From: Charles Yeh <charlesyeh522@gmail.com>
To: gregkh@linuxfoundation.org, johan@kernel.org, linux-usb@vger.kernel.org
Cc: charles-yeh@prolific.com.tw, Charles Yeh <charlesyeh522@gmail.com>
Subject: [PATCH v3] USB: serial: pl2303: add support for PL256X multi-port devices
Date: Tue, 21 Jul 2026 19:24:40 +0800 [thread overview]
Message-ID: <20260721112440.1816-1-charlesyeh522@gmail.com> (raw)
Prolific PL256X devices are multi-port USB-to-UART controllers,
including the PL2533, PL2543 and PL2565 variants.
These devices use vendor requests that differ from those used by the
existing TYPE_HX and TYPE_HXN devices. They also require a separate UART
reset request and use a port-specific register for configuring flow
control.
Add a new TYPE_MP device type and select the appropriate vendor requests,
reset operation and flow-control register for PL256X devices. Store the
USB interface number so that requests can be directed to the corresponding
UART port.
Detect the supported PL256X variants using bcdDevice before issuing any
legacy vendor requests, as PL256X devices do not accept those requests.
PL256X devices support baud rates up to 24 Mbps and do not use divisor
encoding.
Signed-off-by: Charles Yeh <charlesyeh522@gmail.com>
---
v3:
* update the patch subject to describe PL256X multi-port support
* add device variant comments to the bcdDevice table
* use lowercase hexadecimal constants
* simplify pl256x_uart_reset() by removing unnecessary arguments
* improve the UART reset error message
* fix continuation-line indentation
* preserve reverse Christmas tree declaration order
* add a default error case for unsupported interface numbers
* remove the redundant flow-control configuration from startup
v2:
* remove unused variable 'dev' in pl2303_update_reg
---
drivers/usb/serial/pl2303.c | 108 +++++++++++++++++++++++++++++++++---
drivers/usb/serial/pl2303.h | 2 +-
2 files changed, 102 insertions(+), 8 deletions(-)
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 50dc838e8115..11d504416e96 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -54,6 +54,7 @@ static const struct usb_device_id id_table[] = {
{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GL) },
{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GE) },
{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GS) },
+ { USB_DEVICE(PL2303_VENDOR_ID, PL256X_PRODUCT_ID_4P) },
{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID),
@@ -144,10 +145,15 @@ MODULE_DEVICE_TABLE(usb, id_table);
#define VENDOR_WRITE_REQUEST_TYPE 0x40
#define VENDOR_WRITE_REQUEST 0x01
#define VENDOR_WRITE_NREQUEST 0x80
+#define VENDOR_WRITE_MPREQUEST 0x80
#define VENDOR_READ_REQUEST_TYPE 0xc0
#define VENDOR_READ_REQUEST 0x01
#define VENDOR_READ_NREQUEST 0x81
+#define VENDOR_READ_MPREQUEST 0x80
+
+#define PL256X_RESET_REQUEST_TYPE 0x40
+#define PL256X_RESET_REQUEST 0x96
#define UART_STATE_INDEX 8
#define UART_STATE_MSR_MASK 0x8b
@@ -175,6 +181,16 @@ MODULE_DEVICE_TABLE(usb, id_table);
#define PL2303_HXN_FLOWCTRL_RTS_CTS 0x18
#define PL2303_HXN_FLOWCTRL_XON_XOFF 0x0c
+#define PL256X_PORT_A_FLOWCTRL_REG 0xc005
+#define PL256X_PORT_B_FLOWCTRL_REG 0xd005
+#define PL256X_PORT_C_FLOWCTRL_REG 0xe005
+#define PL256X_PORT_D_FLOWCTRL_REG 0xf005
+
+#define PL256X_FLOWCTRL_MASK 0x43
+#define PL256X_FLOWCTRL_XON_XOFF 0x40
+#define PL256X_FLOWCTRL_RTS_CTS 0x03
+#define PL256X_FLOWCTRL_NONE 0x00
+
static int pl2303_set_break(struct usb_serial_port *port, bool enable);
enum pl2303_type {
@@ -184,6 +200,7 @@ enum pl2303_type {
TYPE_TB,
TYPE_HXD,
TYPE_HXN,
+ TYPE_MP,
TYPE_COUNT
};
@@ -199,6 +216,8 @@ struct pl2303_type_data {
