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 #define MAX310X_MAX_PORTS 4 /* Maximum number of UART ports per IC. */
34
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)
70 #define MAX310X_EXTREG_START (0x20) /* Only relevant in SPI mode. */
71
72 #define MAX310X_REVID_REG MAX310X_REG_1F /* Revision ID */
73
74 #define MAX310X_GLOBALIRQ_REG MAX310X_REG_1F /* Global IRQ (RO) */
75 #define MAX310X_GLOBALCMD_REG MAX310X_REG_1F /* Global Command (WO) */
76
77 /* Extended registers */
78 #define MAX310X_REVID_EXTREG (0x25) /* Revision ID
79 * (extended addressing space)
80 */
81 /* IRQ register bits */
82 #define MAX310X_IRQ_LSR_BIT (1 << 0) /* LSR interrupt */
83 #define MAX310X_IRQ_SPCHR_BIT (1 << 1) /* Special char interrupt */
84 #define MAX310X_IRQ_STS_BIT (1 << 2) /* Status interrupt */
85 #define MAX310X_IRQ_RXFIFO_BIT (1 << 3) /* RX FIFO interrupt */
86 #define MAX310X_IRQ_TXFIFO_BIT (1 << 4) /* TX FIFO interrupt */
87 #define MAX310X_IRQ_TXEMPTY_BIT (1 << 5) /* TX FIFO empty interrupt */
88 #define MAX310X_IRQ_RXEMPTY_BIT (1 << 6) /* RX FIFO empty interrupt */
89 #define MAX310X_IRQ_CTS_BIT (1 << 7) /* CTS interrupt */
90
91 /* LSR register bits */
92 #define MAX310X_LSR_RXTO_BIT (1 << 0) /* RX timeout */
93 #define MAX310X_LSR_RXOVR_BIT (1 << 1) /* RX overrun */
94 #define MAX310X_LSR_RXPAR_BIT (1 << 2) /* RX parity error */
95 #define MAX310X_LSR_FRERR_BIT (1 << 3) /* Frame error */
96 #define MAX310X_LSR_RXBRK_BIT (1 << 4) /* RX break */
97 #define MAX310X_LSR_RXNOISE_BIT (1 << 5) /* RX noise */
98 #define MAX310X_LSR_CTS_BIT (1 << 7) /* CTS pin state */
99
100 /* Special character register bits */
101 #define MAX310X_SPCHR_XON1_BIT (1 << 0) /* XON1 character */
102 #define MAX310X_SPCHR_XON2_BIT (1 << 1) /* XON2 character */
103 #define MAX310X_SPCHR_XOFF1_BIT (1 << 2) /* XOFF1 character */
104 #define MAX310X_SPCHR_XOFF2_BIT (1 << 3) /* XOFF2 character */
105 #define MAX310X_SPCHR_BREAK_BIT (1 << 4) /* RX break */
106 #define MAX310X_SPCHR_MULTIDROP_BIT (1 << 5) /* 9-bit multidrop addr char */
107
108 /* Status register bits */
109 #define MAX310X_STS_GPIO0_BIT (1 << 0) /* GPIO 0 interrupt */
110 #define MAX310X_STS_GPIO1_BIT (1 << 1) /* GPIO 1 interrupt */
111 #define MAX310X_STS_GPIO2_BIT (1 << 2) /* GPIO 2 interrupt */
112 #define MAX310X_STS_GPIO3_BIT (1 << 3) /* GPIO 3 interrupt */
113 #define MAX310X_STS_CLKREADY_BIT (1 << 5) /* Clock ready */
114 #define MAX310X_STS_SLEEP_BIT (1 << 6) /* Sleep interrupt */
115
116 /* MODE1 register bits */
117 #define MAX310X_MODE1_RXDIS_BIT (1 << 0) /* RX disable */
118 #define MAX310X_MODE1_TXDIS_BIT (1 << 1) /* TX disable */
119 #define MAX310X_MODE1_TXHIZ_BIT (1 << 2) /* TX pin three-state */
120 #define MAX310X_MODE1_RTSHIZ_BIT (1 << 3) /* RTS pin three-state */
121 #define MAX310X_MODE1_TRNSCVCTRL_BIT (1 << 4) /* Transceiver ctrl enable */
122 #define MAX310X_MODE1_FORCESLEEP_BIT (1 << 5) /* Force sleep mode */
123 #define MAX310X_MODE1_AUTOSLEEP_BIT (1 << 6) /* Auto sleep enable */
124 #define MAX310X_MODE1_IRQSEL_BIT (1 << 7) /* IRQ pin enable */
125
126 /* MODE2 register bits */
127 #define MAX310X_MODE2_RST_BIT (1 << 0) /* Chip reset */
128 #define MAX310X_MODE2_FIFORST_BIT (1 << 1) /* FIFO reset */
129 #define MAX310X_MODE2_RXTRIGINV_BIT (1 << 2) /* RX FIFO INT invert */
130 #define MAX310X_MODE2_RXEMPTINV_BIT (1 << 3) /* RX FIFO empty INT invert */
131 #define MAX310X_MODE2_SPCHR_BIT (1 << 4) /* Special chr detect enable */
132 #define MAX310X_MODE2_LOOPBACK_BIT (1 << 5) /* Internal loopback enable */
133 #define MAX310X_MODE2_MULTIDROP_BIT (1 << 6) /* 9-bit multidrop enable */
134 #define MAX310X_MODE2_ECHOSUPR_BIT (1 << 7) /* ECHO suppression enable */
135
136 /* LCR register bits */
137 #define MAX310X_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */
138 #define MAX310X_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1
139 *
140 * Word length bits table:
141 * 00 -> 5 bit words
142 * 01 -> 6 bit words
143 * 10 -> 7 bit words
144 * 11 -> 8 bit words
145 */
146 #define MAX310X_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
147 *
148 * STOP length bit table:
149 * 0 -> 1 stop bit
150 * 1 -> 1-1.5 stop bits if
151 * word length is 5,
152 * 2 stop bits otherwise
153 */
154 #define MAX310X_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */
155 #define MAX310X_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */
156 #define MAX310X_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */
157 #define MAX310X_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */
158 #define MAX310X_LCR_RTS_BIT (1 << 7) /* RTS pin control */
159
160 /* IRDA register bits */
161 #define MAX310X_IRDA_IRDAEN_BIT (1 << 0) /* IRDA mode enable */
162 #define MAX310X_IRDA_SIR_BIT (1 << 1) /* SIR mode enable */
163
164 /* Flow control trigger level register masks */
165 #define MAX310X_FLOWLVL_HALT_MASK GENMASK(3, 0) /* Flow control halt level */
166 #define MAX310X_FLOWLVL_RES_MASK GENMASK(7, 4) /* Flow control resume level */
167 #define MAX310X_FLOWLVL_HALT(words) ((words / 8) & 0x0f)
168 #define MAX310X_FLOWLVL_RES(words) (((words / 8) & 0x0f) << 4)
169
170 /* FIFO interrupt trigger level register masks */
171 #define MAX310X_FIFOTRIGLVL_TX_MASK GENMASK(3, 0) /* TX FIFO trigger level */
172 #define MAX310X_FIFOTRIGLVL_RX_MASK GENMASK(7, 4) /* RX FIFO trigger level */
173 #define MAX310X_FIFOTRIGLVL_TX(words) ((words / 8) & 0x0f)
174 #define MAX310X_FIFOTRIGLVL_RX(words) (((words / 8) & 0x0f) << 4)
175
176 /* Flow control register bits */
177 #define MAX310X_FLOWCTRL_AUTORTS_BIT (1 << 0) /* Auto RTS flow ctrl enable */
178 #define MAX310X_FLOWCTRL_AUTOCTS_BIT (1 << 1) /* Auto CTS flow ctrl enable */
179 #define MAX310X_FLOWCTRL_GPIADDR_BIT (1 << 2) /* Enables that GPIO inputs
180 * are used in conjunction with
181 * XOFF2 for definition of
182 * special character
183 */
184 #define MAX310X_FLOWCTRL_SWFLOWEN_BIT (1 << 3) /* Auto SW flow ctrl enable */
