xref: /linux/drivers/tty/serial/sc16is7xx.c (revision 0b0e9cdb3d1f8fda823b592b0667b4b0595e2ba7)
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 int			old_mctrl;
331 	u8				old_lcr; /* Value before EFR access. */
332 	bool				irda_mode;
333 };
334 
335 struct sc16is7xx_port {
336 	const struct sc16is7xx_devtype	*devtype;
337 	struct clk			*clk;
338 #ifdef CONFIG_GPIOLIB
339 	struct gpio_chip		gpio;
340 	unsigned long			gpio_valid_mask;
341 #endif
342 	u8				mctrl_mask;
343 	unsigned char			buf[SC16IS7XX_FIFO_SIZE];
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 	/* Backup LCR and access special register set (DLL/DLH) */
596 	lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
597 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
598 			     SC16IS7XX_LCR_CONF_MODE_A);
599 
600 	/* Write the new divisor */
601 	regcache_cache_bypass(one->regmap, true);
602 	sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
603 	sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
604 	regcache_cache_bypass(one->regmap, false);
605 
606 	/* Restore LCR and access to general register set */
607 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
608 
609 	return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div);
610 }
611 
612 static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
613 				unsigned int iir)
614 {
615 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
616 	unsigned int lsr = 0, bytes_read, i;
617 	bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
618 	u8 ch, flag;
619 
620 	if (unlikely(rxlen >= sizeof(s->buf))) {
621 		dev_warn_ratelimited(port->dev,
622 				     "ttySC%i: Possible RX FIFO overrun: %d\n",
623 				     port->line, rxlen);
624 		port->icount.buf_overrun++;
625 		/* Ensure sanity of RX level */
626 		rxlen = sizeof(s->buf);
627 	}
628 
629 	while (rxlen) {
630 		/* Only read lsr if there are possible errors in FIFO */
631 		if (read_lsr) {
632 			lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
633 			if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
634 				read_lsr = false; /* No errors left in FIFO */
635 		} else
636 			lsr = 0;
637 
638 		if (read_lsr) {
639 			s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
640 			bytes_read = 1;
641 		} else {
642 			sc16is7xx_fifo_read(port, s->buf, rxlen);
643 			bytes_read = rxlen;
644 		}
645 
646 		lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
647 
648 		port->icount.rx++;
649 		flag = TTY_NORMAL;
650 
651 		if (unlikely(lsr)) {
652 			if (lsr & SC16IS7XX_LSR_BI_BIT) {
653 				port->icount.brk++;
654 				if (uart_handle_break(port))
655 					continue;
656 			} else if (lsr & SC16IS7XX_LSR_PE_BIT)
657 				port->icount.parity++;
658 			else if (lsr & SC16IS7XX_LSR_FE_BIT)
659 				port->icount.frame++;
660 			else if (lsr & SC16IS7XX_LSR_OE_BIT)
661 				port->icount.overrun++;
662 
663 			lsr &= port->read_status_mask;
664 			if (lsr & SC16IS7XX_LSR_BI_BIT)
665 				flag = TTY_BREAK;
666 			else if (lsr & SC16IS7XX_LSR_PE_BIT)
667 				flag = TTY_PARITY;
668 			else if (lsr & SC16IS7XX_LSR_FE_BIT)
669 				flag = TTY_FRAME;
670 			else if (lsr & SC16IS7XX_LSR_OE_BIT)
671 				flag = TTY_OVERRUN;
672 		}
673 
674 		for (i = 0; i < bytes_read; ++i) {
675 			ch = s->buf[i];
676 			if (uart_handle_sysrq_char(port, ch))
677 				continue;
678 
679 			if (lsr & port->ignore_status_mask)
680 				continue;
681 
682 			uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
683 					 flag);
684 		}
685 		rxlen -= bytes_read;
686 	}
687 
688 	tty_flip_buffer_push(&port->state->port);
689 }
690 
691 static void sc16is7xx_handle_tx(struct uart_port *port)
692 {
693 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
694 	struct tty_port *tport = &port->state->port;
695 	unsigned long flags;
696 	unsigned int txlen;
697 
698 	if (unlikely(port->x_char)) {
699 		sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
700 		port->icount.tx++;
701 		port->x_char = 0;
702 		return;
703 	}
704 
705 	if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) {
706 		uart_port_lock_irqsave(port, &flags);
707 		sc16is7xx_stop_tx(port);
708 		uart_port_unlock_irqrestore(port, flags);
709 		return;
710 	}
711 
712 	/* Limit to space available in TX FIFO */
713 	txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
714 	if (txlen > SC16IS7XX_FIFO_SIZE) {
715 		dev_err_ratelimited(port->dev,
716 			"chip reports %d free bytes in TX fifo, but it only has %d",
717 			txlen, SC16IS7XX_FIFO_SIZE);
718 		txlen = 0;
719 	}
720 
721 	txlen = uart_fifo_out(port, s->buf, txlen);
722 	sc16is7xx_fifo_write(port, s->buf, txlen);
723 
724 	uart_port_lock_irqsave(port, &flags);
725 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
726 		uart_write_wakeup(port);
727 
728 	if (kfifo_is_empty(&tport->xmit_fifo))
729 		sc16is7xx_stop_tx(port);
730 	else
731 		sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
732 	uart_port_unlock_irqrestore(port, flags);
733 }
734 
735 static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
736 {
737 	u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
738 	unsigned int mctrl = 0;
739 
740 	mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
