1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * SC16IS7xx tty serial driver - Copyright (C) 2014 GridPoint
4 * Author: Jon Ringle <jringle@gridpoint.com>
5 *
6 * Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/bitops.h>
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/gpio/driver.h>
16 #include <linux/i2c.h>
17 #include <linux/mod_devicetable.h>
18 #include <linux/module.h>
19 #include <linux/property.h>
20 #include <linux/regmap.h>
21 #include <linux/sched.h>
22 #include <linux/serial_core.h>
23 #include <linux/serial.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/spi/spi.h>
27 #include <linux/uaccess.h>
28 #include <linux/units.h>
29
30 #define SC16IS7XX_NAME "sc16is7xx"
31 #define SC16IS7XX_MAX_DEVS 8
32
33 /* SC16IS7XX register definitions */
34 #define SC16IS7XX_RHR_REG (0x00) /* RX FIFO */
35 #define SC16IS7XX_THR_REG (0x00) /* TX FIFO */
36 #define SC16IS7XX_IER_REG (0x01) /* Interrupt enable */
37 #define SC16IS7XX_IIR_REG (0x02) /* Interrupt Identification */
38 #define SC16IS7XX_FCR_REG (0x02) /* FIFO control */
39 #define SC16IS7XX_LCR_REG (0x03) /* Line Control */
40 #define SC16IS7XX_MCR_REG (0x04) /* Modem Control */
41 #define SC16IS7XX_LSR_REG (0x05) /* Line Status */
42 #define SC16IS7XX_MSR_REG (0x06) /* Modem Status */
43 #define SC16IS7XX_SPR_REG (0x07) /* Scratch Pad */
44 #define SC16IS7XX_TXLVL_REG (0x08) /* TX FIFO level */
45 #define SC16IS7XX_RXLVL_REG (0x09) /* RX FIFO level */
46 #define SC16IS7XX_IODIR_REG (0x0a) /* I/O Direction
47 * - only on 75x/76x
48 */
49 #define SC16IS7XX_IOSTATE_REG (0x0b) /* I/O State
50 * - only on 75x/76x
51 */
52 #define SC16IS7XX_IOINTENA_REG (0x0c) /* I/O Interrupt Enable
53 * - only on 75x/76x
54 */
55 #define SC16IS7XX_IOCONTROL_REG (0x0e) /* I/O Control
56 * - only on 75x/76x
57 */
58 #define SC16IS7XX_EFCR_REG (0x0f) /* Extra Features Control */
59
60 /* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
61 #define SC16IS7XX_TCR_REG (0x06) /* Transmit control */
62 #define SC16IS7XX_TLR_REG (0x07) /* Trigger level */
63
64 /* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
65 #define SC16IS7XX_DLL_REG (0x00) /* Divisor Latch Low */
66 #define SC16IS7XX_DLH_REG (0x01) /* Divisor Latch High */
67
68 /* Enhanced Register set: Only if (LCR == 0xBF) */
69 #define SC16IS7XX_EFR_REG (0x02) /* Enhanced Features */
70 #define SC16IS7XX_XON1_REG (0x04) /* Xon1 word */
71 #define SC16IS7XX_XON2_REG (0x05) /* Xon2 word */
72 #define SC16IS7XX_XOFF1_REG (0x06) /* Xoff1 word */
73 #define SC16IS7XX_XOFF2_REG (0x07) /* Xoff2 word */
74
75 /* IER register bits */
76 #define SC16IS7XX_IER_RDI_BIT (1 << 0) /* Enable RX data interrupt */
77 #define SC16IS7XX_IER_THRI_BIT (1 << 1) /* Enable TX holding register
78 * interrupt */
79 #define SC16IS7XX_IER_RLSI_BIT (1 << 2) /* Enable RX line status
80 * interrupt */
81 #define SC16IS7XX_IER_MSI_BIT (1 << 3) /* Enable Modem status
82 * interrupt */
83
84 /* IER register bits - write only if (EFR[4] == 1) */
85 #define SC16IS7XX_IER_SLEEP_BIT (1 << 4) /* Enable Sleep mode */
86 #define SC16IS7XX_IER_XOFFI_BIT (1 << 5) /* Enable Xoff interrupt */
87 #define SC16IS7XX_IER_RTSI_BIT (1 << 6) /* Enable nRTS interrupt */
88 #define SC16IS7XX_IER_CTSI_BIT (1 << 7) /* Enable nCTS interrupt */
89
90 /* FCR register bits */
91 #define SC16IS7XX_FCR_FIFO_BIT (1 << 0) /* Enable FIFO */
92 #define SC16IS7XX_FCR_RXRESET_BIT (1 << 1) /* Reset RX FIFO */
93 #define SC16IS7XX_FCR_TXRESET_BIT (1 << 2) /* Reset TX FIFO */
94 #define SC16IS7XX_FCR_RXLVLL_BIT (1 << 6) /* RX Trigger level LSB */
95 #define SC16IS7XX_FCR_RXLVLH_BIT (1 << 7) /* RX Trigger level MSB */
96
97 /* FCR register bits - write only if (EFR[4] == 1) */
98 #define SC16IS7XX_FCR_TXLVLL_BIT (1 << 4) /* TX Trigger level LSB */
99 #define SC16IS7XX_FCR_TXLVLH_BIT (1 << 5) /* TX Trigger level MSB */
100
101 /* IIR register bits */
102 #define SC16IS7XX_IIR_NO_INT_BIT (1 << 0) /* No interrupts pending */
103 #define SC16IS7XX_IIR_ID_MASK 0x3e /* Mask for the interrupt ID */
104 #define SC16IS7XX_IIR_THRI_SRC 0x02 /* TX holding register empty */
105 #define SC16IS7XX_IIR_RDI_SRC 0x04 /* RX data interrupt */
106 #define SC16IS7XX_IIR_RLSE_SRC 0x06 /* RX line status error */
107 #define SC16IS7XX_IIR_RTOI_SRC 0x0c /* RX time-out interrupt */
108 #define SC16IS7XX_IIR_MSI_SRC 0x00 /* Modem status interrupt
109 * - only on 75x/76x
110 */
111 #define SC16IS7XX_IIR_INPIN_SRC 0x30 /* Input pin change of state
112 * - only on 75x/76x
113 */
114 #define SC16IS7XX_IIR_XOFFI_SRC 0x10 /* Received Xoff */
115 #define SC16IS7XX_IIR_CTSRTS_SRC 0x20 /* nCTS,nRTS change of state
116 * from active (LOW)
117 * to inactive (HIGH)
118 */
119 /* LCR register bits */
120 #define SC16IS7XX_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */
121 #define SC16IS7XX_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1
122 *
123 * Word length bits table:
124 * 00 -> 5 bit words
125 * 01 -> 6 bit words
126 * 10 -> 7 bit words
127 * 11 -> 8 bit words
128 */
129 #define SC16IS7XX_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
130 *
131 * STOP length bit table:
132 * 0 -> 1 stop bit
133 * 1 -> 1-1.5 stop bits if
134 * word length is 5,
135 * 2 stop bits otherwise
136 */
137 #define SC16IS7XX_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */
138 #define SC16IS7XX_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */
139 #define SC16IS7XX_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */
140 #define SC16IS7XX_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */
141 #define SC16IS7XX_LCR_DLAB_BIT (1 << 7) /* Divisor Latch enable */
142 #define SC16IS7XX_LCR_WORD_LEN_5 (0x00)
143 #define SC16IS7XX_LCR_WORD_LEN_6 (0x01)
144 #define SC16IS7XX_LCR_WORD_LEN_7 (0x02)
145 #define SC16IS7XX_LCR_WORD_LEN_8 (0x03)
146 #define SC16IS7XX_LCR_CONF_MODE_A SC16IS7XX_LCR_DLAB_BIT /* Special
147 * reg set */
148 #define SC16IS7XX_LCR_CONF_MODE_B 0xBF /* Enhanced
149 * reg set */
150
151 /* MCR register bits */
152 #define SC16IS7XX_MCR_DTR_BIT (1 << 0) /* DTR complement
153 * - only on 75x/76x
154 */
155 #define SC16IS7XX_MCR_RTS_BIT (1 << 1) /* RTS complement */
156 #define SC16IS7XX_MCR_TCRTLR_BIT (1 << 2) /* TCR/TLR register enable */
157 #define SC16IS7XX_MCR_LOOP_BIT (1 << 4) /* Enable loopback test mode */
158 #define SC16IS7XX_MCR_XONANY_BIT (1 << 5) /* Enable Xon Any
159 * - write enabled
160 * if (EFR[4] == 1)
161 */
162 #define SC16IS7XX_MCR_IRDA_BIT (1 << 6) /* Enable IrDA mode
163 * - write enabled
164 * if (EFR[4] == 1)
165 */
166 #define SC16IS7XX_MCR_CLKSEL_BIT (1 << 7) /* Divide clock by 4
167 * - write enabled
168 * if (EFR[4] == 1)
169 */
170
171 /* LSR register bits */
172 #define SC16IS7XX_LSR_DR_BIT (1 << 0) /* Receiver data ready */
173 #define SC16IS7XX_LSR_OE_BIT (1 << 1) /* Overrun Error */
174 #define SC16IS7XX_LSR_PE_BIT (1 << 2) /* Parity Error */
175 #define SC16IS7XX_LSR_FE_BIT (1 << 3) /* Frame Error */
176 #define SC16IS7XX_LSR_BI_BIT (1 << 4) /* Break Interrupt */
177 #define SC16IS7XX_LSR_BRK_ERROR_MASK 0x1E /* BI, FE, PE, OE bits */
178 #define SC16IS7XX_LSR_THRE_BIT (1 << 5) /* TX holding register empty */
179 #define SC16IS7XX_LSR_TEMT_BIT (1 << 6) /* Transmitter empty */
180 #define SC16IS7XX_LSR_FIFOE_BIT (1 << 7) /* Fifo Error */
181
182 /* MSR register bits */
183 #define SC16IS7XX_MSR_DCTS_BIT (1 << 0) /* Delta CTS Clear To Send */
184 #define SC16IS7XX_MSR_DDSR_BIT (1 << 1) /* Delta DSR Data Set Ready
185 * or (IO4)
186 * - only on 75x/76x
187 */
188 #define SC16IS7XX_MSR_DRI_BIT (1 << 2) /* Delta RI Ring Indicator
189 * or (IO7)
190 * - only on 75x/76x
191 */
192 #define SC16IS7XX_MSR_DCD_BIT (1 << 3) /* Delta CD Carrier Detect
193 * or (IO6)
194 * - only on 75x/76x
195 */
196 #define SC16IS7XX_MSR_CTS_BIT (1 << 4) /* CTS */
197 #define SC16IS7XX_MSR_DSR_BIT (1 << 5) /* DSR (IO4)
198 * - only on 75x/76x
199 */
200 #define SC16IS7XX_MSR_RI_BIT (1 << 6) /* RI (IO7)
201 * - only on 75x/76x
202 */
203 #define SC16IS7XX_MSR_CD_BIT (1 << 7) /* CD (IO6)
204 * - only on 75x/76x
205 */
206 #define SC16IS7XX_MSR_DELTA_MASK 0x0F /* Any of the delta bits! */
207
208 /*
209 * TCR register bits
210 * TCR trigger levels are available from 0 to 60 characters with a granularity
211 * of four.
