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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / tty / serial / max310x.c
blob9795b2e8b0b2cc96ed2a1f5b2a5b6ca5f72da887
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Maxim (Dallas) MAX3107/8/9, MAX14830 serial driver
4 *
5 * Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
6 *
7 * Based on max3100.c, by Christian Pellegrin <chripell@evolware.org>
8 * Based on max3110.c, by Feng Tang <feng.tang@intel.com>
9 * Based on max3107.c, by Aavamobile
10 */
11
12 #include <linux/bitops.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/device.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/property.h>
20 #include <linux/regmap.h>
21 #include <linux/serial_core.h>
22 #include <linux/serial.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 #include <linux/spi/spi.h>
26 #include <linux/uaccess.h>
27
28 #define MAX310X_NAME "max310x"
29 #define MAX310X_MAJOR 204
30 #define MAX310X_MINOR 209
31 #define MAX310X_UART_NRMAX 16
32
33 /* MAX310X register definitions */
34 #define MAX310X_RHR_REG (0x00) /* RX FIFO */
35 #define MAX310X_THR_REG (0x00) /* TX FIFO */
36 #define MAX310X_IRQEN_REG (0x01) /* IRQ enable */
37 #define MAX310X_IRQSTS_REG (0x02) /* IRQ status */
38 #define MAX310X_LSR_IRQEN_REG (0x03) /* LSR IRQ enable */
39 #define MAX310X_LSR_IRQSTS_REG (0x04) /* LSR IRQ status */
40 #define MAX310X_REG_05 (0x05)
41 #define MAX310X_SPCHR_IRQEN_REG MAX310X_REG_05 /* Special char IRQ en */
42 #define MAX310X_SPCHR_IRQSTS_REG (0x06) /* Special char IRQ status */
43 #define MAX310X_STS_IRQEN_REG (0x07) /* Status IRQ enable */
44 #define MAX310X_STS_IRQSTS_REG (0x08) /* Status IRQ status */
45 #define MAX310X_MODE1_REG (0x09) /* MODE1 */
46 #define MAX310X_MODE2_REG (0x0a) /* MODE2 */
47 #define MAX310X_LCR_REG (0x0b) /* LCR */
48 #define MAX310X_RXTO_REG (0x0c) /* RX timeout */
49 #define MAX310X_HDPIXDELAY_REG (0x0d) /* Auto transceiver delays */
50 #define MAX310X_IRDA_REG (0x0e) /* IRDA settings */
51 #define MAX310X_FLOWLVL_REG (0x0f) /* Flow control levels */
52 #define MAX310X_FIFOTRIGLVL_REG (0x10) /* FIFO IRQ trigger levels */
53 #define MAX310X_TXFIFOLVL_REG (0x11) /* TX FIFO level */
54 #define MAX310X_RXFIFOLVL_REG (0x12) /* RX FIFO level */
55 #define MAX310X_FLOWCTRL_REG (0x13) /* Flow control */
56 #define MAX310X_XON1_REG (0x14) /* XON1 character */
57 #define MAX310X_XON2_REG (0x15) /* XON2 character */
58 #define MAX310X_XOFF1_REG (0x16) /* XOFF1 character */
59 #define MAX310X_XOFF2_REG (0x17) /* XOFF2 character */
60 #define MAX310X_GPIOCFG_REG (0x18) /* GPIO config */
61 #define MAX310X_GPIODATA_REG (0x19) /* GPIO data */
62 #define MAX310X_PLLCFG_REG (0x1a) /* PLL config */
63 #define MAX310X_BRGCFG_REG (0x1b) /* Baud rate generator conf */
64 #define MAX310X_BRGDIVLSB_REG (0x1c) /* Baud rate divisor LSB */
65 #define MAX310X_BRGDIVMSB_REG (0x1d) /* Baud rate divisor MSB */
66 #define MAX310X_CLKSRC_REG (0x1e) /* Clock source */
67 #define MAX310X_REG_1F (0x1f)
68
69 #define MAX310X_REVID_REG MAX310X_REG_1F /* Revision ID */
70
71 #define MAX310X_GLOBALIRQ_REG MAX310X_REG_1F /* Global IRQ (RO) */
72 #define MAX310X_GLOBALCMD_REG MAX310X_REG_1F /* Global Command (WO) */
73
74 /* Extended registers */
75 #define MAX310X_REVID_EXTREG MAX310X_REG_05 /* Revision ID */
76
77 /* IRQ register bits */
78 #define MAX310X_IRQ_LSR_BIT (1 << 0) /* LSR interrupt */
79 #define MAX310X_IRQ_SPCHR_BIT (1 << 1) /* Special char interrupt */
80 #define MAX310X_IRQ_STS_BIT (1 << 2) /* Status interrupt */
81 #define MAX310X_IRQ_RXFIFO_BIT (1 << 3) /* RX FIFO interrupt */
82 #define MAX310X_IRQ_TXFIFO_BIT (1 << 4) /* TX FIFO interrupt */
83 #define MAX310X_IRQ_TXEMPTY_BIT (1 << 5) /* TX FIFO empty interrupt */
84 #define MAX310X_IRQ_RXEMPTY_BIT (1 << 6) /* RX FIFO empty interrupt */
85 #define MAX310X_IRQ_CTS_BIT (1 << 7) /* CTS interrupt */
86
87 /* LSR register bits */
88 #define MAX310X_LSR_RXTO_BIT (1 << 0) /* RX timeout */
89 #define MAX310X_LSR_RXOVR_BIT (1 << 1) /* RX overrun */
90 #define MAX310X_LSR_RXPAR_BIT (1 << 2) /* RX parity error */
91 #define MAX310X_LSR_FRERR_BIT (1 << 3) /* Frame error */
92 #define MAX310X_LSR_RXBRK_BIT (1 << 4) /* RX break */
93 #define MAX310X_LSR_RXNOISE_BIT (1 << 5) /* RX noise */
94 #define MAX310X_LSR_CTS_BIT (1 << 7) /* CTS pin state */
95
96 /* Special character register bits */
97 #define MAX310X_SPCHR_XON1_BIT (1 << 0) /* XON1 character */
98 #define MAX310X_SPCHR_XON2_BIT (1 << 1) /* XON2 character */
99 #define MAX310X_SPCHR_XOFF1_BIT (1 << 2) /* XOFF1 character */
100 #define MAX310X_SPCHR_XOFF2_BIT (1 << 3) /* XOFF2 character */
101 #define MAX310X_SPCHR_BREAK_BIT (1 << 4) /* RX break */
102 #define MAX310X_SPCHR_MULTIDROP_BIT (1 << 5) /* 9-bit multidrop addr char */
103
104 /* Status register bits */
105 #define MAX310X_STS_GPIO0_BIT (1 << 0) /* GPIO 0 interrupt */
106 #define MAX310X_STS_GPIO1_BIT (1 << 1) /* GPIO 1 interrupt */
107 #define MAX310X_STS_GPIO2_BIT (1 << 2) /* GPIO 2 interrupt */
108 #define MAX310X_STS_GPIO3_BIT (1 << 3) /* GPIO 3 interrupt */
109 #define MAX310X_STS_CLKREADY_BIT (1 << 5) /* Clock ready */
110 #define MAX310X_STS_SLEEP_BIT (1 << 6) /* Sleep interrupt */
111
112 /* MODE1 register bits */
113 #define MAX310X_MODE1_RXDIS_BIT (1 << 0) /* RX disable */
114 #define MAX310X_MODE1_TXDIS_BIT (1 << 1) /* TX disable */
115 #define MAX310X_MODE1_TXHIZ_BIT (1 << 2) /* TX pin three-state */
116 #define MAX310X_MODE1_RTSHIZ_BIT (1 << 3) /* RTS pin three-state */
117 #define MAX310X_MODE1_TRNSCVCTRL_BIT (1 << 4) /* Transceiver ctrl enable */
118 #define MAX310X_MODE1_FORCESLEEP_BIT (1 << 5) /* Force sleep mode */
119 #define MAX310X_MODE1_AUTOSLEEP_BIT (1 << 6) /* Auto sleep enable */
120 #define MAX310X_MODE1_IRQSEL_BIT (1 << 7) /* IRQ pin enable */
121
122 /* MODE2 register bits */
