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/init.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
 114static struct i2c_driver mc9s08dz60_i2c_driver = {
 115        .driver = {
 116                .name = "mc9s08dz60",
 117        },
 118        .probe = mc9s08dz60_probe,
 119        .id_table = mc9s08dz60_id,
 120};
 121builtin_i2c_driver(mc9s08dz60_i2c_driver);
 122