212 * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
213 * no built-in hardware check to make sure this condition is met. Also, the TCR
214 * must be programmed with this condition before auto RTS or software flow
215 * control is enabled to avoid spurious operation of the device.
216 */
217 #define SC16IS7XX_TCR_RX_HALT(words) ((((words) / 4) & 0x0f) << 0)
218 #define SC16IS7XX_TCR_RX_RESUME(words) ((((words) / 4) & 0x0f) << 4)
219
220 /*
221 * TLR register bits
222 * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
223 * FIFO Control Register (FCR) are used for the transmit and receive FIFO
224 * trigger levels. Trigger levels from 4 characters to 60 characters are
225 * available with a granularity of four.
226 *
227 * When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the
228 * trigger level setting defined in FCR. If TLR has non-zero trigger level value
229 * the trigger level defined in FCR is discarded. This applies to both transmit
230 * FIFO and receive FIFO trigger level setting.
231 *
232 * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
233 * default state, that is, '00'.
234 */
235 #define SC16IS7XX_TLR_TX_TRIGGER(words) ((((words) / 4) & 0x0f) << 0)
236 #define SC16IS7XX_TLR_RX_TRIGGER(words) ((((words) / 4) & 0x0f) << 4)
237
238 /* IOControl register bits (Only 750/760) */
239 #define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */
240 #define SC16IS7XX_IOCONTROL_MODEM_A_BIT (1 << 1) /* Enable GPIO[7:4] as modem A pins */
241 #define SC16IS7XX_IOCONTROL_MODEM_B_BIT (1 << 2) /* Enable GPIO[3:0] as modem B pins */
242 #define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */
243
244 /* EFCR register bits */
245 #define SC16IS7XX_EFCR_9BIT_MODE_BIT (1 << 0) /* Enable 9-bit or Multidrop
246 * mode (RS485) */
247 #define SC16IS7XX_EFCR_RXDISABLE_BIT (1 << 1) /* Disable receiver */
248 #define SC16IS7XX_EFCR_TXDISABLE_BIT (1 << 2) /* Disable transmitter */
249 #define SC16IS7XX_EFCR_AUTO_RS485_BIT (1 << 4) /* Auto RS485 RTS direction */
250 #define SC16IS7XX_EFCR_RTS_INVERT_BIT (1 << 5) /* RTS output inversion */
251 #define SC16IS7XX_EFCR_IRDA_MODE_BIT (1 << 7) /* IrDA mode
252 * 0 = rate upto 115.2 kbit/s
253 * - Only 750/760
254 * 1 = rate upto 1.152 Mbit/s
255 * - Only 760
256 */
257
258 /* EFR register bits */
259 #define SC16IS7XX_EFR_AUTORTS_BIT (1 << 6) /* Auto RTS flow ctrl enable */
260 #define SC16IS7XX_EFR_AUTOCTS_BIT (1 << 7) /* Auto CTS flow ctrl enable */
261 #define SC16IS7XX_EFR_XOFF2_DETECT_BIT (1 << 5) /* Enable Xoff2 detection */
262 #define SC16IS7XX_EFR_ENABLE_BIT (1 << 4) /* Enable enhanced functions
263 * and writing to IER[7:4],
264 * FCR[5:4], MCR[7:5]
265 */
266 #define SC16IS7XX_EFR_SWFLOW3_BIT (1 << 3) /* SWFLOW bit 3 */
267 #define SC16IS7XX_EFR_SWFLOW2_BIT (1 << 2) /* SWFLOW bit 2
268 *
269 * SWFLOW bits 3 & 2 table:
270 * 00 -> no transmitter flow
271 * control
272 * 01 -> transmitter generates
273 * XON2 and XOFF2
274 * 10 -> transmitter generates
275 * XON1 and XOFF1
276 * 11 -> transmitter generates
277 * XON1, XON2, XOFF1 and
278 * XOFF2
279 */
280 #define SC16IS7XX_EFR_SWFLOW1_BIT (1 << 1) /* SWFLOW bit 2 */
281 #define SC16IS7XX_EFR_SWFLOW0_BIT (1 << 0) /* SWFLOW bit 3
282 *
283 * SWFLOW bits 3 & 2 table:
284 * 00 -> no received flow
285 * control
286 * 01 -> receiver compares
287 * XON2 and XOFF2
288 * 10 -> receiver compares
289 * XON1 and XOFF1
290 * 11 -> receiver compares
291 * XON1, XON2, XOFF1 and
292 * XOFF2
293 */
294 #define SC16IS7XX_EFR_FLOWCTRL_BITS (SC16IS7XX_EFR_AUTORTS_BIT | \
295 SC16IS7XX_EFR_AUTOCTS_BIT | \
296 SC16IS7XX_EFR_XOFF2_DETECT_BIT | \
297 SC16IS7XX_EFR_SWFLOW3_BIT | \
298 SC16IS7XX_EFR_SWFLOW2_BIT | \
299 SC16IS7XX_EFR_SWFLOW1_BIT | \
300 SC16IS7XX_EFR_SWFLOW0_BIT)
301
302
303 /* Misc definitions */
304 #define SC16IS7XX_SPI_READ_BIT BIT(7)
305 #define SC16IS7XX_FIFO_SIZE (64)
306 #define SC16IS7XX_GPIOS_PER_BANK 4
307
308 struct sc16is7xx_devtype {
309 char name[10];
310 int nr_gpio;
311 int nr_uart;
312 };
313
314 #define SC16IS7XX_RECONF_MD (1 << 0)
315 #define SC16IS7XX_RECONF_IER (1 << 1)
316 #define SC16IS7XX_RECONF_RS485 (1 << 2)
317
318 struct sc16is7xx_one_config {
319 unsigned int flags;
320 u8 ier_mask;
321 u8 ier_val;
322 };
323
324 struct sc16is7xx_one {
325 struct uart_port port;
326 struct regmap *regmap;
327 struct mutex efr_lock; /* EFR registers access */
328 struct kthread_work tx_work;
329 struct kthread_work reg_work;
330 struct kthread_delayed_work ms_work;
331 struct sc16is7xx_one_config config;
332 bool irda_mode;
333 unsigned int old_mctrl;
334 };
335
336 struct sc16is7xx_port {
337 const struct sc16is7xx_devtype *devtype;
338 struct clk *clk;
339 #ifdef CONFIG_GPIOLIB
340 struct gpio_chip gpio;
341 unsigned long gpio_valid_mask;
342 #endif
343 u8 mctrl_mask;
344 unsigned char buf[SC16IS7XX_FIFO_SIZE];
345 struct kthread_worker kworker;
346 struct task_struct *kworker_task;
347 struct sc16is7xx_one p[];
348 };
349
350 static unsigned long sc16is7xx_lines;
351
352 static struct uart_driver sc16is7xx_uart = {
353 .owner = THIS_MODULE,
354 .dev_name = "ttySC",
355 .nr = SC16IS7XX_MAX_DEVS,
356 };
357
358 static void sc16is7xx_ier_set(struct uart_port *port, u8 bit);
359 static void sc16is7xx_stop_tx(struct uart_port *port);
360
361 #define to_sc16is7xx_port(p,e) ((container_of((p), struct sc16is7xx_port, e)))
362 #define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e)))
363
sc16is7xx_port_read(struct uart_port * port,u8 reg)364 static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
365 {
366 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
367 unsigned int val = 0;
368
369 regmap_read(one->regmap, reg, &val);
370
371 return val;
372 }
373
sc16is7xx_port_write(struct uart_port * port,u8 reg,u8 val)374 static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
375 {
376 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
377
378 regmap_write(one->regmap, reg, val);
379 }
380
sc16is7xx_fifo_read(struct uart_port * port,unsigned int rxlen)381 static void sc16is7xx_fifo_read(struct uart_port *port, unsigned int rxlen)
382 {
383 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
384 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
385
386 regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, s->buf, rxlen);
387 }
388
sc16is7xx_fifo_write(struct uart_port * port,u8 to_send)389 static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
390 {
391 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
392 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
393
394 /*
395 * Don't send zero-length data, at least on SPI it confuses the chip
396 * delivering wrong TXLVL data.
