tty: serial: lpuart: Add RS485 support for 32-bit uart flavour (67b01837) · Commits · 戴 / test

drivers/tty/serial/fsl_lpuart.c

+63 −2

Original line number	Diff line number	Diff line
		@@ -1280,6 +1280,57 @@ static int lpuart_config_rs485(struct uart_port *port,
		return 0;
		}

		static int lpuart32_config_rs485(struct uart_port *port,
		struct serial_rs485 *rs485)
		{
		struct lpuart_port *sport = container_of(port,
		struct lpuart_port, port);

		unsigned long modem = lpuart32_read(&sport->port, UARTMODIR)
		& ~(UARTMODEM_TXRTSPOL \| UARTMODEM_TXRTSE);
		lpuart32_write(&sport->port, modem, UARTMODIR);

		/* clear unsupported configurations */
		rs485->delay_rts_before_send = 0;
		rs485->delay_rts_after_send = 0;
		rs485->flags &= ~SER_RS485_RX_DURING_TX;

		if (rs485->flags & SER_RS485_ENABLED) {
		/* Enable auto RS-485 RTS mode */
		modem \|= UARTMODEM_TXRTSE;

		/*
		* RTS needs to be logic HIGH either during transer _or_ after
		* transfer, other variants are not supported by the hardware.
		*/

		if (!(rs485->flags & (SER_RS485_RTS_ON_SEND \|
		SER_RS485_RTS_AFTER_SEND)))
		rs485->flags \|= SER_RS485_RTS_ON_SEND;

		if (rs485->flags & SER_RS485_RTS_ON_SEND &&
		rs485->flags & SER_RS485_RTS_AFTER_SEND)
		rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;

		/*
		* The hardware defaults to RTS logic HIGH while transfer.
		* Switch polarity in case RTS shall be logic HIGH
		* after transfer.
		* Note: UART is assumed to be active high.
		*/
		if (rs485->flags & SER_RS485_RTS_ON_SEND)
		modem &= ~UARTMODEM_TXRTSPOL;
		else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
		modem \|= UARTMODEM_TXRTSPOL;
		}

		/* Store the new configuration */
		sport->port.rs485 = *rs485;

		lpuart32_write(&sport->port, modem, UARTMODIR);
		return 0;
		}

		static unsigned int lpuart_get_mctrl(struct uart_port *port)
		{
		unsigned int temp = 0;
		@@ -1878,6 +1929,13 @@ lpuart32_set_termios(struct uart_port port, struct ktermios termios,
		ctrl \|= UARTCTRL_M;
		}

		/*
		* When auto RS-485 RTS mode is enabled,
		* hardware flow control need to be disabled.
		*/
		if (sport->port.rs485.flags & SER_RS485_ENABLED)
		termios->c_cflag &= ~CRTSCTS;

		if (termios->c_cflag & CRTSCTS) {
		modem \|= (UARTMODIR_RXRTSE \| UARTMODIR_TXCTSE);
		} else {
		@@ -2405,6 +2463,9 @@ static int lpuart_probe(struct platform_device *pdev)
		sport->port.ops = &lpuart_pops;
		sport->port.flags = UPF_BOOT_AUTOCONF;

		if (lpuart_is_32(sport))
		sport->port.rs485_config = lpuart32_config_rs485;
		else
		sport->port.rs485_config = lpuart_config_rs485;

		sport->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
		@@ -2459,7 +2520,7 @@ static int lpuart_probe(struct platform_device *pdev)
		sport->port.rs485.delay_rts_after_send)
		dev_err(&pdev->dev, "driver doesn't support RTS delays\n");

		lpuart_config_rs485(&sport->port, &sport->port.rs485);
		sport->port.rs485_config(&sport->port, &sport->port.rs485);

		sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx");
		if (!sport->dma_tx_chan)

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