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/i2c.h>
18 #include <linux/module.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/property.h>
21 #include <linux/regmap.h>
22 #include <linux/serial_core.h>
23 #include <linux/serial.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/spi/spi.h>
27 #include <linux/uaccess.h>
28
29 #define MAX310X_NAME "max310x"
30 #define MAX310X_MAJOR 204
31 #define MAX310X_MINOR 209
32 #define MAX310X_UART_NRMAX 16
33
34 /* MAX310X register definitions */
35 #define MAX310X_RHR_REG (0x00) /* RX FIFO */
36 #define MAX310X_THR_REG (0x00) /* TX FIFO */
37 #define MAX310X_IRQEN_REG (0x01) /* IRQ enable */
38 #define MAX310X_IRQSTS_REG (0x02) /* IRQ status */
39 #define MAX310X_LSR_IRQEN_REG (0x03) /* LSR IRQ enable */
40 #define MAX310X_LSR_IRQSTS_REG (0x04) /* LSR IRQ status */
41 #define MAX310X_REG_05 (0x05)
42 #define MAX310X_SPCHR_IRQEN_REG MAX310X_REG_05 /* Special char IRQ en */
43 #define MAX310X_SPCHR_IRQSTS_REG (0x06) /* Special char IRQ status */
44 #define MAX310X_STS_IRQEN_REG (0x07) /* Status IRQ enable */
45 #define MAX310X_STS_IRQSTS_REG (0x08) /* Status IRQ status */
46 #define MAX310X_MODE1_REG (0x09) /* MODE1 */
47 #define MAX310X_MODE2_REG (0x0a) /* MODE2 */
48 #define MAX310X_LCR_REG (0x0b) /* LCR */
49 #define MAX310X_RXTO_REG (0x0c) /* RX timeout */
50 #define MAX310X_HDPIXDELAY_REG (0x0d) /* Auto transceiver delays */
51 #define MAX310X_IRDA_REG (0x0e) /* IRDA settings */
52 #define MAX310X_FLOWLVL_REG (0x0f) /* Flow control levels */
53 #define MAX310X_FIFOTRIGLVL_REG (0x10) /* FIFO IRQ trigger levels */
54 #define MAX310X_TXFIFOLVL_REG (0x11) /* TX FIFO level */
55 #define MAX310X_RXFIFOLVL_REG (0x12) /* RX FIFO level */
56 #define MAX310X_FLOWCTRL_REG (0x13) /* Flow control */
57 #define MAX310X_XON1_REG (0x14) /* XON1 character */
58 #define MAX310X_XON2_REG (0x15) /* XON2 character */
59 #define MAX310X_XOFF1_REG (0x16) /* XOFF1 character */
60 #define MAX310X_XOFF2_REG (0x17) /* XOFF2 character */
61 #define MAX310X_GPIOCFG_REG (0x18) /* GPIO config */
62 #define MAX310X_GPIODATA_REG (0x19) /* GPIO data */
63 #define MAX310X_PLLCFG_REG (0x1a) /* PLL config */
64 #define MAX310X_BRGCFG_REG (0x1b) /* Baud rate generator conf */
65 #define MAX310X_BRGDIVLSB_REG (0x1c) /* Baud rate divisor LSB */
66 #define MAX310X_BRGDIVMSB_REG (0x1d) /* Baud rate divisor MSB */
67 #define MAX310X_CLKSRC_REG (0x1e) /* Clock source */
68 #define MAX310X_REG_1F (0x1f)
69
70 #define MAX310X_REVID_REG MAX310X_REG_1F /* Revision ID */
71
72 #define MAX310X_GLOBALIRQ_REG MAX310X_REG_1F /* Global IRQ (RO) */
73 #define MAX310X_GLOBALCMD_REG MAX310X_REG_1F /* Global Command (WO) */
74
75 /* Extended registers */
76 #define MAX310X_SPI_REVID_EXTREG MAX310X_REG_05 /* Revision ID */
77 #define MAX310X_I2C_REVID_EXTREG (0x25) /* Revision ID */
78
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 */
88
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 */
97
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 */
105
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 */
113
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 */
123
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 */
133
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
137 *
138 * Word length bits table:
139 * 00 -> 5 bit words
140 * 01 -> 6 bit words
141 * 10 -> 7 bit words
142 * 11 -> 8 bit words
143 */
144 #define MAX310X_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
145 *
146 * STOP length bit table:
147 * 0 -> 1 stop bit
148 * 1 -> 1-1.5 stop bits if
149 * word length is 5,
150 * 2 stop bits otherwise
151 */
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
158 /* IRDA register bits */
159 #define MAX310X_IRDA_IRDAEN_BIT (1 << 0) /* IRDA mode enable */
160 #define MAX310X_IRDA_SIR_BIT (1 << 1) /* SIR mode enable */
161
162 /* Flow control trigger level register masks */
163 #define MAX310X_FLOWLVL_HALT_MASK (0x000f) /* Flow control halt level */
164 #define MAX310X_FLOWLVL_RES_MASK (0x00f0) /* Flow control resume level */
165 #define MAX310X_FLOWLVL_HALT(words) ((words / 8) & 0x0f)
166 #define MAX310X_FLOWLVL_RES(words) (((words / 8) & 0x0f) << 4)
167
168 /* FIFO interrupt trigger level register masks */
169 #define MAX310X_FIFOTRIGLVL_TX_MASK (0x0f) /* TX FIFO trigger level */
170 #define MAX310X_FIFOTRIGLVL_RX_MASK (0xf0) /* RX FIFO trigger level */
171 #define MAX310X_FIFOTRIGLVL_TX(words) ((words / 8) & 0x0f)
172 #define MAX310X_FIFOTRIGLVL_RX(words) (((words / 8) & 0x0f) << 4)
173
174 /* Flow control register bits */
175 #define MAX310X_FLOWCTRL_AUTORTS_BIT (1 << 0) /* Auto RTS flow ctrl enable */
176 #define MAX310X_FLOWCTRL_AUTOCTS_BIT (1 << 1) /* Auto CTS flow ctrl enable */
177 #define MAX310X_FLOWCTRL_GPIADDR_BIT (1 << 2) /* Enables that GPIO inputs
178 * are used in conjunction with
179 * XOFF2 for definition of
180 * special character */
181 #define MAX310X_FLOWCTRL_SWFLOWEN_BIT (1 << 3) /* Auto SW flow ctrl enable */
182 #define MAX310X_FLOWCTRL_SWFLOW0_BIT (1 << 4) /* SWFLOW bit 0 */
183 #define MAX310X_FLOWCTRL_SWFLOW1_BIT (1 << 5) /* SWFLOW bit 1
184 *
185 * SWFLOW bits 1 & 0 table:
186 * 00 -> no transmitter flow
187 * control
188 * 01 -> receiver compares
189 * XON2 and XOFF2
190 * and controls
191 * transmitter
192 * 10 -> receiver compares
193 * XON1 and XOFF1
194 * and controls
195 * transmitter
196 * 11 -> receiver compares
197 * XON1, XON2, XOFF1 and
198 * XOFF2 and controls
199 * transmitter
200 */
201 #define MAX310X_FLOWCTRL_SWFLOW2_BIT (1 << 6) /* SWFLOW bit 2 */
202 #define MAX310X_FLOWCTRL_SWFLOW3_BIT (1 << 7) /* SWFLOW bit 3
203 *
204 * SWFLOW bits 3 & 2 table:
205 * 00 -> no received flow
206 * control
207 * 01 -> transmitter generates
208 * XON2 and XOFF2
209 * 10 -> transmitter generates
210 * XON1 and XOFF1
211 * 11 -> transmitter generates
212 * XON1, XON2, XOFF1 and
213 * XOFF2
214 */
215
216 /* PLL configuration register masks */
217 #define MAX310X_PLLCFG_PREDIV_MASK (0x3f) /* PLL predivision value */
218 #define MAX310X_PLLCFG_PLLFACTOR_MASK (0xc0) /* PLL multiplication factor */
219
220 /* Baud rate generator configuration register bits */
221 #define MAX310X_BRGCFG_2XMODE_BIT (1 << 4) /* Double baud rate */
222 #define MAX310X_BRGCFG_4XMODE_BIT (1 << 5) /* Quadruple baud rate */
223
224 /* Clock source register bits */
225 #define MAX310X_CLKSRC_CRYST_BIT (1 << 1) /* Crystal osc enable */
226 #define MAX310X_CLKSRC_PLL_BIT (1 << 2) /* PLL enable */
227 #define MAX310X_CLKSRC_PLLBYP_BIT (1 << 3) /* PLL bypass */