741 	mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0;
742 	mctrl |= (msr & SC16IS7XX_MSR_CD_BIT)  ? TIOCM_CAR : 0;
743 	mctrl |= (msr & SC16IS7XX_MSR_RI_BIT)  ? TIOCM_RNG : 0;
744 	return mctrl;
745 }
746 
747 static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
748 {
749 	struct uart_port *port = &one->port;
750 	unsigned long flags;
751 	unsigned int status, changed;
752 
753 	lockdep_assert_held_once(&one->efr_lock);
754 
755 	status = sc16is7xx_get_hwmctrl(port);
756 	changed = status ^ one->old_mctrl;
757 
758 	if (changed == 0)
759 		return;
760 
761 	one->old_mctrl = status;
762 
763 	uart_port_lock_irqsave(port, &flags);
764 	if ((changed & TIOCM_RNG) && (status & TIOCM_RNG))
765 		port->icount.rng++;
766 	if (changed & TIOCM_DSR)
767 		port->icount.dsr++;
768 	if (changed & TIOCM_CAR)
769 		uart_handle_dcd_change(port, status & TIOCM_CAR);
770 	if (changed & TIOCM_CTS)
771 		uart_handle_cts_change(port, status & TIOCM_CTS);
772 
773 	wake_up_interruptible(&port->state->port.delta_msr_wait);
774 	uart_port_unlock_irqrestore(port, flags);
775 }
776 
777 static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
778 {
779 	bool rc = true;
780 	unsigned int iir, rxlen;
781 	struct uart_port *port = &s->p[portno].port;
782 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
783 
784 	mutex_lock(&one->efr_lock);
785 
786 	iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
787 	if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
788 		rc = false;
789 		goto out_port_irq;
790 	}
791 
792 	iir &= SC16IS7XX_IIR_ID_MASK;
793 
794 	switch (iir) {
795 	case SC16IS7XX_IIR_RDI_SRC:
796 	case SC16IS7XX_IIR_RLSE_SRC:
797 	case SC16IS7XX_IIR_RTOI_SRC:
798 	case SC16IS7XX_IIR_XOFFI_SRC:
799 		rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
800 
801 		/*
802 		 * There is a silicon bug that makes the chip report a
803 		 * time-out interrupt but no data in the FIFO. This is
804 		 * described in errata section 18.1.4.
805 		 *
806 		 * When this happens, read one byte from the FIFO to
807 		 * clear the interrupt.
808 		 */
809 		if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen)
810 			rxlen = 1;
811 
812 		if (rxlen)
813 			sc16is7xx_handle_rx(port, rxlen, iir);
814 		break;
815 		/* CTSRTS interrupt comes only when CTS goes inactive */
816 	case SC16IS7XX_IIR_CTSRTS_SRC:
817 	case SC16IS7XX_IIR_MSI_SRC:
818 		sc16is7xx_update_mlines(one);
819 		break;
820 	case SC16IS7XX_IIR_THRI_SRC:
821 		sc16is7xx_handle_tx(port);
822 		break;
823 	default:
824 		dev_err_ratelimited(port->dev,
825 				    "ttySC%i: Unexpected interrupt: %x",
826 				    port->line, iir);
827 		break;
828 	}
829 
830 out_port_irq:
831 	mutex_unlock(&one->efr_lock);
832 
833 	return rc;
834 }
835 
836 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
837 {
838 	bool keep_polling;
839 
840 	struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
841 
842 	do {
843 		int i;
844 
845 		keep_polling = false;
846 
847 		for (i = 0; i < s->devtype->nr_uart; ++i)
848 			keep_polling |= sc16is7xx_port_irq(s, i);
849 	} while (keep_polling);
850 
851 	return IRQ_HANDLED;
852 }
853 
854 static void sc16is7xx_tx_proc(struct kthread_work *ws)
855 {
856 	struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
857 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
858 
859 	if ((port->rs485.flags & SER_RS485_ENABLED) &&
860 	    (port->rs485.delay_rts_before_send > 0))
861 		msleep(port->rs485.delay_rts_before_send);
862 
863 	mutex_lock(&one->efr_lock);
864 	sc16is7xx_handle_tx(port);
865 	mutex_unlock(&one->efr_lock);
866 }
867 
868 static void sc16is7xx_reconf_rs485(struct uart_port *port)
869 {
870 	const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
871 			 SC16IS7XX_EFCR_RTS_INVERT_BIT;
872 	u32 efcr = 0;
873 	struct serial_rs485 *rs485 = &port->rs485;
874 	unsigned long irqflags;
875 
876 	uart_port_lock_irqsave(port, &irqflags);
877 	if (rs485->flags & SER_RS485_ENABLED) {
878 		efcr |=	SC16IS7XX_EFCR_AUTO_RS485_BIT;
879 
880 		if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
881 			efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
882 	}
883 	uart_port_unlock_irqrestore(port, irqflags);
884 
885 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
886 }
887 
888 static void sc16is7xx_reg_proc(struct kthread_work *ws)
889 {
890 	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
891 	struct sc16is7xx_one_config config;
892 	unsigned long irqflags;
893 
894 	uart_port_lock_irqsave(&one->port, &irqflags);
895 	config = one->config;
896 	memset(&one->config, 0, sizeof(one->config));
897 	uart_port_unlock_irqrestore(&one->port, irqflags);
898 
899 	if (config.flags & SC16IS7XX_RECONF_MD) {
900 		u8 mcr = 0;
901 
902 		/* Device ignores RTS setting when hardware flow is enabled */
903 		if (one->port.mctrl & TIOCM_RTS)
904 			mcr |= SC16IS7XX_MCR_RTS_BIT;
905 
906 		if (one->port.mctrl & TIOCM_DTR)
907 			mcr |= SC16IS7XX_MCR_DTR_BIT;
908 
909 		if (one->port.mctrl & TIOCM_LOOP)
910 			mcr |= SC16IS7XX_MCR_LOOP_BIT;
911 		sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
912 				      SC16IS7XX_MCR_RTS_BIT |
913 				      SC16IS7XX_MCR_DTR_BIT |
