leds-pca9532.c revision b26e0ed4936b743b693a4cc1413561fa3e4eaf65 
1/*
2 * pca9532.c - 16-bit Led dimmer
3 *
4 * Copyright (C) 2008 Riku Voipio
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * Datasheet: http://www.nxp.com/acrobat/datasheets/PCA9532_3.pdf
11 *
12 */
13
14#include <linux/module.h>
15#include <linux/i2c.h>
16#include <linux/leds.h>
17#include <linux/input.h>
18#include <linux/mutex.h>
19#include <linux/workqueue.h>
20#include <linux/leds-pca9532.h>
21
22static const unsigned short normal_i2c[] = { /*0x60,*/ I2C_CLIENT_END};
23I2C_CLIENT_INSMOD_1(pca9532);
24
25#define PCA9532_REG_PSC(i) (0x2+(i)*2)
26#define PCA9532_REG_PWM(i) (0x3+(i)*2)
27#define PCA9532_REG_LS0  0x6
28#define LED_REG(led) ((led>>2)+PCA9532_REG_LS0)
29#define LED_NUM(led) (led & 0x3)
30
31#define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)
32
33struct pca9532_data {
34	struct i2c_client *client;
35	struct pca9532_led leds[16];
36	struct mutex update_lock;
37	struct input_dev    *idev;
38       struct work_struct work;
39	u8 pwm[2];
40	u8 psc[2];
41};
42
43static int pca9532_probe(struct i2c_client *client,
44	const struct i2c_device_id *id);
45static int pca9532_remove(struct i2c_client *client);
46
47static const struct i2c_device_id pca9532_id[] = {
48	{ "pca9532", 0 },
49	{ }
50};
51
52MODULE_DEVICE_TABLE(i2c, pca9532_id);
53
54static struct i2c_driver pca9532_driver = {
55	.driver = {
56		.name   = "pca9532",
57	},
58	.probe  = pca9532_probe,
59	.remove = pca9532_remove,
60	.id_table = pca9532_id,
61};
62
63/* We have two pwm/blinkers, but 16 possible leds to drive. Additionaly,
64 * the clever Thecus people are using one pwm to drive the beeper. So,
65 * as a compromise we average one pwm to the values requested by all
66 * leds that are not ON/OFF.
67 * */
68static int pca9532_calcpwm(struct i2c_client *client, int pwm, int blink,
69	enum led_brightness value)
70{
71	int a = 0, b = 0, i = 0;
72	struct pca9532_data *data = i2c_get_clientdata(client);
73	for (i = 0; i < 16; i++) {
74		if (data->leds[i].type == PCA9532_TYPE_LED &&
75			data->leds[i].state == PCA9532_PWM0+pwm) {
76				a++;
77				b += data->leds[i].ldev.brightness;
78		}
79	}
80	if (a == 0) {
81		dev_err(&client->dev,
82		"fear of division by zero %d/%d, wanted %d\n",
83			b, a, value);
84		return -EINVAL;
85	}
86	b = b/a;
87	if (b > 0xFF)
88		return -EINVAL;
89	data->pwm[pwm] = b;
90       data->psc[pwm] = blink;
91       return 0;
92}
93
94static int pca9532_setpwm(struct i2c_client *client, int pwm)
95{
96       struct pca9532_data *data = i2c_get_clientdata(client);
97       mutex_lock(&data->update_lock);
98	i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(pwm),
99		data->pwm[pwm]);
100	i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(pwm),
101		data->psc[pwm]);
102	mutex_unlock(&data->update_lock);
103	return 0;
104}
105
106/* Set LED routing */
107static void pca9532_setled(struct pca9532_led *led)
108{
109	struct i2c_client *client = led->client;
110	struct pca9532_data *data = i2c_get_clientdata(client);
111	char reg;
112
113	mutex_lock(&data->update_lock);
114	reg = i2c_smbus_read_byte_data(client, LED_REG(led->id));
115	/* zero led bits */
116	reg = reg & ~(0x3<<LED_NUM(led->id)*2);
117	/* set the new value */
118	reg = reg | (led->state << LED_NUM(led->id)*2);
119	i2c_smbus_write_byte_data(client, LED_REG(led->id), reg);
120	mutex_unlock(&data->update_lock);
121}
122
123static void pca9532_set_brightness(struct led_classdev *led_cdev,
124	enum led_brightness value)
125{
126	int err = 0;
