/* * driver for the i2c-tiny-usb adapter - 1.0 * http://www.harbaum.org/till/i2c_tiny_usb * * Copyright (C) 2006-2007 Till 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/errno.h>#include <linux/module.h>/* include interfaces to usb layer */#include <linux/usb.h>/* include interface to i2c layer */#include <linux/i2c.h>/* commands via USB, must match command ids in the firmware */#define CMD_ECHO		0#define CMD_GET_FUNC		1#define CMD_SET_DELAY		2#define CMD_GET_STATUS		3#define CMD_I2C_IO		4#define CMD_I2C_IO_BEGIN	(1<<0)#define CMD_I2C_IO_END		(1<<1)/* i2c bit delay, default is 10us -> 100kHz */static int delay = 10;module_param(delay, int, 0);MODULE_PARM_DESC(delay, "bit delay in microseconds, "		 "e.g. 10 for 100kHz (default is 100kHz)");static int usb_read(struct i2c_adapter *adapter, int cmd,		    int value, int index, void *data, int len);static int usb_write(struct i2c_adapter *adapter, int cmd,		     int value, int index, void *data, int len);/* ----- begin of i2c layer ---------------------------------------------- */#define STATUS_IDLE		0#define STATUS_ADDRESS_ACK	1#define STATUS_ADDRESS_NAK	2static int usb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num){	unsigned char status;	struct i2c_msg *pmsg;	int i;	dev_dbg(&adapter->dev, "master xfer %d messages:\n", num);	for (i = 0 ; i < num ; i++) {		int cmd = CMD_I2C_IO;		if (i == 0)			cmd |= CMD_I2C_IO_BEGIN;		if (i == num-1)			cmd |= CMD_I2C_IO_END;		pmsg = &msgs[i];		dev_dbg(&adapter->dev,			"  %d: %s (flags %d) %d bytes to 0x%02x\n",			i, pmsg->flags & I2C_M_RD ? "read" : "write",			pmsg->flags, pmsg->len, pmsg->addr);		/* and directly send the message */		if (pmsg->flags & I2C_M_RD) {			/* read data */			if (usb_read(adapter, cmd,				     pmsg->flags, pmsg->addr,				     pmsg->buf, pmsg->len) != pmsg->len) {				dev_err(&adapter->dev,					"failure reading data\n");				return -EREMOTEIO;			}		} else {			/* write data */			if (usb_write(adapter, cmd,				      pmsg->flags, pmsg->addr,				      pmsg->buf, pmsg->len) != pmsg->len) {				dev_err(&adapter->dev,					"failure writing data\n");				return -EREMOTEIO;			}		}		/* read status */		if (usb_read(adapter, CMD_GET_STATUS, 0, 0, &status, 1) != 1) {			dev_err(&adapter->dev, "failure reading status\n");			return -EREMOTEIO;		}		dev_dbg(&adapter->dev, "  status = %d\n", status);		if (status == STATUS_ADDRESS_NAK)			return -EREMOTEIO;	}	return i;}static u32 usb_func(struct i2c_adapter *adapter){	u32 func;	/* get functionality from adapter */	if (usb_read(adapter, CMD_GET_FUNC, 0, 0, &func, sizeof(func)) !=	    sizeof(func)) {		dev_err(&adapter->dev, "failure reading functionality\n");		return 0;	}	return func;}/* This is the actual algorithm we define */static const struct i2c_algorithm usb_algorithm = {	.master_xfer	= usb_xfer,	.functionality	= usb_func,};/* ----- end of i2c layer ------------------------------------------------ *//* ----- begin of usb layer ---------------------------------------------- *//* The usb i2c interface uses a vid/pid pair donated by *//* Future Technology Devices International Ltd. */static struct usb_device_id i2c_tiny_usb_table [] = {	{ USB_DEVICE(0x0403, 0xc631) },	{ }			/* Terminating entry */};MODULE_DEVICE_TABLE(usb, i2c_tiny_usb_table);/* Structure to hold all of our device specific stuff */struct i2c_tiny_usb {	struct usb_device *usb_dev; /* the usb device for this device */	struct usb_interface *interface; /* the interface for this device */	struct i2c_adapter adapter; /* i2c