rx, rts_during_tx;
925
926 rts_during_rx = rs485->flags & SER_RS485_RTS_AFTER_SEND;
927 rts_during_tx = rs485->flags & SER_RS485_RTS_ON_SEND;
928
929 if (rts_during_rx == rts_during_tx)
930 dev_err(port->dev,
931 "unsupported RTS signalling on_send:%d after_send:%d - exactly one of RS485 RTS flags should be set\n",
932 rts_during_tx, rts_during_rx);
933
934 /*
935 * RTS signal is handled by HW, it's timing can't be influenced.
936 * However, it's sometimes useful to delay TX even without RTS
937 * control therefore we try to handle .delay_rts_before_send.
938 */
939 if (rs485->delay_rts_after_send)
940 return -EINVAL;
941 }
942
943 port->rs485 = *rs485;
944 one->config.flags |= SC16IS7XX_RECONF_RS485;
945 queue_kthread_work(&s->kworker, &one->reg_work);
946
947 return 0;
948 }
949
950 static int sc16is7xx_startup(struct uart_port *port)
951 {
952 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
953 unsigned int val;
954
955 sc16is7xx_power(port, 1);
956
957 /* Reset FIFOs*/
958 val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
959 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
960 udelay(5);
961 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
962 SC16IS7XX_FCR_FIFO_BIT);
963
964 /* Enable EFR */
965 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
966 SC16IS7XX_LCR_CONF_MODE_B);
967
968 regcache_cache_bypass(s->regmap, true);
969
970 /* Enable write access to enhanced features and internal clock div */
971 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG,
972 SC16IS7XX_EFR_ENABLE_BIT);
973
974 /* Enable TCR/TLR */
975 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
976 SC16IS7XX_MCR_TCRTLR_BIT,
977 SC16IS7XX_MCR_TCRTLR_BIT);
978
979 /* Configure flow control levels */
980 /* Flow control halt level 48, resume level 24 */
981 sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
982 SC16IS7XX_TCR_RX_RESUME(24) |
983 SC16IS7XX_TCR_RX_HALT(48));
984
985 regcache_cache_bypass(s->regmap, false);
986
987 /* Now, initialize the UART */
988 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
989
990 /* Enable the Rx and Tx FIFO */
991 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
992 SC16IS7XX_EFCR_RXDISABLE_BIT |
993 SC16IS7XX_EFCR_TXDISABLE_BIT,
994 0);
995
996 /* Enable RX, TX, CTS change interrupts */
997 val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_THRI_BIT |
998 SC16IS7XX_IER_CTSI_BIT;
999 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1000
1001 return 0;
1002 }
1003
1004 static void sc16is7xx_shutdown(struct uart_port *port)
1005 {
1006 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1007
1008 /* Disable all interrupts */
1009 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1010 /* Disable TX/RX */
1011 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1012 SC16IS7XX_EFCR_RXDISABLE_BIT |
1013 SC16IS7XX_EFCR_TXDISABLE_BIT,
1014 SC16IS7XX_EFCR_RXDISABLE_BIT |
1015 SC16IS7XX_EFCR_TXDISABLE_BIT);
1016
1017 sc16is7xx_power(port, 0);
1018
1019 flush_kthread_worker(&s->kworker);
1020 }
1021
1022 static const char *sc16is7xx_type(struct uart_port *port)
1023 {
1024 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1025
1026 return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1027 }
1028
1029 static int sc16is7xx_request_port(struct uart_port *port)
1030 {
1031 /* Do nothing */
1032 return 0;
1033 }
1034
1035 static void sc16is7xx_config_port(struct uart_port *port, int flags)
1036 {
1037 if (flags & UART_CONFIG_TYPE)
1038 port->type = PORT_SC16IS7XX;
1039 }
1040
1041 static int sc16is7xx_verify_port(struct uart_port *port,
1042 struct serial_struct *s)
1043 {
1044 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1045 return -EINVAL;
1046 if (s->irq != port->irq)
1047 return -EINVAL;
1048
1049 return 0;
1050 }
1051
1052 static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1053 unsigned int oldstate)
1054 {
1055 sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1056 }
1057
1058 static void sc16is7xx_null_void(struct uart_port *port)
1059 {
1060 /* Do nothing */
1061 }
1062
1063 static const struct uart_ops sc16is7xx_ops = {
1064 .tx_empty = sc16is7xx_tx_empty,
1065 .set_mctrl = sc16is7xx_set_mctrl,
