* [PATCH v2 1/3] tty: serial: lpuart: Remove unnecessary code from set_mctrl
@ 2019-10-17 14:14 Philippe Schenker
2019-10-17 14:14 ` [PATCH v2 2/3] tty: serial: lpuart: Use defines that correspond to correct register Philippe Schenker
2019-10-17 14:14 ` [PATCH v2 3/3] tty: serial: lpuart: Add RS485 support for 32-bit uart flavour Philippe Schenker
0 siblings, 2 replies; 3+ messages in thread
From: Philippe Schenker @ 2019-10-17 14:14 UTC (permalink / raw)
To: Greg Kroah-Hartman, linux-serial
Cc: Max Krummenacher, Jiri Slaby, linux-kernel, Fugang Duan,
Stefan Agner, linux-imx, Andrey Smirnov, Philippe Schenker
Currently flow control is not working due to lpuart32_set_mctrl that is
clearing TXCTSE bit in all cases. This bit gets earlier setup by
lpuart32_set_termios.
As I read in Documentation set_mctrl is also not meant for hardware
flow control rather than gpio setting and clearing a RTS signal.
Therefore I guess it is safe to remove the whole code in
lpuart32_set_mctrl.
This was tested with console on a i.MX8QXP SoC.
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
---
Changes in v2:
- Added Fugang Duan's review
drivers/tty/serial/fsl_lpuart.c | 11 -----------
1 file changed, 11 deletions(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 537896c4d887..f3271857621c 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1333,18 +1333,7 @@ static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
- unsigned long temp;
-
- temp = lpuart32_read(port, UARTMODIR) &
- ~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE);
-
- if (mctrl & TIOCM_RTS)
- temp |= UARTMODIR_RXRTSE;
-
- if (mctrl & TIOCM_CTS)
- temp |= UARTMODIR_TXCTSE;
- lpuart32_write(port, temp, UARTMODIR);
}
static void lpuart_break_ctl(struct uart_port *port, int break_state)
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v2 2/3] tty: serial: lpuart: Use defines that correspond to correct register
2019-10-17 14:14 [PATCH v2 1/3] tty: serial: lpuart: Remove unnecessary code from set_mctrl Philippe Schenker
@ 2019-10-17 14:14 ` Philippe Schenker
2019-10-17 14:14 ` [PATCH v2 3/3] tty: serial: lpuart: Add RS485 support for 32-bit uart flavour Philippe Schenker
1 sibling, 0 replies; 3+ messages in thread
From: Philippe Schenker @ 2019-10-17 14:14 UTC (permalink / raw)
To: Greg Kroah-Hartman, linux-serial
Cc: Max Krummenacher, Jiri Slaby, linux-kernel, Fugang Duan,
Stefan Agner, linux-imx, Andrey Smirnov, Philippe Schenker,
Stefan Agner
Use define from the 32-bit register description UARTMODIR_* instead of
UARTMODEM_*. The value is the same, so there is no functional change.
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Stefan Agner <stefan.agner@toradex.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
---
Changes in v2:
- Changed commit message to Stefans suggestions
- Added Stefan's and Fugang's reviewed tag
drivers/tty/serial/fsl_lpuart.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index f3271857621c..346b4a070ce9 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1879,10 +1879,10 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
}
if (termios->c_cflag & CRTSCTS) {
- modem |= UARTMODEM_RXRTSE | UARTMODEM_TXCTSE;
+ modem |= (UARTMODIR_RXRTSE | UARTMODIR_TXCTSE);
} else {
termios->c_cflag &= ~CRTSCTS;
- modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
+ modem &= ~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE);
}
if (termios->c_cflag & CSTOPB)
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v2 3/3] tty: serial: lpuart: Add RS485 support for 32-bit uart flavour
2019-10-17 14:14 [PATCH v2 1/3] tty: serial: lpuart: Remove unnecessary code from set_mctrl Philippe Schenker
2019-10-17 14:14 ` [PATCH v2 2/3] tty: serial: lpuart: Use defines that correspond to correct register Philippe Schenker
@ 2019-10-17 14:14 ` Philippe Schenker
1 sibling, 0 replies; 3+ messages in thread
From: Philippe Schenker @ 2019-10-17 14:14 UTC (permalink / raw)
To: Greg Kroah-Hartman, linux-serial
Cc: Max Krummenacher, Jiri Slaby, linux-kernel, Fugang Duan,
Stefan Agner, linux-imx, Andrey Smirnov, Philippe Schenker
This commits adds RS485 support for LPUART hardware that uses 32-bit
registers. These are typically found in i.MX8 processors.
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
---
Changes in v2:
- Added Fugang's reviewed tag
drivers/tty/serial/fsl_lpuart.c | 65 ++++++++++++++++++++++++++++++++-
1 file changed, 63 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 346b4a070ce9..22df5f8f48b6 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -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 {
@@ -2405,7 +2463,10 @@ 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;
sport->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(sport->ipg_clk)) {
@@ -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)
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-10-17 14:14 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2019-10-17 14:14 [PATCH v2 1/3] tty: serial: lpuart: Remove unnecessary code from set_mctrl Philippe Schenker
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2019-10-17 14:14 ` [PATCH v2 3/3] tty: serial: lpuart: Add RS485 support for 32-bit uart flavour Philippe Schenker
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