LXR linux/drivers/gpio/gpio-mc9s08dz60.c

   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        struct mc9s08dz60 *mc9s;
  95
  96        mc9s = devm_kzalloc(&client->dev, sizeof(*mc9s), GFP_KERNEL);
  97        if (!mc9s)
  98                return -ENOMEM;
  99
 100        mc9s->chip.label = client->name;
 101        mc9s->chip.base = -1;
 102        mc9s->chip.dev = &client->dev;
 103        mc9s->chip.owner = THIS_MODULE;
 104        mc9s->chip.ngpio = GPIO_NUM;
 105        mc9s->chip.can_sleep = 1;
 106        mc9s->chip.get = mc9s08dz60_get_value;
 107        mc9s->chip.set = mc9s08dz60_set_value;
 108        mc9s->chip.direction_output = mc9s08dz60_direction_output;
 109        mc9s->client = client;
 110        i2c_set_clientdata(client, mc9s);
 111
 112        return gpiochip_add(&mc9s->chip);
 113}
 114
 115static int mc9s08dz60_remove(struct i2c_client *client)
 116{
 117        struct mc9s08dz60 *mc9s;
 118
 119        mc9s = i2c_get_clientdata(client);
 120
 121        return gpiochip_remove(&mc9s->chip);
 122}
 123
 124static const struct i2c_device_id mc9s08dz60_id[] = {
 125        {"mc9s08dz60", 0},
 126        {},
 127};
 128
 129MODULE_DEVICE_TABLE(i2c, mc9s08dz60_id);
 130
 131static struct i2c_driver mc9s08dz60_i2c_driver = {
 132        .driver = {
 133                .owner = THIS_MODULE,
 134                .name = "mc9s08dz60",
 135        },
 136        .probe = mc9s08dz60_probe,
 137        .remove = mc9s08dz60_remove,
 138        .id_table = mc9s08dz60_id,
 139};
 140
 141module_i2c_driver(mc9s08dz60_i2c_driver);
 142
 143MODULE_AUTHOR("Freescale Semiconductor, Inc. "
 144                "Wu Guoxing <b39297@freescale.com>");
 145MODULE_DESCRIPTION("mc9s08dz60 gpio function on mx35 3ds board");
 146MODULE_LICENSE("GPL v2");
 147