* Re: [PATCH 2/3] serial: st-asc: Provide RTS functionality
@ 2016-12-05 14:11 ` Patrice Chotard
0 siblings, 0 replies; 20+ messages in thread
From: Patrice Chotard @ 2016-12-05 14:11 UTC (permalink / raw)
To: Lee Jones, gregkh, jslaby
Cc: linux-arm-kernel, linux-kernel, kernel, linux-serial
Hi Lee
On 12/02/2016 03:11 PM, Lee Jones wrote:
> Until this point, it has not been possible for serial applications
> to toggle the UART RTS line. This can be useful with certain
> configurations. For example, when using a Mezzanine on a Linaro
> 96board, RTS line is used to take the the on-board microcontroller
typo "the the on"
> in and out of reset.
>
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
> drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> index 379e5bd..ce46898 100644
> --- a/drivers/tty/serial/st-asc.c
> +++ b/drivers/tty/serial/st-asc.c
> @@ -30,6 +30,7 @@
> #include <linux/of_platform.h>
> #include <linux/serial_core.h>
> #include <linux/clk.h>
> +#include <linux/gpio/consumer.h>
>
> #define DRIVER_NAME "st-asc"
> #define ASC_SERIAL_NAME "ttyAS"
> @@ -38,6 +39,7 @@
>
> struct asc_port {
> struct uart_port port;
> + struct gpio_desc *rts;
> struct clk *clk;
> unsigned int hw_flow_control:1;
> unsigned int force_m1:1;
> @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
>
> static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> {
> + struct asc_port *ascport = to_asc_port(port);
> +
> /*
> * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> * We use ASC's hardware for CTS/RTS, so don't need any for that.
> * Some boards have DTR and DCD implemented using PIO pins,
> * code to do this should be hooked in here.
> */
> +
> + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
> }
>
> static unsigned int asc_get_mctrl(struct uart_port *port)
> @@ -731,12 +737,20 @@ MODULE_DEVICE_TABLE(of, asc_match);
> static int asc_serial_probe(struct platform_device *pdev)
> {
> int ret;
> + struct device_node *np = pdev->dev.of_node;
> struct asc_port *ascport;
> + struct gpio_desc *gpiod;
>
> ascport = asc_of_get_asc_port(pdev);
> if (!ascport)
> return -ENODEV;
>
> + gpiod = devm_get_gpiod_from_child(&pdev->dev, "rts", &np->fwnode);
> + if (!IS_ERR(gpiod)) {
> + gpiod_direction_output(gpiod, 0);
> + ascport->rts = gpiod;
> + }
> +
> ret = asc_init_port(ascport, pdev);
> if (ret)
> return ret;
>
^ permalink raw reply [flat|nested] 20+ messages in thread* [PATCH 2/3] serial: st-asc: Provide RTS functionality
@ 2016-12-05 14:11 ` Patrice Chotard
0 siblings, 0 replies; 20+ messages in thread
From: Patrice Chotard @ 2016-12-05 14:11 UTC (permalink / raw)
To: linux-arm-kernel
Hi Lee
On 12/02/2016 03:11 PM, Lee Jones wrote:
> Until this point, it has not been possible for serial applications
> to toggle the UART RTS line. This can be useful with certain
> configurations. For example, when using a Mezzanine on a Linaro
> 96board, RTS line is used to take the the on-board microcontroller
typo "the the on"
> in and out of reset.
>
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
> drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> index 379e5bd..ce46898 100644
> --- a/drivers/tty/serial/st-asc.c
> +++ b/drivers/tty/serial/st-asc.c
> @@ -30,6 +30,7 @@
> #include <linux/of_platform.h>
> #include <linux/serial_core.h>
> #include <linux/clk.h>
> +#include <linux/gpio/consumer.h>
>
> #define DRIVER_NAME "st-asc"
> #define ASC_SERIAL_NAME "ttyAS"
> @@ -38,6 +39,7 @@
>
> struct asc_port {
> struct uart_port port;
> + struct gpio_desc *rts;
> struct clk *clk;
> unsigned int hw_flow_control:1;
> unsigned int force_m1:1;
> @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
>
> static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> {
> + struct asc_port *ascport = to_asc_port(port);
> +
> /*
> * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> * We use ASC's hardware for CTS/RTS, so don't need any for that.