914 				      SC16IS7XX_MCR_LOOP_BIT,
915 				      mcr);
916 	}
917 
918 	if (config.flags & SC16IS7XX_RECONF_IER)
919 		sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
920 				      config.ier_mask, config.ier_val);
921 
922 	if (config.flags & SC16IS7XX_RECONF_RS485)
923 		sc16is7xx_reconf_rs485(&one->port);
924 }
925 
926 static void sc16is7xx_ms_proc(struct kthread_work *ws)
927 {
928 	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work);
929 	struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
930 
931 	if (one->port.state) {
932 		mutex_lock(&one->efr_lock);
933 		sc16is7xx_update_mlines(one);
934 		mutex_unlock(&one->efr_lock);
935 
936 		kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
937 	}
938 }
939 
940 static void sc16is7xx_enable_ms(struct uart_port *port)
941 {
942 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
943 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
944 
945 	lockdep_assert_held_once(&port->lock);
946 
947 	kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0);
948 }
949 
950 static void sc16is7xx_start_tx(struct uart_port *port)
951 {
952 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
953 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
954 
955 	kthread_queue_work(&s->kworker, &one->tx_work);
956 }
957 
958 static void sc16is7xx_throttle(struct uart_port *port)
959 {
960 	unsigned long flags;
961 
962 	/*
963 	 * Hardware flow control is enabled and thus the device ignores RTS
964 	 * value set in MCR register. Stop reading data from RX FIFO so the
965 	 * AutoRTS feature will de-activate RTS output.
966 	 */
967 	uart_port_lock_irqsave(port, &flags);
968 	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
969 	uart_port_unlock_irqrestore(port, flags);
970 }
971 
972 static void sc16is7xx_unthrottle(struct uart_port *port)
973 {
974 	unsigned long flags;
975 
976 	uart_port_lock_irqsave(port, &flags);
977 	sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT);
978 	uart_port_unlock_irqrestore(port, flags);
979 }
980 
981 static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
982 {
983 	unsigned int lsr;
984 
985 	lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
986 
987 	return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
988 }
989 
990 static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
991 {
992 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
993 
994 	/* Called with port lock taken so we can only return cached value */
995 	return one->old_mctrl;
996 }
997 
998 static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
999 {
1000 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1001 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1002 
1003 	one->config.flags |= SC16IS7XX_RECONF_MD;
1004 	kthread_queue_work(&s->kworker, &one->reg_work);
1005 }
1006 
1007 static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
1008 {
1009 	sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
1010 			      SC16IS7XX_LCR_TXBREAK_BIT,
1011 			      break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
1012 }
1013 
1014 static void sc16is7xx_set_termios(struct uart_port *port,
1015 				  struct ktermios *termios,
1016 				  const struct ktermios *old)
1017 {
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 	/* Configure flow control */
1076 	port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
1077 	if (termios->c_cflag & CRTSCTS) {
1078 		flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
1079 			SC16IS7XX_EFR_AUTORTS_BIT;
1080 		port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1081 	}
1082 	if (termios->c_iflag & IXON)
1083 		flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
1084 	if (termios->c_iflag & IXOFF)
1085 		flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
1086 
1087 	/* Update LCR register */
1088 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
1089 
1090 	/* Update EFR registers */
1091 	sc16is7xx_efr_lock(port);
1092 	sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
1093 	sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
1094 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1095 			      SC16IS7XX_EFR_FLOWCTRL_BITS, flow);
1096 	sc16is7xx_efr_unlock(port);
1097 
1098 	/* Get baud rate generator configuration */
1099 	baud = uart_get_baud_rate(port, termios, old,
1100 				  port->uartclk / 16 / 4 / 0xffff,
1101 				  port->uartclk / 16);
1102 
1103 	/* Setup baudrate generator */
1104 	baud = sc16is7xx_set_baud(port, baud);
1105 
1106 	uart_port_lock_irqsave(port, &flags);
1107 
1108 	/* Update timeout according to new baud rate */
1109 	uart_update_timeout(port, termios->c_cflag, baud);
1110 
1111 	if (UART_ENABLE_MS(port, termios->c_cflag))
1112 		sc16is7xx_enable_ms(port);
1113 
1114 	uart_port_unlock_irqrestore(port, flags);
1115 }
1116 
1117 static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios,
1118 				  struct serial_rs485 *rs485)
1119 {
1120 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1121 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1122 
1123 	if (rs485->flags & SER_RS485_ENABLED) {
1124 		/*
1125 		 * RTS signal is handled by HW, it's timing can't be influenced.