185 #define MAX310X_FLOWCTRL_SWFLOW0_BIT (1 << 4) /* SWFLOW bit 0 */
186 #define MAX310X_FLOWCTRL_SWFLOW1_BIT (1 << 5) /* SWFLOW bit 1
187 *
188 * SWFLOW bits 1 & 0 table:
189 * 00 -> no transmitter flow
190 * control
191 * 01 -> receiver compares
192 * XON2 and XOFF2
193 * and controls
194 * transmitter
195 * 10 -> receiver compares
196 * XON1 and XOFF1
197 * and controls
198 * transmitter
199 * 11 -> receiver compares
200 * XON1, XON2, XOFF1 and
201 * XOFF2 and controls
202 * transmitter
203 */
204 #define MAX310X_FLOWCTRL_SWFLOW2_BIT (1 << 6) /* SWFLOW bit 2 */
205 #define MAX310X_FLOWCTRL_SWFLOW3_BIT (1 << 7) /* SWFLOW bit 3
206 *
207 * SWFLOW bits 3 & 2 table:
208 * 00 -> no received flow
209 * control
210 * 01 -> transmitter generates
211 * XON2 and XOFF2
212 * 10 -> transmitter generates
213 * XON1 and XOFF1
214 * 11 -> transmitter generates
215 * XON1, XON2, XOFF1 and
216 * XOFF2
217 */
218
219 /* PLL configuration register masks */
220 #define MAX310X_PLLCFG_PREDIV_MASK GENMASK(5, 0) /* PLL predivision value */
221 #define MAX310X_PLLCFG_PLLFACTOR_MASK GENMASK(7, 6) /* PLL multiplication factor */
222
223 /* Baud rate generator configuration register bits */
224 #define MAX310X_BRGCFG_2XMODE_BIT (1 << 4) /* Double baud rate */
225 #define MAX310X_BRGCFG_4XMODE_BIT (1 << 5) /* Quadruple baud rate */
226
227 /* Clock source register bits */
228 #define MAX310X_CLKSRC_CRYST_BIT (1 << 1) /* Crystal osc enable */
229 #define MAX310X_CLKSRC_PLL_BIT (1 << 2) /* PLL enable */
230 #define MAX310X_CLKSRC_PLLBYP_BIT (1 << 3) /* PLL bypass */
231 #define MAX310X_CLKSRC_EXTCLK_BIT (1 << 4) /* External clock enable */
232 #define MAX310X_CLKSRC_CLK2RTS_BIT (1 << 7) /* Baud clk to RTS pin */
233
234 /* Global commands */
235 #define MAX310X_EXTREG_ENBL (0xce)
236 #define MAX310X_EXTREG_DSBL (0xcd)
237
238 /* Misc definitions */
239 #define MAX310X_FIFO_SIZE (128)
240 #define MAX310x_REV_MASK GENMASK(7, 3)
241 #define MAX310X_WRITE_BIT 0x80
242
243 /* Port startup definitions */
244 #define MAX310X_PORT_STARTUP_WAIT_RETRIES 20 /* Number of retries */
245 #define MAX310X_PORT_STARTUP_WAIT_DELAY_MS 10 /* Delay between retries */
246
247 /* Crystal-related definitions */
248 #define MAX310X_XTAL_WAIT_RETRIES 20 /* Number of retries */
249 #define MAX310X_XTAL_WAIT_DELAY_MS 10 /* Delay between retries */
250
251 /* MAX3107 specific */
252 #define MAX3107_REV_ID (0xa0)
253
254 /* MAX3109 specific */
255 #define MAX3109_REV_ID (0xc0)
256
257 /* MAX14830 specific */
258 #define MAX14830_BRGCFG_CLKDIS_BIT (1 << 6) /* Clock Disable */
259 #define MAX14830_REV_ID (0xb0)
260
261 struct max310x_if_cfg {
262 int (*extended_reg_enable)(struct device *dev, bool enable);
263 u8 rev_id_offset;
264 };
265
266 struct max310x_devtype {
267 struct {
268 unsigned short min;
269 unsigned short max;
270 } slave_addr; /* Relevant only in I2C mode. */
271 int nr;
272 char name[9];
273 u8 mode1;
274 u8 rev_id_val;
275 u8 rev_id_reg; /* Relevant only if rev_id_val is defined. */
276 u8 power_reg; /* Register address for power/sleep control. */
277 u8 power_bit; /* Bit for sleep or power-off mode (active high). */
278 };
279
280 struct max310x_one {
281 struct uart_port port;
282 struct work_struct tx_work;
283 struct work_struct md_work;
284 struct work_struct rs_work;
285 struct regmap *regmap;
286
287 u8 rx_buf[MAX310X_FIFO_SIZE];
288 };
289 #define to_max310x_port(_port) \
290 container_of(_port, struct max310x_one, port)
291
292 struct max310x_port {
293 const struct max310x_devtype *devtype;
294 const struct max310x_if_cfg *if_cfg;
295 struct regmap *regmap;
296 struct clk *clk;
297 #ifdef CONFIG_GPIOLIB
298 struct gpio_chip gpio;
299 #endif
300 struct max310x_one p[];
301 };
302
303 static struct uart_driver max310x_uart = {
304 .owner = THIS_MODULE,
305 .driver_name = MAX310X_NAME,
306 .dev_name = "ttyMAX",
307 .major = MAX310X_MAJOR,
308 .minor = MAX310X_MINOR,
309 .nr = MAX310X_UART_NRMAX,
310 };
311
312 static DECLARE_BITMAP(max310x_lines, MAX310X_UART_NRMAX);
313
max310x_port_read(struct uart_port * port,u8 reg)314 static u8 max310x_port_read(struct uart_port *port, u8 reg)
315 {
316 struct max310x_one *one = to_max310x_port(port);
317 unsigned int val = 0;
318
319 regmap_read(one->regmap, reg, &val);
320
321 return val;
322 }
323
max310x_port_write(struct uart_port * port,u8 reg,u8 val)324 static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
325 {
326 struct max310x_one *one = to_max310x_port(port);
327
328 regmap_write(one->regmap, reg, val);
329 }
330
max310x_port_update(struct uart_port * port,u8 reg,u8 mask,u8 val)331 static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
332 {
333 struct max310x_one *one = to_max310x_port(port);
334
335 regmap_update_bits(one->regmap, reg, mask, val);
336 }
337
max310x_detect(struct device * dev)338 static int max310x_detect(struct device *dev)
339 {
340 struct max310x_port *s = dev_get_drvdata(dev);
341 unsigned int val = 0;
342 int ret;
343
344 /* Check if variant supports REV ID register: */
345 if (s->devtype->rev_id_val) {
346 u8 rev_id_reg = s->devtype->rev_id_reg;
347
348 /* Check if REV ID is in extended addressing space: */
349 if (s->devtype->rev_id_reg >= MAX310X_EXTREG_START) {
350 ret = s->if_cfg->extended_reg_enable(dev, true);
351 if (ret)
352 return ret;
353
354 /* Adjust REV ID extended addressing space address: */
355 if (s->if_cfg->rev_id_offset)
356 rev_id_reg -= s->if_cfg->rev_id_offset;
357 }
358
359 regmap_read(s->regmap, rev_id_reg, &val);
360
361 if (s->devtype->rev_id_reg >= MAX310X_EXTREG_START) {
362 ret = s->if_cfg->extended_reg_enable(dev, false);
363 if (ret)
364 return ret;
365 }
366
367 if (((val & MAX310x_REV_MASK) != s->devtype->rev_id_val))
368 return dev_err_probe(dev, -ENODEV,
369 "%s ID 0x%02x does not match\n",
370 s->devtype->name, val);
371 } else {
372 /*
373 * For variant without REV ID register, just check default value
374 * from clocksource register to make sure everything works.
