leds: add new lp8788 led driver
[deliverable/linux.git] / drivers / leds / leds-lp8788.c
CommitLineData
eb80411b
KM
1/*
2 * TI LP8788 MFD - keyled driver
3 *
4 * Copyright 2012 Texas Instruments
5 *
6 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17#include <linux/platform_device.h>
18#include <linux/leds.h>
19#include <linux/mutex.h>
20#include <linux/mfd/lp8788.h>
21#include <linux/mfd/lp8788-isink.h>
22
23#define MAX_BRIGHTNESS LP8788_ISINK_MAX_PWM
24#define DEFAULT_LED_NAME "keyboard-backlight"
25
26struct lp8788_led {
27 struct lp8788 *lp;
28 struct mutex lock;
29 struct work_struct work;
30 struct led_classdev led_dev;
31 enum lp8788_isink_number isink_num;
32 enum led_brightness brightness;
33 int on;
34};
35
36struct lp8788_led_config {
37 enum lp8788_isink_scale scale;
38 enum lp8788_isink_number num;
39 int iout;
40};
41
42static struct lp8788_led_config default_led_config = {
43 .scale = LP8788_ISINK_SCALE_100mA,
44 .num = LP8788_ISINK_3,
45 .iout = 0,
46};
47
48static int lp8788_led_init_device(struct lp8788_led *led,
49 struct lp8788_led_platform_data *pdata)
50{
51 struct lp8788_led_config *cfg = &default_led_config;
52 u8 addr, mask, val;
53 int ret;
54
55 if (pdata) {
56 cfg->scale = pdata->scale;
57 cfg->num = pdata->num;
58 cfg->iout = pdata->iout_code;
59 }
60
61 led->isink_num = cfg->num;
62
63 /* scale configuration */
64 addr = LP8788_ISINK_CTRL;
65 mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
66 val = cfg->scale << cfg->num;
67 ret = lp8788_update_bits(led->lp, addr, mask, val);
68 if (ret)
69 return ret;
70
71 /* current configuration */
72 addr = lp8788_iout_addr[cfg->num];
73 mask = lp8788_iout_mask[cfg->num];
74 val = cfg->iout;
75
76 return lp8788_update_bits(led->lp, addr, mask, val);
77}
78
79static void lp8788_led_enable(struct lp8788_led *led,
80 enum lp8788_isink_number num, int on)
81{
82 u8 mask = 1 << num;
83 u8 val = on << num;
84
85 if (lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val))
86 return;
87
88 led->on = on;
89}
90
91static void lp8788_led_work(struct work_struct *work)
92{
93 struct lp8788_led *led = container_of(work, struct lp8788_led, work);
94 enum lp8788_isink_number num = led->isink_num;
95 int enable;
96 u8 val = led->brightness;
97
98 mutex_lock(&led->lock);
99
100 switch (num) {
101 case LP8788_ISINK_1:
102 case LP8788_ISINK_2:
103 case LP8788_ISINK_3:
104 lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val);
105 break;
106 default:
107 return;
108 }
109
110 enable = (val > 0) ? 1 : 0;
111 if (enable != led->on)
112 lp8788_led_enable(led, num, enable);
113
114 mutex_unlock(&led->lock);
115}
116
117static void lp8788_brightness_set(struct led_classdev *led_cdev,
118 enum led_brightness brt_val)
119{
120 struct lp8788_led *led =
121 container_of(led_cdev, struct lp8788_led, led_dev);
122
123 led->brightness = brt_val;
124 schedule_work(&led->work);
125}
126
127static __devinit int lp8788_led_probe(struct platform_device *pdev)
128{
129 struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
130 struct lp8788_led_platform_data *led_pdata;
131 struct lp8788_led *led;
132 int ret;
133
134 led = devm_kzalloc(lp->dev, sizeof(struct lp8788_led), GFP_KERNEL);
135 if (!led)
136 return -ENOMEM;
137
138 led->lp = lp;
139 led->led_dev.max_brightness = MAX_BRIGHTNESS;
140 led->led_dev.brightness_set = lp8788_brightness_set;
141
142 led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
143
144 if (!led_pdata || !led_pdata->name)
145 led->led_dev.name = DEFAULT_LED_NAME;
146 else
147 led->led_dev.name = led_pdata->name;
148
149 mutex_init(&led->lock);
150 INIT_WORK(&led->work, lp8788_led_work);
151
152 platform_set_drvdata(pdev, led);
153
154 ret = lp8788_led_init_device(led, led_pdata);
155 if (ret) {
156 dev_err(lp->dev, "led init device err: %d\n", ret);
157 return ret;
158 }
159
160 ret = led_classdev_register(lp->dev, &led->led_dev);
161 if (ret) {
162 dev_err(lp->dev, "led register err: %d\n", ret);
163 return ret;
164 }
165
166 return 0;
167}
168
169static int __devexit lp8788_led_remove(struct platform_device *pdev)
170{
171 struct lp8788_led *led = platform_get_drvdata(pdev);
172
173 led_classdev_unregister(&led->led_dev);
174 flush_work_sync(&led->work);
175
176 return 0;
177}
178
179static struct platform_driver lp8788_led_driver = {
180 .probe = lp8788_led_probe,
181 .remove = __devexit_p(lp8788_led_remove),
182 .driver = {
183 .name = LP8788_DEV_KEYLED,
184 .owner = THIS_MODULE,
185 },
186};
187module_platform_driver(lp8788_led_driver);
188
189MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
190MODULE_AUTHOR("Milo Kim");
191MODULE_LICENSE("GPL");
192MODULE_ALIAS("platform:lp8788-keyled");
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