1 // SPDX-License-Identifier: GPL-2.0-only
3 * Simple driver for Texas Instruments LM3630A Backlight driver chip
4 * Copyright (C) 2012 Texas Instruments
6 #include <linux/module.h>
7 #include <linux/slab.h>
9 #include <linux/backlight.h>
10 #include <linux/err.h>
11 #include <linux/delay.h>
12 #include <linux/uaccess.h>
13 #include <linux/interrupt.h>
14 #include <linux/regmap.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/pwm.h>
17 #include <linux/platform_data/lm3630a_bl.h>
20 #define REG_BOOST 0x02
21 #define REG_CONFIG 0x01
22 #define REG_BRT_A 0x03
23 #define REG_BRT_B 0x04
26 #define REG_INT_STATUS 0x09
27 #define REG_INT_EN 0x0A
28 #define REG_FAULT 0x0B
29 #define REG_PWM_OUTLOW 0x12
30 #define REG_PWM_OUTHIGH 0x13
31 #define REG_FILTER_STRENGTH 0x50
34 #define INT_DEBOUNCE_MSEC 10
36 #define LM3630A_BANK_0 0
37 #define LM3630A_BANK_1 1
39 #define LM3630A_NUM_SINKS 2
40 #define LM3630A_SINK_0 0
41 #define LM3630A_SINK_1 1
45 struct delayed_work work;
48 struct workqueue_struct *irqthread;
49 struct lm3630a_platform_data *pdata;
50 struct backlight_device *bleda;
51 struct backlight_device *bledb;
52 struct gpio_desc *enable_gpio;
53 struct regmap *regmap;
54 struct pwm_device *pwmd;
58 static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
63 rval = regmap_read(pchip->regmap, reg, ®_val);
66 return reg_val & 0xFF;
69 static int lm3630a_write(struct lm3630a_chip *pchip,
70 unsigned int reg, unsigned int data)
72 return regmap_write(pchip->regmap, reg, data);
75 static int lm3630a_update(struct lm3630a_chip *pchip,
76 unsigned int reg, unsigned int mask,
79 return regmap_update_bits(pchip->regmap, reg, mask, data);
83 static int lm3630a_chip_init(struct lm3630a_chip *pchip)
86 struct lm3630a_platform_data *pdata = pchip->pdata;
88 usleep_range(1000, 2000);
89 /* set Filter Strength Register */
90 rval = lm3630a_write(pchip, REG_FILTER_STRENGTH, 0x03);
91 /* set Cofig. register */
92 rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
93 /* set boost control */
94 rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
96 rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
98 rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
100 rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
101 rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
102 usleep_range(1000, 2000);
103 /* set brightness A and B */
104 rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
105 rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);
108 dev_err(pchip->dev, "i2c failed to access register\n");
112 /* interrupt handling */
113 static void lm3630a_delayed_func(struct work_struct *work)
116 struct lm3630a_chip *pchip;
118 pchip = container_of(work, struct lm3630a_chip, work.work);
120 rval = lm3630a_read(pchip, REG_INT_STATUS);
123 "i2c failed to access REG_INT_STATUS Register\n");
127 dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
130 static irqreturn_t lm3630a_isr_func(int irq, void *chip)
133 struct lm3630a_chip *pchip = chip;
134 unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
136 queue_delayed_work(pchip->irqthread, &pchip->work, delay);
138 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
140 dev_err(pchip->dev, "i2c failed to access register\n");
146 static int lm3630a_intr_config(struct lm3630a_chip *pchip)
150 rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
154 INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
155 pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
156 if (!pchip->irqthread) {
157 dev_err(pchip->dev, "create irq thread fail\n");
160 if (request_threaded_irq
161 (pchip->irq, NULL, lm3630a_isr_func,
162 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
163 dev_err(pchip->dev, "request threaded irq fail\n");
164 destroy_workqueue(pchip->irqthread);
170 static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
172 unsigned int period = pchip->pdata->pwm_period;
173 unsigned int duty = br * period / br_max;
175 pwm_config(pchip->pwmd, duty, period);
177 pwm_enable(pchip->pwmd);
179 pwm_disable(pchip->pwmd);
182 /* update and get brightness */
183 static int lm3630a_bank_a_update_status(struct backlight_device *bl)
186 struct lm3630a_chip *pchip = bl_get_data(bl);
187 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
190 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
191 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
192 bl->props.max_brightness);
193 return bl->props.brightness;
197 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
200 usleep_range(1000, 2000);
201 /* minimum brightness is 0x04 */
202 ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
203 if (bl->props.brightness < 0x4)
204 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
206 ret |= lm3630a_update(pchip, REG_CTRL,
207 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
