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
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
206 if (backlight_is_blank(bl) || (backlight_get_brightness(bl) < 0x4))
207 /* turn the string off */
208 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
209 else
210 ret |= lm3630a_update(pchip, REG_CTRL,
211 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
212 if (ret < 0)
213 goto out_i2c_err;
214 return 0;
215
216 out_i2c_err:
217 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
218 return ret;
219 }
220
lm3630a_bank_a_get_brightness(struct backlight_device * bl)221 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
222 {
223 int brightness, rval;
224 struct lm3630a_chip *pchip = bl_get_data(bl);
225 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
226
227 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
228 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
229 if (rval < 0)
230 goto out_i2c_err;
231 brightness = (rval & 0x01) << 8;
232 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
233 if (rval < 0)
234 goto out_i2c_err;
235 brightness |= rval;
236 return brightness;
237 }
238
239 /* disable sleep */
240 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
241 if (rval < 0)
242 goto out_i2c_err;
243 usleep_range(1000, 2000);
244 rval = lm3630a_read(pchip, REG_BRT_A);
245 if (rval < 0)
246 goto out_i2c_err;
247 return rval;
248
249 out_i2c_err:
250 dev_err(pchip->dev, "i2c failed to access register\n");
251 return 0;
252 }
253
254 static const struct backlight_ops lm3630a_bank_a_ops = {
255 .options = BL_CORE_SUSPENDRESUME,
256 .update_status = lm3630a_bank_a_update_status,
257 .get_brightness = lm3630a_bank_a_get_brightness,
258 };
259
260 /* update and get brightness */
lm3630a_bank_b_update_status(struct backlight_device * bl)261 static int lm3630a_bank_b_update_status(struct backlight_device *bl)
262 {
263 int ret;
264 struct lm3630a_chip *pchip = bl_get_data(bl);
265 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
266
267 /* pwm control */
268 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0)
269 return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
270 bl->props.max_brightness);
271
272 /* disable sleep */
273 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
274 if (ret < 0)
275 goto out_i2c_err;
276 usleep_range(1000, 2000);
277 /* minimum brightness is 0x04 */
278 ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
279
280 if (backlight_is_blank(bl) || (backlight_get_brightness(bl) < 0x4))
281 /* turn the string off */
282 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
283 else
284 ret |= lm3630a_update(pchip, REG_CTRL,
285 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
286 if (ret < 0)
287 goto out_i2c_err;
288 return 0;
289
290 out_i2c_err:
291 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
292 return ret;
293 }
294
lm3630a_bank_b_get_brightness(struct backlight_device * bl)295 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
296 {
297 int brightness, rval;
298 struct lm3630a_chip *pchip = bl_get_data(bl);
299 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
300
301 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
302 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
303 if (rval < 0)
304 goto out_i2c_err;
305 brightness = (rval & 0x01) << 8;
306 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
307 if (rval < 0)
308 goto out_i2c_err;
309 brightness |= rval;
310 return brightness;
311 }
312
313 /* disable sleep */
314 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
315 if (rval < 0)
316 goto out_i2c_err;
