1/*
2 * TI/National Semiconductor LP3943 MFD Core Driver
3 *
4 * Copyright 2013 Texas Instruments
5 *
6 * Author: Milo Kim <milo.kim@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * Driver structure:
13 * LP3943 is an integrated device capable of driving 16 output channels.
14 * It can be used for a GPIO expander and PWM generators.
15 *
16 * LED control General usage for a device
17 * ___________ ____________________________
18 *
19 * LP3943 MFD ---- GPIO expander leds-gpio eg) HW enable pin
20 * |
21 * --- PWM generator leds-pwm eg) PWM input
22 *
23 * Internal two PWM channels are used for LED dimming effect.
24 * And each output pin can be used as a GPIO as well.
25 * The LED functionality can work with GPIOs or PWMs.
26 * LEDs can be controlled with legacy leds-gpio(static brightness) or
27 * leds-pwm drivers(dynamic brightness control).
28 * Alternatively, it can be used for generic GPIO and PWM controller.
29 * For example, a GPIO is HW enable pin of a device.
30 * A PWM is input pin of a backlight device.
31 */
32
33#include <linux/err.h>
34#include <linux/gpio.h>
35#include <linux/i2c.h>
36#include <linux/mfd/core.h>
37#include <linux/mfd/lp3943.h>
38#include <linux/module.h>
39#include <linux/of.h>
40#include <linux/slab.h>
41
42#define LP3943_MAX_REGISTERS 0x09
43
44/* Register configuration for pin MUX */
45static const struct lp3943_reg_cfg lp3943_mux_cfg[] = {
46 /* address, mask, shift */
47 { LP3943_REG_MUX0, 0x03, 0 },
48 { LP3943_REG_MUX0, 0x0C, 2 },
49 { LP3943_REG_MUX0, 0x30, 4 },
50 { LP3943_REG_MUX0, 0xC0, 6 },
51 { LP3943_REG_MUX1, 0x03, 0 },
52 { LP3943_REG_MUX1, 0x0C, 2 },
53 { LP3943_REG_MUX1, 0x30, 4 },
54 { LP3943_REG_MUX1, 0xC0, 6 },
55 { LP3943_REG_MUX2, 0x03, 0 },
56 { LP3943_REG_MUX2, 0x0C, 2 },
57 { LP3943_REG_MUX2, 0x30, 4 },
58 { LP3943_REG_MUX2, 0xC0, 6 },
59 { LP3943_REG_MUX3, 0x03, 0 },
60 { LP3943_REG_MUX3, 0x0C, 2 },
61 { LP3943_REG_MUX3, 0x30, 4 },
62 { LP3943_REG_MUX3, 0xC0, 6 },
63};
64
65static const struct mfd_cell lp3943_devs[] = {
66 {
67 .name = "lp3943-pwm",
68 .of_compatible = "ti,lp3943-pwm",
69 },
70 {
71 .name = "lp3943-gpio",
72 .of_compatible = "ti,lp3943-gpio",
73 },
74};
75
76int lp3943_read_byte(struct lp3943 *lp3943, u8 reg, u8 *read)
77{
78 int ret;
79 unsigned int val;
80
81 ret = regmap_read(lp3943->regmap, reg, &val);
82 if (ret < 0)
83 return ret;
84
85 *read = (u8)val;
86 return 0;
87}
88EXPORT_SYMBOL_GPL(lp3943_read_byte);
89
90int lp3943_write_byte(struct lp3943 *lp3943, u8 reg, u8 data)
91{
92 return regmap_write(lp3943->regmap, reg, data);
93}
94EXPORT_SYMBOL_GPL(lp3943_write_byte);
95
96int lp3943_update_bits(struct lp3943 *lp3943, u8 reg, u8 mask, u8 data)
97{
98 return regmap_update_bits(lp3943->regmap, reg, mask, data);
99}
100EXPORT_SYMBOL_GPL(lp3943_update_bits);
101
102static const struct regmap_config lp3943_regmap_config = {
103 .reg_bits = 8,
104 .val_bits = 8,
105 .max_register = LP3943_MAX_REGISTERS,
106};
107
108static int lp3943_probe(struct i2c_client *cl, const struct i2c_device_id *id)
109{
110 struct lp3943 *lp3943;
111 struct device *dev = &cl->dev;
112
113 lp3943 = devm_kzalloc(dev, sizeof(*lp3943), GFP_KERNEL);
114 if (!lp3943)
115 return -ENOMEM;
116
117 lp3943->regmap = devm_regmap_init_i2c(cl, &lp3943_regmap_config);
118 if (IS_ERR(lp3943->regmap))
119 return PTR_ERR(lp3943->regmap);
120
121 lp3943->pdata = dev_get_platdata(dev);
122 lp3943->dev = dev;
123 lp3943->mux_cfg = lp3943_mux_cfg;
124 i2c_set_clientdata(cl, lp3943);
125
126 return devm_mfd_add_devices(dev, -1, lp3943_devs,
127 ARRAY_SIZE(lp3943_devs),
128 NULL, 0, NULL);
129}
130
131static const struct i2c_device_id lp3943_ids[] = {
132 { "lp3943", 0 },
133 { }
134};
135MODULE_DEVICE_TABLE(i2c, lp3943_ids);
136
137#ifdef CONFIG_OF
138static const struct of_device_id lp3943_of_match[] = {
139 { .compatible = "ti,lp3943", },
140 { }
141};
142MODULE_DEVICE_TABLE(of, lp3943_of_match);
143#endif
144
145static struct i2c_driver lp3943_driver = {
146 .probe = lp3943_probe,
147 .driver = {
148 .name = "lp3943",
149 .of_match_table = of_match_ptr(lp3943_of_match),
150 },
151 .id_table = lp3943_ids,
152};
153
154module_i2c_driver(lp3943_driver);
155
156MODULE_DESCRIPTION("LP3943 MFD Core Driver");
157MODULE_AUTHOR("Milo Kim");
158MODULE_LICENSE("GPL");
159