summaryrefslogtreecommitdiffstats
path: root/drivers/leds/leds-lp55xx-common.c
blob: 74beb363b7873bdc2670693acf615d5ef5a456ea (plain)
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
/*
 * LP5521/LP5523/LP55231 Common Driver
 *
 * Copyright 2012 Texas Instruments
 *
 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Derived from leds-lp5521.c, leds-lp5523.c
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/platform_data/leds-lp55xx.h>

#include "leds-lp55xx-common.h"

static void lp55xx_reset_device(struct lp55xx_chip *chip)
{
	struct lp55xx_device_config *cfg = chip->cfg;
	u8 addr = cfg->reset.addr;
	u8 val  = cfg->reset.val;

	/* no error checking here because no ACK from the device after reset */
	lp55xx_write(chip, addr, val);
}

static int lp55xx_detect_device(struct lp55xx_chip *chip)
{
	struct lp55xx_device_config *cfg = chip->cfg;
	u8 addr = cfg->enable.addr;
	u8 val  = cfg->enable.val;
	int ret;

	ret = lp55xx_write(chip, addr, val);
	if (ret)
		return ret;

	usleep_range(1000, 2000);

	ret = lp55xx_read(chip, addr, &val);
	if (ret)
		return ret;

	if (val != cfg->enable.val)
		return -ENODEV;

	return 0;
}

static int lp55xx_post_init_device(struct lp55xx_chip *chip)
{
	struct lp55xx_device_config *cfg = chip->cfg;

	if (!cfg->post_init_device)
		return 0;

	return cfg->post_init_device(chip);
}

int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
{
	return i2c_smbus_write_byte_data(chip->cl, reg, val);
}
EXPORT_SYMBOL_GPL(lp55xx_write);

int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
{
	s32 ret;

	ret = i2c_smbus_read_byte_data(chip->cl, reg);
	if (ret < 0)
		return ret;

	*val = ret;
	return 0;
}
EXPORT_SYMBOL_GPL(lp55xx_read);

int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
{
	int ret;
	u8 tmp;

	ret = lp55xx_read(chip, reg, &tmp);
	if (ret)
		return ret;

	tmp &= ~mask;
	tmp |= val & mask;

	return lp55xx_write(chip, reg, tmp);
}
EXPORT_SYMBOL_GPL(lp55xx_update_bits);

int lp55xx_init_device(struct lp55xx_chip *chip)
{
	struct lp55xx_platform_data *pdata;
	struct lp55xx_device_config *cfg;
	struct device *dev = &chip->cl->dev;
	int ret = 0;

	WARN_ON(!chip);

	pdata = chip->pdata;
	cfg = chip->cfg;

	if (!pdata || !cfg)
		return -EINVAL;

	if (pdata->setup_resources) {
		ret = pdata->setup_resources();
		if (ret < 0) {
			dev_err(dev, "setup resoure err: %d\n", ret);
			goto err;
		}
	}

	if (pdata->enable) {
		pdata->enable(0);
		usleep_range(1000, 2000); /* Keep enable down at least 1ms */
		pdata->enable(1);
		usleep_range(1000, 2000); /* 500us abs min. */
	}

	lp55xx_reset_device(chip);

	/*
	 * Exact value is not available. 10 - 20ms
	 * appears to be enough for reset.
	 */
	usleep_range(10000, 20000);

	ret = lp55xx_detect_device(chip);
	if (ret) {
		dev_err(dev, "device detection err: %d\n", ret);
		goto err;
	}

	/* chip specific initialization */
	ret = lp55xx_post_init_device(chip);

	return 0;

err:
	return ret;
}
EXPORT_SYMBOL_GPL(lp55xx_init_device);

MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
MODULE_DESCRIPTION("LP55xx Common Driver");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud