xref: /openbmc/linux/drivers/tty/serial/max310x.c (revision 680ef72a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  Maxim (Dallas) MAX3107/8/9, MAX14830 serial driver
4  *
5  *  Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
6  *
7  *  Based on max3100.c, by Christian Pellegrin <chripell@evolware.org>
8  *  Based on max3110.c, by Feng Tang <feng.tang@intel.com>
9  *  Based on max3107.c, by Aavamobile
10  */
11 
12 #include <linux/bitops.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/device.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include <linux/regmap.h>
21 #include <linux/serial_core.h>
22 #include <linux/serial.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 #include <linux/spi/spi.h>
26 #include <linux/uaccess.h>
27 
28 #define MAX310X_NAME			"max310x"
29 #define MAX310X_MAJOR			204
30 #define MAX310X_MINOR			209
31 #define MAX310X_UART_NRMAX		16
32 
33 /* MAX310X register definitions */
34 #define MAX310X_RHR_REG			(0x00) /* RX FIFO */
35 #define MAX310X_THR_REG			(0x00) /* TX FIFO */
36 #define MAX310X_IRQEN_REG		(0x01) /* IRQ enable */
37 #define MAX310X_IRQSTS_REG		(0x02) /* IRQ status */
38 #define MAX310X_LSR_IRQEN_REG		(0x03) /* LSR IRQ enable */
39 #define MAX310X_LSR_IRQSTS_REG		(0x04) /* LSR IRQ status */
40 #define MAX310X_REG_05			(0x05)
41 #define MAX310X_SPCHR_IRQEN_REG		MAX310X_REG_05 /* Special char IRQ en */
42 #define MAX310X_SPCHR_IRQSTS_REG	(0x06) /* Special char IRQ status */
43 #define MAX310X_STS_IRQEN_REG		(0x07) /* Status IRQ enable */
44 #define MAX310X_STS_IRQSTS_REG		(0x08) /* Status IRQ status */
45 #define MAX310X_MODE1_REG		(0x09) /* MODE1 */
46 #define MAX310X_MODE2_REG		(0x0a) /* MODE2 */
47 #define MAX310X_LCR_REG			(0x0b) /* LCR */
48 #define MAX310X_RXTO_REG		(0x0c) /* RX timeout */
49 #define MAX310X_HDPIXDELAY_REG		(0x0d) /* Auto transceiver delays */
50 #define MAX310X_IRDA_REG		(0x0e) /* IRDA settings */
51 #define MAX310X_FLOWLVL_REG		(0x0f) /* Flow control levels */
52 #define MAX310X_FIFOTRIGLVL_REG		(0x10) /* FIFO IRQ trigger levels */
53 #define MAX310X_TXFIFOLVL_REG		(0x11) /* TX FIFO level */
54 #define MAX310X_RXFIFOLVL_REG		(0x12) /* RX FIFO level */
55 #define MAX310X_FLOWCTRL_REG		(0x13) /* Flow control */
56 #define MAX310X_XON1_REG		(0x14) /* XON1 character */
57 #define MAX310X_XON2_REG		(0x15) /* XON2 character */
58 #define MAX310X_XOFF1_REG		(0x16) /* XOFF1 character */
59 #define MAX310X_XOFF2_REG		(0x17) /* XOFF2 character */
60 #define MAX310X_GPIOCFG_REG		(0x18) /* GPIO config */
61 #define MAX310X_GPIODATA_REG		(0x19) /* GPIO data */
62 #define MAX310X_PLLCFG_REG		(0x1a) /* PLL config */
63 #define MAX310X_BRGCFG_REG		(0x1b) /* Baud rate generator conf */
64 #define MAX310X_BRGDIVLSB_REG		(0x1c) /* Baud rate divisor LSB */
65 #define MAX310X_BRGDIVMSB_REG		(0x1d) /* Baud rate divisor MSB */
66 #define MAX310X_CLKSRC_REG		(0x1e) /* Clock source */
67 #define MAX310X_REG_1F			(0x1f)
68 
69 #define MAX310X_REVID_REG		MAX310X_REG_1F /* Revision ID */
70 
71 #define MAX310X_GLOBALIRQ_REG		MAX310X_REG_1F /* Global IRQ (RO) */
72 #define MAX310X_GLOBALCMD_REG		MAX310X_REG_1F /* Global Command (WO) */
73 
74 /* Extended registers */
75 #define MAX310X_REVID_EXTREG		MAX310X_REG_05 /* Revision ID */
76 
77 /* IRQ register bits */
78 #define MAX310X_IRQ_LSR_BIT		(1 << 0) /* LSR interrupt */
79 #define MAX310X_IRQ_SPCHR_BIT		(1 << 1) /* Special char interrupt */
80 #define MAX310X_IRQ_STS_BIT		(1 << 2) /* Status interrupt */
81 #define MAX310X_IRQ_RXFIFO_BIT		(1 << 3) /* RX FIFO interrupt */
82 #define MAX310X_IRQ_TXFIFO_BIT		(1 << 4) /* TX FIFO interrupt */
83 #define MAX310X_IRQ_TXEMPTY_BIT		(1 << 5) /* TX FIFO empty interrupt */
84 #define MAX310X_IRQ_RXEMPTY_BIT		(1 << 6) /* RX FIFO empty interrupt */
85 #define MAX310X_IRQ_CTS_BIT		(1 << 7) /* CTS interrupt */
86 
87 /* LSR register bits */
88 #define MAX310X_LSR_RXTO_BIT		(1 << 0) /* RX timeout */
89 #define MAX310X_LSR_RXOVR_BIT		(1 << 1) /* RX overrun */
90 #define MAX310X_LSR_RXPAR_BIT		(1 << 2) /* RX parity error */
91 #define MAX310X_LSR_FRERR_BIT		(1 << 3) /* Frame error */
92 #define MAX310X_LSR_RXBRK_BIT		(1 << 4) /* RX break */
93 #define MAX310X_LSR_RXNOISE_BIT		(1 << 5) /* RX noise */
94 #define MAX310X_LSR_CTS_BIT		(1 << 7) /* CTS pin state */
95 
96 /* Special character register bits */
97 #define MAX310X_SPCHR_XON1_BIT		(1 << 0) /* XON1 character */
98 #define MAX310X_SPCHR_XON2_BIT		(1 << 1) /* XON2 character */
99 #define MAX310X_SPCHR_XOFF1_BIT		(1 << 2) /* XOFF1 character */
100 #define MAX310X_SPCHR_XOFF2_BIT		(1 << 3) /* XOFF2 character */
101 #define MAX310X_SPCHR_BREAK_BIT		(1 << 4) /* RX break */
102 #define MAX310X_SPCHR_MULTIDROP_BIT	(1 << 5) /* 9-bit multidrop addr char */
103 
104 /* Status register bits */
105 #define MAX310X_STS_GPIO0_BIT		(1 << 0) /* GPIO 0 interrupt */
106 #define MAX310X_STS_GPIO1_BIT		(1 << 1) /* GPIO 1 interrupt */
107 #define MAX310X_STS_GPIO2_BIT		(1 << 2) /* GPIO 2 interrupt */
108 #define MAX310X_STS_GPIO3_BIT		(1 << 3) /* GPIO 3 interrupt */
109 #define MAX310X_STS_CLKREADY_BIT	(1 << 5) /* Clock ready */
110 #define MAX310X_STS_SLEEP_BIT		(1 << 6) /* Sleep interrupt */
111 
112 /* MODE1 register bits */