1126 		 * However, it's sometimes useful to delay TX even without RTS
1127 		 * control therefore we try to handle .delay_rts_before_send.
1128 		 */
1129 		if (rs485->delay_rts_after_send)
1130 			return -EINVAL;
1131 	}
1132 
1133 	one->config.flags |= SC16IS7XX_RECONF_RS485;
1134 	kthread_queue_work(&s->kworker, &one->reg_work);
1135 
1136 	return 0;
1137 }
1138 
1139 static int sc16is7xx_startup(struct uart_port *port)
1140 {
1141 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1142 	unsigned int val;
1143 	unsigned long flags;
1144 
1145 	sc16is7xx_power(port, 1);
1146 
1147 	/* Reset FIFOs*/
1148 	val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
1149 	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
1150 	udelay(5);
1151 	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
1152 			     SC16IS7XX_FCR_FIFO_BIT);
1153 
1154 	/* Enable EFR */
1155 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
1156 			     SC16IS7XX_LCR_CONF_MODE_B);
1157 
1158 	regcache_cache_bypass(one->regmap, true);
1159 
1160 	/* Enable write access to enhanced features and internal clock div */
1161 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1162 			      SC16IS7XX_EFR_ENABLE_BIT,
1163 			      SC16IS7XX_EFR_ENABLE_BIT);
1164 
1165 	/* Enable TCR/TLR */
1166 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1167 			      SC16IS7XX_MCR_TCRTLR_BIT,
1168 			      SC16IS7XX_MCR_TCRTLR_BIT);
1169 
1170 	/* Configure flow control levels */
1171 	/* Flow control halt level 48, resume level 24 */
1172 	sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
1173 			     SC16IS7XX_TCR_RX_RESUME(24) |
1174 			     SC16IS7XX_TCR_RX_HALT(48));
1175 
1176 	regcache_cache_bypass(one->regmap, false);
1177 
1178 	/* Now, initialize the UART */
1179 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
1180 
1181 	/* Enable IrDA mode if requested in DT */
1182 	/* This bit must be written with LCR[7] = 0 */
1183 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1184 			      SC16IS7XX_MCR_IRDA_BIT,
1185 			      one->irda_mode ?
1186 				SC16IS7XX_MCR_IRDA_BIT : 0);
1187 
1188 	/* Enable the Rx and Tx FIFO */
1189 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1190 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1191 			      SC16IS7XX_EFCR_TXDISABLE_BIT,
1192 			      0);
1193 
1194 	/* Enable RX, CTS change and modem lines interrupts */
1195 	val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT |
1196 	      SC16IS7XX_IER_MSI_BIT;
1197 	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1198 
1199 	/* Enable modem status polling */
1200 	uart_port_lock_irqsave(port, &flags);
1201 	sc16is7xx_enable_ms(port);
1202 	uart_port_unlock_irqrestore(port, flags);
1203 
1204 	return 0;
1205 }
1206 
1207 static void sc16is7xx_shutdown(struct uart_port *port)
1208 {
1209 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1210 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1211 
1212 	kthread_cancel_delayed_work_sync(&one->ms_work);
1213 
1214 	/* Disable all interrupts */
1215 	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1216 	/* Disable TX/RX */
1217 	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1218 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1219 			      SC16IS7XX_EFCR_TXDISABLE_BIT,
1220 			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1221 			      SC16IS7XX_EFCR_TXDISABLE_BIT);
1222 
1223 	sc16is7xx_power(port, 0);
1224 
1225 	kthread_flush_worker(&s->kworker);
1226 }
1227 
1228 static const char *sc16is7xx_type(struct uart_port *port)
1229 {
1230 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1231 
1232 	return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1233 }
1234 
1235 static int sc16is7xx_request_port(struct uart_port *port)
1236 {
1237 	/* Do nothing */
1238 	return 0;
1239 }
1240 
1241 static void sc16is7xx_config_port(struct uart_port *port, int flags)
1242 {
1243 	if (flags & UART_CONFIG_TYPE)
1244 		port->type = PORT_SC16IS7XX;
1245 }
1246 
1247 static int sc16is7xx_verify_port(struct uart_port *port,
1248 				 struct serial_struct *s)
1249 {
1250 	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1251 		return -EINVAL;
1252 	if (s->irq != port->irq)
1253 		return -EINVAL;
1254 
1255 	return 0;
1256 }
1257 
1258 static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1259 			 unsigned int oldstate)
1260 {
1261 	sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1262 }
1263 
1264 static void sc16is7xx_null_void(struct uart_port *port)
1265 {
1266 	/* Do nothing */
1267 }
1268 
1269 static const struct uart_ops sc16is7xx_ops = {
1270 	.tx_empty	= sc16is7xx_tx_empty,
1271 	.set_mctrl	= sc16is7xx_set_mctrl,
1272 	.get_mctrl	= sc16is7xx_get_mctrl,
