xref: /openbmc/linux/drivers/tty/serial/sc16is7xx.c (revision c0d3b831)
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/serial_core.h>
22 #include <linux/serial.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 #include <linux/spi/spi.h>
26 #include <linux/uaccess.h>
27 #include <uapi/linux/sched/types.h>
28 
29 #define SC16IS7XX_NAME			"sc16is7xx"
30 #define SC16IS7XX_MAX_DEVS		8
31 
32 /* SC16IS7XX register definitions */
33 #define SC16IS7XX_RHR_REG		(0x00) /* RX FIFO */
34 #define SC16IS7XX_THR_REG		(0x00) /* TX FIFO */
35 #define SC16IS7XX_IER_REG		(0x01) /* Interrupt enable */
36 #define SC16IS7XX_IIR_REG		(0x02) /* Interrupt Identification */
37 #define SC16IS7XX_FCR_REG		(0x02) /* FIFO control */
38 #define SC16IS7XX_LCR_REG		(0x03) /* Line Control */
39 #define SC16IS7XX_MCR_REG		(0x04) /* Modem Control */
40 #define SC16IS7XX_LSR_REG		(0x05) /* Line Status */
41 #define SC16IS7XX_MSR_REG		(0x06) /* Modem Status */
42 #define SC16IS7XX_SPR_REG		(0x07) /* Scratch Pad */
43 #define SC16IS7XX_TXLVL_REG		(0x08) /* TX FIFO level */
44 #define SC16IS7XX_RXLVL_REG		(0x09) /* RX FIFO level */
45 #define SC16IS7XX_IODIR_REG		(0x0a) /* I/O Direction
46 						* - only on 75x/76x
47 						*/
48 #define SC16IS7XX_IOSTATE_REG		(0x0b) /* I/O State
49 						* - only on 75x/76x
50 						*/
51 #define SC16IS7XX_IOINTENA_REG		(0x0c) /* I/O Interrupt Enable
52 						* - only on 75x/76x
53 						*/
54 #define SC16IS7XX_IOCONTROL_REG		(0x0e) /* I/O Control
55 						* - only on 75x/76x
56 						*/
57 #define SC16IS7XX_EFCR_REG		(0x0f) /* Extra Features Control */
58 
59 /* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
60 #define SC16IS7XX_TCR_REG		(0x06) /* Transmit control */
61 #define SC16IS7XX_TLR_REG		(0x07) /* Trigger level */
62 
63 /* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
64 #define SC16IS7XX_DLL_REG		(0x00) /* Divisor Latch Low */
65 #define SC16IS7XX_DLH_REG		(0x01) /* Divisor Latch High */
66 
67 /* Enhanced Register set: Only if (LCR == 0xBF) */
68 #define SC16IS7XX_EFR_REG		(0x02) /* Enhanced Features */
69 #define SC16IS7XX_XON1_REG		(0x04) /* Xon1 word */
70 #define SC16IS7XX_XON2_REG		(0x05) /* Xon2 word */
71 #define SC16IS7XX_XOFF1_REG		(0x06) /* Xoff1 word */
72 #define SC16IS7XX_XOFF2_REG		(0x07) /* Xoff2 word */
73 
74 /* IER register bits */
75 #define SC16IS7XX_IER_RDI_BIT		(1 << 0) /* Enable RX data interrupt */
76 #define SC16IS7XX_IER_THRI_BIT		(1 << 1) /* Enable TX holding register
77 						  * interrupt */
78 #define SC16IS7XX_IER_RLSI_BIT		(1 << 2) /* Enable RX line status
79 						  * interrupt */
80 #define SC16IS7XX_IER_MSI_BIT		(1 << 3) /* Enable Modem status
81 						  * interrupt */
82 
83 /* IER register bits - write only if (EFR[4] == 1) */
84 #define SC16IS7XX_IER_SLEEP_BIT		(1 << 4) /* Enable Sleep mode */
85 #define SC16IS7XX_IER_XOFFI_BIT		(1 << 5) /* Enable Xoff interrupt */
86 #define SC16IS7XX_IER_RTSI_BIT		(1 << 6) /* Enable nRTS interrupt */
87 #define SC16IS7XX_IER_CTSI_BIT		(1 << 7) /* Enable nCTS interrupt */
88 
89 /* FCR register bits */
90 #define SC16IS7XX_FCR_FIFO_BIT		(1 << 0) /* Enable FIFO */
91 #define SC16IS7XX_FCR_RXRESET_BIT	(1 << 1) /* Reset RX FIFO */
92 #define SC16IS7XX_FCR_TXRESET_BIT	(1 << 2) /* Reset TX FIFO */
93 #define SC16IS7XX_FCR_RXLVLL_BIT	(1 << 6) /* RX Trigger level LSB */
94 #define SC16IS7XX_FCR_RXLVLH_BIT	(1 << 7) /* RX Trigger level MSB */
95 
96 /* FCR register bits - write only if (EFR[4] == 1) */
97 #define SC16IS7XX_FCR_TXLVLL_BIT	(1 << 4) /* TX Trigger level LSB */
98 #define SC16IS7XX_FCR_TXLVLH_BIT	(1 << 5) /* TX Trigger level MSB */
99 
100 /* IIR register bits */
101 #define SC16IS7XX_IIR_NO_INT_BIT	(1 << 0) /* No interrupts pending */
102 #define SC16IS7XX_IIR_ID_MASK		0x3e     /* Mask for the interrupt ID */
103 #define SC16IS7XX_IIR_THRI_SRC		0x02     /* TX holding register empty */
104 #define SC16IS7XX_IIR_RDI_SRC		0x04     /* RX data interrupt */
105 #define SC16IS7XX_IIR_RLSE_SRC		0x06     /* RX line status error */
106 #define SC16IS7XX_IIR_RTOI_SRC		0x0c     /* RX time-out interrupt */
107 #define SC16IS7XX_IIR_MSI_SRC		0x00     /* Modem status interrupt
108 						  * - only on 75x/76x
109 						  */
110 #define SC16IS7XX_IIR_INPIN_SRC		0x30     /* Input pin change of state
111 						  * - only on 75x/76x
112 						  */
113 #define SC16IS7XX_IIR_XOFFI_SRC		0x10     /* Received Xoff */
114 #define SC16IS7XX_IIR_CTSRTS_SRC	0x20     /* nCTS,nRTS change of state
115 						  * from active (LOW)
116 						  * to inactive (HIGH)
117 						  */
118 /* LCR register bits */
119 #define SC16IS7XX_LCR_LENGTH0_BIT	(1 << 0) /* Word length bit 0 */
120 #define SC16IS7XX_LCR_LENGTH1_BIT	(1 << 1) /* Word length bit 1
121 						  *
122 						  * Word length bits table:
123 						  * 00 -> 5 bit words
124 						  * 01 -> 6 bit words
125 						  * 10 -> 7 bit words
126 						  * 11 -> 8 bit words
127 						  */
128 #define SC16IS7XX_LCR_STOPLEN_BIT	(1 << 2) /* STOP length bit
129 						  *
130 						  * STOP length bit table:
131 						  * 0 -> 1 stop bit
132 						  * 1 -> 1-1.5 stop bits if
133 						  *      word length is 5,
134 						  *      2 stop bits otherwise
135 						  */
136 #define SC16IS7XX_LCR_PARITY_BIT	(1 << 3) /* Parity bit enable */
137 #define SC16IS7XX_LCR_EVENPARITY_BIT	(1 << 4) /* Even parity bit enable */
138 #define SC16IS7XX_LCR_FORCEPARITY_BIT	(1 << 5) /* 9-bit multidrop parity */
139 #define SC16IS7XX_LCR_TXBREAK_BIT	(1 << 6) /* TX break enable */
140 #define SC16IS7XX_LCR_DLAB_BIT		(1 << 7) /* Divisor Latch enable */
141 #define SC16IS7XX_LCR_WORD_LEN_5	(0x00)
142 #define SC16IS7XX_LCR_WORD_LEN_6	(0x01)
143 #define SC16IS7XX_LCR_WORD_LEN_7	(0x02)
144 #define SC16IS7XX_LCR_WORD_LEN_8	(0x03)
145 #define SC16IS7XX_LCR_CONF_MODE_A	SC16IS7XX_LCR_DLAB_BIT /* Special
146 								* reg set */
147 #define SC16IS7XX_LCR_CONF_MODE_B	0xBF                   /* Enhanced
148 								* reg set */
149 
150 /* MCR register bits */
151 #define SC16IS7XX_MCR_DTR_BIT		(1 << 0) /* DTR complement
152 						  * - only on 75x/76x
153 						  */
154 #define SC16IS7XX_MCR_RTS_BIT		(1 << 1) /* RTS complement */
155 #define SC16IS7XX_MCR_TCRTLR_BIT	(1 << 2) /* TCR/TLR register enable */
156 #define SC16IS7XX_MCR_LOOP_BIT		(1 << 4) /* Enable loopback test mode */
157 #define SC16IS7XX_MCR_XONANY_BIT	(1 << 5) /* Enable Xon Any
158 						  * - write enabled
159 						  * if (EFR[4] == 1)
