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	},
187};
188module_platform_driver(lp8788_led_driver);
189
190MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
191MODULE_AUTHOR("Milo Kim");
192MODULE_LICENSE("GPL");
193MODULE_ALIAS("platform:lp8788-keyled");
194