228 #define MAX310X_CLKSRC_EXTCLK_BIT (1 << 4) /* External clock enable */
229 #define MAX310X_CLKSRC_CLK2RTS_BIT (1 << 7) /* Baud clk to RTS pin */
230
231 /* Global commands */
232 #define MAX310X_EXTREG_ENBL (0xce)
233 #define MAX310X_EXTREG_DSBL (0xcd)
234
235 /* Misc definitions */
236 #define MAX310X_FIFO_SIZE (128)
237 #define MAX310x_REV_MASK (0xf8)
238 #define MAX310X_WRITE_BIT 0x80
239
240 /* Port startup definitions */
241 #define MAX310X_PORT_STARTUP_WAIT_RETRIES 20 /* Number of retries */
242 #define MAX310X_PORT_STARTUP_WAIT_DELAY_MS 10 /* Delay between retries */
243
244 /* Crystal-related definitions */
245 #define MAX310X_XTAL_WAIT_RETRIES 20 /* Number of retries */
246 #define MAX310X_XTAL_WAIT_DELAY_MS 10 /* Delay between retries */
247
248 /* MAX3107 specific */
249 #define MAX3107_REV_ID (0xa0)
250
251 /* MAX3109 specific */
252 #define MAX3109_REV_ID (0xc0)
253
254 /* MAX14830 specific */
255 #define MAX14830_BRGCFG_CLKDIS_BIT (1 << 6) /* Clock Disable */
256 #define MAX14830_REV_ID (0xb0)
257
258 struct max310x_if_cfg {
259 int (*extended_reg_enable)(struct device *dev, bool enable);
260
261 unsigned int rev_id_reg;
262 };
263
264 struct max310x_devtype {
265 struct {
266 unsigned short min;
267 unsigned short max;
268 } slave_addr;
269 char name[9];
270 int nr;
271 u8 mode1;
272 int (*detect)(struct device *);
273 void (*power)(struct uart_port *, int);
274 };
275
276 struct max310x_one {
277 struct uart_port port;
278 struct work_struct tx_work;
279 struct work_struct md_work;
280 struct work_struct rs_work;
281 struct regmap *regmap;
282
283 u8 rx_buf[MAX310X_FIFO_SIZE];
284 };
285 #define to_max310x_port(_port) \
286 container_of(_port, struct max310x_one, port)
287
288 struct max310x_port {
289 const struct max310x_devtype *devtype;
290 const struct max310x_if_cfg *if_cfg;
291 struct regmap *regmap;
292 struct clk *clk;
293 #ifdef CONFIG_GPIOLIB
294 struct gpio_chip gpio;
295 #endif
296 struct max310x_one p[];
297 };
298
299 static struct uart_driver max310x_uart = {
300 .owner = THIS_MODULE,
301 .driver_name = MAX310X_NAME,
302 .dev_name = "ttyMAX",
303 .major = MAX310X_MAJOR,
304 .minor = MAX310X_MINOR,
305 .nr = MAX310X_UART_NRMAX,
306 };
307
308 static DECLARE_BITMAP(max310x_lines, MAX310X_UART_NRMAX);
309
max310x_port_read(struct uart_port * port,u8 reg)310 static u8 max310x_port_read(struct uart_port *port, u8 reg)
311 {
312 struct max310x_one *one = to_max310x_port(port);
313 unsigned int val = 0;
314
315 regmap_read(one->regmap, reg, &val);
316
317 return val;
318 }
319
max310x_port_write(struct uart_port * port,u8 reg,u8 val)320 static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
321 {
322 struct max310x_one *one = to_max310x_port(port);
323
324 regmap_write(one->regmap, reg, val);
325 }
326
max310x_port_update(struct uart_port * port,u8 reg,u8 mask,u8 val)327 static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
328 {
329 struct max310x_one *one = to_max310x_port(port);
330
331 regmap_update_bits(one->regmap, reg, mask, val);
332 }
333
max3107_detect(struct device * dev)334 static int max3107_detect(struct device *dev)
335 {
336 struct max310x_port *s = dev_get_drvdata(dev);
337 unsigned int val = 0;
338 int ret;
339
340 ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val);
341 if (ret)
342 return ret;
343
344 if (((val & MAX310x_REV_MASK) != MAX3107_REV_ID)) {
345 dev_err(dev,
346 "%s ID 0x%02x does not match\n", s->devtype->name, val);
347 return -ENODEV;
348 }
349
350 return 0;
351 }
352
max3108_detect(struct device * dev)353 static int max3108_detect(struct device *dev)
354 {
355 struct max310x_port *s = dev_get_drvdata(dev);
356 unsigned int val = 0;
357 int ret;
358
359 /* MAX3108 have not REV ID register, we just check default value
360 * from clocksource register to make sure everything works.
361 */
362 ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val);
363 if (ret)
364 return ret;
365
366 if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) {
367 dev_err(dev, "%s not present\n", s->devtype->name);
368 return -ENODEV;
369 }
370
371 return 0;
372 }
373
max3109_detect(struct device * dev)374 static int max3109_detect(struct device *dev)
375 {
376 struct max310x_port *s = dev_get_drvdata(dev);
377 unsigned int val = 0;
378 int ret;
379
380 ret = s->if_cfg->extended_reg_enable(dev, true);
381 if (ret)
382 return ret;
383
384 regmap_read(s->regmap, s->if_cfg->rev_id_reg, &val);
385 s->if_cfg->extended_reg_enable(dev, false);
386 if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
387 dev_err(dev,
388 "%s ID 0x%02x does not match\n", s->devtype->name, val);
389 return -ENODEV;
390 }
391
392 return 0;
393 }
394
max310x_power(struct uart_port * port,int on)395 static void max310x_power(struct uart_port *port, int on)
396 {
397 max310x_port_update(port, MAX310X_MODE1_REG,
398 MAX310X_MODE1_FORCESLEEP_BIT,
399 on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT);
400 if (on)
401 msleep(50);
402 }
403
max14830_detect(struct device * dev)404 static int max14830_detect(struct device *dev)
405 {
406 struct max310x_port *s = dev_get_drvdata(dev);
407 unsigned int val = 0;
408 int ret;
409
410 ret = s->if_cfg->extended_reg_enable(dev, true);
411 if (ret)
412 return ret;
413
414 regmap_read(s->regmap, s->if_cfg->rev_id_reg, &val);
415 s->if_cfg->extended_reg_enable(dev, false);
416 if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
417 dev_err(dev,
418 "%s ID 0x%02x does not match\n", s->devtype->name, val);
419 return -ENODEV;
420 }
421
422 return 0;
423 }
424
max14830_power(struct uart_port * port,int on)425 static void max14830_power(struct uart_port *port, int on)
426 {
427 max310x_port_update(port, MAX310X_BRGCFG_REG,
428 MAX14830_BRGCFG_CLKDIS_BIT,
429 on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT);
430 if (on)
431 msleep(50);
432 }
433
434 static const struct max310x_devtype max3107_devtype = {
435 .name = "MAX3107",
436 .nr = 1,
437 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT | MAX310X_MODE1_IRQSEL_BIT,
438 .detect = max3107_detect,
439 .power = max310x_power,
440 .slave_addr = {
441 .min = 0x2c,
442 .max = 0x2f,
443 },
444 };
445
446 static const struct max310x_devtype max3108_devtype = {
447 .name = "MAX3108",
448 .nr = 1,
449 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT,
450 .detect = max3108_detect,
451 .power = max310x_power,
452 .slave_addr = {
453 .min = 0x60,
454 .max = 0x6f,
455 },
456 };
457
458 static const struct max310x_devtype max3109_devtype = {
459 .name = "MAX3109",
460 .nr = 2,
461 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT,