375 */
376 ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val);
377 if (ret)
378 return ret;
379
380 if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT))
381 return dev_err_probe(dev, -ENODEV,
382 "%s not present\n",
383 s->devtype->name);
384 }
385
386 return 0;
387 }
388
max310x_power(struct uart_port * port,int on)389 static void max310x_power(struct uart_port *port, int on)
390 {
391 struct max310x_port *s = dev_get_drvdata(port->dev);
392
393 max310x_port_update(port, s->devtype->power_reg, s->devtype->power_bit,
394 on ? 0 : s->devtype->power_bit);
395 if (on)
396 msleep(50);
397 }
398
399 static const struct max310x_devtype max3107_devtype = {
400 .name = "MAX3107",
401 .nr = 1,
402 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT | MAX310X_MODE1_IRQSEL_BIT,
403 .rev_id_val = MAX3107_REV_ID,
404 .rev_id_reg = MAX310X_REVID_REG,
405 .power_reg = MAX310X_MODE1_REG,
406 .power_bit = MAX310X_MODE1_FORCESLEEP_BIT,
407 .slave_addr = {
408 .min = 0x2c,
409 .max = 0x2f,
410 },
411 };
412
413 static const struct max310x_devtype max3108_devtype = {
414 .name = "MAX3108",
415 .nr = 1,
416 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT,
417 .rev_id_val = 0, /* Unsupported. */
418 .rev_id_reg = 0, /* Irrelevant when rev_id_val is not defined. */
419 .power_reg = MAX310X_MODE1_REG,
420 .power_bit = MAX310X_MODE1_FORCESLEEP_BIT,
421 .slave_addr = {
422 .min = 0x60,
423 .max = 0x6f,
424 },
425 };
426
427 static const struct max310x_devtype max3109_devtype = {
428 .name = "MAX3109",
429 .nr = 2,
430 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT,
431 .rev_id_val = MAX3109_REV_ID,
432 .rev_id_reg = MAX310X_REVID_EXTREG,
433 .power_reg = MAX310X_MODE1_REG,
434 .power_bit = MAX310X_MODE1_FORCESLEEP_BIT,
435 .slave_addr = {
436 .min = 0x60,
437 .max = 0x6f,
438 },
439 };
440
441 static const struct max310x_devtype max14830_devtype = {
442 .name = "MAX14830",
443 .nr = 4,
444 .mode1 = MAX310X_MODE1_IRQSEL_BIT,
445 .rev_id_val = MAX14830_REV_ID,
446 .rev_id_reg = MAX310X_REVID_EXTREG,
447 .power_reg = MAX310X_BRGCFG_REG,
448 .power_bit = MAX14830_BRGCFG_CLKDIS_BIT,
449 .slave_addr = {
450 .min = 0x60,
451 .max = 0x6f,
452 },
453 };
454
max310x_reg_writeable(struct device * dev,unsigned int reg)455 static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
456 {
457 switch (reg) {
458 case MAX310X_IRQSTS_REG:
459 case MAX310X_LSR_IRQSTS_REG:
460 case MAX310X_SPCHR_IRQSTS_REG:
461 case MAX310X_STS_IRQSTS_REG:
462 case MAX310X_TXFIFOLVL_REG:
463 case MAX310X_RXFIFOLVL_REG:
464 return false;
465 default:
466 return true;
467 }
468 }
469
max310x_reg_volatile(struct device * dev,unsigned int reg)470 static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
471 {
472 switch (reg) {
473 case MAX310X_RHR_REG:
474 case MAX310X_IRQSTS_REG:
475 case MAX310X_LSR_IRQSTS_REG:
476 case MAX310X_SPCHR_IRQSTS_REG:
477 case MAX310X_STS_IRQSTS_REG:
478 case MAX310X_TXFIFOLVL_REG:
479 case MAX310X_RXFIFOLVL_REG:
480 case MAX310X_GPIODATA_REG:
481 case MAX310X_BRGDIVLSB_REG:
482 case MAX310X_REG_05:
483 case MAX310X_REG_1F:
484 return true;
485 default:
486 return false;
487 }
488 }
489
max310x_reg_precious(struct device * dev,unsigned int reg)490 static bool max310x_reg_precious(struct device *dev, unsigned int reg)
491 {
492 switch (reg) {
493 case MAX310X_RHR_REG:
494 case MAX310X_IRQSTS_REG:
495 case MAX310X_SPCHR_IRQSTS_REG:
496 case MAX310X_STS_IRQSTS_REG:
497 return true;
498 default:
499 return false;
500 }
501 }
502
max310x_reg_noinc(struct device * dev,unsigned int reg)503 static bool max310x_reg_noinc(struct device *dev, unsigned int reg)
504 {
505 return reg == MAX310X_RHR_REG;
506 }
507
max310x_set_baud(struct uart_port * port,int baud)508 static int max310x_set_baud(struct uart_port *port, int baud)
509 {
510 unsigned int mode = 0, div = 0, frac = 0, c = 0, F = 0;
511
512 /*
513 * Calculate the integer divisor first. Select a proper mode
514 * in case if the requested baud is too high for the pre-defined
515 * clocks frequency.
516 */
517 div = port->uartclk / baud;
518 if (div < 8) {
519 /* Mode x4 */
520 c = 4;
521 mode = MAX310X_BRGCFG_4XMODE_BIT;
522 } else if (div < 16) {
523 /* Mode x2 */
524 c = 8;
525 mode = MAX310X_BRGCFG_2XMODE_BIT;
526 } else {
527 c = 16;
528 }
529
530 /* Calculate the divisor in accordance with the fraction coefficient */
531 div /= c;
532 F = c*baud;
533
534 /* Calculate the baud rate fraction */
535 if (div > 0)
536 frac = (16*(port->uartclk % F)) / F;
537 else
538 div = 1;
539
540 max310x_port_write(port, MAX310X_BRGDIVMSB_REG, div >> 8);
541 max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div);
542 max310x_port_write(port, MAX310X_BRGCFG_REG, frac | mode);
543
544 /* Return the actual baud rate we just programmed */
545 return (16*port->uartclk) / (c*(16*div + frac));
546 }
547
max310x_update_best_err(unsigned long f,long * besterr)548 static int max310x_update_best_err(unsigned long f, long *besterr)
549 {
550 /* Use baudrate 115200 for calculate error */
551 long err = f % (460800 * 16);
552
553 if ((*besterr < 0) || (*besterr > err)) {
554 *besterr = err;
555 return 0;
556 }
557
558 return 1;
559 }
560
max310x_set_ref_clk(struct device * dev,struct max310x_port * s,unsigned long freq,bool xtal)561 static s32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
562 unsigned long freq, bool xtal)
563 {
564 unsigned int div, clksrc, pllcfg = 0;
565 long besterr = -1;
566 unsigned long fdiv, fmul, bestfreq = freq;
567
568 /* First, update error without PLL */
569 max310x_update_best_err(freq, &besterr);
570
571 /* Try all possible PLL dividers */
572 for (div = 1; (div <= 63) && besterr; div++) {
573 fdiv = DIV_ROUND_CLOSEST(freq, div);
574
575 /* Try multiplier 6 */
576 fmul = fdiv * 6;
577 if ((fdiv >= 500000) && (fdiv <= 800000))
578 if (!max310x_update_best_err(fmul, &besterr)) {
579 pllcfg = (0 << 6) | div;
580 bestfreq = fmul;
581 }
582 /* Try multiplier 48 */
583 fmul = fdiv * 48;
584 if ((fdiv >= 850000) && (fdiv <= 1200000))
585 if (!max310x_update_best_err(fmul, &besterr)) {
586 pllcfg = (1 << 6) | div;
587 bestfreq = fmul;
588 }
589 /* Try multiplier 96 */
590 fmul = fdiv * 96;
591 if ((fdiv >= 425000) && (fdiv <= 1000000))
592 if (!max310x_update_best_err(fmul, &besterr)) {
593 pllcfg = (2 << 6) | div;
594 bestfreq = fmul;
595 }
596 /* Try multiplier 144 */
597 fmul = fdiv * 144;
598 if ((fdiv >= 390000) && (fdiv <= 667000))
599 if (!max310x_update_best_err(fmul, &besterr)) {
600 pllcfg = (3 << 6) | div;
601 bestfreq = fmul;
602 }
603 }
604
605 /* Configure clock source */
606 clksrc = MAX310X_CLKSRC_EXTCLK_BIT | (xtal ? MAX310X_CLKSRC_CRYST_BIT : 0);
607
608 /* Configure PLL */
609 if (pllcfg) {
610 clksrc |= MAX310X_CLKSRC_PLL_BIT;
611 regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
612 } else
613 clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
614
615 regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
616
617 /* Wait for crystal */
618 if (xtal) {
619 bool stable = false;
620 unsigned int try = 0, val = 0;
621
622 do {
623 msleep(MAX310X_XTAL_WAIT_DELAY_MS);
624 regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
625
626 if (val & MAX310X_STS_CLKREADY_BIT)
627 stable = true;
628 } while (!stable && (++try < MAX310X_XTAL_WAIT_RETRIES));
629
630 if (!stable)
631 return dev_err_probe(dev, -EAGAIN,
632 "clock is not stable\n");
633 }
634
635 return bestfreq;
636 }
637
max310x_batch_write(struct uart_port * port,u8 * txbuf,unsigned int len)638 static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
639 {
640 struct max310x_one *one = to_max310x_port(port);
641
642 regmap_noinc_write(one->regmap, MAX310X_THR_REG, txbuf, len);
643 }
644
max310x_batch_read(struct uart_port * port,u8 * rxbuf,unsigned int len)645 static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
646 {
647 struct max310x_one *one = to_max310x_port(port);
648
649 regmap_noinc_read(one->regmap, MAX310X_RHR_REG, rxbuf, len);
650 }
651
max310x_handle_rx(struct uart_port * port,unsigned int rxlen)652 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
653 {
654 struct max310x_one *one = to_max310x_port(port);
655 unsigned int sts, i;
656 u8 ch, flag;
657
658 if (port->read_status_mask == MAX310X_LSR_RXOVR_BIT) {
659 /*
660 * We are just reading, happily ignoring any error conditions.