397 */
398 if (unlikely(!to_send))
399 return;
400
401 regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, s->buf, to_send);
402 }
403
sc16is7xx_port_update(struct uart_port * port,u8 reg,u8 mask,u8 val)404 static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
405 u8 mask, u8 val)
406 {
407 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
408
409 regmap_update_bits(one->regmap, reg, mask, val);
410 }
411
sc16is7xx_power(struct uart_port * port,int on)412 static void sc16is7xx_power(struct uart_port *port, int on)
413 {
414 sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
415 SC16IS7XX_IER_SLEEP_BIT,
416 on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
417 }
418
419 static const struct sc16is7xx_devtype sc16is74x_devtype = {
420 .name = "SC16IS74X",
421 .nr_gpio = 0,
422 .nr_uart = 1,
423 };
424
425 static const struct sc16is7xx_devtype sc16is750_devtype = {
426 .name = "SC16IS750",
427 .nr_gpio = 8,
428 .nr_uart = 1,
429 };
430
431 static const struct sc16is7xx_devtype sc16is752_devtype = {
432 .name = "SC16IS752",
433 .nr_gpio = 8,
434 .nr_uart = 2,
435 };
436
437 static const struct sc16is7xx_devtype sc16is760_devtype = {
438 .name = "SC16IS760",
439 .nr_gpio = 8,
440 .nr_uart = 1,
441 };
442
443 static const struct sc16is7xx_devtype sc16is762_devtype = {
444 .name = "SC16IS762",
445 .nr_gpio = 8,
446 .nr_uart = 2,
447 };
448
sc16is7xx_regmap_volatile(struct device * dev,unsigned int reg)449 static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
450 {
451 switch (reg) {
452 case SC16IS7XX_RHR_REG:
453 case SC16IS7XX_IIR_REG:
454 case SC16IS7XX_LSR_REG:
455 case SC16IS7XX_MSR_REG:
456 case SC16IS7XX_TXLVL_REG:
457 case SC16IS7XX_RXLVL_REG:
458 case SC16IS7XX_IOSTATE_REG:
459 case SC16IS7XX_IOCONTROL_REG:
460 return true;
461 default:
462 break;
463 }
464
465 return false;
466 }
467
sc16is7xx_regmap_precious(struct device * dev,unsigned int reg)468 static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
469 {
470 switch (reg) {
471 case SC16IS7XX_RHR_REG:
472 return true;
473 default:
474 break;
475 }
476
477 return false;
478 }
479
sc16is7xx_regmap_noinc(struct device * dev,unsigned int reg)480 static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
481 {
482 return reg == SC16IS7XX_RHR_REG;
483 }
484
485 /*
486 * Configure programmable baud rate generator (divisor) according to the
487 * desired baud rate.
488 *
489 * From the datasheet, the divisor is computed according to:
490 *
491 * XTAL1 input frequency
492 * -----------------------
493 * prescaler
494 * divisor = ---------------------------
495 * baud-rate x sampling-rate
496 */
sc16is7xx_set_baud(struct uart_port * port,int baud)497 static int sc16is7xx_set_baud(struct uart_port *port, int baud)
498 {
499 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
500 u8 lcr;
501 unsigned int prescaler = 1;
502 unsigned long clk = port->uartclk, div = clk / 16 / baud;
503
504 if (div >= BIT(16)) {
505 prescaler = 4;
506 div /= prescaler;
507 }
508
509 /* In an amazing feat of design, the Enhanced Features Register shares
510 * the address of the Interrupt Identification Register, and is
511 * switched in by writing a magic value (0xbf) to the Line Control
512 * Register. Any interrupt firing during this time will see the EFR
513 * where it expects the IIR to be, leading to "Unexpected interrupt"
514 * messages.
515 *
516 * Prevent this possibility by claiming a mutex while accessing the
517 * EFR, and claiming the same mutex from within the interrupt handler.
518 * This is similar to disabling the interrupt, but that doesn't work
519 * because the bulk of the interrupt processing is run as a workqueue
520 * job in thread context.
521 */
522 mutex_lock(&one->efr_lock);
523
524 lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
525
526 /* Open the LCR divisors for configuration */
527 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
528 SC16IS7XX_LCR_CONF_MODE_B);
529
530 /* Enable enhanced features */
531 regcache_cache_bypass(one->regmap, true);
532 sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
533 SC16IS7XX_EFR_ENABLE_BIT,
534 SC16IS7XX_EFR_ENABLE_BIT);
535
536 regcache_cache_bypass(one->regmap, false);
537
538 /* Put LCR back to the normal mode */
539 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
540
541 mutex_unlock(&one->efr_lock);
542
543 /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */
544 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
545 SC16IS7XX_MCR_CLKSEL_BIT,
546 prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT);
547
548 mutex_lock(&one->efr_lock);
549
550 /* Open the LCR divisors for configuration */
551 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
552 SC16IS7XX_LCR_CONF_MODE_A);
553
554 /* Write the new divisor */
555 regcache_cache_bypass(one->regmap, true);
556 sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
557 sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
558 regcache_cache_bypass(one->regmap, false);
559
560 /* Put LCR back to the normal mode */
561 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
562
563 mutex_unlock(&one->efr_lock);
564
565 return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div);
566 }
567
sc16is7xx_handle_rx(struct uart_port * port,unsigned int rxlen,unsigned int iir)568 static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
569 unsigned int iir)
570 {
571 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
572 unsigned int lsr = 0, bytes_read, i;
573 bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
574 u8 ch, flag;
575
576 if (unlikely(rxlen >= sizeof(s->buf))) {
577 dev_warn_ratelimited(port->dev,
578 "ttySC%i: Possible RX FIFO overrun: %d\n",
579 port->line, rxlen);
580 port->icount.buf_overrun++;
581 /* Ensure sanity of RX level */
582 rxlen = sizeof(s->buf);
583 }
584
585 while (rxlen) {
586 /* Only read lsr if there are possible errors in FIFO */
587 if (read_lsr) {
588 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
589 if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
590 read_lsr = false; /* No errors left in FIFO */
591 } else
592 lsr = 0;
593
594 if (read_lsr) {
595 s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
596 bytes_read = 1;
597 } else {
598 sc16is7xx_fifo_read(port, rxlen);
599 bytes_read = rxlen;
600 }
601
602 lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
603
604 port->icount.rx++;
605 flag = TTY_NORMAL;
606
607 if (unlikely(lsr)) {
608 if (lsr & SC16IS7XX_LSR_BI_BIT) {
609 port->icount.brk++;
610 if (uart_handle_break(port))
611 continue;
612 } else if (lsr & SC16IS7XX_LSR_PE_BIT)
613 port->icount.parity++;
614 else if (lsr & SC16IS7XX_LSR_FE_BIT)
615 port->icount.frame++;
616 else if (lsr & SC16IS7XX_LSR_OE_BIT)
617 port->icount.overrun++;
618
619 lsr &= port->read_status_mask;
620 if (lsr & SC16IS7XX_LSR_BI_BIT)
621 flag = TTY_BREAK;
622 else if (lsr & SC16IS7XX_LSR_PE_BIT)
623 flag = TTY_PARITY;
624 else if (lsr & SC16IS7XX_LSR_FE_BIT)
625 flag = TTY_FRAME;
626 else if (lsr & SC16IS7XX_LSR_OE_BIT)
627 flag = TTY_OVERRUN;
628 }
629
630 for (i = 0; i < bytes_read; ++i) {
631 ch = s->buf[i];
632 if (uart_handle_sysrq_char(port, ch))
633 continue;
634
635 if (lsr & port->ignore_status_mask)
636 continue;
637
638 uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
639 flag);
640 }
641 rxlen -= bytes_read;
642 }
643
644 tty_flip_buffer_push(&port->state->port);
645 }
646
sc16is7xx_handle_tx(struct uart_port * port)647 static void sc16is7xx_handle_tx(struct uart_port *port)
648 {
649 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
650 struct circ_buf *xmit = &port->state->xmit;
651 unsigned int txlen, to_send, i;
652 unsigned long flags;
653
654 if (unlikely(port->x_char)) {
655 sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
656 port->icount.tx++;
657 port->x_char = 0;
658 return;
659 }
660
661 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
662 uart_port_lock_irqsave(port, &flags);
663 sc16is7xx_stop_tx(port);
664 uart_port_unlock_irqrestore(port, flags);
665 return;
666 }
667
668 /* Get length of data pending in circular buffer */
669 to_send = uart_circ_chars_pending(xmit);
670 if (likely(to_send)) {
671 /* Limit to size of TX FIFO */
672 txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
673 if (txlen > SC16IS7XX_FIFO_SIZE) {
674 dev_err_ratelimited(port->dev,
675 "chip reports %d free bytes in TX fifo, but it only has %d",
676 txlen, SC16IS7XX_FIFO_SIZE);
677 txlen = 0;
678 }
679 to_send = (to_send > txlen) ? txlen : to_send;
680
681 /* Convert to linear buffer */
682 for (i = 0; i < to_send; ++i) {
683 s->buf[i] = xmit->buf[xmit->tail];
684 uart_xmit_advance(port, 1);
685 }
686
687 sc16is7xx_fifo_write(port, to_send);
688 }
689
690 uart_port_lock_irqsave(port, &flags);
