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_state(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
193 /* pwm control */
194 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0)
195 return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
196 bl->props.max_brightness);
197
198 /* disable sleep */
199 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
200 if (ret < 0)
201 goto out_i2c_err;
202 usleep_range(1000, 2000);
203 /* minimum brightness is 0x04 */
204 ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
205 if (bl->props.brightness < 0x4)
206 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
207 else
208 ret |= lm3630a_update(pchip, REG_CTRL,
209 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
210 if (ret < 0)
211 goto out_i2c_err;
212 return 0;
213
214 out_i2c_err:
215 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
216 return ret;
217 }
218
lm3630a_bank_a_get_brightness(struct backlight_device * bl)219 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
220 {
221 int brightness, rval;
222 struct lm3630a_chip *pchip = bl_get_data(bl);
223 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
224
225 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
226 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
227 if (rval < 0)
228 goto out_i2c_err;
229 brightness = (rval & 0x01) << 8;
230 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
231 if (rval < 0)
232 goto out_i2c_err;
233 brightness |= rval;
234 goto out;
235 }
236
237 /* disable sleep */
238 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
239 if (rval < 0)
240 goto out_i2c_err;
241 usleep_range(1000, 2000);
242 rval = lm3630a_read(pchip, REG_BRT_A);
243 if (rval < 0)
244 goto out_i2c_err;
245 brightness = rval;
246
247 out:
248 bl->props.brightness = brightness;
249 return bl->props.brightness;
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
268 /* pwm control */
269 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0)
270 return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
271 bl->props.max_brightness);
272
273 /* disable sleep */
274 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
275 if (ret < 0)
276 goto out_i2c_err;
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);
282 else
283 ret |= lm3630a_update(pchip, REG_CTRL,
284 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
285 if (ret < 0)
286 goto out_i2c_err;
287 return 0;
288
289 out_i2c_err:
290 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
291 return ret;
292 }
293
lm3630a_bank_b_get_brightness(struct backlight_device * bl)294 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
295 {
296 int brightness, rval;
297 struct lm3630a_chip *pchip = bl_get_data(bl);
298 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
299
300 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
301 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
302 if (rval < 0)
303 goto out_i2c_err;
304 brightness = (rval & 0x01) << 8;
305 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
306 if (rval < 0)
307 goto out_i2c_err;
308 brightness |= rval;
309 goto out;
310 }
311
312 /* disable sleep */
313 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
314 if (rval < 0)
315 goto out_i2c_err;
316 usleep_range(1000, 2000);
317 rval = lm3630a_read(pchip, REG_BRT_B);
318 if (rval < 0)
319 goto out_i2c_err;
320 brightness = rval;
321
322 out:
323 bl->props.brightness = brightness;
324 return bl->props.brightness;
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 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";
347 pchip->bleda =
348 devm_backlight_device_register(pchip->dev, label,
349 pchip->dev, pchip,
350 &lm3630a_bank_a_ops, &props);
351 if (IS_ERR(pchip->bleda))
352 return PTR_ERR(pchip->bleda);
353 }
354
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";
360 pchip->bledb =
361 devm_backlight_device_register(pchip->dev, label,
362 pchip->dev, pchip,
363 &lm3630a_bank_b_ops, &props);
364 if (IS_ERR(pchip->bledb))
365 return PTR_ERR(pchip->bledb);
366 }
367 return 0;
368 }
369
370 static const struct regmap_config lm3630a_regmap = {
371 .reg_bits = 8,
372 .val_bits = 8,
373 .max_register = REG_MAX,
374 };
375
lm3630a_parse_led_sources(struct fwnode_handle * node,int default_led_sources)376 static int lm3630a_parse_led_sources(struct fwnode_handle *node,
377 int default_led_sources)
378 {
379 u32 sources[LM3630A_NUM_SINKS];
380 int ret, num_sources, i;
381
382 num_sources = fwnode_property_count_u32(node, "led-sources");
383 if (num_sources < 0)
384 return default_led_sources;
385 else if (num_sources > ARRAY_SIZE(sources))
386 return -EINVAL;
387
388 ret = fwnode_property_read_u32_array(node, "led-sources", sources,
389 num_sources);
390 if (ret)
391 return ret;
392
393 for (i = 0; i < num_sources; i++) {
394 if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1)
395 return -EINVAL;
396
397 ret |= BIT(sources[i]);
398 }
399
400 return ret;
401 }
402
lm3630a_parse_bank(struct lm3630a_platform_data * pdata,struct fwnode_handle * node,int * seen_led_sources)403 static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
404 struct fwnode_handle *node, int *seen_led_sources)
405 {
406 int led_sources, ret;
407 const char *label;
408 u32 bank, val;
409 bool linear;
410
411 ret = fwnode_property_read_u32(node, "reg", &bank);
412 if (ret)
413 return ret;
414
415 if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1)
416 return -EINVAL;
417
418 led_sources = lm3630a_parse_led_sources(node, BIT(bank));
419 if (led_sources < 0)
420 return led_sources;
421
422 if (*seen_led_sources & led_sources)
423 return -EINVAL;
424
425 *seen_led_sources |= led_sources;
426
427 linear = fwnode_property_read_bool(node,
428 "ti,linear-mapping-mode");
429 if (bank) {
430 if (led_sources & BIT(LM3630A_SINK_0) ||
431 !(led_sources & BIT(LM3630A_SINK_1)))
432 return -EINVAL;
433
434 pdata->ledb_ctrl = linear ?
435 LM3630A_LEDB_ENABLE_LINEAR :
436 LM3630A_LEDB_ENABLE;
437 } else {
438 if (!(led_sources & BIT(LM3630A_SINK_0)))
439 return -EINVAL;
440
441 pdata->leda_ctrl = linear ?
442 LM3630A_LEDA_ENABLE_LINEAR :
443 LM3630A_LEDA_ENABLE;
444
445 if (led_sources & BIT(LM3630A_SINK_1))
446 pdata->ledb_ctrl = LM3630A_LEDB_ON_A;
447 }
448
449 ret = fwnode_property_read_string(node, "label", &label);
450 if (!ret) {
451 if (bank)
452 pdata->ledb_label = label;
453 else
454 pdata->leda_label = label;
455 }
456
457 ret = fwnode_property_read_u32(node, "default-brightness",
458 &val);
459 if (!ret) {
460 if (bank)
461 pdata->ledb_init_brt = val;
462 else
463 pdata->leda_init_brt = val;
464 }
465
466 ret = fwnode_property_read_u32(node, "max-brightness", &val);
467 if (!ret) {
468 if (bank)
469 pdata->ledb_max_brt = val;
470 else
471 pdata->leda_max_brt = val;
472 }
473
474 return 0;
475 }
476
lm3630a_parse_node(struct lm3630a_chip * pchip,struct lm3630a_platform_data * pdata)477 static int lm3630a_parse_node(struct lm3630a_chip *pchip,
478 struct lm3630a_platform_data *pdata)
479 {
480 int ret = -ENODEV, seen_led_sources = 0;
481 struct fwnode_handle *node;
482
483 device_for_each_child_node(pchip->dev, node) {
484 ret = lm3630a_parse_bank(pdata, node, &seen_led_sources);
485 if (ret) {
486 fwnode_handle_put(node);
487 return ret;
488 }
489 }
490
491 return ret;
492 }
493
lm3630a_probe(struct i2c_client * client)494 static int lm3630a_probe(struct i2c_client *client)
495 {
496 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
497 struct lm3630a_chip *pchip;
498 int rval;
499
500 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
501 dev_err(&client->dev, "fail : i2c functionality check\n");
502 return -EOPNOTSUPP;
503 }
504
505 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
506 GFP_KERNEL);
507 if (!pchip)
508 return -ENOMEM;
509 pchip->dev = &client->dev;
510
511 pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
512 if (IS_ERR(pchip->regmap)) {
513 rval = PTR_ERR(pchip->regmap);
514 dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
515 return rval;
516 }
517
518 i2c_set_clientdata(client, pchip);
519 if (pdata == NULL) {
520 pdata = devm_kzalloc(pchip->dev,
521 sizeof(struct lm3630a_platform_data),
522 GFP_KERNEL);
523 if (pdata == NULL)
524 return -ENOMEM;
525
526 /* default values */
527 pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
528 pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
529 pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
530 pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
531
532 rval = lm3630a_parse_node(pchip, pdata);
533 if (rval) {
534 dev_err(&client->dev, "fail : parse node\n");
535 return rval;
536 }
537 }
538 pchip->pdata = pdata;
539
540 pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
541 GPIOD_OUT_HIGH);
542 if (IS_ERR(pchip->enable_gpio)) {
543 rval = PTR_ERR(pchip->enable_gpio);
544 return rval;
545 }
546
547 /* chip initialize */
548 rval = lm3630a_chip_init(pchip);
549 if (rval < 0) {
550 dev_err(&client->dev, "fail : init chip\n");
551 return rval;
552 }
553 /* backlight register */
554 rval = lm3630a_backlight_register(pchip);
555 if (rval < 0) {
556 dev_err(&client->dev, "fail : backlight register.\n");
557 return rval;
558 }
559 /* pwm */
560 if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
561 pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
562 if (IS_ERR(pchip->pwmd)) {
563 dev_err(&client->dev, "fail : get pwm device\n");
564 return PTR_ERR(pchip->pwmd);
565 }
566
567 pwm_init_state(pchip->pwmd, &pchip->pwmd_state);
568 }
569
570 /* interrupt enable : irq 0 is not allowed */
571 pchip->irq = client->irq;
572 if (pchip->irq) {
573 rval = lm3630a_intr_config(pchip);
574 if (rval < 0)
575 return rval;
576 }
577 dev_info(&client->dev, "LM3630A backlight register OK.\n");
578 return 0;
579 }
580
lm3630a_remove(struct i2c_client * client)581 static void lm3630a_remove(struct i2c_client *client)
582 {
583 int rval;
584 struct lm3630a_chip *pchip = i2c_get_clientdata(client);
585
586 rval = lm3630a_write(pchip, REG_BRT_A, 0);
587 if (rval < 0)
588 dev_err(pchip->dev, "i2c failed to access register\n");
589
590 rval = lm3630a_write(pchip, REG_BRT_B, 0);
591 if (rval < 0)
592 dev_err(pchip->dev, "i2c failed to access register\n");
593
594 if (pchip->irq) {
595 free_irq(pchip->irq, pchip);
596 destroy_workqueue(pchip->irqthread);
597 }
598 }
599
600 static const struct i2c_device_id lm3630a_id[] = {
601 {LM3630A_NAME, 0},
602 {}
603 };
604
605 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
606
607 static const struct of_device_id lm3630a_match_table[] = {
608 { .compatible = "ti,lm3630a", },
609 { },
610 };
611
612 MODULE_DEVICE_TABLE(of, lm3630a_match_table);
613
614 static struct i2c_driver lm3630a_i2c_driver = {
615 .driver = {
616 .name = LM3630A_NAME,
617 .of_match_table = lm3630a_match_table,
618 },
619 .probe_new = lm3630a_probe,
620 .remove = lm3630a_remove,
621 .id_table = lm3630a_id,
622 };
623
624 module_i2c_driver(lm3630a_i2c_driver);
625
626 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
627 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
628 MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
629 MODULE_LICENSE("GPL v2");
630