2 * Copyright (C) 2011 ST-Ericsson SA.
3 * Copyright (C) 2009 Motorola, Inc.
5 * License Terms: GNU General Public License v2
7 * Simple driver for National Semiconductor LM3530 Backlight driver chip
9 * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
10 * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
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 #include <linux/regulator/consumer.h>
21 #include <linux/module.h>
23 #define LM3530_LED_DEV "lcd-backlight"
24 #define LM3530_NAME "lm3530-led"
26 #define LM3530_GEN_CONFIG 0x10
27 #define LM3530_ALS_CONFIG 0x20
28 #define LM3530_BRT_RAMP_RATE 0x30
29 #define LM3530_ALS_IMP_SELECT 0x41
30 #define LM3530_BRT_CTRL_REG 0xA0
31 #define LM3530_ALS_ZB0_REG 0x60
32 #define LM3530_ALS_ZB1_REG 0x61
33 #define LM3530_ALS_ZB2_REG 0x62
34 #define LM3530_ALS_ZB3_REG 0x63
35 #define LM3530_ALS_Z0T_REG 0x70
36 #define LM3530_ALS_Z1T_REG 0x71
37 #define LM3530_ALS_Z2T_REG 0x72
38 #define LM3530_ALS_Z3T_REG 0x73
39 #define LM3530_ALS_Z4T_REG 0x74
40 #define LM3530_REG_MAX 14
42 /* General Control Register */
43 #define LM3530_EN_I2C_SHIFT (0)
44 #define LM3530_RAMP_LAW_SHIFT (1)
45 #define LM3530_MAX_CURR_SHIFT (2)
46 #define LM3530_EN_PWM_SHIFT (5)
47 #define LM3530_PWM_POL_SHIFT (6)
48 #define LM3530_EN_PWM_SIMPLE_SHIFT (7)
50 #define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT)
51 #define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT)
52 #define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT)
53 #define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
55 /* ALS Config Register Options */
56 #define LM3530_ALS_AVG_TIME_SHIFT (0)
57 #define LM3530_EN_ALS_SHIFT (3)
58 #define LM3530_ALS_SEL_SHIFT (5)
60 #define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT)
62 /* Brightness Ramp Rate Register */
63 #define LM3530_BRT_RAMP_FALL_SHIFT (0)
64 #define LM3530_BRT_RAMP_RISE_SHIFT (3)
66 /* ALS Resistor Select */
67 #define LM3530_ALS1_IMP_SHIFT (0)
68 #define LM3530_ALS2_IMP_SHIFT (4)
70 /* Zone Boundary Register defaults */
71 #define LM3530_ALS_ZB_MAX (4)
72 #define LM3530_ALS_WINDOW_mV (1000)
73 #define LM3530_ALS_OFFSET_mV (4)
75 /* Zone Target Register defaults */
76 #define LM3530_DEF_ZT_0 (0x7F)
77 #define LM3530_DEF_ZT_1 (0x66)
78 #define LM3530_DEF_ZT_2 (0x4C)
79 #define LM3530_DEF_ZT_3 (0x33)
80 #define LM3530_DEF_ZT_4 (0x19)
82 /* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
83 #define MAX_BRIGHTNESS (127)
85 struct lm3530_mode_map
{
87 enum lm3530_mode mode_val
;
90 static struct lm3530_mode_map mode_map
[] = {
91 { "man", LM3530_BL_MODE_MANUAL
},
92 { "als", LM3530_BL_MODE_ALS
},
93 { "pwm", LM3530_BL_MODE_PWM
},
98 * @led_dev: led class device
100 * @pdata: LM3530 platform data
101 * @mode: mode of operation - manual, ALS, PWM
102 * @regulator: regulator
103 * @brighness: previous brightness value
104 * @enable: regulator is enabled
107 struct led_classdev led_dev
;
108 struct i2c_client
*client
;
109 struct lm3530_platform_data