160 						  */
161 #define SC16IS7XX_MCR_IRDA_BIT		(1 << 6) /* Enable IrDA mode
162 						  * - write enabled
163 						  * if (EFR[4] == 1)
164 						  */
165 #define SC16IS7XX_MCR_CLKSEL_BIT	(1 << 7) /* Divide clock by 4
166 						  * - write enabled
167 						  * if (EFR[4] == 1)
168 						  */
169 
170 /* LSR register bits */
171 #define SC16IS7XX_LSR_DR_BIT		(1 << 0) /* Receiver data ready */
172 #define SC16IS7XX_LSR_OE_BIT		(1 << 1) /* Overrun Error */
173 #define SC16IS7XX_LSR_PE_BIT		(1 << 2) /* Parity Error */
174 #define SC16IS7XX_LSR_FE_BIT		(1 << 3) /* Frame Error */
175 #define SC16IS7XX_LSR_BI_BIT		(1 << 4) /* Break Interrupt */
176 #define SC16IS7XX_LSR_BRK_ERROR_MASK	0x1E     /* BI, FE, PE, OE bits */
177 #define SC16IS7XX_LSR_THRE_BIT		(1 << 5) /* TX holding register empty */
178 #define SC16IS7XX_LSR_TEMT_BIT		(1 << 6) /* Transmitter empty */
179 #define SC16IS7XX_LSR_FIFOE_BIT		(1 << 7) /* Fifo Error */
180 
181 /* MSR register bits */
182 #define SC16IS7XX_MSR_DCTS_BIT		(1 << 0) /* Delta CTS Clear To Send */
183 #define SC16IS7XX_MSR_DDSR_BIT		(1 << 1) /* Delta DSR Data Set Ready
184 						  * or (IO4)
185 						  * - only on 75x/76x
186 						  */
187 #define SC16IS7XX_MSR_DRI_BIT		(1 << 2) /* Delta RI Ring Indicator
188 						  * or (IO7)
189 						  * - only on 75x/76x
190 						  */
191 #define SC16IS7XX_MSR_DCD_BIT		(1 << 3) /* Delta CD Carrier Detect
192 						  * or (IO6)
193 						  * - only on 75x/76x
194 						  */
195 #define SC16IS7XX_MSR_CTS_BIT		(1 << 4) /* CTS */
196 #define SC16IS7XX_MSR_DSR_BIT		(1 << 5) /* DSR (IO4)
197 						  * - only on 75x/76x
198 						  */
199 #define SC16IS7XX_MSR_RI_BIT		(1 << 6) /* RI (IO7)
200 						  * - only on 75x/76x
201 						  */
202 #define SC16IS7XX_MSR_CD_BIT		(1 << 7) /* CD (IO6)
203 						  * - only on 75x/76x
204 						  */
205 #define SC16IS7XX_MSR_DELTA_MASK	0x0F     /* Any of the delta bits! */
206 
207 /*
208  * TCR register bits
209  * TCR trigger levels are available from 0 to 60 characters with a granularity
210  * of four.
211  * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
212  * no built-in hardware check to make sure this condition is met. Also, the TCR
213  * must be programmed with this condition before auto RTS or software flow
214  * control is enabled to avoid spurious operation of the device.
215  */
216 #define SC16IS7XX_TCR_RX_HALT(words)	((((words) / 4) & 0x0f) << 0)
217 #define SC16IS7XX_TCR_RX_RESUME(words)	((((words) / 4) & 0x0f) << 4)
218 
219 /*
220  * TLR register bits
221  * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
222  * FIFO Control Register (FCR) are used for the transmit and receive FIFO
223  * trigger levels. Trigger levels from 4 characters to 60 characters are
224  * available with a granularity of four.
225  *
226  * When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the
227  * trigger level setting defined in FCR. If TLR has non-zero trigger level value
228  * the trigger level defined in FCR is discarded. This applies to both transmit
229  * FIFO and receive FIFO trigger level setting.
230  *
231  * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
232  * default state, that is, '00'.
233  */
234 #define SC16IS7XX_TLR_TX_TRIGGER(words)	((((words) / 4) & 0x0f) << 0)
235 #define SC16IS7XX_TLR_RX_TRIGGER(words)	((((words) / 4) & 0x0f) << 4)
236 
237 /* IOControl register bits (Only 750/760) */
238 #define SC16IS7XX_IOCONTROL_LATCH_BIT	(1 << 0) /* Enable input latching */
239 #define SC16IS7XX_IOCONTROL_MODEM_BIT	(1 << 1) /* Enable GPIO[7:4] as modem pins */
240 #define SC16IS7XX_IOCONTROL_SRESET_BIT	(1 << 3) /* Software Reset */
241 
242 /* EFCR register bits */
243 #define SC16IS7XX_EFCR_9BIT_MODE_BIT	(1 << 0) /* Enable 9-bit or Multidrop
244 						  * mode (RS485) */
245 #define SC16IS7XX_EFCR_RXDISABLE_BIT	(1 << 1) /* Disable receiver */
246 #define SC16IS7XX_EFCR_TXDISABLE_BIT	(1 << 2) /* Disable transmitter */
247 #define SC16IS7XX_EFCR_AUTO_RS485_BIT	(1 << 4) /* Auto RS485 RTS direction */
248 #define SC16IS7XX_EFCR_RTS_INVERT_BIT	(1 << 5) /* RTS output inversion */
249 #define SC16IS7XX_EFCR_IRDA_MODE_BIT	(1 << 7) /* IrDA mode
250 						  * 0 = rate upto 115.2 kbit/s
251 						  *   - Only 750/760
252 						  * 1 = rate upto 1.152 Mbit/s
253 						  *   - Only 760
254 						  */
255 
256 /* EFR register bits */
257 #define SC16IS7XX_EFR_AUTORTS_BIT	(1 << 6) /* Auto RTS flow ctrl enable */
258 #define SC16IS7XX_EFR_AUTOCTS_BIT	(1 << 7) /* Auto CTS flow ctrl enable */
259 #define SC16IS7XX_EFR_XOFF2_DETECT_BIT	(1 << 5) /* Enable Xoff2 detection */
260 #define SC16IS7XX_EFR_ENABLE_BIT	(1 << 4) /* Enable enhanced functions
261 						  * and writing to IER[7:4],
262 						  * FCR[5:4], MCR[7:5]
263 						  */
264 #define SC16IS7XX_EFR_SWFLOW3_BIT	(1 << 3) /* SWFLOW bit 3 */
265 #define SC16IS7XX_EFR_SWFLOW2_BIT	(1 << 2) /* SWFLOW bit 2
266 						  *
267 						  * SWFLOW bits 3 & 2 table:
268 						  * 00 -> no transmitter flow
269 						  *       control
270 						  * 01 -> transmitter generates
271 						  *       XON2 and XOFF2
272 						  * 10 -> transmitter generates
273 						  *       XON1 and XOFF1
274 						  * 11 -> transmitter generates
275 						  *       XON1, XON2, XOFF1 and
276 						  *       XOFF2
277 						  */
278 #define SC16IS7XX_EFR_SWFLOW1_BIT	(1 << 1) /* SWFLOW bit 2 */
279 #define SC16IS7XX_EFR_SWFLOW0_BIT	(1 << 0) /* SWFLOW bit 3
280 						  *
281 						  * SWFLOW bits 3 & 2 table:
282 						  * 00 -> no received flow
283 						  *       control
284 						  * 01 -> receiver compares
285 						  *       XON2 and XOFF2
286 						  * 10 -> receiver compares
287 						  *       XON1 and XOFF1
288 						  * 11 -> receiver compares
289 						  *       XON1, XON2, XOFF1 and
290 						  *       XOFF2
291 						  */
292 #define SC16IS7XX_EFR_FLOWCTRL_BITS	(SC16IS7XX_EFR_AUTORTS_BIT | \
293 					SC16IS7XX_EFR_AUTOCTS_BIT | \
294 					SC16IS7XX_EFR_XOFF2_DETECT_BIT | \
295 					SC16IS7XX_EFR_SWFLOW3_BIT | \
296 					SC16IS7XX_EFR_SWFLOW2_BIT | \
297 					SC16IS7XX_EFR_SWFLOW1_BIT | \
298 					SC16IS7XX_EFR_SWFLOW0_BIT)
299 
300 
301 /* Misc definitions */
302 #define SC16IS7XX_FIFO_SIZE		(64)
303 #define SC16IS7XX_REG_SHIFT		2
304 
305 struct sc16is7xx_devtype {
306 	char	name[10];
307 	int	nr_gpio;
308 	int	nr_uart;
309 	int	has_mctrl;
310 };
311 
312 #define SC16IS7XX_RECONF_MD		(1 << 0)
313 #define SC16IS7XX_RECONF_IER		(1 << 1)