> * Some boards have DTR and DCD implemented using PIO pins,
> * code to do this should be hooked in here.
> */
> +
> + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
> }
>
> static unsigned int asc_get_mctrl(struct uart_port *port)
> @@ -731,12 +737,20 @@ MODULE_DEVICE_TABLE(of, asc_match);
> static int asc_serial_probe(struct platform_device *pdev)
> {
> int ret;
> + struct device_node *np = pdev->dev.of_node;
> struct asc_port *ascport;
> + struct gpio_desc *gpiod;
>
> ascport = asc_of_get_asc_port(pdev);
> if (!ascport)
> return -ENODEV;
>
> + gpiod = devm_get_gpiod_from_child(&pdev->dev, "rts", &np->fwnode);
> + if (!IS_ERR(gpiod)) {
> + gpiod_direction_output(gpiod, 0);
> + ascport->rts = gpiod;
> + }
> +
> ret = asc_init_port(ascport, pdev);
> if (ret)
> return ret;
>
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [STLinux Kernel] [PATCH 2/3] serial: st-asc: Provide RTS functionality
2016-12-05 14:11 ` Patrice Chotard
@ 2016-12-06 12:31 ` Peter Griffin
-1 siblings, 0 replies; 20+ messages in thread
From: Peter Griffin @ 2016-12-06 12:31 UTC (permalink / raw)
To: Patrice Chotard
Cc: Lee Jones, gregkh, jslaby, linux-serial, linux-kernel,
linux-arm-kernel, kernel
Hi Lee,
On Mon, 05 Dec 2016, Patrice Chotard wrote:
> Hi Lee
>
> On 12/02/2016 03:11 PM, Lee Jones wrote:
> > Until this point, it has not been possible for serial applications
> > to toggle the UART RTS line. This can be useful with certain
> > configurations. For example, when using a Mezzanine on a Linaro
> > 96board, RTS line is used to take the the on-board microcontroller
>
> typo "the the on"
>
> > in and out of reset.
> >
> > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > ---
> > drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> > index 379e5bd..ce46898 100644
> > --- a/drivers/tty/serial/st-asc.c
> > +++ b/drivers/tty/serial/st-asc.c
> > @@ -30,6 +30,7 @@
> > #include <linux/of_platform.h>
> > #include <linux/serial_core.h>
> > #include <linux/clk.h>
> > +#include <linux/gpio/consumer.h>
> >
> > #define DRIVER_NAME "st-asc"
> > #define ASC_SERIAL_NAME "ttyAS"
> > @@ -38,6 +39,7 @@
> >
> > struct asc_port {
> > struct uart_port port;
> > + struct gpio_desc *rts;
> > struct clk *clk;
> > unsigned int hw_flow_control:1;
> > unsigned int force_m1:1;
> > @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
> >
> > static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> > {
> > + struct asc_port *ascport = to_asc_port(port);
> > +
> > /*
> > * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> > * We use ASC's hardware for CTS/RTS, so don't need any for that.
> > * Some boards have DTR and DCD implemented using PIO pins,
> > * code to do this should be hooked in here.
> > */
> > +
> > + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
This now puts the code and the comment above out of sync with each
other.
However just checking the stih410 datasheet and I don't think this patch
to control RTS via a GPIO is required anyway.
The correct way of handling this is to add UART10_RTS and UART10_CTS pins
to the pinctrl_serial0 group so they are properly configured for their cts/rts
alternate function. Once the pins are correctly configured, the IP block should
control the signals correctly like the comment says.
regards,
Peter.
