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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / drivers / leds / leds-pca955x.c
blob78183f90820eac0e424315ba75302dac62a48ca7
1 /*
2 * Copyright 2007-2008 Extreme Engineering Solutions, Inc.
3 *
4 * Author: Nate Case <ncase@xes-inc.com>
5 *
6 * This file is subject to the terms and conditions of version 2 of
7 * the GNU General Public License. See the file COPYING in the main
8 * directory of this archive for more details.
9 *
10 * LED driver for various PCA955x I2C LED drivers
11 *
12 * Supported devices:
13 *
14 * Device Description 7-bit slave address
15 * ------ ----------- -------------------
16 * PCA9550 2-bit driver 0x60 .. 0x61
17 * PCA9551 8-bit driver 0x60 .. 0x67
18 * PCA9552 16-bit driver 0x60 .. 0x67
19 * PCA9553/01 4-bit driver 0x62
20 * PCA9553/02 4-bit driver 0x63
21 *
22 * Philips PCA955x LED driver chips follow a register map as shown below:
23 *
24 * Control Register Description
25 * ---------------- -----------
26 * 0x0 Input register 0
27 * ..
28 * NUM_INPUT_REGS - 1 Last Input register X
29 *
30 * NUM_INPUT_REGS Frequency prescaler 0
31 * NUM_INPUT_REGS + 1 PWM register 0
32 * NUM_INPUT_REGS + 2 Frequency prescaler 1
33 * NUM_INPUT_REGS + 3 PWM register 1
34 *
35 * NUM_INPUT_REGS + 4 LED selector 0
36 * NUM_INPUT_REGS + 4
37 * + NUM_LED_REGS - 1 Last LED selector
38 *
39 * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
40 * bits the chip supports.
41 */
42
43 #include <linux/acpi.h>
44 #include <linux/ctype.h>
45 #include <linux/delay.h>
46 #include <linux/err.h>
47 #include <linux/gpio.h>
48 #include <linux/i2c.h>
49 #include <linux/leds.h>
50 #include <linux/module.h>
51 #include <linux/of_device.h>
52 #include <linux/of.h>
53 #include <linux/slab.h>
54 #include <linux/string.h>
55
56 #include <dt-bindings/leds/leds-pca955x.h>
57
58 /* LED select registers determine the source that drives LED outputs */
59 #define PCA955X_LS_LED_ON 0x0 /* Output LOW */
60 #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
61 #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
62 #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
63
64 #define PCA955X_GPIO_INPUT LED_OFF
65 #define PCA955X_GPIO_HIGH LED_OFF
66 #define PCA955X_GPIO_LOW LED_FULL
67
68 enum pca955x_type {
69 pca9550,
70 pca9551,
71 pca9552,
72 pca9553,
73 };
74
75 struct pca955x_chipdef {
76 int bits;
77 u8 slv_addr; /* 7-bit slave address mask */
78 int slv_addr_shift; /* Number of bits to ignore */
79 };
80
81 static struct pca955x_chipdef pca955x_chipdefs[] = {
82 [pca9550] = {
83 .bits = 2,
84 .slv_addr = /* 110000x */ 0x60,
85 .slv_addr_shift = 1,
86 },
87 [pca9551] = {
88 .bits = 8,
89 .slv_addr = /* 1100xxx */ 0x60,
90 .slv_addr_shift = 3,
91 },
92 [pca9552] = {
93 .bits = 16,
94 .slv_addr = /* 1100xxx */ 0x60,
95 .slv_addr_shift = 3,
96 },
97 [pca9553] = {
98 .bits = 4,
99 .slv_addr = /* 110001x */ 0x62,
100 .slv_addr_shift = 1,
101 },
102 };
103
104 static const struct i2c_device_id pca955x_id[] = {
105 { "pca9550", pca9550 },
106 { "pca9551", pca9551 },
107 { "pca9552", pca9552 },
108 { "pca9553", pca9553 },
109 { }
110 };
111 MODULE_DEVICE_TABLE(i2c, pca955x_id);
112
113 static const struct acpi_device_id pca955x_acpi_ids[] = {
114 { "PCA9550", pca9550 },
115 { "PCA9551", pca9551 },
116 { "PCA9552", pca9552 },
117 { "PCA9553", pca9553 },
118 { }
119 };
120 MODULE_DEVICE_TABLE(acpi, pca955x_acpi_ids);
121
122 struct pca955x {
123 struct mutex lock;
124 struct pca955x_led *leds;
125 struct pca955x_chipdef *chipdef;
126 struct i2c_client *client;
127 #ifdef CONFIG_LEDS_PCA955X_GPIO
128 struct gpio_chip gpio;
129 #endif
130 };
131
132 struct pca955x_led {
133 struct pca955x *pca955x;
134 struct led_classdev led_cdev;
135 int led_num; /* 0 .. 15 potentially */
136 char name[32];
137 u32 type;
138 const char *default_trigger;
139 };
140
141 struct pca955x_platform_data {
142 struct pca955x_led *leds;
143 int num_leds;
144 };
145
146 /* 8 bits per input register */
147 static inline int pca95xx_num_input_regs(int bits)
148 {
149 return (bits + 7) / 8;
150 }
151
152 /* 4 bits per LED selector register */
153 static inline int pca95xx_num_led_regs(int bits)
154 {
155 return (bits + 3) / 4;
156 }
157
158 /*
159 * Return an LED selector register value based on an existing one, with
160 * the appropriate 2-bit state value set for the given LED number (0-3).