113 #define MAX310X_MODE1_RXDIS_BIT		(1 << 0) /* RX disable */
114 #define MAX310X_MODE1_TXDIS_BIT		(1 << 1) /* TX disable */
115 #define MAX310X_MODE1_TXHIZ_BIT		(1 << 2) /* TX pin three-state */
116 #define MAX310X_MODE1_RTSHIZ_BIT	(1 << 3) /* RTS pin three-state */
117 #define MAX310X_MODE1_TRNSCVCTRL_BIT	(1 << 4) /* Transceiver ctrl enable */
118 #define MAX310X_MODE1_FORCESLEEP_BIT	(1 << 5) /* Force sleep mode */
119 #define MAX310X_MODE1_AUTOSLEEP_BIT	(1 << 6) /* Auto sleep enable */
120 #define MAX310X_MODE1_IRQSEL_BIT	(1 << 7) /* IRQ pin enable */
121 
122 /* MODE2 register bits */
123 #define MAX310X_MODE2_RST_BIT		(1 << 0) /* Chip reset */
124 #define MAX310X_MODE2_FIFORST_BIT	(1 << 1) /* FIFO reset */
125 #define MAX310X_MODE2_RXTRIGINV_BIT	(1 << 2) /* RX FIFO INT invert */
126 #define MAX310X_MODE2_RXEMPTINV_BIT	(1 << 3) /* RX FIFO empty INT invert */
127 #define MAX310X_MODE2_SPCHR_BIT		(1 << 4) /* Special chr detect enable */
128 #define MAX310X_MODE2_LOOPBACK_BIT	(1 << 5) /* Internal loopback enable */
129 #define MAX310X_MODE2_MULTIDROP_BIT	(1 << 6) /* 9-bit multidrop enable */
130 #define MAX310X_MODE2_ECHOSUPR_BIT	(1 << 7) /* ECHO suppression enable */
131 
132 /* LCR register bits */
133 #define MAX310X_LCR_LENGTH0_BIT		(1 << 0) /* Word length bit 0 */
134 #define MAX310X_LCR_LENGTH1_BIT		(1 << 1) /* Word length bit 1
135 						  *
136 						  * Word length bits table:
137 						  * 00 -> 5 bit words
138 						  * 01 -> 6 bit words
139 						  * 10 -> 7 bit words
140 						  * 11 -> 8 bit words
141 						  */
142 #define MAX310X_LCR_STOPLEN_BIT		(1 << 2) /* STOP length bit
143 						  *
144 						  * STOP length bit table:
145 						  * 0 -> 1 stop bit
146 						  * 1 -> 1-1.5 stop bits if
147 						  *      word length is 5,
148 						  *      2 stop bits otherwise
149 						  */
150 #define MAX310X_LCR_PARITY_BIT		(1 << 3) /* Parity bit enable */
151 #define MAX310X_LCR_EVENPARITY_BIT	(1 << 4) /* Even parity bit enable */
152 #define MAX310X_LCR_FORCEPARITY_BIT	(1 << 5) /* 9-bit multidrop parity */
153 #define MAX310X_LCR_TXBREAK_BIT		(1 << 6) /* TX break enable */
154 #define MAX310X_LCR_RTS_BIT		(1 << 7) /* RTS pin control */
155 
156 /* IRDA register bits */
157 #define MAX310X_IRDA_IRDAEN_BIT		(1 << 0) /* IRDA mode enable */
158 #define MAX310X_IRDA_SIR_BIT		(1 << 1) /* SIR mode enable */
159 
160 /* Flow control trigger level register masks */
161 #define MAX310X_FLOWLVL_HALT_MASK	(0x000f) /* Flow control halt level */
162 #define MAX310X_FLOWLVL_RES_MASK	(0x00f0) /* Flow control resume level */
163 #define MAX310X_FLOWLVL_HALT(words)	((words / 8) & 0x0f)
164 #define MAX310X_FLOWLVL_RES(words)	(((words / 8) & 0x0f) << 4)
165 
166 /* FIFO interrupt trigger level register masks */
167 #define MAX310X_FIFOTRIGLVL_TX_MASK	(0x0f) /* TX FIFO trigger level */
168 #define MAX310X_FIFOTRIGLVL_RX_MASK	(0xf0) /* RX FIFO trigger level */
169 #define MAX310X_FIFOTRIGLVL_TX(words)	((words / 8) & 0x0f)
170 #define MAX310X_FIFOTRIGLVL_RX(words)	(((words / 8) & 0x0f) << 4)
171 
172 /* Flow control register bits */
173 #define MAX310X_FLOWCTRL_AUTORTS_BIT	(1 << 0) /* Auto RTS flow ctrl enable */
174 #define MAX310X_FLOWCTRL_AUTOCTS_BIT	(1 << 1) /* Auto CTS flow ctrl enable */
175 #define MAX310X_FLOWCTRL_GPIADDR_BIT	(1 << 2) /* Enables that GPIO inputs
176 						  * are used in conjunction with
177 						  * XOFF2 for definition of
178 						  * special character */
179 #define MAX310X_FLOWCTRL_SWFLOWEN_BIT	(1 << 3) /* Auto SW flow ctrl enable */
180 #define MAX310X_FLOWCTRL_SWFLOW0_BIT	(1 << 4) /* SWFLOW bit 0 */
181 #define MAX310X_FLOWCTRL_SWFLOW1_BIT	(1 << 5) /* SWFLOW bit 1
182 						  *
183 						  * SWFLOW bits 1 & 0 table:
184 						  * 00 -> no transmitter flow
185 						  *       control
186 						  * 01 -> receiver compares
187 						  *       XON2 and XOFF2
188 						  *       and controls
189 						  *       transmitter
190 						  * 10 -> receiver compares
191 						  *       XON1 and XOFF1
192 						  *       and controls
193 						  *       transmitter
194 						  * 11 -> receiver compares
195 						  *       XON1, XON2, XOFF1 and
196 						  *       XOFF2 and controls
197 						  *       transmitter
198 						  */
199 #define MAX310X_FLOWCTRL_SWFLOW2_BIT	(1 << 6) /* SWFLOW bit 2 */
200 #define MAX310X_FLOWCTRL_SWFLOW3_BIT	(1 << 7) /* SWFLOW bit 3
201 						  *
202 						  * SWFLOW bits 3 & 2 table:
203 						  * 00 -> no received flow
204 						  *       control
205 						  * 01 -> transmitter generates
206 						  *       XON2 and XOFF2
207 						  * 10 -> transmitter generates
208 						  *       XON1 and XOFF1
209 						  * 11 -> transmitter generates
210 						  *       XON1, XON2, XOFF1 and
211 						  *       XOFF2
212 						  */
213 
214 /* PLL configuration register masks */
215 #define MAX310X_PLLCFG_PREDIV_MASK	(0x3f) /* PLL predivision value */
216 #define MAX310X_PLLCFG_PLLFACTOR_MASK	(0xc0) /* PLL multiplication factor */
217 
218 /* Baud rate generator configuration register bits */
219 #define MAX310X_BRGCFG_2XMODE_BIT	(1 << 4) /* Double baud rate */
220 #define MAX310X_BRGCFG_4XMODE_BIT	(1 << 5) /* Quadruple baud rate */
221 
