1 /*
2 * Simple driver for Texas Instruments LM3630A Backlight driver chip
3 * Copyright (C) 2012 Texas Instruments
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 */
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/i2c.h>
13 #include <linux/backlight.h>
14 #include <linux/err.h>
15 #include <linux/delay.h>
16 #include <linux/uaccess.h>
17 #include <linux/interrupt.h>
18 #include <linux/regmap.h>
19 #include <linux/pwm.h>
20 #include <linux/platform_data/lm3630a_bl.h>
21
22 #define REG_CTRL 0x00
23 #define REG_BOOST 0x02
24 #define REG_CONFIG 0x01
25 #define REG_BRT_A 0x03
26 #define REG_BRT_B 0x04
27 #define REG_I_A 0x05
28 #define REG_I_B 0x06
29 #define REG_INT_STATUS 0x09
30 #define REG_INT_EN 0x0A
31 #define REG_FAULT 0x0B
32 #define REG_PWM_OUTLOW 0x12
33 #define REG_PWM_OUTHIGH 0x13
34 #define REG_MAX 0x1F
35
36 #define INT_DEBOUNCE_MSEC 10
37 struct lm3630a_chip {
38 struct device *dev;
39 struct delayed_work work;
40
41 int irq;
42 struct workqueue_struct *irqthread;
43 struct lm3630a_platform_data *pdata;
44 struct backlight_device *bleda;
45 struct backlight_device *bledb;
46 struct regmap *regmap;
47 struct pwm_device *pwmd;
48 };
49
50 /* i2c access */
lm3630a_read(struct lm3630a_chip * pchip,unsigned int reg)51 static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
52 {
53 int rval;
54 unsigned int reg_val;
55
56 rval = regmap_read(pchip->regmap, reg, ®_val);
57 if (rval < 0)
58 return rval;
59 return reg_val & 0xFF;
60 }
61
lm3630a_write(struct lm3630a_chip * pchip,unsigned int reg,unsigned int data)62 static int lm3630a_write(struct lm3630a_chip *pchip,
63 unsigned int reg, unsigned int data)
64 {
65 return regmap_write(pchip->regmap, reg, data);
66 }
67
lm3630a_update(struct lm3630a_chip * pchip,unsigned int reg,unsigned int mask,unsigned int data)68 static int lm3630a_update(struct lm3630a_chip *pchip,
69 unsigned int reg, unsigned int mask,
70 unsigned int data)
71 {
72 return regmap_update_bits(pchip->regmap, reg, mask, data);
73 }
74
75 /* initialize chip */
lm3630a_chip_init(struct lm3630a_chip * pchip)76 static int lm3630a_chip_init(struct lm3630a_chip *pchip)
77 {
78 int rval;
79 struct lm3630a_platform_data *pdata = pchip->pdata;
80
81 usleep_range(1000, 2000);
82 /* set Filter Strength Register */
83 rval = lm3630a_write(pchip, 0x50, 0x03);
84 /* set Cofig. register */
85 rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
86 /* set boost control */
87 rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
88 /* set current A */
89 rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
90 /* set current B */
91 rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
92 /* set control */
93 rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
94 rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
95 usleep_range(1000, 2000);
96 /* set brightness A and B */
97 rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
98 rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);
99
100 if (rval < 0)
101 dev_err(pchip->dev, "i2c failed to access register\n");
102 return rval;
103 }
104
105 /* interrupt handling */
lm3630a_delayed_func(struct work_struct * work)106 static void lm3630a_delayed_func(struct work_struct *work)
107 {
108 int rval;
109 struct lm3630a_chip *pchip;
110
111 pchip = container_of(work, struct lm3630a_chip, work.work);
112
113 rval = lm3630a_read(pchip, REG_INT_STATUS);
114 if (rval < 0) {
115 dev_err(pchip->dev,
116 "i2c failed to access REG_INT_STATUS Register\n");
117 return;
118 }
119
120 dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
121 }
122
lm3630a_isr_func(int irq,void * chip)123 static irqreturn_t lm3630a_isr_func(int irq, void *chip)
124 {
125 int rval;
126 struct lm3630a_chip *pchip = chip;
127 unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
128
129 queue_delayed_work(pchip->irqthread, &pchip->work, delay);
130
131 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
132 if (rval < 0) {
133 dev_err(pchip->dev, "i2c failed to access register\n");
134 return IRQ_NONE;
135 }
136 return IRQ_HANDLED;
137 }
138
lm3630a_intr_config(struct lm3630a_chip * pchip)139 static int lm3630a_intr_config(struct lm3630a_chip *pchip)
140 {
141 int rval;
142
143 rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
144 if (rval < 0)
145 return rval;
146
147 INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
148 pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
149 if (!pchip->irqthread) {
150 dev_err(pchip->dev, "create irq thread fail\n");
151 return -ENOMEM;
152 }
153 if (request_threaded_irq
154 (pchip->irq, NULL, lm3630a_isr_func,
155 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
156 dev_err(pchip->dev, "request threaded irq fail\n");
157 destroy_workqueue(pchip->irqthread);
158 return -ENOMEM;
159 }
160 return rval;
161 }
162
lm3630a_pwm_ctrl(struct lm3630a_chip * pchip,int br,int br_max)163 static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
