xref: /linux/drivers/tty/serial/sc16is7xx.c (revision 649e980dadee36f961738d054627225542d547a2)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * SC16IS7xx tty serial driver - common code
4  *
5  * Copyright (C) 2014 GridPoint
6  * Author: Jon Ringle <jringle@gridpoint.com>
7  * Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
8  */
9 
10 #undef DEFAULT_SYMBOL_NAMESPACE
11 #define DEFAULT_SYMBOL_NAMESPACE SERIAL_NXP_SC16IS7XX
12 
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/device.h>
16 #include <linux/export.h>
17 #include <linux/gpio/consumer.h>
18 #include <linux/gpio/driver.h>
19 #include <linux/idr.h>
20 #include <linux/kthread.h>
21 #include <linux/mod_devicetable.h>
22 #include <linux/module.h>
23 #include <linux/property.h>
24 #include <linux/regmap.h>
25 #include <linux/sched.h>
26 #include <linux/serial_core.h>
27 #include <linux/serial.h>
28 #include <linux/string.h>
29 #include <linux/tty.h>
30 #include <linux/tty_flip.h>
31 #include <linux/uaccess.h>
32 #include <linux/units.h>
33 
34 #include "sc16is7xx.h"
35 
36 #define SC16IS7XX_MAX_DEVS		8
37 
38 /* SC16IS7XX register definitions */
39 #define SC16IS7XX_RHR_REG		(0x00) /* RX FIFO */
40 #define SC16IS7XX_THR_REG		(0x00) /* TX FIFO */
41 #define SC16IS7XX_IER_REG		(0x01) /* Interrupt enable */
42 #define SC16IS7XX_IIR_REG		(0x02) /* Interrupt Identification */
43 #define SC16IS7XX_FCR_REG		(0x02) /* FIFO control */
44 #define SC16IS7XX_LCR_REG		(0x03) /* Line Control */
45 #define SC16IS7XX_MCR_REG		(0x04) /* Modem Control */
46 #define SC16IS7XX_LSR_REG		(0x05) /* Line Status */
47 #define SC16IS7XX_MSR_REG		(0x06) /* Modem Status */
48 #define SC16IS7XX_SPR_REG		(0x07) /* Scratch Pad */
49 #define SC16IS7XX_TXLVL_REG		(0x08) /* TX FIFO level */
50 #define SC16IS7XX_RXLVL_REG		(0x09) /* RX FIFO level */
51 #define SC16IS7XX_IODIR_REG		(0x0a) /* I/O Direction
52 						* - only on 75x/76x
53 						*/
54 #define SC16IS7XX_IOSTATE_REG		(0x0b) /* I/O State
55 						* - only on 75x/76x
56 						*/
57 #define SC16IS7XX_IOINTENA_REG		(0x0c) /* I/O Interrupt Enable
58 						* - only on 75x/76x
59 						*/
60 #define SC16IS7XX_IOCONTROL_REG		(0x0e) /* I/O Control
61 						* - only on 75x/76x
62 						*/
63 #define SC16IS7XX_EFCR_REG		(0x0f) /* Extra Features Control */
64 
65 /* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
66 #define SC16IS7XX_TCR_REG		(0x06) /* Transmit control */
67 #define SC16IS7XX_TLR_REG		(0x07) /* Trigger level */
68 
69 /* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
70 #define SC16IS7XX_DLL_REG		(0x00) /* Divisor Latch Low */
71 #define SC16IS7XX_DLH_REG		(0x01) /* Divisor Latch High */
72 
73 /* Enhanced Register set: Only if (LCR == 0xBF) */
74 #define SC16IS7XX_EFR_REG		(0x02) /* Enhanced Features */
75 #define SC16IS7XX_XON1_REG		(0x04) /* Xon1 word */
76 #define SC16IS7XX_XON2_REG		(0x05) /* Xon2 word */
77 #define SC16IS7XX_XOFF1_REG		(0x06) /* Xoff1 word */
78 #define SC16IS7XX_XOFF2_REG		(0x07) /* Xoff2 word */
79 
80 /* IER register bits */
81 #define SC16IS7XX_IER_RDI_BIT		(1 << 0) /* Enable RX data interrupt */
82 #define SC16IS7XX_IER_THRI_BIT		(1 << 1) /* Enable TX holding register
83 						  * interrupt */
84 #define SC16IS7XX_IER_RLSI_BIT		(1 << 2) /* Enable RX line status
85 						  * interrupt */
86 #define SC16IS7XX_IER_MSI_BIT		(1 << 3) /* Enable Modem status
87 						  * interrupt */
88 
89 /* IER register bits - write only if (EFR[4] == 1) */
90 #define SC16IS7XX_IER_SLEEP_BIT		(1 << 4) /* Enable Sleep mode */
91 #define SC16IS7XX_IER_XOFFI_BIT		(1 << 5) /* Enable Xoff interrupt */
92 #define SC16IS7XX_IER_RTSI_BIT		(1 << 6) /* Enable nRTS interrupt */
93 #define SC16IS7XX_IER_CTSI_BIT		(1 << 7) /* Enable nCTS interrupt */
94 
95 /* FCR register bits */
96 #define SC16IS7XX_FCR_FIFO_BIT		(1 << 0) /* Enable FIFO */
97 #define SC16IS7XX_FCR_RXRESET_BIT	(1 << 1) /* Reset RX FIFO */
98 #define SC16IS7XX_FCR_TXRESET_BIT	(1 << 2) /* Reset TX FIFO */
99 #define SC16IS7XX_FCR_RXLVLL_BIT	(1 << 6) /* RX Trigger level LSB */
100 #define SC16IS7XX_FCR_RXLVLH_BIT	(1 << 7) /* RX Trigger level MSB */
101 
102 /* FCR register bits - write only if (EFR[4] == 1) */
103 #define SC16IS7XX_FCR_TXLVLL_BIT	(1 << 4) /* TX Trigger level LSB */
104 #define SC16IS7XX_FCR_TXLVLH_BIT	(1 << 5) /* TX Trigger level MSB */
105 
106 /* IIR register bits */
107 #define SC16IS7XX_IIR_NO_INT_BIT	(1 << 0) /* No interrupts pending */
108 #define SC16IS7XX_IIR_ID_MASK		0x3e     /* Mask for the interrupt ID */
109 #define SC16IS7XX_IIR_THRI_SRC		0x02     /* TX holding register empty */
110 #define SC16IS7XX_IIR_RDI_SRC		0x04     /* RX data interrupt */
111 #define SC16IS7XX_IIR_RLSE_SRC		0x06     /* RX line status error */
112 #define SC16IS7XX_IIR_RTOI_SRC		0x0c     /* RX time-out interrupt */
113 #define SC16IS7XX_IIR_MSI_SRC		0x00     /* Modem status interrupt
114 						  * - only on 75x/76x
115 						  */
116 #define SC16IS7XX_IIR_INPIN_SRC		0x30     /* Input pin change of state
117 						  * - only on 75x/76x
118 						  */
119 #define SC16IS7XX_IIR_XOFFI_SRC		0x10     /* Received Xoff */
120 #define SC16IS7XX_IIR_CTSRTS_SRC	0x20     /* nCTS,nRTS change of state
121 						  * from active (LOW)
122 						  * to inactive (HIGH)
123 						  */
124 /* LCR register bits */
125 #define SC16IS7XX_LCR_LENGTH0_BIT	(1 << 0) /* Word length bit 0 */
126 #define SC16IS7XX_LCR_LENGTH1_BIT	(1 << 1) /* Word length bit 1
127 						  *
128 						  * Word length bits table:
129 						  * 00 -> 5 bit words
130 						  * 01 -> 6 bit words
131 						  * 10 -> 7 bit words
132 						  * 11 -> 8 bit words
133 						  */
134 #define SC16IS7XX_LCR_STOPLEN_BIT	(1 << 2) /* STOP length bit
135 						  *
136 						  * STOP length bit table:
137 						  * 0 -> 1 stop bit
138 						  * 1 -> 1-1.5 stop bits if
139 						  *      word length is 5,
140 						  *      2 stop bits otherwise
141 						  */
142 #define SC16IS7XX_LCR_PARITY_BIT	(1 << 3) /* Parity bit enable */
143 #define SC16IS7XX_LCR_EVENPARITY_BIT	(1 << 4) /* Even parity bit enable */
144 #define SC16IS7XX_LCR_FORCEPARITY_BIT	(1 << 5) /* 9-bit multidrop parity */
145 #define SC16IS7XX_LCR_TXBREAK_BIT	(1 << 6) /* TX break enable */
146 #define SC16IS7XX_LCR_DLAB_BIT		(1 << 7) /* Divisor Latch enable */
147 #define SC16IS7XX_LCR_WORD_LEN_5	(0x00)
148 #define SC16IS7XX_LCR_WORD_LEN_6	(0x01)
149 #define SC16IS7XX_LCR_WORD_LEN_7	(0x02)
150 #define SC16IS7XX_LCR_WORD_LEN_8	(0x03)
151 #define SC16IS7XX_LCR_CONF_MODE_A	SC16IS7XX_LCR_DLAB_BIT /* Special
152 								* reg set */
153 #define SC16IS7XX_LCR_CONF_MODE_B	0xBF                   /* Enhanced
154 								* reg set */
155 
156 /* MCR register bits */
157 #define SC16IS7XX_MCR_DTR_BIT		(1 << 0) /* DTR complement
158 						  * - only on 75x/76x
159 						  */
160 #define SC16IS7XX_MCR_RTS_BIT		(1 << 1) /* RTS complement */
161 #define SC16IS7XX_MCR_TCRTLR_BIT	(1 << 2) /* TCR/TLR register enable */
162 #define SC16IS7XX_MCR_LOOP_BIT		(1 << 4) /* Enable loopback test mode */
163 #define SC16IS7XX_MCR_XONANY_BIT	(1 << 5) /* Enable Xon Any
164 						  * - write enabled
165 						  * if (EFR[4] == 1)
166 						  */
167 #define SC16IS7XX_MCR_IRDA_BIT		(1 << 6) /* Enable IrDA mode
168 						  * - write enabled
169 						  * if (EFR[4] == 1)
170 						  */
171 #define SC16IS7XX_MCR_CLKSEL_BIT	(1 << 7) /* Divide clock by 4
172 						  * - write enabled
173 						  * if (EFR[4] == 1)
174 						  */
175 
176 /* LSR register bits */
177 #define SC16IS7XX_LSR_DR_BIT		(1 << 0) /* Receiver data ready */
178 #define SC16IS7XX_LSR_OE_BIT		(1 << 1) /* Overrun Error */
179 #define SC16IS7XX_LSR_PE_BIT		(1 << 2) /* Parity Error */
180 #define SC16IS7XX_LSR_FE_BIT		(1 << 3) /* Frame Error */
181 #define SC16IS7XX_LSR_BI_BIT		(1 << 4) /* Break Interrupt */
182 #define SC16IS7XX_LSR_BRK_ERROR_MASK	0x1E     /* BI, FE, PE, OE bits */
183 #define SC16IS7XX_LSR_THRE_BIT		(1 << 5) /* TX holding register empty */
184 #define SC16IS7XX_LSR_TEMT_BIT		(1 << 6) /* Transmitter empty */
185 #define SC16IS7XX_LSR_FIFOE_BIT		(1 << 7) /* Fifo Error */
186 
187 /* MSR register bits */
188 #define SC16IS7XX_MSR_DCTS_BIT		(1 << 0) /* Delta CTS Clear To Send */
189 #define SC16IS7XX_MSR_DDSR_BIT		(1 << 1) /* Delta DSR Data Set Ready
190 						  * or (IO4)
191 						  * - only on 75x/76x
192 						  */
193 #define SC16IS7XX_MSR_DRI_BIT		(1 << 2) /* Delta RI Ring Indicator
194 						  * or (IO7)
195 						  * - only on 75x/76x
196 						  */
197 #define SC16IS7XX_MSR_DCD_BIT		(1 << 3) /* Delta CD Carrier Detect
198 						  * or (IO6)
199 						  * - only on 75x/76x
200 						  */
201 #define SC16IS7XX_MSR_CTS_BIT		(1 << 4) /* CTS */
202 #define SC16IS7XX_MSR_DSR_BIT		(1 << 5) /* DSR (IO4)
203 						  * - only on 75x/76x
204 						  */
205 #define SC16IS7XX_MSR_RI_BIT		(1 << 6) /* RI (IO7)
206 						  * - only on 75x/76x
207 						  */
208 #define SC16IS7XX_MSR_CD_BIT		(1 << 7) /* CD (IO6)
209 						  * - only on 75x/76x
210 						  */
211 #define SC16IS7XX_MSR_DELTA_MASK	0x0F     /* Any of the delta bits! */
212 
213 /*
214  * TCR register bits
215  * TCR trigger levels are available from 0 to 60 characters with a granularity
216  * of four.
217  * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
218  * no built-in hardware check to make sure this condition is met. Also, the TCR
219  * must be programmed with this condition before auto RTS or software flow
220  * control is enabled to avoid spurious operation of the device.
221  */
222 #define SC16IS7XX_TCR_RX_HALT(words)	((((words) / 4) & 0x0f) << 0)
223 #define SC16IS7XX_TCR_RX_RESUME(words)	((((words) / 4) & 0x0f) << 4)
224 
225 /*
226  * TLR register bits
227  * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
228  * FIFO Control Register (FCR) are used for the transmit and receive FIFO
229  * trigger levels. Trigger levels from 4 characters to 60 characters are
230  * available with a granularity of four.
231  *
232  * When the trigger level setting in TLR is zero, the SC16IS74x/75x/76x uses the
233  * trigger level setting defined in FCR. If TLR has non-zero trigger level value
234  * the trigger level defined in FCR is discarded. This applies to both transmit
235  * FIFO and receive FIFO trigger level setting.
236  *
237  * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
238  * default state, that is, '00'.
239  */
240 #define SC16IS7XX_TLR_TX_TRIGGER(words)	((((words) / 4) & 0x0f) << 0)
241 #define SC16IS7XX_TLR_RX_TRIGGER(words)	((((words) / 4) & 0x0f) << 4)
242 
243 /* IOControl register bits (Only 75x/76x) */
244 #define SC16IS7XX_IOCONTROL_LATCH_BIT	(1 << 0) /* Enable input latching */
245 #define SC16IS7XX_IOCONTROL_MODEM_A_BIT	(1 << 1) /* Enable GPIO[7:4] as modem A pins */
246 #define SC16IS7XX_IOCONTROL_MODEM_B_BIT	(1 << 2) /* Enable GPIO[3:0] as modem B pins */
247 #define SC16IS7XX_IOCONTROL_SRESET_BIT	(1 << 3) /* Software Reset */
248 
249 /* EFCR register bits */
250 #define SC16IS7XX_EFCR_9BIT_MODE_BIT	(1 << 0) /* Enable 9-bit or Multidrop
251 						  * mode (RS485) */
252 #define SC16IS7XX_EFCR_RXDISABLE_BIT	(1 << 1) /* Disable receiver */
253 #define SC16IS7XX_EFCR_TXDISABLE_BIT	(1 << 2) /* Disable transmitter */
254 #define SC16IS7XX_EFCR_AUTO_RS485_BIT	(1 << 4) /* Auto RS485 RTS direction */
255 #define SC16IS7XX_EFCR_RTS_INVERT_BIT	(1 << 5) /* RTS output inversion */
256 #define SC16IS7XX_EFCR_IRDA_MODE_BIT	(1 << 7) /* IrDA mode
257 						  * 0 = rate upto 115.2 kbit/s
258 						  *   - Only 75x/76x
259 						  * 1 = rate upto 1.152 Mbit/s
260 						  *   - Only 76x
261 						  */
262 
263 /* EFR register bits */
264 #define SC16IS7XX_EFR_AUTORTS_BIT	(1 << 6) /* Auto RTS flow ctrl enable */
265 #define SC16IS7XX_EFR_AUTOCTS_BIT	(1 << 7) /* Auto CTS flow ctrl enable */
266 #define SC16IS7XX_EFR_XOFF2_DETECT_BIT	(1 << 5) /* Enable Xoff2 detection */
267 #define SC16IS7XX_EFR_ENABLE_BIT	(1 << 4) /* Enable enhanced functions
268 						  * and writing to IER[7:4],
269 						  * FCR[5:4], MCR[7:5]
270 						  */
271 #define SC16IS7XX_EFR_SWFLOW3_BIT	(1 << 3) /* SWFLOW bit 3 */
272 #define SC16IS7XX_EFR_SWFLOW2_BIT	(1 << 2) /* SWFLOW bit 2
273 						  *
274 						  * SWFLOW bits 3 & 2 table:
275 						  * 00 -> no transmitter flow
276 						  *       control
277 						  * 01 -> transmitter generates
278 						  *       XON2 and XOFF2
279 						  * 10 -> transmitter generates
280 						  *       XON1 and XOFF1
281 						  * 11 -> transmitter generates
282 						  *       XON1, XON2, XOFF1 and
283 						  *       XOFF2
284 						  */
285 #define SC16IS7XX_EFR_SWFLOW1_BIT	(1 << 1) /* SWFLOW bit 2 */
286 #define SC16IS7XX_EFR_SWFLOW0_BIT	(1 << 0) /* SWFLOW bit 3
287 						  *
288 						  * SWFLOW bits 3 & 2 table:
289 						  * 00 -> no received flow
290 						  *       control
291 						  * 01 -> receiver compares
292 						  *       XON2 and XOFF2
293 						  * 10 -> receiver compares
294 						  *       XON1 and XOFF1
295 						  * 11 -> receiver compares
296 						  *       XON1, XON2, XOFF1 and
297 						  *       XOFF2
298 						  */
299 #define SC16IS7XX_EFR_FLOWCTRL_BITS	(SC16IS7XX_EFR_AUTORTS_BIT | \
300 					SC16IS7XX_EFR_AUTOCTS_BIT | \
301 					SC16IS7XX_EFR_XOFF2_DETECT_BIT | \
302 					SC16IS7XX_EFR_SWFLOW3_BIT | \
303 					SC16IS7XX_EFR_SWFLOW2_BIT | \
304 					SC16IS7XX_EFR_SWFLOW1_BIT | \
305 					SC16IS7XX_EFR_SWFLOW0_BIT)
306 
307 
308 /* Misc definitions */
309 #define SC16IS7XX_FIFO_SIZE		(64)
310 #define SC16IS7XX_GPIOS_PER_BANK	4
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 	struct regmap			*regmap;
325 	struct mutex			efr_lock; /* EFR registers access */
326 	struct kthread_work		tx_work;
327 	struct kthread_work		reg_work;
328 	struct kthread_delayed_work	ms_work;
329 	struct sc16is7xx_one_config	config;
330 	unsigned char			buf[SC16IS7XX_FIFO_SIZE]; /* Rx buffer. */
331 	unsigned int			old_mctrl;
332 	u8				old_lcr; /* Value before EFR access. */
333 	bool				irda_mode;
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 	struct kthread_worker		kworker;
345 	struct task_struct		*kworker_task;
346 	struct sc16is7xx_one		p[];
347 };
348 
349 static DEFINE_IDA(sc16is7xx_lines);
350 
351 static struct uart_driver sc16is7xx_uart = {
352 	.owner		= THIS_MODULE,
353 	.driver_name    = SC16IS7XX_NAME,
354 	.dev_name	= "ttySC",
355 	.nr		= SC16IS7XX_MAX_DEVS,
356 };
357 
358 #define to_sc16is7xx_one(p,e)	((container_of((p), struct sc16is7xx_one, e)))
359 
360 static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
361 {
362 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
363 	unsigned int val = 0;
364 
365 	regmap_read(one->regmap, reg, &val);
366 
367 	return val;
368 }
369 
370 static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
371 {
372 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
373 
374 	regmap_write(one->regmap, reg, val);
375 }
376 
377 static void sc16is7xx_fifo_read(struct uart_port *port, u8 *rxbuf, unsigned int rxlen)
378 {
379 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
380 
381 	regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, rxbuf, rxlen);
382 }
383 
384 static void sc16is7xx_fifo_write(struct uart_port *port, u8 *txbuf, u8 to_send)
385 {
386 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
387 
388 	/*
389 	 * Don't send zero-length data, at least on SPI it confuses the chip
390 	 * delivering wrong TXLVL data.
391 	 */
392 	if (unlikely(!to_send))
393 		return;
394 
395 	regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, txbuf, to_send);
396 }
397 
398 static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
399 				  u8 mask, u8 val)
400 {
401 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
402 
403 	regmap_update_bits(one->regmap, reg, mask, val);
404 }
405 
406 static void sc16is7xx_power(struct uart_port *port, int on)
407 {
408 	sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
409 			      SC16IS7XX_IER_SLEEP_BIT,
410 			      on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
411 }
412 
413 /*
414  * In an amazing feat of design, the Enhanced Features Register (EFR)
415  * shares the address of the Interrupt Identification Register (IIR).
416  * Access to EFR is switched on by writing a magic value (0xbf) to the
417  * Line Control Register (LCR). Any interrupt firing during this time will
418  * see the EFR where it expects the IIR to be, leading to
419  * "Unexpected interrupt" messages.
420  *
421  * Prevent this possibility by claiming a mutex while accessing the EFR,
422  * and claiming the same mutex from within the interrupt handler. This is
423  * similar to disabling the interrupt, but that doesn't work because the
424  * bulk of the interrupt processing is run as a workqueue job in thread
425  * context.
426  */
427 static void sc16is7xx_efr_lock(struct uart_port *port)
428 {
429 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
430 
431 	mutex_lock(&one->efr_lock);
432 
433 	/* Backup content of LCR. */
434 	one->old_lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
435 
436 	/* Enable access to Enhanced register set */
437 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B);
438 
439 	/* Disable cache updates when writing to EFR registers */
440 	regcache_cache_bypass(one->regmap, true);
441 }
442 
443 static void sc16is7xx_efr_unlock(struct uart_port *port)
444 {
445 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
446 
447 	/* Re-enable cache updates when writing to normal registers */
448 	regcache_cache_bypass(one->regmap, false);
449 
450 	/* Restore original content of LCR */
451 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, one->old_lcr);
452 
453 	mutex_unlock(&one->efr_lock);
454 }
455 
456 static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
457 {
458 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
459 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
460 
461 	lockdep_assert_held_once(&port->lock);
462 
463 	one->config.flags |= SC16IS7XX_RECONF_IER;
464 	one->config.ier_mask |= bit;
465 	one->config.ier_val &= ~bit;
466 	kthread_queue_work(&s->kworker, &one->reg_work);
467 }
468 
469 static void sc16is7xx_ier_set(struct uart_port *port, u8 bit)
470 {
471 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
472 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
473 
474 	lockdep_assert_held_once(&port->lock);
475 
476 	one->config.flags |= SC16IS7XX_RECONF_IER;
477 	one->config.ier_mask |= bit;
478 	one->config.ier_val |= bit;
479 	kthread_queue_work(&s->kworker, &one->reg_work);
480 }
481 
482 static void sc16is7xx_stop_tx(struct uart_port *port)
483 {
484 	sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
485 }
486 
487 static void sc16is7xx_stop_rx(struct uart_port *port)
488 {
489 	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
490 }
491 
492 const struct sc16is7xx_devtype sc16is74x_devtype = {
493 	.name		= "SC16IS74X",
494 	.nr_gpio	= 0,
495 	.nr_uart	= 1,
496 };
497 EXPORT_SYMBOL_GPL(sc16is74x_devtype);
498 
499 const struct sc16is7xx_devtype sc16is750_devtype = {
500 	.name		= "SC16IS750",
501 	.nr_gpio	= 8,
502 	.nr_uart	= 1,
503 };
504 EXPORT_SYMBOL_GPL(sc16is750_devtype);
505 
506 const struct sc16is7xx_devtype sc16is752_devtype = {
507 	.name		= "SC16IS752",
508 	.nr_gpio	= 8,
509 	.nr_uart	= 2,
510 };
511 EXPORT_SYMBOL_GPL(sc16is752_devtype);
512 
513 const struct sc16is7xx_devtype sc16is760_devtype = {
514 	.name		= "SC16IS760",
515 	.nr_gpio	= 8,
516 	.nr_uart	= 1,
517 };
518 EXPORT_SYMBOL_GPL(sc16is760_devtype);
519 
520 const struct sc16is7xx_devtype sc16is762_devtype = {
521 	.name		= "SC16IS762",
522 	.nr_gpio	= 8,
523 	.nr_uart	= 2,
524 };
525 EXPORT_SYMBOL_GPL(sc16is762_devtype);
526 
527 static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
528 {
529 	switch (reg) {
530 	case SC16IS7XX_RHR_REG:
531 	case SC16IS7XX_IIR_REG:
532 	case SC16IS7XX_LSR_REG:
533 	case SC16IS7XX_MSR_REG:
534 	case SC16IS7XX_TXLVL_REG:
535 	case SC16IS7XX_RXLVL_REG:
536 	case SC16IS7XX_IOSTATE_REG:
537 	case SC16IS7XX_IOCONTROL_REG:
538 		return true;
539 	default:
540 		return false;
541 	}
542 }
543 
544 static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
545 {
546 	switch (reg) {
547 	case SC16IS7XX_RHR_REG:
548 		return true;
549 	default:
550 		return false;
551 	}
552 }
553 
554 static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
555 {
556 	return reg == SC16IS7XX_RHR_REG;
557 }
558 
559 /*
560  * Configure programmable baud rate generator (divisor) according to the
561  * desired baud rate.