314 #define SC16IS7XX_RECONF_RS485		(1 << 2)
315 
316 struct sc16is7xx_one_config {
317 	unsigned int			flags;
318 	u8				ier_mask;
319 	u8				ier_val;
320 };
321 
322 struct sc16is7xx_one {
323 	struct uart_port		port;
324 	u8				line;
325 	struct kthread_work		tx_work;
326 	struct kthread_work		reg_work;
327 	struct kthread_delayed_work	ms_work;
328 	struct sc16is7xx_one_config	config;
329 	bool				irda_mode;
330 	unsigned int			old_mctrl;
331 };
332 
333 struct sc16is7xx_port {
334 	const struct sc16is7xx_devtype	*devtype;
335 	struct regmap			*regmap;
336 	struct clk			*clk;
337 #ifdef CONFIG_GPIOLIB
338 	struct gpio_chip		gpio;
339 #endif
340 	unsigned char			buf[SC16IS7XX_FIFO_SIZE];
341 	struct kthread_worker		kworker;
342 	struct task_struct		*kworker_task;
343 	struct mutex			efr_lock;
344 	struct sc16is7xx_one		p[];
345 };
346 
347 static unsigned long sc16is7xx_lines;
348 
349 static struct uart_driver sc16is7xx_uart = {
350 	.owner		= THIS_MODULE,
351 	.dev_name	= "ttySC",
352 	.nr		= SC16IS7XX_MAX_DEVS,
353 };
354 
355 static void sc16is7xx_ier_set(struct uart_port *port, u8 bit);
356 static void sc16is7xx_stop_tx(struct uart_port *port);
357 
358 #define to_sc16is7xx_port(p,e)	((container_of((p), struct sc16is7xx_port, e)))
359 #define to_sc16is7xx_one(p,e)	((container_of((p), struct sc16is7xx_one, e)))
360 
361 static int sc16is7xx_line(struct uart_port *port)
362 {
363 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
364 
365 	return one->line;
366 }
367 
368 static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
369 {
370 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
371 	unsigned int val = 0;
372 	const u8 line = sc16is7xx_line(port);
373 
374 	regmap_read(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line, &val);
375 
376 	return val;
377 }
378 
379 static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
380 {
381 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
382 	const u8 line = sc16is7xx_line(port);
383 
384 	regmap_write(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line, val);
385 }
386 
387 static void sc16is7xx_fifo_read(struct uart_port *port, unsigned int rxlen)
388 {
389 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
390 	const u8 line = sc16is7xx_line(port);
391 	u8 addr = (SC16IS7XX_RHR_REG << SC16IS7XX_REG_SHIFT) | line;
392 
393 	regcache_cache_bypass(s->regmap, true);
394 	regmap_raw_read(s->regmap, addr, s->buf, rxlen);
395 	regcache_cache_bypass(s->regmap, false);
396 }
397 
398 static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
399 {
400 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
401 	const u8 line = sc16is7xx_line(port);
402 	u8 addr = (SC16IS7XX_THR_REG << SC16IS7XX_REG_SHIFT) | line;
403 
404 	/*
405 	 * Don't send zero-length data, at least on SPI it confuses the chip
406 	 * delivering wrong TXLVL data.
407 	 */
408 	if (unlikely(!to_send))
409 		return;
410 
411 	regcache_cache_bypass(s->regmap, true);
412 	regmap_raw_write(s->regmap, addr, s->buf, to_send);
413 	regcache_cache_bypass(s->regmap, false);
414 }
415 
416 static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
417 				  u8 mask, u8 val)
418 {
419 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
420 	const u8 line = sc16is7xx_line(port);
421 
422 	regmap_update_bits(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line,
423 			   mask, val);
424 }
425 
426 static int sc16is7xx_alloc_line(void)
427 {
428 	int i;
429 
430 	BUILD_BUG_ON(SC16IS7XX_MAX_DEVS > BITS_PER_LONG);
431 
432 	for (i = 0; i < SC16IS7XX_MAX_DEVS; i++)
433 		if (!test_and_set_bit(i, &sc16is7xx_lines))
434 			break;
435 
436 	return i;
437 }
438 
439 static void sc16is7xx_power(struct uart_port *port, int on)
440 {
441 	sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
442 			      SC16IS7XX_IER_SLEEP_BIT,
443 			      on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
444 }
445 
446 static const struct sc16is7xx_devtype sc16is74x_devtype = {
447 	.name		= "SC16IS74X",
448 	.nr_gpio	= 0,
449 	.nr_uart	= 1,
450 	.has_mctrl	= 0,
451 };
452 
453 static const struct sc16is7xx_devtype sc16is750_devtype = {
454 	.name		= "SC16IS750",
455 	.nr_gpio	= 4,
456 	.nr_uart	= 1,
457 	.has_mctrl	= 1,
458 };
459 
460 static const struct sc16is7xx_devtype sc16is752_devtype = {
461 	.name		= "SC16IS752",
462 	.nr_gpio	= 0,
463 	.nr_uart	= 2,
464 	.has_mctrl	= 1,
465 };
466 
467 static const struct sc16is7xx_devtype sc16is760_devtype = {
468 	.name		= "SC16IS760",
469 	.nr_gpio	= 4,
470 	.nr_uart	= 1,
471 	.has_mctrl	= 1,
472 };
473 
474 static const struct sc16is7xx_devtype sc16is762_devtype = {
475 	.name		= "SC16IS762",
476 	.nr_gpio	= 0,
477 	.nr_uart	= 2,
478 	.has_mctrl	= 1,
479 };
480 
481 static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
482 {
483 	switch (reg >> SC16IS7XX_REG_SHIFT) {
484 	case SC16IS7XX_RHR_REG:
485 	case SC16IS7XX_IIR_REG:
486 	case SC16IS7XX_LSR_REG:
487 	case SC16IS7XX_MSR_REG:
488 	case SC16IS7XX_TXLVL_REG:
489 	case SC16IS7XX_RXLVL_REG:
490 	case SC16IS7XX_IOSTATE_REG:
491 		return true;
492 	default:
493 		break;
494 	}
495 
496 	return false;
497 }
498 
499 static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
500 {
501 	switch (reg >> SC16IS7XX_REG_SHIFT) {
502 	case SC16IS7XX_RHR_REG:
503 		return true;
504 	default:
505 		break;
506 	}
507 
508 	return false;
509 }
510 
511 static int sc16is7xx_set_baud(struct uart_port *port, int baud)
512 {
513 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
514 	u8 lcr;
515 	u8 prescaler = 0;
516 	unsigned long clk = port->uartclk, div = clk / 16 / baud;
517 
518 	if (div > 0xffff) {
519 		prescaler = SC16IS7XX_MCR_CLKSEL_BIT;
520 		div /= 4;
521 	}
522 
523 	/* In an amazing feat of design, the Enhanced Features Register shares
524 	 * the address of the Interrupt Identification Register, and is
525 	 * switched in by writing a magic value (0xbf) to the Line Control
526 	 * Register. Any interrupt firing during this time will see the EFR
527 	 * where it expects the IIR to be, leading to "Unexpected interrupt"
528 	 * messages.
529 	 *
530 	 * Prevent this possibility by claiming a mutex while accessing the
531 	 * EFR, and claiming the same mutex from within the interrupt handler.
532 	 * This is similar to disabling the interrupt, but that doesn't work
533 	 * because the bulk of the interrupt processing is run as a workqueue
534 	 * job in thread context.