222 /* Clock source register bits */
223 #define MAX310X_CLKSRC_CRYST_BIT	(1 << 1) /* Crystal osc enable */
224 #define MAX310X_CLKSRC_PLL_BIT		(1 << 2) /* PLL enable */
225 #define MAX310X_CLKSRC_PLLBYP_BIT	(1 << 3) /* PLL bypass */
226 #define MAX310X_CLKSRC_EXTCLK_BIT	(1 << 4) /* External clock enable */
227 #define MAX310X_CLKSRC_CLK2RTS_BIT	(1 << 7) /* Baud clk to RTS pin */
228 
229 /* Global commands */
230 #define MAX310X_EXTREG_ENBL		(0xce)
231 #define MAX310X_EXTREG_DSBL		(0xcd)
232 
233 /* Misc definitions */
234 #define MAX310X_FIFO_SIZE		(128)
235 #define MAX310x_REV_MASK		(0xf8)
236 
237 /* MAX3107 specific */
238 #define MAX3107_REV_ID			(0xa0)
239 
240 /* MAX3109 specific */
241 #define MAX3109_REV_ID			(0xc0)
242 
243 /* MAX14830 specific */
244 #define MAX14830_BRGCFG_CLKDIS_BIT	(1 << 6) /* Clock Disable */
245 #define MAX14830_REV_ID			(0xb0)
246 
247 struct max310x_devtype {
248 	char	name[9];
249 	int	nr;
250 	int	(*detect)(struct device *);
251 	void	(*power)(struct uart_port *, int);
252 };
253 
254 struct max310x_one {
255 	struct uart_port	port;
256 	struct work_struct	tx_work;
257 	struct work_struct	md_work;
258 	struct work_struct	rs_work;
259 };
260 
261 struct max310x_port {
262 	struct max310x_devtype	*devtype;
263 	struct regmap		*regmap;
264 	struct mutex		mutex;
265 	struct clk		*clk;
266 #ifdef CONFIG_GPIOLIB
267 	struct gpio_chip	gpio;
268 #endif
269 	struct max310x_one	p[0];
270 };
271 
272 static struct uart_driver max310x_uart = {
273 	.owner		= THIS_MODULE,
274 	.driver_name	= MAX310X_NAME,
275 	.dev_name	= "ttyMAX",
276 	.major		= MAX310X_MAJOR,
277 	.minor		= MAX310X_MINOR,
278 	.nr		= MAX310X_UART_NRMAX,
279 };
280 
281 static DECLARE_BITMAP(max310x_lines, MAX310X_UART_NRMAX);
282 
283 static u8 max310x_port_read(struct uart_port *port, u8 reg)
284 {
285 	struct max310x_port *s = dev_get_drvdata(port->dev);
286 	unsigned int val = 0;
287 
288 	regmap_read(s->regmap, port->iobase + reg, &val);
289 
290 	return val;
291 }
292 
293 static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
294 {
295 	struct max310x_port *s = dev_get_drvdata(port->dev);
296 
297 	regmap_write(s->regmap, port->iobase + reg, val);
298 }
299 
300 static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
301 {
302 	struct max310x_port *s = dev_get_drvdata(port->dev);
303 
304 	regmap_update_bits(s->regmap, port->iobase + reg, mask, val);
305 }
306 
307 static int max3107_detect(struct device *dev)
308 {
309 	struct max310x_port *s = dev_get_drvdata(dev);
310 	unsigned int val = 0;
311 	int ret;
312 
313 	ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val);
314 	if (ret)
315 		return ret;
316 
317 	if (((val & MAX310x_REV_MASK) != MAX3107_REV_ID)) {
318 		dev_err(dev,
319 			"%s ID 0x%02x does not match\n", s->devtype->name, val);
320 		return -ENODEV;
321 	}
322 
323 	return 0;
324 }
325 
326 static int max3108_detect(struct device *dev)
327 {
328 	struct max310x_port *s = dev_get_drvdata(dev);
329 	unsigned int val = 0;
330 	int ret;
331 
332 	/* MAX3108 have not REV ID register, we just check default value
333 	 * from clocksource register to make sure everything works.
334 	 */
335 	ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val);
336 	if (ret)
337 		return ret;
338 
339 	if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) {
340 		dev_err(dev, "%s not present\n", s->devtype->name);
341 		return -ENODEV;
342 	}
343 
344 	return 0;
345 }
346 
347 static int max3109_detect(struct device *dev)
348 {
349 	struct max310x_port *s = dev_get_drvdata(dev);
350 	unsigned int val = 0;
351 	int ret;
352 
353 	ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
354 			   MAX310X_EXTREG_ENBL);
355 	if (ret)
356 		return ret;
357 
358 	regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
359 	regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
360 	if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
361 		dev_err(dev,
362 			"%s ID 0x%02x does not match\n", s->devtype->name, val);
363 		return -ENODEV;
364 	}
365 
366 	return 0;
367 }
368 
369 static void max310x_power(struct uart_port *port, int on)
370 {
371 	max310x_port_update(port, MAX310X_MODE1_REG,
372 			    MAX310X_MODE1_FORCESLEEP_BIT,
373 			    on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT);
374 	if (on)
375 		msleep(50);
376 }
377 
378 static int max14830_detect(struct device *dev)
379 {
380 	struct max310x_port *s = dev_get_drvdata(dev);
381 	unsigned int val = 0;
382 	int ret;
383 
384 	ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
385 			   MAX310X_EXTREG_ENBL);
386 	if (ret)
387 		return ret;
388 
389 	regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
390 	regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
391 	if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
392 		dev_err(dev,
393 			"%s ID 0x%02x does not match\n", s->devtype->name, val);
394 		return -ENODEV;
395 	}
396 
397 	return 0;
398 }
399 
400 static void max14830_power(struct uart_port *port, int on)
401 {
402 	max310x_port_update(port, MAX310X_BRGCFG_REG,
403 			    MAX14830_BRGCFG_CLKDIS_BIT,
404 			    on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT);
405 	if (on)
406 		msleep(50);
407 }
