[PATCH 0/2] arm64: dts: renesas: r8a779g0/white-hawk: Add CAN-FD support

[PATCH 0/2] arm64: dts: renesas: r8a779g0/white-hawk: Add CAN-FD support

[Geert Uytterhoeven]

	Hi all,

This patch series enables support for the CAN-FD interface on the Renesas
R-Car V4H (R8A779G0) SoC, and for the first two CAN-FD channels on the
Renesas White-Hawk development board.

While R-Car V4H supports 8 CAN-FD channels, and White-Hawk has
transceivers mounted for the first 4 channels, my test results are
similar to what Ulrich Hecht reported for R-Car V3U on the Falcon
development board before, i.e. only channels 0 and 1 work, and thus this
series enables support for these channels only.  Whether this is a
CAN-FD driver issue, a pin control issue, an IP core issue, or an SoC
integration issue is still to be seen...

For testing, this series and its dependencies can be found at [1].

Thanks for your comments!

[1] https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/log/?h=topic/r8a779g0-canfd-v1

Geert Uytterhoeven (2):
  arm64: dts: renesas: r8a779g0: Add CAN-FD node
  arm64: dts: renesas: white-hawk: Add CAN-FD support

 .../boot/dts/renesas/r8a779g0-white-hawk.dts  | 44 ++++++++++++++
 arch/arm64/boot/dts/renesas/r8a779g0.dtsi     | 57 +++++++++++++++++++
 2 files changed, 101 insertions(+)

-- 
2.34.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

[PATCH 1/2] arm64: dts: renesas: r8a779g0: Add CAN-FD node

[Geert Uytterhoeven]

Add device nodes for the CAN-FD interface and the related external CAN
clock on the Renesas R-Car V4H (R8A779G0) SoC.

Based on a patch in the BSP by Kazuya Mizuguch.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Changes compared to the BSP:
  - Add family-specific compatible value,
  - Correct reg size,
  - Add missing interrupt-names.
---
 arch/arm64/boot/dts/renesas/r8a779g0.dtsi | 57 +++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/arch/arm64/boot/dts/renesas/r8a779g0.dtsi b/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
index 83d1666a2ea16de2..d4cc89e49c68d52e 100644
--- a/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
+++ b/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
@@ -14,6 +14,13 @@ / {
 	#address-cells = <2>;
 	#size-cells = <2>;
 
+	/* External CAN clock - to be overridden by boards that provide it */
+	can_clk: can {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <0>;
+	};
+
 	cluster0_opp: opp-table-0 {
 		compatible = "operating-points-v2";
 		opp-shared;
@@ -676,6 +683,56 @@ hscif3: serial@e66a0000 {
 			status = "disabled";
 		};
 
+		canfd: can@e6660000 {
+			compatible = "renesas,r8a779g0-canfd",
+				     "renesas,rcar-gen4-canfd";
+			reg = <0 0xe6660000 0 0x8500>;
+			interrupts = <GIC_SPI 412 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 413 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "ch_int", "g_int";
+			clocks = <&cpg CPG_MOD 328>,
+				 <&cpg CPG_CORE R8A779G0_CLK_CANFD>,
+				 <&can_clk>;
+			clock-names = "fck", "canfd", "can_clk";
+			assigned-clocks = <&cpg CPG_CORE R8A779G0_CLK_CANFD>;
+			assigned-clock-rates = <80000000>;
+			power-domains = <&sysc R8A779G0_PD_ALWAYS_ON>;
+			resets = <&cpg 328>;
+			status = "disabled";
+
+			channel0 {
+				status = "disabled";
+			};
+
+			channel1 {
+				status = "disabled";
+			};
+
+			channel2 {
+				status = "disabled";
+			};
+
+			channel3 {
+				status = "disabled";
+			};
+
+			channel4 {
+				status = "disabled";
+			};
+
+			channel5 {
+				status = "disabled";
+			};
+
+			channel6 {
+				status = "disabled";
+			};
+
+			channel7 {
+				status = "disabled";
+			};
+		};
+
 		avb0: ethernet@e6800000 {
 			compatible = "renesas,etheravb-r8a779g0",
 				     "renesas,etheravb-rcar-gen4";
-- 
2.34.1

[PATCH 2/2] arm64: dts: renesas: white-hawk: Add CAN-FD support

[Geert Uytterhoeven]

Enable confirmed-working CAN-FD channels 0 and 1 on the White-Hawk
development board:
  - Channel 0 uses an NXP TJR1443AT CAN transceiver, which is be enabled
    through a GPIO,
  - Channels 1-7 use Microchip MCP2558FD-H/SN CAN transceivers (not
    mounted for channels 4-7), which do not need explicit description,
    but channels 2-3 do not seem to work.