462 .detect = max3109_detect,
463 .power = max310x_power,
464 .slave_addr = {
465 .min = 0x60,
466 .max = 0x6f,
467 },
468 };
469
470 static const struct max310x_devtype max14830_devtype = {
471 .name = "MAX14830",
472 .nr = 4,
473 .mode1 = MAX310X_MODE1_IRQSEL_BIT,
474 .detect = max14830_detect,
475 .power = max14830_power,
476 .slave_addr = {
477 .min = 0x60,
478 .max = 0x6f,
479 },
480 };
481
max310x_reg_writeable(struct device * dev,unsigned int reg)482 static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
483 {
484 switch (reg) {
485 case MAX310X_IRQSTS_REG:
486 case MAX310X_LSR_IRQSTS_REG:
487 case MAX310X_SPCHR_IRQSTS_REG:
488 case MAX310X_STS_IRQSTS_REG:
489 case MAX310X_TXFIFOLVL_REG:
490 case MAX310X_RXFIFOLVL_REG:
491 return false;
492 default:
493 break;
494 }
495
496 return true;
497 }
498
max310x_reg_volatile(struct device * dev,unsigned int reg)499 static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
500 {
501 switch (reg) {
502 case MAX310X_RHR_REG:
503 case MAX310X_IRQSTS_REG:
504 case MAX310X_LSR_IRQSTS_REG:
505 case MAX310X_SPCHR_IRQSTS_REG:
506 case MAX310X_STS_IRQSTS_REG:
507 case MAX310X_TXFIFOLVL_REG:
508 case MAX310X_RXFIFOLVL_REG:
509 case MAX310X_GPIODATA_REG:
510 case MAX310X_BRGDIVLSB_REG:
511 case MAX310X_REG_05:
512 case MAX310X_REG_1F:
513 return true;
514 default:
515 break;
516 }
517
518 return false;
519 }
520
max310x_reg_precious(struct device * dev,unsigned int reg)521 static bool max310x_reg_precious(struct device *dev, unsigned int reg)
522 {
523 switch (reg) {
524 case MAX310X_RHR_REG:
525 case MAX310X_IRQSTS_REG:
526 case MAX310X_SPCHR_IRQSTS_REG:
527 case MAX310X_STS_IRQSTS_REG:
528 return true;
529 default:
530 break;
531 }
532
533 return false;
534 }
535
max310x_reg_noinc(struct device * dev,unsigned int reg)536 static bool max310x_reg_noinc(struct device *dev, unsigned int reg)
537 {
538 return reg == MAX310X_RHR_REG;
539 }
540
max310x_set_baud(struct uart_port * port,int baud)541 static int max310x_set_baud(struct uart_port *port, int baud)
542 {
543 unsigned int mode = 0, div = 0, frac = 0, c = 0, F = 0;
544
545 /*
546 * Calculate the integer divisor first. Select a proper mode
547 * in case if the requested baud is too high for the pre-defined
548 * clocks frequency.
549 */
550 div = port->uartclk / baud;
551 if (div < 8) {
552 /* Mode x4 */
553 c = 4;
554 mode = MAX310X_BRGCFG_4XMODE_BIT;
555 } else if (div < 16) {
556 /* Mode x2 */
557 c = 8;
558 mode = MAX310X_BRGCFG_2XMODE_BIT;
559 } else {
560 c = 16;
561 }
562
563 /* Calculate the divisor in accordance with the fraction coefficient */
564 div /= c;
565 F = c*baud;
566
567 /* Calculate the baud rate fraction */
568 if (div > 0)
569 frac = (16*(port->uartclk % F)) / F;
570 else
571 div = 1;
572
573 max310x_port_write(port, MAX310X_BRGDIVMSB_REG, div >> 8);
574 max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div);
575 max310x_port_write(port, MAX310X_BRGCFG_REG, frac | mode);
576
577 /* Return the actual baud rate we just programmed */
578 return (16*port->uartclk) / (c*(16*div + frac));
579 }
580
max310x_update_best_err(unsigned long f,long * besterr)581 static int max310x_update_best_err(unsigned long f, long *besterr)
582 {
583 /* Use baudrate 115200 for calculate error */
584 long err = f % (460800 * 16);
585
586 if ((*besterr < 0) || (*besterr > err)) {
587 *besterr = err;
588 return 0;
589 }
590
591 return 1;
592 }
593
max310x_set_ref_clk(struct device * dev,struct max310x_port * s,unsigned long freq,bool xtal)594 static s32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
595 unsigned long freq, bool xtal)
596 {
597 unsigned int div, clksrc, pllcfg = 0;
598 long besterr = -1;
599 unsigned long fdiv, fmul, bestfreq = freq;
600
601 /* First, update error without PLL */
602 max310x_update_best_err(freq, &besterr);
603
604 /* Try all possible PLL dividers */
605 for (div = 1; (div <= 63) && besterr; div++) {
606 fdiv = DIV_ROUND_CLOSEST(freq, div);
607
608 /* Try multiplier 6 */
609 fmul = fdiv * 6;
610 if ((fdiv >= 500000) && (fdiv <= 800000))
611 if (!max310x_update_best_err(fmul, &besterr)) {
612 pllcfg = (0 << 6) | div;
613 bestfreq = fmul;
614 }
615 /* Try multiplier 48 */
616 fmul = fdiv * 48;
617 if ((fdiv >= 850000) && (fdiv <= 1200000))
618 if (!max310x_update_best_err(fmul, &besterr)) {
619 pllcfg = (1 << 6) | div;
620 bestfreq = fmul;
621 }
622 /* Try multiplier 96 */
623 fmul = fdiv * 96;
624 if ((fdiv >= 425000) && (fdiv <= 1000000))
625 if (!max310x_update_best_err(fmul, &besterr)) {
626 pllcfg = (2 << 6) | div;
627 bestfreq = fmul;
628 }
629 /* Try multiplier 144 */
630 fmul = fdiv * 144;
631 if ((fdiv >= 390000) && (fdiv <= 667000))
632 if (!max310x_update_best_err(fmul, &besterr)) {
633 pllcfg = (3 << 6) | div;
634 bestfreq = fmul;
635 }
636 }
637
638 /* Configure clock source */
639 clksrc = MAX310X_CLKSRC_EXTCLK_BIT | (xtal ? MAX310X_CLKSRC_CRYST_BIT : 0);
640
641 /* Configure PLL */
642 if (pllcfg) {
643 clksrc |= MAX310X_CLKSRC_PLL_BIT;
644 regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
645 } else
646 clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
647
648 regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
649
650 /* Wait for crystal */
651 if (xtal) {
652 bool stable = false;
653 unsigned int try = 0, val = 0;
654
655 do {
656 msleep(MAX310X_XTAL_WAIT_DELAY_MS);
657 regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
658
659 if (val & MAX310X_STS_CLKREADY_BIT)
660 stable = true;
661 } while (!stable && (++try < MAX310X_XTAL_WAIT_RETRIES));
662
663 if (!stable)
664 return dev_err_probe(dev, -EAGAIN,
665 "clock is not stable\n");
666 }
667
668 return bestfreq;
669 }
670
max310x_batch_write(struct uart_port * port,u8 * txbuf,unsigned int len)671 static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
672 {
673 struct max310x_one *one = to_max310x_port(port);
674
675 regmap_noinc_write(one->regmap, MAX310X_THR_REG, txbuf, len);
676 }
677
max310x_batch_read(struct uart_port * port,u8 * rxbuf,unsigned int len)678 static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
679 {
680 struct max310x_one *one = to_max310x_port(port);
681
682 regmap_noinc_read(one->regmap, MAX310X_RHR_REG, rxbuf, len);
683 }
684
max310x_handle_rx(struct uart_port * port,unsigned int rxlen)685 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
686 {
687 struct max310x_one *one = to_max310x_port(port);
688 unsigned int sts, i;
689 u8 ch, flag;
690
691 if (port->read_status_mask == MAX310X_LSR_RXOVR_BIT) {
692 /* We are just reading, happily ignoring any error conditions.
