USB: Driver for CH341 USB-serial adaptor

This patch implements a USB serial port driver for the Winchiphead
CH341 USB-RS232 Converter. This chip also implements an IEEE 1284
parallel port, I2C and SPI, but that is not supported by the driver.

Signed-off-by: Frank A Kingswood <frank@kingswood-consulting.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Frank A Kingswood 2007-08-22 20:48:58 +01:00 committed by Greg Kroah-Hartman
parent 4ac0718e83
commit 6ce7610478
4 changed files with 374 additions and 0 deletions

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@ -428,6 +428,17 @@ Options supported:
See http://www.uuhaus.de/linux/palmconnect.html for up-to-date
information on this driver.
Winchiphead CH341 Driver
This driver is for the Winchiphead CH341 USB-RS232 Converter. This chip
also implements an IEEE 1284 parallel port, I2C and SPI, but that is not
supported by the driver. The protocol was analyzed from the behaviour
of the Windows driver, no datasheet is available at present.
The manufacturer's website: http://www.winchiphead.com/.
For any questions or problems with this driver, please contact
frank@kingswood-consulting.co.uk.
Generic Serial driver
If your device is not one of the above listed devices, compatible with

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@ -92,6 +92,16 @@ config USB_SERIAL_BELKIN
To compile this driver as a module, choose M here: the
module will be called belkin_sa.
config USB_SERIAL_CH341
tristate "USB Winchiphead CH341 Single Port Serial Driver"
depends on USB_SERIAL
help
Say Y here if you want to use a Winchiphead CH341 single port
USB to serial adapter.
To compile this driver as a module, choose M here: the
module will be called ch341.
config USB_SERIAL_WHITEHEAT
tristate "USB ConnectTech WhiteHEAT Serial Driver"
depends on USB_SERIAL

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@ -15,6 +15,7 @@ obj-$(CONFIG_USB_SERIAL_AIRCABLE) += aircable.o
obj-$(CONFIG_USB_SERIAL_AIRPRIME) += airprime.o
obj-$(CONFIG_USB_SERIAL_ARK3116) += ark3116.o
obj-$(CONFIG_USB_SERIAL_BELKIN) += belkin_sa.o
obj-$(CONFIG_USB_SERIAL_CH341) += ch341.o
obj-$(CONFIG_USB_SERIAL_CP2101) += cp2101.o
obj-$(CONFIG_USB_SERIAL_CYBERJACK) += cyberjack.o
obj-$(CONFIG_USB_SERIAL_CYPRESS_M8) += cypress_m8.o