691 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
692 uart_write_wakeup(port);
693
694 if (uart_circ_empty(xmit))
695 sc16is7xx_stop_tx(port);
696 else
697 sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
698 uart_port_unlock_irqrestore(port, flags);
699 }
700
sc16is7xx_get_hwmctrl(struct uart_port * port)701 static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
702 {
703 u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
704 unsigned int mctrl = 0;
705
706 mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
707 mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0;
708 mctrl |= (msr & SC16IS7XX_MSR_CD_BIT) ? TIOCM_CAR : 0;
709 mctrl |= (msr & SC16IS7XX_MSR_RI_BIT) ? TIOCM_RNG : 0;
710 return mctrl;
711 }
712
sc16is7xx_update_mlines(struct sc16is7xx_one * one)713 static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
714 {
715 struct uart_port *port = &one->port;
716 unsigned long flags;
717 unsigned int status, changed;
718
719 lockdep_assert_held_once(&one->efr_lock);
720
721 status = sc16is7xx_get_hwmctrl(port);
722 changed = status ^ one->old_mctrl;
723
724 if (changed == 0)
725 return;
726
727 one->old_mctrl = status;
728
729 uart_port_lock_irqsave(port, &flags);
730 if ((changed & TIOCM_RNG) && (status & TIOCM_RNG))
731 port->icount.rng++;
732 if (changed & TIOCM_DSR)
733 port->icount.dsr++;
734 if (changed & TIOCM_CAR)
735 uart_handle_dcd_change(port, status & TIOCM_CAR);
736 if (changed & TIOCM_CTS)
737 uart_handle_cts_change(port, status & TIOCM_CTS);
738
739 wake_up_interruptible(&port->state->port.delta_msr_wait);
740 uart_port_unlock_irqrestore(port, flags);
741 }
742
sc16is7xx_port_irq(struct sc16is7xx_port * s,int portno)743 static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
744 {
745 bool rc = true;
746 unsigned int iir, rxlen;
747 struct uart_port *port = &s->p[portno].port;
748 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
749
750 mutex_lock(&one->efr_lock);
751
752 iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
753 if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
754 rc = false;
755 goto out_port_irq;
756 }
757
758 iir &= SC16IS7XX_IIR_ID_MASK;
759
760 switch (iir) {
761 case SC16IS7XX_IIR_RDI_SRC:
762 case SC16IS7XX_IIR_RLSE_SRC:
763 case SC16IS7XX_IIR_RTOI_SRC:
764 case SC16IS7XX_IIR_XOFFI_SRC:
765 rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
766
767 /*
768 * There is a silicon bug that makes the chip report a
769 * time-out interrupt but no data in the FIFO. This is
770 * described in errata section 18.1.4.
771 *
772 * When this happens, read one byte from the FIFO to
773 * clear the interrupt.
774 */
775 if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen)
776 rxlen = 1;
777
778 if (rxlen)
779 sc16is7xx_handle_rx(port, rxlen, iir);
780 break;
781 /* CTSRTS interrupt comes only when CTS goes inactive */
782 case SC16IS7XX_IIR_CTSRTS_SRC:
783 case SC16IS7XX_IIR_MSI_SRC:
784 sc16is7xx_update_mlines(one);
785 break;
786 case SC16IS7XX_IIR_THRI_SRC:
787 sc16is7xx_handle_tx(port);
788 break;
789 default:
790 dev_err_ratelimited(port->dev,
791 "ttySC%i: Unexpected interrupt: %x",
792 port->line, iir);
793 break;
794 }
795
796 out_port_irq:
797 mutex_unlock(&one->efr_lock);
798
799 return rc;
800 }
801
sc16is7xx_irq(int irq,void * dev_id)802 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
803 {
804 bool keep_polling;
805
806 struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
807
808 do {
809 int i;
810
811 keep_polling = false;
812
813 for (i = 0; i < s->devtype->nr_uart; ++i)
814 keep_polling |= sc16is7xx_port_irq(s, i);
815 } while (keep_polling);
816
817 return IRQ_HANDLED;
818 }
819
sc16is7xx_tx_proc(struct kthread_work * ws)820 static void sc16is7xx_tx_proc(struct kthread_work *ws)
821 {
822 struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
823 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
824
825 if ((port->rs485.flags & SER_RS485_ENABLED) &&
826 (port->rs485.delay_rts_before_send > 0))
827 msleep(port->rs485.delay_rts_before_send);
828
829 mutex_lock(&one->efr_lock);
830 sc16is7xx_handle_tx(port);
831 mutex_unlock(&one->efr_lock);
832 }
833
sc16is7xx_reconf_rs485(struct uart_port * port)834 static void sc16is7xx_reconf_rs485(struct uart_port *port)
835 {
836 const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
837 SC16IS7XX_EFCR_RTS_INVERT_BIT;
838 u32 efcr = 0;
839 struct serial_rs485 *rs485 = &port->rs485;
840 unsigned long irqflags;
841
842 uart_port_lock_irqsave(port, &irqflags);
843 if (rs485->flags & SER_RS485_ENABLED) {
844 efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT;
845
846 if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
847 efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
848 }
849 uart_port_unlock_irqrestore(port, irqflags);
850
851 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
852 }
853
sc16is7xx_reg_proc(struct kthread_work * ws)854 static void sc16is7xx_reg_proc(struct kthread_work *ws)
855 {
856 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
857 struct sc16is7xx_one_config config;
858 unsigned long irqflags;
859
860 uart_port_lock_irqsave(&one->port, &irqflags);
861 config = one->config;
862 memset(&one->config, 0, sizeof(one->config));
863 uart_port_unlock_irqrestore(&one->port, irqflags);
864
865 if (config.flags & SC16IS7XX_RECONF_MD) {
866 u8 mcr = 0;
867
868 /* Device ignores RTS setting when hardware flow is enabled */
869 if (one->port.mctrl & TIOCM_RTS)
870 mcr |= SC16IS7XX_MCR_RTS_BIT;
871
872 if (one->port.mctrl & TIOCM_DTR)
873 mcr |= SC16IS7XX_MCR_DTR_BIT;
874
875 if (one->port.mctrl & TIOCM_LOOP)
876 mcr |= SC16IS7XX_MCR_LOOP_BIT;
877 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
878 SC16IS7XX_MCR_RTS_BIT |
879 SC16IS7XX_MCR_DTR_BIT |
880 SC16IS7XX_MCR_LOOP_BIT,
881 mcr);
882 }
883
884 if (config.flags & SC16IS7XX_RECONF_IER)
885 sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
886 config.ier_mask, config.ier_val);
887
888 if (config.flags & SC16IS7XX_RECONF_RS485)
889 sc16is7xx_reconf_rs485(&one->port);
890 }
891
sc16is7xx_ier_clear(struct uart_port * port,u8 bit)892 static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
893 {
894 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
895 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
896
897 lockdep_assert_held_once(&port->lock);
898
899 one->config.flags |= SC16IS7XX_RECONF_IER;
900 one->config.ier_mask |= bit;
901 one->config.ier_val &= ~bit;
902 kthread_queue_work(&s->kworker, &one->reg_work);
903 }
904
sc16is7xx_ier_set(struct uart_port * port,u8 bit)905 static void sc16is7xx_ier_set(struct uart_port *port, u8 bit)
906 {
907 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
908 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
909
910 lockdep_assert_held_once(&port->lock);
911
912 one->config.flags |= SC16IS7XX_RECONF_IER;
913 one->config.ier_mask |= bit;
914 one->config.ier_val |= bit;
915 kthread_queue_work(&s->kworker, &one->reg_work);
916 }
917
sc16is7xx_stop_tx(struct uart_port * port)918 static void sc16is7xx_stop_tx(struct uart_port *port)
919 {
920 sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
921 }
922
sc16is7xx_stop_rx(struct uart_port * port)923 static void sc16is7xx_stop_rx(struct uart_port *port)
924 {
925 sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
926 }
927
sc16is7xx_ms_proc(struct kthread_work * ws)928 static void sc16is7xx_ms_proc(struct kthread_work *ws)
929 {
930 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work);
931 struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
932
933 if (one->port.state) {
934 mutex_lock(&one->efr_lock);
935 sc16is7xx_update_mlines(one);
936 mutex_unlock(&one->efr_lock);
937
938 kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
939 }
940 }
941
sc16is7xx_enable_ms(struct uart_port * port)942 static void sc16is7xx_enable_ms(struct uart_port *port)
943 {
944 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
945 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
946
947 lockdep_assert_held_once(&port->lock);
948
949 kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0);
950 }
951
sc16is7xx_start_tx(struct uart_port * port)952 static void sc16is7xx_start_tx(struct uart_port *port)
953 {
954 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
955 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
956
957 kthread_queue_work(&s->kworker, &one->tx_work);
958 }
959
sc16is7xx_throttle(struct uart_port * port)960 static void sc16is7xx_throttle(struct uart_port *port)
961 {
962 unsigned long flags;
963
964 /*
965 * Hardware flow control is enabled and thus the device ignores RTS
966 * value set in MCR register. Stop reading data from RX FIFO so the
967 * AutoRTS feature will de-activate RTS output.