213 dev_err(pchip->dev, "i2c failed to access\n");
214 return bl->props.brightness;
217 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
219 int brightness, rval;
220 struct lm3630a_chip *pchip = bl_get_data(bl);
221 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
223 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
224 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
227 brightness = (rval & 0x01) << 8;
228 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
236 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
239 usleep_range(1000, 2000);
240 rval = lm3630a_read(pchip, REG_BRT_A);
246 bl->props.brightness = brightness;
247 return bl->props.brightness;
249 dev_err(pchip->dev, "i2c failed to access register\n");
253 static const struct backlight_ops lm3630a_bank_a_ops = {
254 .options = BL_CORE_SUSPENDRESUME,
255 .update_status = lm3630a_bank_a_update_status,
256 .get_brightness = lm3630a_bank_a_get_brightness,
259 /* update and get brightness */
260 static int lm3630a_bank_b_update_status(struct backlight_device *bl)
263 struct lm3630a_chip *pchip = bl_get_data(bl);
264 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
267 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
268 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
269 bl->props.max_brightness);
270 return bl->props.brightness;
274 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
277 usleep_range(1000, 2000);
278 /* minimum brightness is 0x04 */
279 ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
280 if (bl->props.brightness < 0x4)
281 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
283 ret |= lm3630a_update(pchip, REG_CTRL,
284 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
290 dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
291 return bl->props.brightness;
294 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
296 int brightness, rval;
297 struct lm3630a_chip *pchip = bl_get_data(bl);
298 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
300 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
301 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
304 brightness = (rval & 0x01) << 8;
305 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
313 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
316 usleep_range(1000, 2000);
317 rval = lm3630a_read(pchip, REG_BRT_B);
323 bl->props.brightness = brightness;
324 return bl->props.brightness;
326 dev_err(pchip->dev, "i2c failed to access register\n");
330 static const struct backlight_ops lm3630a_bank_b_ops = {
331 .options = BL_CORE_SUSPENDRESUME,
332 .update_status = lm3630a_bank_b_update_status,
333 .get_brightness = lm3630a_bank_b_get_brightness,
336 static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
338 struct lm3630a_platform_data *pdata = pchip->pdata;
339 struct backlight_properties props;
342 props.type = BACKLIGHT_RAW;
343 if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
344 props.brightness = pdata->leda_init_brt;
345 props.max_brightness = pdata->leda_max_brt;
346 label = pdata->leda_label ? pdata->leda_label : "lm3630a_leda";
348 devm_backlight_device_register(pchip->dev, label,
350 &lm3630a_bank_a_ops, &props);
351 if (IS_ERR(pchip->bleda))
352 return PTR_ERR(pchip->bleda);
355 if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
356 (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
357 props.brightness = pdata->ledb_init_brt;
358 props.max_brightness = pdata->ledb_max_brt;
359 label = pdata->ledb_label ? pdata->ledb_label : "lm3630a_ledb";
361 devm_backlight_device_register(pchip->dev, label,
363 &lm3630a_bank_b_ops, &props);
364 if (IS_ERR(pchip->bledb))
365 return PTR_ERR(pchip->bledb);
370 static const struct regmap_config lm3630a_regmap = {
373 .max_register = REG_MAX,
376 static int lm3630a_parse_led_sources(struct fwnode_handle *node,
377 int default_led_sources)
379 u32 sources[LM3630A_NUM_SINKS];
380 int ret, num_sources, i;
382 num_sources = fwnode_property_count_u32(node, "led-sources");
384 return default_led_sources;
385 else if (num_sources > ARRAY_SIZE(sources))
388 ret = fwnode_property_read_u32_array(node, "led-sources", sources,
393 for (i = 0; i < num_sources; i++) {
394 if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1)
397 ret |= BIT(sources[i]);
403 static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
404 struct fwnode_handle *node, int *seen_led_sources)
406 int led_sources, ret;
411 ret = fwnode_property_read_u32(node, "reg", &bank);
415 if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1)
418 led_sources = lm3630a_parse_led_sources(node, BIT(bank));
422 if (*seen_led_sources & led_sources)
425 *seen_led_sources |= led_sources;
427 linear = fwnode_property_read_bool(node,
428 "ti,linear-mapping-mode");
430 if (led_sources & BIT(LM3630A_SINK_0) ||
431 !(led_sources & BIT(LM3630A_SINK_1)))
434 pdata->ledb_ctrl = linear ?
