leds-lm3530.c revision d5f33d45e4c0e306e8d16b4573891a65d9ad544f 
1/*
2 * Copyright (C) 2011 ST-Ericsson SA.
3 * Copyright (C) 2009 Motorola, Inc.
4 *
5 * License Terms: GNU General Public License v2
6 *
7 * Simple driver for National Semiconductor LM3530 Backlight driver chip
8 *
9 * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
10 * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
11 */
12
13#include <linux/i2c.h>
14#include <linux/leds.h>
15#include <linux/slab.h>
16#include <linux/platform_device.h>
17#include <linux/input.h>
18#include <linux/led-lm3530.h>
19#include <linux/types.h>
20
21#define LM3530_LED_DEV "lcd-backlight"
22#define LM3530_NAME "lm3530-led"
23
24#define LM3530_GEN_CONFIG		0x10
25#define LM3530_ALS_CONFIG		0x20
26#define LM3530_BRT_RAMP_RATE		0x30
27#define LM3530_ALS_ZONE_REG		0x40
28#define LM3530_ALS_IMP_SELECT		0x41
29#define LM3530_BRT_CTRL_REG		0xA0
30#define LM3530_ALS_ZB0_REG		0x60
31#define LM3530_ALS_ZB1_REG		0x61
32#define LM3530_ALS_ZB2_REG		0x62
33#define LM3530_ALS_ZB3_REG		0x63
34#define LM3530_ALS_Z0T_REG		0x70
35#define LM3530_ALS_Z1T_REG		0x71
36#define LM3530_ALS_Z2T_REG		0x72
37#define LM3530_ALS_Z3T_REG		0x73
38#define LM3530_ALS_Z4T_REG		0x74
39#define LM3530_REG_MAX			15
40
41/* General Control Register */
42#define LM3530_EN_I2C_SHIFT		(0)
43#define LM3530_RAMP_LAW_SHIFT		(1)
44#define LM3530_MAX_CURR_SHIFT		(2)
45#define LM3530_EN_PWM_SHIFT		(5)
46#define LM3530_PWM_POL_SHIFT		(6)
47#define LM3530_EN_PWM_SIMPLE_SHIFT	(7)
48
49#define LM3530_ENABLE_I2C		(1 << LM3530_EN_I2C_SHIFT)
50#define LM3530_ENABLE_PWM		(1 << LM3530_EN_PWM_SHIFT)
51#define LM3530_POL_LOW			(1 << LM3530_PWM_POL_SHIFT)
52#define LM3530_ENABLE_PWM_SIMPLE	(1 << LM3530_EN_PWM_SIMPLE_SHIFT)
53
54/* ALS Config Register Options */
55#define LM3530_ALS_AVG_TIME_SHIFT	(0)
56#define LM3530_EN_ALS_SHIFT		(3)
57#define LM3530_ALS_SEL_SHIFT		(5)
58
59#define LM3530_ENABLE_ALS		(3 << LM3530_EN_ALS_SHIFT)
60
61/* Brightness Ramp Rate Register */
62#define LM3530_BRT_RAMP_FALL_SHIFT	(0)
63#define LM3530_BRT_RAMP_RISE_SHIFT	(3)
64
65/* ALS Resistor Select */
66#define LM3530_ALS1_IMP_SHIFT		(0)
67#define LM3530_ALS2_IMP_SHIFT		(4)
68
69/* Zone Boundary Register defaults */
70#define LM3530_DEF_ZB_0			(0x33)
71#define LM3530_DEF_ZB_1			(0x66)
72#define LM3530_DEF_ZB_2			(0x99)
73#define LM3530_DEF_ZB_3			(0xCC)
74
75/* Zone Target Register defaults */
76#define LM3530_DEF_ZT_0			(0x19)
77#define LM3530_DEF_ZT_1			(0x33)
78#define LM3530_DEF_ZT_2			(0x4C)
79#define LM3530_DEF_ZT_3			(0x66)
80#define LM3530_DEF_ZT_4			(0x7F)
81
82struct lm3530_mode_map {
83	const char *mode;
84	enum lm3530_mode mode_val;
85};
86
87static struct lm3530_mode_map mode_map[] = {
88	{ "man", LM3530_BL_MODE_MANUAL },
89	{ "als", LM3530_BL_MODE_ALS },
90	{ "pwm", LM3530_BL_MODE_PWM },
91};
92
93/**
94 * struct lm3530_data
95 * @led_dev: led class device
96 * @client: i2c client
97 * @pdata: LM3530 platform data
98 * @mode: mode of operation - manual, ALS, PWM
99 */
100struct lm3530_data {
101	struct led_classdev led_dev;
102	struct i2c_client *client;
103	struct lm3530_platform_data *pdata;
104	enum lm3530_mode mode;
105};
106
107static const u8 lm3530_reg[LM3530_REG_MAX] = {
108	LM3530_GEN_CONFIG,
109	LM3530_ALS_CONFIG,
110	LM3530_BRT_RAMP_RATE,
111	LM3530_ALS_ZONE_REG,
112	LM3530_ALS_IMP_SELECT,
113	LM3530_BRT_CTRL_REG,
114	LM3530_ALS_ZB0_REG,
115	LM3530_ALS_ZB1_REG,
116	LM3530_ALS_ZB2_REG,
117	LM3530_ALS_ZB3_REG,
118	LM3530_ALS_Z0T_REG,
119	LM3530_ALS_Z1T_REG,
120	LM3530_ALS_Z2T_REG,
121	LM3530_ALS_Z3T_REG,
122	LM3530_ALS_Z4T_REG,
123};
124