661 * Break condition, parity checking, framing errors -- they
662 * are all ignored. That means that we can do a batch-read.
663 *
664 * There is a small opportunity for race if the RX FIFO
665 * overruns while we're reading the buffer; the datasheets says
666 * that the LSR register applies to the "current" character.
667 * That's also the reason why we cannot do batched reads when
668 * asked to check the individual statuses.
669 */
670
671 sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
672 max310x_batch_read(port, one->rx_buf, rxlen);
673
674 port->icount.rx += rxlen;
675 flag = TTY_NORMAL;
676 sts &= port->read_status_mask;
677
678 if (sts & MAX310X_LSR_RXOVR_BIT) {
679 dev_warn_ratelimited(port->dev, "Hardware RX FIFO overrun\n");
680 port->icount.overrun++;
681 }
682
683 for (i = 0; i < (rxlen - 1); ++i)
684 uart_insert_char(port, sts, 0, one->rx_buf[i], flag);
685
686 /*
687 * Handle the overrun case for the last character only, since
688 * the RxFIFO overflow happens after it is pushed to the FIFO
689 * tail.
690 */
691 uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT,
692 one->rx_buf[rxlen-1], flag);
693
694 } else {
695 if (unlikely(rxlen >= port->fifosize)) {
696 dev_warn_ratelimited(port->dev, "Possible RX FIFO overrun\n");
697 port->icount.buf_overrun++;
698 /* Ensure sanity of RX level */
699 rxlen = port->fifosize;
700 }
701
702 while (rxlen--) {
703 ch = max310x_port_read(port, MAX310X_RHR_REG);
704 sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
705
706 sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT |
707 MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT;
708
709 port->icount.rx++;
710 flag = TTY_NORMAL;
711
712 if (unlikely(sts)) {
713 if (sts & MAX310X_LSR_RXBRK_BIT) {
714 port->icount.brk++;
715 if (uart_handle_break(port))
716 continue;
717 } else if (sts & MAX310X_LSR_RXPAR_BIT)
718 port->icount.parity++;
719 else if (sts & MAX310X_LSR_FRERR_BIT)
720 port->icount.frame++;
721 else if (sts & MAX310X_LSR_RXOVR_BIT)
722 port->icount.overrun++;
723
724 sts &= port->read_status_mask;
725 if (sts & MAX310X_LSR_RXBRK_BIT)
726 flag = TTY_BREAK;
727 else if (sts & MAX310X_LSR_RXPAR_BIT)
728 flag = TTY_PARITY;
729 else if (sts & MAX310X_LSR_FRERR_BIT)
730 flag = TTY_FRAME;
731 else if (sts & MAX310X_LSR_RXOVR_BIT)
732 flag = TTY_OVERRUN;
733 }
734
735 if (uart_handle_sysrq_char(port, ch))
736 continue;
737
738 if (sts & port->ignore_status_mask)
739 continue;
740
741 uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag);
742 }
743 }
744
745 tty_flip_buffer_push(&port->state->port);
746 }
747
max310x_handle_tx(struct uart_port * port)748 static void max310x_handle_tx(struct uart_port *port)
749 {
750 struct tty_port *tport = &port->state->port;
751 unsigned int txlen, to_send;
752 unsigned char *tail;
753
754 if (unlikely(port->x_char)) {
755 max310x_port_write(port, MAX310X_THR_REG, port->x_char);
756 port->icount.tx++;
757 port->x_char = 0;
758 return;
759 }
760
761 if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port))
762 return;
763
764 /*
765 * It's a circ buffer -- wrap around.
766 * We could do that in one SPI transaction, but meh.
767 */
768 while (!kfifo_is_empty(&tport->xmit_fifo)) {
769 /* Limit to space available in TX FIFO */
770 txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
771 txlen = port->fifosize - txlen;
772 if (!txlen)
773 break;
774
775 to_send = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail, txlen);
776 max310x_batch_write(port, tail, to_send);
777 uart_xmit_advance(port, to_send);
778 }
779
780 if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
781 uart_write_wakeup(port);
782 }
783
max310x_start_tx(struct uart_port * port)784 static void max310x_start_tx(struct uart_port *port)
785 {
786 struct max310x_one *one = to_max310x_port(port);
787
788 schedule_work(&one->tx_work);
789 }
790
max310x_port_irq(struct max310x_port * s,int portno)791 static irqreturn_t max310x_port_irq(struct max310x_port *s, int portno)
792 {
793 struct uart_port *port = &s->p[portno].port;
794 irqreturn_t res = IRQ_NONE;
795
796 do {
797 unsigned int ists, lsr, rxlen;
798
799 /* Read IRQ status & RX FIFO level */
800 ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
801 rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
802 if (!ists && !rxlen)
803 break;
804
805 res = IRQ_HANDLED;
806
807 if (ists & MAX310X_IRQ_CTS_BIT) {
808 lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
809 uart_handle_cts_change(port, lsr & MAX310X_LSR_CTS_BIT);
810 }
811 if (rxlen)
812 max310x_handle_rx(port, rxlen);
813 if (ists & MAX310X_IRQ_TXEMPTY_BIT)
814 max310x_start_tx(port);
815 } while (1);
816
817 return res;
818 }
819
max310x_ist(int irq,void * dev_id)820 static irqreturn_t max310x_ist(int irq, void *dev_id)
821 {
822 struct max310x_port *s = (struct max310x_port *)dev_id;
823 bool handled = false;
824
825 if (s->devtype->nr > 1) {
826 do {
827 unsigned int val = ~0;
828
829 WARN_ON_ONCE(regmap_read(s->regmap,
830 MAX310X_GLOBALIRQ_REG, &val));
831 val = ((1 << s->devtype->nr) - 1) & ~val;
832 if (!val)
833 break;
834 if (max310x_port_irq(s, fls(val) - 1) == IRQ_HANDLED)
835 handled = true;
836 } while (1);
837 } else {
838 if (max310x_port_irq(s, 0) == IRQ_HANDLED)
839 handled = true;
840 }
841
842 return IRQ_RETVAL(handled);
843 }
844
max310x_tx_proc(struct work_struct * ws)845 static void max310x_tx_proc(struct work_struct *ws)
846 {
847 struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
848
849 max310x_handle_tx(&one->port);
850 }
851
max310x_tx_empty(struct uart_port * port)852 static unsigned int max310x_tx_empty(struct uart_port *port)
853 {
854 u8 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
855
856 return lvl ? 0 : TIOCSER_TEMT;
857 }
858
max310x_get_mctrl(struct uart_port * port)859 static unsigned int max310x_get_mctrl(struct uart_port *port)
860 {
861 /*
862 * DCD and DSR are not wired and CTS/RTS is handled automatically
863 * so just indicate DSR and CAR asserted
864 */
865 return TIOCM_DSR | TIOCM_CAR;
866 }
867
max310x_md_proc(struct work_struct * ws)868 static void max310x_md_proc(struct work_struct *ws)
869 {
870 struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
871
872 max310x_port_update(&one->port, MAX310X_MODE2_REG,
873 MAX310X_MODE2_LOOPBACK_BIT,
874 (one->port.mctrl & TIOCM_LOOP) ?
