1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Simple driver for Texas Instruments LM3630A Backlight driver chip
4 * Copyright (C) 2012 Texas Instruments
5 */
6 #include <linux/module.h>
7 #include <linux/slab.h>
8 #include <linux/i2c.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>
18
19 #define REG_CTRL 0x00
20 #define REG_BOOST 0x02
21 #define REG_CONFIG 0x01
22 #define REG_BRT_A 0x03
23 #define REG_BRT_B 0x04
24 #define REG_I_A 0x05
25 #define REG_I_B 0x06
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
32 #define REG_MAX 0x50
33
34 #define INT_DEBOUNCE_MSEC 10
35
36 #define LM3630A_BANK_0 0
37 #define LM3630A_BANK_1 1
38
39 #define LM3630A_NUM_SINKS 2
40 #define LM3630A_SINK_0 0
41 #define LM3630A_SINK_1 1
42
43 struct lm3630a_chip {
44 struct device *dev;
45 struct delayed_work work;
46
47 int irq;
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;
56 };
57
58 /* i2c access */
lm3630a_read(struct lm3630a_chip * pchip,unsigned int reg)59 static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
60 {
61 int rval;
62 unsigned int reg_val;
63
64 rval = regmap_read(pchip->regmap, reg, ®_val);
65 if (rval < 0)
66 return rval;
67 return reg_val & 0xFF;
68 }
69
lm3630a_write(struct lm3630a_chip * pchip,unsigned int reg,unsigned int data)70 static int lm3630a_write(struct lm3630a_chip *pchip,
71 unsigned int reg, unsigned int data)
72 {
73 return regmap_write(pchip->regmap, reg, data);
74 }
75
lm3630a_update(struct lm3630a_chip * pchip,unsigned int reg,unsigned int mask,unsigned int data)76 static int lm3630a_update(struct lm3630a_chip *pchip,
77 unsigned int reg, unsigned int mask,
78 unsigned int data)
79 {
80 return regmap_update_bits(pchip->regmap, reg, mask, data);
81 }
82
83 /* initialize chip */
lm3630a_chip_init(struct lm3630a_chip * pchip)84 static int lm3630a_chip_init(struct lm3630a_chip *pchip)
85 {
86 int rval;
87 struct lm3630a_platform_data *pdata = pchip->pdata;
88
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);
96 /* set current A */
97 rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
98 /* set current B */
99 rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
100 /* set control */
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);
107
108 if (rval < 0)
109 dev_err(pchip->dev, "i2c failed to access register\n");
110 return rval;
111 }
112
113 /* interrupt handling */
lm3630a_delayed_func(struct work_struct * work)114 static void lm3630a_delayed_func(struct work_struct *work)
115 {
116 int rval;
117 struct lm3630a_chip *pchip;
118
119 pchip = container_of(work, struct lm3630a_chip, work.work);
120
121 rval = lm3630a_read(pchip, REG_INT_STATUS);
122 if (rval < 0) {
123 dev_err(pchip->dev,
124 "i2c failed to access REG_INT_STATUS Register\n");
125 return;
126 }
127
128 dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
129 }
130
lm3630a_isr_func(int irq,void * chip)131 static irqreturn_t lm3630a_isr_func(int irq, void *chip)
132 {
133 int rval;
134 struct lm3630a_chip *pchip = chip;
135 unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
136
137 queue_delayed_work(pchip->irqthread, &pchip->work, delay);
138
139 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
140 if (rval < 0) {
141 dev_err(pchip->dev, "i2c failed to access register\n");
142 return IRQ_NONE;
143 }
144 return IRQ_HANDLED;
145 }
146
lm3630a_intr_config(struct lm3630a_chip * pchip)147 static int lm3630a_intr_config(struct lm3630a_chip *pchip)
148 {
149 int rval;
150
151 rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
152 if (rval < 0)
153 return rval;
154
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");
159 return -ENOMEM;
160 }
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);
166 return -ENOMEM;
167 }
