drivers/media/video/hdpvr/hdpvr-i2c.c

   1
   2 /*
   3  * Hauppauge HD PVR USB driver
   4  *
   5  * Copyright (C) 2008      Janne Grunau (j@jannau.net)
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License as
   9  *      published by the Free Software Foundation, version 2.
  10  *
  11  */
  12
  13 #include <linux/i2c.h>
  14 #include <linux/slab.h>
  15
  16 #include "hdpvr.h"
  17
  18 #define CTRL_READ_REQUEST       0xb8
  19 #define CTRL_WRITE_REQUEST      0x38
  20
  21 #define REQTYPE_I2C_READ        0xb1
  22 #define REQTYPE_I2C_WRITE       0xb0
  23 #define REQTYPE_I2C_WRITE_STATT 0xd0
  24
  25 static int hdpvr_i2c_read(struct hdpvr_device *dev, unsigned char addr,
  26                           char *data, int len)
  27 {
  28         int ret;
  29         char *buf = kmalloc(len, GFP_KERNEL);
  30         if (!buf)
  31                 return -ENOMEM;
  32
  33         ret = usb_control_msg(dev->udev,
  34                               usb_rcvctrlpipe(dev->udev, 0),
  35                               REQTYPE_I2C_READ, CTRL_READ_REQUEST,
  36                               0x100|addr, 0, buf, len, 1000);
  37
  38         if (ret == len) {
  39                 memcpy(data, buf, len);
  40                 ret = 0;
  41         } else if (ret >= 0)
  42                 ret = -EIO;
  43
  44         kfree(buf);
  45
  46         return ret;
  47 }
  48
  49 static int hdpvr_i2c_write(struct hdpvr_device *dev, unsigned char addr,
  50                            char *data, int len)
  51 {
  52         int ret;
  53         char *buf = kmalloc(len, GFP_KERNEL);
  54         if (!buf)
  55                 return -ENOMEM;
  56
  57         memcpy(buf, data, len);
  58         ret = usb_control_msg(dev->udev,
  59                               usb_sndctrlpipe(dev->udev, 0),
  60                               REQTYPE_I2C_WRITE, CTRL_WRITE_REQUEST,
  61                               0x100|addr, 0, buf, len, 1000);
  62
  63         if (ret < 0)
  64                 goto error;
  65
  66         ret = usb_control_msg(dev->udev,
  67                               usb_rcvctrlpipe(dev->udev, 0),
  68                               REQTYPE_I2C_WRITE_STATT, CTRL_READ_REQUEST,
  69                               0, 0, buf, 2, 1000);
  70
  71         if (ret == 2)
  72                 ret = 0;
  73         else if (ret >= 0)
  74                 ret = -EIO;
  75
  76 error:
  77         kfree(buf);
  78         return ret;
  79 }
  80
  81 static int hdpvr_transfer(struct i2c_adapter *i2c_adapter, struct i2c_msg *msgs,
  82                           int num)
  83 {
  84         struct hdpvr_device *dev = i2c_get_adapdata(i2c_adapter);
  85         int retval = 0, i, addr;
  86
  87         if (num <= 0)
  88                 return 0;
  89
  90         mutex_lock(&dev->i2c_mutex);
  91
  92         for (i = 0; i < num && !retval; i++) {
  93                 addr = msgs[i].addr << 1;
  94
  95                 if (msgs[i].flags & I2C_M_RD)
  96                         retval = hdpvr_i2c_read(dev, addr, msgs[i].buf,
  97                                                 msgs[i].len);
  98                 else
  99                         retval = hdpvr_i2c_write(dev, addr, msgs[i].buf,
 100                                                  msgs[i].len);
 101         }
 102
 103         mutex_unlock(&dev->i2c_mutex);
 104
 105         return retval ? retval : num;
 106 }
 107
 108 static u32 hdpvr_functionality(struct i2c_adapter *adapter)
 109 {
 110         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 111 }
 112
 113 static struct i2c_algorithm hdpvr_algo = {
 114         .master_xfer   = hdpvr_transfer,
 115         .functionality = hdpvr_functionality,
 116 };
 117
 118 int hdpvr_register_i2c_adapter(struct hdpvr_device *dev)
 119 {
 120         struct i2c_adapter *i2c_adap;
 121         int retval = -ENOMEM;
 122
 123         i2c_adap = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
 124         if (i2c_adap == NULL)
 125                 goto error;
 126
 127         strlcpy(i2c_adap->name, "Hauppauge HD PVR I2C",
 128                 sizeof(i2c_adap->name));
 129         i2c_adap->algo  = &hdpvr_algo;
 130         i2c_adap->owner = THIS_MODULE;
 131         i2c_adap->dev.parent = &dev->udev->dev;
 132
 133         i2c_set_adapdata(i2c_adap, dev);
 134
 135         retval = i2c_add_adapter(i2c_adap);
 136
 137         if (!retval)
 138                 dev->i2c_adapter = i2c_adap;
 139         else
 140                 kfree(i2c_adap);
 141
 142 error:
 143         return retval;
 144 }