1273 	.stop_tx	= sc16is7xx_stop_tx,
1274 	.start_tx	= sc16is7xx_start_tx,
1275 	.throttle	= sc16is7xx_throttle,
1276 	.unthrottle	= sc16is7xx_unthrottle,
1277 	.stop_rx	= sc16is7xx_stop_rx,
1278 	.enable_ms	= sc16is7xx_enable_ms,
1279 	.break_ctl	= sc16is7xx_break_ctl,
1280 	.startup	= sc16is7xx_startup,
1281 	.shutdown	= sc16is7xx_shutdown,
1282 	.set_termios	= sc16is7xx_set_termios,
1283 	.type		= sc16is7xx_type,
1284 	.request_port	= sc16is7xx_request_port,
1285 	.release_port	= sc16is7xx_null_void,
1286 	.config_port	= sc16is7xx_config_port,
1287 	.verify_port	= sc16is7xx_verify_port,
1288 	.pm		= sc16is7xx_pm,
1289 };
1290 
1291 #ifdef CONFIG_GPIOLIB
1292 static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1293 {
1294 	unsigned int val;
1295 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1296 	struct uart_port *port = &s->p[0].port;
1297 
1298 	val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1299 
1300 	return !!(val & BIT(offset));
1301 }
1302 
1303 static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1304 {
1305 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1306 	struct uart_port *port = &s->p[0].port;
1307 
1308 	sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1309 			      val ? BIT(offset) : 0);
1310 }
1311 
1312 static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1313 					  unsigned offset)
1314 {
1315 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1316 	struct uart_port *port = &s->p[0].port;
1317 
1318 	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1319 
1320 	return 0;
1321 }
1322 
1323 static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1324 					   unsigned offset, int val)
1325 {
1326 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1327 	struct uart_port *port = &s->p[0].port;
1328 	u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1329 
1330 	if (val)
1331 		state |= BIT(offset);
1332 	else
1333 		state &= ~BIT(offset);
1334 
1335 	/*
1336 	 * If we write IOSTATE first, and then IODIR, the output value is not
1337 	 * transferred to the corresponding I/O pin.
1338 	 * The datasheet states that each register bit will be transferred to
1339 	 * the corresponding I/O pin programmed as output when writing to
1340 	 * IOSTATE. Therefore, configure direction first with IODIR, and then
1341 	 * set value after with IOSTATE.
1342 	 */
1343 	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1344 			      BIT(offset));
1345 	sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
1346 
1347 	return 0;
1348 }
1349 
1350 static int sc16is7xx_gpio_init_valid_mask(struct gpio_chip *chip,
1351 					  unsigned long *valid_mask,
1352 					  unsigned int ngpios)
1353 {
1354 	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1355 
1356 	*valid_mask = s->gpio_valid_mask;
1357 
1358 	return 0;
1359 }
1360 
1361 static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s)
1362 {
1363 	struct device *dev = s->p[0].port.dev;
1364 
1365 	if (!s->devtype->nr_gpio)
1366 		return 0;
1367 
1368 	switch (s->mctrl_mask) {
1369 	case 0:
1370 		s->gpio_valid_mask = GENMASK(7, 0);
1371 		break;
1372 	case SC16IS7XX_IOCONTROL_MODEM_A_BIT:
1373 		s->gpio_valid_mask = GENMASK(3, 0);
1374 		break;
1375 	case SC16IS7XX_IOCONTROL_MODEM_B_BIT:
1376 		s->gpio_valid_mask = GENMASK(7, 4);
1377 		break;
1378 	default:
1379 		break;
1380 	}
1381 
1382 	if (s->gpio_valid_mask == 0)
1383 		return 0;
1384 
1385 	s->gpio.owner		 = THIS_MODULE;
1386 	s->gpio.parent		 = dev;
1387 	s->gpio.label		 = dev_name(dev);
1388 	s->gpio.init_valid_mask	 = sc16is7xx_gpio_init_valid_mask;
1389 	s->gpio.direction_input	 = sc16is7xx_gpio_direction_input;
1390 	s->gpio.get		 = sc16is7xx_gpio_get;
1391 	s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1392 	s->gpio.set		 = sc16is7xx_gpio_set;
1393 	s->gpio.base		 = -1;
1394 	s->gpio.ngpio		 = s->devtype->nr_gpio;
1395 	s->gpio.can_sleep	 = 1;
1396 
1397 	return gpiochip_add_data(&s->gpio, s);
1398 }
1399 #endif
1400 
1401 static void sc16is7xx_setup_irda_ports(struct sc16is7xx_port *s)
1402 {
1403 	int i;
1404 	int ret;
1405 	int count;
1406 	u32 irda_port[SC16IS7XX_MAX_PORTS];
1407 	struct device *dev = s->p[0].port.dev;
1408 
1409 	count = device_property_count_u32(dev, "irda-mode-ports");
1410 	if (count < 0 || count > ARRAY_SIZE(irda_port))
1411 		return;
1412 
1413 	ret = device_property_read_u32_array(dev, "irda-mode-ports",
1414 					     irda_port, count);
1415 	if (ret)
1416 		return;
1417 
1418 	for (i = 0; i < count; i++) {
1419 		if (irda_port[i] < s->devtype->nr_uart)
1420 			s->p[irda_port[i]].irda_mode = true;
1421 	}
1422 }
1423 
1424 /*
1425  * Configure ports designated to operate as modem control lines.