408 
409 static const struct max310x_devtype max3107_devtype = {
410 	.name	= "MAX3107",
411 	.nr	= 1,
412 	.detect	= max3107_detect,
413 	.power	= max310x_power,
414 };
415 
416 static const struct max310x_devtype max3108_devtype = {
417 	.name	= "MAX3108",
418 	.nr	= 1,
419 	.detect	= max3108_detect,
420 	.power	= max310x_power,
421 };
422 
423 static const struct max310x_devtype max3109_devtype = {
424 	.name	= "MAX3109",
425 	.nr	= 2,
426 	.detect	= max3109_detect,
427 	.power	= max310x_power,
428 };
429 
430 static const struct max310x_devtype max14830_devtype = {
431 	.name	= "MAX14830",
432 	.nr	= 4,
433 	.detect	= max14830_detect,
434 	.power	= max14830_power,
435 };
436 
437 static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
438 {
439 	switch (reg & 0x1f) {
440 	case MAX310X_IRQSTS_REG:
441 	case MAX310X_LSR_IRQSTS_REG:
442 	case MAX310X_SPCHR_IRQSTS_REG:
443 	case MAX310X_STS_IRQSTS_REG:
444 	case MAX310X_TXFIFOLVL_REG:
445 	case MAX310X_RXFIFOLVL_REG:
446 		return false;
447 	default:
448 		break;
449 	}
450 
451 	return true;
452 }
453 
454 static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
455 {
456 	switch (reg & 0x1f) {
457 	case MAX310X_RHR_REG:
458 	case MAX310X_IRQSTS_REG:
459 	case MAX310X_LSR_IRQSTS_REG:
460 	case MAX310X_SPCHR_IRQSTS_REG:
461 	case MAX310X_STS_IRQSTS_REG:
462 	case MAX310X_TXFIFOLVL_REG:
463 	case MAX310X_RXFIFOLVL_REG:
464 	case MAX310X_GPIODATA_REG:
465 	case MAX310X_BRGDIVLSB_REG:
466 	case MAX310X_REG_05:
467 	case MAX310X_REG_1F:
468 		return true;
469 	default:
470 		break;
471 	}
472 
473 	return false;
474 }
475 
476 static bool max310x_reg_precious(struct device *dev, unsigned int reg)
477 {
478 	switch (reg & 0x1f) {
479 	case MAX310X_RHR_REG:
480 	case MAX310X_IRQSTS_REG:
481 	case MAX310X_SPCHR_IRQSTS_REG:
482 	case MAX310X_STS_IRQSTS_REG:
483 		return true;
484 	default:
485 		break;
486 	}
487 
488 	return false;
489 }
490 
491 static int max310x_set_baud(struct uart_port *port, int baud)
492 {
493 	unsigned int mode = 0, clk = port->uartclk, div = clk / baud;
494 
495 	/* Check for minimal value for divider */
496 	if (div < 16)
497 		div = 16;
498 
499 	if (clk % baud && (div / 16) < 0x8000) {
500 		/* Mode x2 */
501 		mode = MAX310X_BRGCFG_2XMODE_BIT;
502 		clk = port->uartclk * 2;
503 		div = clk / baud;
504 
505 		if (clk % baud && (div / 16) < 0x8000) {
506 			/* Mode x4 */
507 			mode = MAX310X_BRGCFG_4XMODE_BIT;
508 			clk = port->uartclk * 4;
509 			div = clk / baud;
510 		}
511 	}
512 
513 	max310x_port_write(port, MAX310X_BRGDIVMSB_REG, (div / 16) >> 8);
514 	max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div / 16);
515 	max310x_port_write(port, MAX310X_BRGCFG_REG, (div % 16) | mode);
516 
517 	return DIV_ROUND_CLOSEST(clk, div);
518 }
519 
520 static int max310x_update_best_err(unsigned long f, long *besterr)
521 {
522 	/* Use baudrate 115200 for calculate error */
523 	long err = f % (115200 * 16);
524 
525 	if ((*besterr < 0) || (*besterr > err)) {
526 		*besterr = err;
527 		return 0;
528 	}
529 
530 	return 1;
531 }
532 
533 static int max310x_set_ref_clk(struct max310x_port *s, unsigned long freq,
534 			       bool xtal)
535 {
536 	unsigned int div, clksrc, pllcfg = 0;
537 	long besterr = -1;
538 	unsigned long fdiv, fmul, bestfreq = freq;
539 
540 	/* First, update error without PLL */
541 	max310x_update_best_err(freq, &besterr);
542 
543 	/* Try all possible PLL dividers */
544 	for (div = 1; (div <= 63) && besterr; div++) {
545 		fdiv = DIV_ROUND_CLOSEST(freq, div);
546 
547 		/* Try multiplier 6 */
548 		fmul = fdiv * 6;
549 		if ((fdiv >= 500000) && (fdiv <= 800000))
550 			if (!max310x_update_best_err(fmul, &besterr)) {
551 				pllcfg = (0 << 6) | div;
552 				bestfreq = fmul;
553 			}
554 		/* Try multiplier 48 */
555 		fmul = fdiv * 48;
556 		if ((fdiv >= 850000) && (fdiv <= 1200000))
557 			if (!max310x_update_best_err(fmul, &besterr)) {
558 				pllcfg = (1 << 6) | div;
559 				bestfreq = fmul;
560 			}
561 		/* Try multiplier 96 */
562 		fmul = fdiv * 96;
563 		if ((fdiv >= 425000) && (fdiv <= 1000000))
564 			if (!max310x_update_best_err(fmul, &besterr)) {
565 				pllcfg = (2 << 6) | div;
566 				bestfreq = fmul;
567 			}
568 		/* Try multiplier 144 */
569 		fmul = fdiv * 144;
570 		if ((fdiv >= 390000) && (fdiv <= 667000))
571 			if (!max310x_update_best_err(fmul, &besterr)) {
572 				pllcfg = (3 << 6) | div;
573 				bestfreq = fmul;
574 			}
575 	}
576 
577 	/* Configure clock source */
578 	clksrc = xtal ? MAX310X_CLKSRC_CRYST_BIT : MAX310X_CLKSRC_EXTCLK_BIT;
579 
580 	/* Configure PLL */
581 	if (pllcfg) {
582 		clksrc |= MAX310X_CLKSRC_PLL_BIT;
583 		regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
584 	} else
585 		clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
586 
587 	regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
588 
589 	/* Wait for crystal */
590 	if (pllcfg && xtal)
591 		msleep(10);
592 
593 	return (int)bestfreq;
594 }
595 
596 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
597 {
598 	unsigned int sts, ch, flag;
599 
600 	if (unlikely(rxlen >= port->fifosize)) {
601 		dev_warn_ratelimited(port->dev, "Possible RX FIFO overrun\n");
