Subject: Re: [PATCH] rcar_can: add device tree support

From: Marc Kleine-Budde <[email-masked]>
Date: Wed, 02 Jul 2014 00:50:45 +0200

On 07/02/2014 12:27 AM, Sergei Shtylyov wrote:
> Add support of the device tree probing for the Renesas R-Car CAN controllers
> documenting the device tree bindings as necessary.

Please put the DT documentation into a separate patch, make it the first
one. When reposting, please put the device tree mailing list on Cc.

> Signed-off-by: Sergei Shtylyov <[email-masked]>
> 
> ---
> The patch is against the Dave Miller's 'net-next.git' repo ('linux-can-next.git'
> repo still doesn't have the R-Car CAN driver for some reason).

Should be fixed now :)

> 
>  Documentation/devicetree/bindings/net/can/rcar_can.txt |   40 +++++++++++++++++
>  drivers/net/can/rcar_can.c                             |   28 +++++++++--
>  2 files changed, 63 insertions(+), 5 deletions(-)
> 
> Index: net-next/Documentation/devicetree/bindings/net/can/rcar_can.txt
> ===================================================================
> --- /dev/null
> +++ net-next/Documentation/devicetree/bindings/net/can/rcar_can.txt
> @@ -0,0 +1,40 @@
> +Renesas R-Car CAN controller Device Tree Bindings
> +-------------------------------------------------
> +
> +Required properties:
> +- compatible: "renesas,can-r8a7778" if CAN controller is a part of R8A7778 SoC.
> +	      "renesas,can-r8a7779" if CAN controller is a part of R8A7779 SoC.
> +	      "renesas,can-r8a7790" if CAN controller is a part of R8A7790 SoC.
> +	      "renesas,can-r8a7791" if CAN controller is a part of R8A7791 SoC.

AFAIK we usually specify the first SoC with this core as the only
compatible.

> +- reg: physical base address and size of the R-Car CAN register map.
> +- interrupts: interrupt specifier for the sole interrupt.
> +- clocks: phandle and clock specifier for the R-Car CAN clock input.
> +- pinctrl-0: pin control group to be used for this controller.
> +- pinctrl-names: must be "default".
> +
> +Optional properties:
> +- clock-select: R-Car CAN Clock Source Select. Valid values are:
> +		<0x0> (default) : Peripheral clock (clkp1)
> +		<0x1> : Peripheral clock (clkp2)
> +		<0x3> : Externally input clock
> +
> +Example
> +-------
> +
> +SoC common .dtsi file:
> +
> +	can0: can@e6e80000 {
> +		compatible = "renesas,can-r8a7791";
> +		reg = <0 0xe6e80000 0 0x1000>;
> +		interrupts = <0 186 IRQ_TYPE_LEVEL_HIGH>;
> +		clocks = <&mstp9_clks R8A7791_CLK_RCAN0>;
> +		status = "disabled";
> +	};
> +
> +Board specific .dts file:
> +
> +&can0 {
> +	pinctrl-0 = <&can0_pins>;
> +	pinctrl-names = "default";
> +	status = "okay";
> +};
> Index: net-next/drivers/net/can/rcar_can.c
> ===================================================================
> --- net-next.orig/drivers/net/can/rcar_can.c
> +++ net-next/drivers/net/can/rcar_can.c
> @@ -20,6 +20,7 @@
>  #include <linux/can/dev.h>
>  #include <linux/clk.h>
>  #include <linux/can/platform/rcar_can.h>
> +#include <linux/of.h>
>  
>  #define RCAR_CAN_DRV_NAME	"rcar_can"
>  
> @@ -722,13 +723,20 @@ static int rcar_can_probe(struct platfor
>  	struct net_device *ndev;
>  	struct resource *mem;
>  	void __iomem *addr;
> +	u32 clock_select = 0;
>  	int err = -ENODEV;
>  	int irq;
>  
> -	pdata = dev_get_platdata(&pdev->dev);
> -	if (!pdata) {
> -		dev_err(&pdev->dev, "No platform data provided!\n");
> -		goto fail;
> +	if (!pdev->dev.of_node) {

nitpick: please make it positive logic.

> +		pdata = dev_get_platdata(&pdev->dev);
> +		if (!pdata) {
> +			dev_err(&pdev->dev, "No platform data provided!\n");
> +			goto fail;
> +		}
> +		clock_select = pdata->clock_select;
> +	} else {
> +		of_property_read_u32(pdev->dev.of_node, "clock-select",
> +				     &clock_select);
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
> @@ -765,7 +773,7 @@ static int rcar_can_probe(struct platfor
>  	ndev->flags |= IFF_ECHO;
>  	priv->ndev = ndev;
>  	priv->regs = addr;
> -	priv->clock_select = pdata->clock_select;
> +	priv->clock_select = clock_select;
>  	priv->can.clock.freq = clk_get_rate(priv->clk);
>  	priv->can.bittiming_const = &rcar_can_bittiming_const;
>  	priv->can.do_set_mode = rcar_can_do_set_mode;
> @@ -858,10 +866,20 @@ static int __maybe_unused rcar_can_resum
>  
>  static SIMPLE_DEV_PM_OPS(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume);
>  
> +static const struct of_device_id rcar_can_of_table[] __maybe_unused = {
> +	{ .compatible = "renesas,can-r8a7778" },
> +	{ .compatible = "renesas,can-r8a7779" },
> +	{ .compatible = "renesas,can-r8a7790" },
> +	{ .compatible = "renesas,can-r8a7791" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, rcar_can_of_table);
> +
>  static struct platform_driver rcar_can_driver = {
>  	.driver = {
>  		.name = RCAR_CAN_DRV_NAME,
>  		.owner = THIS_MODULE,
> +		.of_match_table = of_match_ptr(rcar_can_of_table),
>  		.pm = &rcar_can_pm_ops,
>  	},
>  	.probe = rcar_can_probe,
> 

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |