diff options
| author | Philippe Schenker <philippe.schenker@toradex.com> | 2019-10-09 17:18:28 +0200 |
|---|---|---|
| committer | Philippe Schenker <philippe.schenker@toradex.com> | 2020-08-13 16:04:46 +0200 |
| commit | 9ac740179010c506961430db4bb94b4f66b0709e (patch) | |
| tree | 1f02ca9a0fe131ba3f2f1cd3d3fafacf6d9570bf /drivers/tty/serial/fsl_lpuart.c | |
| parent | a201317f066aa6db0ba77595a3bf41ae6d650ee3 (diff) | |
tty: serial: lpuart: Add RS485 support for 32-bit uart flavour
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
(cherry picked from commit 8b4f8d8212a9691a3046c228cf6561543b4e159b)
Conflicts:
drivers/tty/serial/fsl_lpuart.c
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Diffstat (limited to 'drivers/tty/serial/fsl_lpuart.c')
| -rw-r--r-- | drivers/tty/serial/fsl_lpuart.c | 58 |
1 files changed, 56 insertions, 2 deletions
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 6a875fdaea09..60ecb0c2383c 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1472,6 +1472,57 @@ 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) + & ~(UARTMODIR_TXRTSPOL | UARTMODIR_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 |= UARTMODIR_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 &= ~UARTMODIR_TXRTSPOL; + else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) + modem |= UARTMODIR_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; @@ -2732,7 +2783,10 @@ static int lpuart_probe(struct platform_device *pdev) sport->port.ops = &lpuart_pops; sport->port.flags = UPF_BOOT_AUTOCONF; - sport->port.rs485_config = lpuart_config_rs485; + if (lpuart_is_32(sport)) + sport->port.rs485_config = lpuart32_config_rs485; + else + sport->port.rs485_config = lpuart_config_rs485; ret = lpuart_attach_pd(&pdev->dev); if (ret) @@ -2815,7 +2869,7 @@ 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) |