693 * Break condition, parity checking, framing errors -- they
694 * are all ignored. That means that we can do a batch-read.
695 *
696 * There is a small opportunity for race if the RX FIFO
697 * overruns while we're reading the buffer; the datasheets says
698 * that the LSR register applies to the "current" character.
699 * That's also the reason why we cannot do batched reads when
700 * asked to check the individual statuses.
701 * */
702
703 sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
704 max310x_batch_read(port, one->rx_buf, rxlen);
705
706 port->icount.rx += rxlen;
707 flag = TTY_NORMAL;
708 sts &= port->read_status_mask;
709
710 if (sts & MAX310X_LSR_RXOVR_BIT) {
711 dev_warn_ratelimited(port->dev, "Hardware RX FIFO overrun\n");
712 port->icount.overrun++;
713 }
714
715 for (i = 0; i < (rxlen - 1); ++i)
716 uart_insert_char(port, sts, 0, one->rx_buf[i], flag);
717
718 /*
719 * Handle the overrun case for the last character only, since
720 * the RxFIFO overflow happens after it is pushed to the FIFO
721 * tail.
722 */
723 uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT,
724 one->rx_buf[rxlen-1], flag);
725
726 } else {
727 if (unlikely(rxlen >= port->fifosize)) {
728 dev_warn_ratelimited(port->dev, "Possible RX FIFO overrun\n");
729 port->icount.buf_overrun++;
730 /* Ensure sanity of RX level */
731 rxlen = port->fifosize;
732 }
733
734 while (rxlen--) {
735 ch = max310x_port_read(port, MAX310X_RHR_REG);
736 sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
737
738 sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT |
739 MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT;
740
741 port->icount.rx++;
742 flag = TTY_NORMAL;
743
744 if (unlikely(sts)) {
745 if (sts & MAX310X_LSR_RXBRK_BIT) {
746 port->icount.brk++;
747 if (uart_handle_break(port))
748 continue;
749 } else if (sts & MAX310X_LSR_RXPAR_BIT)
750 port->icount.parity++;
751 else if (sts & MAX310X_LSR_FRERR_BIT)
752 port->icount.frame++;
753 else if (sts & MAX310X_LSR_RXOVR_BIT)
754 port->icount.overrun++;
755
756 sts &= port->read_status_mask;
757 if (sts & MAX310X_LSR_RXBRK_BIT)
758 flag = TTY_BREAK;
759 else if (sts & MAX310X_LSR_RXPAR_BIT)
760 flag = TTY_PARITY;
761 else if (sts & MAX310X_LSR_FRERR_BIT)
762 flag = TTY_FRAME;
763 else if (sts & MAX310X_LSR_RXOVR_BIT)
764 flag = TTY_OVERRUN;
765 }
766
767 if (uart_handle_sysrq_char(port, ch))
768 continue;
769
770 if (sts & port->ignore_status_mask)
771 continue;
772
773 uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag);
774 }
775 }
776
777 tty_flip_buffer_push(&port->state->port);
778 }
779
max310x_handle_tx(struct uart_port * port)780 static void max310x_handle_tx(struct uart_port *port)
781 {
782 struct circ_buf *xmit = &port->state->xmit;
783 unsigned int txlen, to_send, until_end;
784
785 if (unlikely(port->x_char)) {
786 max310x_port_write(port, MAX310X_THR_REG, port->x_char);
787 port->icount.tx++;
788 port->x_char = 0;
789 return;
790 }
791
792 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
793 return;
794
795 /* Get length of data pending in circular buffer */
796 to_send = uart_circ_chars_pending(xmit);
797 until_end = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
798 if (likely(to_send)) {
799 /* Limit to size of TX FIFO */
800 txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
801 txlen = port->fifosize - txlen;
802 to_send = (to_send > txlen) ? txlen : to_send;
803
804 if (until_end < to_send) {
805 /* It's a circ buffer -- wrap around.
806 * We could do that in one SPI transaction, but meh. */
807 max310x_batch_write(port, xmit->buf + xmit->tail, until_end);
808 max310x_batch_write(port, xmit->buf, to_send - until_end);
809 } else {
810 max310x_batch_write(port, xmit->buf + xmit->tail, to_send);
811 }
812 uart_xmit_advance(port, to_send);
813 }
814
815 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
816 uart_write_wakeup(port);
817 }
818
max310x_start_tx(struct uart_port * port)819 static void max310x_start_tx(struct uart_port *port)
820 {
821 struct max310x_one *one = to_max310x_port(port);
822
823 schedule_work(&one->tx_work);
824 }
825
max310x_port_irq(struct max310x_port * s,int portno)826 static irqreturn_t max310x_port_irq(struct max310x_port *s, int portno)
827 {
828 struct uart_port *port = &s->p[portno].port;
829 irqreturn_t res = IRQ_NONE;
830
831 do {
832 unsigned int ists, lsr, rxlen;
833
834 /* Read IRQ status & RX FIFO level */
835 ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
836 rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
837 if (!ists && !rxlen)
838 break;
839
840 res = IRQ_HANDLED;
841
842 if (ists & MAX310X_IRQ_CTS_BIT) {
843 lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
844 uart_handle_cts_change(port, lsr & MAX310X_LSR_CTS_BIT);
845 }
846 if (rxlen)
847 max310x_handle_rx(port, rxlen);
848 if (ists & MAX310X_IRQ_TXEMPTY_BIT)
849 max310x_start_tx(port);
850 } while (1);
851 return res;
852 }
853
max310x_ist(int irq,void * dev_id)854 static irqreturn_t max310x_ist(int irq, void *dev_id)
855 {
856 struct max310x_port *s = (struct max310x_port *)dev_id;
857 bool handled = false;
858
859 if (s->devtype->nr > 1) {
860 do {
861 unsigned int val = ~0;
862
863 WARN_ON_ONCE(regmap_read(s->regmap,
864 MAX310X_GLOBALIRQ_REG, &val));
865 val = ((1 << s->devtype->nr) - 1) & ~val;
866 if (!val)
867 break;
868 if (max310x_port_irq(s, fls(val) - 1) == IRQ_HANDLED)
869 handled = true;
870 } while (1);
871 } else {
872 if (max310x_port_irq(s, 0) == IRQ_HANDLED)
873 handled = true;
874 }
875
876 return IRQ_RETVAL(handled);
877 }
878
max310x_tx_proc(struct work_struct * ws)879 static void max310x_tx_proc(struct work_struct *ws)
880 {
881 struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
882
883 max310x_handle_tx(&one->port);
884 }
885
max310x_tx_empty(struct uart_port * port)886 static unsigned int max310x_tx_empty(struct uart_port *port)
887 {
888 u8 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
889
890 return lvl ? 0 : TIOCSER_TEMT;
891 }
892
max310x_get_mctrl(struct uart_port * port)893 static unsigned int max310x_get_mctrl(struct uart_port *port)
894 {
895 /* DCD and DSR are not wired and CTS/RTS is handled automatically
896 * so just indicate DSR and CAR asserted
897 */
898 return TIOCM_DSR | TIOCM_CAR;
899 }
900
max310x_md_proc(struct work_struct * ws)901 static void max310x_md_proc(struct work_struct *ws)
902 {
903 struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
904
905 max310x_port_update(&one->port, MAX310X_MODE2_REG,
906 MAX310X_MODE2_LOOPBACK_BIT,
907 (one->port.mctrl & TIOCM_LOOP) ?
