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path: root/drivers/usb/serial/ch341.c
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Diffstat (limited to 'drivers/usb/serial/ch341.c')
-rw-r--r--drivers/usb/serial/ch341.c118
1 files changed, 55 insertions, 63 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 95aa5233726c..351745aec0e1 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -93,8 +93,8 @@ MODULE_DEVICE_TABLE(usb, id_table);
struct ch341_private {
spinlock_t lock; /* access lock */
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 mcr;
+ u8 msr;
u8 lcr;
};
@@ -107,8 +107,8 @@ static int ch341_control_out(struct usb_device *dev, u8 request,
{
int r;
- dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
- USB_DIR_OUT|0x40, (int)request, (int)value, (int)index);
+ dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__,
+ request, value, index);
r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
@@ -125,9 +125,8 @@ static int ch341_control_in(struct usb_device *dev,
{
int r;
- dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
- USB_DIR_IN|0x40, (int)request, (int)value, (int)index, buf,
- (int)bufsize);
+ dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__,
+ request, value, index, bufsize);
r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
@@ -210,7 +209,7 @@ static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
goto out;
spin_lock_irqsave(&priv->lock, flags);
- priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
+ priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT;
spin_unlock_irqrestore(&priv->lock, flags);
out: kfree(buffer);
@@ -239,30 +238,11 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
if (r < 0)
goto out;
- /* expect two bytes 0x56 0x00 */
- r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x2518, 0, buffer, size);
- if (r < 0)
- goto out;
-
- r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, 0x0050);
- if (r < 0)
- goto out;
-
- /* expect 0xff 0xee */
- r = ch341_get_status(dev, priv);
- if (r < 0)
- goto out;
-
r = ch341_set_baudrate_lcr(dev, priv, priv->lcr);
if (r < 0)
goto out;
- r = ch341_set_handshake(dev, priv->line_control);
- if (r < 0)
- goto out;
-
- /* expect 0x9f 0xee */
- r = ch341_get_status(dev, priv);
+ r = ch341_set_handshake(dev, priv->mcr);
out: kfree(buffer);
return r;
@@ -279,6 +259,11 @@ static int ch341_port_probe(struct usb_serial_port *port)
spin_lock_init(&priv->lock);
priv->baud_rate = DEFAULT_BAUD_RATE;
+ /*
+ * Some CH340 devices appear unable to change the initial LCR
+ * settings, so set a sane 8N1 default.
+ */
+ priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;
r = ch341_configure(port->serial->dev, priv);
if (r < 0)
@@ -304,7 +289,7 @@ static int ch341_port_remove(struct usb_serial_port *port)
static int ch341_carrier_raised(struct usb_serial_port *port)
{
struct ch341_private *priv = usb_get_serial_port_data(port);
- if (priv->line_status & CH341_BIT_DCD)
+ if (priv->msr & CH341_BIT_DCD)
return 1;
return 0;
}
@@ -317,11 +302,11 @@ static void ch341_dtr_rts(struct usb_serial_port *port, int on)
/* drop DTR and RTS */
spin_lock_irqsave(&priv->lock, flags);
if (on)
- priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
+ priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR;
else
- priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
+ priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
spin_unlock_irqrestore(&priv->lock, flags);
- ch341_set_handshake(port->serial->dev, priv->line_control);
+ ch341_set_handshake(port->serial->dev, priv->mcr);
}
static void ch341_close(struct usb_serial_port *port)
@@ -334,14 +319,9 @@ static void ch341_close(struct usb_serial_port *port)
/* open this device, set default parameters */
static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
{
- struct usb_serial *serial = port->serial;
struct ch341_private *priv = usb_get_serial_port_data(port);
int r;
- r = ch341_configure(serial->dev, priv);
- if (r)
- return r;
-
if (tty)
ch341_set_termios(tty, port, NULL);
@@ -353,6 +333,12 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
return r;
}
+ r = ch341_get_status(port->serial->dev, priv);
+ if (r < 0) {
+ dev_err(&port->dev, "failed to read modem status: %d\n", r);