struct pl2303_serial_private {
const struct pl2303_type_data *type;
unsigned long quirks;
+ u16 interface_num;
+ u16 flowctrl_reg;
};
struct pl2303_private {
@@ -239,8 +258,30 @@ static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
.max_baud_rate = 12000000,
.no_divisors = true,
},
+ [TYPE_MP] = {
+ .name = "MP",
+ .max_baud_rate = 24000000,
+ .no_divisors = true,
+ },
};
+static int pl256x_uart_reset(struct usb_serial *serial)
+{
+ struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+ struct device *dev = &serial->interface->dev;
+ int res;
+
+ res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+ PL256X_RESET_REQUEST, PL256X_RESET_REQUEST_TYPE,
+ 0, spriv->interface_num, NULL, 0, 100);
+ if (res) {
+ dev_err(dev, "failed to reset device: %d\n", res);
+ return res;
+ }
+
+ return 0;
+}
+
static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
unsigned char buf[1])
{
@@ -251,6 +292,8 @@ static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
if (spriv->type == &pl2303_type_data[TYPE_HXN])
request = VENDOR_READ_NREQUEST;
+ else if (spriv->type == &pl2303_type_data[TYPE_MP])
+ request = VENDOR_READ_MPREQUEST;
else
request = VENDOR_READ_REQUEST;
@@ -282,6 +325,8 @@ static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
if (spriv->type == &pl2303_type_data[TYPE_HXN])
request = VENDOR_WRITE_NREQUEST;
+ else if (spriv->type == &pl2303_type_data[TYPE_MP])
+ request = VENDOR_WRITE_MPREQUEST;
else
request = VENDOR_WRITE_REQUEST;
@@ -307,10 +352,12 @@ static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
if (!buf)
return -ENOMEM;
- if (spriv->type == &pl2303_type_data[TYPE_HXN])
+ if (spriv->type == &pl2303_type_data[TYPE_HXN] ||
+ spriv->type == &pl2303_type_data[TYPE_MP]) {
ret = pl2303_vendor_read(serial, reg, buf);
- else
+ } else {
ret = pl2303_vendor_read(serial, reg | 0x80, buf);
+ }
if (ret)
goto out_free;
@@ -461,6 +508,14 @@ static int pl2303_detect_type(struct usb_serial *serial)
case 0x905: /* GT-2AB */
case 0x1005: /* GC-Q20 */
return TYPE_HXN;
+ case 0x3302: /* PL2533 VC 2 Port */
+ case 0x3304: /* PL2533 VC 4 Port */
+ case 0x4302: /* PL2543 VC 2 Port */
+ case 0x4304: /* PL2543 VC 4 Port */
+ case 0x6502: /* PL2565 VC 2 Port */
+ case 0x6504: /* PL2565 VC 4 Port */
+ case 0x6506: /* PL2565 VC 4 Port QFN64 package */
+ return TYPE_MP;
}
break;
}
@@ -494,6 +549,7 @@ static int pl2303_startup(struct usb_serial *serial)
struct pl2303_serial_private *spriv;
enum pl2303_type type;
unsigned char *buf;
+ unsigned int ifnum;
int ret;
ret = pl2303_detect_type(serial);
@@ -503,20 +559,43 @@ static int pl2303_startup(struct usb_serial *serial)
type = ret;
dev_dbg(&serial->interface->dev, "device type: %s\n", pl2303_type_data[type].name);
+ ifnum = serial->interface->altsetting->desc.bInterfaceNumber;
+
spriv = kzalloc_obj(*spriv);
if (!spriv)
return -ENOMEM;
+ if (type == TYPE_MP) {
+ switch (ifnum) {
+ case 0:
+ spriv->flowctrl_reg = PL256X_PORT_A_FLOWCTRL_REG;
+ break;
+ case 1:
+ spriv->flowctrl_reg = PL256X_PORT_B_FLOWCTRL_REG;
+ break;
+ case 2:
+ spriv->flowctrl_reg = PL256X_PORT_C_FLOWCTRL_REG;
+ break;
+ case 3:
+ spriv->flowctrl_reg = PL256X_PORT_D_FLOWCTRL_REG;
+ break;
+ default:
+ kfree(spriv);
+ return -ENODEV;
+ }
+ }
+
spriv->type = &pl2303_type_data[type];
spriv->quirks = (unsigned long)usb_get_serial_data(serial);
spriv->quirks |= spriv->type->quirks;
+ spriv->interface_num = ifnum;
if (type == TYPE_HXD && pl2303_is_hxd_clone(serial))
spriv->quirks |= PL2303_QUIRK_NO_BREAK_GETLINE;
usb_set_serial_data(serial, spriv);
- if (type != TYPE_HXN) {
+ if (type != TYPE_HXN && type != TYPE_MP) {
