2 * Maxim (Dallas) MAX3107/8/9, MAX14830 serial driver
4 * Copyright (C) 2012-2014 Alexander Shiyan <shc_work@mail.ru>
6 * Based on max3100.c, by Christian Pellegrin <chripell@evolware.org>
7 * Based on max3110.c, by Feng Tang <feng.tang@intel.com>
8 * Based on max3107.c, by Aavamobile
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
16 #include <linux/module.h>
17 #include <linux/delay.h>
18 #include <linux/device.h>
19 #include <linux/bitops.h>
20 #include <linux/clk.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/regmap.h>
26 #include <linux/gpio.h>
27 #include <linux/spi/spi.h>
29 #include <linux/platform_data/max310x.h>
31 #define MAX310X_NAME "max310x"
32 #define MAX310X_MAJOR 204
33 #define MAX310X_MINOR 209
35 /* MAX310X register definitions */
36 #define MAX310X_RHR_REG (0x00) /* RX FIFO */
37 #define MAX310X_THR_REG (0x00) /* TX FIFO */
38 #define MAX310X_IRQEN_REG (0x01) /* IRQ enable */
39 #define MAX310X_IRQSTS_REG (0x02) /* IRQ status */
40 #define MAX310X_LSR_IRQEN_REG (0x03) /* LSR IRQ enable */
41 #define MAX310X_LSR_IRQSTS_REG (0x04) /* LSR IRQ status */
42 #define MAX310X_REG_05 (0x05)
43 #define MAX310X_SPCHR_IRQEN_REG MAX310X_REG_05 /* Special char IRQ en */
44 #define MAX310X_SPCHR_IRQSTS_REG (0x06) /* Special char IRQ status */
45 #define MAX310X_STS_IRQEN_REG (0x07) /* Status IRQ enable */
46 #define MAX310X_STS_IRQSTS_REG (0x08) /* Status IRQ status */
47 #define MAX310X_MODE1_REG (0x09) /* MODE1 */
48 #define MAX310X_MODE2_REG (0x0a) /* MODE2 */
49 #define MAX310X_LCR_REG (0x0b) /* LCR */
50 #define MAX310X_RXTO_REG (0x0c) /* RX timeout */
51 #define MAX310X_HDPIXDELAY_REG (0x0d) /* Auto transceiver delays */
52 #define MAX310X_IRDA_REG (0x0e) /* IRDA settings */
53 #define MAX310X_FLOWLVL_REG (0x0f) /* Flow control levels */
54 #define MAX310X_FIFOTRIGLVL_REG (0x10) /* FIFO IRQ trigger levels */
55 #define MAX310X_TXFIFOLVL_REG (0x11) /* TX FIFO level */
56 #define MAX310X_RXFIFOLVL_REG (0x12) /* RX FIFO level */
57 #define MAX310X_FLOWCTRL_REG (0x13) /* Flow control */
58 #define MAX310X_XON1_REG (0x14) /* XON1 character */
59 #define MAX310X_XON2_REG (0x15) /* XON2 character */
60 #define MAX310X_XOFF1_REG (0x16) /* XOFF1 character */
61 #define MAX310X_XOFF2_REG (0x17) /* XOFF2 character */
62 #define MAX310X_GPIOCFG_REG (0x18) /* GPIO config */
63 #define MAX310X_GPIODATA_REG (0x19) /* GPIO data */
64 #define MAX310X_PLLCFG_REG (0x1a) /* PLL config */
65 #define MAX310X_BRGCFG_REG (0x1b) /* Baud rate generator conf */
66 #define MAX310X_BRGDIVLSB_REG (0x1c) /* Baud rate divisor LSB */
67 #define MAX310X_BRGDIVMSB_REG (0x1d) /* Baud rate divisor MSB */
68 #define MAX310X_CLKSRC_REG (0x1e) /* Clock source */
69 #define MAX310X_REG_1F (0x1f)
71 #define MAX310X_REVID_REG MAX310X_REG_1F /* Revision ID */
73 #define MAX310X_GLOBALIRQ_REG MAX310X_REG_1F /* Global IRQ (RO) */
74 #define MAX310X_GLOBALCMD_REG MAX310X_REG_1F /* Global Command (WO) */
76 /* Extended registers */
77 #define MAX310X_REVID_EXTREG MAX310X_REG_05 /* Revision ID */
79 /* IRQ register bits */
80 #define MAX310X_IRQ_LSR_BIT (1 << 0) /* LSR interrupt */
81 #define MAX310X_IRQ_SPCHR_BIT (1 << 1) /* Special char interrupt */
82 #define MAX310X_IRQ_STS_BIT (1 << 2) /* Status interrupt */
83 #define MAX310X_IRQ_RXFIFO_BIT (1 << 3) /* RX FIFO interrupt */
84 #define MAX310X_IRQ_TXFIFO_BIT (1 << 4) /* TX FIFO interrupt */
85 #define MAX310X_IRQ_TXEMPTY_BIT (1 << 5) /* TX FIFO empty interrupt */
86 #define MAX310X_IRQ_RXEMPTY_BIT (1 << 6) /* RX FIFO empty interrupt */
87 #define MAX310X_IRQ_CTS_BIT (1 << 7) /* CTS interrupt */
89 /* LSR register bits */
90 #define MAX310X_LSR_RXTO_BIT (1 << 0) /* RX timeout */
91 #define MAX310X_LSR_RXOVR_BIT (1 << 1) /* RX overrun */
92 #define MAX310X_LSR_RXPAR_BIT (1 << 2) /* RX parity error */
93 #define MAX310X_LSR_FRERR_BIT (1 << 3) /* Frame error */
94 #define MAX310X_LSR_RXBRK_BIT (1 << 4) /* RX break */
95 #define MAX310X_LSR_RXNOISE_BIT (1 << 5) /* RX noise */
96 #define MAX310X_LSR_CTS_BIT (1 << 7) /* CTS pin state */
98 /* Special character register bits */
99 #define MAX310X_SPCHR_XON1_BIT (1 << 0) /* XON1 character */
100 #define MAX310X_SPCHR_XON2_BIT (1 << 1) /* XON2 character */
101 #define MAX310X_SPCHR_XOFF1_BIT (1 << 2) /* XOFF1 character */
102 #define MAX310X_SPCHR_XOFF2_BIT (1 << 3) /* XOFF2 character */
103 #define MAX310X_SPCHR_BREAK_BIT (1 << 4) /* RX break */
104 #define MAX310X_SPCHR_MULTIDROP_BIT (1 << 5) /* 9-bit multidrop addr char */