1066 .get_mctrl = sc16is7xx_get_mctrl,
1067 .stop_tx = sc16is7xx_stop_tx,
1068 .start_tx = sc16is7xx_start_tx,
1069 .stop_rx = sc16is7xx_stop_rx,
1070 .break_ctl = sc16is7xx_break_ctl,
1071 .startup = sc16is7xx_startup,
1072 .shutdown = sc16is7xx_shutdown,
1073 .set_termios = sc16is7xx_set_termios,
1074 .type = sc16is7xx_type,
1075 .request_port = sc16is7xx_request_port,
1076 .release_port = sc16is7xx_null_void,
1077 .config_port = sc16is7xx_config_port,
1078 .verify_port = sc16is7xx_verify_port,
1079 .pm = sc16is7xx_pm,
1080 };
1081
1082 #ifdef CONFIG_GPIOLIB
1083 static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1084 {
1085 unsigned int val;
1086 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1087 gpio);
1088 struct uart_port *port = &s->p[0].port;
1089
1090 val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1091
1092 return !!(val & BIT(offset));
1093 }
1094
1095 static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1096 {
1097 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1098 gpio);
1099 struct uart_port *port = &s->p[0].port;
1100
1101 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1102 val ? BIT(offset) : 0);
1103 }
1104
1105 static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1106 unsigned offset)
1107 {
1108 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1109 gpio);
1110 struct uart_port *port = &s->p[0].port;
1111
1112 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1113
1114 return 0;
1115 }
1116
1117 static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1118 unsigned offset, int val)
1119 {
1120 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1121 gpio);
1122 struct uart_port *port = &s->p[0].port;
1123
1124 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1125 val ? BIT(offset) : 0);
1126 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1127 BIT(offset));
1128
1129 return 0;
1130 }
1131 #endif
1132
1133 static int sc16is7xx_probe(struct device *dev,
1134 const struct sc16is7xx_devtype *devtype,
1135 struct regmap *regmap, int irq, unsigned long flags)
1136 {
1137 struct sched_param sched_param = { .sched_priority = MAX_RT_PRIO / 2 };
1138 unsigned long freq, *pfreq = dev_get_platdata(dev);
1139 int i, ret;
1140 struct sc16is7xx_port *s;
1141
1142 if (IS_ERR(regmap))
1143 return PTR_ERR(regmap);
1144
1145 /* Alloc port structure */
1146 s = devm_kzalloc(dev, sizeof(*s) +
1147 sizeof(struct sc16is7xx_one) * devtype->nr_uart,
1148 GFP_KERNEL);
1149 if (!s) {
1150 dev_err(dev, "Error allocating port structure\n");
1151 return -ENOMEM;
1152 }
1153
1154 s->clk = devm_clk_get(dev, NULL);
1155 if (IS_ERR(s->clk)) {
1156 if (pfreq)
1157 freq = *pfreq;
1158 else
1159 return PTR_ERR(s->clk);
1160 } else {
1161 clk_prepare_enable(s->clk);
1162 freq = clk_get_rate(s->clk);
1163 }
1164
1165 s->regmap = regmap;
1166 s->devtype = devtype;
1167 dev_set_drvdata(dev, s);
1168
1169 init_kthread_worker(&s->kworker);
1170 init_kthread_work(&s->irq_work, sc16is7xx_ist);
1171 s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1172 "sc16is7xx");
1173 if (IS_ERR(s->kworker_task)) {
1174 ret = PTR_ERR(s->kworker_task);
1175 goto out_clk;
1176 }
1177 sched_setscheduler(s->kworker_task, SCHED_FIFO, &sched_param);
1178
1179 #ifdef CONFIG_GPIOLIB
1180 if (devtype->nr_gpio) {
1181 /* Setup GPIO cotroller */
1182 s->gpio.owner = THIS_MODULE;
1183 s->gpio.dev = dev;
1184 s->gpio.label = dev_name(dev);
1185 s->gpio.direction_input = sc16is7xx_gpio_direction_input;
1186 s->gpio.get = sc16is7xx_gpio_get;
1187 s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1188 s->gpio.set = sc16is7xx_gpio_set;
1189 s->gpio.base = -1;
1190 s->gpio.ngpio = devtype->nr_gpio;
1191 s->gpio.can_sleep = 1;
1192 ret = gpiochip_add(&s->gpio);
1193 if (ret)
1194 goto out_thread;
1195 }
1196 #endif
1197
1198 for (i = 0; i < devtype->nr_uart; ++i) {
1199 s->p[i].line = i;
1200 /* Initialize port data */
1201 s->p[i].port.dev = dev;
1202 s->p[i].port.irq = irq;
1203 s->p[i].port.type = PORT_SC16IS7XX;
1204 s->p[i].port.fifosize = SC16IS7XX_FIFO_SIZE;
1205 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1206 s->p[i].port.iotype = UPIO_PORT;
