xref: /openbmc/linux/drivers/leds/leds-lp8788.c (revision d2912cb1)
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 
22 struct 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 
30 struct lp8788_led_config {
31 	enum lp8788_isink_scale scale;
32 	enum lp8788_isink_number num;
33 	int iout;
34 };
35 
36 static struct lp8788_led_config default_led_config = {
37 	.scale = LP8788_ISINK_SCALE_100mA,
38 	.num   = LP8788_ISINK_3,
39 	.iout  = 0,
40 };
41 
lp8788_led_init_device(struct lp8788_led * led,struct lp8788_led_platform_data * pdata)42 static 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 
lp8788_led_enable(struct lp8788_led * led,enum lp8788_isink_number num,int on)73 static 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 
lp8788_brightness_set(struct led_classdev * led_cdev,enum led_brightness val)88 static 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);
115 unlock:
116 	mutex_unlock(&led->lock);
117 	return ret;
118 }
119 
lp8788_led_probe(struct platform_device * pdev)120 static 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 
160 static struct platform_driver lp8788_led_driver = {
161 	.probe = lp8788_led_probe,
162 	.driver = {
163 		.name = LP8788_DEV_KEYLED,
164 	},
165 };
166 module_platform_driver(lp8788_led_driver);
167 
168 MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
169 MODULE_AUTHOR("Milo Kim");
170 MODULE_LICENSE("GPL");
171 MODULE_ALIAS("platform:lp8788-keyled");
172