xref: /openbmc/linux/drivers/leds/leds-da9052.c (revision 9cfc5c90)
1 /*
2  * LED Driver for Dialog DA9052 PMICs.
3  *
4  * Copyright(c) 2012 Dialog Semiconductor Ltd.
5  *
6  * Author: David Dajun Chen <dchen@diasemi.com>
7  *
8  *  This program is free software; you can redistribute  it and/or modify it
9  *  under  the terms of  the GNU General  Public License as published by the
10  *  Free Software Foundation;  either version 2 of the  License, or (at your
11  *  option) any later version.
12  *
13  */
14 
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/platform_device.h>
18 #include <linux/leds.h>
19 #include <linux/workqueue.h>
20 #include <linux/slab.h>
21 
22 #include <linux/mfd/da9052/reg.h>
23 #include <linux/mfd/da9052/da9052.h>
24 #include <linux/mfd/da9052/pdata.h>
25 
26 #define DA9052_OPENDRAIN_OUTPUT	2
27 #define DA9052_SET_HIGH_LVL_OUTPUT	(1 << 3)
28 #define DA9052_MASK_UPPER_NIBBLE	0xF0
29 #define DA9052_MASK_LOWER_NIBBLE	0x0F
30 #define DA9052_NIBBLE_SHIFT		4
31 #define DA9052_MAX_BRIGHTNESS		0x5f
32 
33 struct da9052_led {
34 	struct led_classdev cdev;
35 	struct work_struct work;
36 	struct da9052 *da9052;
37 	unsigned char led_index;
38 	unsigned char id;
39 	int brightness;
40 };
41 
42 static unsigned char led_reg[] = {
43 	DA9052_LED_CONT_4_REG,
44 	DA9052_LED_CONT_5_REG,
45 };
46 
47 static int da9052_set_led_brightness(struct da9052_led *led)
48 {
49 	u8 val;
50 	int error;
51 
52 	val = (led->brightness & 0x7f) | DA9052_LED_CONT_DIM;
53 
54 	error = da9052_reg_write(led->da9052, led_reg[led->led_index], val);
55 	if (error < 0)
56 		dev_err(led->da9052->dev, "Failed to set led brightness, %d\n",
57 			error);
58 	return error;
59 }
60 
61 static void da9052_led_work(struct work_struct *work)
62 {
63 	struct da9052_led *led = container_of(work, struct da9052_led, work);
64 
65 	da9052_set_led_brightness(led);
66 }
67 
68 static void da9052_led_set(struct led_classdev *led_cdev,
69 			   enum led_brightness value)
70 {
71 	struct da9052_led *led;
72 
73 	led = container_of(led_cdev, struct da9052_led, cdev);
74 	led->brightness = value;
75 	schedule_work(&led->work);
76 }
77 
78 static int da9052_configure_leds(struct da9052 *da9052)
79 {
80 	int error;
81 	unsigned char register_value = DA9052_OPENDRAIN_OUTPUT
82 				       | DA9052_SET_HIGH_LVL_OUTPUT;
83 
84 	error = da9052_reg_update(da9052, DA9052_GPIO_14_15_REG,
85 				  DA9052_MASK_LOWER_NIBBLE,
86 				  register_value);
87 
88 	if (error < 0) {
89 		dev_err(da9052->dev, "Failed to write GPIO 14-15 reg, %d\n",
90 			error);
91 		return error;
92 	}
93 
94 	error = da9052_reg_update(da9052, DA9052_GPIO_14_15_REG,
95 				  DA9052_MASK_UPPER_NIBBLE,
96 				  register_value << DA9052_NIBBLE_SHIFT);
97 	if (error < 0)
98 		dev_err(da9052->dev, "Failed to write GPIO 14-15 reg, %d\n",
99 			error);
100 
101 	return error;
102 }
103 
104 static int da9052_led_probe(struct platform_device *pdev)
105 {
