1/*
2* Simple driver for Texas Instruments LM3642 LED Flash 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/delay.h>
12#include <linux/i2c.h>
13#include <linux/leds.h>
14#include <linux/slab.h>
15#include <linux/platform_device.h>
16#include <linux/fs.h>
17#include <linux/regmap.h>
18#include <linux/workqueue.h>
19#include <linux/platform_data/leds-lm3642.h>
20
21#define	REG_FILT_TIME			(0x0)
22#define	REG_IVFM_MODE			(0x1)
23#define	REG_TORCH_TIME			(0x6)
24#define	REG_FLASH			(0x8)
25#define	REG_I_CTRL			(0x9)
26#define	REG_ENABLE			(0xA)
27#define	REG_FLAG			(0xB)
28#define	REG_MAX				(0xB)
29
30#define	UVLO_EN_SHIFT			(7)
31#define	IVM_D_TH_SHIFT			(2)
32#define	TORCH_RAMP_UP_TIME_SHIFT	(3)
33#define	TORCH_RAMP_DN_TIME_SHIFT	(0)
34#define	INDUCTOR_I_LIMIT_SHIFT		(6)
35#define	FLASH_RAMP_TIME_SHIFT		(3)
36#define	FLASH_TOUT_TIME_SHIFT		(0)
37#define	TORCH_I_SHIFT			(4)
38#define	FLASH_I_SHIFT			(0)
39#define	IVFM_SHIFT			(7)
40#define	TX_PIN_EN_SHIFT			(6)
41#define	STROBE_PIN_EN_SHIFT		(5)
42#define	TORCH_PIN_EN_SHIFT		(4)
43#define	MODE_BITS_SHIFT			(0)
44
45#define	UVLO_EN_MASK			(0x1)
46#define	IVM_D_TH_MASK			(0x7)
47#define	TORCH_RAMP_UP_TIME_MASK		(0x7)
48#define	TORCH_RAMP_DN_TIME_MASK		(0x7)
49#define	INDUCTOR_I_LIMIT_MASK		(0x1)
50#define	FLASH_RAMP_TIME_MASK		(0x7)
51#define	FLASH_TOUT_TIME_MASK		(0x7)
52#define	TORCH_I_MASK			(0x7)
53#define	FLASH_I_MASK			(0xF)
54#define	IVFM_MASK			(0x1)
55#define	TX_PIN_EN_MASK			(0x1)
56#define	STROBE_PIN_EN_MASK		(0x1)
57#define	TORCH_PIN_EN_MASK		(0x1)
58#define	MODE_BITS_MASK			(0x73)
59#define EX_PIN_CONTROL_MASK		(0x71)
60#define EX_PIN_ENABLE_MASK		(0x70)
61
62enum lm3642_mode {
63	MODES_STASNDBY = 0,
64	MODES_INDIC,
65	MODES_TORCH,
66	MODES_FLASH
67};
68
69struct lm3642_chip_data {
70	struct device *dev;
71
72	struct led_classdev cdev_flash;
73	struct led_classdev cdev_torch;
74	struct led_classdev cdev_indicator;
75
76	struct work_struct work_flash;
77	struct work_struct work_torch;
78	struct work_struct work_indicator;
79
80	u8 br_flash;
81	u8 br_torch;
82	u8 br_indicator;
83
84	enum lm3642_torch_pin_enable torch_pin;
85	enum lm3642_strobe_pin_enable strobe_pin;
86	enum lm3642_tx_pin_enable tx_pin;
87
88	struct lm3642_platform_data *pdata;
89	struct regmap *regmap;
90	struct mutex lock;
91
92	unsigned int last_flag;
93};
94
95/* chip initialize */
96static int lm3642_chip_init(struct lm3642_chip_data *chip)
97{
98	int ret;
99	struct lm3642_platform_data *pdata = chip->pdata;
100
101	/* set enable register */
102	ret = regmap_update_bits(chip->regmap, REG_ENABLE, EX_PIN_ENABLE_MASK,
103				 pdata->tx_pin);
104	if (ret < 0)
105		dev_err(chip->dev, "Failed to update REG_ENABLE Register\n");
106	return ret;
107}
108
109/* chip control */
110static int lm3642_control(struct lm3642_chip_data *chip,
111			  u8 brightness, enum lm3642_mode opmode)
112{
113	int ret;
114
115	ret = regmap_read(chip->regmap, REG_FLAG, &chip->last_flag);
116	if (ret < 0) {
117		dev_err(chip->dev, "Failed to read REG_FLAG Register\n");
118		goto out;
119	}
120
121	if (chip->last_flag)
122		dev_info(chip->dev, "Last FLAG is 0x%x\n", chip->last_flag);
123
124	/* brightness 0 means off-state */
125	if (!brightness)
126		opmode = MODES_STASNDBY;
127
128	switch (opmode) {
129	case MODES_TORCH:
130		ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
131					 TORCH_I_MASK << TORCH_I_SHIFT,
132					 (brightness - 1) << TORCH_I_SHIFT);
133
134		if (chip->torch_pin)
135			opmode |= (TORCH_PIN_EN_MASK << TORCH_PIN_EN_SHIFT);
136		break;
137
138	case MODES_FLASH:
139		ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
140					 FLASH_I_MASK << FLASH_I_SHIFT,
141					 (brightness - 1) << FLASH_I_SHIFT);
142
143		if (chip->strobe_pin)
144			opmode |= (STROBE_PIN_EN_MASK << STROBE_PIN_EN_SHIFT);
145		break;
146
147	case MODES_INDIC:
148		ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
149					 TORCH_I_MASK << TORCH_I_SHIFT,
150					 (brightness - 1) << TORCH_I_SHIFT);
151		break;
152
153	case MODES_STASNDBY:
154
155		break;
156
157	default:
158		return ret;
159	}
160	if (ret < 0) {
161		dev_err(chip->dev, "Failed to write REG_I_CTRL Register\n");
162		goto out;
163	}
164
165	if (chip->tx_pin)
166		opmode |= (TX_PIN_EN_MASK << TX_PIN_EN_SHIFT);
167
168	ret = regmap_update_bits(chip->regmap, REG_ENABLE,
169				 MODE_BITS_MASK << MODE_BITS_SHIFT,
170				 opmode << MODE_BITS_SHIFT);
171out:
172	return ret;
173}
174
175/* torch */
176
177/* torch pin config for lm3642*/
178static ssize_t lm3642_torch_pin_store(struct device *dev,
179				      struct device_attribute *attr,
180				      const char *buf, size_t size)
181{
182	ssize_t ret;
183	struct led_classdev *led_cdev = dev_get_drvdata(dev);
184	struct lm3642_chip_data *chip =
185	    container_of(led_cdev, struct lm3642_chip_data, cdev_indicator);
186	unsigned int state;
187
188	ret = kstrtouint(buf, 10, &state);
189	if (ret)
190		goto out_strtoint;
191	if (state != 0)
192		state = 0x01 << TORCH_PIN_EN_SHIFT;
193
194	chip->torch_pin = state;
195	ret = regmap_update_bits(chip->regmap, REG_ENABLE,
196				 TORCH_PIN_EN_MASK << TORCH_PIN_EN_SHIFT,
197				 state);
198	if (ret < 0)
199		goto out;
200
201	return size;
202out:
203	dev_err(chip->dev, "%s:i2c access fail to register\n", __func__);
204	return ret;
205out_strtoint:
206	dev_err(chip->dev, "%s: fail to change str to int\n", __func__);
207	return ret;
208}
209
210static DEVICE_ATTR(torch_pin, S_IWUSR, NULL, lm3642_torch_pin_store);
211
212static void lm3642_deferred_torch_brightness_set(struct work_struct *work)
213{
214	struct lm3642_chip_data *chip =
215	    container_of(work, struct lm3642_chip_data, work_torch);
216
217	mutex_lock(&chip->lock);
218	lm3642_control(chip, chip->br_torch, MODES_TORCH);
219	mutex_unlock(&chip->lock);
220}
221
222static void lm3642_torch_brightness_set(struct led_classdev *cdev,
223					enum led_brightness brightness)
224{
225	struct lm3642_chip_data *chip =
226	    container_of(cdev, struct lm3642_chip_data, cdev_torch);
227
228	chip->br_torch = brightness;
229	schedule_work(&chip->work_torch);
230}
231
232/* flash */
233
234/* strobe pin config for lm3642*/
235static ssize_t lm3642_strobe_pin_store(struct device *dev,
236				       struct device_attribute *attr,
237				       const char *buf, size_t size)
238{
239	ssize_t ret;
240	struct led_classdev *led_cdev = dev_get_drvdata(dev);
241	struct lm3642_chip_data *chip =
242	    container_of(led_cdev, struct lm3642_chip_data, cdev_indicator);