535 	 */
536 	mutex_lock(&s->efr_lock);
537 
538 	lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
539 
540 	/* Open the LCR divisors for configuration */
541 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
542 			     SC16IS7XX_LCR_CONF_MODE_B);
543 
544 	/* Enable enhanced features */
545 	regcache_cache_bypass(s->regmap, true);
546 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
547 			      SC16IS7XX_EFR_ENABLE_BIT,
548 			      SC16IS7XX_EFR_ENABLE_BIT);
549 
550 	regcache_cache_bypass(s->regmap, false);
551 
552 	/* Put LCR back to the normal mode */
553 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
554 
555 	mutex_unlock(&s->efr_lock);
556 
557 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
558 			      SC16IS7XX_MCR_CLKSEL_BIT,
559 			      prescaler);
560 
561 	/* Open the LCR divisors for configuration */
562 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
563 			     SC16IS7XX_LCR_CONF_MODE_A);
564 
565 	/* Write the new divisor */
566 	regcache_cache_bypass(s->regmap, true);
567 	sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
568 	sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
569 	regcache_cache_bypass(s->regmap, false);
570 
571 	/* Put LCR back to the normal mode */
572 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
573 
574 	return DIV_ROUND_CLOSEST(clk / 16, div);
575 }
576 
577 static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
578 				unsigned int iir)
579 {
580 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
581 	unsigned int lsr = 0, ch, flag, bytes_read, i;
582 	bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
583 
584 	if (unlikely(rxlen >= sizeof(s->buf))) {
585 		dev_warn_ratelimited(port->dev,
586 				     "ttySC%i: Possible RX FIFO overrun: %d\n",
587 				     port->line, rxlen);
588 		port->icount.buf_overrun++;
589 		/* Ensure sanity of RX level */
590 		rxlen = sizeof(s->buf);
591 	}
592 
593 	while (rxlen) {
594 		/* Only read lsr if there are possible errors in FIFO */
595 		if (read_lsr) {
596 			lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
597 			if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
598 				read_lsr = false; /* No errors left in FIFO */
599 		} else
600 			lsr = 0;
601 
602 		if (read_lsr) {
603 			s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
604 			bytes_read = 1;
605 		} else {
606 			sc16is7xx_fifo_read(port, rxlen);
607 			bytes_read = rxlen;
608 		}
609 
610 		lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
611 
612 		port->icount.rx++;
613 		flag = TTY_NORMAL;
614 
615 		if (unlikely(lsr)) {
616 			if (lsr & SC16IS7XX_LSR_BI_BIT) {
617 				port->icount.brk++;
618 				if (uart_handle_break(port))
619 					continue;
620 			} else if (lsr & SC16IS7XX_LSR_PE_BIT)
621 				port->icount.parity++;
622 			else if (lsr & SC16IS7XX_LSR_FE_BIT)
623 				port->icount.frame++;
624 			else if (lsr & SC16IS7XX_LSR_OE_BIT)
625 				port->icount.overrun++;
626 
627 			lsr &= port->read_status_mask;
628 			if (lsr & SC16IS7XX_LSR_BI_BIT)
629 				flag = TTY_BREAK;
630 			else if (lsr & SC16IS7XX_LSR_PE_BIT)
631 				flag = TTY_PARITY;
632 			else if (lsr & SC16IS7XX_LSR_FE_BIT)
633 				flag = TTY_FRAME;
634 			else if (lsr & SC16IS7XX_LSR_OE_BIT)
635 				flag = TTY_OVERRUN;
636 		}
637 
638 		for (i = 0; i < bytes_read; ++i) {
639 			ch = s->buf[i];
640 			if (uart_handle_sysrq_char(port, ch))
641 				continue;
642 
643 			if (lsr & port->ignore_status_mask)
644 				continue;
645 
646 			uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
647 					 flag);
648 		}
649 		rxlen -= bytes_read;
650 	}
651 
652 	tty_flip_buffer_push(&port->state->port);
653 }
654 
655 static void sc16is7xx_handle_tx(struct uart_port *port)
656 {
657 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
658 	struct circ_buf *xmit = &port->state->xmit;
659 	unsigned int txlen, to_send, i;
660 	unsigned long flags;
661 
662 	if (unlikely(port->x_char)) {
663 		sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
664 		port->icount.tx++;
665 		port->x_char = 0;
666 		return;
667 	}
668 
669 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
670 		spin_lock_irqsave(&port->lock, flags);
671 		sc16is7xx_stop_tx(port);
672 		spin_unlock_irqrestore(&port->lock, flags);
673 		return;
674 	}
675 
676 	/* Get length of data pending in circular buffer */
677 	to_send = uart_circ_chars_pending(xmit);
678 	if (likely(to_send)) {
679 		/* Limit to size of TX FIFO */
680 		txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
681 		if (txlen > SC16IS7XX_FIFO_SIZE) {
682 			dev_err_ratelimited(port->dev,
683 				"chip reports %d free bytes in TX fifo, but it only has %d",
684 				txlen, SC16IS7XX_FIFO_SIZE);
685 			txlen = 0;
686 		}
687 		to_send = (to_send > txlen) ? txlen : to_send;
688 
689 		/* Convert to linear buffer */
690 		for (i = 0; i < to_send; ++i) {
691 			s->buf[i] = xmit->buf[xmit->tail];
692 			uart_xmit_advance(port, 1);
693 		}
694 
695 		sc16is7xx_fifo_write(port, to_send);
696 	}
697 
698 	spin_lock_irqsave(&port->lock, flags);
699 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
700 		uart_write_wakeup(port);
701 
702 	if (uart_circ_empty(xmit))
703 		sc16is7xx_stop_tx(port);
704 	spin_unlock_irqrestore(&port->lock, flags);
705 }
706 
707 static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
708 {
709 	u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
710 	unsigned int mctrl = 0;
711 
712 	mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
713 	mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0;
714 	mctrl |= (msr & SC16IS7XX_MSR_CD_BIT)  ? TIOCM_CAR : 0;
715 	mctrl |= (msr & SC16IS7XX_MSR_RI_BIT)  ? TIOCM_RNG : 0;
716 	return mctrl;
717 }
718 
719 static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
720 {
721 	struct uart_port *port = &one->port;
722 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
723 	unsigned long flags;
724 	unsigned int status, changed;
725 
726 	lockdep_assert_held_once(&s->efr_lock);
727 
728 	status = sc16is7xx_get_hwmctrl(port);
729 	changed = status ^ one->old_mctrl;
730 
731 	if (changed == 0)
732 		return;
733 
734 	one->old_mctrl = status;
735 
736 	spin_lock_irqsave(&port->lock, flags);
737 	if ((changed & TIOCM_RNG) && (status & TIOCM_RNG))
738 		port->icount.rng++;
739 	if (changed & TIOCM_DSR)
740 		port->icount.dsr++;
741 	if (changed & TIOCM_CAR)
742 		uart_handle_dcd_change(port, status & TIOCM_CAR);
743 	if (changed & TIOCM_CTS)
744 		uart_handle_cts_change(port, status & TIOCM_CTS);
745 
746 	wake_up_interruptible(&port->state->port.delta_msr_wait);
747 	spin_unlock_irqrestore(&port->lock, flags);
748 }
749 
750 static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
751 {
752 	struct uart_port *port = &s->p[portno].port;
753 
754 	do {
755 		unsigned int iir, rxlen;
756 		struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
757 
758 		iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
759 		if (iir & SC16IS7XX_IIR_NO_INT_BIT)
760 			return false;
761 
762 		iir &= SC16IS7XX_IIR_ID_MASK;
763 
764 		switch (iir) {
765 		case SC16IS7XX_IIR_RDI_SRC:
766 		case SC16IS7XX_IIR_RLSE_SRC:
767 		case SC16IS7XX_IIR_RTOI_SRC:
768 		case SC16IS7XX_IIR_XOFFI_SRC:
769 			rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
770 			if (rxlen)
771 				sc16is7xx_handle_rx(port, rxlen, iir);
772 			break;
773 		/* CTSRTS interrupt comes only when CTS goes inactive */
774 		case SC16IS7XX_IIR_CTSRTS_SRC:
775 		case SC16IS7XX_IIR_MSI_SRC:
776 			sc16is7xx_update_mlines(one);
777 			break;
778 		case SC16IS7XX_IIR_THRI_SRC:
779 			sc16is7xx_handle_tx(port);
780 			break;
781 		default:
782 			dev_err_ratelimited(port->dev,
783 					    "ttySC%i: Unexpected interrupt: %x",
784 					    port->line, iir);
785 			break;
786 		}
787 	} while (0);
788 	return true;
789 }
790 
791 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
792 {
793 	struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
794 
795 	mutex_lock(&s->efr_lock);
796 
797 	while (1) {
798 		bool keep_polling = false;
799 		int i;
800 
801 		for (i = 0; i < s->devtype->nr_uart; ++i)
802 			keep_polling |= sc16is7xx_port_irq(s, i);
803 		if (!keep_polling)
804 			break;
805 	}
806 
807 	mutex_unlock(&s->efr_lock);
808 
809 	return IRQ_HANDLED;
810 }
811 
812 static void sc16is7xx_tx_proc(struct kthread_work *ws)
813 {
814 	struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
815 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
816 	unsigned long flags;
817 
818 	if ((port->rs485.flags & SER_RS485_ENABLED) &&
819 	    (port->rs485.delay_rts_before_send > 0))
820 		msleep(port->rs485.delay_rts_before_send);
821 
822 	mutex_lock(&s->efr_lock);
823 	sc16is7xx_handle_tx(port);
824 	mutex_unlock(&s->efr_lock);
825 
826 	spin_lock_irqsave(&port->lock, flags);
827 	sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
828 	spin_unlock_irqrestore(&port->lock, flags);
829 }
830 
831 static void sc16is7xx_reconf_rs485(struct uart_port *port)
832 {
833 	const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
834 			 SC16IS7XX_EFCR_RTS_INVERT_BIT;
835 	u32 efcr = 0;
836 	struct serial_rs485 *rs485 = &port->rs485;
837 	unsigned long irqflags;
838 
839 	spin_lock_irqsave(&port->lock, irqflags);
840 	if (rs485->flags & SER_RS485_ENABLED) {
841 		efcr |=	SC16IS7XX_EFCR_AUTO_RS485_BIT;
842 
843 		if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
