Pull-Up mode is disabled (default) in PL2303HXD. When the Pull-Up mode is activated, its TX/DTR/RTS external resistor will start the output function.
How to enable the Pull-Up mode of PL2303HXD 1.TX/DTR/RTS external resistor is required on the circuit diagram (PCB) 2.PL2303HXD OTP needs to be programmed to have a Pull-Up mode through 6.5V (USB_VCC,5V->6.5V) The patch driver will read whether the PL2303HXD has a Pull-Up mode,and if so, it will be set to enable Pull-Up mode function. Signed-off-by: Charles Yeh <[email protected]> --- drivers/usb/serial/pl2303.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index bb3f9aa4a909..e5d00e4a495d 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -145,6 +145,16 @@ MODULE_DEVICE_TABLE(usb, id_table); #define UART_OVERRUN_ERROR 0x40 #define UART_CTS 0x80 +#define TYPE_HX_READ_PUM_STATUS_REG 0x8484 +#define TYPE_HX_READ_PUM_ADD 0x0404 +#define TYPE_HX_READ_PUM_DATA_REG 0x8383 +#define TYPE_HX_PULLUP_MODE_DATA 0x08 +#define TYPE_HX_PULLUP_MODE_REG 0x09 +#define TYPE_HX_PUM_ADD0 0x00 +#define TYPE_HX_PUM_DATA0 0x31 +#define TYPE_HX_PUM_ADD1 0x01 +#define TYPE_HX_PUM_DATA1 0x08 + static void pl2303_set_break(struct usb_serial_port *port, bool enable); enum pl2303_type { @@ -688,6 +698,20 @@ static void pl2303_set_termios(struct tty_struct *tty, pl2303_vendor_write(serial, 0x0, 0x0); } + if (spriv->type == &pl2303_type_data[TYPE_HX]) { + pl2303_vendor_read(serial, TYPE_HX_READ_PUM_STATUS_REG, buf); + pl2303_vendor_write(serial, TYPE_HX_READ_PUM_ADD, + TYPE_HX_PULLUP_MODE_REG); + pl2303_vendor_read(serial, TYPE_HX_READ_PUM_STATUS_REG, buf); + pl2303_vendor_read(serial, TYPE_HX_READ_PUM_DATA_REG, buf); + if (*buf == TYPE_HX_PULLUP_MODE_DATA) { + pl2303_vendor_write(serial, TYPE_HX_PUM_ADD0, + TYPE_HX_PUM_DATA0); + pl2303_vendor_write(serial, TYPE_HX_PUM_ADD1, + TYPE_HX_PUM_DATA1); + } + } + kfree(buf); } -- 2.19.1