602 		port->icount.buf_overrun++;
603 		/* Ensure sanity of RX level */
604 		rxlen = port->fifosize;
605 	}
606 
607 	while (rxlen--) {
608 		ch = max310x_port_read(port, MAX310X_RHR_REG);
609 		sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
610 
611 		sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT |
612 		       MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT;
613 
614 		port->icount.rx++;
615 		flag = TTY_NORMAL;
616 
617 		if (unlikely(sts)) {
618 			if (sts & MAX310X_LSR_RXBRK_BIT) {
619 				port->icount.brk++;
620 				if (uart_handle_break(port))
621 					continue;
622 			} else if (sts & MAX310X_LSR_RXPAR_BIT)
623 				port->icount.parity++;
624 			else if (sts & MAX310X_LSR_FRERR_BIT)
625 				port->icount.frame++;
626 			else if (sts & MAX310X_LSR_RXOVR_BIT)
627 				port->icount.overrun++;
628 
629 			sts &= port->read_status_mask;
630 			if (sts & MAX310X_LSR_RXBRK_BIT)
631 				flag = TTY_BREAK;
632 			else if (sts & MAX310X_LSR_RXPAR_BIT)
633 				flag = TTY_PARITY;
634 			else if (sts & MAX310X_LSR_FRERR_BIT)
635 				flag = TTY_FRAME;
636 			else if (sts & MAX310X_LSR_RXOVR_BIT)
637 				flag = TTY_OVERRUN;
638 		}
639 
640 		if (uart_handle_sysrq_char(port, ch))
641 			continue;
642 
643 		if (sts & port->ignore_status_mask)
644 			continue;
645 
646 		uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag);
647 	}
648 
649 	tty_flip_buffer_push(&port->state->port);
650 }
651 
652 static void max310x_handle_tx(struct uart_port *port)
653 {
654 	struct circ_buf *xmit = &port->state->xmit;
655 	unsigned int txlen, to_send;
656 
657 	if (unlikely(port->x_char)) {
658 		max310x_port_write(port, MAX310X_THR_REG, port->x_char);
659 		port->icount.tx++;
660 		port->x_char = 0;
661 		return;
662 	}
663 
664 	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
665 		return;
666 
667 	/* Get length of data pending in circular buffer */
668 	to_send = uart_circ_chars_pending(xmit);
669 	if (likely(to_send)) {
670 		/* Limit to size of TX FIFO */
671 		txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
672 		txlen = port->fifosize - txlen;
673 		to_send = (to_send > txlen) ? txlen : to_send;
674 
675 		/* Add data to send */
676 		port->icount.tx += to_send;
677 		while (to_send--) {
678 			max310x_port_write(port, MAX310X_THR_REG,
679 					   xmit->buf[xmit->tail]);
680 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
681 		}
682 	}
683 
684 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
685 		uart_write_wakeup(port);
686 }
687 
688 static void max310x_port_irq(struct max310x_port *s, int portno)
689 {
690 	struct uart_port *port = &s->p[portno].port;
691 
692 	do {
693 		unsigned int ists, lsr, rxlen;
694 
695 		/* Read IRQ status & RX FIFO level */
696 		ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
697 		rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
698 		if (!ists && !rxlen)
699 			break;
700 
701 		if (ists & MAX310X_IRQ_CTS_BIT) {
702 			lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
703 			uart_handle_cts_change(port,
704 					       !!(lsr & MAX310X_LSR_CTS_BIT));
705 		}
706 		if (rxlen)
707 			max310x_handle_rx(port, rxlen);
708 		if (ists & MAX310X_IRQ_TXEMPTY_BIT) {
709 			mutex_lock(&s->mutex);
710 			max310x_handle_tx(port);
711 			mutex_unlock(&s->mutex);
712 		}
713 	} while (1);
714 }
715 
716 static irqreturn_t max310x_ist(int irq, void *dev_id)
717 {
718 	struct max310x_port *s = (struct max310x_port *)dev_id;
719 
720 	if (s->devtype->nr > 1) {
721 		do {
722 			unsigned int val = ~0;
723 
724 			WARN_ON_ONCE(regmap_read(s->regmap,
725 						 MAX310X_GLOBALIRQ_REG, &val));
726 			val = ((1 << s->devtype->nr) - 1) & ~val;
727 			if (!val)
728 				break;
729 			max310x_port_irq(s, fls(val) - 1);
730 		} while (1);
731 	} else
732 		max310x_port_irq(s, 0);
733 
734 	return IRQ_HANDLED;
735 }
736 
737 static void max310x_wq_proc(struct work_struct *ws)
738 {
739 	struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
740 	struct max310x_port *s = dev_get_drvdata(one->port.dev);
741 
742 	mutex_lock(&s->mutex);
743 	max310x_handle_tx(&one->port);
744 	mutex_unlock(&s->mutex);
745 }
746 
747 static void max310x_start_tx(struct uart_port *port)
748 {
749 	struct max310x_one *one = container_of(port, struct max310x_one, port);
750 
751 	if (!work_pending(&one->tx_work))
752 		schedule_work(&one->tx_work);
753 }
754 
755 static unsigned int max310x_tx_empty(struct uart_port *port)
756 {
757 	unsigned int lvl, sts;
758 
759 	lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
760 	sts = max310x_port_read(port, MAX310X_IRQSTS_REG);
761 
762 	return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0;
763 }
764 
765 static unsigned int max310x_get_mctrl(struct uart_port *port)
766 {
767 	/* DCD and DSR are not wired and CTS/RTS is handled automatically
768 	 * so just indicate DSR and CAR asserted
769 	 */
770 	return TIOCM_DSR | TIOCM_CAR;
771 }
772 
773 static void max310x_md_proc(struct work_struct *ws)
774 {
775 	struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
776 
777 	max310x_port_update(&one->port, MAX310X_MODE2_REG,
778 			    MAX310X_MODE2_LOOPBACK_BIT,
779 			    (one->port.mctrl & TIOCM_LOOP) ?