^ permalink raw reply [flat|nested] 20+ messages in thread* [STLinux Kernel] [PATCH 2/3] serial: st-asc: Provide RTS functionality
@ 2016-12-06 12:31 ` Peter Griffin
0 siblings, 0 replies; 20+ messages in thread
From: Peter Griffin @ 2016-12-06 12:31 UTC (permalink / raw)
To: linux-arm-kernel
Hi Lee,
On Mon, 05 Dec 2016, Patrice Chotard wrote:
> Hi Lee
>
> On 12/02/2016 03:11 PM, Lee Jones wrote:
> > Until this point, it has not been possible for serial applications
> > to toggle the UART RTS line. This can be useful with certain
> > configurations. For example, when using a Mezzanine on a Linaro
> > 96board, RTS line is used to take the the on-board microcontroller
>
> typo "the the on"
>
> > in and out of reset.
> >
> > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > ---
> > drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> > index 379e5bd..ce46898 100644
> > --- a/drivers/tty/serial/st-asc.c
> > +++ b/drivers/tty/serial/st-asc.c
> > @@ -30,6 +30,7 @@
> > #include <linux/of_platform.h>
> > #include <linux/serial_core.h>
> > #include <linux/clk.h>
> > +#include <linux/gpio/consumer.h>
> >
> > #define DRIVER_NAME "st-asc"
> > #define ASC_SERIAL_NAME "ttyAS"
> > @@ -38,6 +39,7 @@
> >
> > struct asc_port {
> > struct uart_port port;
> > + struct gpio_desc *rts;
> > struct clk *clk;
> > unsigned int hw_flow_control:1;
> > unsigned int force_m1:1;
> > @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
> >
> > static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> > {
> > + struct asc_port *ascport = to_asc_port(port);
> > +
> > /*
> > * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> > * We use ASC's hardware for CTS/RTS, so don't need any for that.
> > * Some boards have DTR and DCD implemented using PIO pins,
> > * code to do this should be hooked in here.
> > */
> > +
> > + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
This now puts the code and the comment above out of sync with each
other.
However just checking the stih410 datasheet and I don't think this patch
to control RTS via a GPIO is required anyway.
The correct way of handling this is to add UART10_RTS and UART10_CTS pins
to the pinctrl_serial0 group so they are properly configured for their cts/rts
alternate function. Once the pins are correctly configured, the IP block should
control the signals correctly like the comment says.
regards,
Peter.
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [STLinux Kernel] [PATCH 2/3] serial: st-asc: Provide RTS functionality
2016-12-06 12:31 ` Peter Griffin
@ 2016-12-06 12:45 ` Lee Jones
-1 siblings, 0 replies; 20+ messages in thread
From: Lee Jones @ 2016-12-06 12:45 UTC (permalink / raw)
To: Peter Griffin
Cc: Patrice Chotard, gregkh, jslaby, linux-serial, linux-kernel,
linux-arm-kernel, kernel
On Tue, 06 Dec 2016, Peter Griffin wrote:
> On Mon, 05 Dec 2016, Patrice Chotard wrote:
> > On 12/02/2016 03:11 PM, Lee Jones wrote:
> > > Until this point, it has not been possible for serial applications
> > > to toggle the UART RTS line. This can be useful with certain
> > > configurations. For example, when using a Mezzanine on a Linaro
> > > 96board, RTS line is used to take the the on-board microcontroller
> >
> > typo "the the on"
> >
> > > in and out of reset.
> > >
> > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > > ---
> > > drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> > > 1 file changed, 14 insertions(+)
> > >
> > > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> > > index 379e5bd..ce46898 100644
> > > --- a/drivers/tty/serial/st-asc.c
> > > +++ b/drivers/tty/serial/st-asc.c
> > > @@ -30,6 +30,7 @@
> > > #include <linux/of_platform.h>
> > > #include <linux/serial_core.h>
> > > #include <linux/clk.h>
> > > +#include <linux/gpio/consumer.h>
> > >
> > > #define DRIVER_NAME "st-asc"
> > > #define ASC_SERIAL_NAME "ttyAS"
> > > @@ -38,6 +39,7 @@
> > >
> > > struct asc_port {
> > > struct uart_port port;
> > > + struct gpio_desc *rts;
> > > struct clk *clk;
> > > unsigned int hw_flow_control:1;
> > > unsigned int force_m1:1;
> > > @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
> > >
> > > static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> > > {
> > > + struct asc_port *ascport = to_asc_port(port);
> > > +
> > > /*
> > > * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> > > * We use ASC's hardware for CTS/RTS, so don't need any for that.