1426  */
1427 static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
1428 				       struct regmap *regmap)
1429 {
1430 	int i;
1431 	int ret;
1432 	int count;
1433 	u32 mctrl_port[SC16IS7XX_MAX_PORTS];
1434 	struct device *dev = s->p[0].port.dev;
1435 
1436 	count = device_property_count_u32(dev, "nxp,modem-control-line-ports");
1437 	if (count < 0 || count > ARRAY_SIZE(mctrl_port))
1438 		return 0;
1439 
1440 	ret = device_property_read_u32_array(dev, "nxp,modem-control-line-ports",
1441 					     mctrl_port, count);
1442 	if (ret)
1443 		return ret;
1444 
1445 	s->mctrl_mask = 0;
1446 
1447 	for (i = 0; i < count; i++) {
1448 		/* Use GPIO lines as modem control lines */
1449 		if (mctrl_port[i] == 0)
1450 			s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
1451 		else if (mctrl_port[i] == 1)
1452 			s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
1453 	}
1454 
1455 	if (s->mctrl_mask)
1456 		regmap_update_bits(
1457 			regmap,
1458 			SC16IS7XX_IOCONTROL_REG,
1459 			SC16IS7XX_IOCONTROL_MODEM_A_BIT |
1460 			SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask);
1461 
1462 	return 0;
1463 }
1464 
1465 static const struct serial_rs485 sc16is7xx_rs485_supported = {
1466 	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
1467 	.delay_rts_before_send = 1,
1468 	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
1469 };
1470 
1471 /* Reset device, purging any pending irq / data */
1472 static int sc16is7xx_reset(struct device *dev, struct regmap *regmap)
1473 {
1474 	struct gpio_desc *reset_gpio;
1475 
1476 	/* Assert reset GPIO if defined and valid. */
1477 	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
1478 	if (IS_ERR(reset_gpio))
1479 		return dev_err_probe(dev, PTR_ERR(reset_gpio), "Failed to get reset GPIO\n");
1480 
1481 	if (reset_gpio) {
1482 		/* The minimum reset pulse width is 3 us. */
1483 		fsleep(5);
1484 		gpiod_set_value_cansleep(reset_gpio, 0); /* Deassert GPIO */
1485 	} else {
1486 		/* Software reset */
1487 		regmap_write(regmap, SC16IS7XX_IOCONTROL_REG,
1488 			     SC16IS7XX_IOCONTROL_SRESET_BIT);
1489 	}
1490 
1491 	return 0;
1492 }
1493 
1494 int sc16is7xx_probe(struct device *dev, const struct sc16is7xx_devtype *devtype,
1495 		    struct regmap *regmaps[], int irq)
1496 {
1497 	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
1498 	unsigned int val;
1499 	u32 uartclk = 0;
1500 	int i, ret;
1501 	struct sc16is7xx_port *s;
1502 	bool port_registered[SC16IS7XX_MAX_PORTS];
1503 
1504 	for (i = 0; i < devtype->nr_uart; i++)
1505 		if (IS_ERR(regmaps[i]))
1506 			return PTR_ERR(regmaps[i]);
1507 
1508 	/*
1509 	 * This device does not have an identification register that would
1510 	 * tell us if we are really connected to the correct device.
1511 	 * The best we can do is to check if communication is at all possible.
1512 	 *
1513 	 * Note: regmap[0] is used in the probe function to access registers
1514 	 * common to all channels/ports, as it is guaranteed to be present on
1515 	 * all variants.
