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
37struct 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 */
51static 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, &reg_val);
57	if (rval < 0)
58		return rval;
59	return reg_val & 0xFF;
60}
61
62static 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
68static 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 */
76static 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 */
106static 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
123static 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
139static 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
163static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
164{
165	unsigned int period = pwm_get_period(pchip->pwmd);
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 */
176static 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
205out_i2c_err:
206	dev_err(pchip->dev, "i2c failed to access\n");
207	return bl->props.brightness;
208}
209
210static 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
238out:
239	bl->props.brightness = brightness;
240	return bl->props.brightness;
241out_i2c_err:
242	dev_err(pchip->dev, "i2c failed to access register\n");
243	return 0;
244}
245
246static 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 */
253static 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
282out_i2c_err:
283	dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
284	return bl->props.brightness;
285}
286
287static 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
315out:
316	bl->props.brightness = brightness;
317	return bl->props.brightness;
318out_i2c_err:
319	dev_err(pchip->dev, "i2c failed to access register\n");
320	return 0;
321}
322
323static 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
329static 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
360static const struct regmap_config lm3630a_regmap = {
361	.reg_bits = 8,
362	.val_bits = 8,
363	.max_register = REG_MAX,
364};
365
366static 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	pchip->pwmd->period = pdata->pwm_period;
429
430	/* interrupt enable  : irq 0 is not allowed */
431	pchip->irq = client->irq;
432	if (pchip->irq) {
433		rval = lm3630a_intr_config(pchip);
434		if (rval < 0)
435			return rval;
436	}
437	dev_info(&client->dev, "LM3630A backlight register OK.\n");
438	return 0;
439}
440
441static int lm3630a_remove(struct i2c_client *client)
442{
443	int rval;
444	struct lm3630a_chip *pchip = i2c_get_clientdata(client);
445
446	rval = lm3630a_write(pchip, REG_BRT_A, 0);
447	if (rval < 0)
448		dev_err(pchip->dev, "i2c failed to access register\n");
449
450	rval = lm3630a_write(pchip, REG_BRT_B, 0);
451	if (rval < 0)
452		dev_err(pchip->dev, "i2c failed to access register\n");
453
454	if (pchip->irq) {
455		free_irq(pchip->irq, pchip);
456		flush_workqueue(pchip->irqthread);
457		destroy_workqueue(pchip->irqthread);
458	}
459	return 0;
460}
461
462static const struct i2c_device_id lm3630a_id[] = {
463	{LM3630A_NAME, 0},
464	{}
465};
466
467MODULE_DEVICE_TABLE(i2c, lm3630a_id);
468
469static struct i2c_driver lm3630a_i2c_driver = {
470	.driver = {
471		   .name = LM3630A_NAME,
472		   },
473	.probe = lm3630a_probe,
474	.remove = lm3630a_remove,
475	.id_table = lm3630a_id,
476};
477
478module_i2c_driver(lm3630a_i2c_driver);
479
480MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
481MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
482MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
483MODULE_LICENSE("GPL v2");
484