xref: /openbmc/linux/drivers/leds/leds-pca9532.c (revision 275876e2)
1 /*
2  * pca9532.c - 16-bit Led dimmer
3  *
4  * Copyright (C) 2011 Jan Weitzel
5  * Copyright (C) 2008 Riku Voipio
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; version 2 of the License.
10  *
11  * Datasheet: http://www.nxp.com/documents/data_sheet/PCA9532.pdf
12  *
13  */
14 
15 #include <linux/module.h>
16 #include <linux/i2c.h>
17 #include <linux/slab.h>
18 #include <linux/leds.h>
19 #include <linux/input.h>
20 #include <linux/mutex.h>
21 #include <linux/workqueue.h>
22 #include <linux/leds-pca9532.h>
23 #include <linux/gpio.h>
24 
25 /* m =  num_leds*/
26 #define PCA9532_REG_INPUT(i)	((i) >> 3)
27 #define PCA9532_REG_OFFSET(m)	((m) >> 4)
28 #define PCA9532_REG_PSC(m, i)	(PCA9532_REG_OFFSET(m) + 0x1 + (i) * 2)
29 #define PCA9532_REG_PWM(m, i)	(PCA9532_REG_OFFSET(m) + 0x2 + (i) * 2)
30 #define LED_REG(m, led)		(PCA9532_REG_OFFSET(m) + 0x5 + (led >> 2))
31 #define LED_NUM(led)		(led & 0x3)
32 
33 #define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)
34 
35 struct pca9532_chip_info {
36 	u8	num_leds;
37 };
38 
39 struct pca9532_data {
40 	struct i2c_client *client;
41 	struct pca9532_led leds[16];
42 	struct mutex update_lock;
43 	struct input_dev *idev;
44 	struct work_struct work;
45 #ifdef CONFIG_LEDS_PCA9532_GPIO
46 	struct gpio_chip gpio;
47 #endif
48 	const struct pca9532_chip_info *chip_info;
49 	u8 pwm[2];
50 	u8 psc[2];
51 };
52 
53 static int pca9532_probe(struct i2c_client *client,
54 	const struct i2c_device_id *id);
55 static int pca9532_remove(struct i2c_client *client);
56 
57 enum {
58 	pca9530,
59 	pca9531,
60 	pca9532,
61 	pca9533,
62 };
63 
64 static const struct i2c_device_id pca9532_id[] = {
65 	{ "pca9530", pca9530 },
66 	{ "pca9531", pca9531 },
67 	{ "pca9532", pca9532 },
68 	{ "pca9533", pca9533 },
69 	{ }
70 };
71 
72 MODULE_DEVICE_TABLE(i2c, pca9532_id);
73 
74 static const struct pca9532_chip_info pca9532_chip_info_tbl[] = {
75 	[pca9530] = {
76 		.num_leds = 2,
77 	},
78 	[pca9531] = {
79 		.num_leds = 8,
80 	},
81 	[pca9532] = {
82 		.num_leds = 16,
83 	},
84 	[pca9533] = {
85 		.num_leds = 4,
86 	},
87 };
88 
89 static struct i2c_driver pca9532_driver = {
90 	.driver = {
91 		.name = "leds-pca953x",
92 	},
93 	.probe = pca9532_probe,
94 	.remove = pca9532_remove,
95 	.id_table = pca9532_id,
96 };
97 
98 /* We have two pwm/blinkers, but 16 possible leds to drive. Additionally,
99  * the clever Thecus people are using one pwm to drive the beeper. So,
100  * as a compromise we average one pwm to the values requested by all
101  * leds that are not ON/OFF.