168 return rval;
169 }
170
lm3630a_pwm_ctrl(struct lm3630a_chip * pchip,int br,int br_max)171 static int lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
172 {
173 int err;
174
175 pchip->pwmd_state.period = pchip->pdata->pwm_period;
176
177 err = pwm_set_relative_duty_cycle(&pchip->pwmd_state, br, br_max);
178 if (err)
179 return err;
180
181 pchip->pwmd_state.enabled = pchip->pwmd_state.duty_cycle ? true : false;
182
183 return pwm_apply_might_sleep(pchip->pwmd, &pchip->pwmd_state);
184 }
185
186 /* update and get brightness */
lm3630a_bank_a_update_status(struct backlight_device * bl)187 static int lm3630a_bank_a_update_status(struct backlight_device *bl)
188 {
189 int ret;
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);
193
194 /* pwm control */
195 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0)
196 return lm3630a_pwm_ctrl(pchip, brightness,
197 bl->props.max_brightness);
198
199 /* disable sleep */
200 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
201 if (ret < 0)
202 goto out_i2c_err;
203 usleep_range(1000, 2000);
204 /* minimum brightness is 0x04 */
205 ret = lm3630a_write(pchip, REG_BRT_A, brightness);
206
207 if (brightness < 0x4)
208 /* turn the string off */
209 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
210 else
211 ret |= lm3630a_update(pchip, REG_CTRL,
212 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
213 if (ret < 0)
214 goto out_i2c_err;
215 return 0;
216
217 out_i2c_err:
218 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
219 return ret;
220 }
221
lm3630a_bank_a_get_brightness(struct backlight_device * bl)222 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
223 {
224 int brightness, rval;
225 struct lm3630a_chip *pchip = bl_get_data(bl);
226 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
227
228 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
229 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
230 if (rval < 0)
231 goto out_i2c_err;
232 brightness = (rval & 0x01) << 8;
233 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
234 if (rval < 0)
235 goto out_i2c_err;
236 brightness |= rval;
237 return brightness;
238 }
239
240 /* disable sleep */
241 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
242 if (rval < 0)
243 goto out_i2c_err;
244 usleep_range(1000, 2000);
245 rval = lm3630a_read(pchip, REG_BRT_A);
246 if (rval < 0)
247 goto out_i2c_err;
248 return rval;
249
250 out_i2c_err:
251 dev_err(pchip->dev, "i2c failed to access register\n");
252 return 0;
253 }
254
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,
259 };
260
261 /* update and get brightness */
lm3630a_bank_b_update_status(struct backlight_device * bl)262 static int lm3630a_bank_b_update_status(struct backlight_device *bl)
263 {
264 int ret;
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);
268
269 /* pwm control */
270 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0)
271 return lm3630a_pwm_ctrl(pchip, brightness,
272 bl->props.max_brightness);
273
274 /* disable sleep */
275 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
276 if (ret < 0)
277 goto out_i2c_err;
278 usleep_range(1000, 2000);
279 /* minimum brightness is 0x04 */
280 ret = lm3630a_write(pchip, REG_BRT_B, brightness);
281
282 if (brightness < 0x4)
283 /* turn the string off */
284 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
285 else
286 ret |= lm3630a_update(pchip, REG_CTRL,
287 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
288 if (ret < 0)
289 goto out_i2c_err;
290 return 0;
291
292 out_i2c_err:
293 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
294 return ret;
295 }
296
lm3630a_bank_b_get_brightness(struct backlight_device * bl)297 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
