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 mfd_add_devices(dev, -1, lp3943_devs, ARRAY_SIZE(lp3943_devs),
127			       NULL, 0, NULL);
128}
129
130static int lp3943_remove(struct i2c_client *cl)
131{
132	struct lp3943 *lp3943 = i2c_get_clientdata(cl);
133
134	mfd_remove_devices(lp3943->dev);
135	return 0;
136}
137
138static const struct i2c_device_id lp3943_ids[] = {
139	{ "lp3943", 0 },
140	{ }
141};
142MODULE_DEVICE_TABLE(i2c, lp3943_ids);
143
144#ifdef CONFIG_OF
145static const struct of_device_id lp3943_of_match[] = {
146	{ .compatible = "ti,lp3943", },
147	{ }
148};
149MODULE_DEVICE_TABLE(of, lp3943_of_match);
150#endif
151
152static struct i2c_driver lp3943_driver = {
153	.probe = lp3943_probe,
154	.remove = lp3943_remove,
155	.driver = {
156		.name = "lp3943",
157		.of_match_table = of_match_ptr(lp3943_of_match),
158	},
159	.id_table = lp3943_ids,
160};
161
162module_i2c_driver(lp3943_driver);
163
164MODULE_DESCRIPTION("LP3943 MFD Core Driver");
165MODULE_AUTHOR("Milo Kim");
166MODULE_LICENSE("GPL");
167