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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / leds / leds-pca955x.c
blob7087ca4592fc964989cc1bf440bdb4fe9faf30e5
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2007-2008 Extreme Engineering Solutions, Inc.
4 *
5 * Author: Nate Case <ncase@xes-inc.com>
6 *
7 * LED driver for various PCA955x I2C LED drivers
8 *
9 * Supported devices:
10 *
11 * Device Description 7-bit slave address
12 * ------ ----------- -------------------
13 * PCA9550 2-bit driver 0x60 .. 0x61
14 * PCA9551 8-bit driver 0x60 .. 0x67
15 * PCA9552 16-bit driver 0x60 .. 0x67
16 * PCA9553/01 4-bit driver 0x62
17 * PCA9553/02 4-bit driver 0x63
18 *
19 * Philips PCA955x LED driver chips follow a register map as shown below:
20 *
21 * Control Register Description
22 * ---------------- -----------
23 * 0x0 Input register 0
24 * ..
25 * NUM_INPUT_REGS - 1 Last Input register X
26 *
27 * NUM_INPUT_REGS Frequency prescaler 0
28 * NUM_INPUT_REGS + 1 PWM register 0
29 * NUM_INPUT_REGS + 2 Frequency prescaler 1
30 * NUM_INPUT_REGS + 3 PWM register 1
31 *
32 * NUM_INPUT_REGS + 4 LED selector 0
33 * NUM_INPUT_REGS + 4
34 * + NUM_LED_REGS - 1 Last LED selector
35 *
36 * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
37 * bits the chip supports.
38 */
39
40 #include <linux/ctype.h>
41 #include <linux/delay.h>
42 #include <linux/err.h>
43 #include <linux/gpio/driver.h>
44 #include <linux/i2c.h>
45 #include <linux/leds.h>
46 #include <linux/module.h>
47 #include <linux/of.h>
48 #include <linux/property.h>
49 #include <linux/slab.h>
50 #include <linux/string.h>
51
52 #include <dt-bindings/leds/leds-pca955x.h>
53
54 /* LED select registers determine the source that drives LED outputs */
55 #define PCA955X_LS_LED_ON 0x0 /* Output LOW */
56 #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
57 #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
58 #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
59
60 #define PCA955X_GPIO_INPUT LED_OFF
61 #define PCA955X_GPIO_HIGH LED_OFF
62 #define PCA955X_GPIO_LOW LED_FULL
63
64 enum pca955x_type {
65 pca9550,
66 pca9551,
67 pca9552,
68 ibm_pca9552,
69 pca9553,
70 };
71
72 struct pca955x_chipdef {
73 int bits;
74 u8 slv_addr; /* 7-bit slave address mask */
75 int slv_addr_shift; /* Number of bits to ignore */
76 };
77
78 static struct pca955x_chipdef pca955x_chipdefs[] = {
79 [pca9550] = {
80 .bits = 2,
81 .slv_addr = /* 110000x */ 0x60,
82 .slv_addr_shift = 1,
83 },
84 [pca9551] = {
85 .bits = 8,
86 .slv_addr = /* 1100xxx */ 0x60,
87 .slv_addr_shift = 3,
88 },
89 [pca9552] = {
90 .bits = 16,
91 .slv_addr = /* 1100xxx */ 0x60,
92 .slv_addr_shift = 3,
93 },
94 [ibm_pca9552] = {
95 .bits = 16,
96 .slv_addr = /* 0110xxx */ 0x30,
97 .slv_addr_shift = 3,
98 },
99 [pca9553] = {
100 .bits = 4,
101 .slv_addr = /* 110001x */ 0x62,
102 .slv_addr_shift = 1,
103 },
104 };
105
106 static const struct i2c_device_id pca955x_id[] = {
107 { "pca9550", pca9550 },
108 { "pca9551", pca9551 },
109 { "pca9552", pca9552 },
110 { "ibm-pca9552", ibm_pca9552 },
111 { "pca9553", pca9553 },
112 { }
113 };
114 MODULE_DEVICE_TABLE(i2c, pca955x_id);
115
116 struct pca955x {
117 struct mutex lock;
118 struct pca955x_led *leds;
119 struct pca955x_chipdef *chipdef;
120 struct i2c_client *client;
121 #ifdef CONFIG_LEDS_PCA955X_GPIO
122 struct gpio_chip gpio;
123 #endif
124 };
125
126 struct pca955x_led {
127 struct pca955x *pca955x;
128 struct led_classdev led_cdev;
129 int led_num; /* 0 .. 15 potentially */
130 char name[32];
131 u32 type;
132 const char *default_trigger;
133 };
134
135 struct pca955x_platform_data {
136 struct pca955x_led *leds;
137 int num_leds;
138 };
139
140 /* 8 bits per input register */
141 static inline int pca95xx_num_input_regs(int bits)
142 {
143 return (bits + 7) / 8;
144 }
145
146 /* 4 bits per LED selector register */
147 static inline int pca95xx_num_led_regs(int bits)
148 {
149 return (bits + 3) / 4;
150 }
151
152 /*
153 * Return an LED selector register value based on an existing one, with
154 * the appropriate 2-bit state value set for the given LED number (0-3).