844 			efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
845 	}
846 	spin_unlock_irqrestore(&port->lock, irqflags);
847 
848 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
849 }
850 
851 static void sc16is7xx_reg_proc(struct kthread_work *ws)
852 {
853 	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
854 	struct sc16is7xx_one_config config;
855 	unsigned long irqflags;
856 
857 	spin_lock_irqsave(&one->port.lock, irqflags);
858 	config = one->config;
859 	memset(&one->config, 0, sizeof(one->config));
860 	spin_unlock_irqrestore(&one->port.lock, irqflags);
861 
862 	if (config.flags & SC16IS7XX_RECONF_MD) {
863 		u8 mcr = 0;
864 
865 		/* Device ignores RTS setting when hardware flow is enabled */
866 		if (one->port.mctrl & TIOCM_RTS)
867 			mcr |= SC16IS7XX_MCR_RTS_BIT;
868 
869 		if (one->port.mctrl & TIOCM_DTR)
870 			mcr |= SC16IS7XX_MCR_DTR_BIT;
871 
872 		if (one->port.mctrl & TIOCM_LOOP)
873 			mcr |= SC16IS7XX_MCR_LOOP_BIT;
874 		sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
875 				      SC16IS7XX_MCR_RTS_BIT |
876 				      SC16IS7XX_MCR_DTR_BIT |
877 				      SC16IS7XX_MCR_LOOP_BIT,
878 				      mcr);
879 	}
880 
881 	if (config.flags & SC16IS7XX_RECONF_IER)
882 		sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
883 				      config.ier_mask, config.ier_val);
884 
885 	if (config.flags & SC16IS7XX_RECONF_RS485)
886 		sc16is7xx_reconf_rs485(&one->port);
887 }
888 
889 static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
890 {
891 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
892 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
893 
894 	lockdep_assert_held_once(&port->lock);
895 
896 	one->config.flags |= SC16IS7XX_RECONF_IER;
897 	one->config.ier_mask |= bit;
898 	one->config.ier_val &= ~bit;
899 	kthread_queue_work(&s->kworker, &one->reg_work);
900 }
901 
902 static void sc16is7xx_ier_set(struct uart_port *port, u8 bit)
903 {
904 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
905 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
906 
907 	lockdep_assert_held_once(&port->lock);
908 
909 	one->config.flags |= SC16IS7XX_RECONF_IER;
910 	one->config.ier_mask |= bit;
911 	one->config.ier_val |= bit;
912 	kthread_queue_work(&s->kworker, &one->reg_work);
913 }
914 
915 static void sc16is7xx_stop_tx(struct uart_port *port)
916 {
917 	sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
918 }
919 
920 static void sc16is7xx_stop_rx(struct uart_port *port)
921 {
922 	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
923 }
924 
925 static void sc16is7xx_ms_proc(struct kthread_work *ws)
926 {
927 	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work);
928 	struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
929 
930 	if (one->port.state) {
931 		mutex_lock(&s->efr_lock);
932 		sc16is7xx_update_mlines(one);
933 		mutex_unlock(&s->efr_lock);
934 
935 		kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
936 	}
937 }
938 
939 static void sc16is7xx_enable_ms(struct uart_port *port)
940 {
941 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
942 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
943 
944 	lockdep_assert_held_once(&port->lock);
945 
946 	kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0);
947 }
948 
949 static void sc16is7xx_start_tx(struct uart_port *port)
950 {
951 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
952 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
953 
954 	kthread_queue_work(&s->kworker, &one->tx_work);
955 }
956 
957 static void sc16is7xx_throttle(struct uart_port *port)
958 {
959 	unsigned long flags;
960 
961 	/*
962 	 * Hardware flow control is enabled and thus the device ignores RTS
963 	 * value set in MCR register. Stop reading data from RX FIFO so the
964 	 * AutoRTS feature will de-activate RTS output.
965 	 */
966 	spin_lock_irqsave(&port->lock, flags);
967 	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
968 	spin_unlock_irqrestore(&port->lock, flags);
969 }
970 
971 static void sc16is7xx_unthrottle(struct uart_port *port)
972 {
973 	unsigned long flags;
974 
975 	spin_lock_irqsave(&port->lock, flags);
976 	sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT);
977 	spin_unlock_irqrestore(&port->lock, flags);
978 }
979 
980 static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
981 {
982 	unsigned int lsr;
983 
984 	lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
985 
986 	return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
987 }
988 
989 static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
990 {
991 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
992 
993 	/* Called with port lock taken so we can only return cached value */
994 	return one->old_mctrl;
995 }
996 
997 static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
998 {
999 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1000 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1001 
1002 	one->config.flags |= SC16IS7XX_RECONF_MD;
1003 	kthread_queue_work(&s->kworker, &one->reg_work);
1004 }
1005 
1006 static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
1007 {
1008 	sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
1009 			      SC16IS7XX_LCR_TXBREAK_BIT,
1010 			      break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
1011 }
1012 
1013 static void sc16is7xx_set_termios(struct uart_port *port,
1014 				  struct ktermios *termios,
1015 				  const struct ktermios *old)
1016 {
1017 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1018 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1019 	unsigned int lcr, flow = 0;
1020 	int baud;
1021 	unsigned long flags;
1022 
1023 	kthread_cancel_delayed_work_sync(&one->ms_work);
1024 
1025 	/* Mask termios capabilities we don't support */
1026 	termios->c_cflag &= ~CMSPAR;
1027 
1028 	/* Word size */
1029 	switch (termios->c_cflag & CSIZE) {
1030 	case CS5:
1031 		lcr = SC16IS7XX_LCR_WORD_LEN_5;
1032 		break;
1033 	case CS6:
1034 		lcr = SC16IS7XX_LCR_WORD_LEN_6;
1035 		break;
1036 	case CS7:
1037 		lcr = SC16IS7XX_LCR_WORD_LEN_7;
1038 		break;
1039 	case CS8:
1040 		lcr = SC16IS7XX_LCR_WORD_LEN_8;
1041 		break;
1042 	default:
1043 		lcr = SC16IS7XX_LCR_WORD_LEN_8;
1044 		termios->c_cflag &= ~CSIZE;
1045 		termios->c_cflag |= CS8;
1046 		break;
1047 	}
1048 
1049 	/* Parity */
1050 	if (termios->c_cflag & PARENB) {
1051 		lcr |= SC16IS7XX_LCR_PARITY_BIT;
1052 		if (!(termios->c_cflag & PARODD))
1053 			lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
1054 	}
1055 
1056 	/* Stop bits */
1057 	if (termios->c_cflag & CSTOPB)
1058 		lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
1059 
1060 	/* Set read status mask */
1061 	port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
1062 	if (termios->c_iflag & INPCK)
1063 		port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
1064 					  SC16IS7XX_LSR_FE_BIT;
1065 	if (termios->c_iflag & (BRKINT | PARMRK))
1066 		port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
1067 
1068 	/* Set status ignore mask */
1069 	port->ignore_status_mask = 0;
1070 	if (termios->c_iflag & IGNBRK)
1071 		port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
1072 	if (!(termios->c_cflag & CREAD))
1073 		port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
1074 
1075 	/* As above, claim the mutex while accessing the EFR. */
1076 	mutex_lock(&s->efr_lock);
1077 
1078 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
1079 			     SC16IS7XX_LCR_CONF_MODE_B);
1080 
1081 	/* Configure flow control */
1082 	regcache_cache_bypass(s->regmap, true);
1083 	sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
1084 	sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
1085 
1086 	port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
1087 	if (termios->c_cflag & CRTSCTS) {
1088 		flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
1089 			SC16IS7XX_EFR_AUTORTS_BIT;
1090 		port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1091 	}
1092 	if (termios->c_iflag & IXON)
1093 		flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
1094 	if (termios->c_iflag & IXOFF)
1095 		flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
1096 
1097 	sc16is7xx_port_update(port,
1098 			      SC16IS7XX_EFR_REG,
1099 			      SC16IS7XX_EFR_FLOWCTRL_BITS,
1100 			      flow);
1101 	regcache_cache_bypass(s->regmap, false);
1102 
1103 	/* Update LCR register */
1104 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
1105 
1106 	mutex_unlock(&s->efr_lock);
1107 
1108 	/* Get baud rate generator configuration */
1109 	baud = uart_get_baud_rate(port, termios, old,
1110 				  port->uartclk / 16 / 4 / 0xffff,
1111 				  port->uartclk / 16);
1112 
1113 	/* Setup baudrate generator */
1114 	baud = sc16is7xx_set_baud(port, baud);
1115 
1116 	spin_lock_irqsave(&port->lock, flags);
1117 
1118 	/* Update timeout according to new baud rate */
1119 	uart_update_timeout(port, termios->c_cflag, baud);
1120 
1121 	if (UART_ENABLE_MS(port, termios->c_cflag))
1122 		sc16is7xx_enable_ms(port);
1123 
1124 	spin_unlock_irqrestore(&port->lock, flags);
1125 }
1126 
1127 static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios,
1128 				  struct serial_rs485 *rs485)
1129 {
1130 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1131 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1132 
1133 	if (rs485->flags & SER_RS485_ENABLED) {
1134 		/*
1135 		 * RTS signal is handled by HW, it's timing can't be influenced.