> > > * Some boards have DTR and DCD implemented using PIO pins,
> > > * code to do this should be hooked in here.
> > > */
> > > +
> > > + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
>
> This now puts the code and the comment above out of sync with each
> other.
>
> However just checking the stih410 datasheet and I don't think this patch
> to control RTS via a GPIO is required anyway.
>
> The correct way of handling this is to add UART10_RTS and UART10_CTS pins
> to the pinctrl_serial0 group so they are properly configured for their cts/rts
> alternate function. Once the pins are correctly configured, the IP block should
> control the signals correctly like the comment says.
That was the first thing I tried. It didn't work.
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 20+ messages in thread* [STLinux Kernel] [PATCH 2/3] serial: st-asc: Provide RTS functionality
@ 2016-12-06 12:45 ` Lee Jones
0 siblings, 0 replies; 20+ messages in thread
From: Lee Jones @ 2016-12-06 12:45 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 06 Dec 2016, Peter Griffin wrote:
> On Mon, 05 Dec 2016, Patrice Chotard wrote:
> > On 12/02/2016 03:11 PM, Lee Jones wrote:
> > > Until this point, it has not been possible for serial applications
> > > to toggle the UART RTS line. This can be useful with certain
> > > configurations. For example, when using a Mezzanine on a Linaro
> > > 96board, RTS line is used to take the the on-board microcontroller
> >
> > typo "the the on"
> >
> > > in and out of reset.
> > >
> > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > > ---
> > > drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> > > 1 file changed, 14 insertions(+)
> > >
> > > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> > > index 379e5bd..ce46898 100644
> > > --- a/drivers/tty/serial/st-asc.c
> > > +++ b/drivers/tty/serial/st-asc.c
> > > @@ -30,6 +30,7 @@
> > > #include <linux/of_platform.h>
> > > #include <linux/serial_core.h>
> > > #include <linux/clk.h>
> > > +#include <linux/gpio/consumer.h>
> > >
> > > #define DRIVER_NAME "st-asc"
> > > #define ASC_SERIAL_NAME "ttyAS"
> > > @@ -38,6 +39,7 @@
> > >
> > > struct asc_port {
> > > struct uart_port port;
> > > + struct gpio_desc *rts;
> > > struct clk *clk;
> > > unsigned int hw_flow_control:1;
> > > unsigned int force_m1:1;
> > > @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
> > >
> > > static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> > > {
> > > + struct asc_port *ascport = to_asc_port(port);
> > > +
> > > /*
> > > * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> > > * We use ASC's hardware for CTS/RTS, so don't need any for that.
> > > * Some boards have DTR and DCD implemented using PIO pins,
> > > * code to do this should be hooked in here.
> > > */
> > > +
> > > + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
>
> This now puts the code and the comment above out of sync with each
> other.
>
> However just checking the stih410 datasheet and I don't think this patch
> to control RTS via a GPIO is required anyway.
>
> The correct way of handling this is to add UART10_RTS and UART10_CTS pins
> to the pinctrl_serial0 group so they are properly configured for their cts/rts
> alternate function. Once the pins are correctly configured, the IP block should
> control the signals correctly like the comment says.
That was the first thing I tried. It didn't work.
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [STLinux Kernel] [PATCH 2/3] serial: st-asc: Provide RTS functionality
2016-12-06 12:45 ` Lee Jones
@ 2016-12-06 12:48 ` Lee Jones
-1 siblings, 0 replies; 20+ messages in thread
From: Lee Jones @ 2016-12-06 12:48 UTC (permalink / raw)
To: Peter Griffin
Cc: Patrice Chotard, gregkh, jslaby, linux-serial, linux-kernel,
linux-arm-kernel, kernel
On Tue, 06 Dec 2016, Lee Jones wrote:
> On Tue, 06 Dec 2016, Peter Griffin wrote:
> > On Mon, 05 Dec 2016, Patrice Chotard wrote:
> > > On 12/02/2016 03:11 PM, Lee Jones wrote:
> > > > Until this point, it has not been possible for serial applications
> > > > to toggle the UART RTS line. This can be useful with certain
> > > > configurations. For example, when using a Mezzanine on a Linaro
> > > > 96board, RTS line is used to take the the on-board microcontroller
> > >
> > > typo "the the on"
> > >
> > > > in and out of reset.
> > > >
> > > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > > > ---
> > > > drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> > > > 1 file changed, 14 insertions(+)
> > > >
> > > > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> > > > index 379e5bd..ce46898 100644
> > > > --- a/drivers/tty/serial/st-asc.c
> > > > +++ b/drivers/tty/serial/st-asc.c
> > > > @@ -30,6 +30,7 @@
> > > > #include <linux/of_platform.h>
> > > > #include <linux/serial_core.h>
> > > > #include <linux/clk.h>
> > > > +#include <linux/gpio/consumer.h>
> > > >
> > > > #define DRIVER_NAME "st-asc"
> > > > #define ASC_SERIAL_NAME "ttyAS"
> > > > @@ -38,6 +39,7 @@
> > > >
> > > > struct asc_port {
> > > > struct uart_port port;
> > > > + struct gpio_desc *rts;
> > > > struct clk *clk;
> > > > unsigned int hw_flow_control:1;
> > > > unsigned int force_m1:1;
> > > > @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
> > > >
> > > > static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> > > > {
> > > > + struct asc_port *ascport = to_asc_port(port);
> > > > +
> > > > /*
> > > > * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> > > > * We use ASC's hardware for CTS/RTS, so don't need any for that.
> > > > * Some boards have DTR and DCD implemented using PIO pins,
> > > > * code to do this should be hooked in here.
> > > > */
> > > > +
> > > > + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
> >
> > This now puts the code and the comment above out of sync with each
> > other.
> >
> > However just checking the stih410 datasheet and I don't think this patch
> > to control RTS via a GPIO is required anyway.
> >
> > The correct way of handling this is to add UART10_RTS and UART10_CTS pins
> > to the pinctrl_serial0 group so they are properly configured for their cts/rts
> > alternate function. Once the pins are correctly configured, the IP block should
> > control the signals correctly like the comment says.
>
> That was the first thing I tried. It didn't work.
cts = <&pio17 2 ALT1 IN>;
rts = <&pio17 3 ALT1 OUT>;
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 20+ messages in thread* [STLinux Kernel] [PATCH 2/3] serial: st-asc: Provide RTS functionality
@ 2016-12-06 12:48 ` Lee Jones
0 siblings, 0 replies; 20+ messages in thread
From: Lee Jones @ 2016-12-06 12:48 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 06 Dec 2016, Lee Jones wrote:
> On Tue, 06 Dec 2016, Peter Griffin wrote:
> > On Mon, 05 Dec 2016, Patrice Chotard wrote:
> > > On 12/02/2016 03:11 PM, Lee Jones wrote:
> > > > Until this point, it has not been possible for serial applications
> > > > to toggle the UART RTS line. This can be useful with certain
> > > > configurations. For example, when using a Mezzanine on a Linaro
> > > > 96board, RTS line is used to take the the on-board microcontroller
> > >
> > > typo "the the on"
> > >
> > > > in and out of reset.
> > > >
> > > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > > > ---
> > > > drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> > > > 1 file changed, 14 insertions(+)
> > > >
> > > > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> > > > index 379e5bd..ce46898 100644
> > > > --- a/drivers/tty/serial/st-asc.c
> > > > +++ b/drivers/tty/serial/st-asc.c
> > > > @@ -30,6 +30,7 @@
> > > > #include <linux/of_platform.h>
> > > > #include <linux/serial_core.h>
> > > > #include <linux/clk.h>
> > > > +#include <linux/gpio/consumer.h>
> > > >
> > > > #define DRIVER_NAME "st-asc"
> > > > #define ASC_SERIAL_NAME "ttyAS"
> > > > @@ -38,6 +39,7 @@
> > > >
> > > > struct asc_port {
> > > > struct uart_port port;
> > > > + struct gpio_desc *rts;
> > > > struct clk *clk;
> > > > unsigned int hw_flow_control:1;
> > > > unsigned int force_m1:1;
> > > > @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
> > > >
> > > > static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> > > > {
> > > > + struct asc_port *ascport = to_asc_port(port);
> > > > +
> > > > /*
> > > > * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> > > > * We use ASC's hardware for CTS/RTS, so don't need any for that.