155 */
156 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
157 {
158 return (oldval & (~(0x3 << (led_num << 1)))) |
159 ((state & 0x3) << (led_num << 1));
160 }
161
162 /*
163 * Write to frequency prescaler register, used to program the
164 * period of the PWM output. period = (PSCx + 1) / 38
165 */
166 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
167 {
168 struct pca955x *pca955x = i2c_get_clientdata(client);
169 int ret;
170
171 ret = i2c_smbus_write_byte_data(client,
172 pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
173 val);
174 if (ret < 0)
175 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
176 __func__, n, val, ret);
177 return ret;
178 }
179
180 /*
181 * Write to PWM register, which determines the duty cycle of the
182 * output. LED is OFF when the count is less than the value of this
183 * register, and ON when it is greater. If PWMx == 0, LED is always OFF.
184 *
185 * Duty cycle is (256 - PWMx) / 256
186 */
187 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
188 {
189 struct pca955x *pca955x = i2c_get_clientdata(client);
190 int ret;
191
192 ret = i2c_smbus_write_byte_data(client,
193 pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
194 val);
195 if (ret < 0)
196 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
197 __func__, n, val, ret);
198 return ret;
199 }
200
201 /*
202 * Write to LED selector register, which determines the source that
203 * drives the LED output.
204 */
205 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
206 {
207 struct pca955x *pca955x = i2c_get_clientdata(client);
208 int ret;
209
210 ret = i2c_smbus_write_byte_data(client,
211 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
212 val);
213 if (ret < 0)
214 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
215 __func__, n, val, ret);
216 return ret;
217 }
218
219 /*
220 * Read the LED selector register, which determines the source that
221 * drives the LED output.
222 */
223 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
224 {
225 struct pca955x *pca955x = i2c_get_clientdata(client);
226 int ret;
227
228 ret = i2c_smbus_read_byte_data(client,
229 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
230 if (ret < 0) {
231 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
232 __func__, n, ret);
233 return ret;
234 }
235 *val = (u8)ret;
236 return 0;
237 }
238
239 static int pca955x_led_set(struct led_classdev *led_cdev,
240 enum led_brightness value)
241 {
242 struct pca955x_led *pca955x_led;
243 struct pca955x *pca955x;
244 u8 ls;
245 int chip_ls; /* which LSx to use (0-3 potentially) */
246 int ls_led; /* which set of bits within LSx to use (0-3) */
247 int ret;
248
249 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
250 pca955x = pca955x_led->pca955x;
251
252 chip_ls = pca955x_led->led_num / 4;
253 ls_led = pca955x_led->led_num % 4;
254
255 mutex_lock(&pca955x->lock);
256
257 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
258 if (ret)
259 goto out;
260
261 switch (value) {
262 case LED_FULL:
263 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
264 break;
265 case LED_OFF:
266 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
267 break;
268 case LED_HALF:
269 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
270 break;
271 default:
272 /*
273 * Use PWM1 for all other values. This has the unwanted
274 * side effect of making all LEDs on the chip share the
275 * same brightness level if set to a value other than
276 * OFF, HALF, or FULL. But, this is probably better than
277 * just turning off for all other values.
278 */
279 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
280 if (ret)
281 goto out;
282 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
283 break;
284 }
285
286 ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
287
288 out:
289 mutex_unlock(&pca955x->lock);
290
291 return ret;
292 }
293
294 #ifdef CONFIG_LEDS_PCA955X_GPIO
295 /*
296 * Read the INPUT register, which contains the state of LEDs.
