aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/leds/leds-pca9633.c
blob: 2f2f9c43535dcb1c3940178c6b56e4f6280ba831 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/*
 * Copyright 2011 bct electronic GmbH
 *
 * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
 *
 * Based on leds-pca955x.c
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
 *
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/platform_data/leds-pca9633.h>

/* LED select registers determine the source that drives LED outputs */
#define PCA9633_LED_OFF		0x0	/* LED driver off */
#define PCA9633_LED_ON		0x1	/* LED driver on */
#define PCA9633_LED_PWM		0x2	/* Controlled through PWM */
#define PCA9633_LED_GRP_PWM	0x3	/* Controlled through PWM/GRPPWM */

#define PCA9633_MODE1		0x00
#define PCA9633_MODE2		0x01
#define PCA9633_PWM_BASE	0x02
#define PCA9633_LEDOUT		0x08

static const struct i2c_device_id pca9633_id[] = {
	{ "pca9633", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pca9633_id);

struct pca9633_led {
	struct i2c_client *client;
	struct work_struct work;
	enum led_brightness brightness;
	struct led_classdev led_cdev;
	int led_num; /* 0 .. 3 potentially */
	char name[32];
};

static void pca9633_led_work(struct work_struct *work)
{
	struct pca9633_led *pca9633 = container_of(work,
		struct pca9633_led, work);
	u8 ledout = i2c_smbus_read_byte_data(pca9633->client, PCA9633_LEDOUT);
	int shift = 2 * pca9633->led_num;
	u8 mask = 0x3 << shift;

	switch (pca9633->brightness) {
	case LED_FULL:
		i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
			(ledout & ~mask) | (PCA9633_LED_ON << shift));
		break;
	case LED_OFF:
		i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
			ledout & ~mask);
		break;
	default:
		i2c_smbus_write_byte_data(pca9633->client,
			PCA9633_PWM_BASE + pca9633->led_num,
			pca9633->brightness);
		i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
			(ledout & ~mask) | (PCA9633_LED_PWM << shift));
		break;
	}
}

static void pca9633_led_set(struct led_classdev *led_cdev,
	enum led_brightness value)
{
	struct pca9633_led *pca9633;

	pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev);

	pca9633->brightness = value;

	/*
	 * Must use workqueue for the actual I/O since I2C operations
	 * can sleep.
	 */
	schedule_work(&pca9633->work);
}

static int __devinit pca9633_probe(struct i2c_client *client,
					const struct i2c_device_id *id)
{
	struct pca9633_led *pca9633;
	struct pca9633_platform_data *pdata;
	int i, err;

	pdata = client->dev.platform_data;

	if (pdata) {
		if (pdata->leds.num_leds <= 0 || pdata->leds.num_leds > 4) {
			dev_err(&client->dev, "board info must claim at most 4 LEDs");
			return -EINVAL;
		}
	}

	pca9633 = devm_kzalloc(&client->dev, 4 * sizeof(*pca9633), GFP_KERNEL);
	if (!pca9633)
		return -ENOMEM;

	i2c_set_clientdata(client, pca9633);

	for (i = 0; i < 4; i++) {
		pca9633[i].client = client;
		pca9633[i].led_num = i;

		/* Platform data can specify LED names and default triggers */
		if (pdata && i < pdata->leds.num_leds) {
			if (pdata->leds.leds[i].name)
				snprintf(pca9633[i].name,
					 sizeof(pca9633[i].name), "pca9633:%s",
					 pdata->leds.leds[i].name);
			if (pdata->leds.leds[i].default_trigger)
				pca9633[i].led_cdev.default_trigger =
					pdata->leds.leds[i].default_trigger;
		} else {
			snprintf(pca9633[i].name, sizeof(pca9633[i].name),
				 "pca9633:%d", i);
		}

		pca9633[i].led_cdev.name = pca9633[i].name;
		pca9633[i].led_cdev.brightness_set = pca9633_led_set;

		INIT_WORK(&pca9633[i].work, pca9633_led_work);

		err = led_classdev_register(&client->dev, &pca9633[i].led_cdev);
		if (err < 0)
			goto exit;
	}

	/* Disable LED all-call address and set normal mode */
	i2c_smbus_write_byte_data(client, PCA9633_MODE1, 0x00);

	/* Configure output: open-drain or totem pole (push-pull) */
	if (pdata && pdata->outdrv == PCA9633_OPEN_DRAIN)
		i2c_smbus_write_byte_data(client, PCA9633_MODE2, 0x01);

	/* Turn off LEDs */
	i2c_smbus_write_byte_data(client, PCA9633_LEDOUT, 0x00);

	return 0;

exit:
	while (i--) {
		led_classdev_unregister(&pca9633[i].led_cdev);
		cancel_work_sync(&pca9633[i].work);
	}

	return err;
}

static int __devexit pca9633_remove(struct i2c_client *client)
{
	struct pca9633_led *pca9633 = i2c_get_clientdata(client);
	int i;

	for (i = 0; i < 4; i++) {
		led_classdev_unregister(&pca9633[i].led_cdev);
		cancel_work_sync(&pca9633[i].work);
	}

	return 0;
}

static struct i2c_driver pca9633_driver = {
	.driver = {
		.name	= "leds-pca9633",
		.owner	= THIS_MODULE,
	},
	.probe	= pca9633_probe,
	.remove	= __devexit_p(pca9633_remove),
	.id_table = pca9633_id,
};

module_i2c_driver(pca9633_driver);

MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
MODULE_DESCRIPTION("PCA9633 LED driver");
MODULE_LICENSE("GPL v2");