i2c-robotfuzz-osif.c
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/*
* Driver for RobotFuzz OSIF
*
* Copyright (c) 2013 Andrew Lunn <andrew@lunn.ch>
* Copyright (c) 2007 Barry Carter <Barry.Carter@robotfuzz.com>
*
* Based on the i2c-tiny-usb by
*
* Copyright (C) 2006 Til Harbaum (Till@Harbaum.org)
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/usb.h>
#define OSIFI2C_READ 20
#define OSIFI2C_WRITE 21
#define OSIFI2C_STOP 22
#define OSIFI2C_STATUS 23
#define OSIFI2C_SET_BIT_RATE 24
#define STATUS_ADDRESS_ACK 0
#define STATUS_ADDRESS_NAK 2
struct osif_priv {
struct usb_device *usb_dev;
struct usb_interface *interface;
struct i2c_adapter adapter;
unsigned char status;
};
static int osif_usb_read(struct i2c_adapter *adapter, int cmd,
int value, int index, void *data, int len)
{
struct osif_priv *priv = adapter->algo_data;
return usb_control_msg(priv->usb_dev, usb_rcvctrlpipe(priv->usb_dev, 0),
cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE |
USB_DIR_IN, value, index, data, len, 2000);
}
static int osif_usb_write(struct i2c_adapter *adapter, int cmd,
int value, int index, void *data, int len)
{
struct osif_priv *priv = adapter->algo_data;
return usb_control_msg(priv->usb_dev, usb_sndctrlpipe(priv->usb_dev, 0),
cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
value, index, data, len, 2000);
}
static int osif_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
int num)
{
struct osif_priv *priv = adapter->algo_data;
struct i2c_msg *pmsg;
int ret = 0;
int i, cmd;
for (i = 0; ret >= 0 && i < num; i++) {
pmsg = &msgs[i];
if (pmsg->flags & I2C_M_RD) {
cmd = OSIFI2C_READ;
ret = osif_usb_read(adapter, cmd, pmsg->flags,
pmsg->addr, pmsg->buf,
pmsg->len);
if (ret != pmsg->len) {
dev_err(&adapter->dev, "failure reading data\n");
return -EREMOTEIO;
}
} else {
cmd = OSIFI2C_WRITE;
ret = osif_usb_write(adapter, cmd, pmsg->flags,
pmsg->addr, pmsg->buf, pmsg->len);
if (ret != pmsg->len) {
dev_err(&adapter->dev, "failure writing data\n");
return -EREMOTEIO;
}
}
ret = osif_usb_read(adapter, OSIFI2C_STOP, 0, 0, NULL, 0);
if (ret) {
dev_err(&adapter->dev, "failure sending STOP\n");
return -EREMOTEIO;
}
/* read status */
ret = osif_usb_read(adapter, OSIFI2C_STATUS, 0, 0,
&priv->status, 1);
if (ret != 1) {
dev_err(&adapter->dev, "failure reading status\n");
return -EREMOTEIO;
}
if (priv->status != STATUS_ADDRESS_ACK) {
dev_dbg(&adapter->dev, "status = %d\n", priv->status);
return -EREMOTEIO;
}
}
return i;
}
static u32 osif_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static struct i2c_algorithm osif_algorithm = {
.master_xfer = osif_xfer,
.functionality = osif_func,
};
#define USB_OSIF_VENDOR_ID 0x1964
#define USB_OSIF_PRODUCT_ID 0x0001
static struct usb_device_id osif_table[] = {
{ USB_DEVICE(USB_OSIF_VENDOR_ID, USB_OSIF_PRODUCT_ID) },
{ }
};
MODULE_DEVICE_TABLE(usb, osif_table);
static int osif_probe(struct usb_interface *interface,
const struct usb_device_id *id)
{
int ret;
struct osif_priv *priv;
u16 version;
priv = devm_kzalloc(&interface->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->usb_dev = usb_get_dev(interface_to_usbdev(interface));
priv->interface = interface;
usb_set_intfdata(interface, priv);
priv->adapter.owner = THIS_MODULE;
priv->adapter.class = I2C_CLASS_HWMON;
priv->adapter.algo = &osif_algorithm;
priv->adapter.algo_data = priv;
snprintf(priv->adapter.name, sizeof(priv->adapter.name),
"OSIF at bus %03d device %03d",
priv->usb_dev->bus->busnum, priv->usb_dev->devnum);
/*
* Set bus frequency. The frequency is:
* 120,000,000 / ( 16 + 2 * div * 4^prescale).
* Using dev = 52, prescale = 0 give 100KHz */
ret = osif_usb_read(&priv->adapter, OSIFI2C_SET_BIT_RATE, 52, 0,
NULL, 0);
if (ret) {
dev_err(&interface->dev, "failure sending bit rate");
usb_put_dev(priv->usb_dev);
return ret;
}
i2c_add_adapter(&(priv->adapter));
version = le16_to_cpu(priv->usb_dev->descriptor.bcdDevice);
dev_info(&interface->dev,
"version %x.%02x found at bus %03d address %03d",
version >> 8, version & 0xff,
priv->usb_dev->bus->busnum, priv->usb_dev->devnum);
return 0;
}
static void osif_disconnect(struct usb_interface *interface)
{
struct osif_priv *priv = usb_get_intfdata(interface);
i2c_del_adapter(&(priv->adapter));
usb_set_intfdata(interface, NULL);
usb_put_dev(priv->usb_dev);
}
static struct usb_driver osif_driver = {
.name = "RobotFuzz Open Source InterFace, OSIF",
.probe = osif_probe,
.disconnect = osif_disconnect,
.id_table = osif_table,
};
module_usb_driver(osif_driver);
MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
MODULE_AUTHOR("Barry Carter <barry.carter@robotfuzz.com>");
MODULE_DESCRIPTION("RobotFuzz OSIF driver");
MODULE_LICENSE("GPL v2");