161 */
162 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
163 {
164 return (oldval & (~(0x3 << (led_num << 1)))) |
165 ((state & 0x3) << (led_num << 1));
166 }
167
168 /*
169 * Write to frequency prescaler register, used to program the
170 * period of the PWM output. period = (PSCx + 1) / 38
171 */
172 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
173 {
174 struct pca955x *pca955x = i2c_get_clientdata(client);
175 int ret;
176
177 ret = i2c_smbus_write_byte_data(client,
178 pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
179 val);
180 if (ret < 0)
181 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
182 __func__, n, val, ret);
183 return ret;
184 }
185
186 /*
187 * Write to PWM register, which determines the duty cycle of the
188 * output. LED is OFF when the count is less than the value of this
189 * register, and ON when it is greater. If PWMx == 0, LED is always OFF.
190 *
191 * Duty cycle is (256 - PWMx) / 256
192 */
193 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
194 {
195 struct pca955x *pca955x = i2c_get_clientdata(client);
196 int ret;
197
198 ret = i2c_smbus_write_byte_data(client,
199 pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
200 val);
201 if (ret < 0)
202 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
203 __func__, n, val, ret);
204 return ret;
205 }
206
207 /*
208 * Write to LED selector register, which determines the source that
209 * drives the LED output.
210 */
211 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
212 {
213 struct pca955x *pca955x = i2c_get_clientdata(client);
214 int ret;
215
216 ret = i2c_smbus_write_byte_data(client,
217 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
218 val);
219 if (ret < 0)
220 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
221 __func__, n, val, ret);
222 return ret;
223 }
224
225 /*
226 * Read the LED selector register, which determines the source that
227 * drives the LED output.
228 */
229 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
230 {
231 struct pca955x *pca955x = i2c_get_clientdata(client);
232 int ret;
233
234 ret = i2c_smbus_read_byte_data(client,
235 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
236 if (ret < 0) {
237 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
238 __func__, n, ret);
239 return ret;
240 }
241 *val = (u8)ret;
242 return 0;
243 }
244
245 static int pca955x_led_set(struct led_classdev *led_cdev,
246 enum led_brightness value)
247 {
248 struct pca955x_led *pca955x_led;
249 struct pca955x *pca955x;
250 u8 ls;
251 int chip_ls; /* which LSx to use (0-3 potentially) */
252 int ls_led; /* which set of bits within LSx to use (0-3) */
253 int ret;
254
255 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
256 pca955x = pca955x_led->pca955x;
257
258 chip_ls = pca955x_led->led_num / 4;
259 ls_led = pca955x_led->led_num % 4;
260
261 mutex_lock(&pca955x->lock);
262
263 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
264 if (ret)
265 goto out;
266
267 switch (value) {
268 case LED_FULL:
269 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
270 break;
271 case LED_OFF:
272 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
273 break;
274 case LED_HALF:
275 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
276 break;
277 default:
278 /*
279 * Use PWM1 for all other values. This has the unwanted
280 * side effect of making all LEDs on the chip share the
281 * same brightness level if set to a value other than
282 * OFF, HALF, or FULL. But, this is probably better than
283 * just turning off for all other values.
284 */
285 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
286 if (ret)
287 goto out;
288 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
289 break;
290 }
291
292 ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
293
294 out:
295 mutex_unlock(&pca955x->lock);
296
297 return ret;
298 }
299
300 #ifdef CONFIG_LEDS_PCA955X_GPIO
301 /*
302 * Read the INPUT register, which contains the state of LEDs.