1136 		 * However, it's sometimes useful to delay TX even without RTS
1137 		 * control therefore we try to handle .delay_rts_before_send.
1138 		 */
1139 		if (rs485->delay_rts_after_send)
1140 			return -EINVAL;
1141 	}
1142 
1143 	one->config.flags |= SC16IS7XX_RECONF_RS485;
1144 	kthread_queue_work(&s->kworker, &one->reg_work);
1145 
1146 	return 0;
1147 }
1148 
1149 static int sc16is7xx_startup(struct uart_port *port)
1150 {
1151 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1152 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1153 	unsigned int val;
1154 	unsigned long flags;
1155 
1156 	sc16is7xx_power(port, 1);
1157 
1158 	/* Reset FIFOs*/
1159 	val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
1160 	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
1161 	udelay(5);
1162 	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
1163 			     SC16IS7XX_FCR_FIFO_BIT);
1164 
1165 	/* Enable EFR */
1166 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
1167 			     SC16IS7XX_LCR_CONF_MODE_B);
1168 
1169 	regcache_cache_bypass(s->regmap, true);
1170 
1171 	/* Enable write access to enhanced features and internal clock div */
1172 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1173 			      SC16IS7XX_EFR_ENABLE_BIT,
1174 			      SC16IS7XX_EFR_ENABLE_BIT);
1175 
1176 	/* Enable TCR/TLR */
1177 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1178 			      SC16IS7XX_MCR_TCRTLR_BIT,
1179 			      SC16IS7XX_MCR_TCRTLR_BIT);
1180 
1181 	/* Configure flow control levels */
1182 	/* Flow control halt level 48, resume level 24 */
1183 	sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
1184 			     SC16IS7XX_TCR_RX_RESUME(24) |
1185 			     SC16IS7XX_TCR_RX_HALT(48));
1186 
1187 	regcache_cache_bypass(s->regmap, false);
1188 
1189 	/* Now, initialize the UART */
1190 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
1191 
1192 	/* Enable IrDA mode if requested in DT */
1193 	/* This bit must be written with LCR[7] = 0 */
1194 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1195 			      SC16IS7XX_MCR_IRDA_BIT,
1196 			      one->irda_mode ?
1197 				SC16IS7XX_MCR_IRDA_BIT : 0);
1198 
1199 	/* Enable the Rx and Tx FIFO */
1200 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1201 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1202 			      SC16IS7XX_EFCR_TXDISABLE_BIT,
1203 			      0);
1204 
1205 	/* Enable RX, CTS change and modem lines interrupts */
1206 	val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT |
1207 	      SC16IS7XX_IER_MSI_BIT;
1208 	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1209 
1210 	/* Enable modem status polling */
1211 	spin_lock_irqsave(&port->lock, flags);
1212 	sc16is7xx_enable_ms(port);
1213 	spin_unlock_irqrestore(&port->lock, flags);
1214 
1215 	return 0;
1216 }
1217 
1218 static void sc16is7xx_shutdown(struct uart_port *port)
1219 {
1220 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1221 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1222 
1223 	kthread_cancel_delayed_work_sync(&one->ms_work);
1224 
1225 	/* Disable all interrupts */
1226 	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1227 	/* Disable TX/RX */
1228 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1229 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1230 			      SC16IS7XX_EFCR_TXDISABLE_BIT,
1231 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1232 			      SC16IS7XX_EFCR_TXDISABLE_BIT);
1233 
1234 	sc16is7xx_power(port, 0);
1235 
1236 	kthread_flush_worker(&s->kworker);
1237 }
1238 
1239 static const char *sc16is7xx_type(struct uart_port *port)
1240 {
1241 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1242 
1243 	return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1244 }
1245 
1246 static int sc16is7xx_request_port(struct uart_port *port)
1247 {
1248 	/* Do nothing */
1249 	return 0;
1250 }
1251 
1252 static void sc16is7xx_config_port(struct uart_port *port, int flags)
1253 {
1254 	if (flags & UART_CONFIG_TYPE)
1255 		port->type = PORT_SC16IS7XX;
1256 }
1257 
1258 static int sc16is7xx_verify_port(struct uart_port *port,
1259 				 struct serial_struct *s)
1260 {
1261 	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1262 		return -EINVAL;
1263 	if (s->irq != port->irq)
1264 		return -EINVAL;
1265 
1266 	return 0;
1267 }
1268 
1269 static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1270 			 unsigned int oldstate)
1271 {
1272 	sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1273 }
1274 
1275 static void sc16is7xx_null_void(struct uart_port *port)
1276 {
1277 	/* Do nothing */
1278 }
1279 
1280 static const struct uart_ops sc16is7xx_ops = {
1281 	.tx_empty	= sc16is7xx_tx_empty,
1282 	.set_mctrl	= sc16is7xx_set_mctrl,
1283 	.get_mctrl	= sc16is7xx_get_mctrl,
1284 	.stop_tx	= sc16is7xx_stop_tx,
1285 	.start_tx	= sc16is7xx_start_tx,
1286 	.throttle	= sc16is7xx_throttle,
1287 	.unthrottle	= sc16is7xx_unthrottle,
1288 	.stop_rx	= sc16is7xx_stop_rx,
1289 	.enable_ms	= sc16is7xx_enable_ms,
1290 	.break_ctl	= sc16is7xx_break_ctl,
1291 	.startup	= sc16is7xx_startup,
1292 	.shutdown	= sc16is7xx_shutdown,
1293 	.set_termios	= sc16is7xx_set_termios,
1294 	.type		= sc16is7xx_type,
1295 	.request_port	= sc16is7xx_request_port,
1296 	.release_port	= sc16is7xx_null_void,
1297 	.config_port	= sc16is7xx_config_port,
1298 	.verify_port	= sc16is7xx_verify_port,
1299 	.pm		= sc16is7xx_pm,
1300 };
1301 
1302 #ifdef CONFIG_GPIOLIB
1303 static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1304 {
1305 	unsigned int val;
1306 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1307 	struct uart_port *port = &s->p[0].port;
1308 
1309 	val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1310 
1311 	return !!(val & BIT(offset));
1312 }
1313 
1314 static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1315 {
1316 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1317 	struct uart_port *port = &s->p[0].port;
1318 
1319 	sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1320 			      val ? BIT(offset) : 0);
1321 }
1322 
1323 static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1324 					  unsigned offset)
1325 {
1326 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1327 	struct uart_port *port = &s->p[0].port;
1328 
1329 	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1330 
1331 	return 0;
1332 }
1333 
1334 static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1335 					   unsigned offset, int val)
1336 {
1337 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1338 	struct uart_port *port = &s->p[0].port;
1339 	u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1340 
1341 	if (val)
1342 		state |= BIT(offset);
1343 	else
1344 		state &= ~BIT(offset);
1345 	sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
1346 	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1347 			      BIT(offset));
1348 
1349 	return 0;
1350 }
1351 #endif
1352 
1353 static const struct serial_rs485 sc16is7xx_rs485_supported = {
1354 	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
1355 	.delay_rts_before_send = 1,
1356 	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
1357 };
1358 
1359 static int sc16is7xx_probe(struct device *dev,
1360 			   const struct sc16is7xx_devtype *devtype,
1361 			   struct regmap *regmap, int irq)
1362 {
1363 	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
1364 	unsigned int val;
1365 	u32 uartclk = 0;
1366 	int i, ret;
1367 	struct sc16is7xx_port *s;
1368 
1369 	if (IS_ERR(regmap))
1370 		return PTR_ERR(regmap);
1371 
1372 	/*
1373 	 * This device does not have an identification register that would
1374 	 * tell us if we are really connected to the correct device.