*pdata
;
110 enum lm3530_mode mode
;
111 struct regulator
*regulator
;
112 enum led_brightness brightness
;
116 static const u8 lm3530_reg
[LM3530_REG_MAX
] = {
119 LM3530_BRT_RAMP_RATE
,
120 LM3530_ALS_IMP_SELECT
,
133 static int lm3530_get_mode_from_str(const char *str
)
137 for (i
= 0; i
< ARRAY_SIZE(mode_map
); i
++)
138 if (sysfs_streq(str
, mode_map
[i
].mode
))
139 return mode_map
[i
].mode_val
;
144 static int lm3530_init_registers(struct lm3530_data
*drvdata
)
153 u8 reg_val
[LM3530_REG_MAX
];
154 u8 zones
[LM3530_ALS_ZB_MAX
];
155 u32 als_vmin
, als_vmax
, als_vstep
;
156 struct lm3530_platform_data
*pltfm
= drvdata
->pdata
;
157 struct i2c_client
*client
= drvdata
->client
;
158 struct lm3530_pwm_data
*pwm
= &pltfm
->pwm_data
;
160 gen_config
= (pltfm
->brt_ramp_law
<< LM3530_RAMP_LAW_SHIFT
) |
161 ((pltfm
->max_current
& 7) << LM3530_MAX_CURR_SHIFT
);
163 if (drvdata
->mode
== LM3530_BL_MODE_MANUAL
||
164 drvdata
->mode
== LM3530_BL_MODE_ALS
)
165 gen_config
|= (LM3530_ENABLE_I2C
);
167 if (drvdata
->mode
== LM3530_BL_MODE_ALS
) {
168 if (pltfm
->als_vmax
== 0) {
170 pltfm
->als_vmax
= LM3530_ALS_WINDOW_mV
;
173 als_vmin
= pltfm
->als_vmin
;
174 als_vmax
= pltfm
->als_vmax
;
176 if ((als_vmax
- als_vmin
) > LM3530_ALS_WINDOW_mV
)
177 pltfm
->als_vmax
= als_vmax
=
178 als_vmin
+ LM3530_ALS_WINDOW_mV
;
180 /* n zone boundary makes n+1 zones */
181 als_vstep
= (als_vmax
- als_vmin
) / (LM3530_ALS_ZB_MAX
+ 1);
183 for (i
= 0; i
< LM3530_ALS_ZB_MAX
; i
++)
184 zones
[i
] = (((als_vmin
+ LM3530_ALS_OFFSET_mV
) +
185 als_vstep
+ (i
* als_vstep
)) * LED_FULL
)
189 (pltfm
->als_avrg_time
<< LM3530_ALS_AVG_TIME_SHIFT
) |
190 (LM3530_ENABLE_ALS
) |
191 (pltfm
->als_input_mode
<< LM3530_ALS_SEL_SHIFT
);
194 (pltfm
->als1_resistor_sel
<< LM3530_ALS1_IMP_SHIFT
) |
195 (pltfm
->als2_resistor_sel
<< LM3530_ALS2_IMP_SHIFT
);
199 if (drvdata
->mode
== LM3530_BL_MODE_PWM
)
200 gen_config
|= (LM3530_ENABLE_PWM
) |
201 (pltfm
->pwm_pol_hi
<< LM3530_PWM_POL_SHIFT
) |
202 (LM3530_ENABLE_PWM_SIMPLE
);
204 brt_ramp
= (pltfm
->brt_ramp_fall
<< LM3530_BRT_RAMP_FALL_SHIFT
) |
205 (pltfm
->brt_ramp_rise
<< LM3530_BRT_RAMP_RISE_SHIFT
);
207 if (drvdata
->brightness
)
208 brightness
= drvdata
->brightness
;
210 brightness
= drvdata
->brightness
= pltfm
->brt_val
;
212 if (brightness
> drvdata
->led_dev
.max_brightness
)
213 brightness
= drvdata
->led_dev
.max_brightness
;
215 reg_val
[0] = gen_config
; /* LM3530_GEN_CONFIG */
216 reg_val
[1] = als_config
; /* LM3530_ALS_CONFIG */
217 reg_val
[2] = brt_ramp
; /* LM3530_BRT_RAMP_RATE */
218 reg_val
[3] = als_imp_sel
; /* LM3530_ALS_IMP_SELECT */
219 reg_val
[4] = brightness
; /* LM3530_BRT_CTRL_REG */
220 reg_val
[5] = zones
[0]; /* LM3530_ALS_ZB0_REG */
221 reg_val
[6] = zones
[1]; /* LM3530_ALS_ZB1_REG */
222 reg_val
[7] = zones
[2]; /* LM3530_ALS_ZB2_REG */
223 reg_val
[8] = zones
[3]; /* LM3530_ALS_ZB3_REG */
224 reg_val
[9] = LM3530_DEF_ZT_0
; /* LM3530_ALS_Z0T_REG */
225 reg_val
[10] = LM3530_DEF_ZT_1