123 #define MAX310X_MODE2_RST_BIT (1 << 0) /* Chip reset */
124 #define MAX310X_MODE2_FIFORST_BIT (1 << 1) /* FIFO reset */
125 #define MAX310X_MODE2_RXTRIGINV_BIT (1 << 2) /* RX FIFO INT invert */
126 #define MAX310X_MODE2_RXEMPTINV_BIT (1 << 3) /* RX FIFO empty INT invert */
127 #define MAX310X_MODE2_SPCHR_BIT (1 << 4) /* Special chr detect enable */
128 #define MAX310X_MODE2_LOOPBACK_BIT (1 << 5) /* Internal loopback enable */
129 #define MAX310X_MODE2_MULTIDROP_BIT (1 << 6) /* 9-bit multidrop enable */
130 #define MAX310X_MODE2_ECHOSUPR_BIT (1 << 7) /* ECHO suppression enable */
131
132 /* LCR register bits */
133 #define MAX310X_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */
134 #define MAX310X_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1
135 *
136 * Word length bits table:
137 * 00 -> 5 bit words
138 * 01 -> 6 bit words
139 * 10 -> 7 bit words
140 * 11 -> 8 bit words
141 */
142 #define MAX310X_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
143 *
144 * STOP length bit table:
145 * 0 -> 1 stop bit
146 * 1 -> 1-1.5 stop bits if
147 * word length is 5,
148 * 2 stop bits otherwise
149 */
150 #define MAX310X_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */
151 #define MAX310X_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */
152 #define MAX310X_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */
153 #define MAX310X_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */
154 #define MAX310X_LCR_RTS_BIT (1 << 7) /* RTS pin control */
155
156 /* IRDA register bits */
157 #define MAX310X_IRDA_IRDAEN_BIT (1 << 0) /* IRDA mode enable */
158 #define MAX310X_IRDA_SIR_BIT (1 << 1) /* SIR mode enable */
159
160 /* Flow control trigger level register masks */
161 #define MAX310X_FLOWLVL_HALT_MASK (0x000f) /* Flow control halt level */
162 #define MAX310X_FLOWLVL_RES_MASK (0x00f0) /* Flow control resume level */
163 #define MAX310X_FLOWLVL_HALT(words) ((words / 8) & 0x0f)
164 #define MAX310X_FLOWLVL_RES(words) (((words / 8) & 0x0f) << 4)
165
166 /* FIFO interrupt trigger level register masks */
167 #define MAX310X_FIFOTRIGLVL_TX_MASK (0x0f) /* TX FIFO trigger level */
168 #define MAX310X_FIFOTRIGLVL_RX_MASK (0xf0) /* RX FIFO trigger level */
169 #define MAX310X_FIFOTRIGLVL_TX(words) ((words / 8) & 0x0f)
170 #define MAX310X_FIFOTRIGLVL_RX(words) (((words / 8) & 0x0f) << 4)
171
172 /* Flow control register bits */
173 #define MAX310X_FLOWCTRL_AUTORTS_BIT (1 << 0) /* Auto RTS flow ctrl enable */
174 #define MAX310X_FLOWCTRL_AUTOCTS_BIT (1 << 1) /* Auto CTS flow ctrl enable */
175 #define MAX310X_FLOWCTRL_GPIADDR_BIT (1 << 2) /* Enables that GPIO inputs
176 * are used in conjunction with
177 * XOFF2 for definition of
178 * special character */
179 #define MAX310X_FLOWCTRL_SWFLOWEN_BIT (1 << 3) /* Auto SW flow ctrl enable */
180 #define MAX310X_FLOWCTRL_SWFLOW0_BIT (1 << 4) /* SWFLOW bit 0 */
181 #define MAX310X_FLOWCTRL_SWFLOW1_BIT (1 << 5) /* SWFLOW bit 1
182 *
183 * SWFLOW bits 1 & 0 table:
184 * 00 -> no transmitter flow
185 * control
186 * 01 -> receiver compares
187 * XON2 and XOFF2
188 * and controls
189 * transmitter
190 * 10 -> receiver compares
191 * XON1 and XOFF1
192 * and controls
193 * transmitter
194 * 11 -> receiver compares
195 * XON1, XON2, XOFF1 and
196 * XOFF2 and controls
197 * transmitter
198 */
199 #define MAX310X_FLOWCTRL_SWFLOW2_BIT (1 << 6) /* SWFLOW bit 2 */
200 #define MAX310X_FLOWCTRL_SWFLOW3_BIT (1 << 7) /* SWFLOW bit 3
201 *
202 * SWFLOW bits 3 & 2 table:
203 * 00 -> no received flow
204 * control
205 * 01 -> transmitter generates
206 * XON2 and XOFF2
207 * 10 -> transmitter generates
208 * XON1 and XOFF1
209 * 11 -> transmitter generates
210 * XON1, XON2, XOFF1 and
211 * XOFF2
212 */
213
214 /* PLL configuration register masks */
215 #define MAX310X_PLLCFG_PREDIV_MASK (0x3f) /* PLL predivision value */
216 #define MAX310X_PLLCFG_PLLFACTOR_MASK (0xc0) /* PLL multiplication factor */
217
218 /* Baud rate generator configuration register bits */
219 #define MAX310X_BRGCFG_2XMODE_BIT (1 << 4) /* Double baud rate */
220 #define MAX310X_BRGCFG_4XMODE_BIT (1 << 5) /* Quadruple baud rate */
221
222 /* Clock source register bits */
223 #define MAX310X_CLKSRC_CRYST_BIT (1 << 1) /* Crystal osc enable */
224 #define MAX310X_CLKSRC_PLL_BIT (1 << 2) /* PLL enable */
225 #define MAX310X_CLKSRC_PLLBYP_BIT (1 << 3) /* PLL bypass */
226 #define MAX310X_CLKSRC_EXTCLK_BIT (1 << 4) /* External clock enable */
227 #define MAX310X_CLKSRC_CLK2RTS_BIT (1 << 7) /* Baud clk to RTS pin */
228
229 /* Global commands */
230 #define MAX310X_EXTREG_ENBL (0xce)
231 #define MAX310X_EXTREG_DSBL (0xcd)
232
233 /* Misc definitions */
234 #define MAX310X_FIFO_SIZE (128)
235 #define MAX310x_REV_MASK (0xf8)
236 #define MAX310X_WRITE_BIT 0x80
237
238 /* MAX3107 specific */
239 #define MAX3107_REV_ID (0xa0)
240
241 /* MAX3109 specific */
242 #define MAX3109_REV_ID (0xc0)
243
244 /* MAX14830 specific */
245 #define MAX14830_BRGCFG_CLKDIS_BIT (1 << 6) /* Clock Disable */
246 #define MAX14830_REV_ID (0xb0)
247
248 struct max310x_devtype {
249 char name[9];
250 int nr;
251 u8 mode1;
252 int (*detect)(struct device *);
253 void (*power)(struct uart_port *, int);
254 };
255
256 struct max310x_one {
257 struct uart_port port;
258 struct work_struct tx_work;
259 struct work_struct md_work;
260 struct work_struct rs_work;
261
262 u8 wr_header;
263 u8 rd_header;
264 u8 rx_buf[MAX310X_FIFO_SIZE];
265 };
266 #define to_max310x_port(_port) \
267 container_of(_port, struct max310x_one, port)
268
269 struct max310x_port {
270 const struct max310x_devtype *devtype;
271 struct regmap *regmap;
272 struct clk *clk;
273 #ifdef CONFIG_GPIOLIB
274 struct gpio_chip gpio;
275 #endif
276 struct max310x_one p[0];
277 };
278
279 static struct uart_driver max310x_uart = {
280 .owner = THIS_MODULE,
281 .driver_name = MAX310X_NAME,
282 .dev_name = "ttyMAX",
283 .major = MAX310X_MAJOR,
