Skip to content

L
linux
Commit 664d5df9 authored by Werner Cornelius's avatar Werner Cornelius Committed by Greg Kroah-Hartman
5 Browse files
Options

USB: usb-serial ch341: support for DTR/RTS/CTS 

Fixup of Werner Cornelius patch to the ch341 USB-serial driver, which adds:
- support all baudrates, not just a hard-coded set
- support for controlling DTR, RTS and CTS

Features still missing:
- character length other than 8 bits
- parity settings
- break control

I adapted his patch for the new usb_serial API introduced in 2.6.25-git8 by
Alan Cox on 22 July 2008. Non-compliance to the new API was a reason for
refusing a similar patch from Tollef Fog Heen.

Usage example by Tollef Fog Heen :
        TEMPer USB thermometer <http://err.no/src/TEMPer.c>
Signed-off-by: default avatarWerner Cornelius <Werner.Cornelius@cornelius-consult.de>
Signed-off-by: default avatarBoris Hajduk <boris@hajduk.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent bcbbbfc1
Hide whitespace changes
Inline Side-by-side
Showing with 302 additions and 72 deletions
drivers/usb/serial/ch341.c
View file @ 664d5df9
/*
* Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
* Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
* Copyright 2009, Boris Hajduk <boris@hajduk.org>
*
* ch341.c implements a serial port driver for the Winchiphead CH341.
*
......@@ -21,9 +23,39 @@
#include <linux/usb/serial.h>
#include <linux/serial.h>
#define DEFAULT_BAUD_RATE 2400
#define DEFAULT_BAUD_RATE 9600
#define DEFAULT_TIMEOUT 1000
/* flags for IO-Bits */
#define CH341_BIT_RTS (1 << 6)
#define CH341_BIT_DTR (1 << 5)
/******************************/
/* interrupt pipe definitions */
/******************************/
/* always 4 interrupt bytes */
/* first irq byte normally 0x08 */
/* second irq byte base 0x7d + below */
/* third irq byte base 0x94 + below */
/* fourth irq byte normally 0xee */
/* second interrupt byte */
#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
/* status returned in third interrupt answer byte, inverted in data
from irq */
#define CH341_BIT_CTS 0x01
#define CH341_BIT_DSR 0x02
#define CH341_BIT_RI 0x04
#define CH341_BIT_DCD 0x08
#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
/*******************************/
/* baudrate calculation factor */
/*******************************/
#define CH341_BAUDBASE_FACTOR 1532620800
#define CH341_BAUDBASE_DIVMAX 3
static int debug;
static struct usb_device_id id_table [] = {
......@@ -34,9 +66,12 @@ static struct usb_device_id id_table [] = {
MODULE_DEVICE_TABLE(usb, id_table);
struct ch341_private {
unsigned baud_rate;
u8 dtr;
u8 rts;
spinlock_t lock; /* access lock */
wait_queue_head_t delta_msr_wait; /* wait queue for modem status */
unsigned baud_rate; /* set baud rate */
u8 line_control; /* set line control value RTS/DTR */
u8 line_status; /* active status of modem control inputs */
u8 multi_status_change; /* status changed multiple since last call */
};
static int ch341_control_out(struct usb_device *dev, u8 request,
......@@ -72,37 +107,28 @@ static int ch341_set_baudrate(struct usb_device *dev,
{
short a, b;
int r;
unsigned long factor;
short divisor;
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:
if (!priv->baud_rate)
return -EINVAL;
factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
divisor = CH341_BAUDBASE_DIVMAX;
while ((factor > 0xfff0) && divisor) {
factor >>= 3;
divisor--;
}
if (factor > 0xfff0)
return -EINVAL;
factor = 0x10000 - factor;
a = (factor & 0xff00) | divisor;
b = factor & 0xff;
r = ch341_control_out(dev, 0x9a, 0x1312, a);
if (!r)
r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
......@@ -110,19 +136,18 @@ static int ch341_set_baudrate(struct usb_device *dev,
return r;
}
static int ch341_set_handshake(struct usb_device *dev,
struct ch341_private *priv)
static int ch341_set_handshake(struct usb_device *dev, u8 control)
{
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);
dbg("ch341_set_handshake(0x%02x)", control);
return ch341_control_out(dev, 0xa4, ~control, 0);
}
static int ch341_get_status(struct usb_device *dev)
static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
{
char *buffer;
int r;
const unsigned size = 8;
unsigned long flags;
