Blame view

kernel/linux-imx6_3.14.28/drivers/mfd/lp3943.c 4.32 KB
6b13f685e   김민수   BSP 최초 추가
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
  /*
   * TI/National Semiconductor LP3943 MFD Core Driver
   *
   * Copyright 2013 Texas Instruments
   *
   * Author: Milo 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.
   *
   * Driver structure:
   *   LP3943 is an integrated device capable of driving 16 output channels.
   *   It can be used for a GPIO expander and PWM generators.
   *
   *                                   LED control    General usage for a device
   *                                   ___________   ____________________________
   *
   *   LP3943 MFD ---- GPIO expander    leds-gpio        eg) HW enable pin
   *               |
   *               --- PWM generator    leds-pwm         eg) PWM input
   *
   *   Internal two PWM channels are used for LED dimming effect.
   *   And each output pin can be used as a GPIO as well.
   *   The LED functionality can work with GPIOs or PWMs.
   *   LEDs can be controlled with legacy leds-gpio(static brightness) or
   *   leds-pwm drivers(dynamic brightness control).
   *   Alternatively, it can be used for generic GPIO and PWM controller.
   *   For example, a GPIO is HW enable pin of a device.
   *   A PWM is input pin of a backlight device.
   */
  
  #include <linux/err.h>
  #include <linux/gpio.h>
  #include <linux/i2c.h>
  #include <linux/mfd/core.h>
  #include <linux/mfd/lp3943.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/slab.h>
  
  #define LP3943_MAX_REGISTERS		0x09
  
  /* Register configuration for pin MUX */
  static const struct lp3943_reg_cfg lp3943_mux_cfg[] = {
  	/* address, mask, shift */
  	{ LP3943_REG_MUX0, 0x03, 0 },
  	{ LP3943_REG_MUX0, 0x0C, 2 },
  	{ LP3943_REG_MUX0, 0x30, 4 },
  	{ LP3943_REG_MUX0, 0xC0, 6 },
  	{ LP3943_REG_MUX1, 0x03, 0 },
  	{ LP3943_REG_MUX1, 0x0C, 2 },
  	{ LP3943_REG_MUX1, 0x30, 4 },
  	{ LP3943_REG_MUX1, 0xC0, 6 },
  	{ LP3943_REG_MUX2, 0x03, 0 },
  	{ LP3943_REG_MUX2, 0x0C, 2 },
  	{ LP3943_REG_MUX2, 0x30, 4 },
  	{ LP3943_REG_MUX2, 0xC0, 6 },
  	{ LP3943_REG_MUX3, 0x03, 0 },
  	{ LP3943_REG_MUX3, 0x0C, 2 },
  	{ LP3943_REG_MUX3, 0x30, 4 },
  	{ LP3943_REG_MUX3, 0xC0, 6 },
  };
  
  static struct mfd_cell lp3943_devs[] = {
  	{
  		.name = "lp3943-pwm",
  		.of_compatible = "ti,lp3943-pwm",
  	},
  	{
  		.name = "lp3943-gpio",
  		.of_compatible = "ti,lp3943-gpio",
  	},
  };
  
  int lp3943_read_byte(struct lp3943 *lp3943, u8 reg, u8 *read)
  {
  	int ret;
  	unsigned int val;
  
  	ret = regmap_read(lp3943->regmap, reg, &val);
  	if (ret < 0)
  		return ret;
  
  	*read = (u8)val;
  	return 0;
  }
  EXPORT_SYMBOL_GPL(lp3943_read_byte);
  
  int lp3943_write_byte(struct lp3943 *lp3943, u8 reg, u8 data)
  {
  	return regmap_write(lp3943->regmap, reg, data);
  }
  EXPORT_SYMBOL_GPL(lp3943_write_byte);
  
  int lp3943_update_bits(struct lp3943 *lp3943, u8 reg, u8 mask, u8 data)
  {
  	return regmap_update_bits(lp3943->regmap, reg, mask, data);
  }
  EXPORT_SYMBOL_GPL(lp3943_update_bits);
  
  static const struct regmap_config lp3943_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 8,
  	.max_register = LP3943_MAX_REGISTERS,
  };
  
  static int lp3943_probe(struct i2c_client *cl, const struct i2c_device_id *id)
  {
  	struct lp3943 *lp3943;
  	struct device *dev = &cl->dev;
  
  	lp3943 = devm_kzalloc(dev, sizeof(*lp3943), GFP_KERNEL);
  	if (!lp3943)
  		return -ENOMEM;
  
  	lp3943->regmap = devm_regmap_init_i2c(cl, &lp3943_regmap_config);
  	if (IS_ERR(lp3943->regmap))
  		return PTR_ERR(lp3943->regmap);
  
  	lp3943->pdata = dev_get_platdata(dev);
  	lp3943->dev = dev;
  	lp3943->mux_cfg = lp3943_mux_cfg;
  	i2c_set_clientdata(cl, lp3943);
  
  	return mfd_add_devices(dev, -1, lp3943_devs, ARRAY_SIZE(lp3943_devs),
  			       NULL, 0, NULL);
  }
  
  static int lp3943_remove(struct i2c_client *cl)
  {
  	struct lp3943 *lp3943 = i2c_get_clientdata(cl);
  
  	mfd_remove_devices(lp3943->dev);
  	return 0;
  }
  
  static const struct i2c_device_id lp3943_ids[] = {
  	{ "lp3943", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, lp3943_ids);
  
  #ifdef CONFIG_OF
  static const struct of_device_id lp3943_of_match[] = {
  	{ .compatible = "ti,lp3943", },
  	{ }
  };
  MODULE_DEVICE_TABLE(of, lp3943_of_match);
  #endif
  
  static struct i2c_driver lp3943_driver = {
  	.probe = lp3943_probe,
  	.remove = lp3943_remove,
  	.driver = {
  		.name = "lp3943",
  		.owner = THIS_MODULE,
  		.of_match_table = of_match_ptr(lp3943_of_match),
  	},
  	.id_table = lp3943_ids,
  };
  
  module_i2c_driver(lp3943_driver);
  
  MODULE_DESCRIPTION("LP3943 MFD Core Driver");
  MODULE_AUTHOR("Milo Kim");
  MODULE_LICENSE("GPL");