562  *
563  * From the datasheet, the divisor is computed according to:
564  *
565  *              XTAL1 input frequency
566  *             -----------------------
567  *                    prescaler
568  * divisor = ---------------------------
569  *            baud-rate x sampling-rate
570  */
571 static int sc16is7xx_set_baud(struct uart_port *port, int baud)
572 {
573 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
574 	u8 lcr;
575 	unsigned int prescaler = 1;
576 	unsigned long clk = port->uartclk, div = clk / 16 / baud;
577 
578 	if (div >= BIT(16)) {
579 		prescaler = 4;
580 		div /= prescaler;
581 	}
582 
583 	/* Enable enhanced features */
584 	sc16is7xx_efr_lock(port);
585 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
586 			      SC16IS7XX_EFR_ENABLE_BIT,
587 			      SC16IS7XX_EFR_ENABLE_BIT);
588 	sc16is7xx_efr_unlock(port);
589 
590 	/* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */
591 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
592 			      SC16IS7XX_MCR_CLKSEL_BIT,
593 			      prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT);
594 
595 	mutex_lock(&one->efr_lock);
596 
597 	/* Backup LCR and access special register set (DLL/DLH) */
598 	lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
599 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
600 			     SC16IS7XX_LCR_CONF_MODE_A);
601 
602 	/* Write the new divisor */
603 	regcache_cache_bypass(one->regmap, true);
604 	sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
605 	sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
606 	regcache_cache_bypass(one->regmap, false);
607 
608 	/* Restore LCR and access to general register set */
609 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
610 
611 	mutex_unlock(&one->efr_lock);
612 
613 	return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div);
614 }
615 
616 static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
617 				unsigned int iir)
618 {
619 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
620 	unsigned int lsr = 0, bytes_read, i;
621 	bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
622 	u8 ch, flag;
623 
624 	if (unlikely(rxlen >= sizeof(one->buf))) {
625 		dev_warn_ratelimited(port->dev,
626 				     "ttySC%i: Possible RX FIFO overrun: %d\n",
627 				     port->line, rxlen);
628 		port->icount.buf_overrun++;
629 		/* Ensure sanity of RX level */
630 		rxlen = sizeof(one->buf);
631 	}
632 
633 	while (rxlen) {
634 		/* Only read lsr if there are possible errors in FIFO */
635 		if (read_lsr) {
636 			lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
637 			if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
638 				read_lsr = false; /* No errors left in FIFO */
639 		} else
640 			lsr = 0;
641 
642 		if (read_lsr) {
643 			one->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
644 			bytes_read = 1;
645 		} else {
646 			sc16is7xx_fifo_read(port, one->buf, rxlen);
647 			bytes_read = rxlen;
648 		}
649 
650 		lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
651 
652 		port->icount.rx++;
653 		flag = TTY_NORMAL;
654 
655 		if (unlikely(lsr)) {
656 			if (lsr & SC16IS7XX_LSR_BI_BIT) {
657 				port->icount.brk++;
658 				if (uart_handle_break(port))
659 					continue;
660 			} else if (lsr & SC16IS7XX_LSR_PE_BIT)
661 				port->icount.parity++;
662 			else if (lsr & SC16IS7XX_LSR_FE_BIT)
663 				port->icount.frame++;
664 			else if (lsr & SC16IS7XX_LSR_OE_BIT)
665 				port->icount.overrun++;
666 
667 			lsr &= port->read_status_mask;
668 			if (lsr & SC16IS7XX_LSR_BI_BIT)
669 				flag = TTY_BREAK;
670 			else if (lsr & SC16IS7XX_LSR_PE_BIT)
671 				flag = TTY_PARITY;
672 			else if (lsr & SC16IS7XX_LSR_FE_BIT)
673 				flag = TTY_FRAME;
674 			else if (lsr & SC16IS7XX_LSR_OE_BIT)
675 				flag = TTY_OVERRUN;
676 		}
677 
678 		for (i = 0; i < bytes_read; ++i) {
679 			ch = one->buf[i];
680 			if (uart_handle_sysrq_char(port, ch))
681 				continue;
682 
683 			if (lsr & port->ignore_status_mask)
684 				continue;
685 
686 			uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
687 					 flag);
688 		}
689 		rxlen -= bytes_read;
690 	}
691 
692 	tty_flip_buffer_push(&port->state->port);
693 }
694 
695 static void sc16is7xx_handle_tx(struct uart_port *port)
696 {
697 	struct tty_port *tport = &port->state->port;
698 	unsigned long flags;
699 	unsigned int txlen;
700 	unsigned char *tail;
701 
702 	if (unlikely(port->x_char)) {
703 		sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
704 		port->icount.tx++;
705 		port->x_char = 0;
706 		return;
707 	}
708 
709 	if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) {
710 		uart_port_lock_irqsave(port, &flags);
711 		sc16is7xx_stop_tx(port);
712 		uart_port_unlock_irqrestore(port, flags);
713 		return;
714 	}
715 
716 	/* Limit to space available in TX FIFO */
717 	txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
718 	if (txlen > SC16IS7XX_FIFO_SIZE) {
719 		dev_err_ratelimited(port->dev,
720 			"chip reports %d free bytes in TX fifo, but it only has %d",
721 			txlen, SC16IS7XX_FIFO_SIZE);
722 		txlen = 0;
723 	}
724 
725 	txlen = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail, txlen);
726 	sc16is7xx_fifo_write(port, tail, txlen);
727 	uart_xmit_advance(port, txlen);
728 
729 	uart_port_lock_irqsave(port, &flags);
730 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
731 		uart_write_wakeup(port);
732 
733 	if (kfifo_is_empty(&tport->xmit_fifo))
734 		sc16is7xx_stop_tx(port);
735 	else
736 		sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
737 	uart_port_unlock_irqrestore(port, flags);
738 }
739 
740 static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
741 {
742 	u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
743 	unsigned int mctrl = 0;
744 
745 	mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
746 	mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0;
747 	mctrl |= (msr & SC16IS7XX_MSR_CD_BIT)  ? TIOCM_CAR : 0;
748 	mctrl |= (msr & SC16IS7XX_MSR_RI_BIT)  ? TIOCM_RNG : 0;
749 	return mctrl;
750 }
751 
752 static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
753 {
754 	struct uart_port *port = &one->port;
755 	unsigned long flags;
756 	unsigned int status, changed;
757 
758 	lockdep_assert_held_once(&one->efr_lock);
759 
760 	status = sc16is7xx_get_hwmctrl(port);
761 	changed = status ^ one->old_mctrl;
762 
763 	if (changed == 0)
764 		return;
765 
766 	one->old_mctrl = status;
767 
768 	uart_port_lock_irqsave(port, &flags);
769 	if ((changed & TIOCM_RNG) && (status & TIOCM_RNG))
770 		port->icount.rng++;
771 	if (changed & TIOCM_DSR)
772 		port->icount.dsr++;
773 	if (changed & TIOCM_CAR)
774 		uart_handle_dcd_change(port, status & TIOCM_CAR);
775 	if (changed & TIOCM_CTS)
776 		uart_handle_cts_change(port, status & TIOCM_CTS);
777 
778 	wake_up_interruptible(&port->state->port.delta_msr_wait);
779 	uart_port_unlock_irqrestore(port, flags);
780 }
781 
782 static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
783 {
784 	bool rc = true;
785 	unsigned int iir, rxlen;
786 	struct uart_port *port = &s->p[portno].port;
787 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
788 
789 	mutex_lock(&one->efr_lock);
790 
791 	iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
792 	if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
793 		rc = false;
794 		goto out_port_irq;
795 	}
796 
797 	iir &= SC16IS7XX_IIR_ID_MASK;
798 
799 	switch (iir) {
800 	case SC16IS7XX_IIR_RDI_SRC:
801 	case SC16IS7XX_IIR_RLSE_SRC:
802 	case SC16IS7XX_IIR_RTOI_SRC:
803 	case SC16IS7XX_IIR_XOFFI_SRC:
804 		rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
805 
806 		/*
807 		 * There is a silicon bug that makes the chip report a
808 		 * time-out interrupt but no data in the FIFO. This is
809 		 * described in errata section 18.1.4.