106 /* Status register bits */
107 #define MAX310X_STS_GPIO0_BIT (1 << 0) /* GPIO 0 interrupt */
108 #define MAX310X_STS_GPIO1_BIT (1 << 1) /* GPIO 1 interrupt */
109 #define MAX310X_STS_GPIO2_BIT (1 << 2) /* GPIO 2 interrupt */
110 #define MAX310X_STS_GPIO3_BIT (1 << 3) /* GPIO 3 interrupt */
111 #define MAX310X_STS_CLKREADY_BIT (1 << 5) /* Clock ready */
112 #define MAX310X_STS_SLEEP_BIT (1 << 6) /* Sleep interrupt */
114 /* MODE1 register bits */
115 #define MAX310X_MODE1_RXDIS_BIT (1 << 0) /* RX disable */
116 #define MAX310X_MODE1_TXDIS_BIT (1 << 1) /* TX disable */
117 #define MAX310X_MODE1_TXHIZ_BIT (1 << 2) /* TX pin three-state */
118 #define MAX310X_MODE1_RTSHIZ_BIT (1 << 3) /* RTS pin three-state */
119 #define MAX310X_MODE1_TRNSCVCTRL_BIT (1 << 4) /* Transceiver ctrl enable */
120 #define MAX310X_MODE1_FORCESLEEP_BIT (1 << 5) /* Force sleep mode */
121 #define MAX310X_MODE1_AUTOSLEEP_BIT (1 << 6) /* Auto sleep enable */
122 #define MAX310X_MODE1_IRQSEL_BIT (1 << 7) /* IRQ pin enable */
124 /* MODE2 register bits */
125 #define MAX310X_MODE2_RST_BIT (1 << 0) /* Chip reset */
126 #define MAX310X_MODE2_FIFORST_BIT (1 << 1) /* FIFO reset */
127 #define MAX310X_MODE2_RXTRIGINV_BIT (1 << 2) /* RX FIFO INT invert */
128 #define MAX310X_MODE2_RXEMPTINV_BIT (1 << 3) /* RX FIFO empty INT invert */
129 #define MAX310X_MODE2_SPCHR_BIT (1 << 4) /* Special chr detect enable */
130 #define MAX310X_MODE2_LOOPBACK_BIT (1 << 5) /* Internal loopback enable */
131 #define MAX310X_MODE2_MULTIDROP_BIT (1 << 6) /* 9-bit multidrop enable */
132 #define MAX310X_MODE2_ECHOSUPR_BIT (1 << 7) /* ECHO suppression enable */
134 /* LCR register bits */
135 #define MAX310X_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */
136 #define MAX310X_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1
138 * Word length bits table:
144 #define MAX310X_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
146 * STOP length bit table:
148 * 1 -> 1-1.5 stop bits if
150 * 2 stop bits otherwise
152 #define MAX310X_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */
153 #define MAX310X_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */
154 #define MAX310X_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */
155 #define MAX310X_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */
156 #define MAX310X_LCR_RTS_BIT (1 << 7) /* RTS pin control */
157 #define MAX310X_LCR_WORD_LEN_5 (0x00)
158 #define MAX310X_LCR_WORD_LEN_6 (0x01)
159 #define MAX310X_LCR_WORD_LEN_7 (0x02)
160 #define MAX310X_LCR_WORD_LEN_8 (0x03)
162 /* IRDA register bits */
163 #define MAX310X_IRDA_IRDAEN_BIT (1 << 0) /* IRDA mode enable */
164 #define MAX310X_IRDA_SIR_BIT (1 << 1) /* SIR mode enable */
165 #define MAX310X_IRDA_SHORTIR_BIT (1 << 2) /* Short SIR mode enable */
166 #define MAX310X_IRDA_MIR_BIT (1 << 3) /* MIR mode enable */
167 #define MAX310X_IRDA_RXINV_BIT (1 << 4) /* RX logic inversion enable */
168 #define MAX310X_IRDA_TXINV_BIT (1 << 5) /* TX logic inversion enable */
170 /* Flow control trigger level register masks */
171 #define MAX310X_FLOWLVL_HALT_MASK (0x000f) /* Flow control halt level */
172 #define MAX310X_FLOWLVL_RES_MASK (0x00f0) /* Flow control resume level */
173 #define MAX310X_FLOWLVL_HALT(words) ((words / 8) & 0x0f)
174 #define MAX310X_FLOWLVL_RES(words) (((words / 8) & 0x0f) << 4)
176 /* FIFO interrupt trigger level register masks */
177 #define MAX310X_FIFOTRIGLVL_TX_MASK (0x0f) /* TX FIFO trigger level */
178 #define MAX310X_FIFOTRIGLVL_RX_MASK (0xf0) /* RX FIFO trigger level */
179 #define MAX310X_FIFOTRIGLVL_TX(words) ((words / 8) & 0x0f)
180 #define MAX310X_FIFOTRIGLVL_RX(words) (((words / 8) & 0x0f) << 4)
182 /* Flow control register bits */
183 #define MAX310X_FLOWCTRL_AUTORTS_BIT (1 << 0) /* Auto RTS flow ctrl enable */
184 #define MAX310X_FLOWCTRL_AUTOCTS_BIT (1 << 1) /* Auto CTS flow ctrl enable */
185 #define MAX310X_FLOWCTRL_GPIADDR_BIT (1 << 2) /* Enables that GPIO inputs
186 * are used in conjunction with
187 * XOFF2 for definition of
188 * special character */
189 #define MAX310X_FLOWCTRL_SWFLOWEN_BIT (1 << 3) /* Auto SW flow ctrl enable */
190 #define MAX310X_FLOWCTRL_SWFLOW0_BIT (1 << 4) /* SWFLOW bit 0 */
191 #define MAX310X_FLOWCTRL_SWFLOW1_BIT (1 << 5) /* SWFLOW bit 1
193 * SWFLOW bits 1 & 0 table:
194 * 00 -> no transmitter flow
196 * 01 -> receiver compares
200 * 10 -> receiver compares
204 * 11 -> receiver compares
205 * XON1, XON2, XOFF1 and
209 #define MAX310X_FLOWCTRL_SWFLOW2_BIT (1 << 6) /* SWFLOW bit 2 */