284 .minor = MAX310X_MINOR,
285 .nr = MAX310X_UART_NRMAX,
286 };
287
288 static DECLARE_BITMAP(max310x_lines, MAX310X_UART_NRMAX);
289
290 static u8 max310x_port_read(struct uart_port *port, u8 reg)
291 {
292 struct max310x_port *s = dev_get_drvdata(port->dev);
293 unsigned int val = 0;
294
295 regmap_read(s->regmap, port->iobase + reg, &val);
296
297 return val;
298 }
299
300 static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
301 {
302 struct max310x_port *s = dev_get_drvdata(port->dev);
303
304 regmap_write(s->regmap, port->iobase + reg, val);
305 }
306
307 static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
308 {
309 struct max310x_port *s = dev_get_drvdata(port->dev);
310
311 regmap_update_bits(s->regmap, port->iobase + reg, mask, val);
312 }
313
314 static int max3107_detect(struct device *dev)
315 {
316 struct max310x_port *s = dev_get_drvdata(dev);
317 unsigned int val = 0;
318 int ret;
319
320 ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val);
321 if (ret)
322 return ret;
323
324 if (((val & MAX310x_REV_MASK) != MAX3107_REV_ID)) {
325 dev_err(dev,
326 "%s ID 0x%02x does not match\n", s->devtype->name, val);
327 return -ENODEV;
328 }
329
330 return 0;
331 }
332
333 static int max3108_detect(struct device *dev)
334 {
335 struct max310x_port *s = dev_get_drvdata(dev);
336 unsigned int val = 0;
337 int ret;
338
339 /* MAX3108 have not REV ID register, we just check default value
340 * from clocksource register to make sure everything works.
341 */
342 ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val);
343 if (ret)
344 return ret;
345
346 if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) {
347 dev_err(dev, "%s not present\n", s->devtype->name);
348 return -ENODEV;
349 }
350
351 return 0;
352 }
353
354 static int max3109_detect(struct device *dev)
355 {
356 struct max310x_port *s = dev_get_drvdata(dev);
357 unsigned int val = 0;
358 int ret;
359
360 ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
361 MAX310X_EXTREG_ENBL);
362 if (ret)
363 return ret;
364
365 regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
366 regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
367 if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
368 dev_err(dev,
369 "%s ID 0x%02x does not match\n", s->devtype->name, val);
370 return -ENODEV;
371 }
372
373 return 0;
374 }
375
376 static void max310x_power(struct uart_port *port, int on)
377 {
378 max310x_port_update(port, MAX310X_MODE1_REG,
379 MAX310X_MODE1_FORCESLEEP_BIT,
380 on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT);
381 if (on)
382 msleep(50);
383 }
384
385 static int max14830_detect(struct device *dev)
386 {
387 struct max310x_port *s = dev_get_drvdata(dev);
388 unsigned int val = 0;
389 int ret;
390
391 ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
392 MAX310X_EXTREG_ENBL);
393 if (ret)
394 return ret;
395
396 regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
397 regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
398 if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
399 dev_err(dev,
400 "%s ID 0x%02x does not match\n", s->devtype->name, val);
401 return -ENODEV;
402 }
403
404 return 0;
405 }
406
407 static void max14830_power(struct uart_port *port, int on)
408 {
409 max310x_port_update(port, MAX310X_BRGCFG_REG,
410 MAX14830_BRGCFG_CLKDIS_BIT,
411 on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT);
412 if (on)
413 msleep(50);
414 }
415
416 static const struct max310x_devtype max3107_devtype = {
417 .name = "MAX3107",
418 .nr = 1,
419 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT | MAX310X_MODE1_IRQSEL_BIT,
420 .detect = max3107_detect,
421 .power = max310x_power,
422 };
423
424 static const struct max310x_devtype max3108_devtype = {
425 .name = "MAX3108",
426 .nr = 1,
427 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT,
428 .detect = max3108_detect,
429 .power = max310x_power,
430 };
431
432 static const struct max310x_devtype max3109_devtype = {
433 .name = "MAX3109",
434 .nr = 2,
435 .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT,
436 .detect = max3109_detect,
437 .power = max310x_power,
438 };
439
440 static const struct max310x_devtype max14830_devtype = {
441 .name = "MAX14830",
442 .nr = 4,
443 .mode1 = MAX310X_MODE1_IRQSEL_BIT,
444 .detect = max14830_detect,
445 .power = max14830_power,
446 };
447
448 static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
449 {
450 switch (reg & 0x1f) {
451 case MAX310X_IRQSTS_REG:
452 case MAX310X_LSR_IRQSTS_REG:
453 case MAX310X_SPCHR_IRQSTS_REG:
454 case MAX310X_STS_IRQSTS_REG:
455 case MAX310X_TXFIFOLVL_REG:
456 case MAX310X_RXFIFOLVL_REG:
457 return false;
458 default:
459 break;
460 }
461
462 return true;
463 }
464
465 static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
466 {
467 switch (reg & 0x1f) {
468 case MAX310X_RHR_REG:
469 case MAX310X_IRQSTS_REG:
470 case MAX310X_LSR_IRQSTS_REG:
471 case MAX310X_SPCHR_IRQSTS_REG:
472 case MAX310X_STS_IRQSTS_REG:
473 case MAX310X_TXFIFOLVL_REG:
474 case MAX310X_RXFIFOLVL_REG:
475 case MAX310X_GPIODATA_REG:
476 case MAX310X_BRGDIVLSB_REG:
477 case MAX310X_REG_05:
478 case MAX310X_REG_1F:
479 return true;
480 default:
481 break;
482 }
483
484 return false;
485 }
486
487 static bool max310x_reg_precious(struct device *dev, unsigned int reg)
488 {
489 switch (reg & 0x1f) {
490 case MAX310X_RHR_REG:
491 case MAX310X_IRQSTS_REG:
492 case MAX310X_SPCHR_IRQSTS_REG:
493 case MAX310X_STS_IRQSTS_REG:
494 return true;
495 default:
496 break;
497 }
498
499 return false;
500 }
501
502 static int max310x_set_baud(struct uart_port *port, int baud)
503 {
504 unsigned int mode = 0, div = 0, frac = 0, c = 0, F = 0;
505
506 /*
507 * Calculate the integer divisor first. Select a proper mode
508 * in case if the requested baud is too high for the pre-defined
509 * clocks frequency.