303 */
304 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
305 {
306 int ret = i2c_smbus_read_byte_data(client, n);
307
308 if (ret < 0) {
309 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
310 __func__, n, ret);
311 return ret;
312 }
313 *val = (u8)ret;
314 return 0;
315
316 }
317
318 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
319 {
320 struct pca955x *pca955x = gpiochip_get_data(gc);
321 struct pca955x_led *led = &pca955x->leds[offset];
322
323 if (led->type == PCA955X_TYPE_GPIO)
324 return 0;
325
326 return -EBUSY;
327 }
328
329 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
330 int val)
331 {
332 struct pca955x *pca955x = gpiochip_get_data(gc);
333 struct pca955x_led *led = &pca955x->leds[offset];
334
335 if (val)
336 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
337
338 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
339 }
340
341 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
342 int val)
343 {
344 pca955x_set_value(gc, offset, val);
345 }
346
347 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
348 {
349 struct pca955x *pca955x = gpiochip_get_data(gc);
350 struct pca955x_led *led = &pca955x->leds[offset];
351 u8 reg = 0;
352
353 /* There is nothing we can do about errors */
354 pca955x_read_input(pca955x->client, led->led_num / 8, &reg);
355
356 return !!(reg & (1 << (led->led_num % 8)));
357 }
358
359 static int pca955x_gpio_direction_input(struct gpio_chip *gc,
360 unsigned int offset)
361 {
362 struct pca955x *pca955x = gpiochip_get_data(gc);
363 struct pca955x_led *led = &pca955x->leds[offset];
364
365 /* To use as input ensure pin is not driven. */
366 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
367 }
368
369 static int pca955x_gpio_direction_output(struct gpio_chip *gc,
370 unsigned int offset, int val)
371 {
372 return pca955x_set_value(gc, offset, val);
373 }
374 #endif /* CONFIG_LEDS_PCA955X_GPIO */
375
376 #if IS_ENABLED(CONFIG_OF)
377 static struct pca955x_platform_data *
378 pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip)
379 {
380 struct device_node *np = client->dev.of_node;
381 struct device_node *child;
382 struct pca955x_platform_data *pdata;
383 int count;
384
385 count = of_get_child_count(np);
386 if (!count || count > chip->bits)
387 return ERR_PTR(-ENODEV);
388
389 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
390 if (!pdata)
391 return ERR_PTR(-ENOMEM);
392
393 pdata->leds = devm_kzalloc(&client->dev,
394 sizeof(struct pca955x_led) * chip->bits,
395 GFP_KERNEL);
396 if (!pdata->leds)
397 return ERR_PTR(-ENOMEM);
398
399 for_each_child_of_node(np, child) {
400 const char *name;
401 u32 reg;
402 int res;
403
404 res = of_property_read_u32(child, "reg", &reg);
405 if ((res != 0) || (reg >= chip->bits))
406 continue;
407
408 if (of_property_read_string(child, "label", &name))
409 name = child->name;
410
411 snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
412 "%s", name);
413
414 pdata->leds[reg].type = PCA955X_TYPE_LED;
415 of_property_read_u32(child, "type", &pdata->leds[reg].type);
416 of_property_read_string(child, "linux,default-trigger",
417 &pdata->leds[reg].default_trigger);
418 }
419
420 pdata->num_leds = chip->bits;
421
422 return pdata;
423 }
424
425 static const struct of_device_id of_pca955x_match[] = {
426 { .compatible = "nxp,pca9550", .data = (void *)pca9550 },
427 { .compatible = "nxp,pca9551", .data = (void *)pca9551 },
428 { .compatible = "nxp,pca9552", .data = (void *)pca9552 },
429 { .compatible = "nxp,pca9553", .data = (void *)pca9553 },
430 {},
431 };
432
433 MODULE_DEVICE_TABLE(of, of_pca955x_match);
434 #else
435 static struct pca955x_platform_data *
436 pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip)
437 {
438 return ERR_PTR(-ENODEV);
439 }
440 #endif
441
442 static int pca955x_probe(struct i2c_client *client,
443 const struct i2c_device_id *id)
444 {
445 struct pca955x *pca955x;
446 struct pca955x_led *pca955x_led;
447 struct pca955x_chipdef *chip;
448 struct i2c_adapter *adapter;
449 int i, err;
450 struct pca955x_platform_data *pdata;
451 int ngpios = 0;
452
453 if (id) {
454 chip = &pca955x_chipdefs[id->driver_data];
455 } else {
456 const struct acpi_device_id *acpi_id;
457
458 acpi_id = acpi_match_device(pca955x_acpi_ids, &client->dev);
459 if (!acpi_id)
460 return -ENODEV;
461 chip = &pca955x_chipdefs[acpi_id->driver_data];
462 }