buf = kmalloc(1, GFP_KERNEL);
if (!buf) {
kfree(spriv);
@@ -578,13 +657,15 @@ static void pl2303_port_remove(struct usb_serial_port *port)
static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
{
struct usb_device *dev = port->serial->dev;
+ struct usb_serial *serial = port->serial;
+ struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
int retval;
dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
- value, 0, NULL, 0, 100);
+ value, spriv->interface_num, NULL, 0, 100);
if (retval)
dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
@@ -764,7 +845,7 @@ static int pl2303_get_line_request(struct usb_serial_port *port,
ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
- 0, 0, buf, 7, 100);
+ 0, spriv->interface_num, buf, 7, 100);
if (ret != 7) {
dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
@@ -783,11 +864,13 @@ static int pl2303_set_line_request(struct usb_serial_port *port,
unsigned char buf[7])
{
struct usb_device *udev = port->serial->dev;
+ struct usb_serial *serial = port->serial;
+ struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
int ret;
ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
- 0, 0, buf, 7, 100);
+ 0, spriv->interface_num, buf, 7, 100);
if (ret < 0) {
dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
return ret;
@@ -942,6 +1025,9 @@ static void pl2303_set_termios(struct tty_struct *tty,
pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
PL2303_HXN_FLOWCTRL_MASK,
PL2303_HXN_FLOWCTRL_RTS_CTS);
+ } else if (spriv->type == &pl2303_type_data[TYPE_MP]) {
+ pl2303_vendor_write(serial, spriv->flowctrl_reg,
+ PL256X_FLOWCTRL_RTS_CTS);
} else {
pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x60);
}
@@ -950,6 +1036,9 @@ static void pl2303_set_termios(struct tty_struct *tty,
pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
PL2303_HXN_FLOWCTRL_MASK,
PL2303_HXN_FLOWCTRL_XON_XOFF);
+ } else if (spriv->type == &pl2303_type_data[TYPE_MP]) {
+ pl2303_vendor_write(serial, spriv->flowctrl_reg,
+ PL256X_FLOWCTRL_XON_XOFF);
} else {
pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
}
@@ -958,6 +1047,9 @@ static void pl2303_set_termios(struct tty_struct *tty,
pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
PL2303_HXN_FLOWCTRL_MASK,
PL2303_HXN_FLOWCTRL_NONE);
+ } else if (spriv->type == &pl2303_type_data[TYPE_MP]) {
+ pl2303_vendor_write(serial, spriv->flowctrl_reg,
+ PL256X_FLOWCTRL_NONE);
} else {
pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
}
@@ -1005,6 +1097,8 @@ static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
PL2303_HXN_RESET_UPSTREAM_PIPE |
PL2303_HXN_RESET_DOWNSTREAM_PIPE);
+ } else if (spriv->type == &pl2303_type_data[TYPE_MP]) {
+ pl256x_uart_reset(serial);
} else {
pl2303_vendor_write(serial, 8, 0);
pl2303_vendor_write(serial, 9, 0);
@@ -1115,7 +1209,7 @@ static int pl2303_set_break(struct usb_serial_port *port, bool enable)
result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
- 0, NULL, 0, 100);
+ spriv->interface_num, NULL, 0, 100);
if (result) {
dev_err(&port->dev, "error sending break = %d\n", result);
return result;
diff --git a/drivers/usb/serial/pl2303.h b/drivers/usb/serial/pl2303.h
index d60eda7f6eda..8eb1e7b5d3ec 100644
--- a/drivers/usb/serial/pl2303.h
+++ b/drivers/usb/serial/pl2303.h
@@ -26,7 +26,7 @@
#define PL2303_PRODUCT_ID_HCR331 0x331a
#define PL2303_PRODUCT_ID_MOTOROLA 0x0307
#define PL2303_PRODUCT_ID_ZTEK 0xe1f1
-
+#define PL256X_PRODUCT_ID_4P 0x2533
#define ATEN_VENDOR_ID 0x0557
#define ATEN_VENDOR_ID2 0x0547
--
2.51.0
reply other threads:[~2026-07-21 11:25 UTC|newest]
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