297 */
298 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
299 {
300 int ret = i2c_smbus_read_byte_data(client, n);
301
302 if (ret < 0) {
303 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
304 __func__, n, ret);
305 return ret;
306 }
307 *val = (u8)ret;
308 return 0;
309
310 }
311
312 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
313 {
314 struct pca955x *pca955x = gpiochip_get_data(gc);
315 struct pca955x_led *led = &pca955x->leds[offset];
316
317 if (led->type == PCA955X_TYPE_GPIO)
318 return 0;
319
320 return -EBUSY;
321 }
322
323 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
324 int val)
325 {
326 struct pca955x *pca955x = gpiochip_get_data(gc);
327 struct pca955x_led *led = &pca955x->leds[offset];
328
329 if (val)
330 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
331
332 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
333 }
334
335 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
336 int val)
337 {
338 pca955x_set_value(gc, offset, val);
339 }
340
341 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
342 {
343 struct pca955x *pca955x = gpiochip_get_data(gc);
344 struct pca955x_led *led = &pca955x->leds[offset];
345 u8 reg = 0;
346
347 /* There is nothing we can do about errors */
348 pca955x_read_input(pca955x->client, led->led_num / 8, &reg);
349
350 return !!(reg & (1 << (led->led_num % 8)));
351 }
352
353 static int pca955x_gpio_direction_input(struct gpio_chip *gc,
354 unsigned int offset)
355 {
356 struct pca955x *pca955x = gpiochip_get_data(gc);
357 struct pca955x_led *led = &pca955x->leds[offset];
358
359 /* To use as input ensure pin is not driven. */
360 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
361 }
362
363 static int pca955x_gpio_direction_output(struct gpio_chip *gc,
364 unsigned int offset, int val)
365 {
366 return pca955x_set_value(gc, offset, val);
367 }
368 #endif /* CONFIG_LEDS_PCA955X_GPIO */
369
370 static struct pca955x_platform_data *
371 pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
372 {
373 struct pca955x_platform_data *pdata;
374 struct fwnode_handle *child;
375 int count;
376
377 count = device_get_child_node_count(&client->dev);
378 if (!count || count > chip->bits)
379 return ERR_PTR(-ENODEV);
380
381 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
382 if (!pdata)
383 return ERR_PTR(-ENOMEM);
384
385 pdata->leds = devm_kcalloc(&client->dev,
386 chip->bits, sizeof(struct pca955x_led),
387 GFP_KERNEL);
388 if (!pdata->leds)
389 return ERR_PTR(-ENOMEM);
390
391 device_for_each_child_node(&client->dev, child) {
392 const char *name;
393 u32 reg;
394 int res;
395
396 res = fwnode_property_read_u32(child, "reg", &reg);
397 if ((res != 0) || (reg >= chip->bits))
398 continue;
399
400 res = fwnode_property_read_string(child, "label", &name);
401 if ((res != 0) && is_of_node(child))
402 name = to_of_node(child)->name;
403
404 snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
405 "%s", name);
406
407 pdata->leds[reg].type = PCA955X_TYPE_LED;
408 fwnode_property_read_u32(child, "type", &pdata->leds[reg].type);
409 fwnode_property_read_string(child, "linux,default-trigger",
410 &pdata->leds[reg].default_trigger);
411 }
412
413 pdata->num_leds = chip->bits;
414
415 return pdata;
416 }
417
418 static const struct of_device_id of_pca955x_match[] = {
419 { .compatible = "nxp,pca9550", .data = (void *)pca9550 },
420 { .compatible = "nxp,pca9551", .data = (void *)pca9551 },
421 { .compatible = "nxp,pca9552", .data = (void *)pca9552 },
422 { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 },
423 { .compatible = "nxp,pca9553", .data = (void *)pca9553 },
424 {},
425 };
426 MODULE_DEVICE_TABLE(of, of_pca955x_match);
427
428 static int pca955x_probe(struct i2c_client *client,
429 const struct i2c_device_id *id)
430 {
431 struct pca955x *pca955x;
432 struct pca955x_led *pca955x_led;
433 struct pca955x_chipdef *chip;
434 struct i2c_adapter *adapter;
435 int i, err;
436 struct pca955x_platform_data *pdata;
437 int ngpios = 0;
438
439 chip = &pca955x_chipdefs[id->driver_data];
440 adapter = client->adapter;
441 pdata = dev_get_platdata(&client->dev);
442 if (!pdata) {
443 pdata = pca955x_get_pdata(client, chip);