435 LM3630A_LEDB_ENABLE_LINEAR :
438 if (!(led_sources & BIT(LM3630A_SINK_0)))
441 pdata->leda_ctrl = linear ?
442 LM3630A_LEDA_ENABLE_LINEAR :
445 if (led_sources & BIT(LM3630A_SINK_1))
446 pdata->ledb_ctrl = LM3630A_LEDB_ON_A;
449 ret = fwnode_property_read_string(node, "label", &label);
452 pdata->ledb_label = label;
454 pdata->leda_label = label;
457 ret = fwnode_property_read_u32(node, "default-brightness",
461 pdata->ledb_init_brt = val;
463 pdata->leda_init_brt = val;
466 ret = fwnode_property_read_u32(node, "max-brightness", &val);
469 pdata->ledb_max_brt = val;
471 pdata->leda_max_brt = val;
477 static int lm3630a_parse_node(struct lm3630a_chip *pchip,
478 struct lm3630a_platform_data *pdata)
480 int ret = -ENODEV, seen_led_sources = 0;
481 struct fwnode_handle *node;
483 device_for_each_child_node(pchip->dev, node) {
484 ret = lm3630a_parse_bank(pdata, node, &seen_led_sources);
492 static int lm3630a_probe(struct i2c_client *client,
493 const struct i2c_device_id *id)
495 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
496 struct lm3630a_chip *pchip;
499 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
500 dev_err(&client->dev, "fail : i2c functionality check\n");
504 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
508 pchip->dev = &client->dev;
510 pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
511 if (IS_ERR(pchip->regmap)) {
512 rval = PTR_ERR(pchip->regmap);
513 dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
517 i2c_set_clientdata(client, pchip);
519 pdata = devm_kzalloc(pchip->dev,
520 sizeof(struct lm3630a_platform_data),
526 pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
527 pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
528 pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
529 pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
531 rval = lm3630a_parse_node(pchip, pdata);
533 dev_err(&client->dev, "fail : parse node\n");
537 pchip->pdata = pdata;
539 pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
541 if (IS_ERR(pchip->enable_gpio)) {
542 rval = PTR_ERR(pchip->enable_gpio);
546 /* chip initialize */
547 rval = lm3630a_chip_init(pchip);
549 dev_err(&client->dev, "fail : init chip\n");
552 /* backlight register */
553 rval = lm3630a_backlight_register(pchip);
555 dev_err(&client->dev, "fail : backlight register.\n");
559 if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
560 pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
561 if (IS_ERR(pchip->pwmd)) {
562 dev_err(&client->dev, "fail : get pwm device\n");
563 return PTR_ERR(pchip->pwmd);
567 * FIXME: pwm_apply_args() should be removed when switching to
568 * the atomic PWM API.
570 pwm_apply_args(pchip->pwmd);
573 /* interrupt enable : irq 0 is not allowed */
574 pchip->irq = client->irq;
576 rval = lm3630a_intr_config(pchip);
580 dev_info(&client->dev, "LM3630A backlight register OK.\n");
584 static int lm3630a_remove(struct i2c_client *client)
587 struct lm3630a_chip *pchip = i2c_get_clientdata(client);
589 rval = lm3630a_write(pchip, REG_BRT_A, 0);
591 dev_err(pchip->dev, "i2c failed to access register\n");
593 rval = lm3630a_write(pchip, REG_BRT_B, 0);
595 dev_err(pchip->dev, "i2c failed to access register\n");
598 free_irq(pchip->irq, pchip);
599 flush_workqueue(pchip->irqthread);
600 destroy_workqueue(pchip->irqthread);
605 static const struct i2c_device_id lm3630a_id[] = {
610 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
612 static const struct of_device_id lm3630a_match_table[] = {
613 { .compatible = "ti,lm3630a", },
617 MODULE_DEVICE_TABLE(of, lm3630a_match_table);
619 static struct i2c_driver lm3630a_i2c_driver = {
621 .name = LM3630A_NAME,
622 .of_match_table = lm3630a_match_table,
624 .probe = lm3630a_probe,
625 .remove = lm3630a_remove,
626 .id_table = lm3630a_id,
629 module_i2c_driver(lm3630a_i2c_driver);
631 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
632 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
633 MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
634 MODULE_LICENSE("GPL v2");