810 		 *
811 		 * When this happens, read one byte from the FIFO to
812 		 * clear the interrupt.
813 		 */
814 		if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen)
815 			rxlen = 1;
816 
817 		if (rxlen)
818 			sc16is7xx_handle_rx(port, rxlen, iir);
819 		break;
820 		/* CTSRTS interrupt comes only when CTS goes inactive */
821 	case SC16IS7XX_IIR_CTSRTS_SRC:
822 	case SC16IS7XX_IIR_MSI_SRC:
823 		sc16is7xx_update_mlines(one);
824 		break;
825 	case SC16IS7XX_IIR_THRI_SRC:
826 		sc16is7xx_handle_tx(port);
827 		break;
828 	default:
829 		dev_err_ratelimited(port->dev,
830 				    "ttySC%i: Unexpected interrupt: %x",
831 				    port->line, iir);
832 		break;
833 	}
834 
835 out_port_irq:
836 	mutex_unlock(&one->efr_lock);
837 
838 	return rc;
839 }
840 
841 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
842 {
843 	bool keep_polling;
844 
845 	struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
846 
847 	do {
848 		int i;
849 
850 		keep_polling = false;
851 
852 		for (i = 0; i < s->devtype->nr_uart; ++i)
853 			keep_polling |= sc16is7xx_port_irq(s, i);
854 	} while (keep_polling);
855 
856 	return IRQ_HANDLED;
857 }
858 
859 static void sc16is7xx_tx_proc(struct kthread_work *ws)
860 {
861 	struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
862 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
863 
864 	if ((port->rs485.flags & SER_RS485_ENABLED) &&
865 	    (port->rs485.delay_rts_before_send > 0))
866 		msleep(port->rs485.delay_rts_before_send);
867 
868 	mutex_lock(&one->efr_lock);
869 	sc16is7xx_handle_tx(port);
870 	mutex_unlock(&one->efr_lock);
871 }
872 
873 static void sc16is7xx_reconf_rs485(struct uart_port *port)
874 {
875 	const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
876 			 SC16IS7XX_EFCR_RTS_INVERT_BIT;
877 	u32 efcr = 0;
878 	struct serial_rs485 *rs485 = &port->rs485;
879 	unsigned long irqflags;
880 
881 	uart_port_lock_irqsave(port, &irqflags);
882 	if (rs485->flags & SER_RS485_ENABLED) {
883 		efcr |=	SC16IS7XX_EFCR_AUTO_RS485_BIT;
884 
885 		if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
886 			efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
887 	}
888 	uart_port_unlock_irqrestore(port, irqflags);
889 
890 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
891 }
892 
893 static void sc16is7xx_reg_proc(struct kthread_work *ws)
894 {
895 	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
896 	struct sc16is7xx_one_config config;
897 	unsigned long irqflags;
898 
899 	uart_port_lock_irqsave(&one->port, &irqflags);
900 	config = one->config;
901 	memset(&one->config, 0, sizeof(one->config));
902 	uart_port_unlock_irqrestore(&one->port, irqflags);
903 
904 	if (config.flags & SC16IS7XX_RECONF_MD) {
905 		u8 mcr = 0;
906 
907 		/* Device ignores RTS setting when hardware flow is enabled */
908 		if (one->port.mctrl & TIOCM_RTS)
909 			mcr |= SC16IS7XX_MCR_RTS_BIT;
910 
911 		if (one->port.mctrl & TIOCM_DTR)
912 			mcr |= SC16IS7XX_MCR_DTR_BIT;
913 
914 		if (one->port.mctrl & TIOCM_LOOP)
915 			mcr |= SC16IS7XX_MCR_LOOP_BIT;
916 		sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
917 				      SC16IS7XX_MCR_RTS_BIT |
918 				      SC16IS7XX_MCR_DTR_BIT |
919 				      SC16IS7XX_MCR_LOOP_BIT,
920 				      mcr);
921 	}
922 
923 	if (config.flags & SC16IS7XX_RECONF_IER)
924 		sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
925 				      config.ier_mask, config.ier_val);
926 
927 	if (config.flags & SC16IS7XX_RECONF_RS485)
928 		sc16is7xx_reconf_rs485(&one->port);
929 }
930 
931 static void sc16is7xx_ms_proc(struct kthread_work *ws)
932 {
933 	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work);
934 	struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
935 
936 	if (one->port.state) {
937 		mutex_lock(&one->efr_lock);
938 		sc16is7xx_update_mlines(one);
939 		mutex_unlock(&one->efr_lock);
940 
941 		kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
942 	}
943 }
944 
945 static void sc16is7xx_enable_ms(struct uart_port *port)
946 {
947 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
948 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
949 
950 	lockdep_assert_held_once(&port->lock);
951 
952 	kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0);
953 }
954 
955 static void sc16is7xx_start_tx(struct uart_port *port)
956 {
957 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
958 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
959 
960 	kthread_queue_work(&s->kworker, &one->tx_work);
961 }
962 
963 static void sc16is7xx_throttle(struct uart_port *port)
964 {
965 	unsigned long flags;
966 
967 	/*
968 	 * Hardware flow control is enabled and thus the device ignores RTS
969 	 * value set in MCR register. Stop reading data from RX FIFO so the
970 	 * AutoRTS feature will de-activate RTS output.
971 	 */
972 	uart_port_lock_irqsave(port, &flags);
973 	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
974 	uart_port_unlock_irqrestore(port, flags);
975 }
976 
977 static void sc16is7xx_unthrottle(struct uart_port *port)
978 {
979 	unsigned long flags;
980 
981 	uart_port_lock_irqsave(port, &flags);
982 	sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT);
983 	uart_port_unlock_irqrestore(port, flags);
984 }
985 
986 static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
987 {
988 	unsigned int lsr;
989 
990 	lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
991 
992 	return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
993 }
994 
995 static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
996 {
997 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
998 
999 	/* Called with port lock taken so we can only return cached value */
1000 	return one->old_mctrl;
1001 }
1002 
1003 static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
1004 {
1005 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1006 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1007 
1008 	one->config.flags |= SC16IS7XX_RECONF_MD;
1009 	kthread_queue_work(&s->kworker, &one->reg_work);
1010 }
1011 
1012 static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
1013 {
1014 	sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
1015 			      SC16IS7XX_LCR_TXBREAK_BIT,
1016 			      break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
1017 }
1018 
1019 static void sc16is7xx_set_termios(struct uart_port *port,
1020 				  struct ktermios *termios,
1021 				  const struct ktermios *old)
1022 {
1023 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1024 	unsigned int lcr, flow = 0;
1025 	int baud;
1026 	unsigned long flags;
1027 
1028 	kthread_cancel_delayed_work_sync(&one->ms_work);
1029 
1030 	/* Mask termios capabilities we don't support */
1031 	termios->c_cflag &= ~CMSPAR;
1032 
1033 	/* Word size */
1034 	switch (termios->c_cflag & CSIZE) {
1035 	case CS5:
1036 		lcr = SC16IS7XX_LCR_WORD_LEN_5;
1037 		break;
1038 	case CS6:
1039 		lcr = SC16IS7XX_LCR_WORD_LEN_6;
1040 		break;
1041 	case CS7:
1042 		lcr = SC16IS7XX_LCR_WORD_LEN_7;
1043 		break;
1044 	case CS8:
1045 		lcr = SC16IS7XX_LCR_WORD_LEN_8;
1046 		break;
1047 	default:
1048 		lcr = SC16IS7XX_LCR_WORD_LEN_8;
1049 		termios->c_cflag &= ~CSIZE;
1050 		termios->c_cflag |= CS8;
1051 		break;
1052 	}
1053 
1054 	/* Parity */
1055 	if (termios->c_cflag & PARENB) {
1056 		lcr |= SC16IS7XX_LCR_PARITY_BIT;
1057 		if (!(termios->c_cflag & PARODD))
1058 			lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
1059 	}
1060 
1061 	/* Stop bits */
1062 	if (termios->c_cflag & CSTOPB)
1063 		lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
1064 
1065 	/* Set read status mask */
1066 	port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
1067 	if (termios->c_iflag & INPCK)
1068 		port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
1069 					  SC16IS7XX_LSR_FE_BIT;
1070 	if (termios->c_iflag & (BRKINT | PARMRK))
1071 		port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
1072 
1073 	/* Set status ignore mask */
1074 	port->ignore_status_mask = 0;
1075 	if (termios->c_iflag & IGNBRK)
1076 		port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
1077 	if (!(termios->c_cflag & CREAD))
1078 		port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
1079 
1080 	/* Configure flow control */
1081 	port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
1082 	if (termios->c_cflag & CRTSCTS) {
1083 		flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
1084 			SC16IS7XX_EFR_AUTORTS_BIT;
1085 		port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1086 	}
1087 	if (termios->c_iflag & IXON)
1088 		flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
1089 	if (termios->c_iflag & IXOFF)
1090 		flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
1091 
1092 	/* Update LCR register */
1093 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
1094 
1095 	/* Update EFR registers */
1096 	sc16is7xx_efr_lock(port);
1097 	sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
1098 	sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
1099 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1100 			      SC16IS7XX_EFR_FLOWCTRL_BITS, flow);
1101 	sc16is7xx_efr_unlock(port);
1102 
1103 	/* Get baud rate generator configuration */
1104 	baud = uart_get_baud_rate(port, termios, old,
1105 				  port->uartclk / 16 / 4 / 0xffff,
1106 				  port->uartclk / 16);
1107 
1108 	/* Setup baudrate generator */
1109 	baud = sc16is7xx_set_baud(port, baud);
1110 
1111 	uart_port_lock_irqsave(port, &flags);
1112 
1113 	/* Update timeout according to new baud rate */
1114 	uart_update_timeout(port, termios->c_cflag, baud);
1115 
1116 	if (UART_ENABLE_MS(port, termios->c_cflag))
1117 		sc16is7xx_enable_ms(port);
1118 
1119 	uart_port_unlock_irqrestore(port, flags);
1120 }
1121 
1122 static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios,
1123 				  struct serial_rs485 *rs485)
1124 {
1125 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1126 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1127 
1128 	if (rs485->flags & SER_RS485_ENABLED) {
1129 		/*
1130 		 * RTS signal is handled by HW, it's timing can't be influenced.