210 #define MAX310X_FLOWCTRL_SWFLOW3_BIT (1 << 7) /* SWFLOW bit 3
212 * SWFLOW bits 3 & 2 table:
213 * 00 -> no received flow
215 * 01 -> transmitter generates
217 * 10 -> transmitter generates
219 * 11 -> transmitter generates
220 * XON1, XON2, XOFF1 and
224 /* GPIO configuration register bits */
225 #define MAX310X_GPIOCFG_GP0OUT_BIT (1 << 0) /* GPIO 0 output enable */
226 #define MAX310X_GPIOCFG_GP1OUT_BIT (1 << 1) /* GPIO 1 output enable */
227 #define MAX310X_GPIOCFG_GP2OUT_BIT (1 << 2) /* GPIO 2 output enable */
228 #define MAX310X_GPIOCFG_GP3OUT_BIT (1 << 3) /* GPIO 3 output enable */
229 #define MAX310X_GPIOCFG_GP0OD_BIT (1 << 4) /* GPIO 0 open-drain enable */
230 #define MAX310X_GPIOCFG_GP1OD_BIT (1 << 5) /* GPIO 1 open-drain enable */
231 #define MAX310X_GPIOCFG_GP2OD_BIT (1 << 6) /* GPIO 2 open-drain enable */
232 #define MAX310X_GPIOCFG_GP3OD_BIT (1 << 7) /* GPIO 3 open-drain enable */
234 /* GPIO DATA register bits */
235 #define MAX310X_GPIODATA_GP0OUT_BIT (1 << 0) /* GPIO 0 output value */
236 #define MAX310X_GPIODATA_GP1OUT_BIT (1 << 1) /* GPIO 1 output value */
237 #define MAX310X_GPIODATA_GP2OUT_BIT (1 << 2) /* GPIO 2 output value */
238 #define MAX310X_GPIODATA_GP3OUT_BIT (1 << 3) /* GPIO 3 output value */
239 #define MAX310X_GPIODATA_GP0IN_BIT (1 << 4) /* GPIO 0 input value */
240 #define MAX310X_GPIODATA_GP1IN_BIT (1 << 5) /* GPIO 1 input value */
241 #define MAX310X_GPIODATA_GP2IN_BIT (1 << 6) /* GPIO 2 input value */
242 #define MAX310X_GPIODATA_GP3IN_BIT (1 << 7) /* GPIO 3 input value */
244 /* PLL configuration register masks */
245 #define MAX310X_PLLCFG_PREDIV_MASK (0x3f) /* PLL predivision value */
246 #define MAX310X_PLLCFG_PLLFACTOR_MASK (0xc0) /* PLL multiplication factor */
248 /* Baud rate generator configuration register bits */
249 #define MAX310X_BRGCFG_2XMODE_BIT (1 << 4) /* Double baud rate */
250 #define MAX310X_BRGCFG_4XMODE_BIT (1 << 5) /* Quadruple baud rate */
252 /* Clock source register bits */
253 #define MAX310X_CLKSRC_CRYST_BIT (1 << 1) /* Crystal osc enable */
254 #define MAX310X_CLKSRC_PLL_BIT (1 << 2) /* PLL enable */
255 #define MAX310X_CLKSRC_PLLBYP_BIT (1 << 3) /* PLL bypass */
256 #define MAX310X_CLKSRC_EXTCLK_BIT (1 << 4) /* External clock enable */
257 #define MAX310X_CLKSRC_CLK2RTS_BIT (1 << 7) /* Baud clk to RTS pin */
259 /* Global commands */
260 #define MAX310X_EXTREG_ENBL (0xce)
261 #define MAX310X_EXTREG_DSBL (0xcd)
263 /* Misc definitions */
264 #define MAX310X_FIFO_SIZE (128)
265 #define MAX310x_REV_MASK (0xfc)
267 /* MAX3107 specific */
268 #define MAX3107_REV_ID (0xa0)
270 /* MAX3109 specific */
271 #define MAX3109_REV_ID (0xc0)
273 /* MAX14830 specific */
274 #define MAX14830_BRGCFG_CLKDIS_BIT (1 << 6) /* Clock Disable */
275 #define MAX14830_REV_ID (0xb0)
277 struct max310x_devtype {
280 int (*detect)(struct device *);
281 void (*power)(struct uart_port *, int);
285 struct uart_port port;
286 struct work_struct tx_work;
287 struct work_struct md_work;
290 struct max310x_port {
291 struct uart_driver uart;
292 struct max310x_devtype *devtype;
293 struct regmap *regmap;
296 struct max310x_pdata *pdata;
298 #ifdef CONFIG_GPIOLIB
299 struct gpio_chip gpio;
301 struct max310x_one p[0];
304 static u8 max310x_port_read(struct uart_port *port, u8 reg)
306 struct max310x_port *s = dev_get_drvdata(port->dev);
307 unsigned int val = 0;
309 regmap_read(s->regmap, port->iobase + reg, &val);
314 static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
316 struct max310x_port *s = dev_get_drvdata(port->dev);
318 regmap_write(s->regmap, port->iobase + reg, val);
321 static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
323 struct max310x_port *s = dev_get_drvdata(port->dev);
325 regmap_update_bits(s->regmap, port->iobase + reg, mask, val);
328 static int max3107_detect(struct device *dev)
330 struct max310x_port *s = dev_get_drvdata(dev);
331 unsigned int val = 0;
334 ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val);
338 if (((val & MAX310x_REV_MASK) != MAX3107_REV_ID)) {
340 "%s ID 0x%02x does not match\n", s->devtype->name, val);
347 static int max3108_detect(struct device *dev)
349 struct max310x_port *s = dev_get_drvdata(dev);
350 unsigned int val = 0;
353 /* MAX3108 have not REV ID register, we just check default value
354 * from clocksource register to make sure everything works.
356 ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val);
360 if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) {