243	unsigned int state;
244
245	ret = kstrtouint(buf, 10, &state);
246	if (ret)
247		goto out_strtoint;
248	if (state != 0)
249		state = 0x01 << STROBE_PIN_EN_SHIFT;
250
251	chip->strobe_pin = state;
252	ret = regmap_update_bits(chip->regmap, REG_ENABLE,
253				 STROBE_PIN_EN_MASK << STROBE_PIN_EN_SHIFT,
254				 state);
255	if (ret < 0)
256		goto out;
257
258	return size;
259out:
260	dev_err(chip->dev, "%s:i2c access fail to register\n", __func__);
261	return ret;
262out_strtoint:
263	dev_err(chip->dev, "%s: fail to change str to int\n", __func__);
264	return ret;
265}
266
267static DEVICE_ATTR(strobe_pin, S_IWUSR, NULL, lm3642_strobe_pin_store);
268
269static void lm3642_deferred_strobe_brightness_set(struct work_struct *work)
270{
271	struct lm3642_chip_data *chip =
272	    container_of(work, struct lm3642_chip_data, work_flash);
273
274	mutex_lock(&chip->lock);
275	lm3642_control(chip, chip->br_flash, MODES_FLASH);
276	mutex_unlock(&chip->lock);
277}
278
279static void lm3642_strobe_brightness_set(struct led_classdev *cdev,
280					 enum led_brightness brightness)
281{
282	struct lm3642_chip_data *chip =
283	    container_of(cdev, struct lm3642_chip_data, cdev_flash);
284
285	chip->br_flash = brightness;
286	schedule_work(&chip->work_flash);
287}
288
289/* indicator */
290static void lm3642_deferred_indicator_brightness_set(struct work_struct *work)
291{
292	struct lm3642_chip_data *chip =
293	    container_of(work, struct lm3642_chip_data, work_indicator);
294
295	mutex_lock(&chip->lock);
296	lm3642_control(chip, chip->br_indicator, MODES_INDIC);
297	mutex_unlock(&chip->lock);
298}
299
300static void lm3642_indicator_brightness_set(struct led_classdev *cdev,
301					    enum led_brightness brightness)
302{
303	struct lm3642_chip_data *chip =
304	    container_of(cdev, struct lm3642_chip_data, cdev_indicator);
305
306	chip->br_indicator = brightness;
307	schedule_work(&chip->work_indicator);
308}
309
310static const struct regmap_config lm3642_regmap = {
311	.reg_bits = 8,
312	.val_bits = 8,
313	.max_register = REG_MAX,
314};
315
316static struct attribute *lm3642_flash_attrs[] = {
317	&dev_attr_strobe_pin.attr,
318	NULL
319};
320ATTRIBUTE_GROUPS(lm3642_flash);
321
322static struct attribute *lm3642_torch_attrs[] = {
323	&dev_attr_torch_pin.attr,
324	NULL
325};
326ATTRIBUTE_GROUPS(lm3642_torch);
327
328static int lm3642_probe(struct i2c_client *client,
329				  const struct i2c_device_id *id)
330{
331	struct lm3642_platform_data *pdata = dev_get_platdata(&client->dev);
332	struct lm3642_chip_data *chip;
333
334	int err;
335
336	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
337		dev_err(&client->dev, "i2c functionality check fail.\n");
338		return -EOPNOTSUPP;
339	}
340
341	if (pdata == NULL) {
342		dev_err(&client->dev, "needs Platform Data.\n");
343		return -ENODATA;
344	}
345
346	chip = devm_kzalloc(&client->dev,
347			    sizeof(struct lm3642_chip_data), GFP_KERNEL);
348	if (!chip)
349		return -ENOMEM;
350
351	chip->dev = &client->dev;
352	chip->pdata = pdata;
353
354	chip->tx_pin = pdata->tx_pin;
355	chip->torch_pin = pdata->torch_pin;
356	chip->strobe_pin = pdata->strobe_pin;
357
358	chip->regmap = devm_regmap_init_i2c(client, &lm3642_regmap);