Inspired by a patch in the BSP by Kazuya Mizuguch.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
This depends on "[PATCH 2/2] phy: phy-can-transceiver: Add support for
NXP TJR1443"
https://lore.kernel.org/all/0bfa1e4c43632e49c9512b4e7daa970545545dcf.1674037830.git.geert+renesas@glider.be

Changed compared to the BSP:
  - Add can_clk,
  - Add missing can_transceiver0,
  - Disable channels 2-7.

Tested using cansend, candump, and canfdtest.

  - Channel 2 does not work: "bus-off" error message.

  - Channel 3 does not work:
      - Using cansend on another interface, and candump on can3 shows
	that nothing is received.
	However, my scope does see the data on the bus, and it is not
	sent repeatedly, hence it must have been acked by the receiver.

      - Using canfdtest on can3 gives:

          can3: Message ID mismatch!
            expected: 0078: [8] 01 02 03 04 05 06 07 08
            received: 0077: [8] 00 01 02 03 04 05 06 07

Note that describing a plain gpio-hog instead of can_transceiver0 is not
sufficient, as the enable signal must not be asserted before
initialization of the CAN-FD controller,
---
 .../boot/dts/renesas/r8a779g0-white-hawk.dts  | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/arch/arm64/boot/dts/renesas/r8a779g0-white-hawk.dts b/arch/arm64/boot/dts/renesas/r8a779g0-white-hawk.dts
index 04a2b6b83e743f32..eff1ef6e2cc83aba 100644
--- a/arch/arm64/boot/dts/renesas/r8a779g0-white-hawk.dts
+++ b/arch/arm64/boot/dts/renesas/r8a779g0-white-hawk.dts
@@ -13,6 +13,33 @@
 / {
 	model = "Renesas White Hawk CPU and Breakout boards based on r8a779g0";
 	compatible = "renesas,white-hawk-breakout", "renesas,white-hawk-cpu", "renesas,r8a779g0";
+
+	can_transceiver0: can-phy0 {
+		compatible = "nxp,tjr1443";
+		#phy-cells = <0>;
+		enable-gpios = <&gpio1 3 GPIO_ACTIVE_HIGH>;
+		max-bitrate = <5000000>;
+	};
+};
+
+&can_clk {
+	clock-frequency = <40000000>;
+};
+
+&canfd {
+	pinctrl-0 = <&canfd0_pins>, <&canfd1_pins>, <&can_clk_pins>;
+	pinctrl-names = "default";
+
+	status = "okay";
+
+	channel0 {
+		status = "okay";
+		phys = <&can_transceiver0>;
+	};
+
+	channel1 {
+		status = "okay";
+	};
 };
 
 &i2c0 {
@@ -23,3 +50,20 @@ eeprom@51 {
 		pagesize = <8>;
 	};
 };
+
+&pfc {
+	can_clk_pins: can-clk {
+		groups = "can_clk";
+		function = "can_clk";
+	};
+
+	canfd0_pins: canfd0 {
+		groups = "canfd0_data";
+		function = "canfd0";
+	};
+
+	canfd1_pins: canfd1 {
+		groups = "canfd1_data";
+		function = "canfd1";
+	};
+};
-- 
2.34.1

Re: [PATCH 2/2] arm64: dts: renesas: white-hawk: Add CAN-FD support

[Sergei Shtylyov]

Hello!

On 1/23/23 10:06 PM, Geert Uytterhoeven wrote:

> Enable confirmed-working CAN-FD channels 0 and 1 on the White-Hawk
> development board:
>   - Channel 0 uses an NXP TJR1443AT CAN transceiver, which is be enabled

   Is be enabled? :-)

>     through a GPIO,
>   - Channels 1-7 use Microchip MCP2558FD-H/SN CAN transceivers (not
>     mounted for channels 4-7), which do not need explicit description,
>     but channels 2-3 do not seem to work.
> 
> Inspired by a patch in the BSP by Kazuya Mizuguch.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[...]

MBR, Sergey