related things */};static int usb_read(struct i2c_adapter *adapter, int cmd,		    int value, int index, void *data, int len){	struct i2c_tiny_usb *dev = (struct i2c_tiny_usb *)adapter->algo_data;	/* do control transfer */	return usb_control_msg(dev->usb_dev, usb_rcvctrlpipe(dev->usb_dev, 0),			       cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE |			       USB_DIR_IN, value, index, data, len, 2000);}static int usb_write(struct i2c_adapter *adapter, int cmd,		     int value, int index, void *data, int len){	struct i2c_tiny_usb *dev = (struct i2c_tiny_usb *)adapter->algo_data;	/* do control transfer */	return usb_control_msg(dev->usb_dev, usb_sndctrlpipe(dev->usb_dev, 0),			       cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE,			       value, index, data, len, 2000);}static void i2c_tiny_usb_free(struct i2c_tiny_usb *dev){	usb_put_dev(dev->usb_dev);	kfree(dev);}static int i2c_tiny_usb_probe(struct usb_interface *interface,			      const struct usb_device_id *id){	struct i2c_tiny_usb *dev;	int retval = -ENOMEM;	u16 version;	dev_dbg(&interface->dev, "probing usb device\n");	/* allocate memory for our device state and initialize it */	dev = kzalloc(sizeof(*dev), GFP_KERNEL);	if (dev == NULL) {		dev_err(&interface->dev, "Out of memory\n");		goto error;	}	dev->usb_dev = usb_get_dev(interface_to_usbdev(interface));	dev->interface = interface;	/* save our data pointer in this interface device */	usb_set_intfdata(interface, dev);	version = le16_to_cpu(dev->usb_dev->descriptor.bcdDevice);	dev_info(&interface->dev,		 "version %x.%02x found at bus %03d address %03d\n",		 version >> 8, version & 0xff,		 dev->usb_dev->bus->busnum, dev->usb_dev->devnum);	/* setup i2c adapter description */	dev->adapter.owner = THIS_MODULE;	dev->adapter.class = I2C_CLASS_HWMON;	dev->adapter.algo = &usb_algorithm;	dev->adapter.algo_data = dev;	snprintf(dev->adapter.name, sizeof(dev->adapter.name),		 "i2c-tiny-usb at bus %03d device %03d",		 dev->usb_dev->bus->busnum, dev->usb_dev->devnum);	if (usb_write(&dev->adapter, CMD_SET_DELAY,		      cpu_to_le16(delay), 0, NULL, 0) != 0) {		dev_err(&dev->adapter.dev,			"failure setting delay to %dus\n", delay);		retval = -EIO;		goto error;	}	dev->adapter.dev.parent = &dev->interface->dev;	/* and finally attach to i2c layer */	i2c_add_adapter(&dev->adapter);	/* inform user about successful attachment to i2c layer */	dev_info(&dev->adapter.dev, "connected i2c-tiny-usb device\n");	return 0; error:	if (dev)		i2c_tiny_usb_free(dev);	return retval;}static void i2c_tiny_usb_disconnect(struct usb_interface *interface){	struct i2c_tiny_usb *dev = usb_get_intfdata(interface);	i2c_del_adapter(&dev->adapter);	usb_set_intfdata(interface, NULL);	i2c_tiny_usb_free(dev);	dev_dbg(&interface->dev, "disconnected\n");}static struct usb_driver i2c_tiny_usb_driver = {	.name		= "i2c-tiny-usb",	.probe		= i2c_tiny_usb_probe,	.disconnect	= i2c_tiny_usb_disconnect,	.id_table	= i2c_tiny_usb_table,};static int __init usb_i2c_tiny_usb_init(void){	/* register this driver with the USB subsystem */	return usb_register(&i2c_tiny_usb_driver);}static void __exit usb_i2c_tiny_usb_exit(void){	/* deregister this driver with the USB subsystem */	usb_deregister(&i2c_tiny_usb_driver);}module_init(usb_i2c_tiny_usb_init);module_exit(usb_i2c_tiny_usb_exit);/* ----- end of usb layer ------------------------------------------------ */MODULE_AUTHOR("Till Harbaum <Till@Harbaum.org>");MODULE_DESCRIPTION("i2c-tiny-usb driver v1.0");MODULE_LICENSE("GPL");