> > > > * Some boards have DTR and DCD implemented using PIO pins,
> > > > * code to do this should be hooked in here.
> > > > */
> > > > +
> > > > + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
> >
> > This now puts the code and the comment above out of sync with each
> > other.
> >
> > However just checking the stih410 datasheet and I don't think this patch
> > to control RTS via a GPIO is required anyway.
> >
> > The correct way of handling this is to add UART10_RTS and UART10_CTS pins
> > to the pinctrl_serial0 group so they are properly configured for their cts/rts
> > alternate function. Once the pins are correctly configured, the IP block should
> > control the signals correctly like the comment says.
>
> That was the first thing I tried. It didn't work.
cts = <&pio17 2 ALT1 IN>;
rts = <&pio17 3 ALT1 OUT>;
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [STLinux Kernel] [PATCH 2/3] serial: st-asc: Provide RTS functionality
2016-12-06 12:48 ` Lee Jones
@ 2016-12-06 13:03 ` Peter Griffin
-1 siblings, 0 replies; 20+ messages in thread
From: Peter Griffin @ 2016-12-06 13:03 UTC (permalink / raw)
To: Lee Jones
Cc: Patrice Chotard, gregkh, jslaby, linux-serial, linux-kernel,
linux-arm-kernel, kernel
Hi Lee,
On Tue, 06 Dec 2016, Lee Jones wrote:
> On Tue, 06 Dec 2016, Lee Jones wrote:
>
> > On Tue, 06 Dec 2016, Peter Griffin wrote:
> > > On Mon, 05 Dec 2016, Patrice Chotard wrote:
> > > > On 12/02/2016 03:11 PM, Lee Jones wrote:
> > > > > Until this point, it has not been possible for serial applications
> > > > > to toggle the UART RTS line. This can be useful with certain
> > > > > configurations. For example, when using a Mezzanine on a Linaro
> > > > > 96board, RTS line is used to take the the on-board microcontroller
> > > >
> > > > typo "the the on"
> > > >
> > > > > in and out of reset.
> > > > >
> > > > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > > > > ---
> > > > > drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> > > > > 1 file changed, 14 insertions(+)
> > > > >
> > > > > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> > > > > index 379e5bd..ce46898 100644
> > > > > --- a/drivers/tty/serial/st-asc.c
> > > > > +++ b/drivers/tty/serial/st-asc.c
> > > > > @@ -30,6 +30,7 @@
> > > > > #include <linux/of_platform.h>
> > > > > #include <linux/serial_core.h>
> > > > > #include <linux/clk.h>
> > > > > +#include <linux/gpio/consumer.h>
> > > > >
> > > > > #define DRIVER_NAME "st-asc"
> > > > > #define ASC_SERIAL_NAME "ttyAS"
> > > > > @@ -38,6 +39,7 @@
> > > > >
> > > > > struct asc_port {
> > > > > struct uart_port port;
> > > > > + struct gpio_desc *rts;
> > > > > struct clk *clk;
> > > > > unsigned int hw_flow_control:1;
> > > > > unsigned int force_m1:1;
> > > > > @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
> > > > >
> > > > > static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> > > > > {
> > > > > + struct asc_port *ascport = to_asc_port(port);
> > > > > +
> > > > > /*
> > > > > * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> > > > > * We use ASC's hardware for CTS/RTS, so don't need any for that.
> > > > > * Some boards have DTR and DCD implemented using PIO pins,
> > > > > * code to do this should be hooked in here.
> > > > > */
> > > > > +
> > > > > + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
> > >
> > > This now puts the code and the comment above out of sync with each
> > > other.
> > >
> > > However just checking the stih410 datasheet and I don't think this patch
> > > to control RTS via a GPIO is required anyway.
> > >
> > > The correct way of handling this is to add UART10_RTS and UART10_CTS pins
> > > to the pinctrl_serial0 group so they are properly configured for their cts/rts
> > > alternate function. Once the pins are correctly configured, the IP block should
> > > control the signals correctly like the comment says.
