leds-pca9532.c revision 77279862bad879c1c194171f5cf6b5b0e7abe384 
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
22#define PCA9532_REG_PSC(i) (0x2+(i)*2)
23#define PCA9532_REG_PWM(i) (0x3+(i)*2)
24#define PCA9532_REG_LS0  0x6
25#define LED_REG(led) ((led>>2)+PCA9532_REG_LS0)
26#define LED_NUM(led) (led & 0x3)
27
28#define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)
29
30struct pca9532_data {
31	struct i2c_client *client;
32	struct pca9532_led leds[16];
33	struct mutex update_lock;
34	struct input_dev *idev;
35	struct work_struct work;
36	u8 pwm[2];
37	u8 psc[2];
38};
39
40static int pca9532_probe(struct i2c_client *client,
41	const struct i2c_device_id *id);
42static int pca9532_remove(struct i2c_client *client);
43
44static const struct i2c_device_id pca9532_id[] = {
45	{ "pca9532", 0 },
46	{ }
47};
48
49MODULE_DEVICE_TABLE(i2c, pca9532_id);
50
51static struct i2c_driver pca9532_driver = {
52	.driver = {
53		.name = "pca9532",
54	},
55	.probe = pca9532_probe,
56	.remove = pca9532_remove,
57	.id_table = pca9532_id,
58};
59
60/* We have two pwm/blinkers, but 16 possible leds to drive. Additionaly,
61 * the clever Thecus people are using one pwm to drive the beeper. So,
62 * as a compromise we average one pwm to the values requested by all
63 * leds that are not ON/OFF.
64 * */
65static int pca9532_calcpwm(struct i2c_client *client, int pwm, int blink,
66	enum led_brightness value)
67{
68	int a = 0, b = 0, i = 0;
69	struct pca9532_data *data = i2c_get_clientdata(client);
70	for (i = 0; i < 16; i++) {
71		if (data->leds[i].type == PCA9532_TYPE_LED &&
72			data->leds[i].state == PCA9532_PWM0+pwm) {
73				a++;
74				b += data->leds[i].ldev.brightness;
75		}
76	}
77	if (a == 0) {
78		dev_err(&client->dev,
79		"fear of division by zero %d/%d, wanted %d\n",
80			b, a, value);
81		return -EINVAL;
82	}
83	b = b/a;
84	if (b > 0xFF)
85		return -EINVAL;
86	data->pwm[pwm] = b;
87	data->psc[pwm] = blink;
88	return 0;
89}
90
91static int pca9532_setpwm(struct i2c_client *client, int pwm)
92{
93	struct pca9532_data *data = i2c_get_clientdata(client);
94	mutex_lock(&data->update_lock);
95	i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(pwm),
96		data->pwm[pwm]);
97	i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(pwm),
98		data->psc[pwm]);
99	mutex_unlock(&data->update_lock);
100	return 0;
101}
102
103/* Set LED routing */
104static void pca9532_setled(struct pca9532_led *led)
105{
106	struct i2c_client *client = led->client;
107	struct pca9532_data *data = i2c_get_clientdata(client);
108	char reg;
109
110	mutex_lock(&data->update_lock);
111	reg = i2c_smbus_read_byte_data(client, LED_REG(led->id));
112	/* zero led bits */
113	reg = reg & ~(0x3<<LED_NUM(led->id)*2);
114	/* set the new value */
115	reg = reg | (led->state << LED_NUM(led->id)*2);
116	i2c_smbus_write_byte_data(client, LED_REG(led->id), reg);
117	mutex_unlock(&data->update_lock);
118}
119
120static void pca9532_set_brightness(struct led_classdev *led_cdev,
121	enum led_brightness value)
122{
123	int err = 0;
124	struct pca9532_led *led = ldev_to_led(led_cdev);
125
126	if (value == LED_OFF)
127		led->state = PCA9532_OFF;
128	else if (value == LED_FULL)
129		led->state = PCA9532_ON;
130	else {
131		led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