908 MAX310X_MODE2_LOOPBACK_BIT : 0);
909 }
910
max310x_set_mctrl(struct uart_port * port,unsigned int mctrl)911 static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
912 {
913 struct max310x_one *one = to_max310x_port(port);
914
915 schedule_work(&one->md_work);
916 }
917
max310x_break_ctl(struct uart_port * port,int break_state)918 static void max310x_break_ctl(struct uart_port *port, int break_state)
919 {
920 max310x_port_update(port, MAX310X_LCR_REG,
921 MAX310X_LCR_TXBREAK_BIT,
922 break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
923 }
924
max310x_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)925 static void max310x_set_termios(struct uart_port *port,
926 struct ktermios *termios,
927 const struct ktermios *old)
928 {
929 unsigned int lcr = 0, flow = 0;
930 int baud;
931
932 /* Mask termios capabilities we don't support */
933 termios->c_cflag &= ~CMSPAR;
934
935 /* Word size */
936 switch (termios->c_cflag & CSIZE) {
937 case CS5:
938 break;
939 case CS6:
940 lcr = MAX310X_LCR_LENGTH0_BIT;
941 break;
942 case CS7:
943 lcr = MAX310X_LCR_LENGTH1_BIT;
944 break;
945 case CS8:
946 default:
947 lcr = MAX310X_LCR_LENGTH1_BIT | MAX310X_LCR_LENGTH0_BIT;
948 break;
949 }
950
951 /* Parity */
952 if (termios->c_cflag & PARENB) {
953 lcr |= MAX310X_LCR_PARITY_BIT;
954 if (!(termios->c_cflag & PARODD))
955 lcr |= MAX310X_LCR_EVENPARITY_BIT;
956 }
957
958 /* Stop bits */
959 if (termios->c_cflag & CSTOPB)
960 lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
961
962 /* Update LCR register */
963 max310x_port_write(port, MAX310X_LCR_REG, lcr);
964
965 /* Set read status mask */
966 port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
967 if (termios->c_iflag & INPCK)
968 port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
969 MAX310X_LSR_FRERR_BIT;
970 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
971 port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
972
973 /* Set status ignore mask */
974 port->ignore_status_mask = 0;
975 if (termios->c_iflag & IGNBRK)
976 port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
977 if (!(termios->c_cflag & CREAD))
978 port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
979 MAX310X_LSR_RXOVR_BIT |
980 MAX310X_LSR_FRERR_BIT |
981 MAX310X_LSR_RXBRK_BIT;
982
983 /* Configure flow control */
984 max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
985 max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
986
987 /* Disable transmitter before enabling AutoCTS or auto transmitter
988 * flow control
989 */
990 if (termios->c_cflag & CRTSCTS || termios->c_iflag & IXOFF) {
991 max310x_port_update(port, MAX310X_MODE1_REG,
992 MAX310X_MODE1_TXDIS_BIT,
993 MAX310X_MODE1_TXDIS_BIT);
994 }
995
996 port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
997
998 if (termios->c_cflag & CRTSCTS) {
999 /* Enable AUTORTS and AUTOCTS */
1000 port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1001 flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
1002 MAX310X_FLOWCTRL_AUTORTS_BIT;
1003 }
1004 if (termios->c_iflag & IXON)
1005 flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
1006 MAX310X_FLOWCTRL_SWFLOWEN_BIT;
1007 if (termios->c_iflag & IXOFF) {
1008 port->status |= UPSTAT_AUTOXOFF;
1009 flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
1010 MAX310X_FLOWCTRL_SWFLOWEN_BIT;
1011 }
1012 max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
1013
1014 /* Enable transmitter after disabling AutoCTS and auto transmitter
1015 * flow control
1016 */
1017 if (!(termios->c_cflag & CRTSCTS) && !(termios->c_iflag & IXOFF)) {
1018 max310x_port_update(port, MAX310X_MODE1_REG,
1019 MAX310X_MODE1_TXDIS_BIT,
1020 0);
1021 }
1022
1023 /* Get baud rate generator configuration */
1024 baud = uart_get_baud_rate(port, termios, old,
1025 port->uartclk / 16 / 0xffff,
1026 port->uartclk / 4);
1027
1028 /* Setup baudrate generator */
1029 baud = max310x_set_baud(port, baud);
1030
1031 /* Update timeout according to new baud rate */
1032 uart_update_timeout(port, termios->c_cflag, baud);
1033 }
1034
max310x_rs_proc(struct work_struct * ws)1035 static void max310x_rs_proc(struct work_struct *ws)
1036 {
1037 struct max310x_one *one = container_of(ws, struct max310x_one, rs_work);
1038 unsigned int delay, mode1 = 0, mode2 = 0;
1039
1040 delay = (one->port.rs485.delay_rts_before_send << 4) |
1041 one->port.rs485.delay_rts_after_send;
1042 max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, delay);
1043
1044 if (one->port.rs485.flags & SER_RS485_ENABLED) {
1045 mode1 = MAX310X_MODE1_TRNSCVCTRL_BIT;
1046
1047 if (!(one->port.rs485.flags & SER_RS485_RX_DURING_TX))
1048 mode2 = MAX310X_MODE2_ECHOSUPR_BIT;
1049 }
1050
1051 max310x_port_update(&one->port, MAX310X_MODE1_REG,
1052 MAX310X_MODE1_TRNSCVCTRL_BIT, mode1);
1053 max310x_port_update(&one->port, MAX310X_MODE2_REG,
1054 MAX310X_MODE2_ECHOSUPR_BIT, mode2);
1055 }
1056
max310x_rs485_config(struct uart_port * port,struct ktermios * termios,struct serial_rs485 * rs485)1057 static int max310x_rs485_config(struct uart_port *port, struct ktermios *termios,
1058 struct serial_rs485 *rs485)
1059 {
1060 struct max310x_one *one = to_max310x_port(port);
1061
1062 if ((rs485->delay_rts_before_send > 0x0f) ||
1063 (rs485->delay_rts_after_send > 0x0f))
1064 return -ERANGE;
1065
1066 port->rs485 = *rs485;
1067
1068 schedule_work(&one->rs_work);
1069
1070 return 0;
1071 }
1072
max310x_startup(struct uart_port * port)1073 static int max310x_startup(struct uart_port *port)
1074 {
1075 struct max310x_port *s = dev_get_drvdata(port->dev);
1076 unsigned int val;
1077
1078 s->devtype->power(port, 1);
1079
1080 /* Configure MODE1 register */
1081 max310x_port_update(port, MAX310X_MODE1_REG,
1082 MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
1083
1084 /* Configure MODE2 register & Reset FIFOs*/
1085 val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
1086 max310x_port_write(port, MAX310X_MODE2_REG, val);
1087 max310x_port_update(port, MAX310X_MODE2_REG,
1088 MAX310X_MODE2_FIFORST_BIT, 0);
1089
1090 /* Configure mode1/mode2 to have rs485/rs232 enabled at startup */
1091 val = (clamp(port->rs485.delay_rts_before_send, 0U, 15U) << 4) |
1092 clamp(port->rs485.delay_rts_after_send, 0U, 15U);
1093 max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val);
1094
1095 if (port->rs485.flags & SER_RS485_ENABLED) {
1096 max310x_port_update(port, MAX310X_MODE1_REG,
1097 MAX310X_MODE1_TRNSCVCTRL_BIT,
1098 MAX310X_MODE1_TRNSCVCTRL_BIT);
1099
1100 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
1101 max310x_port_update(port, MAX310X_MODE2_REG,
1102 MAX310X_MODE2_ECHOSUPR_BIT,
