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/pwm.h>
16 #include <linux/platform_data/lm3630a_bl.h>
19 #define REG_BOOST 0x02
20 #define REG_CONFIG 0x01
21 #define REG_BRT_A 0x03
22 #define REG_BRT_B 0x04
25 #define REG_INT_STATUS 0x09
26 #define REG_INT_EN 0x0A
27 #define REG_FAULT 0x0B
28 #define REG_PWM_OUTLOW 0x12
29 #define REG_PWM_OUTHIGH 0x13
30 #define REG_FILTER_STRENGTH 0x50
33 #define INT_DEBOUNCE_MSEC 10
35 #define LM3630A_BANK_0 0
36 #define LM3630A_BANK_1 1
38 #define LM3630A_NUM_SINKS 2
39 #define LM3630A_SINK_0 0
40 #define LM3630A_SINK_1 1
44 struct delayed_work work;
47 struct workqueue_struct *irqthread;
48 struct lm3630a_platform_data *pdata;
49 struct backlight_device *bleda;
50 struct backlight_device *bledb;
51 struct regmap *regmap;
52 struct pwm_device *pwmd;
56 static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
61 rval = regmap_read(pchip->regmap, reg, ®_val);
64 return reg_val & 0xFF;
67 static int lm3630a_write(struct lm3630a_chip *pchip,
68 unsigned int reg, unsigned int data)
70 return regmap_write(pchip->regmap, reg, data);
73 static int lm3630a_update(struct lm3630a_chip *pchip,
74 unsigned int reg, unsigned int mask,
77 return regmap_update_bits(pchip->regmap, reg, mask, data);
81 static int lm3630a_chip_init(struct lm3630a_chip *pchip)
84 struct lm3630a_platform_data *pdata = pchip->pdata;
86 usleep_range(1000, 2000);
87 /* set Filter Strength Register */
88 rval = lm3630a_write(pchip, REG_FILTER_STRENGTH, 0x03);
89 /* set Cofig. register */
90 rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
91 /* set boost control */
92 rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
94 rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
96 rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
98 rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
99 rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
100 usleep_range(1000, 2000);
101 /* set brightness A and B */
102 rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
103 rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);
106 dev_err(pchip->dev, "i2c failed to access register\n");
110 /* interrupt handling */
111 static void lm3630a_delayed_func(struct work_struct *work)
114 struct lm3630a_chip *pchip;
116 pchip = container_of(work, struct lm3630a_chip, work.work);
118 rval = lm3630a_read(pchip, REG_INT_STATUS);
121 "i2c failed to access REG_INT_STATUS Register\n");
125 dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
128 static irqreturn_t lm3630a_isr_func(int irq, void *chip)
131 struct lm3630a_chip *pchip = chip;
132 unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
134 queue_delayed_work(pchip->irqthread, &pchip->work, delay);
136 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
138 dev_err(pchip->dev, "i2c failed to access register\n");
144 static int lm3630a_intr_config(struct lm3630a_chip *pchip)
148 rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
152 INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
153 pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
154 if (!pchip->irqthread) {
155 dev_err(pchip->dev, "create irq thread fail\n");
158 if (request_threaded_irq
159 (pchip->irq, NULL, lm3630a_isr_func,
160 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
161 dev_err(pchip->dev, "request threaded irq fail\n");
162 destroy_workqueue(pchip->irqthread);
168 static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
170 unsigned int period = pchip->pdata->pwm_period;
171 unsigned int duty = br * period / br_max;
173 pwm_config(pchip->pwmd, duty, period);
175 pwm_enable(pchip->pwmd);
177 pwm_disable(pchip->pwmd);
180 /* update and get brightness */
181 static int lm3630a_bank_a_update_status(struct backlight_device *bl)
184 struct lm3630a_chip *pchip = bl_get_data(bl);
185 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
188 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
189 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
190 bl->props.max_brightness);
191 return bl->props.brightness;
195 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
198 usleep_range(1000, 2000);
199 /* minimum brightness is 0x04 */
200 ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
201 if (bl->props.brightness < 0x4)
202 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
204 ret |= lm3630a_update(pchip, REG_CTRL,
205 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
211 dev_err(pchip->dev, "i2c failed to access\n");
212 return bl->props.brightness;
215 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
217 int brightness, rval;
218 struct lm3630a_chip *pchip = bl_get_data(bl);
