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Shreshtha Kumar Sahub1e6b702011-03-22 16:30:16 -07001/*
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};
Axel Lind5f33d42011-05-17 15:44:09 -0700352MODULE_DEVICE_TABLE(i2c, lm3530_id);
Shreshtha Kumar Sahub1e6b702011-03-22 16:30:16 -0700353
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>");