968 */
969 uart_port_lock_irqsave(port, &flags);
970 sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
971 uart_port_unlock_irqrestore(port, flags);
972 }
973
sc16is7xx_unthrottle(struct uart_port * port)974 static void sc16is7xx_unthrottle(struct uart_port *port)
975 {
976 unsigned long flags;
977
978 uart_port_lock_irqsave(port, &flags);
979 sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT);
980 uart_port_unlock_irqrestore(port, flags);
981 }
982
sc16is7xx_tx_empty(struct uart_port * port)983 static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
984 {
985 unsigned int lsr;
986
987 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
988
989 return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
990 }
991
sc16is7xx_get_mctrl(struct uart_port * port)992 static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
993 {
994 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
995
996 /* Called with port lock taken so we can only return cached value */
997 return one->old_mctrl;
998 }
999
sc16is7xx_set_mctrl(struct uart_port * port,unsigned int mctrl)1000 static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
1001 {
1002 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1003 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1004
1005 one->config.flags |= SC16IS7XX_RECONF_MD;
1006 kthread_queue_work(&s->kworker, &one->reg_work);
1007 }
1008
sc16is7xx_break_ctl(struct uart_port * port,int break_state)1009 static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
1010 {
1011 sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
1012 SC16IS7XX_LCR_TXBREAK_BIT,
1013 break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
1014 }
1015
sc16is7xx_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)1016 static void sc16is7xx_set_termios(struct uart_port *port,
1017 struct ktermios *termios,
1018 const struct ktermios *old)
1019 {
1020 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1021 unsigned int lcr, flow = 0;
1022 int baud;
1023 unsigned long flags;
1024
1025 kthread_cancel_delayed_work_sync(&one->ms_work);
1026
1027 /* Mask termios capabilities we don't support */
1028 termios->c_cflag &= ~CMSPAR;
1029
1030 /* Word size */
1031 switch (termios->c_cflag & CSIZE) {
1032 case CS5:
1033 lcr = SC16IS7XX_LCR_WORD_LEN_5;
1034 break;
1035 case CS6:
1036 lcr = SC16IS7XX_LCR_WORD_LEN_6;
1037 break;
1038 case CS7:
1039 lcr = SC16IS7XX_LCR_WORD_LEN_7;
1040 break;
1041 case CS8:
1042 lcr = SC16IS7XX_LCR_WORD_LEN_8;
1043 break;
1044 default:
1045 lcr = SC16IS7XX_LCR_WORD_LEN_8;
1046 termios->c_cflag &= ~CSIZE;
1047 termios->c_cflag |= CS8;
1048 break;
1049 }
1050
1051 /* Parity */
1052 if (termios->c_cflag & PARENB) {
1053 lcr |= SC16IS7XX_LCR_PARITY_BIT;
1054 if (!(termios->c_cflag & PARODD))
1055 lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
1056 }
1057
1058 /* Stop bits */
1059 if (termios->c_cflag & CSTOPB)
1060 lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
1061
1062 /* Set read status mask */
1063 port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
1064 if (termios->c_iflag & INPCK)
1065 port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
1066 SC16IS7XX_LSR_FE_BIT;
1067 if (termios->c_iflag & (BRKINT | PARMRK))
1068 port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
1069
1070 /* Set status ignore mask */
1071 port->ignore_status_mask = 0;
1072 if (termios->c_iflag & IGNBRK)
1073 port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
1074 if (!(termios->c_cflag & CREAD))
1075 port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
1076
1077 /* As above, claim the mutex while accessing the EFR. */
1078 mutex_lock(&one->efr_lock);
1079
1080 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
1081 SC16IS7XX_LCR_CONF_MODE_B);
1082
1083 /* Configure flow control */
1084 regcache_cache_bypass(one->regmap, true);
1085 sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
1086 sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
1087
1088 port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
1089 if (termios->c_cflag & CRTSCTS) {
1090 flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
1091 SC16IS7XX_EFR_AUTORTS_BIT;
1092 port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1093 }
1094 if (termios->c_iflag & IXON)
1095 flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
1096 if (termios->c_iflag & IXOFF)
1097 flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
1098
1099 sc16is7xx_port_update(port,
1100 SC16IS7XX_EFR_REG,
1101 SC16IS7XX_EFR_FLOWCTRL_BITS,
1102 flow);
1103 regcache_cache_bypass(one->regmap, false);
1104
1105 /* Update LCR register */
1106 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
1107
1108 mutex_unlock(&one->efr_lock);
1109
1110 /* Get baud rate generator configuration */
1111 baud = uart_get_baud_rate(port, termios, old,
1112 port->uartclk / 16 / 4 / 0xffff,
1113 port->uartclk / 16);
1114
1115 /* Setup baudrate generator */
1116 baud = sc16is7xx_set_baud(port, baud);
1117
1118 uart_port_lock_irqsave(port, &flags);
1119
1120 /* Update timeout according to new baud rate */
1121 uart_update_timeout(port, termios->c_cflag, baud);
1122
1123 if (UART_ENABLE_MS(port, termios->c_cflag))
1124 sc16is7xx_enable_ms(port);
1125
1126 uart_port_unlock_irqrestore(port, flags);
1127 }
1128
sc16is7xx_config_rs485(struct uart_port * port,struct ktermios * termios,struct serial_rs485 * rs485)1129 static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios,
1130 struct serial_rs485 *rs485)
1131 {
1132 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1133 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1134
1135 if (rs485->flags & SER_RS485_ENABLED) {
1136 /*
1137 * RTS signal is handled by HW, it's timing can't be influenced.
1138 * However, it's sometimes useful to delay TX even without RTS
1139 * control therefore we try to handle .delay_rts_before_send.
1140 */
1141 if (rs485->delay_rts_after_send)
1142 return -EINVAL;
1143 }
1144
1145 one->config.flags |= SC16IS7XX_RECONF_RS485;
1146 kthread_queue_work(&s->kworker, &one->reg_work);
1147
1148 return 0;
1149 }
1150
sc16is7xx_startup(struct uart_port * port)1151 static int sc16is7xx_startup(struct uart_port *port)
1152 {
1153 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1154 unsigned int val;
1155 unsigned long flags;
1156
1157 sc16is7xx_power(port, 1);
1158
1159 /* Reset FIFOs*/
1160 val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
1161 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
1162 udelay(5);
1163 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
1164 SC16IS7XX_FCR_FIFO_BIT);
1165
1166 /* Enable EFR */
1167 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
1168 SC16IS7XX_LCR_CONF_MODE_B);
1169
1170 regcache_cache_bypass(one->regmap, true);
1171
1172 /* Enable write access to enhanced features and internal clock div */
1173 sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1174 SC16IS7XX_EFR_ENABLE_BIT,
1175 SC16IS7XX_EFR_ENABLE_BIT);
1176
1177 /* Enable TCR/TLR */
1178 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1179 SC16IS7XX_MCR_TCRTLR_BIT,
1180 SC16IS7XX_MCR_TCRTLR_BIT);
1181
1182 /* Configure flow control levels */
1183 /* Flow control halt level 48, resume level 24 */
1184 sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
1185 SC16IS7XX_TCR_RX_RESUME(24) |
1186 SC16IS7XX_TCR_RX_HALT(48));
1187
1188 regcache_cache_bypass(one->regmap, false);
1189
1190 /* Now, initialize the UART */
1191 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
1192
1193 /* Enable IrDA mode if requested in DT */
1194 /* This bit must be written with LCR[7] = 0 */
1195 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1196 SC16IS7XX_MCR_IRDA_BIT,
1197 one->irda_mode ?
