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kernel/linux-imx6_3.14.28/drivers/i2c/busses/i2c-robotfuzz-osif.c 5.06 KB
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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
  ");
  				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
  ");
  				return -EREMOTEIO;
  			}
  		}
  
  		ret = osif_usb_read(adapter, OSIFI2C_STOP, 0, 0, NULL, 0);
  		if (ret) {
  			dev_err(&adapter->dev, "failure sending STOP
  ");
  			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
  ");
  			return -EREMOTEIO;
  		}
  
  		if (priv->status != STATUS_ADDRESS_ACK) {
  			dev_dbg(&adapter->dev, "status = %d
  ", 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");