; /* LM3530_ALS_Z1T_REG */
226 reg_val
[11] = LM3530_DEF_ZT_2
; /* LM3530_ALS_Z2T_REG */
227 reg_val
[12] = LM3530_DEF_ZT_3
; /* LM3530_ALS_Z3T_REG */
228 reg_val
[13] = LM3530_DEF_ZT_4
; /* LM3530_ALS_Z4T_REG */
230 if (!drvdata
->enable
) {
231 ret
= regulator_enable(drvdata
->regulator
);
233 dev_err(&drvdata
->client
->dev
,
234 "Enable regulator failed\n");
237 drvdata
->enable
= true;
240 for (i
= 0; i
< LM3530_REG_MAX
; i
++) {
241 /* do not update brightness register when pwm mode */
242 if (lm3530_reg
[i
] == LM3530_BRT_CTRL_REG
&&
243 drvdata
->mode
== LM3530_BL_MODE_PWM
) {
244 if (pwm
->pwm_set_intensity
)
245 pwm
->pwm_set_intensity(reg_val
[i
],
246 drvdata
->led_dev
.max_brightness
);
250 ret
= i2c_smbus_write_byte_data(client
,
251 lm3530_reg
[i
], reg_val
[i
]);
259 static void lm3530_brightness_set(struct led_classdev
*led_cdev
,
260 enum led_brightness brt_val
)
263 struct lm3530_data
*drvdata
=
264 container_of(led_cdev
, struct lm3530_data
, led_dev
);
265 struct lm3530_platform_data
*pdata
= drvdata
->pdata
;
266 struct lm3530_pwm_data
*pwm
= &pdata
->pwm_data
;
267 u8 max_brightness
= led_cdev
->max_brightness
;
269 switch (drvdata
->mode
) {
270 case LM3530_BL_MODE_MANUAL
:
272 if (!drvdata
->enable
) {
273 err
= lm3530_init_registers(drvdata
);
275 dev_err(&drvdata
->client
->dev
,
276 "Register Init failed: %d\n", err
);
281 /* set the brightness in brightness control register*/
282 err
= i2c_smbus_write_byte_data(drvdata
->client
,
283 LM3530_BRT_CTRL_REG
, brt_val
);
285 dev_err(&drvdata
->client
->dev
,
286 "Unable to set brightness: %d\n", err
);
288 drvdata
->brightness
= brt_val
;
291 err
= regulator_disable(drvdata
->regulator
);
293 dev_err(&drvdata
->client
->dev
,
294 "Disable regulator failed\n");
295 drvdata
->enable
= false;
298 case LM3530_BL_MODE_ALS
:
300 case LM3530_BL_MODE_PWM
:
301 if (pwm
->pwm_set_intensity
)
302 pwm
->pwm_set_intensity(brt_val
, max_brightness
);
309 static ssize_t
lm3530_mode_get(struct device
*dev
,
310 struct device_attribute
*attr
, char *buf
)
312 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
313 struct lm3530_data
*drvdata
;
316 drvdata
= container_of(led_cdev
, struct lm3530_data
, led_dev
);
317 for (i
= 0; i
< ARRAY_SIZE(mode_map
); i
++)
318 if (drvdata
->mode
== mode_map
[i
].mode_val
)
319 len
+= sprintf(buf
+ len
, "[%s] ", mode_map
[i
].mode
);
321 len
+= sprintf(buf
+ len
, "%s ", mode_map
[i
].mode
);
323 len
+= sprintf(buf
+ len
, "\n");
328 static ssize_t
lm3530_mode_set(struct device
*dev
, struct device_attribute
329 *attr
, const char *buf
, size_t size
)
331 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
332 struct lm3530_data
*drvdata
;
333 struct lm3530_pwm_data
*pwm
;
337 drvdata
= container_of(led_cdev
, struct lm3530_data
, led_dev
);
338 pwm
= &drvdata
->pdata
->pwm_data
;
339 max_brightness
= led_cdev
->max_brightness
;
340 mode
= lm3530_get_mode_from_str(buf
);
342 dev_err(dev
, "Invalid mode\n");
346 drvdata
