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;
55 struct pwm_state pwmd_state;
59 static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
64 rval = regmap_read(pchip->regmap, reg, ®_val);
67 return reg_val & 0xFF;
70 static int lm3630a_write(struct lm3630a_chip *pchip,
71 unsigned int reg, unsigned int data)
73 return regmap_write(pchip->regmap, reg, data);
76 static int lm3630a_update(struct lm3630a_chip *pchip,
77 unsigned int reg, unsigned int mask,
80 return regmap_update_bits(pchip->regmap, reg, mask, data);
84 static int lm3630a_chip_init(struct lm3630a_chip *pchip)
87 struct lm3630a_platform_data *pdata = pchip->pdata;
89 usleep_range(1000, 2000);
90 /* set Filter Strength Register */
91 rval = lm3630a_write(pchip, REG_FILTER_STRENGTH, 0x03);
92 /* set Cofig. register */
93 rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
94 /* set boost control */
95 rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
97 rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
99 rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
101 rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
102 rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
103 usleep_range(1000, 2000);
104 /* set brightness A and B */
105 rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
106 rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);
109 dev_err(pchip->dev, "i2c failed to access register\n");
113 /* interrupt handling */
114 static void lm3630a_delayed_func(struct work_struct *work)
117 struct lm3630a_chip *pchip;
119 pchip = container_of(work, struct lm3630a_chip, work.work);
121 rval = lm3630a_read(pchip, REG_INT_STATUS);
124 "i2c failed to access REG_INT_STATUS Register\n");
128 dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
131 static irqreturn_t lm3630a_isr_func(int irq, void *chip)
134 struct lm3630a_chip *pchip = chip;
135 unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
137 queue_delayed_work(pchip->irqthread, &pchip->work, delay);
139 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
141 dev_err(pchip->dev, "i2c failed to access register\n");
147 static int lm3630a_intr_config(struct lm3630a_chip *pchip)
151 rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
155 INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
156 pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
157 if (!pchip->irqthread) {
158 dev_err(pchip->dev, "create irq thread fail\n");
161 if (request_threaded_irq
162 (pchip->irq, NULL, lm3630a_isr_func,
163 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
164 dev_err(pchip->dev, "request threaded irq fail\n");
165 destroy_workqueue(pchip->irqthread);
171 static int lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
175 pchip->pwmd_state.period = pchip->pdata->pwm_period;
177 err = pwm_set_relative_duty_cycle(&pchip->pwmd_state, br, br_max);
181 pchip->pwmd_state.enabled = pchip->pwmd_state.duty_cycle ? true : false;
183 return pwm_apply_might_sleep(pchip->pwmd, &pchip->pwmd_state);
186 /* update and get brightness */
187 static int lm3630a_bank_a_update_status(struct backlight_device *bl)
190 struct lm3630a_chip *pchip = bl_get_data(bl);
191 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
192 int brightness = backlight_get_brightness(bl);
195 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0)
196 return lm3630a_pwm_ctrl(pchip, brightness,
197 bl->props.max_brightness);
200 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
203 usleep_range(1000, 2000);
204 /* minimum brightness is 0x04 */
205 ret = lm3630a_write(pchip, REG_BRT_A, brightness);
207 if (brightness < 0x4)
208 /* turn the string off */
209 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
211 ret |= lm3630a_update(pchip, REG_CTRL,
212 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
218 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
222 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
224 int brightness, rval;
225 struct lm3630a_chip *pchip = bl_get_data(bl);
226 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
228 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
229 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
232 brightness = (rval & 0x01) << 8;
233 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
241 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
244 usleep_range(1000, 2000);
245 rval = lm3630a_read(pchip, REG_BRT_A);
251 dev_err(pchip->dev, "i2c failed to access register\n");
255 static const struct backlight_ops lm3630a_bank_a_ops = {
256 .options = BL_CORE_SUSPENDRESUME,
257 .update_status = lm3630a_bank_a_update_status,
258 .get_brightness = lm3630a_bank_a_get_brightness,
261 /* update and get brightness */
262 static int lm3630a_bank_b_update_status(struct backlight_device *bl)
265 struct lm3630a_chip *pchip = bl_get_data(bl);
266 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
267 int brightness = backlight_get_brightness(bl);
270 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0)
271 return lm3630a_pwm_ctrl(pchip, brightness,
272 bl->props.max_brightness);
275 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
278 usleep_range(1000, 2000);
279 /* minimum brightness is 0x04 */
280 ret = lm3630a_write(pchip, REG_BRT_B, brightness);
282 if (brightness < 0x4)
283 /* turn the string off */
284 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
286 ret |= lm3630a_update(pchip, REG_CTRL,
287 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
293 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
297 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
299 int brightness, rval;
300 struct lm3630a_chip *pchip = bl_get_data(bl);
301 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
303 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
304 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