> >
> > That was the first thing I tried. It didn't work.
>
> cts = <&pio17 2 ALT1 IN>;
> rts = <&pio17 3 ALT1 OUT>;
>
That implies that either some additional configuration of the IP is required in
st-asc to get the IP to control those signals or that there is a bug in the
ST pinctrl driver and the correct settings aren't being applied.
regards,
Peter.
^ permalink raw reply [flat|nested] 20+ messages in thread* [STLinux Kernel] [PATCH 2/3] serial: st-asc: Provide RTS functionality
@ 2016-12-06 13:03 ` Peter Griffin
0 siblings, 0 replies; 20+ messages in thread
From: Peter Griffin @ 2016-12-06 13:03 UTC (permalink / raw)
To: linux-arm-kernel
Hi Lee,
On Tue, 06 Dec 2016, Lee Jones wrote:
> On Tue, 06 Dec 2016, Lee Jones wrote:
>
> > On Tue, 06 Dec 2016, Peter Griffin wrote:
> > > On Mon, 05 Dec 2016, Patrice Chotard wrote:
> > > > On 12/02/2016 03:11 PM, Lee Jones wrote:
> > > > > Until this point, it has not been possible for serial applications
> > > > > to toggle the UART RTS line. This can be useful with certain
> > > > > configurations. For example, when using a Mezzanine on a Linaro
> > > > > 96board, RTS line is used to take the the on-board microcontroller
> > > >
> > > > typo "the the on"
> > > >
> > > > > in and out of reset.
> > > > >
> > > > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > > > > ---
> > > > > drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> > > > > 1 file changed, 14 insertions(+)
> > > > >
> > > > > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> > > > > index 379e5bd..ce46898 100644
> > > > > --- a/drivers/tty/serial/st-asc.c
> > > > > +++ b/drivers/tty/serial/st-asc.c
> > > > > @@ -30,6 +30,7 @@
> > > > > #include <linux/of_platform.h>
> > > > > #include <linux/serial_core.h>
> > > > > #include <linux/clk.h>
> > > > > +#include <linux/gpio/consumer.h>
> > > > >
> > > > > #define DRIVER_NAME "st-asc"
> > > > > #define ASC_SERIAL_NAME "ttyAS"
> > > > > @@ -38,6 +39,7 @@
> > > > >
> > > > > struct asc_port {
> > > > > struct uart_port port;
> > > > > + struct gpio_desc *rts;
> > > > > struct clk *clk;
> > > > > unsigned int hw_flow_control:1;
> > > > > unsigned int force_m1:1;
> > > > > @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port)
> > > > >
> > > > > static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
> > > > > {
> > > > > + struct asc_port *ascport = to_asc_port(port);
> > > > > +
> > > > > /*
> > > > > * This routine is used for seting signals of: DTR, DCD, CTS/RTS
> > > > > * We use ASC's hardware for CTS/RTS, so don't need any for that.
> > > > > * Some boards have DTR and DCD implemented using PIO pins,
> > > > > * code to do this should be hooked in here.
> > > > > */
> > > > > +
> > > > > + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
> > >
> > > This now puts the code and the comment above out of sync with each
> > > other.
> > >
> > > However just checking the stih410 datasheet and I don't think this patch
> > > to control RTS via a GPIO is required anyway.
> > >
> > > The correct way of handling this is to add UART10_RTS and UART10_CTS pins
> > > to the pinctrl_serial0 group so they are properly configured for their cts/rts
> > > alternate function. Once the pins are correctly configured, the IP block should
> > > control the signals correctly like the comment says.
> >
> > That was the first thing I tried. It didn't work.
>
> cts = <&pio17 2 ALT1 IN>;
> rts = <&pio17 3 ALT1 OUT>;
>
That implies that either some additional configuration of the IP is required in
st-asc to get the IP to control those signals or that there is a bug in the
ST pinctrl driver and the correct settings aren't being applied.
regards,
Peter.
^ permalink raw reply [flat|nested] 20+ messages in thread