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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.c212
1 files changed, 121 insertions, 91 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 2597b83a8ae2..351745aec0e1 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -93,8 +93,9 @@ 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;
};
static void ch341_set_termios(struct tty_struct *tty,
@@ -106,12 +107,14 @@ 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,
value, index, NULL, 0, DEFAULT_TIMEOUT);
+ if (r < 0)
+ dev_err(&dev->dev, "failed to send control message: %d\n", r);
return r;
}
@@ -122,18 +125,30 @@ 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,
value, index, buf, bufsize, DEFAULT_TIMEOUT);
- return r;
+ if (r < bufsize) {
+ if (r >= 0) {
+ dev_err(&dev->dev,
+ "short control message received (%d < %u)\n",
+ r, bufsize);
+ r = -EIO;
+ }
+
+ dev_err(&dev->dev, "failed to receive control message: %d\n",
+ r);
+ return r;
+ }
+
+ return 0;
}
-static int ch341_init_set_baudrate(struct usb_device *dev,
- struct ch341_private *priv, unsigned ctrl)
+static int ch341_set_baudrate_lcr(struct usb_device *dev,
+ struct ch341_private *priv, u8 lcr)
{
short a;
int r;
@@ -156,9 +171,19 @@ static int ch341_init_set_baudrate(struct usb_device *dev,
factor = 0x10000 - factor;
a = (factor & 0xff00) | divisor;
- /* 0x9c is "enable SFR_UART Control register and timer" */
- r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT,
- 0x9c | (ctrl << 8), a | 0x80);
+ /*
+ * CH341A buffers data until a full endpoint-size packet (32 bytes)
+ * has been received unless bit 7 is set.
+ */
+ a |= BIT(7);
+
+ r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, a);
+ if (r)
+ return r;
+
+ r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, lcr);
+ if (r)
+ return r;
return r;
}
@@ -170,9 +195,9 @@ static int ch341_set_handshake(struct usb_device *dev, u8 control)
static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
{
+ const unsigned int size = 2;
char *buffer;
int r;
- const unsigned size = 8;
unsigned long flags;
buffer = kmalloc(size, GFP_KERNEL);
@@ -183,14 +208,9 @@ static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
if (r < 0)
goto out;
- /* 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;
- spin_unlock_irqrestore(&priv->lock, flags);
- } else
- r = -EPROTO;
+ spin_lock_irqsave(&priv->lock, flags);
+ priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT;
+ spin_unlock_irqrestore(&priv->lock, flags);
out: kfree(buffer);
return r;
@@ -200,9 +220,9 @@ out: kfree(buffer);
static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
{
+ const unsigned int size = 2;
char *buffer;
int r;
- const unsigned size = 8;
buffer = kmalloc(size, GFP_KERNEL);
if (!buffer)
@@ -218,30 +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_init_set_baudrate(dev, priv, 0);
- if (r < 0)
- goto out;
-
- r = ch341_set_handshake(dev, priv->line_control);
+ r = ch341_set_baudrate_lcr(dev, priv, priv->lcr);
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;
@@ -258,7 +259,11 @@ static int ch341_port_probe(struct usb_serial_port *port)
spin_lock_init(&priv->lock);
priv->baud_rate = DEFAULT_BAUD_RATE;
- priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
+ /*
+ * 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)
@@ -284,7 +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;
}
@@ -297,11 +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)
@@ -314,14 +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)
- goto out;
-
if (tty)
ch341_set_termios(tty, port, NULL);
@@ -330,12 +330,25 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
if (r) {
dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
__func__, r);
- goto out;
+ 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;
+
+ return 0;
-out: return r;
+err_kill_interrupt_urb:
+ usb_kill_urb(port->interrupt_in_urb);
+
+ return r;
}
/* Old_termios contains the original termios settings and
@@ -347,7 +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 */
@@ -356,52 +369,54 @@ static void ch341_set_termios(struct tty_struct *tty,
baud_rate = tty_get_baud_rate(tty);
- priv->baud_rate = baud_rate;
- 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) {
- spin_lock_irqsave(&priv->lock, flags);
- priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
- spin_unlock_irqrestore(&priv->lock, flags);
- r = ch341_init_set_baudrate(port->serial->dev, priv, ctrl);
+ priv->baud_rate = baud_rate;
+
+ 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 = lcr;
}
- } else {
- spin_lock_irqsave(&priv->lock, flags);
- priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
- spin_unlock_irqrestore(&priv->lock, flags);
}
- ch341_set_handshake(port->serial->dev, priv->line_control);
+ spin_lock_irqsave(&priv->lock, flags);
+ if (C_BAUD(tty) == B0)
+ priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
+ else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
+ priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ ch341_set_handshake(port->serial->dev, priv->mcr);
}
static void ch341_break_ctl(struct tty_struct *tty, int break_state)
@@ -457,20 +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);
@@ -485,8 +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)
@@ -539,7 +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) {
@@ -558,8 +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)
@@ -576,14 +591,29 @@ static int ch341_tiocmget(struct tty_struct *tty)
static int ch341_reset_resume(struct usb_serial *serial)
{
- struct ch341_private *priv;
-
- priv = usb_get_serial_port_data(serial->port[0]);
+ struct usb_serial_port *port = serial->port[0];
+ struct ch341_private *priv = usb_get_serial_port_data(port);
+ int ret;
/* reconfigure ch341 serial port after bus-reset */
ch341_configure(serial->dev, priv);
- return 0;
+ if (tty_port_initialized(&port->port)) {
+ ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
+ if (ret) {
+ dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
+ 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);
}
static struct usb_serial_driver ch341_device = {
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.