307 brightness = (rval & 0x01) << 8;
308 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
316 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
319 usleep_range(1000, 2000);
320 rval = lm3630a_read(pchip, REG_BRT_B);
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 memset(&props, 0, sizeof(struct backlight_properties));
343 props.type = BACKLIGHT_RAW;
344 if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
345 props.brightness = pdata->leda_init_brt;
346 props.max_brightness = pdata->leda_max_brt;
347 label = pdata->leda_label ? pdata->leda_label : "lm3630a_leda";
349 devm_backlight_device_register(pchip->dev, label,
351 &lm3630a_bank_a_ops, &props);
352 if (IS_ERR(pchip->bleda))
353 return PTR_ERR(pchip->bleda);
356 if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
357 (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
358 props.brightness = pdata->ledb_init_brt;
359 props.max_brightness = pdata->ledb_max_brt;
360 label = pdata->ledb_label ? pdata->ledb_label : "lm3630a_ledb";
362 devm_backlight_device_register(pchip->dev, label,
364 &lm3630a_bank_b_ops, &props);
365 if (IS_ERR(pchip->bledb))
366 return PTR_ERR(pchip->bledb);
371 static const struct regmap_config lm3630a_regmap = {
374 .max_register = REG_MAX,
377 static int lm3630a_parse_led_sources(struct fwnode_handle *node,
378 int default_led_sources)
380 u32 sources[LM3630A_NUM_SINKS];
381 int ret, num_sources, i;
383 num_sources = fwnode_property_count_u32(node, "led-sources");
385 return default_led_sources;
386 else if (num_sources > ARRAY_SIZE(sources))
389 ret = fwnode_property_read_u32_array(node, "led-sources", sources,
394 for (i = 0; i < num_sources; i++) {
395 if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1)
398 ret |= BIT(sources[i]);
404 static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
405 struct fwnode_handle *node, int *seen_led_sources)
407 int led_sources, ret;
412 ret = fwnode_property_read_u32(node, "reg", &bank);
416 if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1)
419 led_sources = lm3630a_parse_led_sources(node, BIT(bank));
423 if (*seen_led_sources & led_sources)
426 *seen_led_sources |= led_sources;
428 linear = fwnode_property_read_bool(node,
429 "ti,linear-mapping-mode");
431 if (led_sources & BIT(LM3630A_SINK_0) ||
432 !(led_sources & BIT(LM3630A_SINK_1)))
435 pdata->ledb_ctrl = linear ?
436 LM3630A_LEDB_ENABLE_LINEAR :
439 if (!(led_sources & BIT(LM3630A_SINK_0)))
442 pdata->leda_ctrl = linear ?
443 LM3630A_LEDA_ENABLE_LINEAR :
446 if (led_sources & BIT(LM3630A_SINK_1))
447 pdata->ledb_ctrl = LM3630A_LEDB_ON_A;
450 ret = fwnode_property_read_string(node, "label", &label);
453 pdata->ledb_label = label;
455 pdata->leda_label = label;
458 ret = fwnode_property_read_u32(node, "default-brightness",
462 pdata->ledb_init_brt = val;
464 pdata->leda_init_brt = val;
467 ret = fwnode_property_read_u32(node, "max-brightness", &val);
470 pdata->ledb_max_brt = val;
472 pdata->leda_max_brt = val;
478 static int lm3630a_parse_node(struct lm3630a_chip *pchip,
479 struct lm3630a_platform_data *pdata)
481 int ret = -ENODEV, seen_led_sources = 0;
482 struct fwnode_handle *node;
484 device_for_each_child_node(pchip->dev, node) {
485 ret = lm3630a_parse_bank(pdata, node, &seen_led_sources);
487 fwnode_handle_put(node);
495 static int lm3630a_probe(struct i2c_client *client)
497 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
498 struct lm3630a_chip *pchip;
501 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
502 dev_err(&client->dev, "fail : i2c functionality check\n");
506 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
510 pchip->dev = &client->dev;
512 pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
513 if (IS_ERR(pchip->regmap)) {
514 rval = PTR_ERR(pchip->regmap);
515 dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
519 i2c_set_clientdata(client, pchip);
521 pdata = devm_kzalloc(pchip->dev,
522 sizeof(struct lm3630a_platform_data),
528 pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
529 pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
530 pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
531 pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
533 rval = lm3630a_parse_node(pchip, pdata);
535 dev_err(&client->dev, "fail : parse node\n");
539 pchip->pdata = pdata;
541 pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
543 if (IS_ERR(pchip->enable_gpio))
544 return 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 return dev_err_probe(&client->dev, PTR_ERR(pchip->pwmd),
563 "fail : get pwm device\n");
565 pwm_init_state(pchip->pwmd, &pchip->pwmd_state);
568 /* interrupt enable : irq 0 is not allowed */
569 pchip->irq = client->irq;
571 rval = lm3630a_intr_config(pchip);
575 dev_info(&client->dev, "LM3630A backlight register OK.\n");
579 static void lm3630a_remove(struct i2c_client *client)
582 struct lm3630a_chip *pchip = i2c_get_clientdata(client);
584 rval = lm3630a_write(pchip, REG_BRT_A, 0);
586 dev_err(pchip->dev, "i2c failed to access register\n");
588 rval = lm3630a_write(pchip, REG_BRT_B, 0);
590 dev_err(pchip->dev, "i2c failed to access register\n");
593 free_irq(pchip->irq, pchip);
594 destroy_workqueue(pchip->irqthread);
598 static const struct i2c_device_id lm3630a_id[] = {
603 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
605 static const struct of_device_id lm3630a_match_table[] = {
606 { .compatible = "ti,lm3630a", },
610 MODULE_DEVICE_TABLE(of, lm3630a_match_table);
612 static struct i2c_driver lm3630a_i2c_driver = {
614 .name = LM3630A_NAME,
615 .of_match_table = lm3630a_match_table,
617 .probe = lm3630a_probe,
618 .remove = lm3630a_remove,
619 .id_table = lm3630a_id,
622 module_i2c_driver(lm3630a_i2c_driver);
624 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
627 MODULE_LICENSE("GPL v2");