[PATCH 1/2] dt-bindings: can: fsl,flexcan.yaml: introduce the stb-gpios property

[PATCH 1/2] dt-bindings: can: fsl,flexcan.yaml: introduce the stb-gpios property

[Fabio Estevam]

It is very common to have an STB pin in CAN transceivers, which allows
putting the transceiver in standby or normal operation mode.

Add a new optional 'stb-gpios' property to describe this.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
 Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
index 0d2df30f19db..64f904c4b3d5 100644
--- a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
+++ b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
@@ -66,6 +66,9 @@ properties:
   xceiver-supply:
     description: Regulator that powers the CAN transceiver.
 
+  stb-gpios:
+    description: GPIO that controls the STB CAN transceiver pin.
+
   big-endian:
     $ref: /schemas/types.yaml#/definitions/flag
     description: |
-- 
2.17.1

[PATCH 2/2] can: flexcan: allow the control of the STB CAN transceiver pin

[Fabio Estevam]

It is very common to have an STB pin in CAN transceivers, which allows
putting the transceiver in standby or normal operation mode.

Add support for handling the STB pin.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
 drivers/net/can/flexcan.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 038fe1036df2..094050b4b461 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -17,6 +17,7 @@
 #include <linux/can/rx-offload.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/mfd/syscon.h>
@@ -358,6 +359,8 @@ struct flexcan_priv {
 	struct regulator *reg_xceiver;
 	struct flexcan_stop_mode stm;
 
+	struct gpio_desc *stb;
+
 	/* Read and Write APIs */
 	u32 (*read)(void __iomem *addr);
 	void (*write)(u32 val, void __iomem *addr);
@@ -617,6 +620,8 @@ static void flexcan_clks_disable(const struct flexcan_priv *priv)
 
 static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
 {
+	gpiod_set_value_cansleep(priv->stb, 0);
+
 	if (!priv->reg_xceiver)
 		return 0;
 
@@ -625,6 +630,8 @@ static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
 
 static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
 {
+	gpiod_set_value_cansleep(priv->stb, 1);
+
 	if (!priv->reg_xceiver)
 		return 0;
 
@@ -2044,6 +2051,10 @@ static int flexcan_probe(struct platform_device *pdev)
 		priv->can.bittiming_const = &flexcan_bittiming_const;
 	}
 
+	priv->stb = devm_gpiod_get_optional(&pdev->dev, "stb", GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->stb))
+		return PTR_ERR(priv->stb);
+
 	pm_runtime_get_noresume(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
-- 
2.17.1

Re: [PATCH 1/2] dt-bindings: can: fsl,flexcan.yaml: introduce the stb-gpios property

[Rob Herring]

On Thu, Jan 07, 2021 at 05:59:14PM -0300, Fabio Estevam wrote:
> It is very common to have an STB pin in CAN transceivers, which allows
> putting the transceiver in standby or normal operation mode.
> 
> Add a new optional 'stb-gpios' property to describe this.
> 
> Signed-off-by: Fabio Estevam <festevam@gmail.com>
> ---
>  Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> index 0d2df30f19db..64f904c4b3d5 100644
> --- a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> +++ b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> @@ -66,6 +66,9 @@ properties:
>    xceiver-supply:
>      description: Regulator that powers the CAN transceiver.
>  
> +  stb-gpios:
> +    description: GPIO that controls the STB CAN transceiver pin.

maxItems: 1

> +
>    big-endian:
>      $ref: /schemas/types.yaml#/definitions/flag
>      description: |
> -- 
> 2.17.1
>