510 */
511 div = port->uartclk / baud;
512 if (div < 8) {
513 /* Mode x4 */
514 c = 4;
515 mode = MAX310X_BRGCFG_4XMODE_BIT;
516 } else if (div < 16) {
517 /* Mode x2 */
518 c = 8;
519 mode = MAX310X_BRGCFG_2XMODE_BIT;
520 } else {
521 c = 16;
522 }
523
524 /* Calculate the divisor in accordance with the fraction coefficient */
525 div /= c;
526 F = c*baud;
527
528 /* Calculate the baud rate fraction */
529 if (div > 0)
530 frac = (16*(port->uartclk % F)) / F;
531 else
532 div = 1;
533
534 max310x_port_write(port, MAX310X_BRGDIVMSB_REG, div >> 8);
535 max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div);
536 max310x_port_write(port, MAX310X_BRGCFG_REG, frac | mode);
537
538 /* Return the actual baud rate we just programmed */
539 return (16*port->uartclk) / (c*(16*div + frac));
540 }
541
542 static int max310x_update_best_err(unsigned long f, long *besterr)
543 {
544 /* Use baudrate 115200 for calculate error */
545 long err = f % (460800 * 16);
546
547 if ((*besterr < 0) || (*besterr > err)) {
548 *besterr = err;
549 return 0;
550 }
551
552 return 1;
553 }
554
555 static int max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
556 unsigned long freq, bool xtal)
557 {
558 unsigned int div, clksrc, pllcfg = 0;
559 long besterr = -1;
560 unsigned long fdiv, fmul, bestfreq = freq;
561
562 /* First, update error without PLL */
563 max310x_update_best_err(freq, &besterr);
564
565 /* Try all possible PLL dividers */
566 for (div = 1; (div <= 63) && besterr; div++) {
567 fdiv = DIV_ROUND_CLOSEST(freq, div);
568
569 /* Try multiplier 6 */
570 fmul = fdiv * 6;
571 if ((fdiv >= 500000) && (fdiv <= 800000))
572 if (!max310x_update_best_err(fmul, &besterr)) {
573 pllcfg = (0 << 6) | div;
574 bestfreq = fmul;
575 }
576 /* Try multiplier 48 */
577 fmul = fdiv * 48;
578 if ((fdiv >= 850000) && (fdiv <= 1200000))
579 if (!max310x_update_best_err(fmul, &besterr)) {
580 pllcfg = (1 << 6) | div;
581 bestfreq = fmul;
582 }
583 /* Try multiplier 96 */
584 fmul = fdiv * 96;
585 if ((fdiv >= 425000) && (fdiv <= 1000000))
586 if (!max310x_update_best_err(fmul, &besterr)) {
587 pllcfg = (2 << 6) | div;
588 bestfreq = fmul;
589 }
590 /* Try multiplier 144 */
591 fmul = fdiv * 144;
592 if ((fdiv >= 390000) && (fdiv <= 667000))
593 if (!max310x_update_best_err(fmul, &besterr)) {
594 pllcfg = (3 << 6) | div;
595 bestfreq = fmul;
596 }
597 }
598
599 /* Configure clock source */
600 clksrc = MAX310X_CLKSRC_EXTCLK_BIT | (xtal ? MAX310X_CLKSRC_CRYST_BIT : 0);
601
602 /* Configure PLL */
603 if (pllcfg) {
604 clksrc |= MAX310X_CLKSRC_PLL_BIT;
605 regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
606 } else
607 clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
608
609 regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
610
611 /* Wait for crystal */
612 if (xtal) {
613 unsigned int val;
614 msleep(10);
615 regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
616 if (!(val & MAX310X_STS_CLKREADY_BIT)) {
617 dev_warn(dev, "clock is not stable yet\n");
618 }
619 }
620
621 return (int)bestfreq;
622 }
623
624 static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
625 {
626 struct max310x_one *one = to_max310x_port(port);
627 struct spi_transfer xfer[] = {
628 {
629 .tx_buf = &one->wr_header,
630 .len = sizeof(one->wr_header),
631 }, {
632 .tx_buf = txbuf,
633 .len = len,
634 }
635 };
636 spi_sync_transfer(to_spi_device(port->dev), xfer, ARRAY_SIZE(xfer));
637 }
638
639 static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
640 {
641 struct max310x_one *one = to_max310x_port(port);
642 struct spi_transfer xfer[] = {
643 {
644 .tx_buf = &one->rd_header,
645 .len = sizeof(one->rd_header),
646 }, {
647 .rx_buf = rxbuf,
648 .len = len,
649 }
650 };
651 spi_sync_transfer(to_spi_device(port->dev), xfer, ARRAY_SIZE(xfer));
652 }
653
654 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
655 {
656 struct max310x_one *one = to_max310x_port(port);
657 unsigned int sts, ch, flag, i;
658
659 if (port->read_status_mask == MAX310X_LSR_RXOVR_BIT) {
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
748 static void max310x_handle_tx(struct uart_port *port)
749 {
750 struct circ_buf *xmit = &port->state->xmit;
751 unsigned int txlen, to_send, until_end;
752
753 if (unlikely(port->x_char)) {
754 max310x_port_write(port, MAX310X_THR_REG, port->x_char);
755 port->icount.tx++;
756 port->x_char = 0;
757 return;
758 }
759
760 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
761 return;
762
763 /* Get length of data pending in circular buffer */
764 to_send = uart_circ_chars_pending(xmit);
765 until_end = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
766 if (likely(to_send)) {
767 /* Limit to size of TX FIFO */
768 txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
769 txlen = port->fifosize - txlen;
770 to_send = (to_send > txlen) ? txlen : to_send;
771
772 if (until_end < to_send) {
773 /* It's a circ buffer -- wrap around.