1103 MAX310X_MODE2_ECHOSUPR_BIT);
1104 }
1105
1106 /* Configure flow control levels */
1107 /* Flow control halt level 96, resume level 48 */
1108 max310x_port_write(port, MAX310X_FLOWLVL_REG,
1109 MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
1110
1111 /* Clear IRQ status register */
1112 max310x_port_read(port, MAX310X_IRQSTS_REG);
1113
1114 /* Enable RX, TX, CTS change interrupts */
1115 val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
1116 max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
1117
1118 return 0;
1119 }
1120
max310x_shutdown(struct uart_port * port)1121 static void max310x_shutdown(struct uart_port *port)
1122 {
1123 struct max310x_port *s = dev_get_drvdata(port->dev);
1124
1125 /* Disable all interrupts */
1126 max310x_port_write(port, MAX310X_IRQEN_REG, 0);
1127
1128 s->devtype->power(port, 0);
1129 }
1130
max310x_type(struct uart_port * port)1131 static const char *max310x_type(struct uart_port *port)
1132 {
1133 struct max310x_port *s = dev_get_drvdata(port->dev);
1134
1135 return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
1136 }
1137
max310x_request_port(struct uart_port * port)1138 static int max310x_request_port(struct uart_port *port)
1139 {
1140 /* Do nothing */
1141 return 0;
1142 }
1143
max310x_config_port(struct uart_port * port,int flags)1144 static void max310x_config_port(struct uart_port *port, int flags)
1145 {
1146 if (flags & UART_CONFIG_TYPE)
1147 port->type = PORT_MAX310X;
1148 }
1149
max310x_verify_port(struct uart_port * port,struct serial_struct * s)1150 static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
1151 {
1152 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
1153 return -EINVAL;
1154 if (s->irq != port->irq)
1155 return -EINVAL;
1156
1157 return 0;
1158 }
1159
max310x_null_void(struct uart_port * port)1160 static void max310x_null_void(struct uart_port *port)
1161 {
1162 /* Do nothing */
1163 }
1164
1165 static const struct uart_ops max310x_ops = {
1166 .tx_empty = max310x_tx_empty,
1167 .set_mctrl = max310x_set_mctrl,
1168 .get_mctrl = max310x_get_mctrl,
1169 .stop_tx = max310x_null_void,
1170 .start_tx = max310x_start_tx,
1171 .stop_rx = max310x_null_void,
1172 .break_ctl = max310x_break_ctl,
1173 .startup = max310x_startup,
1174 .shutdown = max310x_shutdown,
1175 .set_termios = max310x_set_termios,
1176 .type = max310x_type,
1177 .request_port = max310x_request_port,
1178 .release_port = max310x_null_void,
1179 .config_port = max310x_config_port,
1180 .verify_port = max310x_verify_port,
1181 };
1182
max310x_suspend(struct device * dev)1183 static int __maybe_unused max310x_suspend(struct device *dev)
1184 {
1185 struct max310x_port *s = dev_get_drvdata(dev);
1186 int i;
1187
1188 for (i = 0; i < s->devtype->nr; i++) {
1189 uart_suspend_port(&max310x_uart, &s->p[i].port);
1190 s->devtype->power(&s->p[i].port, 0);
1191 }
1192
1193 return 0;
1194 }
1195
max310x_resume(struct device * dev)1196 static int __maybe_unused max310x_resume(struct device *dev)
1197 {
1198 struct max310x_port *s = dev_get_drvdata(dev);
1199 int i;
1200
1201 for (i = 0; i < s->devtype->nr; i++) {
1202 s->devtype->power(&s->p[i].port, 1);
1203 uart_resume_port(&max310x_uart, &s->p[i].port);
1204 }
1205
1206 return 0;
1207 }
1208
1209 static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
1210
1211 #ifdef CONFIG_GPIOLIB
max310x_gpio_get(struct gpio_chip * chip,unsigned offset)1212 static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset)
1213 {
1214 unsigned int val;
1215 struct max310x_port *s = gpiochip_get_data(chip);
1216 struct uart_port *port = &s->p[offset / 4].port;
1217
1218 val = max310x_port_read(port, MAX310X_GPIODATA_REG);
1219
1220 return !!((val >> 4) & (1 << (offset % 4)));
1221 }
1222
max310x_gpio_set(struct gpio_chip * chip,unsigned offset,int value)1223 static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
1224 {
1225 struct max310x_port *s = gpiochip_get_data(chip);
1226 struct uart_port *port = &s->p[offset / 4].port;
1227
1228 max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1229 value ? 1 << (offset % 4) : 0);
1230 }
1231
max310x_gpio_direction_input(struct gpio_chip * chip,unsigned offset)1232 static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
1233 {
1234 struct max310x_port *s = gpiochip_get_data(chip);
1235 struct uart_port *port = &s->p[offset / 4].port;
1236
1237 max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
1238
1239 return 0;
1240 }
1241
max310x_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)1242 static int max310x_gpio_direction_output(struct gpio_chip *chip,
1243 unsigned offset, int value)
1244 {
1245 struct max310x_port *s = gpiochip_get_data(chip);
1246 struct uart_port *port = &s->p[offset / 4].port;
1247
1248 max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1249 value ? 1 << (offset % 4) : 0);
1250 max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
1251 1 << (offset % 4));
1252
1253 return 0;
1254 }
1255
max310x_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)1256 static int max310x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
1257 unsigned long config)
1258 {
1259 struct max310x_port *s = gpiochip_get_data(chip);
1260 struct uart_port *port = &s->p[offset / 4].port;
1261
1262 switch (pinconf_to_config_param(config)) {
1263 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
1264 max310x_port_update(port, MAX310X_GPIOCFG_REG,
1265 1 << ((offset % 4) + 4),
1266 1 << ((offset % 4) + 4));
1267 return 0;
1268 case PIN_CONFIG_DRIVE_PUSH_PULL:
1269 max310x_port_update(port, MAX310X_GPIOCFG_REG,
1270 1 << ((offset % 4) + 4), 0);
1271 return 0;
1272 default:
1273 return -ENOTSUPP;
1274 }
1275 }
1276 #endif
1277
1278 static const struct serial_rs485 max310x_rs485_supported = {
1279 .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX,
1280 .delay_rts_before_send = 1,
1281 .delay_rts_after_send = 1,
1282 };
1283
max310x_probe(struct device * dev,const struct max310x_devtype * devtype,const struct max310x_if_cfg * if_cfg,struct regmap * regmaps[],int irq)1284 static int max310x_probe(struct device *dev, const struct max310x_devtype *devtype,
1285 const struct max310x_if_cfg *if_cfg,
1286 struct regmap *regmaps[], int irq)
1287 {
1288 int i, ret, fmin, fmax, freq;
1289 struct max310x_port *s;
1290 s32 uartclk = 0;
1291 bool xtal;
1292
1293 for (i = 0; i < devtype->nr; i++)
1294 if (IS_ERR(regmaps[i]))
1295 return PTR_ERR(regmaps[i]);
1296
1297 /* Alloc port structure */
1298 s = devm_kzalloc(dev, struct_size(s, p, devtype->nr), GFP_KERNEL);
1299 if (!s) {
1300 dev_err(dev, "Error allocating port structure\n");