298 {
299 int brightness, rval;
300 struct lm3630a_chip *pchip = bl_get_data(bl);
301 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
302
303 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
304 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
305 if (rval < 0)
306 goto out_i2c_err;
307 brightness = (rval & 0x01) << 8;
308 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
309 if (rval < 0)
310 goto out_i2c_err;
311 brightness |= rval;
312 return brightness;
313 }
314
315 /* disable sleep */
316 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
317 if (rval < 0)
318 goto out_i2c_err;
319 usleep_range(1000, 2000);
320 rval = lm3630a_read(pchip, REG_BRT_B);
321 if (rval < 0)
322 goto out_i2c_err;
323 return rval;
324
325 out_i2c_err:
326 dev_err(pchip->dev, "i2c failed to access register\n");
327 return 0;
328 }
329
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,
334 };
335
lm3630a_backlight_register(struct lm3630a_chip * pchip)336 static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
337 {
338 struct lm3630a_platform_data *pdata = pchip->pdata;
339 struct backlight_properties props;
340 const char *label;
341
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";
348 pchip->bleda =
349 devm_backlight_device_register(pchip->dev, label,
350 pchip->dev, pchip,
351 &lm3630a_bank_a_ops, &props);
352 if (IS_ERR(pchip->bleda))
353 return PTR_ERR(pchip->bleda);
354 }
355
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";
361 pchip->bledb =
362 devm_backlight_device_register(pchip->dev, label,
363 pchip->dev, pchip,
364 &lm3630a_bank_b_ops, &props);
365 if (IS_ERR(pchip->bledb))
366 return PTR_ERR(pchip->bledb);
367 }
368 return 0;
369 }
370
371 static const struct regmap_config lm3630a_regmap = {
372 .reg_bits = 8,
373 .val_bits = 8,
374 .max_register = REG_MAX,
375 };
376
lm3630a_parse_led_sources(struct fwnode_handle * node,int default_led_sources)377 static int lm3630a_parse_led_sources(struct fwnode_handle *node,
378 int default_led_sources)
379 {
380 u32 sources[LM3630A_NUM_SINKS];
381 int ret, num_sources, i;
382
383 num_sources = fwnode_property_count_u32(node, "led-sources");
384 if (num_sources < 0)
385 return default_led_sources;
386 else if (num_sources > ARRAY_SIZE(sources))
387 return -EINVAL;
388
389 ret = fwnode_property_read_u32_array(node, "led-sources", sources,
390 num_sources);
391 if (ret)
392 return ret;
393
394 for (i = 0; i < num_sources; i++) {
395 if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1)
396 return -EINVAL;
397
398 ret |= BIT(sources[i]);
399 }
400
401 return ret;
402 }
403
lm3630a_parse_bank(struct lm3630a_platform_data * pdata,struct fwnode_handle * node,int * seen_led_sources)404 static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
405 struct fwnode_handle *node, int *seen_led_sources)
406 {
407 int led_sources, ret;
408 const char *label;
409 u32 bank, val;
410 bool linear;
411
412 ret = fwnode_property_read_u32(node, "reg", &bank);
413 if (ret)
414 return ret;
415
416 if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1)
417 return -EINVAL;
418
419 led_sources = lm3630a_parse_led_sources(node, BIT(bank));
420 if (led_sources < 0)
421 return led_sources;
422
423 if (*seen_led_sources & led_sources)
424 return -EINVAL;
425
426 *seen_led_sources |= led_sources;
427
428 linear = fwnode_property_read_bool(node,
429 "ti,linear-mapping-mode");
430 if (bank) {
431 if (led_sources & BIT(LM3630A_SINK_0) ||
432 !(led_sources & BIT(LM3630A_SINK_1)))
433 return -EINVAL;
434
435 pdata->ledb_ctrl = linear ?
436 LM3630A_LEDB_ENABLE_LINEAR :
437 LM3630A_LEDB_ENABLE;
438 } else {
439 if (!(led_sources & BIT(LM3630A_SINK_0)))
440 return -EINVAL;
441
442 pdata->leda_ctrl = linear ?