102  * */
103 static int pca9532_calcpwm(struct i2c_client *client, int pwm, int blink,
104 	enum led_brightness value)
105 {
106 	int a = 0, b = 0, i = 0;
107 	struct pca9532_data *data = i2c_get_clientdata(client);
108 	for (i = 0; i < data->chip_info->num_leds; i++) {
109 		if (data->leds[i].type == PCA9532_TYPE_LED &&
110 			data->leds[i].state == PCA9532_PWM0+pwm) {
111 				a++;
112 				b += data->leds[i].ldev.brightness;
113 		}
114 	}
115 	if (a == 0) {
116 		dev_err(&client->dev,
117 		"fear of division by zero %d/%d, wanted %d\n",
118 			b, a, value);
119 		return -EINVAL;
120 	}
121 	b = b/a;
122 	if (b > 0xFF)
123 		return -EINVAL;
124 	data->pwm[pwm] = b;
125 	data->psc[pwm] = blink;
126 	return 0;
127 }
128 
129 static int pca9532_setpwm(struct i2c_client *client, int pwm)
130 {
131 	struct pca9532_data *data = i2c_get_clientdata(client);
132 	u8 maxleds = data->chip_info->num_leds;
133 
134 	mutex_lock(&data->update_lock);
135 	i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, pwm),
136 		data->pwm[pwm]);
137 	i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, pwm),
138 		data->psc[pwm]);
139 	mutex_unlock(&data->update_lock);
140 	return 0;
141 }
142 
143 /* Set LED routing */
144 static void pca9532_setled(struct pca9532_led *led)
145 {
146 	struct i2c_client *client = led->client;
147 	struct pca9532_data *data = i2c_get_clientdata(client);
148 	u8 maxleds = data->chip_info->num_leds;
149 	char reg;
150 
151 	mutex_lock(&data->update_lock);
152 	reg = i2c_smbus_read_byte_data(client, LED_REG(maxleds, led->id));
153 	/* zero led bits */
154 	reg = reg & ~(0x3<<LED_NUM(led->id)*2);
155 	/* set the new value */
156 	reg = reg | (led->state << LED_NUM(led->id)*2);
157 	i2c_smbus_write_byte_data(client, LED_REG(maxleds, led->id), reg);
158 	mutex_unlock(&data->update_lock);
159 }
160 
161 static void pca9532_set_brightness(struct led_classdev *led_cdev,
162 	enum led_brightness value)
163 {
164 	int err = 0;
165 	struct pca9532_led *led = ldev_to_led(led_cdev);
166 
167 	if (value == LED_OFF)
168 		led->state = PCA9532_OFF;
169 	else if (value == LED_FULL)
170 		led->state = PCA9532_ON;
171 	else {
172 		led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
173 		err = pca9532_calcpwm(led->client, 0, 0, value);
174 		if (err)
175 			return; /* XXX: led api doesn't allow error code? */
176 	}
177 	schedule_work(&led->work);
178 }
179 
180 static int pca9532_set_blink(struct led_classdev *led_cdev,
181 	unsigned long *delay_on, unsigned long *delay_off)
182 {
183 	struct pca9532_led *led = ldev_to_led(led_cdev);
184 	struct i2c_client *client = led->client;
185 	int psc;
186 	int err = 0;
187 
188 	if (*delay_on == 0 && *delay_off == 0) {
189 		/* led subsystem ask us for a blink rate */
190 		*delay_on = 1000;
191 		*delay_off = 1000;
192 	}
193 	if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
194 		return -EINVAL;
195 
196 	/* Thecus specific: only use PSC/PWM 0 */
197 	psc = (*delay_on * 152-1)/1000;
198 	err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
199 	if (err)
200 		return err;
201 	schedule_work(&led->work);
202 	return 0;
203 }
204 
205 static int pca9532_event(struct input_dev *dev, unsigned int type,
206 	unsigned int code, int value)
207 {
208 	struct pca9532_data *data = input_get_drvdata(dev);
209 
210 	if (!(type == EV_SND && (code == SND_BELL || code == SND_TONE)))
211 		return -1;
212 
213 	/* XXX: allow different kind of beeps with psc/pwm modifications */
214 	if (value > 1 && value < 32767)
215 		data->pwm[1] = 127;
216 	else
217 		data->pwm[1] = 0;
218 
219 	schedule_work(&data->work);
220 
221 	return 0;
222 }
223 
224 static void pca9532_input_work(struct work_struct *work)
225 {
226 	struct pca9532_data *data =