774 * We could do that in one SPI transaction, but meh. */
775 max310x_batch_write(port, xmit->buf + xmit->tail, until_end);
776 max310x_batch_write(port, xmit->buf, to_send - until_end);
777 } else {
778 max310x_batch_write(port, xmit->buf + xmit->tail, to_send);
779 }
780
781 /* Add data to send */
782 port->icount.tx += to_send;
783 xmit->tail = (xmit->tail + to_send) & (UART_XMIT_SIZE - 1);
784 }
785
786 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
787 uart_write_wakeup(port);
788 }
789
790 static void max310x_start_tx(struct uart_port *port)
791 {
792 struct max310x_one *one = to_max310x_port(port);
793
794 schedule_work(&one->tx_work);
795 }
796
797 static irqreturn_t max310x_port_irq(struct max310x_port *s, int portno)
798 {
799 struct uart_port *port = &s->p[portno].port;
800 irqreturn_t res = IRQ_NONE;
801
802 do {
803 unsigned int ists, lsr, rxlen;
804
805 /* Read IRQ status & RX FIFO level */
806 ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
807 rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
808 if (!ists && !rxlen)
809 break;
810
811 res = IRQ_HANDLED;
812
813 if (ists & MAX310X_IRQ_CTS_BIT) {
814 lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
815 uart_handle_cts_change(port,
816 !!(lsr & MAX310X_LSR_CTS_BIT));
817 }
818 if (rxlen)
819 max310x_handle_rx(port, rxlen);
820 if (ists & MAX310X_IRQ_TXEMPTY_BIT)
821 max310x_start_tx(port);
822 } while (1);
823 return res;
824 }
825
826 static irqreturn_t max310x_ist(int irq, void *dev_id)
827 {
828 struct max310x_port *s = (struct max310x_port *)dev_id;
829 bool handled = false;
830
831 if (s->devtype->nr > 1) {
832 do {
833 unsigned int val = ~0;
834
835 WARN_ON_ONCE(regmap_read(s->regmap,
836 MAX310X_GLOBALIRQ_REG, &val));
837 val = ((1 << s->devtype->nr) - 1) & ~val;
838 if (!val)
839 break;
840 if (max310x_port_irq(s, fls(val) - 1) == IRQ_HANDLED)
841 handled = true;
842 } while (1);
843 } else {
844 if (max310x_port_irq(s, 0) == IRQ_HANDLED)
845 handled = true;
846 }
847
848 return IRQ_RETVAL(handled);
849 }
850
851 static void max310x_tx_proc(struct work_struct *ws)
852 {
853 struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
854
855 max310x_handle_tx(&one->port);
856 }
857
858 static unsigned int max310x_tx_empty(struct uart_port *port)
859 {
860 u8 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
861
862 return lvl ? 0 : TIOCSER_TEMT;
863 }
864
865 static unsigned int max310x_get_mctrl(struct uart_port *port)
866 {
867 /* DCD and DSR are not wired and CTS/RTS is handled automatically
868 * so just indicate DSR and CAR asserted
869 */
870 return TIOCM_DSR | TIOCM_CAR;
871 }
872
873 static void max310x_md_proc(struct work_struct *ws)
874 {
875 struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
876
877 max310x_port_update(&one->port, MAX310X_MODE2_REG,
878 MAX310X_MODE2_LOOPBACK_BIT,
879 (one->port.mctrl & TIOCM_LOOP) ?
880 MAX310X_MODE2_LOOPBACK_BIT : 0);
881 }
882
883 static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
884 {
885 struct max310x_one *one = to_max310x_port(port);
886
887 schedule_work(&one->md_work);
888 }
889
890 static void max310x_break_ctl(struct uart_port *port, int break_state)
891 {
892 max310x_port_update(port, MAX310X_LCR_REG,
893 MAX310X_LCR_TXBREAK_BIT,
894 break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
895 }
896
897 static void max310x_set_termios(struct uart_port *port,
898 struct ktermios *termios,
899 struct ktermios *old)
900 {
901 unsigned int lcr = 0, flow = 0;
902 int baud;
903
904 /* Mask termios capabilities we don't support */
905 termios->c_cflag &= ~CMSPAR;
906
907 /* Word size */
908 switch (termios->c_cflag & CSIZE) {
909 case CS5:
910 break;
911 case CS6:
912 lcr = MAX310X_LCR_LENGTH0_BIT;
913 break;
914 case CS7:
915 lcr = MAX310X_LCR_LENGTH1_BIT;
916 break;
917 case CS8:
918 default:
919 lcr = MAX310X_LCR_LENGTH1_BIT | MAX310X_LCR_LENGTH0_BIT;
920 break;
921 }
922
923 /* Parity */
924 if (termios->c_cflag & PARENB) {
925 lcr |= MAX310X_LCR_PARITY_BIT;
926 if (!(termios->c_cflag & PARODD))
927 lcr |= MAX310X_LCR_EVENPARITY_BIT;
928 }
929
930 /* Stop bits */
931 if (termios->c_cflag & CSTOPB)
932 lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
933
934 /* Update LCR register */
935 max310x_port_write(port, MAX310X_LCR_REG, lcr);
936
937 /* Set read status mask */
938 port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
939 if (termios->c_iflag & INPCK)
940 port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
941 MAX310X_LSR_FRERR_BIT;
942 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
943 port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
944
945 /* Set status ignore mask */
946 port->ignore_status_mask = 0;
947 if (termios->c_iflag & IGNBRK)
948 port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
949 if (!(termios->c_cflag & CREAD))
950 port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
951 MAX310X_LSR_RXOVR_BIT |
952 MAX310X_LSR_FRERR_BIT |
953 MAX310X_LSR_RXBRK_BIT;
954
955 /* Configure flow control */
956 max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
957 max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
958
959 /* Disable transmitter before enabling AutoCTS or auto transmitter
960 * flow control
961 */
962 if (termios->c_cflag & CRTSCTS || termios->c_iflag & IXOFF) {
963 max310x_port_update(port, MAX310X_MODE1_REG,
964 MAX310X_MODE1_TXDIS_BIT,
965 MAX310X_MODE1_TXDIS_BIT);
966 }
967
968 port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
969
970 if (termios->c_cflag & CRTSCTS) {
971 /* Enable AUTORTS and AUTOCTS */
972 port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
973 flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
974 MAX310X_FLOWCTRL_AUTORTS_BIT;
975 }
976 if (termios->c_iflag & IXON)
977 flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