+ goto err_kill_interrupt_urb;
+ }
+
r = usb_serial_generic_open(tty, port);
if (r)
goto err_kill_interrupt_urb;
@@ -374,7 +360,7 @@ 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;
- unsigned char ctrl;
+ u8 lcr;
int r;
/* redundant changes may cause the chip to lose bytes */
@@ -383,54 +369,54 @@ static void ch341_set_termios(struct tty_struct *tty,
baud_rate = tty_get_baud_rate(tty);
- ctrl = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
+ lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
switch (C_CSIZE(tty)) {
case CS5:
- ctrl |= CH341_LCR_CS5;
+ lcr |= CH341_LCR_CS5;
break;
case CS6:
- ctrl |= CH341_LCR_CS6;
+ lcr |= CH341_LCR_CS6;
break;
case CS7:
- ctrl |= CH341_LCR_CS7;
+ lcr |= CH341_LCR_CS7;
break;
case CS8:
- ctrl |= CH341_LCR_CS8;
+ lcr |= CH341_LCR_CS8;
break;
}
if (C_PARENB(tty)) {
- ctrl |= CH341_LCR_ENABLE_PAR;
+ lcr |= CH341_LCR_ENABLE_PAR;
if (C_PARODD(tty) == 0)
- ctrl |= CH341_LCR_PAR_EVEN;
+ lcr |= CH341_LCR_PAR_EVEN;
if (C_CMSPAR(tty))
- ctrl |= CH341_LCR_MARK_SPACE;
+ lcr |= CH341_LCR_MARK_SPACE;
}
if (C_CSTOPB(tty))
- ctrl |= CH341_LCR_STOP_BITS_2;
+ lcr |= CH341_LCR_STOP_BITS_2;
if (baud_rate) {
priv->baud_rate = baud_rate;
- r = ch341_set_baudrate_lcr(port->serial->dev, priv, ctrl);
+ r = ch341_set_baudrate_lcr(port->serial->dev, priv, lcr);
if (r < 0 && old_termios) {
priv->baud_rate = tty_termios_baud_rate(old_termios);
tty_termios_copy_hw(&tty->termios, old_termios);
} else if (r == 0) {
- priv->lcr = ctrl;
+ priv->lcr = lcr;
}
}
spin_lock_irqsave(&priv->lock, flags);
if (C_BAUD(tty) == B0)
- priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
+ priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
- priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
+ priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS);
spin_unlock_irqrestore(&priv->lock, flags);
- ch341_set_handshake(port->serial->dev, priv->line_control);
+ ch341_set_handshake(port->serial->dev, priv->mcr);
}
static void ch341_break_ctl(struct tty_struct *tty, int break_state)
@@ -486,20 +472,20 @@ static int ch341_tiocmset(struct tty_struct *tty,
spin_lock_irqsave(&priv->lock, flags);
if (set & TIOCM_RTS)
- priv->line_control |= CH341_BIT_RTS;
+ priv->mcr |= CH341_BIT_RTS;
if (set & TIOCM_DTR)
- priv->line_control |= CH341_BIT_DTR;
+ priv->mcr |= CH341_BIT_DTR;
if (clear & TIOCM_RTS)
- priv->line_control &= ~CH341_BIT_RTS;
+ priv->mcr &= ~CH341_BIT_RTS;
if (clear & TIOCM_DTR)
- priv->line_control &= ~CH341_BIT_DTR;
- control = priv->line_control;
+ priv->mcr &= ~CH341_BIT_DTR;
+ control = priv->mcr;
spin_unlock_irqrestore(&priv->lock, flags);
return ch341_set_handshake(port->serial->dev, control);
}
-static void ch341_update_line_status(struct usb_serial_port *port,
+static void ch341_update_status(struct usb_serial_port *port,
unsigned char *data, size_t len)
{
struct ch341_private *priv = usb_get_serial_port_data(port);
@@ -514,8 +500,8 @@ static void ch341_update_line_status(struct usb_serial_port *port,
status = ~data[2] & CH341_BITS_MODEM_STAT;
spin_lock_irqsave(&priv->lock, flags);
- delta = status ^ priv->line_status;
- priv->line_status = status;
+ delta = status ^ priv->msr;
+ priv->msr = status;
spin_unlock_irqrestore(&priv->lock, flags);
if (data[1] & CH341_MULT_STAT)
@@ -568,7 +554,7 @@ static void ch341_read_int_callback(struct urb *urb)
}
usb_serial_debug_data(&port->dev, __func__, len, data);
- ch341_update_line_status(port, data, len);
+ ch341_update_status(port, data, len);
exit:
status = usb_submit_urb(urb, GFP_ATOMIC);
if (status) {
@@ -587,8 +573,8 @@ static int ch341_tiocmget(struct tty_struct *tty)
unsigned int result;
spin_lock_irqsave(&priv->lock, flags);
- mcr = priv->line_control;
- status = priv->line_status;
+ mcr = priv->mcr;
+ status = priv->msr;
spin_unlock_irqrestore(&priv->lock, flags);
result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
@@ -619,6 +605,12 @@ static int ch341_reset_resume(struct usb_serial *serial)
ret);
return ret;
}
+
+ ret = ch341_get_status(port->serial->dev, priv);
+ if (ret < 0) {
+ dev_err(&port->dev, "failed to read modem status: %d\n",
+ ret);
+ }
}
return usb_serial_generic_resume(serial);
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