227 		container_of(work, struct pca9532_data, work);
228 	u8 maxleds = data->chip_info->num_leds;
229 
230 	mutex_lock(&data->update_lock);
231 	i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(maxleds, 1),
232 		data->pwm[1]);
233 	mutex_unlock(&data->update_lock);
234 }
235 
236 static void pca9532_led_work(struct work_struct *work)
237 {
238 	struct pca9532_led *led;
239 	led = container_of(work, struct pca9532_led, work);
240 	if (led->state == PCA9532_PWM0)
241 		pca9532_setpwm(led->client, 0);
242 	pca9532_setled(led);
243 }
244 
245 #ifdef CONFIG_LEDS_PCA9532_GPIO
246 static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
247 {
248 	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
249 	struct pca9532_led *led = &data->leds[offset];
250 
251 	if (led->type == PCA9532_TYPE_GPIO)
252 		return 0;
253 
254 	return -EBUSY;
255 }
256 
257 static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned offset, int val)
258 {
259 	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
260 	struct pca9532_led *led = &data->leds[offset];
261 
262 	if (val)
263 		led->state = PCA9532_ON;
264 	else
265 		led->state = PCA9532_OFF;
266 
267 	pca9532_setled(led);
268 }
269 
270 static int pca9532_gpio_get_value(struct gpio_chip *gc, unsigned offset)
271 {
272 	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
273 	unsigned char reg;
274 
275 	reg = i2c_smbus_read_byte_data(data->client, PCA9532_REG_INPUT(offset));
276 
277 	return !!(reg & (1 << (offset % 8)));
278 }
279 
280 static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
281 {
282 	/* To use as input ensure pin is not driven */
283 	pca9532_gpio_set_value(gc, offset, 0);
284 
285 	return 0;
286 }
287 
288 static int pca9532_gpio_direction_output(struct gpio_chip *gc, unsigned offset, int val)
289 {
290 	pca9532_gpio_set_value(gc, offset, val);
291 
292 	return 0;
293 }
294 #endif /* CONFIG_LEDS_PCA9532_GPIO */
295 
296 static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
297 {
298 	int i = n_devs;
299 
300 	if (!data)
301 		return -EINVAL;
302 
303 	while (--i >= 0) {
304 		switch (data->leds[i].type) {
305 		case PCA9532_TYPE_NONE:
306 		case PCA9532_TYPE_GPIO:
307 			break;
308 		case PCA9532_TYPE_LED:
309 			led_classdev_unregister(&data->leds[i].ldev);
310 			cancel_work_sync(&data->leds[i].work);
311 			break;
312 		case PCA9532_TYPE_N2100_BEEP:
313 			if (data->idev != NULL) {
314 				cancel_work_sync(&data->work);
315 				data->idev = NULL;
316 			}
317 			break;
318 		}
319 	}
320 
321 #ifdef CONFIG_LEDS_PCA9532_GPIO
322 	if (data->gpio.dev) {
323 		int err = gpiochip_remove(&data->gpio);
324 		if (err) {
325 			dev_err(&data->client->dev, "%s failed, %d\n",
326 						"gpiochip_remove()", err);
327 			return err;
328 		}
329 	}
330 #endif
331 
332 	return 0;
333 }
334 
335 static int pca9532_configure(struct i2c_client *client,
336 	struct pca9532_data *data, struct pca9532_platform_data *pdata)
337 {
338 	int i, err = 0;
339 	int gpios = 0;
340 	u8 maxleds = data->chip_info->num_leds;
341 
342 	for (i = 0; i < 2; i++)	{
343 		data->pwm[i] = pdata->pwm[i];
344 		data->psc[i] = pdata->psc[i];
345 		i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i),
346 			data->pwm[i]);
347 		i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i),
348 			data->psc[i]);
349 	}
350 
351 	for (i = 0; i < data->chip_info->num_leds; i++) {
352 		struct pca9532_led *led = &data->leds[i];
353 		struct pca9532_led *pled = &pdata->leds[i];
354 		led->client = client;
355 		led->id = i;
356 		led->type = pled->type;
357 		switch (led->type) {
358 		case PCA9532_TYPE_NONE:
359 			break;
360 		case PCA9532_TYPE_GPIO:
361 			gpios++;
362 			break;
363 		case PCA9532_TYPE_LED:
364 			led->state = pled->state;
365 			led->name = pled->name;