978 MAX310X_FLOWCTRL_SWFLOWEN_BIT;
979 if (termios->c_iflag & IXOFF) {
980 port->status |= UPSTAT_AUTOXOFF;
981 flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
982 MAX310X_FLOWCTRL_SWFLOWEN_BIT;
983 }
984 max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
985
986 /* Enable transmitter after disabling AutoCTS and auto transmitter
987 * flow control
988 */
989 if (!(termios->c_cflag & CRTSCTS) && !(termios->c_iflag & IXOFF)) {
990 max310x_port_update(port, MAX310X_MODE1_REG,
991 MAX310X_MODE1_TXDIS_BIT,
992 0);
993 }
994
995 /* Get baud rate generator configuration */
996 baud = uart_get_baud_rate(port, termios, old,
997 port->uartclk / 16 / 0xffff,
998 port->uartclk / 4);
999
1000 /* Setup baudrate generator */
1001 baud = max310x_set_baud(port, baud);
1002
1003 /* Update timeout according to new baud rate */
1004 uart_update_timeout(port, termios->c_cflag, baud);
1005 }
1006
1007 static void max310x_rs_proc(struct work_struct *ws)
1008 {
1009 struct max310x_one *one = container_of(ws, struct max310x_one, rs_work);
1010 unsigned int delay, mode1 = 0, mode2 = 0;
1011
1012 delay = (one->port.rs485.delay_rts_before_send << 4) |
1013 one->port.rs485.delay_rts_after_send;
1014 max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, delay);
1015
1016 if (one->port.rs485.flags & SER_RS485_ENABLED) {
1017 mode1 = MAX310X_MODE1_TRNSCVCTRL_BIT;
1018
1019 if (!(one->port.rs485.flags & SER_RS485_RX_DURING_TX))
1020 mode2 = MAX310X_MODE2_ECHOSUPR_BIT;
1021 }
1022
1023 max310x_port_update(&one->port, MAX310X_MODE1_REG,
1024 MAX310X_MODE1_TRNSCVCTRL_BIT, mode1);
1025 max310x_port_update(&one->port, MAX310X_MODE2_REG,
1026 MAX310X_MODE2_ECHOSUPR_BIT, mode2);
1027 }
1028
1029 static int max310x_rs485_config(struct uart_port *port,
1030 struct serial_rs485 *rs485)
1031 {
1032 struct max310x_one *one = to_max310x_port(port);
1033
1034 if ((rs485->delay_rts_before_send > 0x0f) ||
1035 (rs485->delay_rts_after_send > 0x0f))
1036 return -ERANGE;
1037
1038 rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX |
1039 SER_RS485_ENABLED;
1040 memset(rs485->padding, 0, sizeof(rs485->padding));
1041 port->rs485 = *rs485;
1042
1043 schedule_work(&one->rs_work);
1044
1045 return 0;
1046 }
1047
1048 static int max310x_startup(struct uart_port *port)
1049 {
1050 struct max310x_port *s = dev_get_drvdata(port->dev);
1051 unsigned int val;
1052
1053 s->devtype->power(port, 1);
1054
1055 /* Configure MODE1 register */
1056 max310x_port_update(port, MAX310X_MODE1_REG,
1057 MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
1058
1059 /* Reset FIFOs */
1060 max310x_port_write(port, MAX310X_MODE2_REG,
1061 MAX310X_MODE2_FIFORST_BIT);
1062 max310x_port_update(port, MAX310X_MODE2_REG,
1063 MAX310X_MODE2_FIFORST_BIT, 0);
1064
1065 /* Configure mode1/mode2 to have rs485/rs232 enabled at startup */
1066 val = (clamp(port->rs485.delay_rts_before_send, 0U, 15U) << 4) |
1067 clamp(port->rs485.delay_rts_after_send, 0U, 15U);
1068 max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val);
1069
1070 if (port->rs485.flags & SER_RS485_ENABLED) {
1071 max310x_port_update(port, MAX310X_MODE1_REG,
1072 MAX310X_MODE1_TRNSCVCTRL_BIT,
1073 MAX310X_MODE1_TRNSCVCTRL_BIT);
1074
1075 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
1076 max310x_port_update(port, MAX310X_MODE2_REG,
1077 MAX310X_MODE2_ECHOSUPR_BIT,
1078 MAX310X_MODE2_ECHOSUPR_BIT);
1079 }
1080
1081 /* Configure flow control levels */
1082 /* Flow control halt level 96, resume level 48 */
1083 max310x_port_write(port, MAX310X_FLOWLVL_REG,
1084 MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
1085
1086 /* Clear IRQ status register */
1087 max310x_port_read(port, MAX310X_IRQSTS_REG);
1088
1089 /*
1090 * Let's ask for an interrupt after a timeout equivalent to
1091 * the receiving time of 4 characters after the last character
1092 * has been received.
1093 */
1094 max310x_port_write(port, MAX310X_RXTO_REG, 4);
1095
1096 /*
1097 * Make sure we also get RX interrupts when the RX FIFO is
1098 * filling up quickly, so get an interrupt when half of the RX
1099 * FIFO has been filled in.
1100 */
1101 max310x_port_write(port, MAX310X_FIFOTRIGLVL_REG,
1102 MAX310X_FIFOTRIGLVL_RX(MAX310X_FIFO_SIZE / 2));
1103
1104 /* Enable RX timeout interrupt in LSR */
1105 max310x_port_write(port, MAX310X_LSR_IRQEN_REG,
1106 MAX310X_LSR_RXTO_BIT);
1107
1108 /* Enable LSR, RX FIFO trigger, CTS change interrupts */
1109 val = MAX310X_IRQ_LSR_BIT | MAX310X_IRQ_RXFIFO_BIT | MAX310X_IRQ_TXEMPTY_BIT;
1110 max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
1111
1112 return 0;
1113 }
1114
1115 static void max310x_shutdown(struct uart_port *port)
1116 {
1117 struct max310x_port *s = dev_get_drvdata(port->dev);
1118
1119 /* Disable all interrupts */
1120 max310x_port_write(port, MAX310X_IRQEN_REG, 0);
1121
1122 s->devtype->power(port, 0);
1123 }
1124
1125 static const char *max310x_type(struct uart_port *port)
1126 {
1127 struct max310x_port *s = dev_get_drvdata(port->dev);
1128
1129 return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
1130 }
1131
1132 static int max310x_request_port(struct uart_port *port)
1133 {
1134 /* Do nothing */
1135 return 0;
1136 }
1137
1138 static void max310x_config_port(struct uart_port *port, int flags)
1139 {
1140 if (flags & UART_CONFIG_TYPE)
1141 port->type = PORT_MAX310X;
1142 }
1143
1144 static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
1145 {
1146 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
1147 return -EINVAL;
1148 if (s->irq != port->irq)
1149 return -EINVAL;
1150
1151 return 0;
1152 }
1153
1154 static void max310x_null_void(struct uart_port *port)
1155 {
1156 /* Do nothing */
1157 }
1158
1159 static const struct uart_ops max310x_ops = {
1160 .tx_empty = max310x_tx_empty,
1161 .set_mctrl = max310x_set_mctrl,
1162 .get_mctrl = max310x_get_mctrl,
1163 .stop_tx = max310x_null_void,
