2007-05-01 21:26:35 +00:00
|
|
|
/*
|
|
|
|
* 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>
|
2010-02-05 16:48:13 +00:00
|
|
|
#include <linux/types.h>
|
2007-05-01 21:26:35 +00:00
|
|
|
|
|
|
|
/* 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 */
|
2010-02-05 16:48:13 +00:00
|
|
|
static unsigned short delay = 10;
|
|
|
|
module_param(delay, ushort, 0);
|
2007-05-01 21:26:35 +00:00
|
|
|
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 2
|
|
|
|
|
|
|
|
static 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)
|
|
|
|
{
|
2010-02-05 16:48:13 +00:00
|
|
|
__le32 func;
|
2007-05-01 21:26:35 +00:00
|
|
|
|
|
|
|
/* 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;
|
|
|
|
}
|
|
|
|
|
2010-02-05 16:48:13 +00:00
|
|
|
return le32_to_cpu(func);
|
2007-05-01 21:26:35 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/* 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 ---------------------------------------------- */
|
|
|
|
|
2008-04-11 10:07:05 +00:00
|
|
|
/*
|
|
|
|
* Initially the usb i2c interface uses a vid/pid pair donated by
|
|
|
|
* Future Technology Devices International Ltd., later a pair was
|
|
|
|
* bought from EZPrototypes
|
|
|
|
*/
|
2007-05-01 21:26:35 +00:00
|
|
|
static struct usb_device_id i2c_tiny_usb_table [] = {
|
2008-04-11 10:07:05 +00:00
|
|
|
{ USB_DEVICE(0x0403, 0xc631) }, /* FTDI */
|
|
|
|
{ USB_DEVICE(0x1c40, 0x0534) }, /* EZPrototypes */
|
|
|
|
{ } /* Terminating entry */
|
2007-05-01 21:26:35 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
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;
|
2007-05-22 17:49:16 +00:00
|
|
|
snprintf(dev->adapter.name, sizeof(dev->adapter.name),
|
2007-05-01 21:26:35 +00:00
|
|
|
"i2c-tiny-usb at bus %03d device %03d",
|
|
|
|
dev->usb_dev->bus->busnum, dev->usb_dev->devnum);
|
|
|
|
|
2010-02-05 16:48:13 +00:00
|
|
|
if (usb_write(&dev->adapter, CMD_SET_DELAY, delay, 0, NULL, 0) != 0) {
|
2007-05-01 21:26:35 +00:00
|
|
|
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");
|