1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * TI LP8788 MFD - keyled driver
4 *
5 * Copyright 2012 Texas Instruments
6 *
7 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
8 */
9
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/err.h>
13#include <linux/platform_device.h>
14#include <linux/leds.h>
15#include <linux/mutex.h>
16#include <linux/mfd/lp8788.h>
17#include <linux/mfd/lp8788-isink.h>
18
19#define MAX_BRIGHTNESS			LP8788_ISINK_MAX_PWM
20#define DEFAULT_LED_NAME		"keyboard-backlight"
21
22struct lp8788_led {
23	struct lp8788 *lp;
24	struct mutex lock;
25	struct led_classdev led_dev;
26	enum lp8788_isink_number isink_num;
27	int on;
28};
29
30struct lp8788_led_config {
31	enum lp8788_isink_scale scale;
32	enum lp8788_isink_number num;
33	int iout;
34};
35
36static struct lp8788_led_config default_led_config = {
37	.scale = LP8788_ISINK_SCALE_100mA,
38	.num   = LP8788_ISINK_3,
39	.iout  = 0,
40};
41
42static int lp8788_led_init_device(struct lp8788_led *led,
43				struct lp8788_led_platform_data *pdata)
44{
45	struct lp8788_led_config *cfg = &default_led_config;
46	u8 addr, mask, val;
47	int ret;
48
49	if (pdata) {
50		cfg->scale = pdata->scale;
51		cfg->num = pdata->num;
52		cfg->iout = pdata->iout_code;
53	}
54
55	led->isink_num = cfg->num;
56
57	/* scale configuration */
58	addr = LP8788_ISINK_CTRL;
59	mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
60	val = cfg->scale << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
61	ret = lp8788_update_bits(led->lp, addr, mask, val);
62	if (ret)
63		return ret;
64
65	/* current configuration */
66	addr = lp8788_iout_addr[cfg->num];
67	mask = lp8788_iout_mask[cfg->num];
68	val = cfg->iout;
69
70	return lp8788_update_bits(led->lp, addr, mask, val);
71}
72
73static int lp8788_led_enable(struct lp8788_led *led,
74			enum lp8788_isink_number num, int on)
75{
76	int ret;
77
78	u8 mask = 1 << num;
79	u8 val = on << num;
80
81	ret = lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val);
82	if (ret == 0)
83		led->on = on;
84
85	return ret;
86}
87
88static int lp8788_brightness_set(struct led_classdev *led_cdev,
89				enum led_brightness val)
90{
91	struct lp8788_led *led =
92			container_of(led_cdev, struct lp8788_led, led_dev);
93
94	enum lp8788_isink_number num = led->isink_num;
95	int enable, ret;
96
97	mutex_lock(&led->lock);
98
99	switch (num) {
100	case LP8788_ISINK_1:
101	case LP8788_ISINK_2:
102	case LP8788_ISINK_3:
103		ret = lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val);
104		if (ret < 0)
105			goto unlock;
106		break;
107	default:
108		mutex_unlock(&led->lock);
109		return -EINVAL;
110	}
111
112	enable = (val > 0) ? 1 : 0;
113	if (enable != led->on)
114		ret = lp8788_led_enable(led, num, enable);
115unlock:
116	mutex_unlock(&led->lock);
117	return ret;
118}
119
120static int lp8788_led_probe(struct platform_device *pdev)
121{
122	struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
123	struct lp8788_led_platform_data *led_pdata;
124	struct lp8788_led *led;
125	struct device *dev = &pdev->dev;
126	int ret;
127
128	led = devm_kzalloc(dev, sizeof(struct lp8788_led), GFP_KERNEL);
129	if (!led)
130		return -ENOMEM;
131
132	led->lp = lp;
133	led->led_dev.max_brightness = MAX_BRIGHTNESS;
134	led->led_dev.brightness_set_blocking = lp8788_brightness_set;
135
136	led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
137
138	if (!led_pdata || !led_pdata->name)
139		led->led_dev.name = DEFAULT_LED_NAME;
140	else
141		led->led_dev.name = led_pdata->name;
142
143	mutex_init(&led->lock);
144
145	ret = lp8788_led_init_device(led, led_pdata);
146	if (ret) {
147		dev_err(dev, "led init device err: %d\n", ret);
148		return ret;
149	}
150
151	ret = devm_led_classdev_register(dev, &led->led_dev);
152	if (ret) {
153		dev_err(dev, "led register err: %d\n", ret);
154		return ret;
155	}
156
157	return 0;
158}
159
160static struct platform_driver lp8788_led_driver = {
161	.probe = lp8788_led_probe,
162	.driver = {
163		.name = LP8788_DEV_KEYLED,
164	},
165};
166module_platform_driver(lp8788_led_driver);
167
168MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
169MODULE_AUTHOR("Milo Kim");
170MODULE_LICENSE("GPL");
171MODULE_ALIAS("platform:lp8788-keyled");
172