164 {
165 unsigned int period = pchip->pdata->pwm_period;
166 unsigned int duty = br * period / br_max;
167
168 pwm_config(pchip->pwmd, duty, period);
169 if (duty)
170 pwm_enable(pchip->pwmd);
171 else
172 pwm_disable(pchip->pwmd);
173 }
174
175 /* update and get brightness */
lm3630a_bank_a_update_status(struct backlight_device * bl)176 static int lm3630a_bank_a_update_status(struct backlight_device *bl)
177 {
178 int ret;
179 struct lm3630a_chip *pchip = bl_get_data(bl);
180 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
181
182 /* pwm control */
183 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
184 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
185 bl->props.max_brightness);
186 return bl->props.brightness;
187 }
188
189 /* disable sleep */
190 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
191 if (ret < 0)
192 goto out_i2c_err;
193 usleep_range(1000, 2000);
194 /* minimum brightness is 0x04 */
195 ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
196 if (bl->props.brightness < 0x4)
197 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
198 else
199 ret |= lm3630a_update(pchip, REG_CTRL,
200 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
201 if (ret < 0)
202 goto out_i2c_err;
203 return bl->props.brightness;
204
205 out_i2c_err:
206 dev_err(pchip->dev, "i2c failed to access\n");
207 return bl->props.brightness;
208 }
209
lm3630a_bank_a_get_brightness(struct backlight_device * bl)210 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
211 {
212 int brightness, rval;
213 struct lm3630a_chip *pchip = bl_get_data(bl);
214 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
215
216 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
217 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
218 if (rval < 0)
219 goto out_i2c_err;
220 brightness = (rval & 0x01) << 8;
221 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
222 if (rval < 0)
223 goto out_i2c_err;
224 brightness |= rval;
225 goto out;
226 }
227
228 /* disable sleep */
229 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
230 if (rval < 0)
231 goto out_i2c_err;
232 usleep_range(1000, 2000);
233 rval = lm3630a_read(pchip, REG_BRT_A);
234 if (rval < 0)
235 goto out_i2c_err;
236 brightness = rval;
237
238 out:
239 bl->props.brightness = brightness;
240 return bl->props.brightness;
241 out_i2c_err:
242 dev_err(pchip->dev, "i2c failed to access register\n");
243 return 0;
244 }
245
246 static const struct backlight_ops lm3630a_bank_a_ops = {
247 .options = BL_CORE_SUSPENDRESUME,
248 .update_status = lm3630a_bank_a_update_status,
249 .get_brightness = lm3630a_bank_a_get_brightness,
250 };
251
252 /* update and get brightness */
lm3630a_bank_b_update_status(struct backlight_device * bl)253 static int lm3630a_bank_b_update_status(struct backlight_device *bl)
254 {
255 int ret;
256 struct lm3630a_chip *pchip = bl_get_data(bl);
257 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
258
259 /* pwm control */
260 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
261 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
262 bl->props.max_brightness);
263 return bl->props.brightness;
264 }
265
266 /* disable sleep */
267 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
268 if (ret < 0)
269 goto out_i2c_err;
270 usleep_range(1000, 2000);
271 /* minimum brightness is 0x04 */
272 ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
273 if (bl->props.brightness < 0x4)
274 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
275 else
276 ret |= lm3630a_update(pchip, REG_CTRL,
277 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
278 if (ret < 0)
279 goto out_i2c_err;
280 return bl->props.brightness;
281
282 out_i2c_err:
283 dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
284 return bl->props.brightness;
285 }
286
lm3630a_bank_b_get_brightness(struct backlight_device * bl)287 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
288 {
289 int brightness, rval;
290 struct lm3630a_chip *pchip = bl_get_data(bl);
291 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
292
293 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
294 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
295 if (rval < 0)
296 goto out_i2c_err;
297 brightness = (rval & 0x01) << 8;
298 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
299 if (rval < 0)
300 goto out_i2c_err;
301 brightness |= rval;
302 goto out;
303 }
304
305 /* disable sleep */
306 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
307 if (rval < 0)
308 goto out_i2c_err;
309 usleep_range(1000, 2000);
310 rval = lm3630a_read(pchip, REG_BRT_B);
311 if (rval < 0)
312 goto out_i2c_err;
313 brightness = rval;
314
315 out:
316 bl->props.brightness = brightness;
317 return bl->props.brightness;
318 out_i2c_err:
319 dev_err(pchip->dev, "i2c failed to access register\n");
320 return 0;
321 }
322
323 static const struct backlight_ops lm3630a_bank_b_ops = {
324 .options = BL_CORE_SUSPENDRESUME,