361 dev_err(dev, "%s not present\n", s->devtype->name);
368 static int max3109_detect(struct device *dev)
370 struct max310x_port *s = dev_get_drvdata(dev);
371 unsigned int val = 0;
374 ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val);
378 if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
380 "%s ID 0x%02x does not match\n", s->devtype->name, val);
387 static void max310x_power(struct uart_port *port, int on)
389 max310x_port_update(port, MAX310X_MODE1_REG,
390 MAX310X_MODE1_FORCESLEEP_BIT,
391 on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT);
396 static int max14830_detect(struct device *dev)
398 struct max310x_port *s = dev_get_drvdata(dev);
399 unsigned int val = 0;
402 ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
403 MAX310X_EXTREG_ENBL);
407 regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
408 regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
409 if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
411 "%s ID 0x%02x does not match\n", s->devtype->name, val);
418 static void max14830_power(struct uart_port *port, int on)
420 max310x_port_update(port, MAX310X_BRGCFG_REG,
421 MAX14830_BRGCFG_CLKDIS_BIT,
422 on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT);
427 static const struct max310x_devtype max3107_devtype = {
430 .detect = max3107_detect,
431 .power = max310x_power,
434 static const struct max310x_devtype max3108_devtype = {
437 .detect = max3108_detect,
438 .power = max310x_power,
441 static const struct max310x_devtype max3109_devtype = {
444 .detect = max3109_detect,
445 .power = max310x_power,
448 static const struct max310x_devtype max14830_devtype = {
451 .detect = max14830_detect,
452 .power = max14830_power,
455 static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
457 switch (reg & 0x1f) {
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:
472 static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
474 switch (reg & 0x1f) {
475 case MAX310X_RHR_REG:
476 case MAX310X_IRQSTS_REG:
477 case MAX310X_LSR_IRQSTS_REG:
478 case MAX310X_SPCHR_IRQSTS_REG:
479 case MAX310X_STS_IRQSTS_REG:
480 case MAX310X_TXFIFOLVL_REG:
481 case MAX310X_RXFIFOLVL_REG:
482 case MAX310X_GPIODATA_REG:
483 case MAX310X_BRGDIVLSB_REG:
494 static bool max310x_reg_precious(struct device *dev, unsigned int reg)
496 switch (reg & 0x1f) {
497 case MAX310X_RHR_REG:
498 case MAX310X_IRQSTS_REG:
499 case MAX310X_SPCHR_IRQSTS_REG:
500 case MAX310X_STS_IRQSTS_REG:
509 static int max310x_set_baud(struct uart_port *port, int baud)
511 unsigned int mode = 0, clk = port->uartclk, div = clk / baud;
513 /* Check for minimal value for divider */
517 if (clk % baud && (div / 16) < 0x8000) {
519 mode = MAX310X_BRGCFG_2XMODE_BIT;
520 clk = port->uartclk * 2;
523 if (clk % baud && (div / 16) < 0x8000) {
525 mode = MAX310X_BRGCFG_4XMODE_BIT;
526 clk = port->uartclk * 4;
531 max310x_port_write(port, MAX310X_BRGDIVMSB_REG, (div / 16) >> 8);
532 max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div / 16);
533 max310x_port_write(port, MAX310X_BRGCFG_REG, (div % 16) | mode);
535 return DIV_ROUND_CLOSEST(clk, div);
538 static int max310x_update_best_err(unsigned long f, long *besterr)
540 /* Use baudrate 115200 for calculate error */
541 long err = f % (115200 * 16);
543 if ((*besterr < 0) || (*besterr > err)) {
551 static int max310x_set_ref_clk(struct max310x_port *s, unsigned long freq,
554 unsigned int div, clksrc, pllcfg = 0;
556 unsigned long fdiv, fmul, bestfreq = freq;
558 /* First, update error without PLL */
559 max310x_update_best_err(freq, &besterr);
561 /* Try all possible PLL dividers */
562 for (div = 1; (div <= 63) && besterr; div++) {
563 fdiv = DIV_ROUND_CLOSEST(freq, div);
565 /* Try multiplier 6 */
567 if ((fdiv >= 500000) && (fdiv <= 800000))
568 if (!max310x_update_best_err(fmul, &besterr)) {
569 pllcfg = (0 << 6) | div;
572 /* Try multiplier 48 */
574 if ((fdiv >= 850000) && (fdiv <= 1200000))
575 if (!max310x_update_best_err(fmul, &besterr)) {
576 pllcfg = (1 << 6) | div;
579 /* Try multiplier 96 */
581 if ((fdiv >= 425000) && (fdiv <= 1000000))
582 if (!max310x_update_best_err(fmul, &besterr)) {
583 pllcfg = (2 << 6) | div;
586 /* Try multiplier 144 */
588 if ((fdiv >= 390000) && (fdiv <= 667000))
589 if (!max310x_update_best_err(fmul, &besterr)) {
590 pllcfg = (3 << 6) | div;
595 /* Configure clock source */
596 clksrc = xtal ? MAX310X_CLKSRC_CRYST_BIT : MAX310X_CLKSRC_EXTCLK_BIT;
600 clksrc |= MAX310X_CLKSRC_PLL_BIT;
601 regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
