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 void mc9s_gpio_to_reg_and_bit(int offset, u8 *reg, u8 *bit)
 33{
 34	*reg = 0x20 + offset / GPIO_NUM_PER_GROUP;
 35	*bit = offset % GPIO_NUM_PER_GROUP;
 36}
 37
 38static int mc9s08dz60_get_value(struct gpio_chip *gc, unsigned offset)
 39{
 40	u8 reg, bit;
 41	s32 value;
 42	struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
 43
 44	mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
 45	value = i2c_smbus_read_byte_data(mc9s->client, reg);
 46
 47	return (value >= 0) ? (value >> bit) & 0x1 : 0;
 48}
 49
 50static int mc9s08dz60_set(struct mc9s08dz60 *mc9s, unsigned offset, int val)
 51{
 52	u8 reg, bit;
 53	s32 value;
 54
 55	mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
 56	value = i2c_smbus_read_byte_data(mc9s->client, reg);
 57	if (value >= 0) {
 58		if (val)
 59			value |= 1 << bit;
 60		else
 61			value &= ~(1 << bit);
 62
 63		return i2c_smbus_write_byte_data(mc9s->client, reg, value);
 64	} else
 65		return value;
 66
 67}
 68
 69
 70static void mc9s08dz60_set_value(struct gpio_chip *gc, unsigned offset, int val)
 71{
 72	struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
 73
 74	mc9s08dz60_set(mc9s, offset, val);
 75}
 76
 77static int mc9s08dz60_direction_output(struct gpio_chip *gc,
 78				       unsigned offset, int val)
 79{
 80	struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
 81
 82	return mc9s08dz60_set(mc9s, offset, val);
 83}
 84
 85static int mc9s08dz60_probe(struct i2c_client *client,
 86			    const struct i2c_device_id *id)
 87{
 88	struct mc9s08dz60 *mc9s;
 89
 90	mc9s = devm_kzalloc(&client->dev, sizeof(*mc9s), GFP_KERNEL);
 91	if (!mc9s)
 92		return -ENOMEM;
 93
 94	mc9s->chip.label = client->name;
 95	mc9s->chip.base = -1;
 96	mc9s->chip.parent = &client->dev;
 97	mc9s->chip.owner = THIS_MODULE;
 98	mc9s->chip.ngpio = GPIO_NUM;
 99	mc9s->chip.can_sleep = true;
100	mc9s->chip.get = mc9s08dz60_get_value;
101	mc9s->chip.set = mc9s08dz60_set_value;
102	mc9s->chip.direction_output = mc9s08dz60_direction_output;
103	mc9s->client = client;
104	i2c_set_clientdata(client, mc9s);
105
106	return devm_gpiochip_add_data(&client->dev, &mc9s->chip, mc9s);
107}
108
109static const struct i2c_device_id mc9s08dz60_id[] = {
110	{"mc9s08dz60", 0},
111	{},
112};
113
114MODULE_DEVICE_TABLE(i2c, mc9s08dz60_id);
115
116static struct i2c_driver mc9s08dz60_i2c_driver = {
117	.driver = {
118		.name = "mc9s08dz60",
119	},
120	.probe = mc9s08dz60_probe,
121	.id_table = mc9s08dz60_id,
122};
123
124module_i2c_driver(mc9s08dz60_i2c_driver);
125
126MODULE_AUTHOR("Freescale Semiconductor, Inc. "
127		"Wu Guoxing <b39297@freescale.com>");
128MODULE_DESCRIPTION("mc9s08dz60 gpio function on mx35 3ds board");
129MODULE_LICENSE("GPL v2");