352
drivers/usb/serial/ch341.c Normal file
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@ -0,0 +1,352 @@
/*
* Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
*
* ch341.c implements a serial port driver for the Winchiphead CH341.
*
* The CH341 device can be used to implement an RS232 asynchronous
* serial port, an IEEE-1284 parallel printer port or a memory-like
* interface. In all cases the CH341 supports an I2C interface as well.
* This driver only supports the asynchronous serial interface.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial.h>
#define DEFAULT_BAUD_RATE 2400
#define DEFAULT_TIMEOUT 1000
static int debug;
static struct usb_device_id id_table [] = {
{ USB_DEVICE(0x4348, 0x5523) },
{ },
};
MODULE_DEVICE_TABLE(usb, id_table);
struct ch341_private {
unsigned baud_rate;
u8 dtr;
u8 rts;
};
static int ch341_control_out(struct usb_device *dev, u8 request,
u16 value, u16 index)
{
int r;
dbg("ch341_control_out(%02x,%02x,%04x,%04x)", USB_DIR_OUT|0x40,
(int)request, (int)value, (int)index);
r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
value, index, NULL, 0, DEFAULT_TIMEOUT);
return r;
}
static int ch341_control_in(struct usb_device *dev,
u8 request, u16 value, u16 index,
char *buf, unsigned bufsize)
{
int r;
dbg("ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)", USB_DIR_IN|0x40,
(int)request, (int)value, (int)index, buf, (int)bufsize);
r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
value, index, buf, bufsize, DEFAULT_TIMEOUT);
return r;
}
int ch341_set_baudrate(struct usb_device *dev, struct ch341_private *priv)
{
short a, b;
int r;
dbg("ch341_set_baudrate(%d)", priv->baud_rate);
switch (priv->baud_rate) {
case 2400:
a = 0xd901;
b = 0x0038;
break;
case 4800:
a = 0x6402;
b = 0x001f;
break;
case 9600:
a = 0xb202;
b = 0x0013;
break;
case 19200:
a = 0xd902;
b = 0x000d;
break;
case 38400:
a = 0x6403;
b = 0x000a;
break;
case 115200:
a = 0xcc03;
b = 0x0008;
break;
default:
return -EINVAL;
}
r = ch341_control_out(dev, 0x9a, 0x1312, a);
if (!r)
r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
return r;
}
int ch341_set_handshake(struct usb_device *dev, struct ch341_private *priv)
{
dbg("ch341_set_handshake(%d,%d)", priv->dtr, priv->rts);
return ch341_control_out(dev, 0xa4,
~((priv->dtr?1<<5:0)|(priv->rts?1<<6:0)), 0);
}
int ch341_get_status(struct usb_device *dev)
{
char *buffer;
int r;
const unsigned size = 8;
dbg("ch341_get_status()");
buffer = kmalloc(size, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
if ( r < 0)
goto out;
/* Not having the datasheet for the CH341, we ignore the bytes returned
* from the device. Return error if the device did not respond in time.
*/
r = 0;
out: kfree(buffer);
return r;
}
/* -------------------------------------------------------------------------- */
int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
{
char *buffer;
int r;
const unsigned size = 8;
dbg("ch341_configure()");
buffer = kmalloc(size, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
/* expect two bytes 0x27 0x00 */
r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
if (r < 0)
goto out;
r = ch341_control_out(dev, 0xa1, 0, 0);
if (r < 0)
goto out;
r = ch341_set_baudrate(dev, priv);
if (r < 0)
goto out;
/* expect two bytes 0x56 0x00 */
r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
if (r < 0)
goto out;
r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
if (r < 0)
goto out;
/* expect 0xff 0xee */
r = ch341_get_status(dev);
if (r < 0)
goto out;
r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
if (r < 0)
goto out;
r = ch341_set_baudrate(dev, priv);
if (r < 0)
goto out;
r = ch341_set_handshake(dev, priv);
if (r < 0)
goto out;
/* expect 0x9f 0xee */
r = ch341_get_status(dev);
out: kfree(buffer);
return r;
}
/* allocate private data */
static int ch341_attach(struct usb_serial *serial)
{
struct ch341_private *priv;
int r;
dbg("ch341_attach()");
/* private data */
priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->baud_rate = DEFAULT_BAUD_RATE;
priv->dtr = 1;
priv->rts = 1;
r = ch341_configure(serial->dev, priv);
if (r < 0)
goto error;
usb_set_serial_port_data(serial->port[0], priv);
return 0;
error: kfree(priv);
return r;
}
/* open this device, set default parameters */
static int ch341_open(struct usb_serial_port *port, struct file *filp)
{
struct usb_serial *serial = port->serial;
struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
int r;
dbg("ch341_open()");
priv->baud_rate = DEFAULT_BAUD_RATE;
priv->dtr = 1;
priv->rts = 1;
r = ch341_configure(serial->dev, priv);
if (r)
goto out;
r = ch341_set_handshake(serial->dev, priv);
if (r)
goto out;
r = ch341_set_baudrate(serial->dev, priv);
if (r)
goto out;
r = usb_serial_generic_open(port, filp);
out: return r;
}
/* Old_termios contains the original termios settings and
* tty->termios contains the new setting to be used.
*/
static void ch341_set_termios(struct usb_serial_port *port,
struct ktermios *old_termios)
{
struct ch341_private *priv = usb_get_serial_port_data(port);
struct tty_struct *tty = port->tty;
unsigned baud_rate;
dbg("ch341_set_termios()");
if (!tty || !tty->termios)
return;
baud_rate = tty_get_baud_rate(tty);
switch (baud_rate) {
case 2400:
case 4800:
case 9600:
case 19200:
case 38400:
case 115200:
priv->baud_rate = baud_rate;
break;
default:
dbg("Rate %d not supported, using %d",
baud_rate, DEFAULT_BAUD_RATE);
priv->baud_rate = DEFAULT_BAUD_RATE;
}
ch341_set_baudrate(port->serial->dev, priv);
/* Unimplemented:
* (cflag & CSIZE) : data bits [5, 8]
* (cflag & PARENB) : parity {NONE, EVEN, ODD}
* (cflag & CSTOPB) : stop bits [1, 2]
*/
}
static struct usb_driver ch341_driver = {
.name = "ch341",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.id_table = id_table,
.no_dynamic_id = 1,
};
static struct usb_serial_driver ch341_device = {
.driver = {
.owner = THIS_MODULE,
.name = "ch341-uart",
},
.id_table = id_table,
.usb_driver = &ch341_driver,
.num_interrupt_in = NUM_DONT_CARE,
.num_bulk_in = 1,
.num_bulk_out = 1,
.num_ports = 1,
.open = ch341_open,
.set_termios = ch341_set_termios,
.attach = ch341_attach,
};
static int __init ch341_init(void)
{
int retval;
retval = usb_serial_register(&ch341_device);
if (retval)
return retval;
retval = usb_register(&ch341_driver);
if (retval)
usb_serial_deregister(&ch341_device);
return retval;
}
static void __exit ch341_exit(void)
{
usb_deregister(&ch341_driver);
usb_serial_deregister(&ch341_device);
}
module_init(ch341_init);
module_exit(ch341_exit);
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
/* EOF ch341.c */