603 clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
605 regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
607 /* Wait for crystal */
611 return (int)bestfreq;
614 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
616 unsigned int sts, ch, flag;
618 if (unlikely(rxlen >= port->fifosize)) {
619 dev_warn_ratelimited(port->dev,
620 "Port %i: Possible RX FIFO overrun\n",
622 port->icount.buf_overrun++;
623 /* Ensure sanity of RX level */
624 rxlen = port->fifosize;
628 ch = max310x_port_read(port, MAX310X_RHR_REG);
629 sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
631 sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT |
632 MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT;
638 if (sts & MAX310X_LSR_RXBRK_BIT) {
640 if (uart_handle_break(port))
642 } else if (sts & MAX310X_LSR_RXPAR_BIT)
643 port->icount.parity++;
644 else if (sts & MAX310X_LSR_FRERR_BIT)
645 port->icount.frame++;
646 else if (sts & MAX310X_LSR_RXOVR_BIT)
647 port->icount.overrun++;
649 sts &= port->read_status_mask;
650 if (sts & MAX310X_LSR_RXBRK_BIT)
652 else if (sts & MAX310X_LSR_RXPAR_BIT)
654 else if (sts & MAX310X_LSR_FRERR_BIT)
656 else if (sts & MAX310X_LSR_RXOVR_BIT)
660 if (uart_handle_sysrq_char(port, ch))
663 if (sts & port->ignore_status_mask)
666 uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag);
669 tty_flip_buffer_push(&port->state->port);
672 static void max310x_handle_tx(struct uart_port *port)
674 struct circ_buf *xmit = &port->state->xmit;
675 unsigned int txlen, to_send;
677 if (unlikely(port->x_char)) {
678 max310x_port_write(port, MAX310X_THR_REG, port->x_char);
684 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
687 /* Get length of data pending in circular buffer */
688 to_send = uart_circ_chars_pending(xmit);
689 if (likely(to_send)) {
690 /* Limit to size of TX FIFO */
691 txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
692 txlen = port->fifosize - txlen;
693 to_send = (to_send > txlen) ? txlen : to_send;
695 /* Add data to send */
696 port->icount.tx += to_send;
698 max310x_port_write(port, MAX310X_THR_REG,
699 xmit->buf[xmit->tail]);
700 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
704 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
705 uart_write_wakeup(port);
708 static void max310x_port_irq(struct max310x_port *s, int portno)
710 struct uart_port *port = &s->p[portno].port;
713 unsigned int ists, lsr, rxlen;
715 /* Read IRQ status & RX FIFO level */
716 ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
717 rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
721 if (ists & MAX310X_IRQ_CTS_BIT) {
722 lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
723 uart_handle_cts_change(port,
724 !!(lsr & MAX310X_LSR_CTS_BIT));
727 max310x_handle_rx(port, rxlen);
728 if (ists & MAX310X_IRQ_TXEMPTY_BIT) {
729 mutex_lock(&s->mutex);
730 max310x_handle_tx(port);
731 mutex_unlock(&s->mutex);
736 static irqreturn_t max310x_ist(int irq, void *dev_id)
738 struct max310x_port *s = (struct max310x_port *)dev_id;
740 if (s->uart.nr > 1) {
742 unsigned int val = ~0;
744 WARN_ON_ONCE(regmap_read(s->regmap,
745 MAX310X_GLOBALIRQ_REG, &val));
746 val = ((1 << s->uart.nr) - 1) & ~val;
749 max310x_port_irq(s, fls(val) - 1);
752 max310x_port_irq(s, 0);
757 static void max310x_wq_proc(struct work_struct *ws)
759 struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
760 struct max310x_port *s = dev_get_drvdata(one->port.dev);
762 mutex_lock(&s->mutex);
763 max310x_handle_tx(&one->port);
764 mutex_unlock(&s->mutex);
767 static void max310x_start_tx(struct uart_port *port)
769 struct max310x_one *one = container_of(port, struct max310x_one, port);
771 if (!work_pending(&one->tx_work))
772 schedule_work(&one->tx_work);
775 static unsigned int max310x_tx_empty(struct uart_port *port)
777 unsigned int lvl, sts;
779 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
780 sts = max310x_port_read(port, MAX310X_IRQSTS_REG);
782 return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0;
785 static unsigned int max310x_get_mctrl(struct uart_port *port)
787 /* DCD and DSR are not wired and CTS/RTS is handled automatically
788 * so just indicate DSR and CAR asserted
790 return TIOCM_DSR | TIOCM_CAR;
793 static void max310x_md_proc(struct work_struct *ws)
795 struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
797 max310x_port_update(&one->port, MAX310X_MODE2_REG,
798 MAX310X_MODE2_LOOPBACK_BIT,
799 (one->port.mctrl & TIOCM_LOOP) ?
