drivers/i2c/chips/pca9539.c

   1 /*
   2     pca9539.c - 16-bit I/O port with interrupt and reset
   3
   4     Copyright (C) 2005 Ben Gardner <bgardner@wabtec.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; version 2 of the License.
   9 */
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/slab.h>
  14 #include <linux/i2c.h>
  15 #include <linux/hwmon-sysfs.h>
  16
  17 /* Addresses to scan: none, device is not autodetected */
  18 static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
  19
  20 /* Insmod parameters */
  21 I2C_CLIENT_INSMOD_1(pca9539);
  22
  23 enum pca9539_cmd
  24 {
  25         PCA9539_INPUT_0         = 0,
  26         PCA9539_INPUT_1         = 1,
  27         PCA9539_OUTPUT_0        = 2,
  28         PCA9539_OUTPUT_1        = 3,
  29         PCA9539_INVERT_0        = 4,
  30         PCA9539_INVERT_1        = 5,
  31         PCA9539_DIRECTION_0     = 6,
  32         PCA9539_DIRECTION_1     = 7,
  33 };
  34
  35 /* following are the sysfs callback functions */
  36 static ssize_t pca9539_show(struct device *dev, struct device_attribute *attr,
  37                             char *buf)
  38 {
  39         struct sensor_device_attribute *psa = to_sensor_dev_attr(attr);
  40         struct i2c_client *client = to_i2c_client(dev);
  41         return sprintf(buf, "%d\n", i2c_smbus_read_byte_data(client,
  42                                                              psa->index));
  43 }
  44
  45 static ssize_t pca9539_store(struct device *dev, struct device_attribute *attr,
  46                              const char *buf, size_t count)
  47 {
  48         struct sensor_device_attribute *psa = to_sensor_dev_attr(attr);
  49         struct i2c_client *client = to_i2c_client(dev);
  50         unsigned long val = simple_strtoul(buf, NULL, 0);
  51         if (val > 0xff)
  52                 return -EINVAL;
  53         i2c_smbus_write_byte_data(client, psa->index, val);
  54         return count;
  55 }
  56
  57 /* Define the device attributes */
  58
  59 #define PCA9539_ENTRY_RO(name, cmd_idx) \
  60         static SENSOR_DEVICE_ATTR(name, S_IRUGO, pca9539_show, NULL, cmd_idx)
  61
  62 #define PCA9539_ENTRY_RW(name, cmd_idx) \
  63         static SENSOR_DEVICE_ATTR(name, S_IRUGO | S_IWUSR, pca9539_show, \
  64                                   pca9539_store, cmd_idx)
  65
  66 PCA9539_ENTRY_RO(input0, PCA9539_INPUT_0);
  67 PCA9539_ENTRY_RO(input1, PCA9539_INPUT_1);
  68 PCA9539_ENTRY_RW(output0, PCA9539_OUTPUT_0);
  69 PCA9539_ENTRY_RW(output1, PCA9539_OUTPUT_1);
  70 PCA9539_ENTRY_RW(invert0, PCA9539_INVERT_0);
  71 PCA9539_ENTRY_RW(invert1, PCA9539_INVERT_1);
  72 PCA9539_ENTRY_RW(direction0, PCA9539_DIRECTION_0);
  73 PCA9539_ENTRY_RW(direction1, PCA9539_DIRECTION_1);
  74
  75 static struct attribute *pca9539_attributes[] = {
  76         &sensor_dev_attr_input0.dev_attr.attr,
  77         &sensor_dev_attr_input1.dev_attr.attr,
  78         &sensor_dev_attr_output0.dev_attr.attr,
  79         &sensor_dev_attr_output1.dev_attr.attr,
  80         &sensor_dev_attr_invert0.dev_attr.attr,
  81         &sensor_dev_attr_invert1.dev_attr.attr,
  82         &sensor_dev_attr_direction0.dev_attr.attr,
  83         &sensor_dev_attr_direction1.dev_attr.attr,
  84         NULL
  85 };
  86
  87 static struct attribute_group pca9539_defattr_group = {
  88         .attrs = pca9539_attributes,
  89 };
  90
  91 /* Return 0 if detection is successful, -ENODEV otherwise */
  92 static int pca9539_detect(struct i2c_client *client, int kind,
  93                           struct i2c_board_info *info)
  94 {
  95         struct i2c_adapter *adapter = client->adapter;
  96
  97         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  98                 return -ENODEV;
  99
 100         strlcpy(info->type, "pca9539", I2C_NAME_SIZE);
 101
 102         return 0;
 103 }
 104
 105 static int pca9539_probe(struct i2c_client *client,
 106                          const struct i2c_device_id *id)
 107 {
 108         /* Register sysfs hooks */
 109         return sysfs_create_group(&client->dev.kobj,
 110                                   &pca9539_defattr_group);
 111 }
 112
 113 static int pca9539_remove(struct i2c_client *client)
 114 {
 115         sysfs_remove_group(&client->dev.kobj, &pca9539_defattr_group);
 116         return 0;
 117 }
 118
 119 static const struct i2c_device_id pca9539_id[] = {
 120         { "pca9539", 0 },
 121         { }
 122 };
 123
 124 static struct i2c_driver pca9539_driver = {
 125         .driver = {
 126                 .name   = "pca9539",
 127         },
 128         .probe          = pca9539_probe,
 129         .remove         = pca9539_remove,
 130         .id_table       = pca9539_id,
 131
 132         .detect         = pca9539_detect,
 133         .address_data   = &addr_data,
 134 };
 135
 136 static int __init pca9539_init(void)
 137 {
 138         return i2c_add_driver(&pca9539_driver);
 139 }
 140
 141 static void __exit pca9539_exit(void)
 142 {
 143         i2c_del_driver(&pca9539_driver);
 144 }
 145
 146 MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
 147 MODULE_DESCRIPTION("PCA9539 driver");
 148 MODULE_LICENSE("GPL");
 149
 150 module_init(pca9539_init);
 151 module_exit(pca9539_exit);
 152