1198 SC16IS7XX_MCR_IRDA_BIT : 0);
1199
1200 /* Enable the Rx and Tx FIFO */
1201 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1202 SC16IS7XX_EFCR_RXDISABLE_BIT |
1203 SC16IS7XX_EFCR_TXDISABLE_BIT,
1204 0);
1205
1206 /* Enable RX, CTS change and modem lines interrupts */
1207 val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT |
1208 SC16IS7XX_IER_MSI_BIT;
1209 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1210
1211 /* Enable modem status polling */
1212 uart_port_lock_irqsave(port, &flags);
1213 sc16is7xx_enable_ms(port);
1214 uart_port_unlock_irqrestore(port, flags);
1215
1216 return 0;
1217 }
1218
sc16is7xx_shutdown(struct uart_port * port)1219 static void sc16is7xx_shutdown(struct uart_port *port)
1220 {
1221 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1222 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1223
1224 kthread_cancel_delayed_work_sync(&one->ms_work);
1225
1226 /* Disable all interrupts */
1227 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1228 /* Disable TX/RX */
1229 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1230 SC16IS7XX_EFCR_RXDISABLE_BIT |
1231 SC16IS7XX_EFCR_TXDISABLE_BIT,
1232 SC16IS7XX_EFCR_RXDISABLE_BIT |
1233 SC16IS7XX_EFCR_TXDISABLE_BIT);
1234
1235 sc16is7xx_power(port, 0);
1236
1237 kthread_flush_worker(&s->kworker);
1238 }
1239
sc16is7xx_type(struct uart_port * port)1240 static const char *sc16is7xx_type(struct uart_port *port)
1241 {
1242 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1243
1244 return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1245 }
1246
sc16is7xx_request_port(struct uart_port * port)1247 static int sc16is7xx_request_port(struct uart_port *port)
1248 {
1249 /* Do nothing */
1250 return 0;
1251 }
1252
sc16is7xx_config_port(struct uart_port * port,int flags)1253 static void sc16is7xx_config_port(struct uart_port *port, int flags)
1254 {
1255 if (flags & UART_CONFIG_TYPE)
1256 port->type = PORT_SC16IS7XX;
1257 }
1258
sc16is7xx_verify_port(struct uart_port * port,struct serial_struct * s)1259 static int sc16is7xx_verify_port(struct uart_port *port,
1260 struct serial_struct *s)
1261 {
1262 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1263 return -EINVAL;
1264 if (s->irq != port->irq)
1265 return -EINVAL;
1266
1267 return 0;
1268 }
1269
sc16is7xx_pm(struct uart_port * port,unsigned int state,unsigned int oldstate)1270 static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1271 unsigned int oldstate)
1272 {
1273 sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1274 }
1275
sc16is7xx_null_void(struct uart_port * port)1276 static void sc16is7xx_null_void(struct uart_port *port)
1277 {
1278 /* Do nothing */
1279 }
1280
1281 static const struct uart_ops sc16is7xx_ops = {
1282 .tx_empty = sc16is7xx_tx_empty,
1283 .set_mctrl = sc16is7xx_set_mctrl,
1284 .get_mctrl = sc16is7xx_get_mctrl,
1285 .stop_tx = sc16is7xx_stop_tx,
1286 .start_tx = sc16is7xx_start_tx,
1287 .throttle = sc16is7xx_throttle,
1288 .unthrottle = sc16is7xx_unthrottle,
1289 .stop_rx = sc16is7xx_stop_rx,
1290 .enable_ms = sc16is7xx_enable_ms,
1291 .break_ctl = sc16is7xx_break_ctl,
1292 .startup = sc16is7xx_startup,
1293 .shutdown = sc16is7xx_shutdown,
1294 .set_termios = sc16is7xx_set_termios,
1295 .type = sc16is7xx_type,
1296 .request_port = sc16is7xx_request_port,
1297 .release_port = sc16is7xx_null_void,
1298 .config_port = sc16is7xx_config_port,
1299 .verify_port = sc16is7xx_verify_port,
1300 .pm = sc16is7xx_pm,
1301 };
1302
1303 #ifdef CONFIG_GPIOLIB
sc16is7xx_gpio_get(struct gpio_chip * chip,unsigned offset)1304 static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1305 {
1306 unsigned int val;
1307 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1308 struct uart_port *port = &s->p[0].port;
1309
1310 val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1311
1312 return !!(val & BIT(offset));
1313 }
1314
sc16is7xx_gpio_set(struct gpio_chip * chip,unsigned offset,int val)1315 static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1316 {
1317 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1318 struct uart_port *port = &s->p[0].port;
1319
1320 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1321 val ? BIT(offset) : 0);
1322 }
1323
sc16is7xx_gpio_direction_input(struct gpio_chip * chip,unsigned offset)1324 static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1325 unsigned offset)
1326 {
1327 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1328 struct uart_port *port = &s->p[0].port;
1329
1330 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1331
1332 return 0;
1333 }
1334
sc16is7xx_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int val)1335 static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1336 unsigned offset, int val)
1337 {
1338 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1339 struct uart_port *port = &s->p[0].port;
1340 u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1341
1342 if (val)
1343 state |= BIT(offset);
1344 else
1345 state &= ~BIT(offset);
1346
1347 /*
1348 * If we write IOSTATE first, and then IODIR, the output value is not
1349 * transferred to the corresponding I/O pin.
1350 * The datasheet states that each register bit will be transferred to
1351 * the corresponding I/O pin programmed as output when writing to
1352 * IOSTATE. Therefore, configure direction first with IODIR, and then
1353 * set value after with IOSTATE.
1354 */
1355 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1356 BIT(offset));
1357 sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
1358
1359 return 0;
1360 }
1361
sc16is7xx_gpio_init_valid_mask(struct gpio_chip * chip,unsigned long * valid_mask,unsigned int ngpios)1362 static int sc16is7xx_gpio_init_valid_mask(struct gpio_chip *chip,
1363 unsigned long *valid_mask,
1364 unsigned int ngpios)
1365 {
1366 struct sc16is7xx_port *s = gpiochip_get_data(chip);
1367
1368 *valid_mask = s->gpio_valid_mask;
1369
1370 return 0;
1371 }
1372
sc16is7xx_setup_gpio_chip(struct sc16is7xx_port * s)1373 static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s)
1374 {
1375 struct device *dev = s->p[0].port.dev;
1376
1377 if (!s->devtype->nr_gpio)
1378 return 0;
1379
1380 switch (s->mctrl_mask) {
1381 case 0:
1382 s->gpio_valid_mask = GENMASK(7, 0);
1383 break;
1384 case SC16IS7XX_IOCONTROL_MODEM_A_BIT:
1385 s->gpio_valid_mask = GENMASK(3, 0);
1386 break;
1387 case SC16IS7XX_IOCONTROL_MODEM_B_BIT:
1388 s->gpio_valid_mask = GENMASK(7, 4);
1389 break;
1390 default:
1391 break;
1392 }
1393
1394 if (s->gpio_valid_mask == 0)
1395 return 0;
1396
1397 s->gpio.owner = THIS_MODULE;
1398 s->gpio.parent = dev;
1399 s->gpio.label = dev_name(dev);
1400 s->gpio.init_valid_mask = sc16is7xx_gpio_init_valid_mask;
1401 s->gpio.direction_input = sc16is7xx_gpio_direction_input;
1402 s->gpio.get = sc16is7xx_gpio_get;
1403 s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1404 s->gpio.set = sc16is7xx_gpio_set;
1405 s->gpio.base = -1;
1406 s->gpio.ngpio = s->devtype->nr_gpio;
1407 s->gpio.can_sleep = 1;
1408
1409 return gpiochip_add_data(&s->gpio, s);
1410 }
1411 #endif
1412
sc16is7xx_setup_irda_ports(struct sc16is7xx_port * s)1413 static void sc16is7xx_setup_irda_ports(struct sc16is7xx_port *s)
1414 {
1415 int i;
1416 int ret;
1417 int count;
1418 u32 irda_port[2];
1419 struct device *dev = s->p[0].port.dev;
1420
1421 count = device_property_count_u32(dev, "irda-mode-ports");
1422 if (count < 0 || count > ARRAY_SIZE(irda_port))
1423 return;
1424
1425 ret = device_property_read_u32_array(dev, "irda-mode-ports",
1426 irda_port, count);
1427 if (ret)
1428 return;
1429
1430 for (i = 0; i < count; i++) {
1431 if (irda_port[i] < s->devtype->nr_uart)
1432 s->p[irda_port[i]].irda_mode = true;
1433 }
1434 }
1435
1436 /*
1437 * Configure ports designated to operate as modem control lines.
