leds-pca9532.c revision 8614fb46637a993258146022b0140d553132a0b7 
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
35struct pca9532_chip_info {
36	u8	num_leds;
37};
38
39struct 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
53static int pca9532_probe(struct i2c_client *client,
54	const struct i2c_device_id *id);
55static int pca9532_remove(struct i2c_client *client);
56
57enum {
58	pca9530,
59	pca9531,
60	pca9532,
61	pca9533,
62};
63
64static const struct i2c_device_id pca9532_id[] = {
65	{ "pca9530", pca9530 },
66	{ "pca9531", pca9531 },
67	{ "pca9532", pca9532 },
68	{ "pca9533", pca9533 },
69	{ }
70};
71
72MODULE_DEVICE_TABLE(i2c, pca9532_id);
73
74static 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
89static 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 * */
103static 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
129static 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 */
144static 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
161static 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
180static 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
205static 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
224static 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
236static 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
246static 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
257static 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
270static 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
280static 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
288static 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
296static 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
335static 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
440exit:
441	pca9532_destroy_devices(data, i);
442	return err;
443}
444
445static 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 = client->dev.platform_data;
450
451	if (!pca9532_pdata)
452		return -EIO;
453
454	if (!i2c_check_functionality(client->adapter,
455		I2C_FUNC_SMBUS_BYTE_DATA))
456		return -EIO;
457
458	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
459	if (!data)
460		return -ENOMEM;
461
462	data->chip_info = &pca9532_chip_info_tbl[id->driver_data];
463
464	dev_info(&client->dev, "setting platform data\n");
465	i2c_set_clientdata(client, data);
466	data->client = client;
467	mutex_init(&data->update_lock);
468
469	return pca9532_configure(client, data, pca9532_pdata);
470}
471
472static int pca9532_remove(struct i2c_client *client)
473{
474	struct pca9532_data *data = i2c_get_clientdata(client);
475	int err;
476
477	err = pca9532_destroy_devices(data, data->chip_info->num_leds);
478	if (err)
479		return err;
480
481	return 0;
482}
483
484module_i2c_driver(pca9532_driver);
485
486MODULE_AUTHOR("Riku Voipio");
487MODULE_LICENSE("GPL");
488MODULE_DESCRIPTION("PCA 9532 LED dimmer");
489