1207 s->p[i].port.uartclk = freq;
1208 s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1209 s->p[i].port.ops = &sc16is7xx_ops;
1210 s->p[i].port.line = sc16is7xx_alloc_line();
1211 if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
1212 ret = -ENOMEM;
1213 goto out_ports;
1214 }
1215
1216 /* Disable all interrupts */
1217 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1218 /* Disable TX/RX */
1219 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1220 SC16IS7XX_EFCR_RXDISABLE_BIT |
1221 SC16IS7XX_EFCR_TXDISABLE_BIT);
1222 /* Initialize kthread work structs */
1223 init_kthread_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1224 init_kthread_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1225 /* Register port */
1226 uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1227 /* Go to suspend mode */
1228 sc16is7xx_power(&s->p[i].port, 0);
1229 }
1230
1231 /* Setup interrupt */
1232 ret = devm_request_irq(dev, irq, sc16is7xx_irq,
1233 IRQF_ONESHOT | flags, dev_name(dev), s);
1234 if (!ret)
1235 return 0;
1236
1237 out_ports:
1238 for (i--; i >= 0; i--) {
1239 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1240 clear_bit(s->p[i].port.line, &sc16is7xx_lines);
1241 }
1242
1243 #ifdef CONFIG_GPIOLIB
1244 if (devtype->nr_gpio)
1245 gpiochip_remove(&s->gpio);
1246
1247 out_thread:
1248 #endif
1249 kthread_stop(s->kworker_task);
1250
1251 out_clk:
1252 if (!IS_ERR(s->clk))
1253 clk_disable_unprepare(s->clk);
1254
1255 return ret;
1256 }
1257
1258 static int sc16is7xx_remove(struct device *dev)
1259 {
1260 struct sc16is7xx_port *s = dev_get_drvdata(dev);
1261 int i;
1262
1263 #ifdef CONFIG_GPIOLIB
1264 if (s->devtype->nr_gpio)
1265 gpiochip_remove(&s->gpio);
1266 #endif
1267
1268 for (i = 0; i < s->devtype->nr_uart; i++) {
1269 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1270 clear_bit(s->p[i].port.line, &sc16is7xx_lines);
1271 sc16is7xx_power(&s->p[i].port, 0);
1272 }
1273
1274 flush_kthread_worker(&s->kworker);
1275 kthread_stop(s->kworker_task);
1276
1277 if (!IS_ERR(s->clk))
1278 clk_disable_unprepare(s->clk);
1279
1280 return 0;
1281 }
1282
1283 static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1284 { .compatible = "nxp,sc16is740", .data = &sc16is74x_devtype, },
1285 { .compatible = "nxp,sc16is741", .data = &sc16is74x_devtype, },
1286 { .compatible = "nxp,sc16is750", .data = &sc16is750_devtype, },
1287 { .compatible = "nxp,sc16is752", .data = &sc16is752_devtype, },
1288 { .compatible = "nxp,sc16is760", .data = &sc16is760_devtype, },
1289 { .compatible = "nxp,sc16is762", .data = &sc16is762_devtype, },
1290 { }
1291 };
1292 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1293
1294 static struct regmap_config regcfg = {
1295 .reg_bits = 7,
1296 .pad_bits = 1,
1297 .val_bits = 8,
1298 .cache_type = REGCACHE_RBTREE,
1299 .volatile_reg = sc16is7xx_regmap_volatile,
1300 .precious_reg = sc16is7xx_regmap_precious,
1301 };
1302
1303 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1304 static int sc16is7xx_spi_probe(struct spi_device *spi)
1305 {
1306 const struct sc16is7xx_devtype *devtype;
1307 unsigned long flags = 0;
1308 struct regmap *regmap;
1309 int ret;
1310
1311 /* Setup SPI bus */
1312 spi->bits_per_word = 8;
1313 /* only supports mode 0 on SC16IS762 */
1314 spi->mode = spi->mode ? : SPI_MODE_0;
1315 spi->max_speed_hz = spi->max_speed_hz ? : 15000000;
1316 ret = spi_setup(spi);
1317 if (ret)
1318 return ret;
1319
1320 if (spi->dev.of_node) {
1321 const struct of_device_id *of_id =
1322 of_match_device(sc16is7xx_dt_ids, &spi->dev);
1323
1324 if (!of_id)
1325 return -ENODEV;
1326
1327 devtype = (struct sc16is7xx_devtype *)of_id->data;
1328 } else {
1329 const struct spi_device_id *id_entry = spi_get_device_id(spi);
1330
1331 devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
1332 flags = IRQF_TRIGGER_FALLING;
1333 }
1334
1335 regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1336 (devtype->nr_uart - 1);
1337 regmap = devm_regmap_init_spi(spi, &regcfg);
1338
1339 return sc16is7xx_probe(&spi->dev, devtype, regmap, spi->irq, flags);
1340 }
1341
1342 static int sc16is7xx_spi_remove(struct spi_device *spi)