800 MAX310X_MODE2_LOOPBACK_BIT : 0);
803 static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
805 struct max310x_one *one = container_of(port, struct max310x_one, port);
807 schedule_work(&one->md_work);
810 static void max310x_break_ctl(struct uart_port *port, int break_state)
812 max310x_port_update(port, MAX310X_LCR_REG,
813 MAX310X_LCR_TXBREAK_BIT,
814 break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
817 static void max310x_set_termios(struct uart_port *port,
818 struct ktermios *termios,
819 struct ktermios *old)
821 unsigned int lcr, flow = 0;
824 /* Mask termios capabilities we don't support */
825 termios->c_cflag &= ~CMSPAR;
828 switch (termios->c_cflag & CSIZE) {
830 lcr = MAX310X_LCR_WORD_LEN_5;
833 lcr = MAX310X_LCR_WORD_LEN_6;
836 lcr = MAX310X_LCR_WORD_LEN_7;
840 lcr = MAX310X_LCR_WORD_LEN_8;
845 if (termios->c_cflag & PARENB) {
846 lcr |= MAX310X_LCR_PARITY_BIT;
847 if (!(termios->c_cflag & PARODD))
848 lcr |= MAX310X_LCR_EVENPARITY_BIT;
852 if (termios->c_cflag & CSTOPB)
853 lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
855 /* Update LCR register */
856 max310x_port_write(port, MAX310X_LCR_REG, lcr);
858 /* Set read status mask */
859 port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
860 if (termios->c_iflag & INPCK)
861 port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
862 MAX310X_LSR_FRERR_BIT;
863 if (termios->c_iflag & (BRKINT | PARMRK))
864 port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
866 /* Set status ignore mask */
867 port->ignore_status_mask = 0;
868 if (termios->c_iflag & IGNBRK)
869 port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
870 if (!(termios->c_cflag & CREAD))
871 port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
872 MAX310X_LSR_RXOVR_BIT |
873 MAX310X_LSR_FRERR_BIT |
874 MAX310X_LSR_RXBRK_BIT;
876 /* Configure flow control */
877 max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
878 max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
879 if (termios->c_cflag & CRTSCTS)
880 flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
881 MAX310X_FLOWCTRL_AUTORTS_BIT;
882 if (termios->c_iflag & IXON)
883 flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
884 MAX310X_FLOWCTRL_SWFLOWEN_BIT;
885 if (termios->c_iflag & IXOFF)
886 flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
887 MAX310X_FLOWCTRL_SWFLOWEN_BIT;
888 max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
890 /* Get baud rate generator configuration */
891 baud = uart_get_baud_rate(port, termios, old,
892 port->uartclk / 16 / 0xffff,
895 /* Setup baudrate generator */
896 baud = max310x_set_baud(port, baud);
898 /* Update timeout according to new baud rate */
899 uart_update_timeout(port, termios->c_cflag, baud);
902 static int max310x_startup(struct uart_port *port)
904 unsigned int val, line = port->line;
905 struct max310x_port *s = dev_get_drvdata(port->dev);
907 s->devtype->power(port, 1);
909 /* Configure MODE1 register */
910 max310x_port_update(port, MAX310X_MODE1_REG,
911 MAX310X_MODE1_TRNSCVCTRL_BIT,
912 (s->pdata->uart_flags[line] & MAX310X_AUTO_DIR_CTRL)
913 ? MAX310X_MODE1_TRNSCVCTRL_BIT : 0);
915 /* Configure MODE2 register */
916 val = MAX310X_MODE2_RXEMPTINV_BIT;
917 if (s->pdata->uart_flags[line] & MAX310X_ECHO_SUPRESS)
918 val |= MAX310X_MODE2_ECHOSUPR_BIT;
921 val |= MAX310X_MODE2_FIFORST_BIT;
922 max310x_port_write(port, MAX310X_MODE2_REG, val);
923 max310x_port_update(port, MAX310X_MODE2_REG,
924 MAX310X_MODE2_FIFORST_BIT, 0);
926 /* Configure flow control levels */
927 /* Flow control halt level 96, resume level 48 */
928 max310x_port_write(port, MAX310X_FLOWLVL_REG,
929 MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
931 /* Clear IRQ status register */
932 max310x_port_read(port, MAX310X_IRQSTS_REG);
934 /* Enable RX, TX, CTS change interrupts */
935 val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
936 max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
941 static void max310x_shutdown(struct uart_port *port)
943 struct max310x_port *s = dev_get_drvdata(port->dev);
945 /* Disable all interrupts */
946 max310x_port_write(port, MAX310X_IRQEN_REG, 0);
948 s->devtype->power(port, 0);
951 static const char *max310x_type(struct uart_port *port)
953 struct max310x_port *s = dev_get_drvdata(port->dev);
955 return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
958 static int max310x_request_port(struct uart_port *port)