1438 */
sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port * s,struct regmap * regmap)1439 static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
1440 struct regmap *regmap)
1441 {
1442 int i;
1443 int ret;
1444 int count;
1445 u32 mctrl_port[2];
1446 struct device *dev = s->p[0].port.dev;
1447
1448 count = device_property_count_u32(dev, "nxp,modem-control-line-ports");
1449 if (count < 0 || count > ARRAY_SIZE(mctrl_port))
1450 return 0;
1451
1452 ret = device_property_read_u32_array(dev, "nxp,modem-control-line-ports",
1453 mctrl_port, count);
1454 if (ret)
1455 return ret;
1456
1457 s->mctrl_mask = 0;
1458
1459 for (i = 0; i < count; i++) {
1460 /* Use GPIO lines as modem control lines */
1461 if (mctrl_port[i] == 0)
1462 s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
1463 else if (mctrl_port[i] == 1)
1464 s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
1465 }
1466
1467 if (s->mctrl_mask)
1468 regmap_update_bits(
1469 regmap,
1470 SC16IS7XX_IOCONTROL_REG,
1471 SC16IS7XX_IOCONTROL_MODEM_A_BIT |
1472 SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask);
1473
1474 return 0;
1475 }
1476
1477 static const struct serial_rs485 sc16is7xx_rs485_supported = {
1478 .flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
1479 .delay_rts_before_send = 1,
1480 .delay_rts_after_send = 1, /* Not supported but keep returning -EINVAL */
1481 };
1482
sc16is7xx_probe(struct device * dev,const struct sc16is7xx_devtype * devtype,struct regmap * regmaps[],int irq)1483 static int sc16is7xx_probe(struct device *dev,
1484 const struct sc16is7xx_devtype *devtype,
1485 struct regmap *regmaps[], int irq)
1486 {
1487 unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
1488 unsigned int val;
1489 u32 uartclk = 0;
1490 int i, ret;
1491 struct sc16is7xx_port *s;
1492
1493 for (i = 0; i < devtype->nr_uart; i++)
1494 if (IS_ERR(regmaps[i]))
1495 return PTR_ERR(regmaps[i]);
1496
1497 /*
1498 * This device does not have an identification register that would
1499 * tell us if we are really connected to the correct device.
1500 * The best we can do is to check if communication is at all possible.
1501 *
1502 * Note: regmap[0] is used in the probe function to access registers
1503 * common to all channels/ports, as it is guaranteed to be present on
1504 * all variants.
1505 */
1506 ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val);
1507 if (ret < 0)
1508 return -EPROBE_DEFER;
1509
1510 /* Alloc port structure */
1511 s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
1512 if (!s) {
1513 dev_err(dev, "Error allocating port structure\n");
1514 return -ENOMEM;
1515 }
1516
1517 /* Always ask for fixed clock rate from a property. */
1518 device_property_read_u32(dev, "clock-frequency", &uartclk);
1519
1520 s->clk = devm_clk_get_optional(dev, NULL);
1521 if (IS_ERR(s->clk))
1522 return PTR_ERR(s->clk);
1523
1524 ret = clk_prepare_enable(s->clk);
1525 if (ret)
1526 return ret;
1527
1528 freq = clk_get_rate(s->clk);
1529 if (freq == 0) {
1530 if (uartclk)
1531 freq = uartclk;
1532 if (pfreq)
1533 freq = *pfreq;
1534 if (freq)
1535 dev_dbg(dev, "Clock frequency: %luHz\n", freq);
1536 else
1537 return -EINVAL;
1538 }
1539
1540 s->devtype = devtype;
1541 dev_set_drvdata(dev, s);
1542
1543 kthread_init_worker(&s->kworker);
1544 s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1545 "sc16is7xx");
1546 if (IS_ERR(s->kworker_task)) {
1547 ret = PTR_ERR(s->kworker_task);
1548 goto out_clk;
1549 }
1550 sched_set_fifo(s->kworker_task);
1551
1552 /* reset device, purging any pending irq / data */
1553 regmap_write(regmaps[0], SC16IS7XX_IOCONTROL_REG,
1554 SC16IS7XX_IOCONTROL_SRESET_BIT);
1555
1556 for (i = 0; i < devtype->nr_uart; ++i) {
1557 s->p[i].port.line = find_first_zero_bit(&sc16is7xx_lines,
1558 SC16IS7XX_MAX_DEVS);
1559 if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
1560 ret = -ERANGE;
1561 goto out_ports;
1562 }
1563
1564 /* Initialize port data */
1565 s->p[i].port.dev = dev;
1566 s->p[i].port.irq = irq;
1567 s->p[i].port.type = PORT_SC16IS7XX;
1568 s->p[i].port.fifosize = SC16IS7XX_FIFO_SIZE;
1569 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1570 s->p[i].port.iobase = i;
1571 /*
1572 * Use all ones as membase to make sure uart_configure_port() in
1573 * serial_core.c does not abort for SPI/I2C devices where the
1574 * membase address is not applicable.
1575 */
1576 s->p[i].port.membase = (void __iomem *)~0;
1577 s->p[i].port.iotype = UPIO_PORT;
1578 s->p[i].port.uartclk = freq;
1579 s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1580 s->p[i].port.rs485_supported = sc16is7xx_rs485_supported;
1581 s->p[i].port.ops = &sc16is7xx_ops;
1582 s->p[i].old_mctrl = 0;
1583 s->p[i].regmap = regmaps[i];
1584
1585 mutex_init(&s->p[i].efr_lock);
1586
1587 ret = uart_get_rs485_mode(&s->p[i].port);
1588 if (ret)
1589 goto out_ports;
1590
1591 /* Disable all interrupts */
1592 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1593 /* Disable TX/RX */
1594 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1595 SC16IS7XX_EFCR_RXDISABLE_BIT |
1596 SC16IS7XX_EFCR_TXDISABLE_BIT);
1597
1598 /* Initialize kthread work structs */
1599 kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1600 kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1601 kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc);
1602
1603 /* Register port */
1604 ret = uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1605 if (ret)
1606 goto out_ports;
1607
1608 set_bit(s->p[i].port.line, &sc16is7xx_lines);
1609
1610 /* Enable EFR */
1611 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
1612 SC16IS7XX_LCR_CONF_MODE_B);
1613
1614 regcache_cache_bypass(regmaps[i], true);
1615
1616 /* Enable write access to enhanced features */
1617 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
1618 SC16IS7XX_EFR_ENABLE_BIT);
1619
1620 regcache_cache_bypass(regmaps[i], false);
1621
1622 /* Restore access to general registers */
1623 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
1624
1625 /* Go to suspend mode */
1626 sc16is7xx_power(&s->p[i].port, 0);
1627 }
1628
1629 sc16is7xx_setup_irda_ports(s);
1630
1631 ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]);
1632 if (ret)
1633 goto out_ports;
1634
1635 #ifdef CONFIG_GPIOLIB
1636 ret = sc16is7xx_setup_gpio_chip(s);
1637 if (ret)
1638 goto out_ports;
1639 #endif
1640
1641 /*
1642 * Setup interrupt. We first try to acquire the IRQ line as level IRQ.
1643 * If that succeeds, we can allow sharing the interrupt as well.
1644 * In case the interrupt controller doesn't support that, we fall
1645 * back to a non-shared falling-edge trigger.
