xref: /openbmc/linux/drivers/leds/leds-pca9532.c (revision a8fe58ce)
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 int 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 err;
176 	}
177 	if (led->state == PCA9532_PWM0)
178 		pca9532_setpwm(led->client, 0);
179 	pca9532_setled(led);
180 	return err;
181 }
182 
183 static int pca9532_set_blink(struct led_classdev *led_cdev,
184 	unsigned long *delay_on, unsigned long *delay_off)
185 {
186 	struct pca9532_led *led = ldev_to_led(led_cdev);
187 	struct i2c_client *client = led->client;
188 	int psc;
189 	int err = 0;
190 
191 	if (*delay_on == 0 && *delay_off == 0) {
192 		/* led subsystem ask us for a blink rate */
193 		*delay_on = 1000;
194 		*delay_off = 1000;
195 	}
196 	if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
197 		return -EINVAL;
198 
199 	/* Thecus specific: only use PSC/PWM 0 */
200 	psc = (*delay_on * 152-1)/1000;
201 	err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
202 	if (err)
203 		return err;
204 	if (led->state == PCA9532_PWM0)
205 		pca9532_setpwm(led->client, 0);
206 	pca9532_setled(led);
207 
208 	return 0;
209 }
210 
211 static int pca9532_event(struct input_dev *dev, unsigned int type,
212 	unsigned int code, int value)
213 {
214 	struct pca9532_data *data = input_get_drvdata(dev);
215 
216 	if (!(type == EV_SND && (code == SND_BELL || code == SND_TONE)))
217 		return -1;
218 
219 	/* XXX: allow different kind of beeps with psc/pwm modifications */
220 	if (value > 1 && value < 32767)
221 		data->pwm[1] = 127;
222 	else
223 		data->pwm[1] = 0;
224 
225 	schedule_work(&data->work);
226 
227 	return 0;
228 }
229 
230 static void pca9532_input_work(struct work_struct *work)
231 {
232 	struct pca9532_data *data =
233 		container_of(work, struct pca9532_data, work);
234 	u8 maxleds = data->chip_info->num_leds;
235 
236 	mutex_lock(&data->update_lock);
237 	i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(maxleds, 1),
238 		data->pwm[1]);
239 	mutex_unlock(&data->update_lock);
240 }
241 
242 #ifdef CONFIG_LEDS_PCA9532_GPIO
243 static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
244 {
245 	struct pca9532_data *data = gpiochip_get_data(gc);
246 	struct pca9532_led *led = &data->leds[offset];
247 
248 	if (led->type == PCA9532_TYPE_GPIO)
249 		return 0;
250 
251 	return -EBUSY;
252 }
253 
254 static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned offset, int val)
255 {
256 	struct pca9532_data *data = gpiochip_get_data(gc);
257 	struct pca9532_led *led = &data->leds[offset];
258 
259 	if (val)
260 		led->state = PCA9532_ON;
261 	else
262 		led->state = PCA9532_OFF;
263 
264 	pca9532_setled(led);
265 }
266 
267 static int pca9532_gpio_get_value(struct gpio_chip *gc, unsigned offset)
268 {
269 	struct pca9532_data *data = gpiochip_get_data(gc);
270 	unsigned char reg;
271 
272 	reg = i2c_smbus_read_byte_data(data->client, PCA9532_REG_INPUT(offset));
273 
274 	return !!(reg & (1 << (offset % 8)));
275 }
276 
277 static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
278 {
279 	/* To use as input ensure pin is not driven */
280 	pca9532_gpio_set_value(gc, offset, 0);
281 
282 	return 0;
283 }
284 
285 static int pca9532_gpio_direction_output(struct gpio_chip *gc, unsigned offset, int val)
286 {
287 	pca9532_gpio_set_value(gc, offset, val);
288 
289 	return 0;
290 }
291 #endif /* CONFIG_LEDS_PCA9532_GPIO */
292 
293 static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
294 {
295 	int i = n_devs;
296 
297 	if (!data)
298 		return -EINVAL;
299 
300 	while (--i >= 0) {
301 		switch (data->leds[i].type) {
302 		case PCA9532_TYPE_NONE:
303 		case PCA9532_TYPE_GPIO:
304 			break;
305 		case PCA9532_TYPE_LED:
306 			led_classdev_unregister(&data->leds[i].ldev);
307 			break;
308 		case PCA9532_TYPE_N2100_BEEP:
309 			if (data->idev != NULL) {
310 				cancel_work_sync(&data->work);
311 				data->idev = NULL;
312 			}
313 			break;
314 		}
315 	}
316 
317 #ifdef CONFIG_LEDS_PCA9532_GPIO
318 	if (data->gpio.parent)
319 		gpiochip_remove(&data->gpio);
320 #endif
321 
322 	return 0;
323 }
324 
325 static int pca9532_configure(struct i2c_client *client,
326 	struct pca9532_data *data, struct pca9532_platform_data *pdata)
327 {
328 	int i, err = 0;
329 	int gpios = 0;
330 	u8 maxleds = data->chip_info->num_leds;
331 
332 	for (i = 0; i < 2; i++)	{
333 		data->pwm[i] = pdata->pwm[i];
334 		data->psc[i] = pdata->psc[i];