1131 		 * However, it's sometimes useful to delay TX even without RTS
1132 		 * control therefore we try to handle .delay_rts_before_send.
1133 		 */
1134 		if (rs485->delay_rts_after_send)
1135 			return -EINVAL;
1136 	}
1137 
1138 	one->config.flags |= SC16IS7XX_RECONF_RS485;
1139 	kthread_queue_work(&s->kworker, &one->reg_work);
1140 
1141 	return 0;
1142 }
1143 
1144 static int sc16is7xx_startup(struct uart_port *port)
1145 {
1146 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1147 	unsigned int val;
1148 	unsigned long flags;
1149 
1150 	sc16is7xx_power(port, 1);
1151 
1152 	/* Reset FIFOs*/
1153 	val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
1154 	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
1155 	udelay(5);
1156 	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
1157 			     SC16IS7XX_FCR_FIFO_BIT);
1158 
1159 	/* Enable EFR */
1160 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
1161 			     SC16IS7XX_LCR_CONF_MODE_B);
1162 
1163 	regcache_cache_bypass(one->regmap, true);
1164 
1165 	/* Enable write access to enhanced features and internal clock div */
1166 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1167 			      SC16IS7XX_EFR_ENABLE_BIT,
1168 			      SC16IS7XX_EFR_ENABLE_BIT);
1169 
1170 	/* Enable TCR/TLR */
1171 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1172 			      SC16IS7XX_MCR_TCRTLR_BIT,
1173 			      SC16IS7XX_MCR_TCRTLR_BIT);
1174 
1175 	/* Configure flow control levels */
1176 	/* Flow control halt level 48, resume level 24 */
1177 	sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
1178 			     SC16IS7XX_TCR_RX_RESUME(24) |
1179 			     SC16IS7XX_TCR_RX_HALT(48));
1180 
1181 	regcache_cache_bypass(one->regmap, false);
1182 
1183 	/* Now, initialize the UART */
1184 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
1185 
1186 	/* Enable IrDA mode if requested in DT */
1187 	/* This bit must be written with LCR[7] = 0 */
1188 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1189 			      SC16IS7XX_MCR_IRDA_BIT,
1190 			      one->irda_mode ?
1191 				SC16IS7XX_MCR_IRDA_BIT : 0);
1192 
1193 	/* Enable the Rx and Tx FIFO */
1194 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1195 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1196 			      SC16IS7XX_EFCR_TXDISABLE_BIT,
1197 			      0);
1198 
1199 	/* Enable RX, CTS change and modem lines interrupts */
1200 	val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT |
1201 	      SC16IS7XX_IER_MSI_BIT;
1202 	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1203 
1204 	/* Enable modem status polling */
1205 	uart_port_lock_irqsave(port, &flags);
1206 	sc16is7xx_enable_ms(port);
1207 	uart_port_unlock_irqrestore(port, flags);
1208 
1209 	return 0;
1210 }
1211 
1212 static void sc16is7xx_shutdown(struct uart_port *port)
1213 {
1214 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1215 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1216 
1217 	kthread_cancel_delayed_work_sync(&one->ms_work);
1218 
1219 	/* Disable all interrupts */
1220 	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1221 	/* Disable TX/RX */
1222 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1223 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1224 			      SC16IS7XX_EFCR_TXDISABLE_BIT,
1225 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1226 			      SC16IS7XX_EFCR_TXDISABLE_BIT);
1227 
1228 	sc16is7xx_power(port, 0);
1229 
1230 	kthread_flush_worker(&s->kworker);
1231 }
1232 
1233 static const char *sc16is7xx_type(struct uart_port *port)
1234 {
1235 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1236 
1237 	return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1238 }
1239 
1240 static int sc16is7xx_request_port(struct uart_port *port)
1241 {
1242 	/* Do nothing */
1243 	return 0;
1244 }
1245 
1246 static void sc16is7xx_config_port(struct uart_port *port, int flags)
1247 {
1248 	if (flags & UART_CONFIG_TYPE)
1249 		port->type = PORT_SC16IS7XX;
1250 }
1251 
1252 static int sc16is7xx_verify_port(struct uart_port *port,
1253 				 struct serial_struct *s)
1254 {
1255 	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1256 		return -EINVAL;
1257 	if (s->irq != port->irq)
1258 		return -EINVAL;
1259 
1260 	return 0;
1261 }
1262 
1263 static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1264 			 unsigned int oldstate)
1265 {
1266 	sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1267 }
1268 
1269 static void sc16is7xx_null_void(struct uart_port *port)
1270 {
1271 	/* Do nothing */
1272 }
1273 
1274 static const struct uart_ops sc16is7xx_ops = {
1275 	.tx_empty	= sc16is7xx_tx_empty,
1276 	.set_mctrl	= sc16is7xx_set_mctrl,
1277 	.get_mctrl	= sc16is7xx_get_mctrl,
1278 	.stop_tx	= sc16is7xx_stop_tx,
1279 	.start_tx	= sc16is7xx_start_tx,
1280 	.throttle	= sc16is7xx_throttle,
1281 	.unthrottle	= sc16is7xx_unthrottle,
1282 	.stop_rx	= sc16is7xx_stop_rx,
1283 	.enable_ms	= sc16is7xx_enable_ms,
1284 	.break_ctl	= sc16is7xx_break_ctl,
1285 	.startup	= sc16is7xx_startup,
1286 	.shutdown	= sc16is7xx_shutdown,
1287 	.set_termios	= sc16is7xx_set_termios,
1288 	.type		= sc16is7xx_type,
1289 	.request_port	= sc16is7xx_request_port,
1290 	.release_port	= sc16is7xx_null_void,
1291 	.config_port	= sc16is7xx_config_port,
1292 	.verify_port	= sc16is7xx_verify_port,
1293 	.pm		= sc16is7xx_pm,
1294 };
1295 
1296 #ifdef CONFIG_GPIOLIB
1297 static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1298 {
1299 	unsigned int val;
1300 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1301 	struct uart_port *port = &s->p[0].port;
1302 
1303 	val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1304 
1305 	return !!(val & BIT(offset));
1306 }
1307 
1308 static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1309 {
1310 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1311 	struct uart_port *port = &s->p[0].port;
1312 
1313 	sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1314 			      val ? BIT(offset) : 0);
1315 }
1316 
1317 static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1318 					  unsigned offset)
1319 {
1320 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1321 	struct uart_port *port = &s->p[0].port;
1322 
1323 	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1324 
1325 	return 0;
1326 }
1327 
1328 static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1329 					   unsigned offset, int val)
1330 {
1331 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1332 	struct uart_port *port = &s->p[0].port;
1333 	u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1334 
1335 	if (val)
1336 		state |= BIT(offset);
1337 	else
1338 		state &= ~BIT(offset);
1339 
1340 	/*
1341 	 * If we write IOSTATE first, and then IODIR, the output value is not
1342 	 * transferred to the corresponding I/O pin.