359	if (IS_ERR(chip->regmap)) {
360		err = PTR_ERR(chip->regmap);
361		dev_err(&client->dev, "Failed to allocate register map: %d\n",
362			err);
363		return err;
364	}
365
366	mutex_init(&chip->lock);
367	i2c_set_clientdata(client, chip);
368
369	err = lm3642_chip_init(chip);
370	if (err < 0)
371		goto err_out;
372
373	/* flash */
374	INIT_WORK(&chip->work_flash, lm3642_deferred_strobe_brightness_set);
375	chip->cdev_flash.name = "flash";
376	chip->cdev_flash.max_brightness = 16;
377	chip->cdev_flash.brightness_set = lm3642_strobe_brightness_set;
378	chip->cdev_flash.default_trigger = "flash";
379	chip->cdev_flash.groups = lm3642_flash_groups,
380	err = led_classdev_register((struct device *)
381				    &client->dev, &chip->cdev_flash);
382	if (err < 0) {
383		dev_err(chip->dev, "failed to register flash\n");
384		goto err_out;
385	}
386
387	/* torch */
388	INIT_WORK(&chip->work_torch, lm3642_deferred_torch_brightness_set);
389	chip->cdev_torch.name = "torch";
390	chip->cdev_torch.max_brightness = 8;
391	chip->cdev_torch.brightness_set = lm3642_torch_brightness_set;
392	chip->cdev_torch.default_trigger = "torch";
393	chip->cdev_torch.groups = lm3642_torch_groups,
394	err = led_classdev_register((struct device *)
395				    &client->dev, &chip->cdev_torch);
396	if (err < 0) {
397		dev_err(chip->dev, "failed to register torch\n");
398		goto err_create_torch_file;
399	}
400
401	/* indicator */
402	INIT_WORK(&chip->work_indicator,
403		  lm3642_deferred_indicator_brightness_set);
404	chip->cdev_indicator.name = "indicator";
405	chip->cdev_indicator.max_brightness = 8;
406	chip->cdev_indicator.brightness_set = lm3642_indicator_brightness_set;
407	err = led_classdev_register((struct device *)
408				    &client->dev, &chip->cdev_indicator);
409	if (err < 0) {
410		dev_err(chip->dev, "failed to register indicator\n");
411		goto err_create_indicator_file;
412	}
413
414	dev_info(&client->dev, "LM3642 is initialized\n");
415	return 0;
416
417err_create_indicator_file:
418	led_classdev_unregister(&chip->cdev_torch);
419err_create_torch_file:
420	led_classdev_unregister(&chip->cdev_flash);
421err_out:
422	return err;
423}
424
425static int lm3642_remove(struct i2c_client *client)
426{
427	struct lm3642_chip_data *chip = i2c_get_clientdata(client);
428
429	led_classdev_unregister(&chip->cdev_indicator);
430	flush_work(&chip->work_indicator);
431	led_classdev_unregister(&chip->cdev_torch);
432	flush_work(&chip->work_torch);
433	led_classdev_unregister(&chip->cdev_flash);
434	flush_work(&chip->work_flash);
435	regmap_write(chip->regmap, REG_ENABLE, 0);
436	return 0;
437}
438
439static const struct i2c_device_id lm3642_id[] = {
440	{LM3642_NAME, 0},
441	{}
442};
443
444MODULE_DEVICE_TABLE(i2c, lm3642_id);
445
446static struct i2c_driver lm3642_i2c_driver = {
447	.driver = {
448		   .name = LM3642_NAME,
449		   .owner = THIS_MODULE,
450		   .pm = NULL,
451		   },
452	.probe = lm3642_probe,
453	.remove = lm3642_remove,
454	.id_table = lm3642_id,
455};
456
457module_i2c_driver(lm3642_i2c_driver);
458
459MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3642");
460MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
461MODULE_AUTHOR("G.Shark Jeong <gshark.jeong@gmail.com>");
462MODULE_LICENSE("GPL v2");
463