127	struct pca9532_led *led = ldev_to_led(led_cdev);
128
129	if (value == LED_OFF)
130		led->state = PCA9532_OFF;
131	else if (value == LED_FULL)
132		led->state = PCA9532_ON;
133	else {
134		led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
135               err = pca9532_calcpwm(led->client, 0, 0, value);
136		if (err)
137			return; /* XXX: led api doesn't allow error code? */
138	}
139       schedule_work(&led->work);
140}
141
142static int pca9532_set_blink(struct led_classdev *led_cdev,
143	unsigned long *delay_on, unsigned long *delay_off)
144{
145	struct pca9532_led *led = ldev_to_led(led_cdev);
146	struct i2c_client *client = led->client;
147	int psc;
148       int err = 0;
149
150	if (*delay_on == 0 && *delay_off == 0) {
151	/* led subsystem ask us for a blink rate */
152		*delay_on  = 1000;
153		*delay_off = 1000;
154	}
155	if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
156		return -EINVAL;
157
158	/* Thecus specific: only use PSC/PWM 0 */
159	psc = (*delay_on * 152-1)/1000;
160       err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
161       if (err)
162               return err;
163       schedule_work(&led->work);
164       return 0;
165}
166
167static int pca9532_event(struct input_dev *dev, unsigned int type,
168	unsigned int code, int value)
169{
170	struct pca9532_data *data = input_get_drvdata(dev);
171
172	if (type != EV_SND && (code != SND_BELL || code != SND_TONE))
173		return -1;
174
175	/* XXX: allow different kind of beeps with psc/pwm modifications */
176	if (value > 1 && value < 32767)
177		data->pwm[1] = 127;
178	else
179		data->pwm[1] = 0;
180
181       schedule_work(&data->work);
182
183       return 0;
184}
185
186static void pca9532_input_work(struct work_struct *work)
187{
188       struct pca9532_data *data;
189       data = container_of(work, struct pca9532_data, work);
190	mutex_lock(&data->update_lock);
191	i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(1),
192		data->pwm[1]);
193	mutex_unlock(&data->update_lock);
194}
195
196static void pca9532_led_work(struct work_struct *work)
197{
198       struct pca9532_led *led;
199       led = container_of(work, struct pca9532_led, work);
200       if (led->state == PCA9532_PWM0)
201               pca9532_setpwm(led->client, 0);
202       pca9532_setled(led);
203}
204
205static int pca9532_configure(struct i2c_client *client,
206	struct pca9532_data *data, struct pca9532_platform_data *pdata)
207{
208	int i, err = 0;
209
210	for (i = 0; i < 2; i++)	{
211		data->pwm[i] = pdata->pwm[i];
212		data->psc[i] = pdata->psc[i];
213		i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(i),
214			data->pwm[i]);
215		i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(i),
216			data->psc[i]);
217	}
218
219	for (i = 0; i < 16; i++) {
220		struct pca9532_led *led = &data->leds[i];
221		struct pca9532_led *pled = &pdata->leds[i];
222		led->client = client;
223		led->id = i;
224		led->type = pled->type;
225		switch (led->type) {
226		case PCA9532_TYPE_NONE:
227			break;
228		case PCA9532_TYPE_LED:
229			led->state = pled->state;
230			led->name =  pled->name;
231			led->ldev.name = led->name;
232			led->ldev.brightness = LED_OFF;
233			led->ldev.brightness_set = pca9532_set_brightness;
234			led->ldev.blink_set = pca9532_set_blink;
235                       INIT_WORK(&led->work, pca9532_led_work);
236			err = led_classdev_register(&client->dev, &led->ldev);
237			if (err < 0) {
238				dev_err(&client->dev,
239					"couldn't register LED %s\n",
240					led->name);
241				goto exit;
242			}
243			pca9532_setled(led);
244			break;