1164 .start_tx = max310x_start_tx,
1165 .stop_rx = max310x_null_void,
1166 .break_ctl = max310x_break_ctl,
1167 .startup = max310x_startup,
1168 .shutdown = max310x_shutdown,
1169 .set_termios = max310x_set_termios,
1170 .type = max310x_type,
1171 .request_port = max310x_request_port,
1172 .release_port = max310x_null_void,
1173 .config_port = max310x_config_port,
1174 .verify_port = max310x_verify_port,
1175 };
1176
1177 static int __maybe_unused max310x_suspend(struct device *dev)
1178 {
1179 struct max310x_port *s = dev_get_drvdata(dev);
1180 int i;
1181
1182 for (i = 0; i < s->devtype->nr; i++) {
1183 uart_suspend_port(&max310x_uart, &s->p[i].port);
1184 s->devtype->power(&s->p[i].port, 0);
1185 }
1186
1187 return 0;
1188 }
1189
1190 static int __maybe_unused max310x_resume(struct device *dev)
1191 {
1192 struct max310x_port *s = dev_get_drvdata(dev);
1193 int i;
1194
1195 for (i = 0; i < s->devtype->nr; i++) {
1196 s->devtype->power(&s->p[i].port, 1);
1197 uart_resume_port(&max310x_uart, &s->p[i].port);
1198 }
1199
1200 return 0;
1201 }
1202
1203 static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
1204
1205 #ifdef CONFIG_GPIOLIB
1206 static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset)
1207 {
1208 unsigned int val;
1209 struct max310x_port *s = gpiochip_get_data(chip);
1210 struct uart_port *port = &s->p[offset / 4].port;
1211
1212 val = max310x_port_read(port, MAX310X_GPIODATA_REG);
1213
1214 return !!((val >> 4) & (1 << (offset % 4)));
1215 }
1216
1217 static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
1218 {
1219 struct max310x_port *s = gpiochip_get_data(chip);
1220 struct uart_port *port = &s->p[offset / 4].port;
1221
1222 max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1223 value ? 1 << (offset % 4) : 0);
1224 }
1225
1226 static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
1227 {
1228 struct max310x_port *s = gpiochip_get_data(chip);
1229 struct uart_port *port = &s->p[offset / 4].port;
1230
1231 max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
1232
1233 return 0;
1234 }
1235
1236 static int max310x_gpio_direction_output(struct gpio_chip *chip,
1237 unsigned offset, int value)
1238 {
1239 struct max310x_port *s = gpiochip_get_data(chip);
1240 struct uart_port *port = &s->p[offset / 4].port;
1241
1242 max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1243 value ? 1 << (offset % 4) : 0);
1244 max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
1245 1 << (offset % 4));
1246
1247 return 0;
1248 }
1249
1250 static int max310x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
1251 unsigned long config)
1252 {
1253 struct max310x_port *s = gpiochip_get_data(chip);
1254 struct uart_port *port = &s->p[offset / 4].port;
1255
1256 switch (pinconf_to_config_param(config)) {
1257 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
1258 max310x_port_update(port, MAX310X_GPIOCFG_REG,
1259 1 << ((offset % 4) + 4),
1260 1 << ((offset % 4) + 4));
1261 return 0;
1262 case PIN_CONFIG_DRIVE_PUSH_PULL:
1263 max310x_port_update(port, MAX310X_GPIOCFG_REG,
1264 1 << ((offset % 4) + 4), 0);
1265 return 0;
1266 default:
1267 return -ENOTSUPP;
1268 }
1269 }
1270 #endif
1271
1272 static int max310x_probe(struct device *dev, const struct max310x_devtype *devtype,
1273 struct regmap *regmap, int irq)
1274 {
1275 int i, ret, fmin, fmax, freq, uartclk;
1276 struct max310x_port *s;
1277 bool xtal = false;
1278
1279 if (IS_ERR(regmap))
1280 return PTR_ERR(regmap);
1281
1282 /* Alloc port structure */
1283 s = devm_kzalloc(dev, struct_size(s, p, devtype->nr), GFP_KERNEL);
1284 if (!s) {
1285 dev_err(dev, "Error allocating port structure\n");
1286 return -ENOMEM;
1287 }
1288
1289 s->clk = devm_clk_get_optional(dev, "osc");
1290 if (IS_ERR(s->clk))
1291 return PTR_ERR(s->clk);
1292 if (s->clk) {
1293 fmin = 500000;
1294 fmax = 35000000;
1295 } else {
1296 s->clk = devm_clk_get_optional(dev, "xtal");
1297 if (IS_ERR(s->clk))
1298 return PTR_ERR(s->clk);
1299 if (s->clk) {
1300 fmin = 1000000;
1301 fmax = 4000000;
1302 xtal = true;
1303 } else {
1304 dev_err(dev, "Cannot get clock\n");
1305 return -EINVAL;
1306 }
1307 }
1308
1309 ret = clk_prepare_enable(s->clk);
1310 if (ret)
1311 return ret;
1312
1313 freq = clk_get_rate(s->clk);
1314 /* Check frequency limits */
1315 if (freq < fmin || freq > fmax) {
1316 ret = -ERANGE;
1317 goto out_clk;
1318 }
1319
1320 s->regmap = regmap;
1321 s->devtype = devtype;
1322 dev_set_drvdata(dev, s);
1323
1324 /* Check device to ensure we are talking to what we expect */
1325 ret = devtype->detect(dev);
1326 if (ret)
1327 goto out_clk;
1328
1329 for (i = 0; i < devtype->nr; i++) {
1330 unsigned int offs = i << 5;
1331
1332 /* Reset port */
1333 regmap_write(s->regmap, MAX310X_MODE2_REG + offs,
1334 MAX310X_MODE2_RST_BIT);
1335 /* Clear port reset */
1336 regmap_write(s->regmap, MAX310X_MODE2_REG + offs, 0);
1337
1338 /* Wait for port startup */
1339 do {
1340 regmap_read(s->regmap,
1341 MAX310X_BRGDIVLSB_REG + offs, &ret);
1342 } while (ret != 0x01);
1343
1344 regmap_write(s->regmap, MAX310X_MODE1_REG + offs,
1345 devtype->mode1);
1346 }
1347
1348 uartclk = max310x_set_ref_clk(dev, s, freq, xtal);
1349 dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
1350
1351 for (i = 0; i < devtype->nr; i++) {
1352 unsigned int line;
1353
1354 line = find_first_zero_bit(max310x_lines, MAX310X_UART_NRMAX);
1355 if (line == MAX310X_UART_NRMAX) {
1356 ret = -ERANGE;
1357 goto out_uart;
1358 }
1359
1360 /* Initialize port data */
1361 s->p[i].port.line = line;
1362 s->p[i].port.dev = dev;
1363 s->p[i].port.irq = irq;
1364 s->p[i].port.type = PORT_MAX310X;
1365 s->p[i].port.fifosize = MAX310X_FIFO_SIZE;
1366 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1367 s->p[i].port.iotype = UPIO_PORT;
1368 s->p[i].port.iobase = i * 0x20;