1375 	 * The best we can do is to check if communication is at all possible.
1376 	 */
1377 	ret = regmap_read(regmap,
1378 			  SC16IS7XX_LSR_REG << SC16IS7XX_REG_SHIFT, &val);
1379 	if (ret < 0)
1380 		return -EPROBE_DEFER;
1381 
1382 	/* Alloc port structure */
1383 	s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
1384 	if (!s) {
1385 		dev_err(dev, "Error allocating port structure\n");
1386 		return -ENOMEM;
1387 	}
1388 
1389 	/* Always ask for fixed clock rate from a property. */
1390 	device_property_read_u32(dev, "clock-frequency", &uartclk);
1391 
1392 	s->clk = devm_clk_get_optional(dev, NULL);
1393 	if (IS_ERR(s->clk))
1394 		return PTR_ERR(s->clk);
1395 
1396 	ret = clk_prepare_enable(s->clk);
1397 	if (ret)
1398 		return ret;
1399 
1400 	freq = clk_get_rate(s->clk);
1401 	if (freq == 0) {
1402 		if (uartclk)
1403 			freq = uartclk;
1404 		if (pfreq)
1405 			freq = *pfreq;
1406 		if (freq)
1407 			dev_dbg(dev, "Clock frequency: %luHz\n", freq);
1408 		else
1409 			return -EINVAL;
1410 	}
1411 
1412 	s->regmap = regmap;
1413 	s->devtype = devtype;
1414 	dev_set_drvdata(dev, s);
1415 	mutex_init(&s->efr_lock);
1416 
1417 	kthread_init_worker(&s->kworker);
1418 	s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1419 				      "sc16is7xx");
1420 	if (IS_ERR(s->kworker_task)) {
1421 		ret = PTR_ERR(s->kworker_task);
1422 		goto out_clk;
1423 	}
1424 	sched_set_fifo(s->kworker_task);
1425 
1426 #ifdef CONFIG_GPIOLIB
1427 	if (devtype->nr_gpio) {
1428 		/* Setup GPIO cotroller */
1429 		s->gpio.owner		 = THIS_MODULE;
1430 		s->gpio.parent		 = dev;
1431 		s->gpio.label		 = dev_name(dev);
1432 		s->gpio.direction_input	 = sc16is7xx_gpio_direction_input;
1433 		s->gpio.get		 = sc16is7xx_gpio_get;
1434 		s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1435 		s->gpio.set		 = sc16is7xx_gpio_set;
1436 		s->gpio.base		 = -1;
1437 		s->gpio.ngpio		 = devtype->nr_gpio;
1438 		s->gpio.can_sleep	 = 1;
1439 		ret = gpiochip_add_data(&s->gpio, s);
1440 		if (ret)
1441 			goto out_thread;
1442 	}
1443 #endif
1444 
1445 	/* reset device, purging any pending irq / data */
1446 	regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
1447 			SC16IS7XX_IOCONTROL_SRESET_BIT);
1448 
1449 	for (i = 0; i < devtype->nr_uart; ++i) {
1450 		s->p[i].line		= i;
1451 		/* Initialize port data */
1452 		s->p[i].port.dev	= dev;
1453 		s->p[i].port.irq	= irq;
1454 		s->p[i].port.type	= PORT_SC16IS7XX;
1455 		s->p[i].port.fifosize	= SC16IS7XX_FIFO_SIZE;
1456 		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1457 		s->p[i].port.iobase	= i;
1458 		s->p[i].port.iotype	= UPIO_PORT;
1459 		s->p[i].port.uartclk	= freq;
1460 		s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1461 		s->p[i].port.rs485_supported = sc16is7xx_rs485_supported;
1462 		s->p[i].port.ops	= &sc16is7xx_ops;
1463 		s->p[i].old_mctrl	= 0;
1464 		s->p[i].port.line	= sc16is7xx_alloc_line();
1465 
1466 		if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
1467 			ret = -ENOMEM;
1468 			goto out_ports;
1469 		}
1470 
1471 		/* Disable all interrupts */
1472 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1473 		/* Disable TX/RX */
1474 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1475 				     SC16IS7XX_EFCR_RXDISABLE_BIT |
1476 				     SC16IS7XX_EFCR_TXDISABLE_BIT);
1477 
1478 		/* Use GPIO lines as modem status registers */
1479 		if (devtype->has_mctrl)
1480 			sc16is7xx_port_write(&s->p[i].port,
1481 					     SC16IS7XX_IOCONTROL_REG,
1482 					     SC16IS7XX_IOCONTROL_MODEM_BIT);
1483 
1484 		/* Initialize kthread work structs */
1485 		kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1486 		kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1487 		kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc);
1488 		/* Register port */
1489 		uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1490 
1491 		/* Enable EFR */
1492 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
1493 				     SC16IS7XX_LCR_CONF_MODE_B);
1494 
1495 		regcache_cache_bypass(s->regmap, true);
1496 
1497 		/* Enable write access to enhanced features */
1498 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
1499 				     SC16IS7XX_EFR_ENABLE_BIT);
1500 
1501 		regcache_cache_bypass(s->regmap, false);
1502 
1503 		/* Restore access to general registers */
1504 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
1505 
1506 		/* Go to suspend mode */
1507 		sc16is7xx_power(&s->p[i].port, 0);
1508 	}
1509 
1510 	if (dev->of_node) {
1511 		struct property *prop;
1512 		const __be32 *p;
1513 		u32 u;
1514 
1515 		of_property_for_each_u32(dev->of_node, "irda-mode-ports",
1516 					 prop, p, u)
1517 			if (u < devtype->nr_uart)
1518 				s->p[u].irda_mode = true;
1519 	}
1520 
1521 	/*
1522 	 * Setup interrupt. We first try to acquire the IRQ line as level IRQ.
1523 	 * If that succeeds, we can allow sharing the interrupt as well.
1524 	 * In case the interrupt controller doesn't support that, we fall
1525 	 * back to a non-shared falling-edge trigger.