125static int lm3530_get_mode_from_str(const char *str)
126{
127	int i;
128
129	for (i = 0; i < ARRAY_SIZE(mode_map); i++)
130		if (sysfs_streq(str, mode_map[i].mode))
131			return mode_map[i].mode_val;
132
133	return -1;
134}
135
136static int lm3530_init_registers(struct lm3530_data *drvdata)
137{
138	int ret = 0;
139	int i;
140	u8 gen_config;
141	u8 als_config = 0;
142	u8 brt_ramp;
143	u8 als_imp_sel = 0;
144	u8 brightness;
145	u8 reg_val[LM3530_REG_MAX];
146	struct lm3530_platform_data *pltfm = drvdata->pdata;
147	struct i2c_client *client = drvdata->client;
148
149	gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
150			((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
151
152	if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
153	    drvdata->mode == LM3530_BL_MODE_ALS)
154		gen_config |= (LM3530_ENABLE_I2C);
155
156	if (drvdata->mode == LM3530_BL_MODE_ALS) {
157		als_config =
158			(pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
159			(LM3530_ENABLE_ALS) |
160			(pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
161
162		als_imp_sel =
163			(pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
164			(pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
165	}
166
167	if (drvdata->mode == LM3530_BL_MODE_PWM)
168		gen_config |= (LM3530_ENABLE_PWM) |
169				(pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
170				(LM3530_ENABLE_PWM_SIMPLE);
171
172	brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
173			(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
174
175	brightness = pltfm->brt_val;
176
177	reg_val[0] = gen_config;	/* LM3530_GEN_CONFIG */
178	reg_val[1] = als_config;	/* LM3530_ALS_CONFIG */
179	reg_val[2] = brt_ramp;		/* LM3530_BRT_RAMP_RATE */
180	reg_val[3] = 0x00;		/* LM3530_ALS_ZONE_REG */
181	reg_val[4] = als_imp_sel;	/* LM3530_ALS_IMP_SELECT */
182	reg_val[5] = brightness;	/* LM3530_BRT_CTRL_REG */
183	reg_val[6] = LM3530_DEF_ZB_0;	/* LM3530_ALS_ZB0_REG */
184	reg_val[7] = LM3530_DEF_ZB_1;	/* LM3530_ALS_ZB1_REG */
185	reg_val[8] = LM3530_DEF_ZB_2;	/* LM3530_ALS_ZB2_REG */
186	reg_val[9] = LM3530_DEF_ZB_3;	/* LM3530_ALS_ZB3_REG */
187	reg_val[10] = LM3530_DEF_ZT_0;	/* LM3530_ALS_Z0T_REG */
188	reg_val[11] = LM3530_DEF_ZT_1;	/* LM3530_ALS_Z1T_REG */
189	reg_val[12] = LM3530_DEF_ZT_2;	/* LM3530_ALS_Z2T_REG */
190	reg_val[13] = LM3530_DEF_ZT_3;	/* LM3530_ALS_Z3T_REG */
191	reg_val[14] = LM3530_DEF_ZT_4;	/* LM3530_ALS_Z4T_REG */
192
193	for (i = 0; i < LM3530_REG_MAX; i++) {
194		ret = i2c_smbus_write_byte_data(client,
195				lm3530_reg[i], reg_val[i]);
196		if (ret)
197			break;
198	}
199
200	return ret;
201}
202
203static void lm3530_brightness_set(struct led_classdev *led_cdev,
204				     enum led_brightness brt_val)
205{
206	int err;
207	struct lm3530_data *drvdata =
208	    container_of(led_cdev, struct lm3530_data, led_dev);
209
210	switch (drvdata->mode) {
211	case LM3530_BL_MODE_MANUAL:
212
213		/* set the brightness in brightness control register*/
214		err = i2c_smbus_write_byte_data(drvdata->client,
215				LM3530_BRT_CTRL_REG, brt_val / 2);
216		if (err)
217			dev_err(&drvdata->client->dev,
218				"Unable to set brightness: %d\n", err);
219		break;
220	case LM3530_BL_MODE_ALS:
221		break;
222	case LM3530_BL_MODE_PWM:
223		break;
224	default:
225		break;
226	}
227}
228
229
230static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
231				   *attr, const char *buf, size_t size)
232{
233	int err;
234	struct i2c_client *client = container_of(
235					dev->parent, struct i2c_client, dev);
236	struct lm3530_data *drvdata = i2c_get_clientdata(client);
237	int mode;
238
