/drivers/media/video/hdpvr/hdpvr-i2c.c
https://bitbucket.org/abioy/linux · C · 145 lines · 103 code · 32 blank · 10 comment · 18 complexity · 30203acb58aa1f42f1bf0eba159c7b6a MD5 · raw file
- /*
- * Hauppauge HD PVR USB driver
- *
- * Copyright (C) 2008 Janne Grunau (j@jannau.net)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation, version 2.
- *
- */
- #include <linux/i2c.h>
- #include <linux/slab.h>
- #include "hdpvr.h"
- #define CTRL_READ_REQUEST 0xb8
- #define CTRL_WRITE_REQUEST 0x38
- #define REQTYPE_I2C_READ 0xb1
- #define REQTYPE_I2C_WRITE 0xb0
- #define REQTYPE_I2C_WRITE_STATT 0xd0
- static int hdpvr_i2c_read(struct hdpvr_device *dev, unsigned char addr,
- char *data, int len)
- {
- int ret;
- char *buf = kmalloc(len, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
- ret = usb_control_msg(dev->udev,
- usb_rcvctrlpipe(dev->udev, 0),
- REQTYPE_I2C_READ, CTRL_READ_REQUEST,
- 0x100|addr, 0, buf, len, 1000);
- if (ret == len) {
- memcpy(data, buf, len);
- ret = 0;
- } else if (ret >= 0)
- ret = -EIO;
- kfree(buf);
- return ret;
- }
- static int hdpvr_i2c_write(struct hdpvr_device *dev, unsigned char addr,
- char *data, int len)
- {
- int ret;
- char *buf = kmalloc(len, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
- memcpy(buf, data, len);
- ret = usb_control_msg(dev->udev,
- usb_sndctrlpipe(dev->udev, 0),
- REQTYPE_I2C_WRITE, CTRL_WRITE_REQUEST,
- 0x100|addr, 0, buf, len, 1000);
- if (ret < 0)
- goto error;
- ret = usb_control_msg(dev->udev,
- usb_rcvctrlpipe(dev->udev, 0),
- REQTYPE_I2C_WRITE_STATT, CTRL_READ_REQUEST,
- 0, 0, buf, 2, 1000);
- if (ret == 2)
- ret = 0;
- else if (ret >= 0)
- ret = -EIO;
- error:
- kfree(buf);
- return ret;
- }
- static int hdpvr_transfer(struct i2c_adapter *i2c_adapter, struct i2c_msg *msgs,
- int num)
- {
- struct hdpvr_device *dev = i2c_get_adapdata(i2c_adapter);
- int retval = 0, i, addr;
- if (num <= 0)
- return 0;
- mutex_lock(&dev->i2c_mutex);
- for (i = 0; i < num && !retval; i++) {
- addr = msgs[i].addr << 1;
- if (msgs[i].flags & I2C_M_RD)
- retval = hdpvr_i2c_read(dev, addr, msgs[i].buf,
- msgs[i].len);
- else
- retval = hdpvr_i2c_write(dev, addr, msgs[i].buf,
- msgs[i].len);
- }
- mutex_unlock(&dev->i2c_mutex);
- return retval ? retval : num;
- }
- static u32 hdpvr_functionality(struct i2c_adapter *adapter)
- {
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
- }
- static struct i2c_algorithm hdpvr_algo = {
- .master_xfer = hdpvr_transfer,
- .functionality = hdpvr_functionality,
- };
- int hdpvr_register_i2c_adapter(struct hdpvr_device *dev)
- {
- struct i2c_adapter *i2c_adap;
- int retval = -ENOMEM;
- i2c_adap = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
- if (i2c_adap == NULL)
- goto error;
- strlcpy(i2c_adap->name, "Hauppauge HD PVR I2C",
- sizeof(i2c_adap->name));
- i2c_adap->algo = &hdpvr_algo;
- i2c_adap->class = I2C_CLASS_TV_ANALOG;
- i2c_adap->owner = THIS_MODULE;
- i2c_adap->dev.parent = &dev->udev->dev;
- i2c_set_adapdata(i2c_adap, dev);
- retval = i2c_add_adapter(i2c_adap);
- if (!retval)
- dev->i2c_adapter = i2c_adap;
- else
- kfree(i2c_adap);
- error:
- return retval;
- }