132		err = pca9532_calcpwm(led->client, 0, 0, value);
133		if (err)
134			return; /* XXX: led api doesn't allow error code? */
135	}
136	schedule_work(&led->work);
137}
138
139static int pca9532_set_blink(struct led_classdev *led_cdev,
140	unsigned long *delay_on, unsigned long *delay_off)
141{
142	struct pca9532_led *led = ldev_to_led(led_cdev);
143	struct i2c_client *client = led->client;
144	int psc;
145	int err = 0;
146
147	if (*delay_on == 0 && *delay_off == 0) {
148	/* led subsystem ask us for a blink rate */
149		*delay_on = 1000;
150		*delay_off = 1000;
151	}
152	if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
153		return -EINVAL;
154
155	/* Thecus specific: only use PSC/PWM 0 */
156	psc = (*delay_on * 152-1)/1000;
157	err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
158	if (err)
159		return err;
160	schedule_work(&led->work);
161	return 0;
162}
163
164static int pca9532_event(struct input_dev *dev, unsigned int type,
165	unsigned int code, int value)
166{
167	struct pca9532_data *data = input_get_drvdata(dev);
168
169	if (!(type == EV_SND && (code == SND_BELL || code == SND_TONE)))
170		return -1;
171
172	/* XXX: allow different kind of beeps with psc/pwm modifications */
173	if (value > 1 && value < 32767)
174		data->pwm[1] = 127;
175	else
176		data->pwm[1] = 0;
177
178	schedule_work(&data->work);
179
180	return 0;
181}
182
183static void pca9532_input_work(struct work_struct *work)
184{
185	struct pca9532_data *data;
186	data = container_of(work, struct pca9532_data, work);
187	mutex_lock(&data->update_lock);
188	i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(1),
189		data->pwm[1]);
190	mutex_unlock(&data->update_lock);
191}
192
193static void pca9532_led_work(struct work_struct *work)
194{
195	struct pca9532_led *led;
196	led = container_of(work, struct pca9532_led, work);
197	if (led->state == PCA9532_PWM0)
198		pca9532_setpwm(led->client, 0);
199	pca9532_setled(led);
200}
201
202static int pca9532_configure(struct i2c_client *client,
203	struct pca9532_data *data, struct pca9532_platform_data *pdata)
204{
205	int i, err = 0;
206
207	for (i = 0; i < 2; i++)	{
208		data->pwm[i] = pdata->pwm[i];
209		data->psc[i] = pdata->psc[i];
210		i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(i),
211			data->pwm[i]);
212		i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(i),
213			data->psc[i]);
214	}
215
216	for (i = 0; i < 16; i++) {
217		struct pca9532_led *led = &data->leds[i];
218		struct pca9532_led *pled = &pdata->leds[i];
219		led->client = client;
220		led->id = i;
221		led->type = pled->type;
222		switch (led->type) {
223		case PCA9532_TYPE_NONE:
224			break;
225		case PCA9532_TYPE_LED:
226			led->state = pled->state;
227			led->name = pled->name;
228			led->ldev.name = led->name;
229			led->ldev.brightness = LED_OFF;
230			led->ldev.brightness_set = pca9532_set_brightness;
231			led->ldev.blink_set = pca9532_set_blink;
232			INIT_WORK(&led->work, pca9532_led_work);
233			err = led_classdev_register(&client->dev, &led->ldev);
234			if (err < 0) {
235				dev_err(&client->dev,
236					"couldn't register LED %s\n",
237					led->name);
238				goto exit;
239			}
240			pca9532_setled(led);
241			break;
242		case PCA9532_TYPE_N2100_BEEP:
243			BUG_ON(data->idev);
244			led->state = PCA9532_PWM1;
245			pca9532_setled(led);
