From: Lino Sanfilippo <LinoSanfilippo@gmx.de>
To: gregkh@linuxfoundation.org, jirislaby@kernel.org,
u.kleine-koenig@pengutronix.de
Cc: linux@armlinux.org.uk, richard.genoud@gmail.com,
nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com,
ludovic.desroches@microchip.com, shawnguo@kernel.org,
s.hauer@pengutronix.de, kernel@pengutronix.de,
festevam@gmail.com, linux-imx@nxp.com, mcoquelin.stm32@gmail.com,
alexandre.torgue@foss.st.com, linux-serial@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-stm32@st-md-mailman.stormreply.com, lukas@wunner.de,
Lino Sanfilippo <LinoSanfilippo@gmx.de>
Subject: [PATCH 2 1/9] serial: core: move RS485 configuration tasks from drivers into core
Date: Wed, 16 Feb 2022 01:17:55 +0100 [thread overview]
Message-ID: <20220216001803.637-2-LinoSanfilippo@gmx.de> (raw)
In-Reply-To: <20220216001803.637-1-LinoSanfilippo@gmx.de>
Several drivers that support setting the RS485 configuration via userspace
implement one or more of the following tasks:
- in case of an invalid RTS configuration (both RTS after send and RTS on
send set or both unset) fall back to enable RTS on send and disable RTS
after send
- nullify the padding field of the returned serial_rs485 struct
- copy the configuration into the uart port struct
- limit RTS delays to 100 ms
Move these tasks into the serial core to make them generic and to provide
a consistent behaviour among all drivers.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
drivers/tty/serial/serial_core.c | 18 ++++++++++++++++++
include/uapi/linux/serial.h | 3 +++
2 files changed, 21 insertions(+)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 846192a7b4bf..a4f7e847d414 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1282,8 +1282,26 @@ static int uart_set_rs485_config(struct uart_port *port,
if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
return -EFAULT;
+ /* pick sane settings if the user hasn't */
+ if (!(rs485.flags & SER_RS485_RTS_ON_SEND) ==
+ !(rs485.flags & SER_RS485_RTS_AFTER_SEND)) {
+ rs485.flags |= SER_RS485_RTS_ON_SEND;
+ rs485.flags &= ~SER_RS485_RTS_AFTER_SEND;
+ }
+
+ rs485.delay_rts_before_send = min_t(unsigned int,
+ rs485.delay_rts_before_send,
+ SER_RS485_MAX_RTS_DELAY);
+ rs485.delay_rts_after_send = min_t(unsigned int,
+ rs485.delay_rts_after_send,
+ SER_RS485_MAX_RTS_DELAY);
+ /* Return clean padding area to userspace */
+ memset(rs485.padding, 0, sizeof(rs485.padding));
+
spin_lock_irqsave(&port->lock, flags);
ret = port->rs485_config(port, &rs485);
+ if (!ret)
+ port->rs485 = rs485;
spin_unlock_irqrestore(&port->lock, flags);
if (ret)
return ret;
diff --git a/include/uapi/linux/serial.h b/include/uapi/linux/serial.h
index fa6b16e5fdd8..859045a53231 100644
--- a/include/uapi/linux/serial.h
+++ b/include/uapi/linux/serial.h
@@ -128,6 +128,9 @@ struct serial_rs485 {
(if supported) */
__u32 delay_rts_before_send; /* Delay before send (milliseconds) */
__u32 delay_rts_after_send; /* Delay after send (milliseconds) */
+#define SER_RS485_MAX_RTS_DELAY 100 /* Max time with active
+ RTS before/after
+ data sent (msecs) */
__u32 padding[5]; /* Memory is cheap, new structs
are a royal PITA .. */
};
base-commit: 802d00bd774b77fe132e9e83462b96fb9919411c
--
2.34.1
next prev parent reply other threads:[~2022-02-16 0:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-16 0:17 Move RS485 implementation from drivers to serial core Lino Sanfilippo
2022-02-16 0:17 ` Lino Sanfilippo [this message]
2022-02-17 11:33 ` [PATCH 2 1/9] serial: core: move RS485 configuration tasks from drivers into core Lukas Wunner
2022-02-17 21:36 ` Lino Sanfilippo
2022-02-21 18:39 ` Greg KH
2022-02-21 23:19 ` Lino Sanfilippo
2022-02-16 0:17 ` [PATCH 2 2/9] serial: amba-pl011: remove redundant code in rs485_config Lino Sanfilippo
2022-02-16 0:17 ` [PATCH 2 3/9] serial: stm32: " Lino Sanfilippo
2022-02-16 0:17 ` [PATCH 2 4/9] serial: sc16is7xx: remove redundant check " Lino Sanfilippo
2022-02-17 11:47 ` Lukas Wunner
2022-02-17 22:11 ` Lino Sanfilippo
2022-02-16 0:17 ` [PATCH 2 5/9] serial: omap: remove redundant code " Lino Sanfilippo
2022-02-16 0:18 ` [PATCH 2 6/9] serial: max310: remove redundant memset " Lino Sanfilippo
2022-02-16 0:18 ` [PATCH 2 7/9] serial: imx: remove redundant assignment " Lino Sanfilippo
2022-02-16 17:43 ` Uwe Kleine-König
2022-02-16 0:18 ` [PATCH 2 8/9] serial: fsl_lpuart: remove redundant code in rs485_config functions Lino Sanfilippo
2022-02-16 0:18 ` [PATCH 2 9/9] serial: atmel: remove redundant assignment in rs485_config Lino Sanfilippo
2022-02-17 9:22 ` Richard Genoud
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