1/*
  2 * Copyright 2009-2012 Freescale Semiconductor, Inc. All Rights Reserved.
  3 *
  4 * Author: Wu Guoxing <b39297@freescale.com>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License as published by
  8 * the Free Software Foundation; either version 2 of the License, or
  9 * (at your option) any later version.
 10 *
 11 * This program is distributed in the hope that it will be useful,
 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 * GNU General Public License for more details.
 15 */
 16
 17#include <linux/kernel.h>
 18#include <linux/module.h>
 19#include <linux/slab.h>
 20#include <linux/i2c.h>
 21#include <linux/gpio.h>
 22
 23#define GPIO_GROUP_NUM 2
 24#define GPIO_NUM_PER_GROUP 8
 25#define GPIO_NUM (GPIO_GROUP_NUM*GPIO_NUM_PER_GROUP)
 26
 27struct mc9s08dz60 {
 28	struct i2c_client *client;
 29	struct gpio_chip chip;
 30};
 31
 32static inline struct mc9s08dz60 *to_mc9s08dz60(struct gpio_chip *gc)
 33{
 34	return container_of(gc, struct mc9s08dz60, chip);
 35}
 36
 37
 38static void mc9s_gpio_to_reg_and_bit(int offset, u8 *reg, u8 *bit)
 39{
 40	*reg = 0x20 + offset / GPIO_NUM_PER_GROUP;
 41	*bit = offset % GPIO_NUM_PER_GROUP;
 42}
 43
 44static int mc9s08dz60_get_value(struct gpio_chip *gc, unsigned offset)
 45{
 46	u8 reg, bit;
 47	s32 value;
 48	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
 49
 50	mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
 51	value = i2c_smbus_read_byte_data(mc9s->client, reg);
 52
 53	return (value >= 0) ? (value >> bit) & 0x1 : 0;
 54}
 55
 56static int mc9s08dz60_set(struct mc9s08dz60 *mc9s, unsigned offset, int val)
 57{
 58	u8 reg, bit;
 59	s32 value;
 60
 61	mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
 62	value = i2c_smbus_read_byte_data(mc9s->client, reg);
 63	if (value >= 0) {
 64		if (val)
 65			value |= 1 << bit;
 66		else
 67			value &= ~(1 << bit);
 68
 69		return i2c_smbus_write_byte_data(mc9s->client, reg, value);
 70	} else
 71		return value;
 72
 73}
 74
 75
 76static void mc9s08dz60_set_value(struct gpio_chip *gc, unsigned offset, int val)
 77{
 78	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
 79
 80	mc9s08dz60_set(mc9s, offset, val);
 81}
 82
 83static int mc9s08dz60_direction_output(struct gpio_chip *gc,
 84				       unsigned offset, int val)
 85{
 86	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
 87
 88	return mc9s08dz60_set(mc9s, offset, val);
 89}
 90
 91static int mc9s08dz60_probe(struct i2c_client *client,
 92			    const struct i2c_device_id *id)
 93{
 94	int ret = 0;
 95	struct mc9s08dz60 *mc9s;
 96
 97	mc9s = kzalloc(sizeof(*mc9s), GFP_KERNEL);
 98	if (!mc9s)
 99		return -ENOMEM;
100
101	mc9s->chip.label = client->name;
102	mc9s->chip.base = -1;
103	mc9s->chip.dev = &client->dev;
104	mc9s->chip.owner = THIS_MODULE;
105	mc9s->chip.ngpio = GPIO_NUM;
106	mc9s->chip.can_sleep = 1;
107	mc9s->chip.get = mc9s08dz60_get_value;
108	mc9s->chip.set = mc9s08dz60_set_value;
109	mc9s->chip.direction_output = mc9s08dz60_direction_output;
110	mc9s->client = client;
111	i2c_set_clientdata(client, mc9s);
112
113	ret = gpiochip_add(&mc9s->chip);
114	if (ret)
115		goto error;
116
117	return 0;
118
119 error:
120	kfree(mc9s);
121	return ret;
122}
123
124static int mc9s08dz60_remove(struct i2c_client *client)
125{
126	struct mc9s08dz60 *mc9s;
127	int ret;
128
129	mc9s = i2c_get_clientdata(client);
130
131	ret = gpiochip_remove(&mc9s->chip);
132	if (!ret)
133		kfree(mc9s);
134
135	return ret;
136
137}
138
139static const struct i2c_device_id mc9s08dz60_id[] = {
140	{"mc9s08dz60", 0},
141	{},
142};
143
144MODULE_DEVICE_TABLE(i2c, mc9s08dz60_id);
145
146static struct i2c_driver mc9s08dz60_i2c_driver = {
147	.driver = {
148		.owner = THIS_MODULE,
149		.name = "mc9s08dz60",
150	},
151	.probe = mc9s08dz60_probe,
152	.remove = mc9s08dz60_remove,
153	.id_table = mc9s08dz60_id,
154};
155
156module_i2c_driver(mc9s08dz60_i2c_driver);
157
158MODULE_AUTHOR("Freescale Semiconductor, Inc. "
159		"Wu Guoxing <b39297@freescale.com>");
160MODULE_DESCRIPTION("mc9s08dz60 gpio function on mx35 3ds board");
161MODULE_LICENSE("GPL v2");