pdp7/PB-MCP2515.dts

## PB-MCP2515.dts
/dts-v1/;
/plugin/;

#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/pinctrl/am33xx.h>
#include <dt-bindings/interrupt-controller/irq.h>

/*

Macchina SPI0 for SWCAN MCP2515 is PocketBeagle SPI1

Macchina PB adapter J3 is PB P1
Macchina PB adapter J2 is next to J3 / PB P1

Macchina PB adapter J4 is PB P2
Macchina PB adapter J1 is next to J4 / PB P2

https://github.com/macchina/pocketbeagle-adapter-hardware/blob/master/SCH-01010%20R0%20SCHEM_RELEASE.PDF
https://github.com/macchina/m2-hardware/tree/master/M2-B
https://github.com/macchina/m2-hardware/blob/master/M2-B/Interface%20Board%20PCB.pdf

M2 J3 is plugs into PB adapter J2, next to PB P1 (which is PB adapter J3)
M2 J4 is plugs into PB adapter J1, next to PB P2 (which is PB adapter J4)

M2 J4.20: SWC nINT <-> P2.8
M2 J3.6 : SWC_nRESET  <-> P2.32
M2 J4.9 : SWC_M0  <-> P2.6
M2 J4.28: SWC_M1  <-> P2.18
M2 J3.30: SWC_CLK  <-> NC
M2 J4.25: SWC_SOF  <-> NC
M2 J4.29: SWC_nRX0BF  <-> NC
M2 J4.30: SWC_nRX1BF  <-> NC

M2 J4.27: SPI0_CLK  <-> PB adapter J2.27: SPI1_CLK
M2 J4.24: SPI0_MISO <-> PB adapter J2.24: SPI1_MISO
M2 J4.26: SPI0_MOSI <-> PB adapter J2.26: SPI1_MOSI
M2 J3.25: SPI0_nCS3 <-> PB adapter J1.25: SPI1_CS

PB adapter J4.25: SPI1_MOSI <-> PB 2.25: SPI1_MOSI
PB adapter J4.27: SPI1_MISO <-> PB 2.27: SPI1_MISO
PB adapter J4.29: SPI1_CLK  <-> PB 2.29: SPI1_CLK
PB adapter J4.31: SPI1_CS   <-> PB 2.31: SPI1_CS

1006 Signals    1006 headers2    1010/PB header
SWC nRESET      J3P6             P2-32
SPI0_nCS3       J3P25            P2-31
SPI0 MISO       J4P24            P2-27
SPI0 MOSI       J4P26            P2-25
SPI0 CLK        J4P27            P2-29
SWC nINT        J4P20            P2-8
SWC nRX0BF      J4P29            NC
SWC nRX1BF      J4P30            NC
SWC SOF         J4P25            NC
SWC CLK         J3P30            NC
SWC M0          J4P9             P2-6
SWC M1          J4P28            P2-18

*/


/ {
        fragment@0 {
                target = <&ocp>;
                __overlay__ {
/*
M2 J4.20: SWC nINT <-> P2.8 <&gpio1 28 0>, needs GPIO input
M2 J3.6 : SWC_nRESET  <-> P2.32 GPIO 112 / PRU0.2, <&gpio3 16 0>, needs GPIO OUTPUT
M2 J4.9 : SWC_M0  <-> P2.6
M2 J4.28: SWC_M1  <-> P2.18
*/
                        P2_08_pinmux { status = "disabled"; };  /* SWC nINT */
                        P2_32_pinmux { status = "disabled"; };  /* SWC nRESET */
                        P2_25_pinmux { status = "disabled"; };  /* MOSI - gpio1_9 */
                        P2_27_pinmux { status = "disabled"; };  /* MISO - gpio1_8 */
                        P2_29_pinmux { status = "disabled"; };  /* CLK - gpio0_7 */
                        P2_31_pinmux { status = "disabled"; };  /* CS - gpio0_19 */
                };
	};

        fragment@1 {
                target = <&spi1>;
                __overlay__ {
                        status = "okay";
                        pinctrl-names = "default";
/*
M2 J4.20: SWC nINT <-> P2.8 <&gpio1 28 0>, needs GPIO input
M2 J3.6 : SWC_nRESET  <-> P2.32 GPIO 112 / PRU0.2, <&gpio3 16 0>, needs GPIO OUTPUT
M2 J4.9 : SWC_M0  <-> P2.6 GPIO 57, needs GPIO OUTPUT
M2 J4.28: SWC_M1  <-> P2.18 GPIO 47, needs GPIO OUTPUT
*/
                        pinctrl-0 = <
                                /* connected to MCP2515 pin 19 _RESET
                                   hopefully pullup will enable the chip */
                                &P2_32_gpio_pu_pin
                                /* SWC nINT */
                                /* &P2_08_gpio_input_pin is not mode 0x37, so wrong? */
                                &P2_08_default_pin /* this should be mode 0x37 */
                                /* SPI1 */
                                &P2_31_spi_cs_pin
                                &P2_29_spi_sclk_pin
                                &P2_27_spi_pin
                                &P2_25_spi_pin
                        >;

                        channel@0{ status = "disabled"; };
                        channel@1{ status = "disabled"; };
                };
        };


        fragment@2 {
		target = <&am33xx_pinmux>;
		__overlay__ {
/*
this was originally for BeagleBone Black and used P8.06

from http://exploringbeaglebone.com/wp-content/uploads/resources/BBBP8Header.pdf
P8_06 3 0x80c/00c 35 GPIO1_3 gpio1[3]

pinctrl-single,pins = < 0x00c 0x37 >;