443 LM3630A_LEDA_ENABLE_LINEAR :
444 LM3630A_LEDA_ENABLE;
445
446 if (led_sources & BIT(LM3630A_SINK_1))
447 pdata->ledb_ctrl = LM3630A_LEDB_ON_A;
448 }
449
450 ret = fwnode_property_read_string(node, "label", &label);
451 if (!ret) {
452 if (bank)
453 pdata->ledb_label = label;
454 else
455 pdata->leda_label = label;
456 }
457
458 ret = fwnode_property_read_u32(node, "default-brightness",
459 &val);
460 if (!ret) {
461 if (bank)
462 pdata->ledb_init_brt = val;
463 else
464 pdata->leda_init_brt = val;
465 }
466
467 ret = fwnode_property_read_u32(node, "max-brightness", &val);
468 if (!ret) {
469 if (bank)
470 pdata->ledb_max_brt = val;
471 else
472 pdata->leda_max_brt = val;
473 }
474
475 return 0;
476 }
477
lm3630a_parse_node(struct lm3630a_chip * pchip,struct lm3630a_platform_data * pdata)478 static int lm3630a_parse_node(struct lm3630a_chip *pchip,
479 struct lm3630a_platform_data *pdata)
480 {
481 int ret = -ENODEV, seen_led_sources = 0;
482 struct fwnode_handle *node;
483
484 device_for_each_child_node(pchip->dev, node) {
485 ret = lm3630a_parse_bank(pdata, node, &seen_led_sources);
486 if (ret) {
487 fwnode_handle_put(node);
488 return ret;
489 }
490 }
491
492 return ret;
493 }
494
lm3630a_probe(struct i2c_client * client)495 static int lm3630a_probe(struct i2c_client *client)
496 {
497 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
498 struct lm3630a_chip *pchip;
499 int rval;
500
501 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
502 dev_err(&client->dev, "fail : i2c functionality check\n");
503 return -EOPNOTSUPP;
504 }
505
506 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
507 GFP_KERNEL);
508 if (!pchip)
509 return -ENOMEM;
510 pchip->dev = &client->dev;
511
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);
516 return rval;
517 }
518
519 i2c_set_clientdata(client, pchip);
520 if (pdata == NULL) {
521 pdata = devm_kzalloc(pchip->dev,
522 sizeof(struct lm3630a_platform_data),
523 GFP_KERNEL);
524 if (pdata == NULL)
525 return -ENOMEM;
526
527 /* default values */
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;
532
533 rval = lm3630a_parse_node(pchip, pdata);
534 if (rval) {
535 dev_err(&client->dev, "fail : parse node\n");
536 return rval;
537 }
538 }
539 pchip->pdata = pdata;
540
541 pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
542 GPIOD_OUT_HIGH);
543 if (IS_ERR(pchip->enable_gpio))
544 return PTR_ERR(pchip->enable_gpio);
545
546 /* chip initialize */
547 rval = lm3630a_chip_init(pchip);
548 if (rval < 0) {
549 dev_err(&client->dev, "fail : init chip\n");
550 return rval;
551 }
552 /* backlight register */
553 rval = lm3630a_backlight_register(pchip);
554 if (rval < 0) {
555 dev_err(&client->dev, "fail : backlight register.\n");
556 return rval;
557 }
558 /* pwm */
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");
564
565 pwm_init_state(pchip->pwmd, &pchip->pwmd_state);
566 }
567
568 /* interrupt enable : irq 0 is not allowed */
569 pchip->irq = client->irq;
570 if (pchip->irq) {
571 rval = lm3630a_intr_config(pchip);
572 if (rval < 0)
573 return rval;
574 }
575 dev_info(&client->dev, "LM3630A backlight register OK.\n");
576 return 0;
577 }
578
lm3630a_remove(struct i2c_client * client)579 static void lm3630a_remove(struct i2c_client *client)
580 {
581 int rval;
582 struct lm3630a_chip *pchip = i2c_get_clientdata(client);
583
584 rval = lm3630a_write(pchip, REG_BRT_A, 0);
585 if (rval < 0)
586 dev_err(pchip->dev, "i2c failed to access register\n");
587
588 rval = lm3630a_write(pchip, REG_BRT_B, 0);
589 if (rval < 0)
590 dev_err(pchip->dev, "i2c failed to access register\n");
591
592 if (pchip->irq) {
593 free_irq(pchip->irq, pchip);
594 destroy_workqueue(pchip->irqthread);
595 }
596 }
597
598 static const struct i2c_device_id lm3630a_id[] = {
599 { LM3630A_NAME },
600 {}
601 };
602
603 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
604
605 static const struct of_device_id lm3630a_match_table[] = {
606 { .compatible = "ti,lm3630a", },
607 { },
608 };
609
610 MODULE_DEVICE_TABLE(of, lm3630a_match_table);
611
612 static struct i2c_driver lm3630a_i2c_driver = {
613 .driver = {
614 .name = LM3630A_NAME,
615 .of_match_table = lm3630a_match_table,
616 },
617 .probe = lm3630a_probe,
618 .remove = lm3630a_remove,
619 .id_table = lm3630a_id,
620 };
621
622 module_i2c_driver(lm3630a_i2c_driver);
623
624 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
625 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
626 MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
627 MODULE_LICENSE("GPL v2");
628