1369 s->p[i].port.membase = (void __iomem *)~0;
1370 s->p[i].port.uartclk = uartclk;
1371 s->p[i].port.rs485_config = max310x_rs485_config;
1372 s->p[i].port.ops = &max310x_ops;
1373 /* Disable all interrupts */
1374 max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
1375 /* Clear IRQ status register */
1376 max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
1377 /* Initialize queue for start TX */
1378 INIT_WORK(&s->p[i].tx_work, max310x_tx_proc);
1379 /* Initialize queue for changing LOOPBACK mode */
1380 INIT_WORK(&s->p[i].md_work, max310x_md_proc);
1381 /* Initialize queue for changing RS485 mode */
1382 INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
1383 /* Initialize SPI-transfer buffers */
1384 s->p[i].wr_header = (s->p[i].port.iobase + MAX310X_THR_REG) |
1385 MAX310X_WRITE_BIT;
1386 s->p[i].rd_header = (s->p[i].port.iobase + MAX310X_RHR_REG);
1387
1388 /* Register port */
1389 ret = uart_add_one_port(&max310x_uart, &s->p[i].port);
1390 if (ret) {
1391 s->p[i].port.dev = NULL;
1392 goto out_uart;
1393 }
1394 set_bit(line, max310x_lines);
1395
1396 /* Go to suspend mode */
1397 devtype->power(&s->p[i].port, 0);
1398 }
1399
1400 #ifdef CONFIG_GPIOLIB
1401 /* Setup GPIO cotroller */
1402 s->gpio.owner = THIS_MODULE;
1403 s->gpio.parent = dev;
1404 s->gpio.label = devtype->name;
1405 s->gpio.direction_input = max310x_gpio_direction_input;
1406 s->gpio.get = max310x_gpio_get;
1407 s->gpio.direction_output= max310x_gpio_direction_output;
1408 s->gpio.set = max310x_gpio_set;
1409 s->gpio.set_config = max310x_gpio_set_config;
1410 s->gpio.base = -1;
1411 s->gpio.ngpio = devtype->nr * 4;
1412 s->gpio.can_sleep = 1;
1413 ret = devm_gpiochip_add_data(dev, &s->gpio, s);
1414 if (ret)
1415 goto out_uart;
1416 #endif
1417
1418 /* Setup interrupt */
1419 ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
1420 IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), s);
1421 if (!ret)
1422 return 0;
1423
1424 dev_err(dev, "Unable to reguest IRQ %i\n", irq);
1425
1426 out_uart:
1427 for (i = 0; i < devtype->nr; i++) {
1428 if (s->p[i].port.dev) {
1429 uart_remove_one_port(&max310x_uart, &s->p[i].port);
1430 clear_bit(s->p[i].port.line, max310x_lines);
1431 }
1432 }
1433
1434 out_clk:
1435 clk_disable_unprepare(s->clk);
1436
1437 return ret;
1438 }
1439
1440 static int max310x_remove(struct device *dev)
1441 {
1442 struct max310x_port *s = dev_get_drvdata(dev);
1443 int i;
1444
1445 for (i = 0; i < s->devtype->nr; i++) {
1446 cancel_work_sync(&s->p[i].tx_work);
1447 cancel_work_sync(&s->p[i].md_work);
1448 cancel_work_sync(&s->p[i].rs_work);
1449 uart_remove_one_port(&max310x_uart, &s->p[i].port);
1450 clear_bit(s->p[i].port.line, max310x_lines);
1451 s->devtype->power(&s->p[i].port, 0);
1452 }
1453
1454 clk_disable_unprepare(s->clk);
1455
1456 return 0;
1457 }
1458
1459 static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
1460 { .compatible = "maxim,max3107", .data = &max3107_devtype, },
1461 { .compatible = "maxim,max3108", .data = &max3108_devtype, },
1462 { .compatible = "maxim,max3109", .data = &max3109_devtype, },
1463 { .compatible = "maxim,max14830", .data = &max14830_devtype },
1464 { }
1465 };
1466 MODULE_DEVICE_TABLE(of, max310x_dt_ids);
1467
1468 static struct regmap_config regcfg = {
1469 .reg_bits = 8,
1470 .val_bits = 8,
1471 .write_flag_mask = MAX310X_WRITE_BIT,
1472 .cache_type = REGCACHE_RBTREE,
1473 .writeable_reg = max310x_reg_writeable,
1474 .volatile_reg = max310x_reg_volatile,
1475 .precious_reg = max310x_reg_precious,
1476 };
1477
1478 #ifdef CONFIG_SPI_MASTER
1479 static int max310x_spi_probe(struct spi_device *spi)
1480 {
1481 const struct max310x_devtype *devtype;
1482 struct regmap *regmap;
1483 int ret;
1484
1485 /* Setup SPI bus */
1486 spi->bits_per_word = 8;
1487 spi->mode = spi->mode ? : SPI_MODE_0;
1488 spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
1489 ret = spi_setup(spi);
1490 if (ret)
1491 return ret;
1492
1493 devtype = device_get_match_data(&spi->dev);
1494 if (!devtype)
1495 devtype = (struct max310x_devtype *)spi_get_device_id(spi)->driver_data;
1496
1497 regcfg.max_register = devtype->nr * 0x20 - 1;
1498 regmap = devm_regmap_init_spi(spi, &regcfg);
1499
1500 return max310x_probe(&spi->dev, devtype, regmap, spi->irq);
1501 }
1502
1503 static int max310x_spi_remove(struct spi_device *spi)
1504 {
1505 return max310x_remove(&spi->dev);
1506 }
1507
1508 static const struct spi_device_id max310x_id_table[] = {
1509 { "max3107", (kernel_ulong_t)&max3107_devtype, },
1510 { "max3108", (kernel_ulong_t)&max3108_devtype, },
1511 { "max3109", (kernel_ulong_t)&max3109_devtype, },
1512 { "max14830", (kernel_ulong_t)&max14830_devtype, },
1513 { }
1514 };
1515 MODULE_DEVICE_TABLE(spi, max310x_id_table);
1516
1517 static struct spi_driver max310x_spi_driver = {
1518 .driver = {
1519 .name = MAX310X_NAME,
1520 .of_match_table = max310x_dt_ids,
1521 .pm = &max310x_pm_ops,
1522 },
1523 .probe = max310x_spi_probe,
1524 .remove = max310x_spi_remove,
1525 .id_table = max310x_id_table,
1526 };
1527 #endif
1528
1529 static int __init max310x_uart_init(void)
1530 {
1531 int ret;
1532
1533 bitmap_zero(max310x_lines, MAX310X_UART_NRMAX);
1534
1535 ret = uart_register_driver(&max310x_uart);
1536 if (ret)
1537 return ret;
1538
1539 #ifdef CONFIG_SPI_MASTER
1540 ret = spi_register_driver(&max310x_spi_driver);
1541 #endif
1542
1543 return ret;
1544 }
1545 module_init(max310x_uart_init);
1546
1547 static void __exit max310x_uart_exit(void)
1548 {
1549 #ifdef CONFIG_SPI_MASTER
1550 spi_unregister_driver(&max310x_spi_driver);
1551 #endif
1552
1553 uart_unregister_driver(&max310x_uart);
1554 }
1555 module_exit(max310x_uart_exit);
1556
1557 MODULE_LICENSE("GPL");
1558 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1559 MODULE_DESCRIPTION("MAX310X serial driver");
Linux with added FPC-III support