780 			    MAX310X_MODE2_LOOPBACK_BIT : 0);
781 }
782 
783 static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
784 {
785 	struct max310x_one *one = container_of(port, struct max310x_one, port);
786 
787 	schedule_work(&one->md_work);
788 }
789 
790 static void max310x_break_ctl(struct uart_port *port, int break_state)
791 {
792 	max310x_port_update(port, MAX310X_LCR_REG,
793 			    MAX310X_LCR_TXBREAK_BIT,
794 			    break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
795 }
796 
797 static void max310x_set_termios(struct uart_port *port,
798 				struct ktermios *termios,
799 				struct ktermios *old)
800 {
801 	unsigned int lcr = 0, flow = 0;
802 	int baud;
803 
804 	/* Mask termios capabilities we don't support */
805 	termios->c_cflag &= ~CMSPAR;
806 
807 	/* Word size */
808 	switch (termios->c_cflag & CSIZE) {
809 	case CS5:
810 		break;
811 	case CS6:
812 		lcr = MAX310X_LCR_LENGTH0_BIT;
813 		break;
814 	case CS7:
815 		lcr = MAX310X_LCR_LENGTH1_BIT;
816 		break;
817 	case CS8:
818 	default:
819 		lcr = MAX310X_LCR_LENGTH1_BIT | MAX310X_LCR_LENGTH0_BIT;
820 		break;
821 	}
822 
823 	/* Parity */
824 	if (termios->c_cflag & PARENB) {
825 		lcr |= MAX310X_LCR_PARITY_BIT;
826 		if (!(termios->c_cflag & PARODD))
827 			lcr |= MAX310X_LCR_EVENPARITY_BIT;
828 	}
829 
830 	/* Stop bits */
831 	if (termios->c_cflag & CSTOPB)
832 		lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
833 
834 	/* Update LCR register */
835 	max310x_port_write(port, MAX310X_LCR_REG, lcr);
836 
837 	/* Set read status mask */
838 	port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
839 	if (termios->c_iflag & INPCK)
840 		port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
841 					  MAX310X_LSR_FRERR_BIT;
842 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
843 		port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
844 
845 	/* Set status ignore mask */
846 	port->ignore_status_mask = 0;
847 	if (termios->c_iflag & IGNBRK)
848 		port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
849 	if (!(termios->c_cflag & CREAD))
850 		port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
851 					    MAX310X_LSR_RXOVR_BIT |
852 					    MAX310X_LSR_FRERR_BIT |
853 					    MAX310X_LSR_RXBRK_BIT;
854 
855 	/* Configure flow control */
856 	max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
857 	max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
858 	if (termios->c_cflag & CRTSCTS)
859 		flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
860 			MAX310X_FLOWCTRL_AUTORTS_BIT;
861 	if (termios->c_iflag & IXON)
862 		flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
863 			MAX310X_FLOWCTRL_SWFLOWEN_BIT;
864 	if (termios->c_iflag & IXOFF)
865 		flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
866 			MAX310X_FLOWCTRL_SWFLOWEN_BIT;
867 	max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
868 
869 	/* Get baud rate generator configuration */
870 	baud = uart_get_baud_rate(port, termios, old,
871 				  port->uartclk / 16 / 0xffff,
872 				  port->uartclk / 4);
873 
874 	/* Setup baudrate generator */
875 	baud = max310x_set_baud(port, baud);
876 
877 	/* Update timeout according to new baud rate */
878 	uart_update_timeout(port, termios->c_cflag, baud);
879 }
880 
881 static void max310x_rs_proc(struct work_struct *ws)
882 {
883 	struct max310x_one *one = container_of(ws, struct max310x_one, rs_work);
884 	unsigned int val;
885 
886 	val = (one->port.rs485.delay_rts_before_send << 4) |
887 		one->port.rs485.delay_rts_after_send;
888 	max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, val);
889 
890 	if (one->port.rs485.flags & SER_RS485_ENABLED) {
891 		max310x_port_update(&one->port, MAX310X_MODE1_REG,
892 				MAX310X_MODE1_TRNSCVCTRL_BIT,
893 				MAX310X_MODE1_TRNSCVCTRL_BIT);
894 		max310x_port_update(&one->port, MAX310X_MODE2_REG,
895 				MAX310X_MODE2_ECHOSUPR_BIT,
896 				MAX310X_MODE2_ECHOSUPR_BIT);
897 	} else {
898 		max310x_port_update(&one->port, MAX310X_MODE1_REG,
899 				MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
900 		max310x_port_update(&one->port, MAX310X_MODE2_REG,
901 				MAX310X_MODE2_ECHOSUPR_BIT, 0);
902 	}
903 }
904 
905 static int max310x_rs485_config(struct uart_port *port,
906 				struct serial_rs485 *rs485)
907 {
908 	struct max310x_one *one = container_of(port, struct max310x_one, port);
909 
910 	if ((rs485->delay_rts_before_send > 0x0f) ||
911 	    (rs485->delay_rts_after_send > 0x0f))
912 		return -ERANGE;
913 
914 	rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_ENABLED;
915 	memset(rs485->padding, 0, sizeof(rs485->padding));
916 	port->rs485 = *rs485;
917 
918 	schedule_work(&one->rs_work);
919 
920 	return 0;
921 }
922 
923 static int max310x_startup(struct uart_port *port)
924 {
925 	struct max310x_port *s = dev_get_drvdata(port->dev);
926 	unsigned int val;
927 
928 	s->devtype->power(port, 1);
929 
930 	/* Configure MODE1 register */
931 	max310x_port_update(port, MAX310X_MODE1_REG,
932 			    MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
933 
934 	/* Configure MODE2 register & Reset FIFOs*/
935 	val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
936 	max310x_port_write(port, MAX310X_MODE2_REG, val);
937 	max310x_port_update(port, MAX310X_MODE2_REG,
938 			    MAX310X_MODE2_FIFORST_BIT, 0);
939 
940 	/* Configure flow control levels */
941 	/* Flow control halt level 96, resume level 48 */
942 	max310x_port_write(port, MAX310X_FLOWLVL_REG,
943 			   MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
944 
945 	/* Clear IRQ status register */
946 	max310x_port_read(port, MAX310X_IRQSTS_REG);
947 
948 	/* Enable RX, TX, CTS change interrupts */
949 	val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
950 	max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
951 
952 	return 0;
953 }
954 
955 static void max310x_shutdown(struct uart_port *port)
956 {
957 	struct max310x_port *s = dev_get_drvdata(port->dev);
958 
959 	/* Disable all interrupts */
960 	max310x_port_write(port, MAX310X_IRQEN_REG, 0);
961 
962 	s->devtype->power(port, 0);
963 }
964 
965 static const char *max310x_type(struct uart_port *port)
966 {
967 	struct max310x_port *s = dev_get_drvdata(port->dev);
968 
969 	return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
970 }
971 