106 	struct da9052_pdata *pdata;
107 	struct da9052 *da9052;
108 	struct led_platform_data *pled;
109 	struct da9052_led *led = NULL;
110 	int error = -ENODEV;
111 	int i;
112 
113 	da9052 = dev_get_drvdata(pdev->dev.parent);
114 	pdata = dev_get_platdata(da9052->dev);
115 	if (pdata == NULL) {
116 		dev_err(&pdev->dev, "No platform data\n");
117 		goto err;
118 	}
119 
120 	pled = pdata->pled;
121 	if (pled == NULL) {
122 		dev_err(&pdev->dev, "No platform data for LED\n");
123 		goto err;
124 	}
125 
126 	led = devm_kzalloc(&pdev->dev,
127 			   sizeof(struct da9052_led) * pled->num_leds,
128 			   GFP_KERNEL);
129 	if (!led) {
130 		error = -ENOMEM;
131 		goto err;
132 	}
133 
134 	for (i = 0; i < pled->num_leds; i++) {
135 		led[i].cdev.name = pled->leds[i].name;
136 		led[i].cdev.brightness_set = da9052_led_set;
137 		led[i].cdev.brightness = LED_OFF;
138 		led[i].cdev.max_brightness = DA9052_MAX_BRIGHTNESS;
139 		led[i].brightness = LED_OFF;
140 		led[i].led_index = pled->leds[i].flags;
141 		led[i].da9052 = dev_get_drvdata(pdev->dev.parent);
142 		INIT_WORK(&led[i].work, da9052_led_work);
143 
144 		error = led_classdev_register(pdev->dev.parent, &led[i].cdev);
145 		if (error) {
146 			dev_err(&pdev->dev, "Failed to register led %d\n",
147 				led[i].led_index);
148 			goto err_register;
149 		}
150 
151 		error = da9052_set_led_brightness(&led[i]);
152 		if (error) {
153 			dev_err(&pdev->dev, "Unable to init led %d\n",
154 				led[i].led_index);
155 			continue;
156 		}
157 	}
158 	error = da9052_configure_leds(led->da9052);
159 	if (error) {
160 		dev_err(&pdev->dev, "Failed to configure GPIO LED%d\n", error);
161 		goto err_register;
162 	}
163 
164 	platform_set_drvdata(pdev, led);
165 
166 	return 0;
167 
168 err_register:
169 	for (i = i - 1; i >= 0; i--) {
170 		led_classdev_unregister(&led[i].cdev);
171 		cancel_work_sync(&led[i].work);
172 	}
173 err:
174 	return error;
175 }
176 
177 static int da9052_led_remove(struct platform_device *pdev)
178 {
179 	struct da9052_led *led = platform_get_drvdata(pdev);
180 	struct da9052_pdata *pdata;
181 	struct da9052 *da9052;
182 	struct led_platform_data *pled;
183 	int i;
184 
185 	da9052 = dev_get_drvdata(pdev->dev.parent);
186 	pdata = dev_get_platdata(da9052->dev);
187 	pled = pdata->pled;
188 
189 	for (i = 0; i < pled->num_leds; i++) {
190 		led[i].brightness = 0;
191 		da9052_set_led_brightness(&led[i]);
192 		led_classdev_unregister(&led[i].cdev);
193 		cancel_work_sync(&led[i].work);
194 	}
195 
196 	return 0;
197 }
198 
199 static struct platform_driver da9052_led_driver = {
200 	.driver		= {
201 		.name	= "da9052-leds",
202 	},
203 	.probe		= da9052_led_probe,
204 	.remove		= da9052_led_remove,
205 };
206 
207 module_platform_driver(da9052_led_driver);
208 
209 MODULE_AUTHOR("Dialog Semiconductor Ltd <dchen@diasemi.com>");
210 MODULE_DESCRIPTION("LED driver for Dialog DA9052 PMIC");
211 MODULE_LICENSE("GPL");
212