317 usleep_range(1000, 2000);
318 rval = lm3630a_read(pchip, REG_BRT_B);
319 if (rval < 0)
320 goto out_i2c_err;
321 return rval;
322
323 out_i2c_err:
324 dev_err(pchip->dev, "i2c failed to access register\n");
325 return 0;
326 }
327
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,
332 };
333
lm3630a_backlight_register(struct lm3630a_chip * pchip)334 static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
335 {
336 struct lm3630a_platform_data *pdata = pchip->pdata;
337 struct backlight_properties props;
338 const char *label;
339
340 memset(&props, 0, sizeof(struct backlight_properties));
341 props.type = BACKLIGHT_RAW;
342 if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
343 props.brightness = pdata->leda_init_brt;
344 props.max_brightness = pdata->leda_max_brt;
345 label = pdata->leda_label ? pdata->leda_label : "lm3630a_leda";
346 pchip->bleda =
347 devm_backlight_device_register(pchip->dev, label,
348 pchip->dev, pchip,
349 &lm3630a_bank_a_ops, &props);
350 if (IS_ERR(pchip->bleda))
351 return PTR_ERR(pchip->bleda);
352 }
353
354 if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
355 (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
356 props.brightness = pdata->ledb_init_brt;
357 props.max_brightness = pdata->ledb_max_brt;
358 label = pdata->ledb_label ? pdata->ledb_label : "lm3630a_ledb";
359 pchip->bledb =
360 devm_backlight_device_register(pchip->dev, label,
361 pchip->dev, pchip,
362 &lm3630a_bank_b_ops, &props);
363 if (IS_ERR(pchip->bledb))
364 return PTR_ERR(pchip->bledb);
365 }
366 return 0;
367 }
368
369 static const struct regmap_config lm3630a_regmap = {
370 .reg_bits = 8,
371 .val_bits = 8,
372 .max_register = REG_MAX,
373 };
374
lm3630a_parse_led_sources(struct fwnode_handle * node,int default_led_sources)375 static int lm3630a_parse_led_sources(struct fwnode_handle *node,
376 int default_led_sources)
377 {
378 u32 sources[LM3630A_NUM_SINKS];
379 int ret, num_sources, i;
380
381 num_sources = fwnode_property_count_u32(node, "led-sources");
382 if (num_sources < 0)
383 return default_led_sources;
384 else if (num_sources > ARRAY_SIZE(sources))
385 return -EINVAL;
386
387 ret = fwnode_property_read_u32_array(node, "led-sources", sources,
388 num_sources);
389 if (ret)
390 return ret;
391
392 for (i = 0; i < num_sources; i++) {
393 if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1)
394 return -EINVAL;
395
396 ret |= BIT(sources[i]);
397 }
398
399 return ret;
400 }
401
lm3630a_parse_bank(struct lm3630a_platform_data * pdata,struct fwnode_handle * node,int * seen_led_sources)402 static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
403 struct fwnode_handle *node, int *seen_led_sources)
404 {
405 int led_sources, ret;
406 const char *label;
407 u32 bank, val;
408 bool linear;
409
410 ret = fwnode_property_read_u32(node, "reg", &bank);
411 if (ret)
412 return ret;
413
414 if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1)
415 return -EINVAL;
416
417 led_sources = lm3630a_parse_led_sources(node, BIT(bank));
418 if (led_sources < 0)
419 return led_sources;
420
421 if (*seen_led_sources & led_sources)
422 return -EINVAL;
423
424 *seen_led_sources |= led_sources;
425
426 linear = fwnode_property_read_bool(node,
427 "ti,linear-mapping-mode");
428 if (bank) {
429 if (led_sources & BIT(LM3630A_SINK_0) ||
430 !(led_sources & BIT(LM3630A_SINK_1)))
431 return -EINVAL;
432
433 pdata->ledb_ctrl = linear ?
434 LM3630A_LEDB_ENABLE_LINEAR :
435 LM3630A_LEDB_ENABLE;
436 } else {
437 if (!(led_sources & BIT(LM3630A_SINK_0)))
438 return -EINVAL;
439
440 pdata->leda_ctrl = linear ?
441 LM3630A_LEDA_ENABLE_LINEAR :
442 LM3630A_LEDA_ENABLE;
443
444 if (led_sources & BIT(LM3630A_SINK_1))
445 pdata->ledb_ctrl = LM3630A_LEDB_ON_A;
446 }
447
448 ret = fwnode_property_read_string(node, "label", &label);
449 if (!ret) {
450 if (bank)
451 pdata->ledb_label = label;
452 else
453 pdata->leda_label = label;
454 }
455
456 ret = fwnode_property_read_u32(node, "default-brightness",
457 &val);
458 if (!ret) {
459 if (bank)
460 pdata->ledb_init_brt = val;
461 else
462 pdata->leda_init_brt = val;
463 }
464
465 ret = fwnode_property_read_u32(node, "max-brightness", &val);
466 if (!ret) {
467 if (bank)
468 pdata->ledb_max_brt = val;
469 else
470 pdata->leda_max_brt = val;
471 }
472
473 return 0;
474 }
475
lm3630a_parse_node(struct lm3630a_chip * pchip,struct lm3630a_platform_data * pdata)476 static int lm3630a_parse_node(struct lm3630a_chip *pchip,
477 struct lm3630a_platform_data *pdata)
478 {
479 int ret = -ENODEV, seen_led_sources = 0;
480 struct fwnode_handle *node;
481
482 device_for_each_child_node(pchip->dev, node) {
483 ret = lm3630a_parse_bank(pdata, node, &seen_led_sources);
484 if (ret) {
485 fwnode_handle_put(node);
486 return ret;
487 }
488 }
489
490 return ret;
491 }
492
lm3630a_probe(struct i2c_client * client)493 static int lm3630a_probe(struct i2c_client *client)
494 {
495 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
496 struct lm3630a_chip *pchip;
497 int rval;
498
499 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
500 dev_err(&client->dev, "fail : i2c functionality check\n");
501 return -EOPNOTSUPP;
502 }
503
504 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
505 GFP_KERNEL);
506 if (!pchip)
507 return -ENOMEM;
508 pchip->dev = &client->dev;
509
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);
514 return rval;
515 }
516
517 i2c_set_clientdata(client, pchip);
518 if (pdata == NULL) {
519 pdata = devm_kzalloc(pchip->dev,
520 sizeof(struct lm3630a_platform_data),
521 GFP_KERNEL);
522 if (pdata == NULL)
523 return -ENOMEM;
524
525 /* default values */
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;
530
531 rval = lm3630a_parse_node(pchip, pdata);
532 if (rval) {
533 dev_err(&client->dev, "fail : parse node\n");
534 return rval;
535 }
536 }
537 pchip->pdata = pdata;
538
539 pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
540 GPIOD_OUT_HIGH);
541 if (IS_ERR(pchip->enable_gpio)) {
542 rval = PTR_ERR(pchip->enable_gpio);
543 return rval;
544 }
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 dev_err(&client->dev, "fail : get pwm device\n");
563 return PTR_ERR(pchip->pwmd);
564 }
565
566 pwm_init_state(pchip->pwmd, &pchip->pwmd_state);
567 }
568
569 /* interrupt enable : irq 0 is not allowed */
570 pchip->irq = client->irq;
571 if (pchip->irq) {
572 rval = lm3630a_intr_config(pchip);
573 if (rval < 0)
574 return rval;
575 }
576 dev_info(&client->dev, "LM3630A backlight register OK.\n");
577 return 0;
578 }
579
lm3630a_remove(struct i2c_client * client)580 static void lm3630a_remove(struct i2c_client *client)
581 {
582 int rval;
583 struct lm3630a_chip *pchip = i2c_get_clientdata(client);
584
585 rval = lm3630a_write(pchip, REG_BRT_A, 0);
586 if (rval < 0)
587 dev_err(pchip->dev, "i2c failed to access register\n");
588
589 rval = lm3630a_write(pchip, REG_BRT_B, 0);
590 if (rval < 0)
591 dev_err(pchip->dev, "i2c failed to access register\n");
592
593 if (pchip->irq) {
594 free_irq(pchip->irq, pchip);
595 destroy_workqueue(pchip->irqthread);
596 }
597 }
598
599 static const struct i2c_device_id lm3630a_id[] = {
600 {LM3630A_NAME, 0},
601 {}
602 };
603
604 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
605
606 static const struct of_device_id lm3630a_match_table[] = {
607 { .compatible = "ti,lm3630a", },
608 { },
609 };
610
611 MODULE_DEVICE_TABLE(of, lm3630a_match_table);
612
613 static struct i2c_driver lm3630a_i2c_driver = {
614 .driver = {
615 .name = LM3630A_NAME,
616 .of_match_table = lm3630a_match_table,
617 },
618 .probe = lm3630a_probe,
619 .remove = lm3630a_remove,
620 .id_table = lm3630a_id,
621 };
622
623 module_i2c_driver(lm3630a_i2c_driver);
624
625 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
626 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
627 MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
628 MODULE_LICENSE("GPL v2");
629