875 MAX310X_MODE2_LOOPBACK_BIT : 0);
876 }
877
max310x_set_mctrl(struct uart_port * port,unsigned int mctrl)878 static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
879 {
880 struct max310x_one *one = to_max310x_port(port);
881
882 schedule_work(&one->md_work);
883 }
884
max310x_break_ctl(struct uart_port * port,int break_state)885 static void max310x_break_ctl(struct uart_port *port, int break_state)
886 {
887 max310x_port_update(port, MAX310X_LCR_REG,
888 MAX310X_LCR_TXBREAK_BIT,
889 break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
890 }
891
max310x_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)892 static void max310x_set_termios(struct uart_port *port,
893 struct ktermios *termios,
894 const struct ktermios *old)
895 {
896 unsigned int lcr = 0, flow = 0;
897 int baud;
898
899 /* Mask termios capabilities we don't support */
900 termios->c_cflag &= ~CMSPAR;
901
902 /* Word size */
903 switch (termios->c_cflag & CSIZE) {
904 case CS5:
905 break;
906 case CS6:
907 lcr = MAX310X_LCR_LENGTH0_BIT;
908 break;
909 case CS7:
910 lcr = MAX310X_LCR_LENGTH1_BIT;
911 break;
912 case CS8:
913 default:
914 lcr = MAX310X_LCR_LENGTH1_BIT | MAX310X_LCR_LENGTH0_BIT;
915 break;
916 }
917
918 /* Parity */
919 if (termios->c_cflag & PARENB) {
920 lcr |= MAX310X_LCR_PARITY_BIT;
921 if (!(termios->c_cflag & PARODD))
922 lcr |= MAX310X_LCR_EVENPARITY_BIT;
923 }
924
925 /* Stop bits */
926 if (termios->c_cflag & CSTOPB)
927 lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
928
929 /* Update LCR register */
930 max310x_port_write(port, MAX310X_LCR_REG, lcr);
931
932 /* Set read status mask */
933 port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
934 if (termios->c_iflag & INPCK)
935 port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
936 MAX310X_LSR_FRERR_BIT;
937 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
938 port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
939
940 /* Set status ignore mask */
941 port->ignore_status_mask = 0;
942 if (termios->c_iflag & IGNBRK)
943 port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
944 if (!(termios->c_cflag & CREAD))
945 port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
946 MAX310X_LSR_RXOVR_BIT |
947 MAX310X_LSR_FRERR_BIT |
948 MAX310X_LSR_RXBRK_BIT;
949
950 /* Configure flow control */
951 max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
952 max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
953
954 /*
955 * Disable transmitter before enabling AutoCTS or auto transmitter
956 * flow control
957 */
958 if (termios->c_cflag & CRTSCTS || termios->c_iflag & IXOFF) {
959 max310x_port_update(port, MAX310X_MODE1_REG,
960 MAX310X_MODE1_TXDIS_BIT,
961 MAX310X_MODE1_TXDIS_BIT);
962 }
963
964 port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
965
966 if (termios->c_cflag & CRTSCTS) {
967 /* Enable AUTORTS and AUTOCTS */
968 port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
969 flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
970 MAX310X_FLOWCTRL_AUTORTS_BIT;
971 }
972 if (termios->c_iflag & IXON)
973 flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
974 MAX310X_FLOWCTRL_SWFLOWEN_BIT;
975 if (termios->c_iflag & IXOFF) {
976 port->status |= UPSTAT_AUTOXOFF;
977 flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
978 MAX310X_FLOWCTRL_SWFLOWEN_BIT;
979 }
980 max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
981
982 /*
983 * Enable transmitter after disabling AutoCTS and auto transmitter
984 * flow control
985 */
986 if (!(termios->c_cflag & CRTSCTS) && !(termios->c_iflag & IXOFF)) {
987 max310x_port_update(port, MAX310X_MODE1_REG,
988 MAX310X_MODE1_TXDIS_BIT,
989 0);
990 }
991
992 /* Get baud rate generator configuration */
993 baud = uart_get_baud_rate(port, termios, old,
994 port->uartclk / 16 / 0xffff,
995 port->uartclk / 4);
996
997 /* Setup baudrate generator */
998 baud = max310x_set_baud(port, baud);
999
1000 /* Update timeout according to new baud rate */
1001 uart_update_timeout(port, termios->c_cflag, baud);
1002 }
1003
max310x_rs_proc(struct work_struct * ws)1004 static void max310x_rs_proc(struct work_struct *ws)
1005 {
1006 struct max310x_one *one = container_of(ws, struct max310x_one, rs_work);
1007 unsigned int delay, mode1 = 0, mode2 = 0;
1008
1009 delay = (one->port.rs485.delay_rts_before_send << 4) |
1010 one->port.rs485.delay_rts_after_send;
1011 max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, delay);
1012
1013 if (one->port.rs485.flags & SER_RS485_ENABLED) {
1014 mode1 = MAX310X_MODE1_TRNSCVCTRL_BIT;
1015
1016 if (!(one->port.rs485.flags & SER_RS485_RX_DURING_TX))
1017 mode2 = MAX310X_MODE2_ECHOSUPR_BIT;
1018 }
1019
1020 max310x_port_update(&one->port, MAX310X_MODE1_REG,
1021 MAX310X_MODE1_TRNSCVCTRL_BIT, mode1);
1022 max310x_port_update(&one->port, MAX310X_MODE2_REG,
1023 MAX310X_MODE2_ECHOSUPR_BIT, mode2);
1024 }
1025
max310x_rs485_config(struct uart_port * port,struct ktermios * termios,struct serial_rs485 * rs485)1026 static int max310x_rs485_config(struct uart_port *port, struct ktermios *termios,
1027 struct serial_rs485 *rs485)
1028 {
1029 struct max310x_one *one = to_max310x_port(port);
1030
1031 if ((rs485->delay_rts_before_send > 0x0f) ||
1032 (rs485->delay_rts_after_send > 0x0f))
1033 return -ERANGE;
1034
1035 port->rs485 = *rs485;
1036
1037 schedule_work(&one->rs_work);
1038
1039 return 0;
1040 }
1041
max310x_startup(struct uart_port * port)1042 static int max310x_startup(struct uart_port *port)
1043 {
1044 unsigned int val;
1045
1046 max310x_power(port, 1);
1047
1048 /* Configure MODE1 register */
1049 max310x_port_update(port, MAX310X_MODE1_REG,
1050 MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
1051
1052 /* Configure MODE2 register & Reset FIFOs*/
1053 val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
1054 max310x_port_write(port, MAX310X_MODE2_REG, val);
1055 max310x_port_update(port, MAX310X_MODE2_REG,
1056 MAX310X_MODE2_FIFORST_BIT, 0);
1057
1058 /* Configure mode1/mode2 to have rs485/rs232 enabled at startup */
1059 val = (clamp(port->rs485.delay_rts_before_send, 0U, 15U) << 4) |
1060 clamp(port->rs485.delay_rts_after_send, 0U, 15U);
1061 max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val);
1062
1063 if (port->rs485.flags & SER_RS485_ENABLED) {
1064 max310x_port_update(port, MAX310X_MODE1_REG,
1065 MAX310X_MODE1_TRNSCVCTRL_BIT,
1066 MAX310X_MODE1_TRNSCVCTRL_BIT);
1067
1068 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
1069 max310x_port_update(port, MAX310X_MODE2_REG,
1070 MAX310X_MODE2_ECHOSUPR_BIT,
1071 MAX310X_MODE2_ECHOSUPR_BIT);
1072 }
1073
1074 /*
1075 * Configure flow control levels:
1076 * resume: 48
1077 * halt: 96
1078 */
1079 max310x_port_write(port, MAX310X_FLOWLVL_REG,
1080 MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
1081
1082 /* Clear IRQ status register */
1083 max310x_port_read(port, MAX310X_IRQSTS_REG);
1084
1085 /* Enable RX, TX, CTS change interrupts */
1086 val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
1087 max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
1088
1089 return 0;
1090 }
1091
max310x_shutdown(struct uart_port * port)1092 static void max310x_shutdown(struct uart_port *port)
1093 {
1094 /* Disable all interrupts */
1095 max310x_port_write(port, MAX310X_IRQEN_REG, 0);
1096
1097 max310x_power(port, 0);
1098 }
1099
max310x_type(struct uart_port * port)1100 static const char *max310x_type(struct uart_port *port)
1101 {
1102 struct max310x_port *s = dev_get_drvdata(port->dev);
1103
1104 return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
1105 }
1106
max310x_request_port(struct uart_port * port)1107 static int max310x_request_port(struct uart_port *port)
1108 {
1109 /* Do nothing */
1110 return 0;
1111 }
1112
max310x_config_port(struct uart_port * port,int flags)1113 static void max310x_config_port(struct uart_port *port, int flags)
1114 {
1115 if (flags & UART_CONFIG_TYPE)
1116 port->type = PORT_MAX310X;
1117 }
1118