972 static int max310x_request_port(struct uart_port *port)
973 {
974 	/* Do nothing */
975 	return 0;
976 }
977 
978 static void max310x_config_port(struct uart_port *port, int flags)
979 {
980 	if (flags & UART_CONFIG_TYPE)
981 		port->type = PORT_MAX310X;
982 }
983 
984 static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
985 {
986 	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
987 		return -EINVAL;
988 	if (s->irq != port->irq)
989 		return -EINVAL;
990 
991 	return 0;
992 }
993 
994 static void max310x_null_void(struct uart_port *port)
995 {
996 	/* Do nothing */
997 }
998 
999 static const struct uart_ops max310x_ops = {
1000 	.tx_empty	= max310x_tx_empty,
1001 	.set_mctrl	= max310x_set_mctrl,
1002 	.get_mctrl	= max310x_get_mctrl,
1003 	.stop_tx	= max310x_null_void,
1004 	.start_tx	= max310x_start_tx,
1005 	.stop_rx	= max310x_null_void,
1006 	.break_ctl	= max310x_break_ctl,
1007 	.startup	= max310x_startup,
1008 	.shutdown	= max310x_shutdown,
1009 	.set_termios	= max310x_set_termios,
1010 	.type		= max310x_type,
1011 	.request_port	= max310x_request_port,
1012 	.release_port	= max310x_null_void,
1013 	.config_port	= max310x_config_port,
1014 	.verify_port	= max310x_verify_port,
1015 };
1016 
1017 static int __maybe_unused max310x_suspend(struct device *dev)
1018 {
1019 	struct max310x_port *s = dev_get_drvdata(dev);
1020 	int i;
1021 
1022 	for (i = 0; i < s->devtype->nr; i++) {
1023 		uart_suspend_port(&max310x_uart, &s->p[i].port);
1024 		s->devtype->power(&s->p[i].port, 0);
1025 	}
1026 
1027 	return 0;
1028 }
1029 
1030 static int __maybe_unused max310x_resume(struct device *dev)
1031 {
1032 	struct max310x_port *s = dev_get_drvdata(dev);
1033 	int i;
1034 
1035 	for (i = 0; i < s->devtype->nr; i++) {
1036 		s->devtype->power(&s->p[i].port, 1);
1037 		uart_resume_port(&max310x_uart, &s->p[i].port);
1038 	}
1039 
1040 	return 0;
1041 }
1042 
1043 static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
1044 
1045 #ifdef CONFIG_GPIOLIB
1046 static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset)
1047 {
1048 	unsigned int val;
1049 	struct max310x_port *s = gpiochip_get_data(chip);
1050 	struct uart_port *port = &s->p[offset / 4].port;
1051 
1052 	val = max310x_port_read(port, MAX310X_GPIODATA_REG);
1053 
1054 	return !!((val >> 4) & (1 << (offset % 4)));
1055 }
1056 
1057 static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
1058 {
1059 	struct max310x_port *s = gpiochip_get_data(chip);
1060 	struct uart_port *port = &s->p[offset / 4].port;
1061 
1062 	max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1063 			    value ? 1 << (offset % 4) : 0);
1064 }
1065 
1066 static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
1067 {
1068 	struct max310x_port *s = gpiochip_get_data(chip);
1069 	struct uart_port *port = &s->p[offset / 4].port;
1070 
1071 	max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
1072 
1073 	return 0;
1074 }
1075 
1076 static int max310x_gpio_direction_output(struct gpio_chip *chip,
1077 					 unsigned offset, int value)
1078 {
1079 	struct max310x_port *s = gpiochip_get_data(chip);
1080 	struct uart_port *port = &s->p[offset / 4].port;
1081 
1082 	max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1083 			    value ? 1 << (offset % 4) : 0);
1084 	max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
1085 			    1 << (offset % 4));
1086 
1087 	return 0;
1088 }
1089 #endif
1090 
1091 static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
1092 			 struct regmap *regmap, int irq, unsigned long flags)
1093 {
1094 	int i, ret, fmin, fmax, freq, uartclk;
1095 	struct clk *clk_osc, *clk_xtal;
1096 	struct max310x_port *s;
1097 	bool xtal = false;
1098 
1099 	if (IS_ERR(regmap))
1100 		return PTR_ERR(regmap);
1101 
1102 	/* Alloc port structure */
1103 	s = devm_kzalloc(dev, sizeof(*s) +
1104 			 sizeof(struct max310x_one) * devtype->nr, GFP_KERNEL);
1105 	if (!s) {
1106 		dev_err(dev, "Error allocating port structure\n");
1107 		return -ENOMEM;
1108 	}
1109 
1110 	clk_osc = devm_clk_get(dev, "osc");
1111 	clk_xtal = devm_clk_get(dev, "xtal");
1112 	if (!IS_ERR(clk_osc)) {
1113 		s->clk = clk_osc;
1114 		fmin = 500000;
1115 		fmax = 35000000;
1116 	} else if (!IS_ERR(clk_xtal)) {
1117 		s->clk = clk_xtal;
1118 		fmin = 1000000;
1119 		fmax = 4000000;
1120 		xtal = true;
1121 	} else if (PTR_ERR(clk_osc) == -EPROBE_DEFER ||
1122 		   PTR_ERR(clk_xtal) == -EPROBE_DEFER) {
1123 		return -EPROBE_DEFER;
1124 	} else {
1125 		dev_err(dev, "Cannot get clock\n");
1126 		return -EINVAL;
1127 	}
1128 
1129 	ret = clk_prepare_enable(s->clk);
1130 	if (ret)
1131 		return ret;
1132 
1133 	freq = clk_get_rate(s->clk);
1134 	/* Check frequency limits */
1135 	if (freq < fmin || freq > fmax) {
1136 		ret = -ERANGE;
1137 		goto out_clk;
1138 	}
1139 
1140 	s->regmap = regmap;
1141 	s->devtype = devtype;
1142 	dev_set_drvdata(dev, s);
1143 
1144 	/* Check device to ensure we are talking to what we expect */
1145 	ret = devtype->detect(dev);
1146 	if (ret)
1147 		goto out_clk;
1148 
1149 	for (i = 0; i < devtype->nr; i++) {
1150 		unsigned int offs = i << 5;
1151 
1152 		/* Reset port */
1153 		regmap_write(s->regmap, MAX310X_MODE2_REG + offs,
1154 			     MAX310X_MODE2_RST_BIT);
1155 		/* Clear port reset */
1156 		regmap_write(s->regmap, MAX310X_MODE2_REG + offs, 0);
1157 
1158 		/* Wait for port startup */
1159 		do {
1160 			regmap_read(s->regmap,
1161 				    MAX310X_BRGDIVLSB_REG + offs, &ret);
1162 		} while (ret != 0x01);
1163 
1164 		regmap_update_bits(s->regmap, MAX310X_MODE1_REG + offs,
1165 				   MAX310X_MODE1_AUTOSLEEP_BIT,
1166 				   MAX310X_MODE1_AUTOSLEEP_BIT);
1167 	}
1168 
1169 	uartclk = max310x_set_ref_clk(s, freq, xtal);
1170 	dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
1171 
1172 #ifdef CONFIG_GPIOLIB
1173 	/* Setup GPIO cotroller */
1174 	s->gpio.owner		= THIS_MODULE;
1175 	s->gpio.parent		= dev;
1176 	s->gpio.label		= dev_name(dev);
1177 	s->gpio.direction_input	= max310x_gpio_direction_input;
1178 	s->gpio.get		= max310x_gpio_get;
1179 	s->gpio.direction_output= max310x_gpio_direction_output;
1180 	s->gpio.set		= max310x_gpio_set;
1181 	s->gpio.base		= -1;
1182 	s->gpio.ngpio		= devtype->nr * 4;
1183 	s->gpio.can_sleep	= 1;
1184 	ret = devm_gpiochip_add_data(dev, &s->gpio, s);
1185 	if (ret)
1186 		goto out_clk;
1187 #endif
1188 
