This patch series is an attempt to simplify rs485 implementation in drivers
by moving the following tasks out of the drivers into the serial core:
- ensure sane RTS settings: in case of an invalid configuration (both RTS
after send and RTS on send set or both unset) enable RTS on send and
disable RTS after send
- nullify the padding field of the serial_rs485 struct before it is
returned to userspace
- copy the configuration stored in the serial_rs485 struct to the port
configuration if setting the configuration in the driver was successfull
- limit the RTS delay to 100ms
Redundant code has been removed from the following drivers for now:
- atmel
- fsl_lpuart
- amba
- imx
- max310x
- omap-serial
- sc16is7xx
- stm32-usart
The code has been tested with the amba pl011 driver. This series applies
against Gregs tty-testing branch.
Changes in v2:
- use a makro for max RTS delays and comment it (as requested by Jiri)
- add a comment concerning the memset of a structures padding field
- correct typos in the commit message (found by Uwe)
- rephrase all commit messages to make more clear that function
uart_set_rs485_config() has been extended by checks and other
functionalities (as requested by Uwe)
Changes in v3:
- add warning messages if the serial core corrects RS485 values (as requested by Lukas Wunner)
- dont expose the macro for max RTS delays to userspace (as requested by Greg)
In uart_set_rs485_config() the serial core already ensures that only one of
both options RTS on send or RTS after send is set. It also assigns the
passed serial_rs485 struct to the uart port.
So remove the check and the assignment from the drivers rs485_config()
function to avoid redundancy.
Signed-off-by: Lino Sanfilippo <[email protected]>
---
drivers/tty/serial/fsl_lpuart.c | 32 --------------------------------
1 file changed, 32 deletions(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 7d90c5a530ee..a201be44d68a 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1377,19 +1377,6 @@ static int lpuart_config_rs485(struct uart_port *port,
/* Enable auto RS-485 RTS mode */
modem |= UARTMODEM_TXRTSE;
- /*
- * RTS needs to be logic HIGH either during transfer _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
@@ -1402,9 +1389,6 @@ static int lpuart_config_rs485(struct uart_port *port,
modem |= UARTMODEM_TXRTSPOL;
}
- /* Store the new configuration */
- sport->port.rs485 = *rs485;
-
writeb(modem, sport->port.membase + UARTMODEM);
return 0;
}
@@ -1428,19 +1412,6 @@ static int lpuart32_config_rs485(struct uart_port *port,
/* Enable auto RS-485 RTS mode */
modem |= UARTMODEM_TXRTSE;
- /*
- * RTS needs to be logic HIGH either during transfer _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
@@ -1453,9 +1424,6 @@ static int lpuart32_config_rs485(struct uart_port *port,
modem |= UARTMODEM_TXRTSPOL;
}
- /* Store the new configuration */
- sport->port.rs485 = *rs485;
-
lpuart32_write(&sport->port, modem, UARTMODIR);
return 0;
}
--
2.35.1
In uart_set_rs485_config() the serial core already nullifies the padding
field of the passed serial_rs485 struct before returning it to userspace.
Doing the same in the drivers rs485_config() function is redundant, so
remove the concerning memset in this function.
Signed-off-by: Lino Sanfilippo <[email protected]>
---
drivers/tty/serial/max310x.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index dde0824b2fa5..2ecc5f66deaf 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -1037,7 +1037,6 @@ static int max310x_rs485_config(struct uart_port *port,
rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX |
SER_RS485_ENABLED;
- memset(rs485->padding, 0, sizeof(rs485->padding));
port->rs485 = *rs485;
schedule_work(&one->rs_work);
--
2.35.1
In uart_set_rs485_config() the serial core already ensures that only one of
both options RTS on send or RTS after send is set. It also assigns the
passed serial_rs485 struct to the uart port.
So remove the check and the assignment from the drivers rs485_config()
function to avoid redundancy.
Signed-off-by: Lino Sanfilippo <[email protected]>
---
drivers/tty/serial/stm32-usart.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 1b3a611ac39e..6a014168102c 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -107,8 +107,6 @@ static int stm32_usart_config_rs485(struct uart_port *port,
stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
- port->rs485 = *rs485conf;
-
rs485conf->flags |= SER_RS485_RX_DURING_TX;
if (rs485conf->flags & SER_RS485_ENABLED) {
@@ -128,13 +126,10 @@ static int stm32_usart_config_rs485(struct uart_port *port,
rs485conf->delay_rts_after_send,
baud);
- if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+ if (rs485conf->flags & SER_RS485_RTS_ON_SEND)
cr3 &= ~USART_CR3_DEP;
- rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
- } else {
+ else
cr3 |= USART_CR3_DEP;
- rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
- }
writel_relaxed(cr3, port->membase + ofs->cr3);
writel_relaxed(cr1, port->membase + ofs->cr1);
--
2.35.1
In uart_set_rs485_config() the serial core already ensures that only one of
both options RTS on send or RTS after send is set.