1526 	 */
1527 	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1528 					IRQF_TRIGGER_LOW | IRQF_SHARED |
1529 					IRQF_ONESHOT,
1530 					dev_name(dev), s);
1531 	if (!ret)
1532 		return 0;
1533 
1534 	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1535 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1536 					dev_name(dev), s);
1537 	if (!ret)
1538 		return 0;
1539 
1540 out_ports:
1541 	for (i--; i >= 0; i--) {
1542 		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1543 		clear_bit(s->p[i].port.line, &sc16is7xx_lines);
1544 	}
1545 
1546 #ifdef CONFIG_GPIOLIB
1547 	if (devtype->nr_gpio)
1548 		gpiochip_remove(&s->gpio);
1549 
1550 out_thread:
1551 #endif
1552 	kthread_stop(s->kworker_task);
1553 
1554 out_clk:
1555 	clk_disable_unprepare(s->clk);
1556 
1557 	return ret;
1558 }
1559 
1560 static void sc16is7xx_remove(struct device *dev)
1561 {
1562 	struct sc16is7xx_port *s = dev_get_drvdata(dev);
1563 	int i;
1564 
1565 #ifdef CONFIG_GPIOLIB
1566 	if (s->devtype->nr_gpio)
1567 		gpiochip_remove(&s->gpio);
1568 #endif
1569 
1570 	for (i = 0; i < s->devtype->nr_uart; i++) {
1571 		kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
1572 		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1573 		clear_bit(s->p[i].port.line, &sc16is7xx_lines);
1574 		sc16is7xx_power(&s->p[i].port, 0);
1575 	}
1576 
1577 	kthread_flush_worker(&s->kworker);
1578 	kthread_stop(s->kworker_task);
1579 
1580 	clk_disable_unprepare(s->clk);
1581 }
1582 
1583 static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1584 	{ .compatible = "nxp,sc16is740",	.data = &sc16is74x_devtype, },
1585 	{ .compatible = "nxp,sc16is741",	.data = &sc16is74x_devtype, },
1586 	{ .compatible = "nxp,sc16is750",	.data = &sc16is750_devtype, },
1587 	{ .compatible = "nxp,sc16is752",	.data = &sc16is752_devtype, },
1588 	{ .compatible = "nxp,sc16is760",	.data = &sc16is760_devtype, },
1589 	{ .compatible = "nxp,sc16is762",	.data = &sc16is762_devtype, },
1590 	{ }
1591 };
1592 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1593 
1594 static struct regmap_config regcfg = {
1595 	.reg_bits = 7,
1596 	.pad_bits = 1,
1597 	.val_bits = 8,
1598 	.cache_type = REGCACHE_RBTREE,
1599 	.volatile_reg = sc16is7xx_regmap_volatile,
1600 	.precious_reg = sc16is7xx_regmap_precious,
1601 };
1602 
1603 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1604 static int sc16is7xx_spi_probe(struct spi_device *spi)
1605 {
1606 	const struct sc16is7xx_devtype *devtype;
1607 	struct regmap *regmap;
1608 	int ret;
1609 
1610 	/* Setup SPI bus */
1611 	spi->bits_per_word	= 8;
1612 	/* only supports mode 0 on SC16IS762 */
1613 	spi->mode		= spi->mode ? : SPI_MODE_0;
1614 	spi->max_speed_hz	= spi->max_speed_hz ? : 15000000;
1615 	ret = spi_setup(spi);
1616 	if (ret)
1617 		return ret;
1618 
1619 	if (spi->dev.of_node) {
1620 		devtype = device_get_match_data(&spi->dev);
1621 		if (!devtype)
1622 			return -ENODEV;
1623 	} else {
1624 		const struct spi_device_id *id_entry = spi_get_device_id(spi);
1625 
1626 		devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
1627 	}
1628 
1629 	regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1630 			      (devtype->nr_uart - 1);
1631 	regmap = devm_regmap_init_spi(spi, &regcfg);
1632 
1633 	return sc16is7xx_probe(&spi->dev, devtype, regmap, spi->irq);
1634 }
1635 
1636 static void sc16is7xx_spi_remove(struct spi_device *spi)
1637 {
1638 	sc16is7xx_remove(&spi->dev);
1639 }
1640 
1641 static const struct spi_device_id sc16is7xx_spi_id_table[] = {
1642 	{ "sc16is74x",	(kernel_ulong_t)&sc16is74x_devtype, },
1643 	{ "sc16is740",	(kernel_ulong_t)&sc16is74x_devtype, },
1644 	{ "sc16is741",	(kernel_ulong_t)&sc16is74x_devtype, },
1645 	{ "sc16is750",	(kernel_ulong_t)&sc16is750_devtype, },
1646 	{ "sc16is752",	(kernel_ulong_t)&sc16is752_devtype, },
1647 	{ "sc16is760",	(kernel_ulong_t)&sc16is760_devtype, },
1648 	{ "sc16is762",	(kernel_ulong_t)&sc16is762_devtype, },
1649 	{ }
1650 };
1651 
1652 MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
1653 
1654 static struct spi_driver sc16is7xx_spi_uart_driver = {
1655 	.driver = {
1656 		.name		= SC16IS7XX_NAME,
1657 		.of_match_table	= sc16is7xx_dt_ids,
1658 	},
1659 	.probe		= sc16is7xx_spi_probe,
1660 	.remove		= sc16is7xx_spi_remove,
1661 	.id_table	= sc16is7xx_spi_id_table,
1662 };
1663 
1664 MODULE_ALIAS("spi:sc16is7xx");
1665 #endif
1666 
1667 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1668 static int sc16is7xx_i2c_probe(struct i2c_client *i2c,
1669 			       const struct i2c_device_id *id)
1670 {
1671 	const struct sc16is7xx_devtype *devtype;
1672 	struct regmap *regmap;
1673 
1674 	if (i2c->dev.of_node) {
1675 		devtype = device_get_match_data(&i2c->dev);
1676 		if (!devtype)
1677 			return -ENODEV;
1678 	} else {
1679 		devtype = (struct sc16is7xx_devtype *)id->driver_data;
1680 	}
1681 
1682 	regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1683 			      (devtype->nr_uart - 1);
1684 	regmap = devm_regmap_init_i2c(i2c, &regcfg);
1685 
1686 	return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq);
1687 }
1688 
1689 static void sc16is7xx_i2c_remove(struct i2c_client *client)
1690 {
1691 	sc16is7xx_remove(&client->dev);
1692 }
1693 
1694 static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
1695 	{ "sc16is74x",	(kernel_ulong_t)&sc16is74x_devtype, },
1696 	{ "sc16is740",	(kernel_ulong_t)&sc16is74x_devtype, },
1697 	{ "sc16is741",	(kernel_ulong_t)&sc16is74x_devtype, },
1698 	{ "sc16is750",	(kernel_ulong_t)&sc16is750_devtype, },
1699 	{ "sc16is752",	(kernel_ulong_t)&sc16is752_devtype, },
1700 	{ "sc16is760",	(kernel_ulong_t)&sc16is760_devtype, },
1701 	{ "sc16is762",	(kernel_ulong_t)&sc16is762_devtype, },
1702 	{ }
1703 };
1704 MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
1705 
1706 static struct i2c_driver sc16is7xx_i2c_uart_driver = {
1707 	.driver = {
1708 		.name		= SC16IS7XX_NAME,
1709 		.of_match_table	= sc16is7xx_dt_ids,
1710 	},
1711 	.probe		= sc16is7xx_i2c_probe,
1712 	.remove		= sc16is7xx_i2c_remove,
1713 	.id_table	= sc16is7xx_i2c_id_table,
1714 };
1715 
1716 #endif
1717 
1718 static int __init sc16is7xx_init(void)
1719 {
1720 	int ret;
1721 
1722 	ret = uart_register_driver(&sc16is7xx_uart);
1723 	if (ret) {
1724 		pr_err("Registering UART driver failed\n");
1725 		return ret;
1726 	}
1727 
1728 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1729 	ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
1730 	if (ret < 0) {
1731 		pr_err("failed to init sc16is7xx i2c --> %d\n", ret);
1732 		goto err_i2c;
1733 	}
1734 #endif
1735 
1736 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1737 	ret = spi_register_driver(&sc16is7xx_spi_uart_driver);
1738 	if (ret < 0) {
1739 		pr_err("failed to init sc16is7xx spi --> %d\n", ret);
1740 		goto err_spi;
1741 	}
1742 #endif
1743 	return ret;
1744 
1745 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1746 err_spi:
1747 #endif
1748 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1749 	i2c_del_driver(&sc16is7xx_i2c_uart_driver);
1750 err_i2c:
1751 #endif
1752 	uart_unregister_driver(&sc16is7xx_uart);
1753 	return ret;
1754 }
1755 module_init(sc16is7xx_init);
1756 
1757 static void __exit sc16is7xx_exit(void)
1758 {
1759 #ifdef CONFIG_SERIAL_SC16IS7XX_I2C
1760 	i2c_del_driver(&sc16is7xx_i2c_uart_driver);
1761 #endif
1762 
1763 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
1764 	spi_unregister_driver(&sc16is7xx_spi_uart_driver);
1765 #endif
1766 	uart_unregister_driver(&sc16is7xx_uart);
1767 }
1768 module_exit(sc16is7xx_exit);
1769 
1770 MODULE_LICENSE("GPL");
1771 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1772 MODULE_DESCRIPTION("SC16IS7XX serial driver");
1773