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From: Martin Kepplinger <martin.kepplinger@ginzinger.com>
To: <gregkh@linuxfoundation.org>, <robh+dt@kernel.org>,
<mark.rutland@arm.com>, <jslaby@suse.com>, <corbet@lwn.net>,
<richard.genoud@gmail.com>, <nicolas.ferre@microchip.com>,
<alexandre.belloni@bootlin.com>,
<ludovic.desroches@microchip.com>, <mcoquelin.stm32@gmail.com>,
<alexandre.torgue@st.com>, <linux-serial@vger.kernel.org>,
<devicetree@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-stm32@st-md-mailman.stormreply.com>
Cc: <linux-kernel@vger.kernel.org>
Subject: [PATCH 4/9] serial: 8250: add support for rs485 RTS delays in microseconds
Date: Wed, 20 Feb 2019 16:27:26 +0100 [thread overview]
Message-ID: <20190220152731.4051-4-martin.kepplinger@ginzinger.com> (raw)
In-Reply-To: <20190220152731.4051-1-martin.kepplinger@ginzinger.com>
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Read struct serial_rs485's flag SER_RS485_DELAY_IN_USEC and apply the delay
accordingly.
Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
---
drivers/tty/serial/8250/8250_omap.c | 13 +++++++++++--
drivers/tty/serial/8250/8250_port.c | 25 +++++++++++++++++++++----
2 files changed, 32 insertions(+), 6 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 0a8316632d75..cbce43ac60b1 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -720,8 +720,17 @@ static int omap_8250_rs485_config(struct uart_port *port,
struct uart_8250_port *up = up_to_u8250p(port);
/* 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);
+ if (rs485->flags & SER_RS485_DELAY_IN_USEC) {
+ rs485->delay_rts_before_send = min(rs485->delay_rts_before_send,
+ 100000U);
+ rs485->delay_rts_after_send = min(rs485->delay_rts_after_send,
+ 100000U);
+ } else {
+ rs485->delay_rts_before_send = min(rs485->delay_rts_before_send,
+ 100U);
+ rs485->delay_rts_after_send = min(rs485->delay_rts_after_send,
+ 100U);
+ }
port->rs485 = *rs485;
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index d2f3310abe54..0cee4aa8323d 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1483,6 +1483,15 @@ static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
hrtimer_start(hrt, t, HRTIMER_MODE_REL);
}
+static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
+{
+ long sec = usec / 1000000;
+ long nsec = (usec % 1000000) * 1000000000;
+ ktime_t t = ktime_set(sec, nsec);
+
+ hrtimer_start(hrt, t, HRTIMER_MODE_REL);
+}
+
static void __stop_tx_rs485(struct uart_8250_port *p)
{
struct uart_8250_em485 *em485 = p->em485;
@@ -1493,8 +1502,12 @@ static void __stop_tx_rs485(struct uart_8250_port *p)
*/
if (p->port.rs485.delay_rts_after_send > 0) {
em485->active_timer = &em485->stop_tx_timer;
- start_hrtimer_ms(&em485->stop_tx_timer,
- p->port.rs485.delay_rts_after_send);
+ if (p->port.rs485.flags & SER_RS485_DELAY_IN_USEC)
+ start_hrtimer_us(&em485->stop_tx_timer,
+ p->port.rs485.delay_rts_after_send);
+ else
+ start_hrtimer_ms(&em485->stop_tx_timer,
+ p->port.rs485.delay_rts_after_send);
} else {
__do_stop_tx_rs485(p);
}
@@ -1600,8 +1613,12 @@ static inline void start_tx_rs485(struct uart_port *port)
if (up->port.rs485.delay_rts_before_send > 0) {
em485->active_timer = &em485->start_tx_timer;
- start_hrtimer_ms(&em485->start_tx_timer,
- up->port.rs485.delay_rts_before_send);
+ if (up->port.rs485.flags & SER_RS485_DELAY_IN_USEC)
+ start_hrtimer_us(&em485->start_tx_timer,
+ up->port.rs485.delay_rts_before_send);
+ else
+ start_hrtimer_ms(&em485->start_tx_timer,
+ up->port.rs485.delay_rts_before_send);
return;
}
}
--
2.20.1
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next prev parent reply other threads:[~2019-02-20 15:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-20 15:27 [PATCH 1/9] serial: uapi: add SER_RS485_DELAY_IN_USEC flag to struct serial_rs485 Martin Kepplinger
2019-02-20 15:27 ` [PATCH 2/9] Documentation: serial-rs485: document SER_RS485_DELAY_IN_USEC flag Martin Kepplinger
2019-02-20 15:27 ` [PATCH 3/9] serial: core: add rs485-rts-delay-us devicetree property for RS485 Martin Kepplinger
2019-02-20 15:27 ` Martin Kepplinger [this message]
2019-02-20 15:27 ` [PATCH 5/9] serial: omap-serial: add support for rs485 RTS delays in microseconds Martin Kepplinger
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