325 .update_status = lm3630a_bank_b_update_status,
326 .get_brightness = lm3630a_bank_b_get_brightness,
327 };
328
lm3630a_backlight_register(struct lm3630a_chip * pchip)329 static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
330 {
331 struct backlight_properties props;
332 struct lm3630a_platform_data *pdata = pchip->pdata;
333
334 props.type = BACKLIGHT_RAW;
335 if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
336 props.brightness = pdata->leda_init_brt;
337 props.max_brightness = pdata->leda_max_brt;
338 pchip->bleda =
339 devm_backlight_device_register(pchip->dev, "lm3630a_leda",
340 pchip->dev, pchip,
341 &lm3630a_bank_a_ops, &props);
342 if (IS_ERR(pchip->bleda))
343 return PTR_ERR(pchip->bleda);
344 }
345
346 if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
347 (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
348 props.brightness = pdata->ledb_init_brt;
349 props.max_brightness = pdata->ledb_max_brt;
350 pchip->bledb =
351 devm_backlight_device_register(pchip->dev, "lm3630a_ledb",
352 pchip->dev, pchip,
353 &lm3630a_bank_b_ops, &props);
354 if (IS_ERR(pchip->bledb))
355 return PTR_ERR(pchip->bledb);
356 }
357 return 0;
358 }
359
360 static const struct regmap_config lm3630a_regmap = {
361 .reg_bits = 8,
362 .val_bits = 8,
363 .max_register = REG_MAX,
364 };
365
lm3630a_probe(struct i2c_client * client,const struct i2c_device_id * id)366 static int lm3630a_probe(struct i2c_client *client,
367 const struct i2c_device_id *id)
368 {
369 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
370 struct lm3630a_chip *pchip;
371 int rval;
372
373 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
374 dev_err(&client->dev, "fail : i2c functionality check\n");
375 return -EOPNOTSUPP;
376 }
377
378 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
379 GFP_KERNEL);
380 if (!pchip)
381 return -ENOMEM;
382 pchip->dev = &client->dev;
383
384 pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
385 if (IS_ERR(pchip->regmap)) {
386 rval = PTR_ERR(pchip->regmap);
387 dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
388 return rval;
389 }
390
391 i2c_set_clientdata(client, pchip);
392 if (pdata == NULL) {
393 pdata = devm_kzalloc(pchip->dev,
394 sizeof(struct lm3630a_platform_data),
395 GFP_KERNEL);
396 if (pdata == NULL)
397 return -ENOMEM;
398 /* default values */
399 pdata->leda_ctrl = LM3630A_LEDA_ENABLE;
400 pdata->ledb_ctrl = LM3630A_LEDB_ENABLE;
401 pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
402 pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
403 pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
404 pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
405 }
406 pchip->pdata = pdata;
407
408 /* chip initialize */
409 rval = lm3630a_chip_init(pchip);
410 if (rval < 0) {
411 dev_err(&client->dev, "fail : init chip\n");
412 return rval;
413 }
414 /* backlight register */
415 rval = lm3630a_backlight_register(pchip);
416 if (rval < 0) {
417 dev_err(&client->dev, "fail : backlight register.\n");
418 return rval;
419 }
420 /* pwm */
421 if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
422 pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
423 if (IS_ERR(pchip->pwmd)) {
424 dev_err(&client->dev, "fail : get pwm device\n");
425 return PTR_ERR(pchip->pwmd);
426 }
427
428 /*
429 * FIXME: pwm_apply_args() should be removed when switching to
430 * the atomic PWM API.
431 */
432 pwm_apply_args(pchip->pwmd);
433 }
434
435 /* interrupt enable : irq 0 is not allowed */
436 pchip->irq = client->irq;
437 if (pchip->irq) {
438 rval = lm3630a_intr_config(pchip);
439 if (rval < 0)
440 return rval;
441 }
442 dev_info(&client->dev, "LM3630A backlight register OK.\n");
443 return 0;
444 }
445
lm3630a_remove(struct i2c_client * client)446 static int lm3630a_remove(struct i2c_client *client)
447 {
448 int rval;
449 struct lm3630a_chip *pchip = i2c_get_clientdata(client);
450
451 rval = lm3630a_write(pchip, REG_BRT_A, 0);
452 if (rval < 0)
453 dev_err(pchip->dev, "i2c failed to access register\n");
454
455 rval = lm3630a_write(pchip, REG_BRT_B, 0);
456 if (rval < 0)
457 dev_err(pchip->dev, "i2c failed to access register\n");
458
459 if (pchip->irq) {
460 free_irq(pchip->irq, pchip);
461 flush_workqueue(pchip->irqthread);
462 destroy_workqueue(pchip->irqthread);
463 }
464 return 0;
465 }
466
467 static const struct i2c_device_id lm3630a_id[] = {
468 {LM3630A_NAME, 0},
469 {}
470 };
471
472 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
473
474 static struct i2c_driver lm3630a_i2c_driver = {
475 .driver = {
476 .name = LM3630A_NAME,
477 },
478 .probe = lm3630a_probe,
479 .remove = lm3630a_remove,
480 .id_table = lm3630a_id,
481 };
482
483 module_i2c_driver(lm3630a_i2c_driver);
484
485 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
486 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
487 MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
488 MODULE_LICENSE("GPL v2");
489