366 			led->ldev.name = led->name;
367 			led->ldev.brightness = LED_OFF;
368 			led->ldev.brightness_set = pca9532_set_brightness;
369 			led->ldev.blink_set = pca9532_set_blink;
370 			INIT_WORK(&led->work, pca9532_led_work);
371 			err = led_classdev_register(&client->dev, &led->ldev);
372 			if (err < 0) {
373 				dev_err(&client->dev,
374 					"couldn't register LED %s\n",
375 					led->name);
376 				goto exit;
377 			}
378 			pca9532_setled(led);
379 			break;
380 		case PCA9532_TYPE_N2100_BEEP:
381 			BUG_ON(data->idev);
382 			led->state = PCA9532_PWM1;
383 			pca9532_setled(led);
384 			data->idev = devm_input_allocate_device(&client->dev);
385 			if (data->idev == NULL) {
386 				err = -ENOMEM;
387 				goto exit;
388 			}
389 			data->idev->name = pled->name;
390 			data->idev->phys = "i2c/pca9532";
391 			data->idev->id.bustype = BUS_HOST;
392 			data->idev->id.vendor = 0x001f;
393 			data->idev->id.product = 0x0001;
394 			data->idev->id.version = 0x0100;
395 			data->idev->evbit[0] = BIT_MASK(EV_SND);
396 			data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
397 						BIT_MASK(SND_TONE);
398 			data->idev->event = pca9532_event;
399 			input_set_drvdata(data->idev, data);
400 			INIT_WORK(&data->work, pca9532_input_work);
401 			err = input_register_device(data->idev);
402 			if (err) {
403 				cancel_work_sync(&data->work);
404 				data->idev = NULL;
405 				goto exit;
406 			}
407 			break;
408 		}
409 	}
410 
411 #ifdef CONFIG_LEDS_PCA9532_GPIO
412 	if (gpios) {
413 		data->gpio.label = "gpio-pca9532";
414 		data->gpio.direction_input = pca9532_gpio_direction_input;
415 		data->gpio.direction_output = pca9532_gpio_direction_output;
416 		data->gpio.set = pca9532_gpio_set_value;
417 		data->gpio.get = pca9532_gpio_get_value;
418 		data->gpio.request = pca9532_gpio_request_pin;
419 		data->gpio.can_sleep = 1;
420 		data->gpio.base = pdata->gpio_base;
421 		data->gpio.ngpio = data->chip_info->num_leds;
422 		data->gpio.dev = &client->dev;
423 		data->gpio.owner = THIS_MODULE;
424 
425 		err = gpiochip_add(&data->gpio);
426 		if (err) {
427 			/* Use data->gpio.dev as a flag for freeing gpiochip */
428 			data->gpio.dev = NULL;
429 			dev_warn(&client->dev, "could not add gpiochip\n");
430 		} else {
431 			dev_info(&client->dev, "gpios %i...%i\n",
432 				data->gpio.base, data->gpio.base +
433 				data->gpio.ngpio - 1);
434 		}
435 	}
436 #endif
437 
438 	return 0;
439 
440 exit:
441 	pca9532_destroy_devices(data, i);
442 	return err;
443 }
444 
445 static int pca9532_probe(struct i2c_client *client,
446 	const struct i2c_device_id *id)
447 {
448 	struct pca9532_data *data = i2c_get_clientdata(client);
449 	struct pca9532_platform_data *pca9532_pdata =
450 			dev_get_platdata(&client->dev);
451 
452 	if (!pca9532_pdata)
453 		return -EIO;
454 
455 	if (!i2c_check_functionality(client->adapter,
456 		I2C_FUNC_SMBUS_BYTE_DATA))
457 		return -EIO;
458 
459 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
460 	if (!data)
461 		return -ENOMEM;
462 
463 	data->chip_info = &pca9532_chip_info_tbl[id->driver_data];
464 
465 	dev_info(&client->dev, "setting platform data\n");
466 	i2c_set_clientdata(client, data);
467 	data->client = client;
468 	mutex_init(&data->update_lock);
469 
470 	return pca9532_configure(client, data, pca9532_pdata);
471 }
472 
473 static int pca9532_remove(struct i2c_client *client)
474 {
475 	struct pca9532_data *data = i2c_get_clientdata(client);
476 	int err;
477 
478 	err = pca9532_destroy_devices(data, data->chip_info->num_leds);
479 	if (err)
480 		return err;
481 
482 	return 0;
483 }
484 
485 module_i2c_driver(pca9532_driver);
486 
487 MODULE_AUTHOR("Riku Voipio");
488 MODULE_LICENSE("GPL");
489 MODULE_DESCRIPTION("PCA 9532 LED dimmer");
490