max310x_verify_port(struct uart_port * port,struct serial_struct * s)1119 static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
1120 {
1121 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
1122 return -EINVAL;
1123 if (s->irq != port->irq)
1124 return -EINVAL;
1125
1126 return 0;
1127 }
1128
max310x_null_void(struct uart_port * port)1129 static void max310x_null_void(struct uart_port *port)
1130 {
1131 /* Do nothing */
1132 }
1133
1134 static const struct uart_ops max310x_ops = {
1135 .tx_empty = max310x_tx_empty,
1136 .set_mctrl = max310x_set_mctrl,
1137 .get_mctrl = max310x_get_mctrl,
1138 .stop_tx = max310x_null_void,
1139 .start_tx = max310x_start_tx,
1140 .stop_rx = max310x_null_void,
1141 .break_ctl = max310x_break_ctl,
1142 .startup = max310x_startup,
1143 .shutdown = max310x_shutdown,
1144 .set_termios = max310x_set_termios,
1145 .type = max310x_type,
1146 .request_port = max310x_request_port,
1147 .release_port = max310x_null_void,
1148 .config_port = max310x_config_port,
1149 .verify_port = max310x_verify_port,
1150 };
1151
max310x_suspend(struct device * dev)1152 static int __maybe_unused max310x_suspend(struct device *dev)
1153 {
1154 struct max310x_port *s = dev_get_drvdata(dev);
1155 int i;
1156
1157 for (i = 0; i < s->devtype->nr; i++) {
1158 uart_suspend_port(&max310x_uart, &s->p[i].port);
1159 max310x_power(&s->p[i].port, 0);
1160 }
1161
1162 return 0;
1163 }
1164
max310x_resume(struct device * dev)1165 static int __maybe_unused max310x_resume(struct device *dev)
1166 {
1167 struct max310x_port *s = dev_get_drvdata(dev);
1168 int i;
1169
1170 for (i = 0; i < s->devtype->nr; i++) {
1171 max310x_power(&s->p[i].port, 1);
1172 uart_resume_port(&max310x_uart, &s->p[i].port);
1173 }
1174
1175 return 0;
1176 }
1177
1178 static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
1179
1180 #ifdef CONFIG_GPIOLIB
max310x_gpio_get(struct gpio_chip * chip,unsigned int offset)1181 static int max310x_gpio_get(struct gpio_chip *chip, unsigned int offset)
1182 {
1183 unsigned int val;
1184 struct max310x_port *s = gpiochip_get_data(chip);
1185 struct uart_port *port = &s->p[offset / 4].port;
1186
1187 val = max310x_port_read(port, MAX310X_GPIODATA_REG);
1188
1189 return !!((val >> 4) & (1 << (offset % 4)));
1190 }
1191
max310x_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)1192 static void max310x_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
1193 {
1194 struct max310x_port *s = gpiochip_get_data(chip);
1195 struct uart_port *port = &s->p[offset / 4].port;
1196
1197 max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1198 value ? 1 << (offset % 4) : 0);
1199 }
1200
max310x_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)1201 static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
1202 {
1203 struct max310x_port *s = gpiochip_get_data(chip);
1204 struct uart_port *port = &s->p[offset / 4].port;
1205
1206 max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
1207
1208 return 0;
1209 }
1210
max310x_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int value)1211 static int max310x_gpio_direction_output(struct gpio_chip *chip,
1212 unsigned int offset, int value)
1213 {
1214 struct max310x_port *s = gpiochip_get_data(chip);
1215 struct uart_port *port = &s->p[offset / 4].port;
1216
1217 max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1218 value ? 1 << (offset % 4) : 0);
1219 max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
1220 1 << (offset % 4));
1221
1222 return 0;
1223 }
1224
max310x_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)1225 static int max310x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
1226 unsigned long config)
1227 {
1228 struct max310x_port *s = gpiochip_get_data(chip);
1229 struct uart_port *port = &s->p[offset / 4].port;
1230
1231 switch (pinconf_to_config_param(config)) {
1232 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
1233 max310x_port_update(port, MAX310X_GPIOCFG_REG,
1234 1 << ((offset % 4) + 4),
1235 1 << ((offset % 4) + 4));
1236 return 0;
1237 case PIN_CONFIG_DRIVE_PUSH_PULL:
1238 max310x_port_update(port, MAX310X_GPIOCFG_REG,
1239 1 << ((offset % 4) + 4), 0);
1240 return 0;
1241 default:
1242 return -ENOTSUPP;
1243 }
1244 }
1245 #endif
1246
1247 static const struct serial_rs485 max310x_rs485_supported = {
1248 .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX,
1249 .delay_rts_before_send = 1,
1250 .delay_rts_after_send = 1,
1251 };
1252
max310x_probe(struct device * dev,const struct max310x_devtype * devtype,const struct max310x_if_cfg * if_cfg,struct regmap * regmaps[],int irq)1253 static int max310x_probe(struct device *dev, const struct max310x_devtype *devtype,
1254 const struct max310x_if_cfg *if_cfg,
1255 struct regmap *regmaps[], int irq)
1256 {
1257 int i, ret, fmin, fmax, freq;
1258 struct max310x_port *s;
1259 s32 uartclk = 0;
1260 bool xtal;
1261
1262 for (i = 0; i < devtype->nr; i++)
1263 if (IS_ERR(regmaps[i]))
1264 return PTR_ERR(regmaps[i]);
1265
1266 /* Alloc port structure */
1267 s = devm_kzalloc(dev, struct_size(s, p, devtype->nr), GFP_KERNEL);
1268 if (!s)
1269 return dev_err_probe(dev, -ENOMEM,
1270 "Error allocating port structure\n");
1271
1272 /* Always ask for fixed clock rate from a property. */
1273 device_property_read_u32(dev, "clock-frequency", &uartclk);
1274
1275 xtal = device_property_match_string(dev, "clock-names", "osc") < 0;
1276 if (xtal)
1277 s->clk = devm_clk_get_optional(dev, "xtal");
1278 else
1279 s->clk = devm_clk_get_optional(dev, "osc");
1280 if (IS_ERR(s->clk))
1281 return PTR_ERR(s->clk);
1282
1283 ret = clk_prepare_enable(s->clk);
1284 if (ret)
1285 return ret;
1286
1287 freq = clk_get_rate(s->clk);
1288 if (freq == 0)
1289 freq = uartclk;
1290 if (freq == 0) {
1291 ret = dev_err_probe(dev, -EINVAL, "Cannot get clock rate\n");
1292 goto out_clk;
1293 }
1294
1295 if (xtal) {
1296 fmin = 1000000;
1297 fmax = 4000000;
1298 } else {
1299 fmin = 500000;
1300 fmax = 35000000;
1301 }
1302
1303 /* Check frequency limits */
1304 if (freq < fmin || freq > fmax) {
1305 ret = -ERANGE;
1306 goto out_clk;
1307 }
1308
1309 s->regmap = regmaps[0];
1310 s->devtype = devtype;
1311 s->if_cfg = if_cfg;
1312 dev_set_drvdata(dev, s);
1313
1314 /* Check device to ensure we are talking to what we expect */
1315 ret = max310x_detect(dev);
1316 if (ret)
1317 goto out_clk;
1318
1319 for (i = 0; i < devtype->nr; i++) {
1320 bool started = false;
1321 unsigned int try = 0, val = 0;
1322
1323 /* Reset port */
1324 regmap_write(regmaps[i], MAX310X_MODE2_REG,
1325 MAX310X_MODE2_RST_BIT);
1326 /* Clear port reset */
1327 regmap_write(regmaps[i], MAX310X_MODE2_REG, 0);
1328
1329 /* Wait for port startup */
1330 do {
1331 msleep(MAX310X_PORT_STARTUP_WAIT_DELAY_MS);
1332 regmap_read(regmaps[i], MAX310X_BRGDIVLSB_REG, &val);
1333
1334 if (val == 0x01)
1335 started = true;
1336 } while (!started && (++try < MAX310X_PORT_STARTUP_WAIT_RETRIES));
1337
1338 if (!started) {
1339 ret = dev_err_probe(dev, -EAGAIN, "port reset failed\n");
1340 goto out_uart;
1341 }
1342
1343 regmap_write(regmaps[i], MAX310X_MODE1_REG, devtype->mode1);
1344 }
1345
1346 uartclk = max310x_set_ref_clk(dev, s, freq, xtal);
1347 if (uartclk < 0) {
1348 ret = uartclk;
1349 goto out_uart;
1350 }
1351
1352 dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
1353
1354 for (i = 0; i < devtype->nr; i++) {
1355 unsigned int line;
1356
1357 line = find_first_zero_bit(max310x_lines, MAX310X_UART_NRMAX);
1358 if (line == MAX310X_UART_NRMAX) {
1359 ret = -ERANGE;
1360 goto out_uart;
1361 }
1362
1363 /* Initialize port data */
1364 s->p[i].port.line = line;
1365 s->p[i].port.dev = dev;
1366 s->p[i].port.irq = irq;
1367 s->p[i].port.type = PORT_MAX310X;
1368 s->p[i].port.fifosize = MAX310X_FIFO_SIZE;
1369 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1370 s->p[i].port.iotype = UPIO_PORT;
1371 s->p[i].port.iobase = i;
1372 /*
1373 * Use all ones as membase to make sure uart_configure_port() in
1374 * serial_core.c does not abort for SPI/I2C devices where the
1375 * membase address is not applicable.
