[PATCH] rcar_can: add device tree support

Add support of the device tree probing for the Renesas R-Car CAN controllers
documenting the device tree bindings as necessary.

Signed-off-by: Sergei Shtylyov <redacted>

---
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).

 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.
+- 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) {
+		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,

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 <redacted>

---
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 :)

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

nitpick: please make it positive logic.

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   |

On Tue, Jul 01, 2014 at 11:50:45PM +0100, Marc Kleine-Budde wrote:

On 07/02/2014 12:27 AM, Sergei Shtylyov wrote:

quoted

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.

quoted

Signed-off-by: Sergei Shtylyov <redacted>

---
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 :)

quoted

 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.

Not quite. While the driver only needs to have support for that and
DTS files should have that string in the compatible list, the other
strings can be present in the binding and earlier in the compatible list
to allow us to distinguish the variants later (without requiring changes
to DTBs).

quoted

+- 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

What's this for, and how does this interact with the single clock listed
above?

THanks,
Mark.

Hello.

On 07/02/2014 02:14 PM, Mark Rutland wrote:

quoted

quoted

Add support of the device tree probing for the Renesas R-Car CAN controllers
documenting the device tree bindings as necessary.

[...]

quoted

quoted

Signed-off-by: Sergei Shtylyov <redacted>

[...]

quoted

quoted

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 @@

[...]

quoted

quoted

+- 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

What's this for, and how does this interact with the single clock listed
above?

    That's supposed to select a source for the CAN bus clock. Looking back at 
the driver, it seems to actually only support the value of 0. That's something 
we haven't given enough attention to clearly... :-/

THanks,
Mark.

WBR, Sergei

Hello.

On 07/02/2014 02:50 AM, Marc Kleine-Budde wrote:

quoted

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

    OK.

one. When reposting, please put the device tree mailing list on Cc.

    It was among the To: recipients in this posting; I'm using 
scripts/get_maintainer.pl to find out the people/lists I should send the 
patches to.

quoted

Signed-off-by: Sergei Shtylyov <redacted>

quoted

---
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 :)

    Indeed, thanks.

quoted

  Documentation/devicetree/bindings/net/can/rcar_can.txt |   40 +++++++++++++++++
  drivers/net/can/rcar_can.c                             |   28 +++++++++--
  2 files changed, 63 insertions(+), 5 deletions(-)

quoted

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.

    The reason we've chosen several SoC specific "compatible" props is that in 
the SH-Mobile community the maintainers want it this way. There's no version 
register in the IP blocks and the SoC manuals we have are not considered 
reliable enough sources of information, so that the compatibility between the 
different SoCs cannot be reliably established...

[...]

quoted

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

[...]

quoted

@@ -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.

    OK, will do.

Marc

WBR, Sergei