root/drivers/gpio/gpio-mc9s08dz60.c

DEFINITIONS

1. mc9s_gpio_to_reg_and_bit
2. mc9s08dz60_get_value
3. mc9s08dz60_set
4. mc9s08dz60_set_value
5. mc9s08dz60_direction_output
6. mc9s08dz60_probe

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2009-2012 Freescale Semiconductor, Inc. All Rights Reserved.
   4  *
   5  * Author: Wu Guoxing <b39297@freescale.com>
   6  */
   7 
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/i2c.h>
  12 #include <linux/gpio/driver.h>
  13 
  14 #define GPIO_GROUP_NUM 2
  15 #define GPIO_NUM_PER_GROUP 8
  16 #define GPIO_NUM (GPIO_GROUP_NUM*GPIO_NUM_PER_GROUP)
  17 
  18 struct mc9s08dz60 {
  19         struct i2c_client *client;
  20         struct gpio_chip chip;
  21 };
  22 
  23 static void mc9s_gpio_to_reg_and_bit(int offset, u8 *reg, u8 *bit)
  24 {
  25         *reg = 0x20 + offset / GPIO_NUM_PER_GROUP;
  26         *bit = offset % GPIO_NUM_PER_GROUP;
  27 }
  28 
  29 static int mc9s08dz60_get_value(struct gpio_chip *gc, unsigned offset)
  30 {
  31         u8 reg, bit;
  32         s32 value;
  33         struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
  34 
  35         mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
  36         value = i2c_smbus_read_byte_data(mc9s->client, reg);
  37 
  38         return (value >= 0) ? (value >> bit) & 0x1 : 0;
  39 }
  40 
  41 static int mc9s08dz60_set(struct mc9s08dz60 *mc9s, unsigned offset, int val)
  42 {
  43         u8 reg, bit;
  44         s32 value;
  45 
  46         mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
  47         value = i2c_smbus_read_byte_data(mc9s->client, reg);
  48         if (value >= 0) {
  49                 if (val)
  50                         value |= 1 << bit;
  51                 else
  52                         value &= ~(1 << bit);
  53 
  54                 return i2c_smbus_write_byte_data(mc9s->client, reg, value);
  55         } else
  56                 return value;
  57 
  58 }
  59 
  60 
  61 static void mc9s08dz60_set_value(struct gpio_chip *gc, unsigned offset, int val)
  62 {
  63         struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
  64 
  65         mc9s08dz60_set(mc9s, offset, val);
  66 }
  67 
  68 static int mc9s08dz60_direction_output(struct gpio_chip *gc,
  69                                        unsigned offset, int val)
  70 {
  71         struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
  72 
  73         return mc9s08dz60_set(mc9s, offset, val);
  74 }
  75 
  76 static int mc9s08dz60_probe(struct i2c_client *client,
  77                             const struct i2c_device_id *id)
  78 {
  79         struct mc9s08dz60 *mc9s;
  80 
  81         mc9s = devm_kzalloc(&client->dev, sizeof(*mc9s), GFP_KERNEL);
  82         if (!mc9s)
  83                 return -ENOMEM;
  84 
  85         mc9s->chip.label = client->name;
  86         mc9s->chip.base = -1;
  87         mc9s->chip.parent = &client->dev;
  88         mc9s->chip.owner = THIS_MODULE;
  89         mc9s->chip.ngpio = GPIO_NUM;
  90         mc9s->chip.can_sleep = true;
  91         mc9s->chip.get = mc9s08dz60_get_value;
  92         mc9s->chip.set = mc9s08dz60_set_value;
  93         mc9s->chip.direction_output = mc9s08dz60_direction_output;
  94         mc9s->client = client;
  95         i2c_set_clientdata(client, mc9s);
  96 
  97         return devm_gpiochip_add_data(&client->dev, &mc9s->chip, mc9s);
  98 }
  99 
 100 static const struct i2c_device_id mc9s08dz60_id[] = {
 101         {"mc9s08dz60", 0},
 102         {},
 103 };
 104 
 105 static struct i2c_driver mc9s08dz60_i2c_driver = {
 106         .driver = {
 107                 .name = "mc9s08dz60",
 108         },
 109         .probe = mc9s08dz60_probe,
 110         .id_table = mc9s08dz60_id,
 111 };
 112 builtin_i2c_driver(mc9s08dz60_i2c_driver);