1516 	 */
1517 	ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val);
1518 	if (ret < 0)
1519 		return -EPROBE_DEFER;
1520 
1521 	/* Alloc port structure */
1522 	s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
1523 	if (!s) {
1524 		dev_err(dev, "Error allocating port structure\n");
1525 		return -ENOMEM;
1526 	}
1527 
1528 	/* Always ask for fixed clock rate from a property. */
1529 	device_property_read_u32(dev, "clock-frequency", &uartclk);
1530 
1531 	s->clk = devm_clk_get_optional(dev, NULL);
1532 	if (IS_ERR(s->clk))
1533 		return PTR_ERR(s->clk);
1534 
1535 	ret = clk_prepare_enable(s->clk);
1536 	if (ret)
1537 		return ret;
1538 
1539 	freq = clk_get_rate(s->clk);
1540 	if (freq == 0) {
1541 		if (uartclk)
1542 			freq = uartclk;
1543 		if (pfreq)
1544 			freq = *pfreq;
1545 		if (freq)
1546 			dev_dbg(dev, "Clock frequency: %luHz\n", freq);
1547 		else
1548 			return -EINVAL;
1549 	}
1550 
1551 	s->devtype = devtype;
1552 	dev_set_drvdata(dev, s);
1553 
1554 	kthread_init_worker(&s->kworker);
1555 	s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1556 				      "sc16is7xx");
1557 	if (IS_ERR(s->kworker_task)) {
1558 		ret = PTR_ERR(s->kworker_task);
1559 		goto out_clk;
1560 	}
1561 	sched_set_fifo(s->kworker_task);
1562 
1563 	ret = sc16is7xx_reset(dev, regmaps[0]);
1564 	if (ret)
1565 		goto out_kthread;
1566 
1567 	/* Mark each port line and status as uninitialised. */
1568 	for (i = 0; i < devtype->nr_uart; ++i) {
1569 		s->p[i].port.line = SC16IS7XX_MAX_DEVS;
1570 		port_registered[i] = false;
1571 	}
1572 
1573 	for (i = 0; i < devtype->nr_uart; ++i) {
1574 		ret = ida_alloc_max(&sc16is7xx_lines,
1575 				    SC16IS7XX_MAX_DEVS - 1, GFP_KERNEL);
1576 		if (ret < 0)
1577 			goto out_ports;
1578 
1579 		s->p[i].port.line = ret;
1580 
1581 		/* Initialize port data */
1582 		s->p[i].port.dev	= dev;
1583 		s->p[i].port.irq	= irq;
1584 		s->p[i].port.type	= PORT_SC16IS7XX;
1585 		s->p[i].port.fifosize	= SC16IS7XX_FIFO_SIZE;
1586 		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1587 		s->p[i].port.iobase	= i;
1588 		/*
1589 		 * Use all ones as membase to make sure uart_configure_port() in
1590 		 * serial_core.c does not abort for SPI/I2C devices where the
1591 		 * membase address is not applicable.
1592 		 */
1593 		s->p[i].port.membase	= (void __iomem *)~0;
1594 		s->p[i].port.iotype	= UPIO_PORT;
1595 		s->p[i].port.uartclk	= freq;
1596 		s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1597 		s->p[i].port.rs485_supported = sc16is7xx_rs485_supported;
1598 		s->p[i].port.ops	= &sc16is7xx_ops;
1599 		s->p[i].old_mctrl	= 0;
1600 		s->p[i].regmap		= regmaps[i];
1601 
1602 		mutex_init(&s->p[i].efr_lock);
1603 
1604 		ret = uart_get_rs485_mode(&s->p[i].port);
1605 		if (ret)
1606 			goto out_ports;
1607 
1608 		/* Disable all interrupts */
1609 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1610 		/* Disable TX/RX */
1611 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1612 				     SC16IS7XX_EFCR_RXDISABLE_BIT |
1613 				     SC16IS7XX_EFCR_TXDISABLE_BIT);
1614 
1615 		/* Initialize kthread work structs */
1616 		kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1617 		kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1618 		kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc);
1619 
1620 		/* Register port */
1621 		ret = uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1622 		if (ret)
1623 			goto out_ports;
1624 
1625 		port_registered[i] = true;
1626 
1627 		/* Enable EFR */
1628 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
1629 				     SC16IS7XX_LCR_CONF_MODE_B);
1630 
1631 		regcache_cache_bypass(regmaps[i], true);
1632 
1633 		/* Enable write access to enhanced features */
1634 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
1635 				     SC16IS7XX_EFR_ENABLE_BIT);
1636 
1637 		regcache_cache_bypass(regmaps[i], false);
1638 
1639 		/* Restore access to general registers */
1640 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
1641 
1642 		/* Go to suspend mode */
1643 		sc16is7xx_power(&s->p[i].port, 0);
1644 	}
1645 
1646 	sc16is7xx_setup_irda_ports(s);
1647 
1648 	ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]);
1649 	if (ret)
1650 		goto out_ports;
1651 
1652 #ifdef CONFIG_GPIOLIB
1653 	ret = sc16is7xx_setup_gpio_chip(s);
1654 	if (ret)
1655 		goto out_ports;
1656 #endif
1657 
1658 	/*
1659 	 * Setup interrupt. We first try to acquire the IRQ line as level IRQ.
1660 	 * If that succeeds, we can allow sharing the interrupt as well.
