[PATCH 1/2] net: m_can: tcan4x5x: add required delay after reset

[PATCH 1/2] net: m_can: tcan4x5x: add required delay after reset

[Sean Nyekjaer]

According to section "8.3.8 RST Pin" in the datasheet we are required to
wait >700us after the device is reset.

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
---
 drivers/net/can/m_can/tcan4x5x.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
index 6e37c3fd87af..cb5fdb695ec9 100644
--- a/drivers/net/can/m_can/tcan4x5x.c
+++ b/drivers/net/can/m_can/tcan4x5x.c
@@ -367,6 +367,8 @@ static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
 	if (IS_ERR(tcan4x5x->reset_gpio))
 		tcan4x5x->reset_gpio = NULL;
 
+	usleep_range(700, 1000);
+
 	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
 							      "device-state",
 							      GPIOD_IN);
-- 
2.24.0

[PATCH 2/2] dt-bindings: can: tcan4x5x: reset pin is active high

[Sean Nyekjaer]

Change the reset pin example to active high to be in line with
the datasheet

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
---
 Documentation/devicetree/bindings/net/can/tcan4x5x.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/net/can/tcan4x5x.txt b/Documentation/devicetree/bindings/net/can/tcan4x5x.txt
index 27e1b4cebfbd..e8aa21d9174e 100644
--- a/Documentation/devicetree/bindings/net/can/tcan4x5x.txt
+++ b/Documentation/devicetree/bindings/net/can/tcan4x5x.txt
@@ -36,5 +36,5 @@ tcan4x5x: tcan4x5x@0 {
 		interrupts = <14 GPIO_ACTIVE_LOW>;
 		device-state-gpios = <&gpio3 21 GPIO_ACTIVE_HIGH>;
 		device-wake-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
-		reset-gpios = <&gpio1 27 GPIO_ACTIVE_LOW>;
+		reset-gpios = <&gpio1 27 GPIO_ACTIVE_HIGH>;
 };
-- 
2.24.0

Re: [PATCH 1/2] net: m_can: tcan4x5x: add required delay after reset

[Dan Murphy]

Sean

On 12/6/19 9:29 AM, Sean Nyekjaer wrote:
> According to section "8.3.8 RST Pin" in the datasheet we are required to
> wait >700us after the device is reset.
>
> Signed-off-by: Sean Nyekjaer <sean@geanix.com>
> ---
>   drivers/net/can/m_can/tcan4x5x.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
> index 6e37c3fd87af..cb5fdb695ec9 100644
> --- a/drivers/net/can/m_can/tcan4x5x.c
> +++ b/drivers/net/can/m_can/tcan4x5x.c
> @@ -367,6 +367,8 @@ static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
>   	if (IS_ERR(tcan4x5x->reset_gpio))
>   		tcan4x5x->reset_gpio = NULL;
>   
> +	usleep_range(700, 1000);
> +
>   	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
>   							      "device-state",
>   							      GPIOD_IN);

Acked-by: Dan Murphy <dmurphy@ti.com>

Thanks for the patch.  My data sheet was old and did not have the timing 
diagrams in them.
I downloaded the latest data sheet.

Dan

Re: [PATCH 1/2] net: m_can: tcan4x5x: add required delay after reset

[Dan Murphy]

Sean

On 12/6/19 9:29 AM, Sean Nyekjaer wrote:
> According to section "8.3.8 RST Pin" in the datasheet we are required to
> wait >700us after the device is reset.
>
> Signed-off-by: Sean Nyekjaer <sean@geanix.com>
> ---
>   drivers/net/can/m_can/tcan4x5x.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
> index 6e37c3fd87af..cb5fdb695ec9 100644
> --- a/drivers/net/can/m_can/tcan4x5x.c
> +++ b/drivers/net/can/m_can/tcan4x5x.c
> @@ -367,6 +367,8 @@ static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
>   	if (IS_ERR(tcan4x5x->reset_gpio))
>   		tcan4x5x->reset_gpio = NULL;
>   
> +	usleep_range(700, 1000);
> +
>   	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
>   							      "device-state",
>   							      GPIOD_IN);
Acked-by: Dan Murphy <dmurphy@ti.com>

Re: [PATCH 1/2] net: m_can: tcan4x5x: add required delay after reset

[Marc Kleine-Budde]

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On 12/6/19 4:29 PM, Sean Nyekjaer wrote:
> According to section "8.3.8 RST Pin" in the datasheet we are required to
> wait >700us after the device is reset.
> 
> Signed-off-by: Sean Nyekjaer <sean@geanix.com>

applied both to linux-can.

tnx,
Marc

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