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
  15 #include "hdpvr.h"
  16
  17 #define CTRL_READ_REQUEST       0xb8
  18 #define CTRL_WRITE_REQUEST      0x38
  19
  20 #define REQTYPE_I2C_READ        0xb1
  21 #define REQTYPE_I2C_WRITE       0xb0
  22 #define REQTYPE_I2C_WRITE_STATT 0xd0
  23
  24 static int hdpvr_i2c_read(struct hdpvr_device *dev, unsigned char addr,
  25                           char *data, int len)
  26 {
  27         int ret;
  28         char *buf = kmalloc(len, GFP_KERNEL);
  29         if (!buf)
  30                 return -ENOMEM;
  31
  32         ret = usb_control_msg(dev->udev,
  33                               usb_rcvctrlpipe(dev->udev, 0),
  34                               REQTYPE_I2C_READ, CTRL_READ_REQUEST,
  35                               0x100|addr, 0, buf, len, 1000);
  36
  37         if (ret == len) {
  38                 memcpy(data, buf, len);
  39                 ret = 0;
  40         } else if (ret >= 0)
  41                 ret = -EIO;
  42
  43         kfree(buf);
  44
  45         return ret;
  46 }
  47
  48 static int hdpvr_i2c_write(struct hdpvr_device *dev, unsigned char addr,
  49                            char *data, int len)
  50 {
  51         int ret;
  52         char *buf = kmalloc(len, GFP_KERNEL);
  53         if (!buf)
  54                 return -ENOMEM;
  55
  56         memcpy(buf, data, len);
  57         ret = usb_control_msg(dev->udev,
  58                               usb_sndctrlpipe(dev->udev, 0),
  59                               REQTYPE_I2C_WRITE, CTRL_WRITE_REQUEST,
  60                               0x100|addr, 0, buf, len, 1000);
  61
  62         if (ret < 0)
  63                 goto error;
  64
  65         ret = usb_control_msg(dev->udev,
  66                               usb_rcvctrlpipe(dev->udev, 0),
  67                               REQTYPE_I2C_WRITE_STATT, CTRL_READ_REQUEST,
  68                               0, 0, buf, 2, 1000);
  69
  70         if (ret == 2)
  71                 ret = 0;
  72         else if (ret >= 0)
  73                 ret = -EIO;
  74
  75 error:
  76         kfree(buf);
  77         return ret;
  78 }
  79
  80 static int hdpvr_transfer(struct i2c_adapter *i2c_adapter, struct i2c_msg *msgs,
  81                           int num)
  82 {
  83         struct hdpvr_device *dev = i2c_get_adapdata(i2c_adapter);
  84         int retval = 0, i, addr;
  85
  86         if (num <= 0)
  87                 return 0;
  88
  89         mutex_lock(&dev->i2c_mutex);
  90
  91         for (i = 0; i < num && !retval; i++) {
  92                 addr = msgs[i].addr << 1;
  93
  94                 if (msgs[i].flags & I2C_M_RD)
  95                         retval = hdpvr_i2c_read(dev, addr, msgs[i].buf,
  96                                                 msgs[i].len);
  97                 else
  98                         retval = hdpvr_i2c_write(dev, addr, msgs[i].buf,
  99                                                  msgs[i].len);
 100         }
 101
 102         mutex_unlock(&dev->i2c_mutex);
 103
 104         return retval ? retval : num;
 105 }
 106
 107 static u32 hdpvr_functionality(struct i2c_adapter *adapter)
 108 {
 109         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 110 }
 111
 112 static struct i2c_algorithm hdpvr_algo = {
 113         .master_xfer   = hdpvr_transfer,
 114         .functionality = hdpvr_functionality,
 115 };
 116
 117 int hdpvr_register_i2c_adapter(struct hdpvr_device *dev)
 118 {
 119         struct i2c_adapter *i2c_adap;
 120         int retval = -ENOMEM;
 121
 122         i2c_adap = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
 123         if (i2c_adap == NULL)
 124                 goto error;
 125
 126         strlcpy(i2c_adap->name, "Hauppauge HD PVR I2C",
 127                 sizeof(i2c_adap->name));
 128         i2c_adap->algo  = &hdpvr_algo;
 129         i2c_adap->class = I2C_CLASS_TV_ANALOG;
 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 }