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
  27 struct mc9s08dz60 {
  28         struct i2c_client *client;
  29         struct gpio_chip chip;
  30 };
  31
  32 static inline struct mc9s08dz60 *to_mc9s08dz60(struct gpio_chip *gc)
  33 {
  34         return container_of(gc, struct mc9s08dz60, chip);
  35 }
  36
  37
  38 static 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
  44 static 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
  56 static 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
  76 static 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
  83 static 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
  91 static 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
 124 static 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
 139 static const struct i2c_device_id mc9s08dz60_id[] = {
 140         {"mc9s08dz60", 0},
 141         {},
 142 };
 143
 144 MODULE_DEVICE_TABLE(i2c, mc9s08dz60_id);
 145
 146 static 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
 156 module_i2c_driver(mc9s08dz60_i2c_driver);
 157
 158 MODULE_AUTHOR("Freescale Semiconductor, Inc. "
 159                 "Wu Guoxing <b39297@freescale.com>");
 160 MODULE_DESCRIPTION("mc9s08dz60 gpio function on mx35 3ds board");
 161 MODULE_LICENSE("GPL v2");