1376 */
1377 s->p[i].port.membase = (void __iomem *)~0;
1378 s->p[i].port.uartclk = uartclk;
1379 s->p[i].port.rs485_config = max310x_rs485_config;
1380 s->p[i].port.rs485_supported = max310x_rs485_supported;
1381 s->p[i].port.ops = &max310x_ops;
1382 s->p[i].regmap = regmaps[i];
1383
1384 /* Disable all interrupts */
1385 max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
1386 /* Clear IRQ status register */
1387 max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
1388 /* Initialize queue for start TX */
1389 INIT_WORK(&s->p[i].tx_work, max310x_tx_proc);
1390 /* Initialize queue for changing LOOPBACK mode */
1391 INIT_WORK(&s->p[i].md_work, max310x_md_proc);
1392 /* Initialize queue for changing RS485 mode */
1393 INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
1394
1395 /* Register port */
1396 ret = uart_add_one_port(&max310x_uart, &s->p[i].port);
1397 if (ret)
1398 goto out_uart;
1399
1400 set_bit(line, max310x_lines);
1401
1402 /* Go to suspend mode */
1403 max310x_power(&s->p[i].port, 0);
1404 }
1405
1406 #ifdef CONFIG_GPIOLIB
1407 /* Setup GPIO controller */
1408 s->gpio.owner = THIS_MODULE;
1409 s->gpio.parent = dev;
1410 s->gpio.label = devtype->name;
1411 s->gpio.direction_input = max310x_gpio_direction_input;
1412 s->gpio.get = max310x_gpio_get;
1413 s->gpio.direction_output= max310x_gpio_direction_output;
1414 s->gpio.set = max310x_gpio_set;
1415 s->gpio.set_config = max310x_gpio_set_config;
1416 s->gpio.base = -1;
1417 s->gpio.ngpio = devtype->nr * 4;
1418 s->gpio.can_sleep = 1;
1419 ret = devm_gpiochip_add_data(dev, &s->gpio, s);
1420 if (ret)
1421 goto out_uart;
1422 #endif
1423
1424 /* Setup interrupt */
1425 ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
1426 IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), s);
1427 if (!ret)
1428 return 0;
1429
1430 dev_err(dev, "Unable to request IRQ %i\n", irq);
1431
1432 out_uart:
1433 for (i = 0; i < devtype->nr; i++) {
1434 if (test_and_clear_bit(s->p[i].port.line, max310x_lines))
1435 uart_remove_one_port(&max310x_uart, &s->p[i].port);
1436 }
1437
1438 out_clk:
1439 clk_disable_unprepare(s->clk);
1440
1441 return ret;
1442 }
1443
max310x_remove(struct device * dev)1444 static void max310x_remove(struct device *dev)
1445 {
1446 struct max310x_port *s = dev_get_drvdata(dev);
1447 int i;
1448
1449 for (i = 0; i < s->devtype->nr; i++) {
1450 cancel_work_sync(&s->p[i].tx_work);
1451 cancel_work_sync(&s->p[i].md_work);
1452 cancel_work_sync(&s->p[i].rs_work);
1453
1454 if (test_and_clear_bit(s->p[i].port.line, max310x_lines))
1455 uart_remove_one_port(&max310x_uart, &s->p[i].port);
1456
1457 max310x_power(&s->p[i].port, 0);
1458 }
1459
1460 clk_disable_unprepare(s->clk);
1461 }
1462
1463 static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
1464 { .compatible = "maxim,max3107", .data = &max3107_devtype, },
1465 { .compatible = "maxim,max3108", .data = &max3108_devtype, },
1466 { .compatible = "maxim,max3109", .data = &max3109_devtype, },
1467 { .compatible = "maxim,max14830", .data = &max14830_devtype },
1468 { }
1469 };
1470 MODULE_DEVICE_TABLE(of, max310x_dt_ids);
1471
1472 static struct regmap_config regcfg = {
1473 .reg_bits = 8,
1474 .val_bits = 8,
1475 .write_flag_mask = MAX310X_WRITE_BIT,
1476 .cache_type = REGCACHE_MAPLE,
1477 .max_register = MAX310X_REG_1F,
1478 .writeable_reg = max310x_reg_writeable,
1479 .volatile_reg = max310x_reg_volatile,
1480 .precious_reg = max310x_reg_precious,
1481 .writeable_noinc_reg = max310x_reg_noinc,
1482 .readable_noinc_reg = max310x_reg_noinc,
1483 .max_raw_read = MAX310X_FIFO_SIZE,
1484 .max_raw_write = MAX310X_FIFO_SIZE,
1485 };
1486
max310x_regmap_name(u8 port_id)1487 static const char *max310x_regmap_name(u8 port_id)
1488 {
1489 switch (port_id) {
1490 case 0: return "port0";
1491 case 1: return "port1";
1492 case 2: return "port2";
1493 case 3: return "port3";
1494 default:
1495 WARN_ON(true);
1496 return NULL;
1497 }
1498 }
1499
1500 #ifdef CONFIG_SPI_MASTER
max310x_spi_extended_reg_enable(struct device * dev,bool enable)1501 static int max310x_spi_extended_reg_enable(struct device *dev, bool enable)
1502 {
1503 struct max310x_port *s = dev_get_drvdata(dev);
1504
1505 return regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
1506 enable ? MAX310X_EXTREG_ENBL : MAX310X_EXTREG_DSBL);
1507 }
1508
1509 static const struct max310x_if_cfg __maybe_unused max310x_spi_if_cfg = {
1510 .extended_reg_enable = max310x_spi_extended_reg_enable,
1511 .rev_id_offset = MAX310X_EXTREG_START,
1512 };
1513
max310x_spi_probe(struct spi_device * spi)1514 static int max310x_spi_probe(struct spi_device *spi)
1515 {
1516 const struct max310x_devtype *devtype;
1517 struct regmap *regmaps[MAX310X_MAX_PORTS];
1518 unsigned int i;
1519 int ret;
1520
1521 /* Setup SPI bus */
1522 spi->bits_per_word = 8;
1523 spi->mode = spi->mode ? : SPI_MODE_0;
1524 spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
1525 ret = spi_setup(spi);
1526 if (ret)
1527 return ret;
1528
1529 devtype = spi_get_device_match_data(spi);
1530 if (!devtype)
1531 return dev_err_probe(&spi->dev, -ENODEV, "Failed to match device\n");
1532
1533 for (i = 0; i < devtype->nr; i++) {
1534 u8 port_mask = i * 0x20;
1535
1536 regcfg.name = max310x_regmap_name(i);
1537 regcfg.read_flag_mask = port_mask;
1538 regcfg.write_flag_mask = port_mask | MAX310X_WRITE_BIT;
1539 regmaps[i] = devm_regmap_init_spi(spi, ®cfg);
1540 }
1541
1542 return max310x_probe(&spi->dev, devtype, &max310x_spi_if_cfg, regmaps, spi->irq);
1543 }
1544
max310x_spi_remove(struct spi_device * spi)1545 static void max310x_spi_remove(struct spi_device *spi)