1343 {
1344 return sc16is7xx_remove(&spi->dev);
1345 }
1346
1347 static const struct spi_device_id sc16is7xx_spi_id_table[] = {
1348 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1349 { "sc16is740", (kernel_ulong_t)&sc16is74x_devtype, },
1350 { "sc16is741", (kernel_ulong_t)&sc16is74x_devtype, },
1351 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1352 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1353 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1354 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1355 { }
1356 };
1357
1358 MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
1359
1360 static struct spi_driver sc16is7xx_spi_uart_driver = {
1361 .driver = {
1362 .name = SC16IS7XX_NAME,
1363 .of_match_table = of_match_ptr(sc16is7xx_dt_ids),
1364 },
1365 .probe = sc16is7xx_spi_probe,
1366 .remove = sc16is7xx_spi_remove,
1367 .id_table = sc16is7xx_spi_id_table,
1368 };
1369
1370 MODULE_ALIAS("spi:sc16is7xx");
1371 #endif
1372
1373 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1374 static int sc16is7xx_i2c_probe(struct i2c_client *i2c,
1375 const struct i2c_device_id *id)
1376 {
1377 const struct sc16is7xx_devtype *devtype;
1378 unsigned long flags = 0;
1379 struct regmap *regmap;
1380
1381 if (i2c->dev.of_node) {
1382 const struct of_device_id *of_id =
1383 of_match_device(sc16is7xx_dt_ids, &i2c->dev);
1384
1385 if (!of_id)
1386 return -ENODEV;
1387
1388 devtype = (struct sc16is7xx_devtype *)of_id->data;
1389 } else {
1390 devtype = (struct sc16is7xx_devtype *)id->driver_data;
1391 flags = IRQF_TRIGGER_FALLING;
1392 }
1393
1394 regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1395 (devtype->nr_uart - 1);
1396 regmap = devm_regmap_init_i2c(i2c, &regcfg);
1397
1398 return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq, flags);
1399 }
1400
1401 static int sc16is7xx_i2c_remove(struct i2c_client *client)
1402 {
1403 return sc16is7xx_remove(&client->dev);
1404 }
1405
1406 static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
1407 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1408 { "sc16is740", (kernel_ulong_t)&sc16is74x_devtype, },
1409 { "sc16is741", (kernel_ulong_t)&sc16is74x_devtype, },
1410 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1411 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1412 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1413 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1414 { }
1415 };
1416 MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
1417
1418 static struct i2c_driver sc16is7xx_i2c_uart_driver = {
1419 .driver = {
1420 .name = SC16IS7XX_NAME,
1421 .of_match_table = of_match_ptr(sc16is7xx_dt_ids),
1422 },
1423 .probe = sc16is7xx_i2c_probe,
1424 .remove = sc16is7xx_i2c_remove,
1425 .id_table = sc16is7xx_i2c_id_table,
1426 };
1427
1428 #endif
1429
1430 static int __init sc16is7xx_init(void)
1431 {
1432 int ret;
1433
1434 ret = uart_register_driver(&sc16is7xx_uart);
1435 if (ret) {
1436 pr_err("Registering UART driver failed\n");
1437 return ret;
1438 }
1439
1440 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1441 ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
1442 if (ret < 0) {
1443 pr_err("failed to init sc16is7xx i2c --> %d\n", ret);
1444 return ret;
1445 }
1446 #endif
1447
1448 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1449 ret = spi_register_driver(&sc16is7xx_spi_uart_driver);
1450 if (ret < 0) {
1451 pr_err("failed to init sc16is7xx spi --> %d\n", ret);
1452 return ret;
1453 }
1454 #endif
1455 return ret;
1456 }
1457 module_init(sc16is7xx_init);
1458
1459 static void __exit sc16is7xx_exit(void)
1460 {
1461 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1462 i2c_del_driver(&sc16is7xx_i2c_uart_driver);
1463 #endif
1464
1465 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1466 spi_unregister_driver(&sc16is7xx_spi_uart_driver);
1467 #endif
1468 uart_unregister_driver(&sc16is7xx_uart);
1469 }
1470 module_exit(sc16is7xx_exit);
1471
1472 MODULE_LICENSE("GPL");
1473 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1474 MODULE_DESCRIPTION("SC16IS7XX serial driver");
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