964 static void max310x_config_port(struct uart_port *port, int flags)
966 if (flags & UART_CONFIG_TYPE)
967 port->type = PORT_MAX310X;
970 static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
972 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
974 if (s->irq != port->irq)
980 static void max310x_null_void(struct uart_port *port)
985 static const struct uart_ops max310x_ops = {
986 .tx_empty = max310x_tx_empty,
987 .set_mctrl = max310x_set_mctrl,
988 .get_mctrl = max310x_get_mctrl,
989 .stop_tx = max310x_null_void,
990 .start_tx = max310x_start_tx,
991 .stop_rx = max310x_null_void,
992 .enable_ms = max310x_null_void,
993 .break_ctl = max310x_break_ctl,
994 .startup = max310x_startup,
995 .shutdown = max310x_shutdown,
996 .set_termios = max310x_set_termios,
997 .type = max310x_type,
998 .request_port = max310x_request_port,
999 .release_port = max310x_null_void,
1000 .config_port = max310x_config_port,
1001 .verify_port = max310x_verify_port,
1004 static int __maybe_unused max310x_suspend(struct device *dev)
1006 struct max310x_port *s = dev_get_drvdata(dev);
1009 for (i = 0; i < s->uart.nr; i++) {
1010 uart_suspend_port(&s->uart, &s->p[i].port);
1011 s->devtype->power(&s->p[i].port, 0);
1017 static int __maybe_unused max310x_resume(struct device *dev)
1019 struct max310x_port *s = dev_get_drvdata(dev);
1022 for (i = 0; i < s->uart.nr; i++) {
1023 s->devtype->power(&s->p[i].port, 1);
1024 uart_resume_port(&s->uart, &s->p[i].port);
1030 static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
1032 #ifdef CONFIG_GPIOLIB
1033 static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset)
1036 struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1037 struct uart_port *port = &s->p[offset / 4].port;
1039 val = max310x_port_read(port, MAX310X_GPIODATA_REG);
1041 return !!((val >> 4) & (1 << (offset % 4)));
1044 static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
1046 struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1047 struct uart_port *port = &s->p[offset / 4].port;
1049 max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1050 value ? 1 << (offset % 4) : 0);
1053 static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
1055 struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1056 struct uart_port *port = &s->p[offset / 4].port;
1058 max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
1063 static int max310x_gpio_direction_output(struct gpio_chip *chip,
1064 unsigned offset, int value)
1066 struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1067 struct uart_port *port = &s->p[offset / 4].port;
1069 max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1070 value ? 1 << (offset % 4) : 0);
1071 max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
1078 static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
1079 struct regmap *regmap, int irq)
1081 struct max310x_pdata *pdata = dev_get_platdata(dev);
1082 int i, ret, fmin, fmax, freq, uartclk;
1083 struct clk *clk_osc, *clk_xtal;
1084 struct max310x_port *s;
1088 return PTR_ERR(regmap);
1091 dev_err(dev, "No platform data supplied\n");
1095 /* Alloc port structure */
1096 s = devm_kzalloc(dev, sizeof(*s) +
1097 sizeof(struct max310x_one) * devtype->nr, GFP_KERNEL);
1099 dev_err(dev, "Error allocating port structure\n");
1103 clk_osc = devm_clk_get(dev, "osc");
1104 clk_xtal = devm_clk_get(dev, "xtal");
1105 if (!IS_ERR(clk_osc)) {
1109 } else if (!IS_ERR(clk_xtal)) {
1114 } else if (PTR_ERR(clk_osc) == -EPROBE_DEFER ||
1115 PTR_ERR(clk_xtal) == -EPROBE_DEFER) {
1116 return -EPROBE_DEFER;
1118 dev_err(dev, "Cannot get clock\n");
1122 ret = clk_prepare_enable(s->clk);
1126 freq = clk_get_rate(s->clk);
1127 /* Check frequency limits */
1128 if (freq < fmin || freq > fmax) {
1135 s->devtype = devtype;
1136 dev_set_drvdata(dev, s);
1138 mutex_init(&s->mutex);
1140 /* Check device to ensure we are talking to what we expect */
1141 ret = devtype->detect(dev);
1145 for (i = 0; i < devtype->nr; i++) {
1146 unsigned int offs = i << 5;
1149 regmap_write(s->regmap, MAX310X_MODE2_REG + offs,
1150 MAX310X_MODE2_RST_BIT);
1151 /* Clear port reset */
1152 regmap_write(s->regmap, MAX310X_MODE2_REG + offs, 0);
1154 /* Wait for port startup */
1156 regmap_read(s->regmap,
1157 MAX310X_BRGDIVLSB_REG + offs, &ret);
1158 } while (ret != 0x01);
1160 regmap_update_bits(s->regmap, MAX310X_MODE1_REG + offs,
1161 MAX310X_MODE1_AUTOSLEEP_BIT,
1162 MAX310X_MODE1_AUTOSLEEP_BIT);
1165 uartclk = max310x_set_ref_clk(s, freq, xtal);
