[PATCH 2 1/9] serial: core: move RS485 configuration tasks from drivers into core
flat view
STALE1707d
From: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Date: 2022-02-16 00:19:27
Also in:
linux-serial, lkml
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel