* [PATCH 5.15 111/120] serial: stm32: Factor out GPIO RTS toggling into separate function
[not found] <20221205190806.528972574@linuxfoundation.org>
@ 2022-12-05 19:10 ` Greg Kroah-Hartman
2022-12-05 19:10 ` [PATCH 5.15 112/120] serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2022-12-05 19:10 UTC (permalink / raw)
To: stable, linux-serial
Cc: Greg Kroah-Hartman, patches, Marek Vasut, Alexandre Torgue,
Erwan Le Ray, Jean Philippe Romain, Valentin Caron,
linux-arm-kernel, linux-stm32, Sasha Levin
From: Marek Vasut <marex@denx.de>
[ Upstream commit 3bcea529b295a993b1b05db63f245ae8030c5acf ]
Pull out the GPIO RTS enable and disable handling into separate function.
Limit the scope of GPIO RTS toggling only to GPIO emulated RS485 too.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Erwan Le Ray <erwan.leray@foss.st.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jean Philippe Romain <jean-philippe.romain@foss.st.com>
Cc: Valentin Caron <valentin.caron@foss.st.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/20220430162845.244655-1-marex@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/stm32-usart.c | 61 ++++++++++++++++++++------------
1 file changed, 38 insertions(+), 23 deletions(-)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index fc166cc2c856..f2cef5f7ae5a 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -325,6 +325,42 @@ static void stm32_usart_tx_interrupt_disable(struct uart_port *port)
stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
}
+static void stm32_usart_rs485_rts_enable(struct uart_port *port)
+{
+ struct stm32_port *stm32_port = to_stm32_port(port);
+ struct serial_rs485 *rs485conf = &port->rs485;
+
+ if (stm32_port->hw_flow_control ||
+ !(rs485conf->flags & SER_RS485_ENABLED))
+ return;
+
+ if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+ mctrl_gpio_set(stm32_port->gpios,
+ stm32_port->port.mctrl | TIOCM_RTS);
+ } else {
+ mctrl_gpio_set(stm32_port->gpios,
+ stm32_port->port.mctrl & ~TIOCM_RTS);
+ }
+}
+
+static void stm32_usart_rs485_rts_disable(struct uart_port *port)
+{
+ struct stm32_port *stm32_port = to_stm32_port(port);
+ struct serial_rs485 *rs485conf = &port->rs485;
+
+ if (stm32_port->hw_flow_control ||
+ !(rs485conf->flags & SER_RS485_ENABLED))
+ return;
+
+ if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+ mctrl_gpio_set(stm32_port->gpios,
+ stm32_port->port.mctrl & ~TIOCM_RTS);
+ } else {
+ mctrl_gpio_set(stm32_port->gpios,
+ stm32_port->port.mctrl | TIOCM_RTS);
+ }
+}
+
static void stm32_usart_transmit_chars_pio(struct uart_port *port)
{
struct stm32_port *stm32_port = to_stm32_port(port);
@@ -566,41 +602,20 @@ static void stm32_usart_disable_ms(struct uart_port *port)
/* Transmit stop */
static void stm32_usart_stop_tx(struct uart_port *port)
{
- struct stm32_port *stm32_port = to_stm32_port(port);
- struct serial_rs485 *rs485conf = &port->rs485;
-
stm32_usart_tx_interrupt_disable(port);
- if (rs485conf->flags & SER_RS485_ENABLED) {
- if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
- mctrl_gpio_set(stm32_port->gpios,
- stm32_port->port.mctrl & ~TIOCM_RTS);
- } else {
- mctrl_gpio_set(stm32_port->gpios,
- stm32_port->port.mctrl | TIOCM_RTS);
- }
- }
+ stm32_usart_rs485_rts_disable(port);
}
/* There are probably characters waiting to be transmitted. */
static void stm32_usart_start_tx(struct uart_port *port)
{
- struct stm32_port *stm32_port = to_stm32_port(port);
- struct serial_rs485 *rs485conf = &port->rs485;
struct circ_buf *xmit = &port->state->xmit;
if (uart_circ_empty(xmit) && !port->x_char)
return;
- if (rs485conf->flags & SER_RS485_ENABLED) {
- if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
- mctrl_gpio_set(stm32_port->gpios,
- stm32_port->port.mctrl | TIOCM_RTS);
- } else {
- mctrl_gpio_set(stm32_port->gpios,
- stm32_port->port.mctrl & ~TIOCM_RTS);
- }
- }
+ stm32_usart_rs485_rts_enable(port);
stm32_usart_transmit_chars(port);
}
--
2.35.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH 5.15 112/120] serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode
[not found] <20221205190806.528972574@linuxfoundation.org>
2022-12-05 19:10 ` [PATCH 5.15 111/120] serial: stm32: Factor out GPIO RTS toggling into separate function Greg Kroah-Hartman
@ 2022-12-05 19:10 ` Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2022-12-05 19:10 UTC (permalink / raw)
To: stable, linux-serial
Cc: Greg Kroah-Hartman, patches, Marek Vasut, Alexandre Torgue,
Erwan Le Ray, Jean Philippe Romain, Valentin Caron,
linux-arm-kernel, linux-stm32, Sasha Levin
From: Marek Vasut <marex@denx.de>
[ Upstream commit d7c76716169ddc37cf6316ff381d34ea807fbfd7 ]
In case the RS485 mode is emulated using GPIO RTS, use the TC interrupt
to deassert the GPIO RTS, otherwise the GPIO RTS stays asserted after a
transmission ended and the RS485 cannot work.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Erwan Le Ray <erwan.leray@foss.st.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jean Philippe Romain <jean-philippe.romain@foss.st.com>
Cc: Valentin Caron <valentin.caron@foss.st.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/20220430162845.244655-2-marex@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/stm32-usart.c | 42 ++++++++++++++++++++++++++++++--
drivers/tty/serial/stm32-usart.h | 1 +
2 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index f2cef5f7ae5a..86f044a96de1 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -314,6 +314,14 @@ static void stm32_usart_tx_interrupt_enable(struct uart_port *port)
stm32_usart_set_bits(port, ofs->cr1, USART_CR1_TXEIE);
}
+static void stm32_usart_tc_interrupt_enable(struct uart_port *port)
+{
+ struct stm32_port *stm32_port = to_stm32_port(port);
+ const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+ stm32_usart_set_bits(port, ofs->cr1, USART_CR1_TCIE);
+}
+
static void stm32_usart_tx_interrupt_disable(struct uart_port *port)
{
struct stm32_port *stm32_port = to_stm32_port(port);
@@ -325,6 +333,14 @@ static void stm32_usart_tx_interrupt_disable(struct uart_port *port)
stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
}
+static void stm32_usart_tc_interrupt_disable(struct uart_port *port)
+{
+ struct stm32_port *stm32_port = to_stm32_port(port);
+ const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+ stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TCIE);
+}
+
static void stm32_usart_rs485_rts_enable(struct uart_port *port)
{
struct stm32_port *stm32_port = to_stm32_port(port);
@@ -462,6 +478,13 @@ static void stm32_usart_transmit_chars(struct uart_port *port)
u32 isr;
int ret;
+ if (!stm32_port->hw_flow_control &&
+ port->rs485.flags & SER_RS485_ENABLED) {
+ stm32_port->txdone = false;
+ stm32_usart_tc_interrupt_disable(port);
+ stm32_usart_rs485_rts_enable(port);
+ }
+
if (port->x_char) {
if (stm32_port->tx_dma_busy)
stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
@@ -501,8 +524,14 @@ static void stm32_usart_transmit_chars(struct uart_port *port)
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
- if (uart_circ_empty(xmit))
+ if (uart_circ_empty(xmit)) {
stm32_usart_tx_interrupt_disable(port);
+ if (!stm32_port->hw_flow_control &&
+ port->rs485.flags & SER_RS485_ENABLED) {
+ stm32_port->txdone = true;
+ stm32_usart_tc_interrupt_enable(port);
+ }
+ }
}
static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
@@ -515,6 +544,13 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
sr = readl_relaxed(port->membase + ofs->isr);
+ if (!stm32_port->hw_flow_control &&
+ port->rs485.flags & SER_RS485_ENABLED &&
+ (sr & USART_SR_TC)) {
+ stm32_usart_tc_interrupt_disable(port);
+ stm32_usart_rs485_rts_disable(port);
+ }
+
if ((sr & USART_SR_RTOF) && ofs->icr != UNDEF_REG)
writel_relaxed(USART_ICR_RTOCF,
port->membase + ofs->icr);
@@ -612,8 +648,10 @@ static void stm32_usart_start_tx(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
- if (uart_circ_empty(xmit) && !port->x_char)
+ if (uart_circ_empty(xmit) && !port->x_char) {
+ stm32_usart_rs485_rts_disable(port);
return;
+ }
stm32_usart_rs485_rts_enable(port);
diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h
index 07ac291328cd..ad6335155de2 100644
--- a/drivers/tty/serial/stm32-usart.h
+++ b/drivers/tty/serial/stm32-usart.h
@@ -267,6 +267,7 @@ struct stm32_port {
bool hw_flow_control;
bool swap; /* swap RX & TX pins */
bool fifoen;
+ bool txdone;
int rxftcfg; /* RX FIFO threshold CFG */
int txftcfg; /* TX FIFO threshold CFG */
bool wakeup_src;
--
2.35.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
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[not found] <20221205190806.528972574@linuxfoundation.org>
2022-12-05 19:10 ` [PATCH 5.15 111/120] serial: stm32: Factor out GPIO RTS toggling into separate function Greg Kroah-Hartman
2022-12-05 19:10 ` [PATCH 5.15 112/120] serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode Greg Kroah-Hartman
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