1166 dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
1168 /* Register UART driver */
1169 s->uart.owner = THIS_MODULE;
1170 s->uart.dev_name = "ttyMAX";
1171 s->uart.major = MAX310X_MAJOR;
1172 s->uart.minor = MAX310X_MINOR;
1173 s->uart.nr = devtype->nr;
1174 ret = uart_register_driver(&s->uart);
1176 dev_err(dev, "Registering UART driver failed\n");
1180 for (i = 0; i < devtype->nr; i++) {
1181 /* Initialize port data */
1182 s->p[i].port.line = i;
1183 s->p[i].port.dev = dev;
1184 s->p[i].port.irq = irq;
1185 s->p[i].port.type = PORT_MAX310X;
1186 s->p[i].port.fifosize = MAX310X_FIFO_SIZE;
1187 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1188 s->p[i].port.iotype = UPIO_PORT;
1189 s->p[i].port.iobase = i * 0x20;
1190 s->p[i].port.membase = (void __iomem *)~0;
1191 s->p[i].port.uartclk = uartclk;
1192 s->p[i].port.ops = &max310x_ops;
1193 /* Disable all interrupts */
1194 max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
1195 /* Clear IRQ status register */
1196 max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
1197 /* Enable IRQ pin */
1198 max310x_port_update(&s->p[i].port, MAX310X_MODE1_REG,
1199 MAX310X_MODE1_IRQSEL_BIT,
1200 MAX310X_MODE1_IRQSEL_BIT);
1201 /* Initialize queue for start TX */
1202 INIT_WORK(&s->p[i].tx_work, max310x_wq_proc);
1203 /* Initialize queue for changing mode */
1204 INIT_WORK(&s->p[i].md_work, max310x_md_proc);
1206 uart_add_one_port(&s->uart, &s->p[i].port);
1207 /* Go to suspend mode */
1208 devtype->power(&s->p[i].port, 0);
1211 #ifdef CONFIG_GPIOLIB
1212 /* Setup GPIO cotroller */
1213 if (s->pdata->gpio_base) {
1214 s->gpio.owner = THIS_MODULE;
1216 s->gpio.label = dev_name(dev);
1217 s->gpio.direction_input = max310x_gpio_direction_input;
1218 s->gpio.get = max310x_gpio_get;
1219 s->gpio.direction_output= max310x_gpio_direction_output;
1220 s->gpio.set = max310x_gpio_set;
1221 s->gpio.base = s->pdata->gpio_base;
1222 s->gpio.ngpio = devtype->nr * 4;
1223 s->gpio.can_sleep = 1;
1224 if (!gpiochip_add(&s->gpio))
1227 dev_info(dev, "GPIO support not enabled\n");
1230 /* Setup interrupt */
1231 ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
1232 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1237 dev_err(dev, "Unable to reguest IRQ %i\n", irq);
1238 #ifdef CONFIG_GPIOLIB
1240 WARN_ON(gpiochip_remove(&s->gpio));
1244 clk_disable_unprepare(s->clk);
1249 static int max310x_remove(struct device *dev)
1251 struct max310x_port *s = dev_get_drvdata(dev);
1254 for (i = 0; i < s->uart.nr; i++) {
1255 cancel_work_sync(&s->p[i].tx_work);
1256 cancel_work_sync(&s->p[i].md_work);
1257 uart_remove_one_port(&s->uart, &s->p[i].port);
1258 s->devtype->power(&s->p[i].port, 0);
1261 uart_unregister_driver(&s->uart);
1262 clk_disable_unprepare(s->clk);
1264 #ifdef CONFIG_GPIOLIB
1266 ret = gpiochip_remove(&s->gpio);
1272 static struct regmap_config regcfg = {
1275 .write_flag_mask = 0x80,
1276 .cache_type = REGCACHE_RBTREE,
1277 .writeable_reg = max310x_reg_writeable,
1278 .volatile_reg = max310x_reg_volatile,
1279 .precious_reg = max310x_reg_precious,
1282 #ifdef CONFIG_SPI_MASTER
1283 static int max310x_spi_probe(struct spi_device *spi)
1285 struct max310x_devtype *devtype =
1286 (struct max310x_devtype *)spi_get_device_id(spi)->driver_data;
1287 struct regmap *regmap;
1291 spi->bits_per_word = 8;
1292 spi->mode = spi->mode ? : SPI_MODE_0;
1293 spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
1294 ret = spi_setup(spi);
1298 regcfg.max_register = devtype->nr * 0x20 - 1;
1299 regmap = devm_regmap_init_spi(spi, ®cfg);
1301 return max310x_probe(&spi->dev, devtype, regmap, spi->irq);
1304 static int max310x_spi_remove(struct spi_device *spi)
1306 return max310x_remove(&spi->dev);
1309 static const struct spi_device_id max310x_id_table[] = {
1310 { "max3107", (kernel_ulong_t)&max3107_devtype, },
1311 { "max3108", (kernel_ulong_t)&max3108_devtype, },
1312 { "max3109", (kernel_ulong_t)&max3109_devtype, },
1313 { "max14830", (kernel_ulong_t)&max14830_devtype, },
1316 MODULE_DEVICE_TABLE(spi, max310x_id_table);
1318 static struct spi_driver max310x_uart_driver = {
1320 .name = MAX310X_NAME,
1321 .owner = THIS_MODULE,
1322 .pm = &max310x_pm_ops,
1324 .probe = max310x_spi_probe,
1325 .remove = max310x_spi_remove,
1326 .id_table = max310x_id_table,
1328 module_spi_driver(max310x_uart_driver);
1331 MODULE_LICENSE("GPL");
1332 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1333 MODULE_DESCRIPTION("MAX310X serial driver");