2 * Simple driver for Texas Instruments LM3630A Backlight driver chip
3 * Copyright (C) 2012 Texas Instruments
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/i2c.h>
13 #include <linux/backlight.h>
14 #include <linux/err.h>
15 #include <linux/delay.h>
16 #include <linux/uaccess.h>
17 #include <linux/interrupt.h>
18 #include <linux/regmap.h>
19 #include <linux/pwm.h>
20 #include <linux/platform_data/lm3630a_bl.h>
23 #define REG_BOOST 0x02
24 #define REG_CONFIG 0x01
25 #define REG_BRT_A 0x03
26 #define REG_BRT_B 0x04
29 #define REG_INT_STATUS 0x09
30 #define REG_INT_EN 0x0A
31 #define REG_FAULT 0x0B
32 #define REG_PWM_OUTLOW 0x12
33 #define REG_PWM_OUTHIGH 0x13
36 #define INT_DEBOUNCE_MSEC 10
39 struct delayed_work work;
42 struct workqueue_struct *irqthread;
43 struct lm3630a_platform_data *pdata;
44 struct backlight_device *bleda;
45 struct backlight_device *bledb;
46 struct regmap *regmap;
47 struct pwm_device *pwmd;
51 static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
56 rval = regmap_read(pchip->regmap, reg, ®_val);
59 return reg_val & 0xFF;
62 static int lm3630a_write(struct lm3630a_chip *pchip,
63 unsigned int reg, unsigned int data)
65 return regmap_write(pchip->regmap, reg, data);
68 static int lm3630a_update(struct lm3630a_chip *pchip,
69 unsigned int reg, unsigned int mask,
72 return regmap_update_bits(pchip->regmap, reg, mask, data);
76 static int lm3630a_chip_init(struct lm3630a_chip *pchip)
79 struct lm3630a_platform_data *pdata = pchip->pdata;
81 usleep_range(1000, 2000);
82 /* set Filter Strength Register */
83 rval = lm3630a_write(pchip, 0x50, 0x03);
84 /* set Cofig. register */
85 rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
86 /* set boost control */
87 rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
89 rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
91 rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
93 rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
94 rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
95 usleep_range(1000, 2000);
96 /* set brightness A and B */
97 rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
98 rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);
101 dev_err(pchip->dev, "i2c failed to access register\n");
105 /* interrupt handling */
106 static void lm3630a_delayed_func(struct work_struct *work)
109 struct lm3630a_chip *pchip;
111 pchip = container_of(work, struct lm3630a_chip, work.work);
113 rval = lm3630a_read(pchip, REG_INT_STATUS);
116 "i2c failed to access REG_INT_STATUS Register\n");
120 dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
123 static irqreturn_t lm3630a_isr_func(int irq, void *chip)
126 struct lm3630a_chip *pchip = chip;
127 unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
129 queue_delayed_work(pchip->irqthread, &pchip->work, delay);
131 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
133 dev_err(pchip->dev, "i2c failed to access register\n");
139 static int lm3630a_intr_config(struct lm3630a_chip *pchip)
143 rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
147 INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
148 pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
149 if (!pchip->irqthread) {
150 dev_err(pchip->dev, "create irq thread fail\n");
153 if (request_threaded_irq
154 (pchip->irq, NULL, lm3630a_isr_func,
155 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
156 dev_err(pchip->dev, "request threaded irq fail\n");
157 destroy_workqueue(pchip->irqthread);
163 static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
165 unsigned int period = pwm_get_period(pchip->pwmd);
166 unsigned int duty = br * period / br_max;
168 pwm_config(pchip->pwmd, duty, period);
170 pwm_enable(pchip->pwmd);
172 pwm_disable(pchip->pwmd);
175 /* update and get brightness */
176 static int lm3630a_bank_a_update_status(struct backlight_device *bl)
179 struct lm3630a_chip *pchip = bl_get_data(bl);
180 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
183 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
184 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
185 bl->props.max_brightness);
186 return bl->props.brightness;
190 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
193 usleep_range(1000, 2000);
194 /* minimum brightness is 0x04 */
195 ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
196 if (bl->props.brightness < 0x4)
197 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
199 ret |= lm3630a_update(pchip, REG_CTRL,
200 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
203 return bl->props.brightness;
206 dev_err(pchip->dev, "i2c failed to access\n");
207 return bl->props.brightness;
210 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
212 int brightness, rval;
213 struct lm3630a_chip *pchip = bl_get_data(bl);
214 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
216 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
217 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
220 brightness = (rval & 0x01) << 8;
221 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
229 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
232 usleep_range(1000, 2000);
233 rval = lm3630a_read(pchip, REG_BRT_A);
239 bl->props.brightness = brightness;
240 return bl->props.brightness;
242 dev_err(pchip->dev, "i2c failed to access register\n");
246 static const struct backlight_ops lm3630a_bank_a_ops = {
247 .options = BL_CORE_SUSPENDRESUME,