So remove this check from the drivers rs485_config() function to avoid
redundancy.
Signed-off-by: Lino Sanfilippo <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 10 ----------
1 file changed, 10 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 64e7e6c8145f..730f697bb517 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -959,16 +959,6 @@ static int sc16is7xx_config_rs485(struct uart_port *port,
struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
if (rs485->flags & SER_RS485_ENABLED) {
- bool rts_during_rx, rts_during_tx;
-
- rts_during_rx = rs485->flags & SER_RS485_RTS_AFTER_SEND;
- rts_during_tx = rs485->flags & SER_RS485_RTS_ON_SEND;
-
- if (rts_during_rx == rts_during_tx)
- dev_err(port->dev,
- "unsupported RTS signalling on_send:%d after_send:%d - exactly one of RS485 RTS flags should be set\n",
- rts_during_tx, rts_during_rx);
-
/*
* RTS signal is handled by HW, it's timing can't be influenced.
* However, it's sometimes useful to delay TX even without RTS
--
2.35.1
In uart_set_rs485_config() the serial core already clamps the RTS delays.
It also assigns the passed serial_rs485 struct to the uart port.
So remove these tasks from the drivers rs485_config() function to avoid
redundancy.
Signed-off-by: Lino Sanfilippo <[email protected]>
---
drivers/tty/serial/omap-serial.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 0862941862c8..a3afcccfbd96 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1350,18 +1350,11 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
up->ier = 0;
serial_out(up, UART_IER, 0);
- /* Clamp the delays to [0, 100ms] */
- rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
- rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
-
- /* store new config */
- port->rs485 = *rs485;
-
if (up->rts_gpiod) {
/* enable / disable rts */
- val = (port->rs485.flags & SER_RS485_ENABLED) ?
+ val = (rs485->flags & SER_RS485_ENABLED) ?
SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
- val = (port->rs485.flags & val) ? 1 : 0;
+ val = (rs485->flags & val) ? 1 : 0;
gpiod_set_value(up->rts_gpiod, val);
}
@@ -1372,7 +1365,7 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
/* If RS-485 is disabled, make sure the THR interrupt is fired when
* TX FIFO is below the trigger level.
*/
- if (!(port->rs485.flags & SER_RS485_ENABLED) &&
+ if (!(rs485->flags & SER_RS485_ENABLED) &&
(up->scr & OMAP_UART_SCR_TX_EMPTY)) {
up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
serial_out(up, UART_OMAP_SCR, up->scr);
--
2.35.1
In uart_set_rs485_config() the serial core already assigns the passed
serial_rs485 struct to the uart port.
So remove the assignment from the drivers rs485_config() function to avoid
redundancy.
Acked-by: Richard Genoud <[email protected]>
Signed-off-by: Lino Sanfilippo <[email protected]>
---
drivers/tty/serial/atmel_serial.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 73d43919898d..18d3bbdcb7a2 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -299,11 +299,9 @@ static int atmel_config_rs485(struct uart_port *port,
/* Resetting serial mode to RS232 (0x0) */
mode &= ~ATMEL_US_USMODE;
- port->rs485 = *rs485conf;
-
if (rs485conf->flags & SER_RS485_ENABLED) {
dev_dbg(port->dev, "Setting UART to RS485\n");
- if (port->rs485.flags & SER_RS485_RX_DURING_TX)
+ if (rs485conf->flags & SER_RS485_RX_DURING_TX)
atmel_port->tx_done_mask = ATMEL_US_TXRDY;
else
atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
--
2.35.1
In uart_set_rs485_config() the serial core already assigns the passed
serial_rs485 struct to the uart port.
So remove the assignment in the drivers rs485_config() function to avoid
reduncancy.
Acked-by: Uwe Kleine-König <[email protected]>
Signed-off-by: Lino Sanfilippo <[email protected]>
---
drivers/tty/serial/imx.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 0b467ce8d737..ab56ff23e8a9 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1937,8 +1937,6 @@ static int imx_uart_rs485_config(struct uart_port *port,
rs485conf->flags & SER_RS485_RX_DURING_TX)
imx_uart_start_rx(port);
- port->rs485 = *rs485conf;
-
return 0;
}
--
2.35.1