463 adapter = to_i2c_adapter(client->dev.parent);
464 pdata = dev_get_platdata(&client->dev);
465 if (!pdata) {
466 pdata = pca955x_pdata_of_init(client, chip);
467 if (IS_ERR(pdata))
468 return PTR_ERR(pdata);
469 }
470
471 /* Make sure the slave address / chip type combo given is possible */
472 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
473 chip->slv_addr) {
474 dev_err(&client->dev, "invalid slave address %02x\n",
475 client->addr);
476 return -ENODEV;
477 }
478
479 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
480 "slave address 0x%02x\n",
481 client->name, chip->bits, client->addr);
482
483 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
484 return -EIO;
485
486 if (pdata->num_leds != chip->bits) {
487 dev_err(&client->dev,
488 "board info claims %d LEDs on a %d-bit chip\n",
489 pdata->num_leds, chip->bits);
490 return -ENODEV;
491 }
492
493 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
494 if (!pca955x)
495 return -ENOMEM;
496
497 pca955x->leds = devm_kzalloc(&client->dev,
498 sizeof(*pca955x_led) * chip->bits, GFP_KERNEL);
499 if (!pca955x->leds)
500 return -ENOMEM;
501
502 i2c_set_clientdata(client, pca955x);
503
504 mutex_init(&pca955x->lock);
505 pca955x->client = client;
506 pca955x->chipdef = chip;
507
508 for (i = 0; i < chip->bits; i++) {
509 pca955x_led = &pca955x->leds[i];
510 pca955x_led->led_num = i;
511 pca955x_led->pca955x = pca955x;
512 pca955x_led->type = pdata->leds[i].type;
513
514 switch (pca955x_led->type) {
515 case PCA955X_TYPE_NONE:
516 break;
517 case PCA955X_TYPE_GPIO:
518 ngpios++;
519 break;
520 case PCA955X_TYPE_LED:
521 /*
522 * Platform data can specify LED names and
523 * default triggers
524 */
525 if (pdata->leds[i].name[0] == '\0')
526 snprintf(pdata->leds[i].name,
527 sizeof(pdata->leds[i].name), "%d", i);
528
529 snprintf(pca955x_led->name,
530 sizeof(pca955x_led->name), "pca955x:%s",
531 pdata->leds[i].name);
532
533 if (pdata->leds[i].default_trigger)
534 pca955x_led->led_cdev.default_trigger =
535 pdata->leds[i].default_trigger;
536
537 pca955x_led->led_cdev.name = pca955x_led->name;
538 pca955x_led->led_cdev.brightness_set_blocking =
539 pca955x_led_set;
540
541 err = devm_led_classdev_register(&client->dev,
542 &pca955x_led->led_cdev);
543 if (err)
544 return err;
545
546 /* Turn off LED */
547 err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
548 if (err)
549 return err;
550 }
551 }
552
553 /* PWM0 is used for half brightness or 50% duty cycle */
554 err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
555 if (err)
556 return err;
557
558 /* PWM1 is used for variable brightness, default to OFF */
559 err = pca955x_write_pwm(client, 1, 0);
560 if (err)
561 return err;
562
563 /* Set to fast frequency so we do not see flashing */
564 err = pca955x_write_psc(client, 0, 0);
565 if (err)
566 return err;
567 err = pca955x_write_psc(client, 1, 0);
568 if (err)
569 return err;
570
571 #ifdef CONFIG_LEDS_PCA955X_GPIO
572 if (ngpios) {
573 pca955x->gpio.label = "gpio-pca955x";
574 pca955x->gpio.direction_input = pca955x_gpio_direction_input;
575 pca955x->gpio.direction_output = pca955x_gpio_direction_output;
576 pca955x->gpio.set = pca955x_gpio_set_value;
577 pca955x->gpio.get = pca955x_gpio_get_value;
578 pca955x->gpio.request = pca955x_gpio_request_pin;
579 pca955x->gpio.can_sleep = 1;
580 pca955x->gpio.base = -1;
581 pca955x->gpio.ngpio = ngpios;
582 pca955x->gpio.parent = &client->dev;
583 pca955x->gpio.owner = THIS_MODULE;
584
585 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
586 pca955x);
587 if (err) {
588 /* Use data->gpio.dev as a flag for freeing gpiochip */
589 pca955x->gpio.parent = NULL;
590 dev_warn(&client->dev, "could not add gpiochip\n");
591 return err;
592 }
593 dev_info(&client->dev, "gpios %i...%i\n",
594 pca955x->gpio.base, pca955x->gpio.base +
595 pca955x->gpio.ngpio - 1);
596 }
597 #endif
598
599 return 0;
600 }
601
602 static struct i2c_driver pca955x_driver = {
603 .driver = {
604 .name = "leds-pca955x",
605 .acpi_match_table = ACPI_PTR(pca955x_acpi_ids),
606 .of_match_table = of_match_ptr(of_pca955x_match),
607 },
608 .probe = pca955x_probe,
609 .id_table = pca955x_id,
610 };
611
612 module_i2c_driver(pca955x_driver);
613
614 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
615 MODULE_DESCRIPTION("PCA955x LED driver");
616 MODULE_LICENSE("GPL v2");
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