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
26 struct lp8788_led {
27 struct lp8788 *lp;
28 struct mutex lock;
29 struct led_classdev led_dev;
30 enum lp8788_isink_number isink_num;
31 int on;
32 };
33
34 struct lp8788_led_config {
35 enum lp8788_isink_scale scale;
36 enum lp8788_isink_number num;
37 int iout;
38 };
39
40 static struct lp8788_led_config default_led_config = {
41 .scale = LP8788_ISINK_SCALE_100mA,
42 .num = LP8788_ISINK_3,
43 .iout = 0,
44 };
45
lp8788_led_init_device(struct lp8788_led * led,struct lp8788_led_platform_data * pdata)46 static int lp8788_led_init_device(struct lp8788_led *led,
47 struct lp8788_led_platform_data *pdata)
48 {
49 struct lp8788_led_config *cfg = &default_led_config;
50 u8 addr, mask, val;
51 int ret;
52
53 if (pdata) {
54 cfg->scale = pdata->scale;
55 cfg->num = pdata->num;
56 cfg->iout = pdata->iout_code;
57 }
58
59 led->isink_num = cfg->num;
60
61 /* scale configuration */
62 addr = LP8788_ISINK_CTRL;
63 mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
64 val = cfg->scale << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
65 ret = lp8788_update_bits(led->lp, addr, mask, val);
66 if (ret)
67 return ret;
68
69 /* current configuration */
70 addr = lp8788_iout_addr[cfg->num];
71 mask = lp8788_iout_mask[cfg->num];
72 val = cfg->iout;
73
74 return lp8788_update_bits(led->lp, addr, mask, val);
75 }
76
lp8788_led_enable(struct lp8788_led * led,enum lp8788_isink_number num,int on)77 static int lp8788_led_enable(struct lp8788_led *led,
78 enum lp8788_isink_number num, int on)
79 {
80 int ret;
81
82 u8 mask = 1 << num;
83 u8 val = on << num;
84
85 ret = lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val);
86 if (ret == 0)
87 led->on = on;
88
89 return ret;
90 }
91
lp8788_brightness_set(struct led_classdev * led_cdev,enum led_brightness val)92 static int lp8788_brightness_set(struct led_classdev *led_cdev,
93 enum led_brightness val)
94 {
95 struct lp8788_led *led =
96 container_of(led_cdev, struct lp8788_led, led_dev);
97
98 enum lp8788_isink_number num = led->isink_num;
99 int enable, ret;
100
101 mutex_lock(&led->lock);
102
103 switch (num) {
104 case LP8788_ISINK_1:
105 case LP8788_ISINK_2:
106 case LP8788_ISINK_3:
107 ret = lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val);
108 if (ret < 0)
109 goto unlock;
110 break;
111 default:
112 mutex_unlock(&led->lock);
113 return -EINVAL;
114 }
115
116 enable = (val > 0) ? 1 : 0;
117 if (enable != led->on)
118 ret = lp8788_led_enable(led, num, enable);
119 unlock:
120 mutex_unlock(&led->lock);
121 return ret;
122 }
123
lp8788_led_probe(struct platform_device * pdev)124 static int lp8788_led_probe(struct platform_device *pdev)
125 {
126 struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
127 struct lp8788_led_platform_data *led_pdata;
128 struct lp8788_led *led;
129 struct device *dev = &pdev->dev;
130 int ret;
131
132 led = devm_kzalloc(dev, sizeof(struct lp8788_led), GFP_KERNEL);
133 if (!led)
134 return -ENOMEM;
135
136 led->lp = lp;
137 led->led_dev.max_brightness = MAX_BRIGHTNESS;
138 led->led_dev.brightness_set_blocking = lp8788_brightness_set;
139
140 led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
141
142 if (!led_pdata || !led_pdata->name)
143 led->led_dev.name = DEFAULT_LED_NAME;
144 else
145 led->led_dev.name = led_pdata->name;
146
147 mutex_init(&led->lock);
148
149 ret = lp8788_led_init_device(led, led_pdata);
150 if (ret) {
151 dev_err(dev, "led init device err: %d\n", ret);
152 return ret;
153 }
154
155 ret = devm_led_classdev_register(dev, &led->led_dev);
156 if (ret) {
157 dev_err(dev, "led register err: %d\n", ret);
158 return ret;
159 }
160
161 return 0;
162 }
163
164 static struct platform_driver lp8788_led_driver = {
165 .probe = lp8788_led_probe,
166 .driver = {
167 .name = LP8788_DEV_KEYLED,
168 },
169 };
170 module_platform_driver(lp8788_led_driver);
171
172 MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
173 MODULE_AUTHOR("Milo Kim");
174 MODULE_LICENSE("GPL");
175 MODULE_ALIAS("platform:lp8788-keyled");
176