1646 */
1647 ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1648 IRQF_TRIGGER_LOW | IRQF_SHARED |
1649 IRQF_ONESHOT,
1650 dev_name(dev), s);
1651 if (!ret)
1652 return 0;
1653
1654 ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1655 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1656 dev_name(dev), s);
1657 if (!ret)
1658 return 0;
1659
1660 #ifdef CONFIG_GPIOLIB
1661 if (s->gpio_valid_mask)
1662 gpiochip_remove(&s->gpio);
1663 #endif
1664
1665 out_ports:
1666 for (i = 0; i < devtype->nr_uart; i++)
1667 if (test_and_clear_bit(s->p[i].port.line, &sc16is7xx_lines))
1668 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1669
1670 kthread_stop(s->kworker_task);
1671
1672 out_clk:
1673 clk_disable_unprepare(s->clk);
1674
1675 return ret;
1676 }
1677
sc16is7xx_remove(struct device * dev)1678 static void sc16is7xx_remove(struct device *dev)
1679 {
1680 struct sc16is7xx_port *s = dev_get_drvdata(dev);
1681 int i;
1682
1683 #ifdef CONFIG_GPIOLIB
1684 if (s->gpio_valid_mask)
1685 gpiochip_remove(&s->gpio);
1686 #endif
1687
1688 for (i = 0; i < s->devtype->nr_uart; i++) {
1689 kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
1690 if (test_and_clear_bit(s->p[i].port.line, &sc16is7xx_lines))
1691 uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1692 sc16is7xx_power(&s->p[i].port, 0);
1693 }
1694
1695 kthread_flush_worker(&s->kworker);
1696 kthread_stop(s->kworker_task);
1697
1698 clk_disable_unprepare(s->clk);
1699 }
1700
1701 static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1702 { .compatible = "nxp,sc16is740", .data = &sc16is74x_devtype, },
1703 { .compatible = "nxp,sc16is741", .data = &sc16is74x_devtype, },
1704 { .compatible = "nxp,sc16is750", .data = &sc16is750_devtype, },
1705 { .compatible = "nxp,sc16is752", .data = &sc16is752_devtype, },
1706 { .compatible = "nxp,sc16is760", .data = &sc16is760_devtype, },
1707 { .compatible = "nxp,sc16is762", .data = &sc16is762_devtype, },
1708 { }
1709 };
1710 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1711
1712 static struct regmap_config regcfg = {
1713 .reg_bits = 5,
1714 .pad_bits = 3,
1715 .val_bits = 8,
1716 .cache_type = REGCACHE_RBTREE,
1717 .volatile_reg = sc16is7xx_regmap_volatile,
1718 .precious_reg = sc16is7xx_regmap_precious,
1719 .writeable_noinc_reg = sc16is7xx_regmap_noinc,
1720 .readable_noinc_reg = sc16is7xx_regmap_noinc,
1721 .max_raw_read = SC16IS7XX_FIFO_SIZE,
1722 .max_raw_write = SC16IS7XX_FIFO_SIZE,
1723 .max_register = SC16IS7XX_EFCR_REG,
1724 };
1725
sc16is7xx_regmap_name(u8 port_id)1726 static const char *sc16is7xx_regmap_name(u8 port_id)
1727 {
1728 switch (port_id) {
1729 case 0: return "port0";
1730 case 1: return "port1";
1731 default:
1732 WARN_ON(true);
1733 return NULL;
1734 }
1735 }
1736
sc16is7xx_regmap_port_mask(unsigned int port_id)1737 static unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
1738 {
1739 /* CH1,CH0 are at bits 2:1. */
1740 return port_id << 1;
1741 }
1742
1743 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
sc16is7xx_spi_probe(struct spi_device * spi)1744 static int sc16is7xx_spi_probe(struct spi_device *spi)
1745 {
1746 const struct sc16is7xx_devtype *devtype;
1747 struct regmap *regmaps[2];
1748 unsigned int i;
1749 int ret;
1750
1751 /* Setup SPI bus */
1752 spi->bits_per_word = 8;
1753 /* For all variants, only mode 0 is supported */
1754 if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
1755 return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");
1756
1757 spi->mode = spi->mode ? : SPI_MODE_0;
1758 spi->max_speed_hz = spi->max_speed_hz ? : 4 * HZ_PER_MHZ;
1759 ret = spi_setup(spi);
1760 if (ret)
1761 return ret;
1762
1763 if (spi->dev.of_node) {
1764 devtype = device_get_match_data(&spi->dev);
1765 if (!devtype)
1766 return -ENODEV;
1767 } else {
1768 const struct spi_device_id *id_entry = spi_get_device_id(spi);
1769
1770 devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
1771 }
1772
1773 for (i = 0; i < devtype->nr_uart; i++) {
1774 regcfg.name = sc16is7xx_regmap_name(i);
1775 /*
1776 * If read_flag_mask is 0, the regmap code sets it to a default
1777 * of 0x80. Since we specify our own mask, we must add the READ
1778 * bit ourselves:
1779 */
1780 regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i) |
1781 SC16IS7XX_SPI_READ_BIT;
1782 regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
1783 regmaps[i] = devm_regmap_init_spi(spi, ®cfg);
1784 }
1785
1786 return sc16is7xx_probe(&spi->dev, devtype, regmaps, spi->irq);
1787 }
1788
sc16is7xx_spi_remove(struct spi_device * spi)1789 static void sc16is7xx_spi_remove(struct spi_device *spi)
1790 {
1791 sc16is7xx_remove(&spi->dev);
1792 }
1793
1794 static const struct spi_device_id sc16is7xx_spi_id_table[] = {
1795 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1796 { "sc16is740", (kernel_ulong_t)&sc16is74x_devtype, },
1797 { "sc16is741", (kernel_ulong_t)&sc16is74x_devtype, },
1798 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1799 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1800 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1801 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1802 { }
1803 };
1804
1805 MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
1806
1807 static struct spi_driver sc16is7xx_spi_uart_driver = {
1808 .driver = {
1809 .name = SC16IS7XX_NAME,
1810 .of_match_table = sc16is7xx_dt_ids,
1811 },
1812 .probe = sc16is7xx_spi_probe,
1813 .remove = sc16is7xx_spi_remove,
1814 .id_table = sc16is7xx_spi_id_table,
1815 };
1816
1817 MODULE_ALIAS("spi:sc16is7xx");
1818 #endif
1819
1820 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
sc16is7xx_i2c_probe(struct i2c_client * i2c)1821 static int sc16is7xx_i2c_probe(struct i2c_client *i2c)
1822 {
1823 const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
1824 const struct sc16is7xx_devtype *devtype;
1825 struct regmap *regmaps[2];
1826 unsigned int i;
1827
1828 if (i2c->dev.of_node) {
1829 devtype = device_get_match_data(&i2c->dev);
1830 if (!devtype)
1831 return -ENODEV;
1832 } else {
1833 devtype = (struct sc16is7xx_devtype *)id->driver_data;
1834 }
1835
1836 for (i = 0; i < devtype->nr_uart; i++) {
1837 regcfg.name = sc16is7xx_regmap_name(i);
1838 regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i);
1839 regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
1840 regmaps[i] = devm_regmap_init_i2c(i2c, ®cfg);
1841 }
1842
1843 return sc16is7xx_probe(&i2c->dev, devtype, regmaps, i2c->irq);
1844 }
1845
sc16is7xx_i2c_remove(struct i2c_client * client)1846 static void sc16is7xx_i2c_remove(struct i2c_client *client)
1847 {
1848 sc16is7xx_remove(&client->dev);
1849 }
1850
1851 static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
1852 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1853 { "sc16is740", (kernel_ulong_t)&sc16is74x_devtype, },
1854 { "sc16is741", (kernel_ulong_t)&sc16is74x_devtype, },
1855 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1856 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1857 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1858 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1859 { }
1860 };
1861 MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
1862
1863 static struct i2c_driver sc16is7xx_i2c_uart_driver = {
1864 .driver = {
1865 .name = SC16IS7XX_NAME,
1866 .of_match_table = sc16is7xx_dt_ids,
1867 },
1868 .probe = sc16is7xx_i2c_probe,
1869 .remove = sc16is7xx_i2c_remove,
1870 .id_table = sc16is7xx_i2c_id_table,
1871 };
1872
1873 #endif
1874
sc16is7xx_init(void)1875 static int __init sc16is7xx_init(void)
1876 {
1877 int ret;
1878
1879 ret = uart_register_driver(&sc16is7xx_uart);
1880 if (ret) {
1881 pr_err("Registering UART driver failed\n");
1882 return ret;
1883 }
1884
1885 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1886 ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
1887 if (ret < 0) {
1888 pr_err("failed to init sc16is7xx i2c --> %d\n", ret);
1889 goto err_i2c;
1890 }
1891 #endif
1892
1893 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1894 ret = spi_register_driver(&sc16is7xx_spi_uart_driver);
1895 if (ret < 0) {
1896 pr_err("failed to init sc16is7xx spi --> %d\n", ret);
1897 goto err_spi;
1898 }
1899 #endif
1900 return ret;
1901
1902 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1903 err_spi:
1904 #endif
1905 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1906 i2c_del_driver(&sc16is7xx_i2c_uart_driver);
1907 err_i2c:
1908 #endif
1909 uart_unregister_driver(&sc16is7xx_uart);
1910 return ret;
1911 }
1912 module_init(sc16is7xx_init);
1913
sc16is7xx_exit(void)1914 static void __exit sc16is7xx_exit(void)
1915 {
1916 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1917 i2c_del_driver(&sc16is7xx_i2c_uart_driver);
1918 #endif
1919
1920 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1921 spi_unregister_driver(&sc16is7xx_spi_uart_driver);
1922 #endif
1923 uart_unregister_driver(&sc16is7xx_uart);
1924 }
1925 module_exit(sc16is7xx_exit);
1926
1927 MODULE_LICENSE("GPL");
1928 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1929 MODULE_DESCRIPTION("SC16IS7XX serial driver");
1930