239	mode = lm3530_get_mode_from_str(buf);
240	if (mode < 0) {
241		dev_err(dev, "Invalid mode\n");
242		return -EINVAL;
243	}
244
245	if (mode == LM3530_BL_MODE_MANUAL)
246		drvdata->mode = LM3530_BL_MODE_MANUAL;
247	else if (mode == LM3530_BL_MODE_ALS)
248		drvdata->mode = LM3530_BL_MODE_ALS;
249	else if (mode == LM3530_BL_MODE_PWM) {
250		dev_err(dev, "PWM mode not supported\n");
251		return -EINVAL;
252	}
253
254	err = lm3530_init_registers(drvdata);
255	if (err) {
256		dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
257		return err;
258	}
259
260	return sizeof(drvdata->mode);
261}
262
263static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);
264
265static int __devinit lm3530_probe(struct i2c_client *client,
266			   const struct i2c_device_id *id)
267{
268	struct lm3530_platform_data *pdata = client->dev.platform_data;
269	struct lm3530_data *drvdata;
270	int err = 0;
271
272	if (pdata == NULL) {
273		dev_err(&client->dev, "platform data required\n");
274		err = -ENODEV;
275		goto err_out;
276	}
277
278	/* BL mode */
279	if (pdata->mode > LM3530_BL_MODE_PWM) {
280		dev_err(&client->dev, "Illegal Mode request\n");
281		err = -EINVAL;
282		goto err_out;
283	}
284
285	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
286		dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
287		err = -EIO;
288		goto err_out;
289	}
290
291	drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
292	if (drvdata == NULL) {
293		err = -ENOMEM;
294		goto err_out;
295	}
296
297	drvdata->mode = pdata->mode;
298	drvdata->client = client;
299	drvdata->pdata = pdata;
300	drvdata->led_dev.name = LM3530_LED_DEV;
301	drvdata->led_dev.brightness_set = lm3530_brightness_set;
302
303	i2c_set_clientdata(client, drvdata);
304
305	err = lm3530_init_registers(drvdata);
306	if (err < 0) {
307		dev_err(&client->dev, "Register Init failed: %d\n", err);
308		err = -ENODEV;
309		goto err_reg_init;
310	}
311
312	err = led_classdev_register((struct device *)
313				      &client->dev, &drvdata->led_dev);
314	if (err < 0) {
315		dev_err(&client->dev, "Register led class failed: %d\n", err);
316		err = -ENODEV;
317		goto err_class_register;
318	}
319
320	err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
321	if (err < 0) {
322		dev_err(&client->dev, "File device creation failed: %d\n", err);
323		err = -ENODEV;
324		goto err_create_file;
325	}
326
327	return 0;
328
329err_create_file:
330	led_classdev_unregister(&drvdata->led_dev);
331err_class_register:
332err_reg_init:
333	kfree(drvdata);
334err_out:
335	return err;
336}
337
338static int __devexit lm3530_remove(struct i2c_client *client)
339{
340	struct lm3530_data *drvdata = i2c_get_clientdata(client);
341
342	device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
343	led_classdev_unregister(&drvdata->led_dev);
344	kfree(drvdata);
345	return 0;
346}
347
348static const struct i2c_device_id lm3530_id[] = {
349	{LM3530_NAME, 0},
350	{}
351};
352MODULE_DEVICE_TABLE(i2c, lm3530_id);
353
354static struct i2c_driver lm3530_i2c_driver = {
355	.probe = lm3530_probe,
356	.remove = lm3530_remove,
357	.id_table = lm3530_id,
358	.driver = {
359		.name = LM3530_NAME,
360		.owner = THIS_MODULE,
361	},
362};
363
364static int __init lm3530_init(void)
365{
366	return i2c_add_driver(&lm3530_i2c_driver);
367}
368
369static void __exit lm3530_exit(void)
370{
371	i2c_del_driver(&lm3530_i2c_driver);
372}
373
374module_init(lm3530_init);
375module_exit(lm3530_exit);
376
377MODULE_DESCRIPTION("Back Light driver for LM3530");
378MODULE_LICENSE("GPL v2");
379MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
380