444 if (IS_ERR(pdata))
445 return PTR_ERR(pdata);
446 }
447
448 /* Make sure the slave address / chip type combo given is possible */
449 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
450 chip->slv_addr) {
451 dev_err(&client->dev, "invalid slave address %02x\n",
452 client->addr);
453 return -ENODEV;
454 }
455
456 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
457 "slave address 0x%02x\n",
458 client->name, chip->bits, client->addr);
459
460 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
461 return -EIO;
462
463 if (pdata->num_leds != chip->bits) {
464 dev_err(&client->dev,
465 "board info claims %d LEDs on a %d-bit chip\n",
466 pdata->num_leds, chip->bits);
467 return -ENODEV;
468 }
469
470 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
471 if (!pca955x)
472 return -ENOMEM;
473
474 pca955x->leds = devm_kcalloc(&client->dev,
475 chip->bits, sizeof(*pca955x_led), GFP_KERNEL);
476 if (!pca955x->leds)
477 return -ENOMEM;
478
479 i2c_set_clientdata(client, pca955x);
480
481 mutex_init(&pca955x->lock);
482 pca955x->client = client;
483 pca955x->chipdef = chip;
484
485 for (i = 0; i < chip->bits; i++) {
486 pca955x_led = &pca955x->leds[i];
487 pca955x_led->led_num = i;
488 pca955x_led->pca955x = pca955x;
489 pca955x_led->type = pdata->leds[i].type;
490
491 switch (pca955x_led->type) {
492 case PCA955X_TYPE_NONE:
493 break;
494 case PCA955X_TYPE_GPIO:
495 ngpios++;
496 break;
497 case PCA955X_TYPE_LED:
498 /*
499 * Platform data can specify LED names and
500 * default triggers
501 */
502 if (pdata->leds[i].name[0] == '\0')
503 snprintf(pdata->leds[i].name,
504 sizeof(pdata->leds[i].name), "%d", i);
505
506 snprintf(pca955x_led->name,
507 sizeof(pca955x_led->name), "pca955x:%s",
508 pdata->leds[i].name);
509
510 if (pdata->leds[i].default_trigger)
511 pca955x_led->led_cdev.default_trigger =
512 pdata->leds[i].default_trigger;
513
514 pca955x_led->led_cdev.name = pca955x_led->name;
515 pca955x_led->led_cdev.brightness_set_blocking =
516 pca955x_led_set;
517
518 err = devm_led_classdev_register(&client->dev,
519 &pca955x_led->led_cdev);
520 if (err)
521 return err;
522
523 /* Turn off LED */
524 err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
525 if (err)
526 return err;
527 }
528 }
529
530 /* PWM0 is used for half brightness or 50% duty cycle */
531 err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
532 if (err)
533 return err;
534
535 /* PWM1 is used for variable brightness, default to OFF */
536 err = pca955x_write_pwm(client, 1, 0);
537 if (err)
538 return err;
539
540 /* Set to fast frequency so we do not see flashing */
541 err = pca955x_write_psc(client, 0, 0);
542 if (err)
543 return err;
544 err = pca955x_write_psc(client, 1, 0);
545 if (err)
546 return err;
547
548 #ifdef CONFIG_LEDS_PCA955X_GPIO
549 if (ngpios) {
550 pca955x->gpio.label = "gpio-pca955x";
551 pca955x->gpio.direction_input = pca955x_gpio_direction_input;
552 pca955x->gpio.direction_output = pca955x_gpio_direction_output;
553 pca955x->gpio.set = pca955x_gpio_set_value;
554 pca955x->gpio.get = pca955x_gpio_get_value;
555 pca955x->gpio.request = pca955x_gpio_request_pin;
556 pca955x->gpio.can_sleep = 1;
557 pca955x->gpio.base = -1;
558 pca955x->gpio.ngpio = ngpios;
559 pca955x->gpio.parent = &client->dev;
560 pca955x->gpio.owner = THIS_MODULE;
561
562 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
563 pca955x);
564 if (err) {
565 /* Use data->gpio.dev as a flag for freeing gpiochip */
566 pca955x->gpio.parent = NULL;
567 dev_warn(&client->dev, "could not add gpiochip\n");
568 return err;
569 }
570 dev_info(&client->dev, "gpios %i...%i\n",
571 pca955x->gpio.base, pca955x->gpio.base +
572 pca955x->gpio.ngpio - 1);
573 }
574 #endif
575
576 return 0;
577 }
578
579 static struct i2c_driver pca955x_driver = {
580 .driver = {
581 .name = "leds-pca955x",
582 .of_match_table = of_pca955x_match,
583 },
584 .probe = pca955x_probe,
585 .id_table = pca955x_id,
586 };
587
588 module_i2c_driver(pca955x_driver);
589
590 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
591 MODULE_DESCRIPTION("PCA955x LED driver");
592 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support