246			data->idev = input_allocate_device();
247			if (data->idev == NULL) {
248				err = -ENOMEM;
249				goto exit;
250			}
251			data->idev->name = pled->name;
252			data->idev->phys = "i2c/pca9532";
253			data->idev->id.bustype = BUS_HOST;
254			data->idev->id.vendor = 0x001f;
255			data->idev->id.product = 0x0001;
256			data->idev->id.version = 0x0100;
257			data->idev->evbit[0] = BIT_MASK(EV_SND);
258			data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
259						BIT_MASK(SND_TONE);
260			data->idev->event = pca9532_event;
261			input_set_drvdata(data->idev, data);
262			INIT_WORK(&data->work, pca9532_input_work);
263			err = input_register_device(data->idev);
264			if (err) {
265				input_free_device(data->idev);
266				cancel_work_sync(&data->work);
267				data->idev = NULL;
268				goto exit;
269			}
270			break;
271		}
272	}
273	return 0;
274
275exit:
276	if (i > 0)
277		for (i = i - 1; i >= 0; i--)
278			switch (data->leds[i].type) {
279			case PCA9532_TYPE_NONE:
280				break;
281			case PCA9532_TYPE_LED:
282				led_classdev_unregister(&data->leds[i].ldev);
283				cancel_work_sync(&data->leds[i].work);
284				break;
285			case PCA9532_TYPE_N2100_BEEP:
286				if (data->idev != NULL) {
287					input_unregister_device(data->idev);
288					input_free_device(data->idev);
289					cancel_work_sync(&data->work);
290					data->idev = NULL;
291				}
292				break;
293			}
294
295	return err;
296}
297
298static int pca9532_probe(struct i2c_client *client,
299	const struct i2c_device_id *id)
300{
301	struct pca9532_data *data = i2c_get_clientdata(client);
302	struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;
303	int err;
304
305	if (!pca9532_pdata)
306		return -EIO;
307
308	if (!i2c_check_functionality(client->adapter,
309		I2C_FUNC_SMBUS_BYTE_DATA))
310		return -EIO;
311
312	data = kzalloc(sizeof(*data), GFP_KERNEL);
313	if (!data)
314		return -ENOMEM;
315
316	dev_info(&client->dev, "setting platform data\n");
317	i2c_set_clientdata(client, data);
318	data->client = client;
319	mutex_init(&data->update_lock);
320
321	err = pca9532_configure(client, data, pca9532_pdata);
322	if (err) {
323		kfree(data);
324		i2c_set_clientdata(client, NULL);
325	}
326
327	return err;
328}
329
330static int pca9532_remove(struct i2c_client *client)
331{
332	struct pca9532_data *data = i2c_get_clientdata(client);
333	int i;
334	for (i = 0; i < 16; i++)
335		switch (data->leds[i].type) {
336		case PCA9532_TYPE_NONE:
337			break;
338		case PCA9532_TYPE_LED:
339			led_classdev_unregister(&data->leds[i].ldev);
340			cancel_work_sync(&data->leds[i].work);
341			break;
342		case PCA9532_TYPE_N2100_BEEP:
343			if (data->idev != NULL) {
344				input_unregister_device(data->idev);
345				input_free_device(data->idev);
346				cancel_work_sync(&data->work);
347				data->idev = NULL;
348			}
349			break;
350		}
351
352	kfree(data);
353	i2c_set_clientdata(client, NULL);
354	return 0;
355}
356
357static int __init pca9532_init(void)
358{
359	return i2c_add_driver(&pca9532_driver);
360}
361
362static void __exit pca9532_exit(void)
363{
364	i2c_del_driver(&pca9532_driver);
365}
366
367MODULE_AUTHOR("Riku Voipio");
368MODULE_LICENSE("GPL");
369MODULE_DESCRIPTION("PCA 9532 LED dimmer");
370
371module_init(pca9532_init);
372module_exit(pca9532_exit);
373
374