248 .update_status = lm3630a_bank_a_update_status,
249 .get_brightness = lm3630a_bank_a_get_brightness,
252 /* update and get brightness */
253 static int lm3630a_bank_b_update_status(struct backlight_device *bl)
256 struct lm3630a_chip *pchip = bl_get_data(bl);
257 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
260 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
261 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
262 bl->props.max_brightness);
263 return bl->props.brightness;
267 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
270 usleep_range(1000, 2000);
271 /* minimum brightness is 0x04 */
272 ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
273 if (bl->props.brightness < 0x4)
274 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
276 ret |= lm3630a_update(pchip, REG_CTRL,
277 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
280 return bl->props.brightness;
283 dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
284 return bl->props.brightness;
287 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
289 int brightness, rval;
290 struct lm3630a_chip *pchip = bl_get_data(bl);
291 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
293 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
294 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
297 brightness = (rval & 0x01) << 8;
298 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
306 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
309 usleep_range(1000, 2000);
310 rval = lm3630a_read(pchip, REG_BRT_B);
316 bl->props.brightness = brightness;
317 return bl->props.brightness;
319 dev_err(pchip->dev, "i2c failed to access register\n");
323 static const struct backlight_ops lm3630a_bank_b_ops = {
324 .options = BL_CORE_SUSPENDRESUME,
325 .update_status = lm3630a_bank_b_update_status,
326 .get_brightness = lm3630a_bank_b_get_brightness,
329 static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
331 struct backlight_properties props;
332 struct lm3630a_platform_data *pdata = pchip->pdata;
334 props.type = BACKLIGHT_RAW;
335 if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
336 props.brightness = pdata->leda_init_brt;
337 props.max_brightness = pdata->leda_max_brt;
339 devm_backlight_device_register(pchip->dev, "lm3630a_leda",
341 &lm3630a_bank_a_ops, &props);
342 if (IS_ERR(pchip->bleda))
343 return PTR_ERR(pchip->bleda);
346 if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
347 (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
348 props.brightness = pdata->ledb_init_brt;
349 props.max_brightness = pdata->ledb_max_brt;
351 devm_backlight_device_register(pchip->dev, "lm3630a_ledb",
353 &lm3630a_bank_b_ops, &props);
354 if (IS_ERR(pchip->bledb))
355 return PTR_ERR(pchip->bledb);
360 static const struct regmap_config lm3630a_regmap = {
363 .max_register = REG_MAX,
366 static int lm3630a_probe(struct i2c_client *client,
367 const struct i2c_device_id *id)
369 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
370 struct lm3630a_chip *pchip;
373 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
374 dev_err(&client->dev, "fail : i2c functionality check\n");
378 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
382 pchip->dev = &client->dev;
384 pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
385 if (IS_ERR(pchip->regmap)) {
386 rval = PTR_ERR(pchip->regmap);
387 dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
391 i2c_set_clientdata(client, pchip);
393 pdata = devm_kzalloc(pchip->dev,
394 sizeof(struct lm3630a_platform_data),
399 pdata->leda_ctrl = LM3630A_LEDA_ENABLE;
400 pdata->ledb_ctrl = LM3630A_LEDB_ENABLE;
401 pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
402 pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
403 pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
404 pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
406 pchip->pdata = pdata;
408 /* chip initialize */
409 rval = lm3630a_chip_init(pchip);
411 dev_err(&client->dev, "fail : init chip\n");
414 /* backlight register */
415 rval = lm3630a_backlight_register(pchip);
417 dev_err(&client->dev, "fail : backlight register.\n");
421 if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
422 pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
423 if (IS_ERR(pchip->pwmd)) {
424 dev_err(&client->dev, "fail : get pwm device\n");
425 return PTR_ERR(pchip->pwmd);
428 pchip->pwmd->period = pdata->pwm_period;
430 /* interrupt enable : irq 0 is not allowed */
431 pchip->irq = client->irq;
433 rval = lm3630a_intr_config(pchip);
437 dev_info(&client->dev, "LM3630A backlight register OK.\n");
441 static int lm3630a_remove(struct i2c_client *client)
444 struct lm3630a_chip *pchip = i2c_get_clientdata(client);
446 rval = lm3630a_write(pchip, REG_BRT_A, 0);
448 dev_err(pchip->dev, "i2c failed to access register\n");
450 rval = lm3630a_write(pchip, REG_BRT_B, 0);
452 dev_err(pchip->dev, "i2c failed to access register\n");
455 free_irq(pchip->irq, pchip);
456 flush_workqueue(pchip->irqthread);
457 destroy_workqueue(pchip->irqthread);
462 static const struct i2c_device_id lm3630a_id[] = {
467 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
469 static struct i2c_driver lm3630a_i2c_driver = {
471 .name = LM3630A_NAME,
473 .probe = lm3630a_probe,
474 .remove = lm3630a_remove,
475 .id_table = lm3630a_id,
478 module_i2c_driver(lm3630a_i2c_driver);
480 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
483 MODULE_LICENSE("GPL v2");