dbg("ch341_get_status()");
......@@ -134,10 +159,15 @@ static int ch341_get_status(struct usb_device *dev)
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;
/* setup the private status if available */
if (r == 2) {
r = 0;
spin_lock_irqsave(&priv->lock, flags);
priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
priv->multi_status_change = 0;
spin_unlock_irqrestore(&priv->lock, flags);
} else
r = -EPROTO;
out: kfree(buffer);
return r;
......@@ -180,7 +210,7 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
goto out;
/* expect 0xff 0xee */
r = ch341_get_status(dev);
r = ch341_get_status(dev, priv);
if (r < 0)
goto out;
......@@ -192,12 +222,12 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
if (r < 0)
goto out;
r = ch341_set_handshake(dev, priv);
r = ch341_set_handshake(dev, priv->line_control);
if (r < 0)
goto out;
/* expect 0x9f 0xee */
r = ch341_get_status(dev);
r = ch341_get_status(dev, priv);
out: kfree(buffer);
return r;
......@@ -216,9 +246,10 @@ static int ch341_attach(struct usb_serial *serial)
if (!priv)
return -ENOMEM;
spin_lock_init(&priv->lock);
init_waitqueue_head(&priv->delta_msr_wait);
priv->baud_rate = DEFAULT_BAUD_RATE;
priv->dtr = 1;
priv->rts = 1;
priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
r = ch341_configure(serial->dev, priv);
if (r < 0)
......@@ -231,6 +262,35 @@ error: kfree(priv);
return r;
}
static void ch341_close(struct tty_struct *tty, struct usb_serial_port *port,
struct file *filp)
{
struct ch341_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
unsigned int c_cflag;
dbg("%s - port %d", __func__, port->number);
/* shutdown our urbs */
dbg("%s - shutting down urbs", __func__);
usb_kill_urb(port->write_urb);
usb_kill_urb(port->read_urb);
usb_kill_urb(port->interrupt_in_urb);
if (tty) {
c_cflag = tty->termios->c_cflag;
if (c_cflag & HUPCL) {
/* drop DTR and RTS */
spin_lock_irqsave(&priv->lock, flags);
priv->line_control = 0;
spin_unlock_irqrestore(&priv->lock, flags);
ch341_set_handshake(port->serial->dev, 0);
}
}
wake_up_interruptible(&priv->delta_msr_wait);
}
/* open this device, set default parameters */
static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
struct file *filp)
......@@ -242,14 +302,13 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
dbg("ch341_open()");
priv->baud_rate = DEFAULT_BAUD_RATE;
priv->dtr = 1;
priv->rts = 1;
priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
r = ch341_configure(serial->dev, priv);
if (r)
goto out;
r = ch341_set_handshake(serial->dev, priv);
r = ch341_set_handshake(serial->dev, priv->line_control);
if (r)
goto out;
......@@ -257,6 +316,16 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
if (r)
goto out;
dbg("%s - submitting interrupt urb", __func__);
port->interrupt_in_urb->dev = serial->dev;
r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (r) {
dev_err(&port->dev, "%s - failed submitting interrupt urb,"
" error %d\n", __func__, r);
ch341_close(tty, port, NULL);
return -EPROTO;
}
r = usb_serial_generic_open(tty, port, filp);
out: return r;
......@@ -270,38 +339,194 @@ static void ch341_set_termios(struct tty_struct *tty,
{
struct ch341_private *priv = usb_get_serial_port_data(port);
unsigned baud_rate;
unsigned long flags;
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;
priv->baud_rate = baud_rate;
if (baud_rate) {
spin_lock_irqsave(&priv->lock, flags);
priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
spin_unlock_irqrestore(&priv->lock, flags);
ch341_set_baudrate(port->serial->dev, priv);
} else {
spin_lock_irqsave(&priv->lock, flags);
priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
spin_unlock_irqrestore(&priv->lock, flags);
}
ch341_set_baudrate(port->serial->dev, priv);
ch341_set_handshake(port->serial->dev, priv->line_control);
/* Unimplemented:
* (cflag & CSIZE) : data bits [5, 8]
* (cflag & PARENB) : parity {NONE, EVEN, ODD}
* (cflag & CSTOPB) : stop bits [1, 2]
*/
}
static int ch341_tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear)
{
struct usb_serial_port *port = tty->driver_data;
struct ch341_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
u8 control;
spin_lock_irqsave(&priv->lock, flags);
if (set & TIOCM_RTS)
priv->line_control |= CH341_BIT_RTS;
