arch/arm/mach-pxa/akita-ioexp.c

   1 /*
   2  * Support for the Extra GPIOs on the Sharp SL-C1000 (Akita)
   3  * (uses a Maxim MAX7310 8 Port IO Expander)
   4  *
   5  * Copyright 2005 Openedhand Ltd.
   6  *
   7  * Author: Richard Purdie <richard@openedhand.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/module.h>
  19 #include <linux/i2c.h>
  20 #include <linux/slab.h>
  21 #include <linux/workqueue.h>
  22 #include <mach/akita.h>
  23
  24 /* MAX7310 Regiser Map */
  25 #define MAX7310_INPUT    0x00
  26 #define MAX7310_OUTPUT   0x01
  27 #define MAX7310_POLINV   0x02
  28 #define MAX7310_IODIR    0x03 /* 1 = Input, 0 = Output */
  29 #define MAX7310_TIMEOUT  0x04
  30
  31 /* Addresses to scan */
  32 static const unsigned short normal_i2c[] = { 0x18, I2C_CLIENT_END };
  33
  34 /* I2C Magic */
  35 I2C_CLIENT_INSMOD;
  36
  37 static int max7310_write(struct i2c_client *client, int address, int data);
  38 static struct i2c_client max7310_template;
  39 static void akita_ioexp_work(struct work_struct *private_);
  40
  41 static struct device *akita_ioexp_device;
  42 static unsigned char ioexp_output_value = AKITA_IOEXP_IO_OUT;
  43 DECLARE_WORK(akita_ioexp, akita_ioexp_work);
  44
  45
  46 /*
  47  * MAX7310 Access
  48  */
  49 static int max7310_config(struct device *dev, int iomode, int polarity)
  50 {
  51         int ret;
  52         struct i2c_client *client = to_i2c_client(dev);
  53
  54         ret = max7310_write(client, MAX7310_POLINV, polarity);
  55         if (ret < 0)
  56                 return ret;
  57         ret = max7310_write(client, MAX7310_IODIR, iomode);
  58         return ret;
  59 }
  60
  61 static int max7310_set_ouputs(struct device *dev, int outputs)
  62 {
  63         struct i2c_client *client = to_i2c_client(dev);
  64
  65         return max7310_write(client, MAX7310_OUTPUT, outputs);
  66 }
  67
  68 /*
  69  * I2C Functions
  70  */
  71 static int max7310_write(struct i2c_client *client, int address, int value)
  72 {
  73         u8 data[2];
  74
  75         data[0] = address & 0xff;
  76         data[1] = value & 0xff;
  77
  78         if (i2c_master_send(client, data, 2) == 2)
  79                 return 0;
  80         return -1;
  81 }
  82
  83 static int max7310_detect(struct i2c_adapter *adapter, int address, int kind)
  84 {
  85         struct i2c_client *new_client;
  86         int err;
  87
  88         if (!(new_client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL)))
  89                 return -ENOMEM;
  90
  91         max7310_template.adapter = adapter;
  92         max7310_template.addr = address;
  93
  94         memcpy(new_client, &max7310_template, sizeof(struct i2c_client));
  95
  96         if ((err = i2c_attach_client(new_client))) {
  97                 kfree(new_client);
  98                 return err;
  99         }
 100
 101         max7310_config(&new_client->dev, AKITA_IOEXP_IO_DIR, 0);
 102         akita_ioexp_device = &new_client->dev;
 103         schedule_work(&akita_ioexp);
 104
 105         return 0;
 106 }
 107
 108 static int max7310_attach_adapter(struct i2c_adapter *adapter)
 109 {
 110         return i2c_probe(adapter, &addr_data, max7310_detect);
 111 }
 112
 113 static int max7310_detach_client(struct i2c_client *client)
 114 {
 115         int err;
 116
 117         akita_ioexp_device = NULL;
 118
 119         if ((err = i2c_detach_client(client)))
 120                 return err;
 121
 122         kfree(client);
 123         return 0;
 124 }
 125
 126 static struct i2c_driver max7310_i2c_driver = {
 127         .driver = {
 128                 .name   = "akita-max7310",
 129         },
 130         .id             = I2C_DRIVERID_AKITAIOEXP,
 131         .attach_adapter = max7310_attach_adapter,
 132         .detach_client  = max7310_detach_client,
 133 };
 134
 135 static struct i2c_client max7310_template = {
 136         name:   "akita-max7310",
 137         driver: &max7310_i2c_driver,
 138 };
 139
 140 void akita_set_ioexp(struct device *dev, unsigned char bit)
 141 {
 142         ioexp_output_value |= bit;
 143
 144         if (akita_ioexp_device)
 145                 schedule_work(&akita_ioexp);
 146         return;
 147 }
 148
 149 void akita_reset_ioexp(struct device *dev, unsigned char bit)
 150 {
 151         ioexp_output_value &= ~bit;
 152
 153         if (akita_ioexp_device)
 154                 schedule_work(&akita_ioexp);
 155         return;
 156 }
 157
 158 EXPORT_SYMBOL(akita_set_ioexp);
 159 EXPORT_SYMBOL(akita_reset_ioexp);
 160
 161 static void akita_ioexp_work(struct work_struct *private_)
 162 {
 163         if (akita_ioexp_device)
 164                 max7310_set_ouputs(akita_ioexp_device, ioexp_output_value);
 165 }
 166
 167
 168 #ifdef CONFIG_PM
 169 static int akita_ioexp_suspend(struct platform_device *pdev, pm_message_t state)
 170 {
 171         flush_scheduled_work();
 172         return 0;
 173 }
 174
 175 static int akita_ioexp_resume(struct platform_device *pdev)
 176 {
 177         schedule_work(&akita_ioexp);
 178         return 0;
 179 }
 180 #else
 181 #define akita_ioexp_suspend NULL
 182 #define akita_ioexp_resume NULL
 183 #endif
 184
 185 static int __init akita_ioexp_probe(struct platform_device *pdev)
 186 {
 187         return i2c_add_driver(&max7310_i2c_driver);
 188 }
 189
 190 static int akita_ioexp_remove(struct platform_device *pdev)
 191 {
 192         i2c_del_driver(&max7310_i2c_driver);
 193         return 0;
 194 }
 195
 196 static struct platform_driver akita_ioexp_driver = {
 197         .probe          = akita_ioexp_probe,
 198         .remove         = akita_ioexp_remove,
 199         .suspend        = akita_ioexp_suspend,
 200         .resume         = akita_ioexp_resume,
 201         .driver         = {
 202                 .name   = "akita-ioexp",
 203         },
 204 };
 205
 206 static int __init akita_ioexp_init(void)
 207 {
 208         return platform_driver_register(&akita_ioexp_driver);
 209 }
 210
 211 static void __exit akita_ioexp_exit(void)
 212 {
 213         platform_driver_unregister(&akita_ioexp_driver);
 214 }
 215
 216 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 217 MODULE_DESCRIPTION("Akita IO-Expander driver");
 218 MODULE_LICENSE("GPL");
 219
 220 fs_initcall(akita_ioexp_init);
 221 module_exit(akita_ioexp_exit);
 222