1661 	 * In case the interrupt controller doesn't support that, we fall
1662 	 * back to a non-shared falling-edge trigger.
1663 	 */
1664 	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1665 					IRQF_TRIGGER_LOW | IRQF_SHARED |
1666 					IRQF_ONESHOT,
1667 					dev_name(dev), s);
1668 	if (!ret)
1669 		return 0;
1670 
1671 	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1672 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1673 					dev_name(dev), s);
1674 	if (!ret)
1675 		return 0;
1676 
1677 #ifdef CONFIG_GPIOLIB
1678 	if (s->gpio_valid_mask)
1679 		gpiochip_remove(&s->gpio);
1680 #endif
1681 
1682 out_ports:
1683 	for (i = 0; i < devtype->nr_uart; i++) {
1684 		if (s->p[i].port.line < SC16IS7XX_MAX_DEVS)
1685 			ida_free(&sc16is7xx_lines, s->p[i].port.line);
1686 		if (port_registered[i])
1687 			uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1688 	}
1689 
1690 out_kthread:
1691 	kthread_stop(s->kworker_task);
1692 
1693 out_clk:
1694 	clk_disable_unprepare(s->clk);
1695 
1696 	return ret;
1697 }
1698 EXPORT_SYMBOL_GPL(sc16is7xx_probe);
1699 
1700 void sc16is7xx_remove(struct device *dev)
1701 {
1702 	struct sc16is7xx_port *s = dev_get_drvdata(dev);
1703 	int i;
1704 
1705 #ifdef CONFIG_GPIOLIB
1706 	if (s->gpio_valid_mask)
1707 		gpiochip_remove(&s->gpio);
1708 #endif
1709 
1710 	for (i = 0; i < s->devtype->nr_uart; i++) {
1711 		kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
1712 		ida_free(&sc16is7xx_lines, s->p[i].port.line);
1713 		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1714 		sc16is7xx_power(&s->p[i].port, 0);
1715 	}
1716 
1717 	kthread_flush_worker(&s->kworker);
1718 	kthread_stop(s->kworker_task);
1719 
1720 	clk_disable_unprepare(s->clk);
1721 }
1722 EXPORT_SYMBOL_GPL(sc16is7xx_remove);
1723 
1724 const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1725 	{ .compatible = "nxp,sc16is740",	.data = &sc16is74x_devtype, },
1726 	{ .compatible = "nxp,sc16is741",	.data = &sc16is74x_devtype, },
1727 	{ .compatible = "nxp,sc16is750",	.data = &sc16is750_devtype, },
1728 	{ .compatible = "nxp,sc16is752",	.data = &sc16is752_devtype, },
1729 	{ .compatible = "nxp,sc16is760",	.data = &sc16is760_devtype, },
1730 	{ .compatible = "nxp,sc16is762",	.data = &sc16is762_devtype, },
1731 	{ }
1732 };
1733 EXPORT_SYMBOL_GPL(sc16is7xx_dt_ids);
1734 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1735 
1736 const struct regmap_config sc16is7xx_regcfg = {
1737 	.reg_bits = 5,
1738 	.pad_bits = 3,
1739 	.val_bits = 8,
1740 	.cache_type = REGCACHE_MAPLE,
1741 	.volatile_reg = sc16is7xx_regmap_volatile,
1742 	.precious_reg = sc16is7xx_regmap_precious,
1743 	.writeable_noinc_reg = sc16is7xx_regmap_noinc,
1744 	.readable_noinc_reg = sc16is7xx_regmap_noinc,
1745 	.max_raw_read = SC16IS7XX_FIFO_SIZE,
1746 	.max_raw_write = SC16IS7XX_FIFO_SIZE,
1747 	.max_register = SC16IS7XX_EFCR_REG,
1748 };
1749 EXPORT_SYMBOL_GPL(sc16is7xx_regcfg);
1750 
1751 const char *sc16is7xx_regmap_name(u8 port_id)
1752 {
1753 	switch (port_id) {
1754 	case 0:	return "port0";
1755 	case 1:	return "port1";
1756 	default:
1757 		WARN_ON(true);
1758 		return NULL;
1759 	}
1760 }
1761 EXPORT_SYMBOL_GPL(sc16is7xx_regmap_name);
1762 
1763 unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
1764 {
1765 	/* CH1,CH0 are at bits 2:1. */
1766 	return port_id << 1;
1767 }
1768 EXPORT_SYMBOL_GPL(sc16is7xx_regmap_port_mask);
1769 
1770 static int __init sc16is7xx_init(void)
1771 {
1772 	return uart_register_driver(&sc16is7xx_uart);
1773 }
1774 module_init(sc16is7xx_init);
1775 
1776 static void __exit sc16is7xx_exit(void)
1777 {
1778 	uart_unregister_driver(&sc16is7xx_uart);
1779 }
1780 module_exit(sc16is7xx_exit);
1781 
1782 MODULE_LICENSE("GPL");
1783 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1784 MODULE_DESCRIPTION("SC16IS7xx tty serial core driver");
1785