if (set & TIOCM_DTR)
priv->line_control |= CH341_BIT_DTR;
if (clear & TIOCM_RTS)
priv->line_control &= ~CH341_BIT_RTS;
if (clear & TIOCM_DTR)
priv->line_control &= ~CH341_BIT_DTR;
control = priv->line_control;
spin_unlock_irqrestore(&priv->lock, flags);
return ch341_set_handshake(port->serial->dev, control);
}
static void ch341_read_int_callback(struct urb *urb)
{
struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
unsigned char *data = urb->transfer_buffer;
unsigned int actual_length = urb->actual_length;
int status;
dbg("%s (%d)", __func__, port->number);
switch (urb->status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dbg("%s - urb shutting down with status: %d", __func__,
urb->status);
return;
default:
dbg("%s - nonzero urb status received: %d", __func__,
urb->status);
goto exit;
}
usb_serial_debug_data(debug, &port->dev, __func__,
urb->actual_length, urb->transfer_buffer);
if (actual_length >= 4) {
struct ch341_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
if ((data[1] & CH341_MULT_STAT))
priv->multi_status_change = 1;
spin_unlock_irqrestore(&priv->lock, flags);
wake_up_interruptible(&priv->delta_msr_wait);
}
exit:
status = usb_submit_urb(urb, GFP_ATOMIC);
if (status)
dev_err(&urb->dev->dev,
"%s - usb_submit_urb failed with result %d\n",
__func__, status);
}
static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
{
struct ch341_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
u8 prevstatus;
u8 status;
u8 changed;
u8 multi_change = 0;
spin_lock_irqsave(&priv->lock, flags);
prevstatus = priv->line_status;
priv->multi_status_change = 0;
spin_unlock_irqrestore(&priv->lock, flags);
while (!multi_change) {
interruptible_sleep_on(&priv->delta_msr_wait);
/* see if a signal did it */
if (signal_pending(current))
return -ERESTARTSYS;
spin_lock_irqsave(&priv->lock, flags);
status = priv->line_status;
multi_change = priv->multi_status_change;
spin_unlock_irqrestore(&priv->lock, flags);
changed = prevstatus ^ status;
if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||
((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||
((arg & TIOCM_CD) && (changed & CH341_BIT_DCD)) ||
((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
return 0;
}
prevstatus = status;
}
return 0;
}
/*static int ch341_ioctl(struct usb_serial_port *port, struct file *file,*/
static int ch341_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
switch (cmd) {
case TIOCMIWAIT:
dbg("%s (%d) TIOCMIWAIT", __func__, port->number);
return wait_modem_info(port, arg);
default:
dbg("%s not supported = 0x%04x", __func__, cmd);
break;
}
return -ENOIOCTLCMD;
}
static int ch341_tiocmget(struct tty_struct *tty, struct file *file)
{
struct usb_serial_port *port = tty->driver_data;
struct ch341_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
u8 mcr;
u8 status;
unsigned int result;
dbg("%s (%d)", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
mcr = priv->line_control;
status = priv->line_status;
spin_unlock_irqrestore(&priv->lock, flags);
result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
| ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
| ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
| ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
| ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
dbg("%s - result = %x", __func__, result);
/* Copy back the old hardware settings */
tty_termios_copy_hw(tty->termios, old_termios);
/* And re-encode with the new baud */
tty_encode_baud_rate(tty, baud_rate, baud_rate);
return result;
}
static struct usb_driver ch341_driver = {
......@@ -317,12 +542,17 @@ static struct usb_serial_driver ch341_device = {
.owner = THIS_MODULE,
.name = "ch341-uart",
},
.id_table = id_table,
.usb_driver = &ch341_driver,
.num_ports = 1,
.open = ch341_open,
.set_termios = ch341_set_termios,
.attach = ch341_attach,
.id_table = id_table,
.usb_driver = &ch341_driver,
.num_ports = 1,
.open = ch341_open,
.close = ch341_close,
.ioctl = ch341_ioctl,
.set_termios = ch341_set_termios,
.tiocmget = ch341_tiocmget,
.tiocmset = ch341_tiocmset,
.read_int_callback = ch341_read_int_callback,
.attach = ch341_attach,
};
static int __init ch341_init(void)
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7