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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.c287
1 files changed, 177 insertions, 110 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index f139488d0816..351745aec0e1 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -61,13 +61,26 @@
* the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
*/
+#define CH341_REQ_READ_VERSION 0x5F
#define CH341_REQ_WRITE_REG 0x9A
#define CH341_REQ_READ_REG 0x95
-#define CH341_REG_BREAK1 0x05
-#define CH341_REG_BREAK2 0x18
-#define CH341_NBREAK_BITS_REG1 0x01
-#define CH341_NBREAK_BITS_REG2 0x40
-
+#define CH341_REQ_SERIAL_INIT 0xA1
+#define CH341_REQ_MODEM_CTRL 0xA4
+
+#define CH341_REG_BREAK 0x05
+#define CH341_REG_LCR 0x18
+#define CH341_NBREAK_BITS 0x01
+
+#define CH341_LCR_ENABLE_RX 0x80
+#define CH341_LCR_ENABLE_TX 0x40
+#define CH341_LCR_MARK_SPACE 0x20
+#define CH341_LCR_PAR_EVEN 0x10
+#define CH341_LCR_ENABLE_PAR 0x08
+#define CH341_LCR_STOP_BITS_2 0x04
+#define CH341_LCR_CS8 0x03
+#define CH341_LCR_CS7 0x02
+#define CH341_LCR_CS6 0x01
+#define CH341_LCR_CS5 0x00
static const struct usb_device_id id_table[] = {
{ USB_DEVICE(0x4348, 0x5523) },
@@ -80,8 +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,
@@ -93,12 +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;
}
@@ -109,20 +125,32 @@ 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_set_baudrate(struct usb_device *dev,
- struct ch341_private *priv)
+static int ch341_set_baudrate_lcr(struct usb_device *dev,
+ struct ch341_private *priv, u8 lcr)
{
- short a, b;
+ short a;
int r;
unsigned long factor;
short divisor;
@@ -142,43 +170,47 @@ static int ch341_set_baudrate(struct usb_device *dev,
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);
+ /*
+ * 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;
}
static int ch341_set_handshake(struct usb_device *dev, u8 control)
{
- return ch341_control_out(dev, 0xa4, ~control, 0);
+ return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
}
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);
if (!buffer)
return -ENOMEM;
- r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
+ r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
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;
@@ -188,55 +220,29 @@ 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)
return -ENOMEM;
/* expect two bytes 0x27 0x00 */
- r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
+ r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
if (r < 0)
goto out;
+ dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);
- r = ch341_control_out(dev, 0xa1, 0, 0);
+ r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
if (r < 0)
goto out;
- r = ch341_set_baudrate(dev, priv);
+ r = ch341_set_baudrate_lcr(dev, priv, priv->lcr);
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, priv);
- 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->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;
@@ -253,7 +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)
@@ -279,7 +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;
}
@@ -292,11 +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)
@@ -309,14 +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);
@@ -325,12 +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;
+
+err_kill_interrupt_urb:
+ usb_kill_urb(port->interrupt_in_urb);
-out: return r;
+ return r;
}
/* Old_termios contains the original termios settings and
@@ -342,35 +360,69 @@ 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;
+ u8 lcr;
+ int r;
+
+ /* redundant changes may cause the chip to lose bytes */
+ if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
+ return;
baud_rate = tty_get_baud_rate(tty);
- priv->baud_rate = baud_rate;
+ lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
+
+ switch (C_CSIZE(tty)) {
+ case CS5:
+ lcr |= CH341_LCR_CS5;
+ break;
+ case CS6:
+ lcr |= CH341_LCR_CS6;
+ break;
+ case CS7:
+ lcr |= CH341_LCR_CS7;
+ break;
+ case CS8:
+ lcr |= CH341_LCR_CS8;
+ break;
+ }
+
+ if (C_PARENB(tty)) {
+ lcr |= CH341_LCR_ENABLE_PAR;
+ if (C_PARODD(tty) == 0)
+ lcr |= CH341_LCR_PAR_EVEN;
+ if (C_CMSPAR(tty))
+ lcr |= CH341_LCR_MARK_SPACE;
+ }
+
+ if (C_CSTOPB(tty))
+ 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);
- 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);
+ 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;
+ }
}
- 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);
- /* Unimplemented:
- * (cflag & CSIZE) : data bits [5, 8]
- * (cflag & PARENB) : parity {NONE, EVEN, ODD}
- * (cflag & CSTOPB) : stop bits [1, 2]
- */
+ ch341_set_handshake(port->serial->dev, priv->mcr);
}
static void ch341_break_ctl(struct tty_struct *tty, int break_state)
{
const uint16_t ch341_break_reg =
- ((uint16_t) CH341_REG_BREAK2 << 8) | CH341_REG_BREAK1;
+ ((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK;
struct usb_serial_port *port = tty->driver_data;
int r;
uint16_t reg_contents;
@@ -391,12 +443,12 @@ static void ch341_break_ctl(struct tty_struct *tty, int break_state)
__func__, break_reg[0], break_reg[1]);
if (break_state != 0) {
dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
- break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
- break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
+ break_reg[0] &= ~CH341_NBREAK_BITS;
+ break_reg[1] &= ~CH341_LCR_ENABLE_TX;
} else {
dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
- break_reg[0] |= CH341_NBREAK_BITS_REG1;
- break_reg[1] |= CH341_NBREAK_BITS_REG2;
+ break_reg[0] |= CH341_NBREAK_BITS;
+ break_reg[1] |= CH341_LCR_ENABLE_TX;
}
dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
__func__, break_reg[0], break_reg[1]);
@@ -420,20 +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);
@@ -448,8 +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)
@@ -502,7 +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) {
@@ -521,8 +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)
@@ -539,14 +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 = {
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-08 19:33:50 +0000