1301 return -ENOMEM;
1302 }
1303
1304 /* Always ask for fixed clock rate from a property. */
1305 device_property_read_u32(dev, "clock-frequency", &uartclk);
1306
1307 xtal = device_property_match_string(dev, "clock-names", "osc") < 0;
1308 if (xtal)
1309 s->clk = devm_clk_get_optional(dev, "xtal");
1310 else
1311 s->clk = devm_clk_get_optional(dev, "osc");
1312 if (IS_ERR(s->clk))
1313 return PTR_ERR(s->clk);
1314
1315 ret = clk_prepare_enable(s->clk);
1316 if (ret)
1317 return ret;
1318
1319 freq = clk_get_rate(s->clk);
1320 if (freq == 0)
1321 freq = uartclk;
1322 if (freq == 0) {
1323 dev_err(dev, "Cannot get clock rate\n");
1324 ret = -EINVAL;
1325 goto out_clk;
1326 }
1327
1328 if (xtal) {
1329 fmin = 1000000;
1330 fmax = 4000000;
1331 } else {
1332 fmin = 500000;
1333 fmax = 35000000;
1334 }
1335
1336 /* Check frequency limits */
1337 if (freq < fmin || freq > fmax) {
1338 ret = -ERANGE;
1339 goto out_clk;
1340 }
1341
1342 s->regmap = regmaps[0];
1343 s->devtype = devtype;
1344 s->if_cfg = if_cfg;
1345 dev_set_drvdata(dev, s);
1346
1347 /* Check device to ensure we are talking to what we expect */
1348 ret = devtype->detect(dev);
1349 if (ret)
1350 goto out_clk;
1351
1352 for (i = 0; i < devtype->nr; i++) {
1353 bool started = false;
1354 unsigned int try = 0, val = 0;
1355
1356 /* Reset port */
1357 regmap_write(regmaps[i], MAX310X_MODE2_REG,
1358 MAX310X_MODE2_RST_BIT);
1359 /* Clear port reset */
1360 regmap_write(regmaps[i], MAX310X_MODE2_REG, 0);
1361
1362 /* Wait for port startup */
1363 do {
1364 msleep(MAX310X_PORT_STARTUP_WAIT_DELAY_MS);
1365 regmap_read(regmaps[i], MAX310X_BRGDIVLSB_REG, &val);
1366
1367 if (val == 0x01)
1368 started = true;
1369 } while (!started && (++try < MAX310X_PORT_STARTUP_WAIT_RETRIES));
1370
1371 if (!started) {
1372 ret = dev_err_probe(dev, -EAGAIN, "port reset failed\n");
1373 goto out_uart;
1374 }
1375
1376 regmap_write(regmaps[i], MAX310X_MODE1_REG, devtype->mode1);
1377 }
1378
1379 uartclk = max310x_set_ref_clk(dev, s, freq, xtal);
1380 if (uartclk < 0) {
1381 ret = uartclk;
1382 goto out_uart;
1383 }
1384
1385 dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
1386
1387 for (i = 0; i < devtype->nr; i++) {
1388 unsigned int line;
1389
1390 line = find_first_zero_bit(max310x_lines, MAX310X_UART_NRMAX);
1391 if (line == MAX310X_UART_NRMAX) {
1392 ret = -ERANGE;
1393 goto out_uart;
1394 }
1395
1396 /* Initialize port data */
1397 s->p[i].port.line = line;
1398 s->p[i].port.dev = dev;
1399 s->p[i].port.irq = irq;
1400 s->p[i].port.type = PORT_MAX310X;
1401 s->p[i].port.fifosize = MAX310X_FIFO_SIZE;
1402 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1403 s->p[i].port.iotype = UPIO_PORT;
1404 s->p[i].port.iobase = i;
1405 /*
1406 * Use all ones as membase to make sure uart_configure_port() in
1407 * serial_core.c does not abort for SPI/I2C devices where the
1408 * membase address is not applicable.
1409 */
1410 s->p[i].port.membase = (void __iomem *)~0;
1411 s->p[i].port.uartclk = uartclk;
1412 s->p[i].port.rs485_config = max310x_rs485_config;
1413 s->p[i].port.rs485_supported = max310x_rs485_supported;
1414 s->p[i].port.ops = &max310x_ops;
1415 s->p[i].regmap = regmaps[i];
1416
1417 /* Disable all interrupts */
1418 max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
1419 /* Clear IRQ status register */
1420 max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
1421 /* Initialize queue for start TX */
1422 INIT_WORK(&s->p[i].tx_work, max310x_tx_proc);
1423 /* Initialize queue for changing LOOPBACK mode */
1424 INIT_WORK(&s->p[i].md_work, max310x_md_proc);
1425 /* Initialize queue for changing RS485 mode */
1426 INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
1427
1428 /* Register port */
1429 ret = uart_add_one_port(&max310x_uart, &s->p[i].port);
1430 if (ret) {
1431 s->p[i].port.dev = NULL;
1432 goto out_uart;
1433 }
1434 set_bit(line, max310x_lines);
1435
1436 /* Go to suspend mode */
1437 devtype->power(&s->p[i].port, 0);
1438 }
1439
1440 #ifdef CONFIG_GPIOLIB
1441 /* Setup GPIO controller */
1442 s->gpio.owner = THIS_MODULE;
1443 s->gpio.parent = dev;
1444 s->gpio.label = devtype->name;
1445 s->gpio.direction_input = max310x_gpio_direction_input;
1446 s->gpio.get = max310x_gpio_get;
1447 s->gpio.direction_output= max310x_gpio_direction_output;
1448 s->gpio.set = max310x_gpio_set;
1449 s->gpio.set_config = max310x_gpio_set_config;
1450 s->gpio.base = -1;
1451 s->gpio.ngpio = devtype->nr * 4;
1452 s->gpio.can_sleep = 1;
1453 ret = devm_gpiochip_add_data(dev, &s->gpio, s);
1454 if (ret)
1455 goto out_uart;
1456 #endif
1457
1458 /* Setup interrupt */
1459 ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
1460 IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), s);
1461 if (!ret)
1462 return 0;
1463
1464 dev_err(dev, "Unable to request IRQ %i\n", irq);
1465
1466 out_uart:
1467 for (i = 0; i < devtype->nr; i++) {
1468 if (s->p[i].port.dev) {
1469 uart_remove_one_port(&max310x_uart, &s->p[i].port);
1470 clear_bit(s->p[i].port.line, max310x_lines);
1471 }
1472 }
1473
1474 out_clk:
1475 clk_disable_unprepare(s->clk);
1476
1477 return ret;
1478 }
1479
max310x_remove(struct device * dev)1480 static void max310x_remove(struct device *dev)
1481 {
1482 struct max310x_port *s = dev_get_drvdata(dev);
1483 int i;
1484
1485 for (i = 0; i < s->devtype->nr; i++) {
1486 cancel_work_sync(&s->p[i].tx_work);
1487 cancel_work_sync(&s->p[i].md_work);
1488 cancel_work_sync(&s->p[i].rs_work);
1489 uart_remove_one_port(&max310x_uart, &s->p[i].port);
1490 clear_bit(s->p[i].port.line, max310x_lines);
1491 s->devtype->power(&s->p[i].port, 0);
1492 }
1493
1494 clk_disable_unprepare(s->clk);
1495 }
1496
1497 static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
1498 { .compatible = "maxim,max3107", .data = &max3107_devtype, },
1499 { .compatible = "maxim,max3108", .data = &max3108_devtype, },
1500 { .compatible = "maxim,max3109", .data = &max3109_devtype, },
1501 { .compatible = "maxim,max14830", .data = &max14830_devtype },
1502 { }
1503 };
1504 MODULE_DEVICE_TABLE(of, max310x_dt_ids);
1505
1506 static struct regmap_config regcfg = {
1507 .reg_bits = 8,
1508 .val_bits = 8,
1509 .write_flag_mask = MAX310X_WRITE_BIT,
1510 .cache_type = REGCACHE_RBTREE,
1511 .max_register = MAX310X_REG_1F,
1512 .writeable_reg = max310x_reg_writeable,
1513 .volatile_reg = max310x_reg_volatile,
1514 .precious_reg = max310x_reg_precious,
1515 .writeable_noinc_reg = max310x_reg_noinc,
1516 .readable_noinc_reg = max310x_reg_noinc,
1517 .max_raw_read = MAX310X_FIFO_SIZE,
1518 .max_raw_write = MAX310X_FIFO_SIZE,
1519 };
1520
1521 #ifdef CONFIG_SPI_MASTER