->mode
= mode
;
348 /* set pwm to low if unnecessary */
349 if (mode
!= LM3530_BL_MODE_PWM
&& pwm
->pwm_set_intensity
)
350 pwm
->pwm_set_intensity(0, max_brightness
);
352 err
= lm3530_init_registers(drvdata
);
354 dev_err(dev
, "Setting %s Mode failed :%d\n", buf
, err
);
358 return sizeof(drvdata
->mode
);
360 static DEVICE_ATTR(mode
, 0644, lm3530_mode_get
, lm3530_mode_set
);
362 static int __devinit
lm3530_probe(struct i2c_client
*client
,
363 const struct i2c_device_id
*id
)
365 struct lm3530_platform_data
*pdata
= client
->dev
.platform_data
;
366 struct lm3530_data
*drvdata
;
370 dev_err(&client
->dev
, "platform data required\n");
376 if (pdata
->mode
> LM3530_BL_MODE_PWM
) {
377 dev_err(&client
->dev
, "Illegal Mode request\n");
382 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
)) {
383 dev_err(&client
->dev
, "I2C_FUNC_I2C not supported\n");
388 drvdata
= kzalloc(sizeof(struct lm3530_data
), GFP_KERNEL
);
389 if (drvdata
== NULL
) {
394 drvdata
->mode
= pdata
->mode
;
395 drvdata
->client
= client
;
396 drvdata
->pdata
= pdata
;
397 drvdata
->brightness
= LED_OFF
;
398 drvdata
->enable
= false;
399 drvdata
->led_dev
.name
= LM3530_LED_DEV
;
400 drvdata
->led_dev
.brightness_set
= lm3530_brightness_set
;
401 drvdata
->led_dev
.max_brightness
= MAX_BRIGHTNESS
;
403 i2c_set_clientdata(client
, drvdata
);
405 drvdata
->regulator
= regulator_get(&client
->dev
, "vin");
406 if (IS_ERR(drvdata
->regulator
)) {
407 dev_err(&client
->dev
, "regulator get failed\n");
408 err
= PTR_ERR(drvdata
->regulator
);
409 drvdata
->regulator
= NULL
;
410 goto err_regulator_get
;
413 if (drvdata
->pdata
->brt_val
) {
414 err
= lm3530_init_registers(drvdata
);
416 dev_err(&client
->dev
,
417 "Register Init failed: %d\n", err
);
422 err
= led_classdev_register(&client
->dev
, &drvdata
->led_dev
);
424 dev_err(&client
->dev
, "Register led class failed: %d\n", err
);
426 goto err_class_register
;
429 err
= device_create_file(drvdata
->led_dev
.dev
, &dev_attr_mode
);
431 dev_err(&client
->dev
, "File device creation failed: %d\n", err
);
433 goto err_create_file
;
439 led_classdev_unregister(&drvdata
->led_dev
);
442 regulator_put(drvdata
->regulator
);
449 static int __devexit
lm3530_remove(struct i2c_client
*client
)
451 struct lm3530_data
*drvdata
= i2c_get_clientdata(client
);
453 device_remove_file(drvdata
->led_dev
.dev
, &dev_attr_mode
);
456 regulator_disable(drvdata
->regulator
);
457 regulator_put(drvdata
->regulator
);
458 led_classdev_unregister(&drvdata
->led_dev
);
463 static const struct i2c_device_id lm3530_id
[] = {
467 MODULE_DEVICE_TABLE(i2c
, lm3530_id
);
469 static struct i2c_driver lm3530_i2c_driver
= {
470 .probe
= lm3530_probe
,
471 .remove
= __devexit_p(lm3530_remove
),
472 .id_table
= lm3530_id
,
475 .owner
= THIS_MODULE
,
479 module_i2c_driver(lm3530_i2c_driver
);
481 MODULE_DESCRIPTION("Back Light driver for LM3530");
482 MODULE_LICENSE("GPL v2");
483 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");