1343 	 * The datasheet states that each register bit will be transferred to
1344 	 * the corresponding I/O pin programmed as output when writing to
1345 	 * IOSTATE. Therefore, configure direction first with IODIR, and then
1346 	 * set value after with IOSTATE.
1347 	 */
1348 	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1349 			      BIT(offset));
1350 	sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
1351 
1352 	return 0;
1353 }
1354 
1355 static int sc16is7xx_gpio_init_valid_mask(struct gpio_chip *chip,
1356 					  unsigned long *valid_mask,
1357 					  unsigned int ngpios)
1358 {
1359 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1360 
1361 	*valid_mask = s->gpio_valid_mask;
1362 
1363 	return 0;
1364 }
1365 
1366 static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s)
1367 {
1368 	struct device *dev = s->p[0].port.dev;
1369 
1370 	if (!s->devtype->nr_gpio)
1371 		return 0;
1372 
1373 	switch (s->mctrl_mask) {
1374 	case 0:
1375 		s->gpio_valid_mask = GENMASK(7, 0);
1376 		break;
1377 	case SC16IS7XX_IOCONTROL_MODEM_A_BIT:
1378 		s->gpio_valid_mask = GENMASK(3, 0);
1379 		break;
1380 	case SC16IS7XX_IOCONTROL_MODEM_B_BIT:
1381 		s->gpio_valid_mask = GENMASK(7, 4);
1382 		break;
1383 	default:
1384 		break;
1385 	}
1386 
1387 	if (s->gpio_valid_mask == 0)
1388 		return 0;
1389 
1390 	s->gpio.owner		 = THIS_MODULE;
1391 	s->gpio.parent		 = dev;
1392 	s->gpio.label		 = dev_name(dev);
1393 	s->gpio.init_valid_mask	 = sc16is7xx_gpio_init_valid_mask;
1394 	s->gpio.direction_input	 = sc16is7xx_gpio_direction_input;
1395 	s->gpio.get		 = sc16is7xx_gpio_get;
1396 	s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1397 	s->gpio.set		 = sc16is7xx_gpio_set;
1398 	s->gpio.base		 = -1;
1399 	s->gpio.ngpio		 = s->devtype->nr_gpio;
1400 	s->gpio.can_sleep	 = 1;
1401 
1402 	return gpiochip_add_data(&s->gpio, s);
1403 }
1404 #endif
1405 
1406 static void sc16is7xx_setup_irda_ports(struct sc16is7xx_port *s)
1407 {
1408 	int i;
1409 	int ret;
1410 	int count;
1411 	u32 irda_port[SC16IS7XX_MAX_PORTS];
1412 	struct device *dev = s->p[0].port.dev;
1413 
1414 	count = device_property_count_u32(dev, "irda-mode-ports");
1415 	if (count < 0 || count > ARRAY_SIZE(irda_port))
1416 		return;
1417 
1418 	ret = device_property_read_u32_array(dev, "irda-mode-ports",
1419 					     irda_port, count);
1420 	if (ret)
1421 		return;
1422 
1423 	for (i = 0; i < count; i++) {
1424 		if (irda_port[i] < s->devtype->nr_uart)
1425 			s->p[irda_port[i]].irda_mode = true;
1426 	}
1427 }
1428 
1429 /*
1430  * Configure ports designated to operate as modem control lines.
1431  */
1432 static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
1433 				       struct regmap *regmap)
1434 {
1435 	int i;
1436 	int ret;
1437 	int count;
1438 	u32 mctrl_port[SC16IS7XX_MAX_PORTS];
1439 	struct device *dev = s->p[0].port.dev;
1440 
1441 	count = device_property_count_u32(dev, "nxp,modem-control-line-ports");
1442 	if (count < 0 || count > ARRAY_SIZE(mctrl_port))
1443 		return 0;
1444 
1445 	ret = device_property_read_u32_array(dev, "nxp,modem-control-line-ports",
1446 					     mctrl_port, count);
1447 	if (ret)
1448 		return ret;
1449 
1450 	s->mctrl_mask = 0;
1451 
1452 	for (i = 0; i < count; i++) {
1453 		/* Use GPIO lines as modem control lines */
1454 		if (mctrl_port[i] == 0)
1455 			s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
1456 		else if (mctrl_port[i] == 1)
1457 			s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
1458 	}
1459 
1460 	if (s->mctrl_mask)
1461 		regmap_update_bits(
1462 			regmap,
1463 			SC16IS7XX_IOCONTROL_REG,
1464 			SC16IS7XX_IOCONTROL_MODEM_A_BIT |
1465 			SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask);
1466 
1467 	return 0;
1468 }
1469 
1470 static const struct serial_rs485 sc16is7xx_rs485_supported = {
1471 	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
1472 	.delay_rts_before_send = 1,
1473 	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
1474 };
1475 
1476 /* Reset device, purging any pending irq / data */
1477 static int sc16is7xx_reset(struct device *dev, struct regmap *regmap)
1478 {
1479 	struct gpio_desc *reset_gpio;
1480 
1481 	/* Assert reset GPIO if defined and valid. */
1482 	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
1483 	if (IS_ERR(reset_gpio))
1484 		return dev_err_probe(dev, PTR_ERR(reset_gpio), "Failed to get reset GPIO\n");
1485 
1486 	if (reset_gpio) {
1487 		/* The minimum reset pulse width is 3 us. */
1488 		fsleep(5);
1489 		gpiod_set_value_cansleep(reset_gpio, 0); /* Deassert GPIO */
1490 	} else {
1491 		/* Software reset */
1492 		regmap_write(regmap, SC16IS7XX_IOCONTROL_REG,
1493 			     SC16IS7XX_IOCONTROL_SRESET_BIT);
1494 	}
1495 
1496 	return 0;
1497 }
1498 
1499 int sc16is7xx_probe(struct device *dev, const struct sc16is7xx_devtype *devtype,
1500 		    struct regmap *regmaps[], int irq)
1501 {
1502 	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
1503 	unsigned int val;
1504 	u32 uartclk = 0;
1505 	int i, ret;
1506 	struct sc16is7xx_port *s;
1507 	bool port_registered[SC16IS7XX_MAX_PORTS];
1508 
1509 	for (i = 0; i < devtype->nr_uart; i++)
1510 		if (IS_ERR(regmaps[i]))
1511 			return PTR_ERR(regmaps[i]);
1512 
1513 	/*
1514 	 * This device does not have an identification register that would
1515 	 * tell us if we are really connected to the correct device.
1516 	 * The best we can do is to check if communication is at all possible.
1517 	 *
1518 	 * Note: regmap[0] is used in the probe function to access registers
1519 	 * common to all channels/ports, as it is guaranteed to be present on
1520 	 * all variants.
1521 	 */
1522 	ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val);
1523 	if (ret < 0)
1524 		return -EPROBE_DEFER;
1525 
1526 	/* Alloc port structure */
1527 	s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
1528 	if (!s) {
1529 		dev_err(dev, "Error allocating port structure\n");
1530 		return -ENOMEM;
1531 	}
1532 
1533 	/* Always ask for fixed clock rate from a property. */
1534 	device_property_read_u32(dev, "clock-frequency", &uartclk);
1535 
1536 	s->clk = devm_clk_get_optional(dev, NULL);
1537 	if (IS_ERR(s->clk))
1538 		return PTR_ERR(s->clk);
1539 
1540 	ret = clk_prepare_enable(s->clk);
1541 	if (ret)
1542 		return ret;
1543 
1544 	freq = clk_get_rate(s->clk);
1545 	if (freq == 0) {
1546 		if (uartclk)
1547 			freq = uartclk;
1548 		if (pfreq)
1549 			freq = *pfreq;
1550 		if (freq)
1551 			dev_dbg(dev, "Clock frequency: %luHz\n", freq);
1552 		else
1553 			return -EINVAL;
1554 	}
1555 
1556 	s->devtype = devtype;
1557 	dev_set_drvdata(dev, s);
1558 
1559 	kthread_init_worker(&s->kworker);
1560 	s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1561 				      "sc16is7xx");
1562 	if (IS_ERR(s->kworker_task)) {
1563 		ret = PTR_ERR(s->kworker_task);
1564 		goto out_clk;
1565 	}
1566 	sched_set_fifo(s->kworker_task);
1567 
1568 	ret = sc16is7xx_reset(dev, regmaps[0]);
1569 	if (ret)
1570 		goto out_kthread;
1571 
1572 	/* Mark each port line and status as uninitialised. */
1573 	for (i = 0; i < devtype->nr_uart; ++i) {
1574 		s->p[i].port.line = SC16IS7XX_MAX_DEVS;
1575 		port_registered[i] = false;
1576 	}
1577 
1578 	for (i = 0; i < devtype->nr_uart; ++i) {
1579 		ret = ida_alloc_max(&sc16is7xx_lines,
1580 				    SC16IS7XX_MAX_DEVS - 1, GFP_KERNEL);
1581 		if (ret < 0)
1582 			goto out_ports;
1583 
1584 		s->p[i].port.line = ret;
1585 
1586 		/* Initialize port data */
1587 		s->p[i].port.dev	= dev;
1588 		s->p[i].port.irq	= irq;
1589 		s->p[i].port.type	= PORT_SC16IS7XX;
1590 		s->p[i].port.fifosize	= SC16IS7XX_FIFO_SIZE;
1591 		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1592 		s->p[i].port.iobase	= i;
1593 		/*
1594 		 * Use all ones as membase to make sure uart_configure_port() in
1595 		 * serial_core.c does not abort for SPI/I2C devices where the
1596 		 * membase address is not applicable.