max310x_spi_extended_reg_enable(struct device * dev,bool enable)1522 static int max310x_spi_extended_reg_enable(struct device *dev, bool enable)
1523 {
1524 struct max310x_port *s = dev_get_drvdata(dev);
1525
1526 return regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
1527 enable ? MAX310X_EXTREG_ENBL : MAX310X_EXTREG_DSBL);
1528 }
1529
1530 static const struct max310x_if_cfg __maybe_unused max310x_spi_if_cfg = {
1531 .extended_reg_enable = max310x_spi_extended_reg_enable,
1532 .rev_id_reg = MAX310X_SPI_REVID_EXTREG,
1533 };
1534
max310x_spi_probe(struct spi_device * spi)1535 static int max310x_spi_probe(struct spi_device *spi)
1536 {
1537 const struct max310x_devtype *devtype;
1538 struct regmap *regmaps[4];
1539 unsigned int i;
1540 int ret;
1541
1542 /* Setup SPI bus */
1543 spi->bits_per_word = 8;
1544 spi->mode = spi->mode ? : SPI_MODE_0;
1545 spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
1546 ret = spi_setup(spi);
1547 if (ret)
1548 return ret;
1549
1550 devtype = device_get_match_data(&spi->dev);
1551 if (!devtype)
1552 devtype = (struct max310x_devtype *)spi_get_device_id(spi)->driver_data;
1553
1554 for (i = 0; i < devtype->nr; i++) {
1555 u8 port_mask = i * 0x20;
1556 regcfg.read_flag_mask = port_mask;
1557 regcfg.write_flag_mask = port_mask | MAX310X_WRITE_BIT;
1558 regmaps[i] = devm_regmap_init_spi(spi, ®cfg);
1559 }
1560
1561 return max310x_probe(&spi->dev, devtype, &max310x_spi_if_cfg, regmaps, spi->irq);
1562 }
1563
max310x_spi_remove(struct spi_device * spi)1564 static void max310x_spi_remove(struct spi_device *spi)
1565 {
1566 max310x_remove(&spi->dev);
1567 }
1568
1569 static const struct spi_device_id max310x_id_table[] = {
1570 { "max3107", (kernel_ulong_t)&max3107_devtype, },
1571 { "max3108", (kernel_ulong_t)&max3108_devtype, },
1572 { "max3109", (kernel_ulong_t)&max3109_devtype, },
1573 { "max14830", (kernel_ulong_t)&max14830_devtype, },
1574 { }
1575 };
1576 MODULE_DEVICE_TABLE(spi, max310x_id_table);
1577
1578 static struct spi_driver max310x_spi_driver = {
1579 .driver = {
1580 .name = MAX310X_NAME,
1581 .of_match_table = max310x_dt_ids,
1582 .pm = &max310x_pm_ops,
1583 },
1584 .probe = max310x_spi_probe,
1585 .remove = max310x_spi_remove,
1586 .id_table = max310x_id_table,
1587 };
1588 #endif
1589
1590 #ifdef CONFIG_I2C
max310x_i2c_extended_reg_enable(struct device * dev,bool enable)1591 static int max310x_i2c_extended_reg_enable(struct device *dev, bool enable)
1592 {
1593 return 0;
1594 }
1595
1596 static struct regmap_config regcfg_i2c = {
1597 .reg_bits = 8,
1598 .val_bits = 8,
1599 .cache_type = REGCACHE_RBTREE,
1600 .writeable_reg = max310x_reg_writeable,
1601 .volatile_reg = max310x_reg_volatile,
1602 .precious_reg = max310x_reg_precious,
1603 .max_register = MAX310X_I2C_REVID_EXTREG,
1604 .writeable_noinc_reg = max310x_reg_noinc,
1605 .readable_noinc_reg = max310x_reg_noinc,
1606 .max_raw_read = MAX310X_FIFO_SIZE,
1607 .max_raw_write = MAX310X_FIFO_SIZE,
1608 };
1609
1610 static const struct max310x_if_cfg max310x_i2c_if_cfg = {
1611 .extended_reg_enable = max310x_i2c_extended_reg_enable,
1612 .rev_id_reg = MAX310X_I2C_REVID_EXTREG,
1613 };
1614
max310x_i2c_slave_addr(unsigned short addr,unsigned int nr)1615 static unsigned short max310x_i2c_slave_addr(unsigned short addr,
1616 unsigned int nr)
1617 {
1618 /*
1619 * For MAX14830 and MAX3109, the slave address depends on what the
1620 * A0 and A1 pins are tied to.
1621 * See Table I2C Address Map of the datasheet.
1622 * Based on that table, the following formulas were determined.
1623 * UART1 - UART0 = 0x10
1624 * UART2 - UART1 = 0x20 + 0x10
1625 * UART3 - UART2 = 0x10
1626 */
1627
1628 addr -= nr * 0x10;
1629
1630 if (nr >= 2)
1631 addr -= 0x20;
1632
1633 return addr;
1634 }
1635
max310x_i2c_probe(struct i2c_client * client)1636 static int max310x_i2c_probe(struct i2c_client *client)
1637 {
1638 const struct max310x_devtype *devtype;
1639 struct i2c_client *port_client;
1640 struct regmap *regmaps[4];
1641 unsigned int i;
1642 u8 port_addr;
1643
1644 devtype = device_get_match_data(&client->dev);
1645 if (!devtype)
1646 return dev_err_probe(&client->dev, -ENODEV, "Failed to match device\n");
1647
1648 if (client->addr < devtype->slave_addr.min ||
1649 client->addr > devtype->slave_addr.max)
1650 return dev_err_probe(&client->dev, -EINVAL,
1651 "Slave addr 0x%x outside of range [0x%x, 0x%x]\n",
1652 client->addr, devtype->slave_addr.min,
1653 devtype->slave_addr.max);
1654
1655 regmaps[0] = devm_regmap_init_i2c(client, ®cfg_i2c);
1656
1657 for (i = 1; i < devtype->nr; i++) {
1658 port_addr = max310x_i2c_slave_addr(client->addr, i);
1659 port_client = devm_i2c_new_dummy_device(&client->dev,
1660 client->adapter,
1661 port_addr);
1662
1663 regmaps[i] = devm_regmap_init_i2c(port_client, ®cfg_i2c);
1664 }
1665
1666 return max310x_probe(&client->dev, devtype, &max310x_i2c_if_cfg,
1667 regmaps, client->irq);
1668 }
1669
max310x_i2c_remove(struct i2c_client * client)1670 static void max310x_i2c_remove(struct i2c_client *client)
1671 {
1672 max310x_remove(&client->dev);
1673 }
1674
1675 static struct i2c_driver max310x_i2c_driver = {
1676 .driver = {
1677 .name = MAX310X_NAME,
1678 .of_match_table = max310x_dt_ids,
1679 .pm = &max310x_pm_ops,
1680 },
1681 .probe = max310x_i2c_probe,
1682 .remove = max310x_i2c_remove,
1683 };
1684 #endif
1685
max310x_uart_init(void)1686 static int __init max310x_uart_init(void)
1687 {
1688 int ret;
1689
1690 bitmap_zero(max310x_lines, MAX310X_UART_NRMAX);
1691
1692 ret = uart_register_driver(&max310x_uart);
1693 if (ret)
1694 return ret;
1695
1696 #ifdef CONFIG_SPI_MASTER
1697 ret = spi_register_driver(&max310x_spi_driver);
1698 if (ret)
1699 goto err_spi_register;
1700 #endif
1701
1702 #ifdef CONFIG_I2C
1703 ret = i2c_add_driver(&max310x_i2c_driver);
1704 if (ret)
1705 goto err_i2c_register;
1706 #endif
1707
1708 return 0;
1709
1710 #ifdef CONFIG_I2C
1711 err_i2c_register:
1712 spi_unregister_driver(&max310x_spi_driver);
1713 #endif
1714
1715 err_spi_register:
1716 uart_unregister_driver(&max310x_uart);
1717
1718 return ret;
1719 }
1720 module_init(max310x_uart_init);
1721
max310x_uart_exit(void)1722 static void __exit max310x_uart_exit(void)
1723 {
1724 #ifdef CONFIG_I2C
1725 i2c_del_driver(&max310x_i2c_driver);
1726 #endif
1727
1728 #ifdef CONFIG_SPI_MASTER
1729 spi_unregister_driver(&max310x_spi_driver);
1730 #endif
1731
1732 uart_unregister_driver(&max310x_uart);
1733 }
1734 module_exit(max310x_uart_exit);
1735
1736 MODULE_LICENSE("GPL");
1737 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1738 MODULE_DESCRIPTION("MAX310X serial driver");
1739