Add support for RS-485 in Exar USB adapters. RS-485 mode is controlled by TIOCGRS485 and TIOCSRS485 ioctls. Gpio mode register is set to enable RS-485. Signed-off-by: Jarkko Sonninen <kasper@xxxxxx> --- drivers/usb/serial/xr_serial.c | 72 +++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c index fdb0aae546c3..edbb6add087c 100644 --- a/drivers/usb/serial/xr_serial.c +++ b/drivers/usb/serial/xr_serial.c @@ -93,6 +93,7 @@ struct xr_txrx_clk_mask { #define XR_GPIO_MODE_SEL_DTR_DSR 0x2 #define XR_GPIO_MODE_SEL_RS485 0x3 #define XR_GPIO_MODE_SEL_RS485_ADDR 0x4 +#define XR_GPIO_MODE_RS485_TX_H 0x8 #define XR_GPIO_MODE_TX_TOGGLE 0x100 #define XR_GPIO_MODE_RX_TOGGLE 0x200 @@ -237,6 +238,8 @@ static const struct xr_type xr_types[] = { struct xr_data { const struct xr_type *type; u8 channel; /* zero-based index or interface number */ + struct serial_rs485 rs485; + spinlock_t lock; }; static int xr_set_reg(struct usb_serial_port *port, u8 channel, u16 reg, u16 val) @@ -629,6 +632,7 @@ static void xr_set_flow_mode(struct tty_struct *tty, struct xr_data *data = usb_get_serial_port_data(port); const struct xr_type *type = data->type; u16 flow, gpio_mode; + unsigned long flags, rs485_flags; int ret; ret = xr_get_reg_uart(port, type->gpio_mode, &gpio_mode); @@ -645,9 +649,16 @@ static void xr_set_flow_mode(struct tty_struct *tty, /* Set GPIO mode for controlling the pins manually by default. */ gpio_mode &= ~XR_GPIO_MODE_SEL_MASK; + spin_lock_irqsave(&data->lock, flags); + rs485_flags = data->rs485.flags; + spin_unlock_irqrestore(&data->lock, flags); + if (rs485_flags & SER_RS485_ENABLED) + gpio_mode |= XR_GPIO_MODE_SEL_RS485 | XR_GPIO_MODE_RS485_TX_H; + else if (C_CRTSCTS(tty) && C_BAUD(tty) != B0) + gpio_mode |= XR_GPIO_MODE_SEL_RTS_CTS; + if (C_CRTSCTS(tty) && C_BAUD(tty) != B0) { dev_dbg(&port->dev, "Enabling hardware flow ctrl\n"); - gpio_mode |= XR_GPIO_MODE_SEL_RTS_CTS; flow = XR_UART_FLOW_MODE_HW; } else if (I_IXON(tty)) { u8 start_char = START_CHAR(tty); @@ -827,6 +838,64 @@ static void xr_set_termios(struct tty_struct *tty, xr_set_flow_mode(tty, port, old_termios); } +static int xr_get_rs485_config(struct tty_struct *tty, + unsigned int __user *argp) +{ + struct usb_serial_port *port = tty->driver_data; + struct xr_data *data = usb_get_serial_port_data(port); + unsigned long flags; + struct serial_rs485 rs485; + + spin_lock_irqsave(&data->lock, flags); + memcpy(&rs485, &data->rs485, sizeof(rs485)); + spin_unlock_irqrestore(&data->lock, flags); + dev_dbg(tty->dev, "%s flags %02x\n", __func__, rs485.flags); + + if (copy_to_user(argp, &rs485, sizeof(rs485))) + return -EFAULT; + + return 0; +} + +static int xr_set_rs485_config(struct tty_struct *tty, + unsigned long __user *argp) +{ + struct usb_serial_port *port = tty->driver_data; + struct xr_data *data = usb_get_serial_port_data(port); + struct serial_rs485 rs485; + unsigned long flags; + + if (copy_from_user(&rs485, argp, sizeof(rs485))) + return -EFAULT; + + dev_dbg(tty->dev, "%s flags %02x\n", __func__, rs485.flags); + rs485.flags &= SER_RS485_ENABLED; + spin_lock_irqsave(&data->lock, flags); + memcpy(&data->rs485, &rs485, sizeof(rs485)); + spin_unlock_irqrestore(&data->lock, flags); + xr_set_flow_mode(tty, port, 0); + + if (copy_to_user(argp, &data->rs485, sizeof(data->rs485))) + return -EFAULT; + + return 0; +} + + +static int xr_ioctl(struct tty_struct *tty, + unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + + switch (cmd) { + case TIOCGRS485: + return xr_get_rs485_config(tty, argp); + case TIOCSRS485: + return xr_set_rs485_config(tty, argp); + } + return -ENOIOCTLCMD; +} + static int xr_open(struct tty_struct *tty, struct usb_serial_port *port) { int ret; @@ -1010,6 +1079,7 @@ static struct usb_serial_driver xr_device = { .set_termios = xr_set_termios, .tiocmget = xr_tiocmget, .tiocmset = xr_tiocmset, + .ioctl = xr_ioctl, .dtr_rts = xr_dtr_rts }; -- 2.34.1