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
  27 struct mc9s08dz60 {
  28         struct i2c_client *client;
  29         struct gpio_chip chip;
  30 };
  31
  32 static 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
  38 static 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
  50 static 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
  70 static 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
  77 static 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
  85 static 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
 109 static const struct i2c_device_id mc9s08dz60_id[] = {
 110         {"mc9s08dz60", 0},
 111         {},
 112 };
 113
 114 static struct i2c_driver mc9s08dz60_i2c_driver = {
 115         .driver = {
 116                 .name = "mc9s08dz60",
 117         },
 118         .probe = mc9s08dz60_probe,
 119         .id_table = mc9s08dz60_id,
 120 };
 121 builtin_i2c_driver(mc9s08dz60_i2c_driver);