1546 {
1547 max310x_remove(&spi->dev);
1548 }
1549
1550 static const struct spi_device_id max310x_id_table[] = {
1551 { "max3107", (kernel_ulong_t)&max3107_devtype, },
1552 { "max3108", (kernel_ulong_t)&max3108_devtype, },
1553 { "max3109", (kernel_ulong_t)&max3109_devtype, },
1554 { "max14830", (kernel_ulong_t)&max14830_devtype, },
1555 { }
1556 };
1557 MODULE_DEVICE_TABLE(spi, max310x_id_table);
1558
1559 static struct spi_driver max310x_spi_driver = {
1560 .driver = {
1561 .name = MAX310X_NAME,
1562 .of_match_table = max310x_dt_ids,
1563 .pm = &max310x_pm_ops,
1564 },
1565 .probe = max310x_spi_probe,
1566 .remove = max310x_spi_remove,
1567 .id_table = max310x_id_table,
1568 };
1569 #endif
1570
1571 #ifdef CONFIG_I2C
max310x_i2c_extended_reg_enable(struct device * dev,bool enable)1572 static int max310x_i2c_extended_reg_enable(struct device *dev, bool enable)
1573 {
1574 return 0;
1575 }
1576
1577 static struct regmap_config regcfg_i2c = {
1578 .reg_bits = 8,
1579 .val_bits = 8,
1580 .cache_type = REGCACHE_MAPLE,
1581 .writeable_reg = max310x_reg_writeable,
1582 .volatile_reg = max310x_reg_volatile,
1583 .precious_reg = max310x_reg_precious,
1584 .max_register = MAX310X_REVID_EXTREG,
1585 .writeable_noinc_reg = max310x_reg_noinc,
1586 .readable_noinc_reg = max310x_reg_noinc,
1587 .max_raw_read = MAX310X_FIFO_SIZE,
1588 .max_raw_write = MAX310X_FIFO_SIZE,
1589 };
1590
1591 static const struct max310x_if_cfg max310x_i2c_if_cfg = {
1592 .extended_reg_enable = max310x_i2c_extended_reg_enable,
1593 .rev_id_offset = 0, /* No offset in I2C mode. */
1594 };
1595
max310x_i2c_slave_addr(unsigned short addr,unsigned int nr)1596 static unsigned short max310x_i2c_slave_addr(unsigned short addr,
1597 unsigned int nr)
1598 {
1599 /*
1600 * For MAX14830 and MAX3109, the slave address depends on what the
1601 * A0 and A1 pins are tied to.
1602 * See Table I2C Address Map of the datasheet.
1603 * Based on that table, the following formulas were determined:
1604 * UART1 - UART0 = 0x10
1605 * UART2 - UART1 = 0x20 + 0x10
1606 * UART3 - UART2 = 0x10
1607 */
1608
1609 addr -= nr * 0x10;
1610
1611 if (nr >= 2)
1612 addr -= 0x20;
1613
1614 return addr;
1615 }
1616
max310x_i2c_probe(struct i2c_client * client)1617 static int max310x_i2c_probe(struct i2c_client *client)
1618 {
1619 const struct max310x_devtype *devtype;
1620 struct i2c_client *port_client;
1621 struct regmap *regmaps[MAX310X_MAX_PORTS];
1622 unsigned int i;
1623 u8 port_addr;
1624
1625 devtype = i2c_get_match_data(client);
1626 if (!devtype)
1627 return dev_err_probe(&client->dev, -ENODEV, "Failed to match device\n");
1628
1629 if (client->addr < devtype->slave_addr.min ||
1630 client->addr > devtype->slave_addr.max)
1631 return dev_err_probe(&client->dev, -EINVAL,
1632 "Slave addr 0x%x outside of range [0x%x, 0x%x]\n",
1633 client->addr, devtype->slave_addr.min,
1634 devtype->slave_addr.max);
1635
1636 regcfg_i2c.name = max310x_regmap_name(0);
1637 regmaps[0] = devm_regmap_init_i2c(client, ®cfg_i2c);
1638
1639 for (i = 1; i < devtype->nr; i++) {
1640 port_addr = max310x_i2c_slave_addr(client->addr, i);
1641 port_client = devm_i2c_new_dummy_device(&client->dev,
1642 client->adapter,
1643 port_addr);
1644
1645 regcfg_i2c.name = max310x_regmap_name(i);
1646 regmaps[i] = devm_regmap_init_i2c(port_client, ®cfg_i2c);
1647 }
1648
1649 return max310x_probe(&client->dev, devtype, &max310x_i2c_if_cfg,
1650 regmaps, client->irq);
1651 }
1652
max310x_i2c_remove(struct i2c_client * client)1653 static void max310x_i2c_remove(struct i2c_client *client)
1654 {
1655 max310x_remove(&client->dev);
1656 }
1657
1658 static const struct i2c_device_id max310x_i2c_id_table[] = {
1659 { "max3107", (kernel_ulong_t)&max3107_devtype, },
1660 { "max3108", (kernel_ulong_t)&max3108_devtype, },
1661 { "max3109", (kernel_ulong_t)&max3109_devtype, },
1662 { "max14830", (kernel_ulong_t)&max14830_devtype, },
1663 { }
1664 };
1665 MODULE_DEVICE_TABLE(i2c, max310x_i2c_id_table);
1666
1667 static struct i2c_driver max310x_i2c_driver = {
1668 .driver = {
1669 .name = MAX310X_NAME,
1670 .of_match_table = max310x_dt_ids,
1671 .pm = &max310x_pm_ops,
1672 },
1673 .probe = max310x_i2c_probe,
1674 .remove = max310x_i2c_remove,
1675 .id_table = max310x_i2c_id_table,
1676 };
1677 #endif
1678
max310x_uart_init(void)1679 static int __init max310x_uart_init(void)
1680 {
1681 int ret;
1682
1683 bitmap_zero(max310x_lines, MAX310X_UART_NRMAX);
1684
1685 ret = uart_register_driver(&max310x_uart);
1686 if (ret)
1687 return ret;
1688
1689 #ifdef CONFIG_SPI_MASTER
1690 ret = spi_register_driver(&max310x_spi_driver);
1691 if (ret)
1692 goto err_spi_register;
1693 #endif
1694
1695 #ifdef CONFIG_I2C
1696 ret = i2c_add_driver(&max310x_i2c_driver);
1697 if (ret)
1698 goto err_i2c_register;
1699 #endif
1700
1701 return 0;
1702
1703 #ifdef CONFIG_I2C
1704 err_i2c_register:
1705 spi_unregister_driver(&max310x_spi_driver);
1706 #endif
1707
1708 err_spi_register:
1709 uart_unregister_driver(&max310x_uart);
1710
1711 return ret;
1712 }
1713 module_init(max310x_uart_init);
1714
max310x_uart_exit(void)1715 static void __exit max310x_uart_exit(void)
1716 {
1717 #ifdef CONFIG_I2C
1718 i2c_del_driver(&max310x_i2c_driver);
1719 #endif
1720
1721 #ifdef CONFIG_SPI_MASTER
1722 spi_unregister_driver(&max310x_spi_driver);
1723 #endif
1724
1725 uart_unregister_driver(&max310x_uart);
1726 }
1727 module_exit(max310x_uart_exit);
1728
1729 MODULE_LICENSE("GPL");
1730 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1731 MODULE_DESCRIPTION("MAX310X serial driver");
1732