Root/drivers/leds/leds-lp8788.c

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 + LP8788_ISINK_SCALE_OFFSET);
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        mutex_unlock(&led->lock);
108        return;
109    }
110
111    enable = (val > 0) ? 1 : 0;
112    if (enable != led->on)
113        lp8788_led_enable(led, num, enable);
114
115    mutex_unlock(&led->lock);
116}
117
118static void lp8788_brightness_set(struct led_classdev *led_cdev,
119                enum led_brightness brt_val)
120{
121    struct lp8788_led *led =
122            container_of(led_cdev, struct lp8788_led, led_dev);
123
124    led->brightness = brt_val;
125    schedule_work(&led->work);
126}
127
128static int lp8788_led_probe(struct platform_device *pdev)
129{
130    struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
131    struct lp8788_led_platform_data *led_pdata;
132    struct lp8788_led *led;
133    struct device *dev = &pdev->dev;
134    int ret;
135
136    led = devm_kzalloc(dev, sizeof(struct lp8788_led), GFP_KERNEL);
137    if (!led)
138        return -ENOMEM;
139
140    led->lp = lp;
141    led->led_dev.max_brightness = MAX_BRIGHTNESS;
142    led->led_dev.brightness_set = lp8788_brightness_set;
143
144    led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
145
146    if (!led_pdata || !led_pdata->name)
147        led->led_dev.name = DEFAULT_LED_NAME;
148    else
149        led->led_dev.name = led_pdata->name;
150
151    mutex_init(&led->lock);
152    INIT_WORK(&led->work, lp8788_led_work);
153
154    platform_set_drvdata(pdev, led);
155
156    ret = lp8788_led_init_device(led, led_pdata);
157    if (ret) {
158        dev_err(dev, "led init device err: %d\n", ret);
159        return ret;
160    }
161
162    ret = led_classdev_register(dev, &led->led_dev);
163    if (ret) {
164        dev_err(dev, "led register err: %d\n", ret);
165        return ret;
166    }
167
168    return 0;
169}
170
171static int lp8788_led_remove(struct platform_device *pdev)
172{
173    struct lp8788_led *led = platform_get_drvdata(pdev);
174
175    led_classdev_unregister(&led->led_dev);
176    flush_work(&led->work);
177
178    return 0;
179}
180
181static struct platform_driver lp8788_led_driver = {
182    .probe = lp8788_led_probe,
183    .remove = lp8788_led_remove,
184    .driver = {
185        .name = LP8788_DEV_KEYLED,
186        .owner = THIS_MODULE,
187    },
188};
189module_platform_driver(lp8788_led_driver);
190
191MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
192MODULE_AUTHOR("Milo Kim");
193MODULE_LICENSE("GPL");
194MODULE_ALIAS("platform:lp8788-keyled");
195

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