219 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
221 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
222 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
225 brightness = (rval & 0x01) << 8;
226 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
234 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
237 usleep_range(1000, 2000);
238 rval = lm3630a_read(pchip, REG_BRT_A);
244 bl->props.brightness = brightness;
245 return bl->props.brightness;
247 dev_err(pchip->dev, "i2c failed to access register\n");
251 static const struct backlight_ops lm3630a_bank_a_ops = {
252 .options = BL_CORE_SUSPENDRESUME,
253 .update_status = lm3630a_bank_a_update_status,
254 .get_brightness = lm3630a_bank_a_get_brightness,
257 /* update and get brightness */
258 static int lm3630a_bank_b_update_status(struct backlight_device *bl)
261 struct lm3630a_chip *pchip = bl_get_data(bl);
262 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
265 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
266 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
267 bl->props.max_brightness);
268 return bl->props.brightness;
272 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
275 usleep_range(1000, 2000);
276 /* minimum brightness is 0x04 */
277 ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
278 if (bl->props.brightness < 0x4)
279 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
281 ret |= lm3630a_update(pchip, REG_CTRL,
282 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
288 dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
289 return bl->props.brightness;
292 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
294 int brightness, rval;
295 struct lm3630a_chip *pchip = bl_get_data(bl);
296 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
298 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
299 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
302 brightness = (rval & 0x01) << 8;
303 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
311 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
314 usleep_range(1000, 2000);
315 rval = lm3630a_read(pchip, REG_BRT_B);
321 bl->props.brightness = brightness;
322 return bl->props.brightness;
324 dev_err(pchip->dev, "i2c failed to access register\n");
328 static const struct backlight_ops lm3630a_bank_b_ops = {
329 .options = BL_CORE_SUSPENDRESUME,
330 .update_status = lm3630a_bank_b_update_status,
331 .get_brightness = lm3630a_bank_b_get_brightness,
334 static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
336 struct lm3630a_platform_data *pdata = pchip->pdata;
337 struct backlight_properties props;
340 props.type = BACKLIGHT_RAW;
341 if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
342 props.brightness = pdata->leda_init_brt;
343 props.max_brightness = pdata->leda_max_brt;
344 label = pdata->leda_label ? pdata->leda_label : "lm3630a_leda";
346 devm_backlight_device_register(pchip->dev, label,
348 &lm3630a_bank_a_ops, &props);
349 if (IS_ERR(pchip->bleda))
350 return PTR_ERR(pchip->bleda);
353 if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
354 (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
355 props.brightness = pdata->ledb_init_brt;
356 props.max_brightness = pdata->ledb_max_brt;
357 label = pdata->ledb_label ? pdata->ledb_label : "lm3630a_ledb";
359 devm_backlight_device_register(pchip->dev, label,
361 &lm3630a_bank_b_ops, &props);
362 if (IS_ERR(pchip->bledb))
363 return PTR_ERR(pchip->bledb);
368 static const struct regmap_config lm3630a_regmap = {
371 .max_register = REG_MAX,
374 static int lm3630a_parse_led_sources(struct fwnode_handle *node,
375 int default_led_sources)
377 u32 sources[LM3630A_NUM_SINKS];
378 int ret, num_sources, i;
380 num_sources = fwnode_property_count_u32(node, "led-sources");
382 return default_led_sources;
383 else if (num_sources > ARRAY_SIZE(sources))
386 ret = fwnode_property_read_u32_array(node, "led-sources", sources,
391 for (i = 0; i < num_sources; i++) {
392 if (sources[i] < LM3630A_SINK_0 || sources[i] > LM3630A_SINK_1)
395 ret |= BIT(sources[i]);
401 static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
402 struct fwnode_handle *node, int *seen_led_sources)
404 int led_sources, ret;
409 ret = fwnode_property_read_u32(node, "reg", &bank);
413 if (bank < LM3630A_BANK_0 || bank > LM3630A_BANK_1)
416 led_sources = lm3630a_parse_led_sources(node, BIT(bank));
420 if (*seen_led_sources & led_sources)
423 *seen_led_sources |= led_sources;
425 linear = fwnode_property_read_bool(node,
426 "ti,linear-mapping-mode");
428 if (led_sources & BIT(LM3630A_SINK_0) ||
429 !(led_sources & BIT(LM3630A_SINK_1)))
432 pdata->ledb_ctrl = linear ?