1189 	mutex_init(&s->mutex);
1190 
1191 	for (i = 0; i < devtype->nr; i++) {
1192 		unsigned int line;
1193 
1194 		line = find_first_zero_bit(max310x_lines, MAX310X_UART_NRMAX);
1195 		if (line == MAX310X_UART_NRMAX) {
1196 			ret = -ERANGE;
1197 			goto out_uart;
1198 		}
1199 
1200 		/* Initialize port data */
1201 		s->p[i].port.line	= line;
1202 		s->p[i].port.dev	= dev;
1203 		s->p[i].port.irq	= irq;
1204 		s->p[i].port.type	= PORT_MAX310X;
1205 		s->p[i].port.fifosize	= MAX310X_FIFO_SIZE;
1206 		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1207 		s->p[i].port.iotype	= UPIO_PORT;
1208 		s->p[i].port.iobase	= i * 0x20;
1209 		s->p[i].port.membase	= (void __iomem *)~0;
1210 		s->p[i].port.uartclk	= uartclk;
1211 		s->p[i].port.rs485_config = max310x_rs485_config;
1212 		s->p[i].port.ops	= &max310x_ops;
1213 		/* Disable all interrupts */
1214 		max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
1215 		/* Clear IRQ status register */
1216 		max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
1217 		/* Enable IRQ pin */
1218 		max310x_port_update(&s->p[i].port, MAX310X_MODE1_REG,
1219 				    MAX310X_MODE1_IRQSEL_BIT,
1220 				    MAX310X_MODE1_IRQSEL_BIT);
1221 		/* Initialize queue for start TX */
1222 		INIT_WORK(&s->p[i].tx_work, max310x_wq_proc);
1223 		/* Initialize queue for changing LOOPBACK mode */
1224 		INIT_WORK(&s->p[i].md_work, max310x_md_proc);
1225 		/* Initialize queue for changing RS485 mode */
1226 		INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
1227 
1228 		/* Register port */
1229 		ret = uart_add_one_port(&max310x_uart, &s->p[i].port);
1230 		if (ret) {
1231 			s->p[i].port.dev = NULL;
1232 			goto out_uart;
1233 		}
1234 		set_bit(line, max310x_lines);
1235 
1236 		/* Go to suspend mode */
1237 		devtype->power(&s->p[i].port, 0);
1238 	}
1239 
1240 	/* Setup interrupt */
1241 	ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
1242 					IRQF_ONESHOT | flags, dev_name(dev), s);
1243 	if (!ret)
1244 		return 0;
1245 
1246 	dev_err(dev, "Unable to reguest IRQ %i\n", irq);
1247 
1248 out_uart:
1249 	for (i = 0; i < devtype->nr; i++) {
1250 		if (s->p[i].port.dev) {
1251 			uart_remove_one_port(&max310x_uart, &s->p[i].port);
1252 			clear_bit(s->p[i].port.line, max310x_lines);
1253 		}
1254 	}
1255 
1256 	mutex_destroy(&s->mutex);
1257 
1258 out_clk:
1259 	clk_disable_unprepare(s->clk);
1260 
1261 	return ret;
1262 }
1263 
1264 static int max310x_remove(struct device *dev)
1265 {
1266 	struct max310x_port *s = dev_get_drvdata(dev);
1267 	int i;
1268 
1269 	for (i = 0; i < s->devtype->nr; i++) {
1270 		cancel_work_sync(&s->p[i].tx_work);
1271 		cancel_work_sync(&s->p[i].md_work);
1272 		cancel_work_sync(&s->p[i].rs_work);
1273 		uart_remove_one_port(&max310x_uart, &s->p[i].port);
1274 		clear_bit(s->p[i].port.line, max310x_lines);
1275 		s->devtype->power(&s->p[i].port, 0);
1276 	}
1277 
1278 	mutex_destroy(&s->mutex);
1279 	clk_disable_unprepare(s->clk);
1280 
1281 	return 0;
1282 }
1283 
1284 static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
1285 	{ .compatible = "maxim,max3107",	.data = &max3107_devtype, },
1286 	{ .compatible = "maxim,max3108",	.data = &max3108_devtype, },
1287 	{ .compatible = "maxim,max3109",	.data = &max3109_devtype, },
1288 	{ .compatible = "maxim,max14830",	.data = &max14830_devtype },
1289 	{ }
1290 };
1291 MODULE_DEVICE_TABLE(of, max310x_dt_ids);
1292 
1293 static struct regmap_config regcfg = {
1294 	.reg_bits = 8,
1295 	.val_bits = 8,
1296 	.write_flag_mask = 0x80,
1297 	.cache_type = REGCACHE_RBTREE,
1298 	.writeable_reg = max310x_reg_writeable,
1299 	.volatile_reg = max310x_reg_volatile,
1300 	.precious_reg = max310x_reg_precious,
1301 };
1302 
1303 #ifdef CONFIG_SPI_MASTER
1304 static int max310x_spi_probe(struct spi_device *spi)
1305 {
1306 	struct max310x_devtype *devtype;
1307 	unsigned long flags = 0;
1308 	struct regmap *regmap;
1309 	int ret;
1310 
1311 	/* Setup SPI bus */
1312 	spi->bits_per_word	= 8;
1313 	spi->mode		= spi->mode ? : SPI_MODE_0;
1314 	spi->max_speed_hz	= spi->max_speed_hz ? : 26000000;
1315 	ret = spi_setup(spi);
1316 	if (ret)
1317 		return ret;
1318 
1319 	if (spi->dev.of_node) {
1320 		const struct of_device_id *of_id =
1321 			of_match_device(max310x_dt_ids, &spi->dev);
1322 
1323 		devtype = (struct max310x_devtype *)of_id->data;
1324 	} else {
1325 		const struct spi_device_id *id_entry = spi_get_device_id(spi);
1326 
1327 		devtype = (struct max310x_devtype *)id_entry->driver_data;
1328 	}
1329 
1330 	flags = IRQF_TRIGGER_FALLING;
1331 	regcfg.max_register = devtype->nr * 0x20 - 1;
1332 	regmap = devm_regmap_init_spi(spi, &regcfg);
1333 
1334 	return max310x_probe(&spi->dev, devtype, regmap, spi->irq, flags);
1335 }
1336 
1337 static int max310x_spi_remove(struct spi_device *spi)
1338 {
1339 	return max310x_remove(&spi->dev);
1340 }
1341 
1342 static const struct spi_device_id max310x_id_table[] = {
1343 	{ "max3107",	(kernel_ulong_t)&max3107_devtype, },
1344 	{ "max3108",	(kernel_ulong_t)&max3108_devtype, },
1345 	{ "max3109",	(kernel_ulong_t)&max3109_devtype, },
1346 	{ "max14830",	(kernel_ulong_t)&max14830_devtype, },
1347 	{ }
1348 };
1349 MODULE_DEVICE_TABLE(spi, max310x_id_table);
1350 
1351 static struct spi_driver max310x_spi_driver = {
1352 	.driver = {
1353 		.name		= MAX310X_NAME,
1354 		.of_match_table	= of_match_ptr(max310x_dt_ids),
1355 		.pm		= &max310x_pm_ops,
1356 	},
1357 	.probe		= max310x_spi_probe,
1358 	.remove		= max310x_spi_remove,
1359 	.id_table	= max310x_id_table,
1360 };
1361 #endif
1362 
1363 static int __init max310x_uart_init(void)
1364 {
1365 	int ret;
1366 
1367 	bitmap_zero(max310x_lines, MAX310X_UART_NRMAX);
1368 
1369 	ret = uart_register_driver(&max310x_uart);
1370 	if (ret)
1371 		return ret;
1372 
1373 #ifdef CONFIG_SPI_MASTER
1374 	spi_register_driver(&max310x_spi_driver);
1375 #endif
1376 
1377 	return 0;
1378 }
1379 module_init(max310x_uart_init);
1380 
1381 static void __exit max310x_uart_exit(void)
1382 {
1383 #ifdef CONFIG_SPI_MASTER
1384 	spi_unregister_driver(&max310x_spi_driver);
1385 #endif
1386 
1387 	uart_unregister_driver(&max310x_uart);
1388 }
1389 module_exit(max310x_uart_exit);
1390 
1391 MODULE_LICENSE("GPL");
1392 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1393 MODULE_DESCRIPTION("MAX310X serial driver");
1394