1597 		 */
1598 		s->p[i].port.membase	= (void __iomem *)~0;
1599 		s->p[i].port.iotype	= UPIO_PORT;
1600 		s->p[i].port.uartclk	= freq;
1601 		s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1602 		s->p[i].port.rs485_supported = sc16is7xx_rs485_supported;
1603 		s->p[i].port.ops	= &sc16is7xx_ops;
1604 		s->p[i].old_mctrl	= 0;
1605 		s->p[i].regmap		= regmaps[i];
1606 
1607 		mutex_init(&s->p[i].efr_lock);
1608 
1609 		ret = uart_get_rs485_mode(&s->p[i].port);
1610 		if (ret)
1611 			goto out_ports;
1612 
1613 		/* Disable all interrupts */
1614 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1615 		/* Disable TX/RX */
1616 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1617 				     SC16IS7XX_EFCR_RXDISABLE_BIT |
1618 				     SC16IS7XX_EFCR_TXDISABLE_BIT);
1619 
1620 		/* Initialize kthread work structs */
1621 		kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1622 		kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1623 		kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc);
1624 
1625 		/* Register port */
1626 		ret = uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1627 		if (ret)
1628 			goto out_ports;
1629 
1630 		port_registered[i] = true;
1631 
1632 		/* Enable EFR */
1633 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
1634 				     SC16IS7XX_LCR_CONF_MODE_B);
1635 
1636 		regcache_cache_bypass(regmaps[i], true);
1637 
1638 		/* Enable write access to enhanced features */
1639 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
1640 				     SC16IS7XX_EFR_ENABLE_BIT);
1641 
1642 		regcache_cache_bypass(regmaps[i], false);
1643 
1644 		/* Restore access to general registers */
1645 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
1646 
1647 		/* Go to suspend mode */
1648 		sc16is7xx_power(&s->p[i].port, 0);
1649 	}
1650 
1651 	sc16is7xx_setup_irda_ports(s);
1652 
1653 	ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]);
1654 	if (ret)
1655 		goto out_ports;
1656 
1657 #ifdef CONFIG_GPIOLIB
1658 	ret = sc16is7xx_setup_gpio_chip(s);
1659 	if (ret)
1660 		goto out_ports;
1661 #endif
1662 
1663 	/*
1664 	 * Setup interrupt. We first try to acquire the IRQ line as level IRQ.
1665 	 * If that succeeds, we can allow sharing the interrupt as well.
1666 	 * In case the interrupt controller doesn't support that, we fall
1667 	 * back to a non-shared falling-edge trigger.
1668 	 */
1669 	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1670 					IRQF_TRIGGER_LOW | IRQF_SHARED |
1671 					IRQF_ONESHOT,
1672 					dev_name(dev), s);
1673 	if (!ret)
1674 		return 0;
1675 
1676 	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1677 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1678 					dev_name(dev), s);
1679 	if (!ret)
1680 		return 0;
1681 
1682 #ifdef CONFIG_GPIOLIB
1683 	if (s->gpio_valid_mask)
1684 		gpiochip_remove(&s->gpio);
1685 #endif
1686 
1687 out_ports:
1688 	for (i = 0; i < devtype->nr_uart; i++) {
1689 		if (s->p[i].port.line < SC16IS7XX_MAX_DEVS)
1690 			ida_free(&sc16is7xx_lines, s->p[i].port.line);
1691 		if (port_registered[i])
1692 			uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1693 	}
1694 
1695 out_kthread:
1696 	kthread_stop(s->kworker_task);
1697 
1698 out_clk:
1699 	clk_disable_unprepare(s->clk);
1700 
1701 	return ret;
1702 }
1703 EXPORT_SYMBOL_GPL(sc16is7xx_probe);
1704 
1705 void sc16is7xx_remove(struct device *dev)
1706 {
1707 	struct sc16is7xx_port *s = dev_get_drvdata(dev);
1708 	int i;
1709 
1710 #ifdef CONFIG_GPIOLIB
1711 	if (s->gpio_valid_mask)
1712 		gpiochip_remove(&s->gpio);
1713 #endif
1714 
1715 	for (i = 0; i < s->devtype->nr_uart; i++) {
1716 		kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
1717 		ida_free(&sc16is7xx_lines, s->p[i].port.line);
1718 		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1719 		sc16is7xx_power(&s->p[i].port, 0);
1720 	}
1721 
1722 	kthread_flush_worker(&s->kworker);
1723 	kthread_stop(s->kworker_task);
1724 
1725 	clk_disable_unprepare(s->clk);
1726 }
1727 EXPORT_SYMBOL_GPL(sc16is7xx_remove);
1728 
1729 const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1730 	{ .compatible = "nxp,sc16is740",	.data = &sc16is74x_devtype, },
1731 	{ .compatible = "nxp,sc16is741",	.data = &sc16is74x_devtype, },
1732 	{ .compatible = "nxp,sc16is750",	.data = &sc16is750_devtype, },
1733 	{ .compatible = "nxp,sc16is752",	.data = &sc16is752_devtype, },
1734 	{ .compatible = "nxp,sc16is760",	.data = &sc16is760_devtype, },
1735 	{ .compatible = "nxp,sc16is762",	.data = &sc16is762_devtype, },
1736 	{ }
1737 };
1738 EXPORT_SYMBOL_GPL(sc16is7xx_dt_ids);
1739 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1740 
1741 const struct regmap_config sc16is7xx_regcfg = {
1742 	.reg_bits = 5,
1743 	.pad_bits = 3,
1744 	.val_bits = 8,
1745 	.cache_type = REGCACHE_MAPLE,
1746 	.volatile_reg = sc16is7xx_regmap_volatile,
1747 	.precious_reg = sc16is7xx_regmap_precious,
1748 	.writeable_noinc_reg = sc16is7xx_regmap_noinc,
1749 	.readable_noinc_reg = sc16is7xx_regmap_noinc,
1750 	.max_raw_read = SC16IS7XX_FIFO_SIZE,
1751 	.max_raw_write = SC16IS7XX_FIFO_SIZE,
1752 	.max_register = SC16IS7XX_EFCR_REG,
1753 };
1754 EXPORT_SYMBOL_GPL(sc16is7xx_regcfg);
1755 
1756 const char *sc16is7xx_regmap_name(u8 port_id)
1757 {
1758 	switch (port_id) {
1759 	case 0:	return "port0";
1760 	case 1:	return "port1";
1761 	default:
1762 		WARN_ON(true);
1763 		return NULL;
1764 	}
1765 }
1766 EXPORT_SYMBOL_GPL(sc16is7xx_regmap_name);
1767 
1768 unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
1769 {
1770 	/* CH1,CH0 are at bits 2:1. */
1771 	return port_id << 1;
1772 }
1773 EXPORT_SYMBOL_GPL(sc16is7xx_regmap_port_mask);
1774 
1775 static int __init sc16is7xx_init(void)
1776 {
1777 	return uart_register_driver(&sc16is7xx_uart);
1778 }
1779 module_init(sc16is7xx_init);
1780 
1781 static void __exit sc16is7xx_exit(void)
1782 {
1783 	uart_unregister_driver(&sc16is7xx_uart);
1784 }
1785 module_exit(sc16is7xx_exit);
1786 
1787 MODULE_LICENSE("GPL");
1788 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1789 MODULE_DESCRIPTION("SC16IS7xx tty serial core driver");
1790