245		case PCA9532_TYPE_N2100_BEEP:
246			BUG_ON(data->idev);
247			led->state = PCA9532_PWM1;
248			pca9532_setled(led);
249			data->idev = input_allocate_device();
250			if (data->idev == NULL) {
251				err = -ENOMEM;
252				goto exit;
253			}
254			data->idev->name = pled->name;
255			data->idev->phys = "i2c/pca9532";
256			data->idev->id.bustype = BUS_HOST;
257			data->idev->id.vendor  = 0x001f;
258			data->idev->id.product = 0x0001;
259			data->idev->id.version = 0x0100;
260			data->idev->evbit[0] = BIT_MASK(EV_SND);
261			data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
262						BIT_MASK(SND_TONE);
263			data->idev->event = pca9532_event;
264			input_set_drvdata(data->idev, data);
265                       INIT_WORK(&data->work, pca9532_input_work);
266			err = input_register_device(data->idev);
267			if (err) {
268				input_free_device(data->idev);
269                               cancel_work_sync(&data->work);
270				data->idev = NULL;
271				goto exit;
272			}
273			break;
274		}
275	}
276	return 0;
277
278exit:
279	if (i > 0)
280		for (i = i - 1; i >= 0; i--)
281			switch (data->leds[i].type) {
282			case PCA9532_TYPE_NONE:
283				break;
284			case PCA9532_TYPE_LED:
285				led_classdev_unregister(&data->leds[i].ldev);
286                               cancel_work_sync(&data->leds[i].work);
287				break;
288			case PCA9532_TYPE_N2100_BEEP:
289				if (data->idev != NULL) {
290					input_unregister_device(data->idev);
291					input_free_device(data->idev);
292                                       cancel_work_sync(&data->work);
293					data->idev = NULL;
294				}
295				break;
296			}
297
298	return err;
299}
300
301static int pca9532_probe(struct i2c_client *client,
302	const struct i2c_device_id *id)
303{
304	struct pca9532_data *data = i2c_get_clientdata(client);
305	struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;
306	int err;
307
308	if (!pca9532_pdata)
309		return -EIO;
310
311	if (!i2c_check_functionality(client->adapter,
312		I2C_FUNC_SMBUS_BYTE_DATA))
313		return -EIO;
314
315	data = kzalloc(sizeof(*data), GFP_KERNEL);
316	if (!data)
317		return -ENOMEM;
318
319	dev_info(&client->dev, "setting platform data\n");
320	i2c_set_clientdata(client, data);
321	data->client = client;
322	mutex_init(&data->update_lock);
323
324	err = pca9532_configure(client, data, pca9532_pdata);
325	if (err) {
326		kfree(data);
327		i2c_set_clientdata(client, NULL);
328	}
329
330	return err;
331}
332
333static int pca9532_remove(struct i2c_client *client)
334{
335	struct pca9532_data *data = i2c_get_clientdata(client);
336	int i;
337	for (i = 0; i < 16; i++)
338		switch (data->leds[i].type) {
339		case PCA9532_TYPE_NONE:
340			break;
341		case PCA9532_TYPE_LED:
342			led_classdev_unregister(&data->leds[i].ldev);
343                       cancel_work_sync(&data->leds[i].work);
344			break;
345		case PCA9532_TYPE_N2100_BEEP:
346			if (data->idev != NULL) {
347				input_unregister_device(data->idev);
348				input_free_device(data->idev);
349                               cancel_work_sync(&data->work);
350				data->idev = NULL;
351			}
352			break;
353		}
354
355	kfree(data);
356	i2c_set_clientdata(client, NULL);
357	return 0;
358}
359
360static int __init pca9532_init(void)
361{
362	return i2c_add_driver(&pca9532_driver);
363}
364
365static void __exit pca9532_exit(void)
366{
367	i2c_del_driver(&pca9532_driver);
368}
369
370MODULE_AUTHOR("Riku Voipio");
371MODULE_LICENSE("GPL");
372MODULE_DESCRIPTION("PCA 9532 LED dimmer");
373
374module_init(pca9532_init);
375module_exit(pca9532_exit);
376
377