433 LM3630A_LEDB_ENABLE_LINEAR :
436 if (!(led_sources & BIT(LM3630A_SINK_0)))
439 pdata->leda_ctrl = linear ?
440 LM3630A_LEDA_ENABLE_LINEAR :
443 if (led_sources & BIT(LM3630A_SINK_1))
444 pdata->ledb_ctrl = LM3630A_LEDB_ON_A;
447 ret = fwnode_property_read_string(node, "label", &label);
450 pdata->ledb_label = label;
452 pdata->leda_label = label;
455 ret = fwnode_property_read_u32(node, "default-brightness",
459 pdata->ledb_init_brt = val;
461 pdata->leda_init_brt = val;
464 ret = fwnode_property_read_u32(node, "max-brightness", &val);
467 pdata->ledb_max_brt = val;
469 pdata->leda_max_brt = val;
475 static int lm3630a_parse_node(struct lm3630a_chip *pchip,
476 struct lm3630a_platform_data *pdata)
478 int ret = -ENODEV, seen_led_sources = 0;
479 struct fwnode_handle *node;
481 device_for_each_child_node(pchip->dev, node) {
482 ret = lm3630a_parse_bank(pdata, node, &seen_led_sources);
490 static int lm3630a_probe(struct i2c_client *client,
491 const struct i2c_device_id *id)
493 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
494 struct lm3630a_chip *pchip;
497 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
498 dev_err(&client->dev, "fail : i2c functionality check\n");
502 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
506 pchip->dev = &client->dev;
508 pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
509 if (IS_ERR(pchip->regmap)) {
510 rval = PTR_ERR(pchip->regmap);
511 dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
515 i2c_set_clientdata(client, pchip);
517 pdata = devm_kzalloc(pchip->dev,
518 sizeof(struct lm3630a_platform_data),
524 pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
525 pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
526 pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
527 pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
529 rval = lm3630a_parse_node(pchip, pdata);
531 dev_err(&client->dev, "fail : parse node\n");
535 pchip->pdata = pdata;
537 /* chip initialize */
538 rval = lm3630a_chip_init(pchip);
540 dev_err(&client->dev, "fail : init chip\n");
543 /* backlight register */
544 rval = lm3630a_backlight_register(pchip);
546 dev_err(&client->dev, "fail : backlight register.\n");
550 if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
551 pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
552 if (IS_ERR(pchip->pwmd)) {
553 dev_err(&client->dev, "fail : get pwm device\n");
554 return PTR_ERR(pchip->pwmd);
558 * FIXME: pwm_apply_args() should be removed when switching to
559 * the atomic PWM API.
561 pwm_apply_args(pchip->pwmd);
564 /* interrupt enable : irq 0 is not allowed */
565 pchip->irq = client->irq;
567 rval = lm3630a_intr_config(pchip);
571 dev_info(&client->dev, "LM3630A backlight register OK.\n");
575 static int lm3630a_remove(struct i2c_client *client)
578 struct lm3630a_chip *pchip = i2c_get_clientdata(client);
580 rval = lm3630a_write(pchip, REG_BRT_A, 0);
582 dev_err(pchip->dev, "i2c failed to access register\n");
584 rval = lm3630a_write(pchip, REG_BRT_B, 0);
586 dev_err(pchip->dev, "i2c failed to access register\n");
589 free_irq(pchip->irq, pchip);
590 flush_workqueue(pchip->irqthread);
591 destroy_workqueue(pchip->irqthread);
596 static const struct i2c_device_id lm3630a_id[] = {
601 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
603 static const struct of_device_id lm3630a_match_table[] = {
604 { .compatible = "ti,lm3630a", },
608 MODULE_DEVICE_TABLE(of, lm3630a_match_table);
610 static struct i2c_driver lm3630a_i2c_driver = {
612 .name = LM3630A_NAME,
613 .of_match_table = lm3630a_match_table,
615 .probe = lm3630a_probe,
616 .remove = lm3630a_remove,
617 .id_table = lm3630a_id,
620 module_i2c_driver(lm3630a_i2c_driver);
622 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
623 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
624 MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
625 MODULE_LICENSE("GPL v2");