335 		i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i),
336 			data->pwm[i]);
337 		i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i),
338 			data->psc[i]);
339 	}
340 
341 	for (i = 0; i < data->chip_info->num_leds; i++) {
342 		struct pca9532_led *led = &data->leds[i];
343 		struct pca9532_led *pled = &pdata->leds[i];
344 		led->client = client;
345 		led->id = i;
346 		led->type = pled->type;
347 		switch (led->type) {
348 		case PCA9532_TYPE_NONE:
349 			break;
350 		case PCA9532_TYPE_GPIO:
351 			gpios++;
352 			break;
353 		case PCA9532_TYPE_LED:
354 			led->state = pled->state;
355 			led->name = pled->name;
356 			led->ldev.name = led->name;
357 			led->ldev.brightness = LED_OFF;
358 			led->ldev.brightness_set_blocking =
359 						pca9532_set_brightness;
360 			led->ldev.blink_set = pca9532_set_blink;
361 			err = led_classdev_register(&client->dev, &led->ldev);
362 			if (err < 0) {
363 				dev_err(&client->dev,
364 					"couldn't register LED %s\n",
365 					led->name);
366 				goto exit;
367 			}
368 			pca9532_setled(led);
369 			break;
370 		case PCA9532_TYPE_N2100_BEEP:
371 			BUG_ON(data->idev);
372 			led->state = PCA9532_PWM1;
373 			pca9532_setled(led);
374 			data->idev = devm_input_allocate_device(&client->dev);
375 			if (data->idev == NULL) {
376 				err = -ENOMEM;
377 				goto exit;
378 			}
379 			data->idev->name = pled->name;
380 			data->idev->phys = "i2c/pca9532";
381 			data->idev->id.bustype = BUS_HOST;
382 			data->idev->id.vendor = 0x001f;
383 			data->idev->id.product = 0x0001;
384 			data->idev->id.version = 0x0100;
385 			data->idev->evbit[0] = BIT_MASK(EV_SND);
386 			data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
387 						BIT_MASK(SND_TONE);
388 			data->idev->event = pca9532_event;
389 			input_set_drvdata(data->idev, data);
390 			INIT_WORK(&data->work, pca9532_input_work);
391 			err = input_register_device(data->idev);
392 			if (err) {
393 				cancel_work_sync(&data->work);
394 				data->idev = NULL;
395 				goto exit;
396 			}
397 			break;
398 		}
399 	}
400 
401 #ifdef CONFIG_LEDS_PCA9532_GPIO
402 	if (gpios) {
403 		data->gpio.label = "gpio-pca9532";
404 		data->gpio.direction_input = pca9532_gpio_direction_input;
405 		data->gpio.direction_output = pca9532_gpio_direction_output;
406 		data->gpio.set = pca9532_gpio_set_value;
407 		data->gpio.get = pca9532_gpio_get_value;
408 		data->gpio.request = pca9532_gpio_request_pin;
409 		data->gpio.can_sleep = 1;
410 		data->gpio.base = pdata->gpio_base;
411 		data->gpio.ngpio = data->chip_info->num_leds;
412 		data->gpio.parent = &client->dev;
413 		data->gpio.owner = THIS_MODULE;
414 
415 		err = gpiochip_add_data(&data->gpio, data);
416 		if (err) {
417 			/* Use data->gpio.dev as a flag for freeing gpiochip */
418 			data->gpio.parent = NULL;
419 			dev_warn(&client->dev, "could not add gpiochip\n");
420 		} else {
421 			dev_info(&client->dev, "gpios %i...%i\n",
422 				data->gpio.base, data->gpio.base +
423 				data->gpio.ngpio - 1);
424 		}
425 	}
426 #endif
427 
428 	return 0;
429 
430 exit:
431 	pca9532_destroy_devices(data, i);
432 	return err;
433 }
434 
435 static int pca9532_probe(struct i2c_client *client,
436 	const struct i2c_device_id *id)
437 {
438 	struct pca9532_data *data = i2c_get_clientdata(client);
439 	struct pca9532_platform_data *pca9532_pdata =
440 			dev_get_platdata(&client->dev);
441 
442 	if (!pca9532_pdata)
443 		return -EIO;
444 
445 	if (!i2c_check_functionality(client->adapter,
446 		I2C_FUNC_SMBUS_BYTE_DATA))
447 		return -EIO;
448 
449 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
450 	if (!data)
451 		return -ENOMEM;
452 
453 	data->chip_info = &pca9532_chip_info_tbl[id->driver_data];
454 
455 	dev_info(&client->dev, "setting platform data\n");
456 	i2c_set_clientdata(client, data);
457 	data->client = client;
458 	mutex_init(&data->update_lock);
459 
460 	return pca9532_configure(client, data, pca9532_pdata);
461 }
462 
463 static int pca9532_remove(struct i2c_client *client)
464 {
465 	struct pca9532_data *data = i2c_get_clientdata(client);
466 	int err;
467 
468 	err = pca9532_destroy_devices(data, data->chip_info->num_leds);
469 	if (err)
470 		return err;
471 
472 	return 0;
473 }
474 
475 module_i2c_driver(pca9532_driver);
476 
477 MODULE_AUTHOR("Riku Voipio");
478 MODULE_LICENSE("GPL");
479 MODULE_DESCRIPTION("PCA 9532 LED dimmer");
480