#0x37 : PIN_OUTPUT_PULLUP | INPUT_EN | MUX_MODE7


for PocketBeagle, Macchina puts nINT on P2.08 (ZCZ ball U18) gpio1_28
P2_08_default_pin: pinmux_P2_08_default_pin { pinctrl-single,pins = <
AM33XX_IOPAD(0x0878, PIN_OUTPUT_PULLUP | INPUT_EN | MUX_MODE7) >; }; gpmc_be1n.gpio1_28

where 0x0878 = PB_P2_08
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/pinctrl/omap.h#n57
https://github.com/beagleboard/bb.org-overlays/blob/master/tools/pinmux-generator/PocketBeagle.dts#L465-L467
https://github.com/beagleboard/bb.org-overlays/blob/master/tools/pinmux-generator/lib/pinmux.sh#L631
so let's try giving pincntrl-single 0x087 which should be the offset from the 0x0800 base
*/
			mcp2515_int: mcp2515_int {
				pinctrl-single,pins = < 0x087 0x37 >;
			};
		};
	};

	fragment@3 {
		target-path = "/";
		__overlay__ {
			mcp2515_clock: mcp2515_clock {
				compatible = "fixed-clock";
				#clock-cells = <0>;
				clock-frequency = <8000000>;
			};
		};
	};

	fragment@4 {
		target = <&spi1>;
		__overlay__ {
			#address-cells = <1>;
			#size-cells = <0>;
			can0: mcp2515@0 {
				status = "okay";
				reg = <0>;
				compatible = "microchip,mcp2515";
				pinctrl-names = "default";
				pinctrl-0 = <&mcp2515_int>;
				spi-max-frequency = <10000000>;
				interrupt-parent = <&gpio1>;
				interrupts = <3 2>;
				clocks = <&mcp2515_clock>;

				mcp251x,oscillator-frequency = <8000000>;
				mcp251x,irq-gpios = <&gpio1 28 0>;
				mcp251x,stay-awake = <1>;
				mcp251x,enable-clkout = <1>;
			};
		};
	};

	__overrides__ {
		oscillator = <&mcp2515_clock>,"clock-frequency:0";
		spimaxfrequency = <&can0>,"spi-max-frequency:0";
		interrupt = <&mcp2515_int>,"pinctrl-single,pins:0",<&can0>,"interrupts:0";
	};

};
	/dts-v1/;
	/plugin/;

	#include <dt-bindings/gpio/gpio.h>
	#include <dt-bindings/pinctrl/am33xx.h>
	#include <dt-bindings/interrupt-controller/irq.h>

	/*

	Macchina SPI0 for SWCAN MCP2515 is PocketBeagle SPI1

	Macchina PB adapter J3 is PB P1
	Macchina PB adapter J2 is next to J3 / PB P1

	Macchina PB adapter J4 is PB P2
	Macchina PB adapter J1 is next to J4 / PB P2

	https://github.com/macchina/pocketbeagle-adapter-hardware/blob/master/SCH-01010%20R0%20SCHEM_RELEASE.PDF
	https://github.com/macchina/m2-hardware/tree/master/M2-B
	https://github.com/macchina/m2-hardware/blob/master/M2-B/Interface%20Board%20PCB.pdf

	M2 J3 is plugs into PB adapter J2, next to PB P1 (which is PB adapter J3)
	M2 J4 is plugs into PB adapter J1, next to PB P2 (which is PB adapter J4)

	M2 J4.20: SWC nINT <-> P2.8
	M2 J3.6 : SWC_nRESET <-> P2.32
	M2 J4.9 : SWC_M0 <-> P2.6
	M2 J4.28: SWC_M1 <-> P2.18
	M2 J3.30: SWC_CLK <-> NC
	M2 J4.25: SWC_SOF <-> NC
	M2 J4.29: SWC_nRX0BF <-> NC
	M2 J4.30: SWC_nRX1BF <-> NC

	M2 J4.27: SPI0_CLK <-> PB adapter J2.27: SPI1_CLK
	M2 J4.24: SPI0_MISO <-> PB adapter J2.24: SPI1_MISO
	M2 J4.26: SPI0_MOSI <-> PB adapter J2.26: SPI1_MOSI
	M2 J3.25: SPI0_nCS3 <-> PB adapter J1.25: SPI1_CS

	PB adapter J4.25: SPI1_MOSI <-> PB 2.25: SPI1_MOSI
	PB adapter J4.27: SPI1_MISO <-> PB 2.27: SPI1_MISO
	PB adapter J4.29: SPI1_CLK <-> PB 2.29: SPI1_CLK
	PB adapter J4.31: SPI1_CS <-> PB 2.31: SPI1_CS

	1006 Signals 1006 headers2 1010/PB header
	SWC nRESET J3P6 P2-32
	SPI0_nCS3 J3P25 P2-31
	SPI0 MISO J4P24 P2-27
	SPI0 MOSI J4P26 P2-25
	SPI0 CLK J4P27 P2-29
	SWC nINT J4P20 P2-8
	SWC nRX0BF J4P29 NC
	SWC nRX1BF J4P30 NC
	SWC SOF J4P25 NC
	SWC CLK J3P30 NC
	SWC M0 J4P9 P2-6
	SWC M1 J4P28 P2-18

	*/


	/ {
	fragment@0 {
	target = <&ocp>;
	__overlay__ {
	/*
	M2 J4.20: SWC nINT <-> P2.8 <&gpio1 28 0>, needs GPIO input
	M2 J3.6 : SWC_nRESET <-> P2.32 GPIO 112 / PRU0.2, <&gpio3 16 0>, needs GPIO OUTPUT
	M2 J4.9 : SWC_M0 <-> P2.6
	M2 J4.28: SWC_M1 <-> P2.18
	*/
	P2_08_pinmux { status = "disabled"; }; /* SWC nINT */
	P2_32_pinmux { status = "disabled"; }; /* SWC nRESET */
	P2_25_pinmux { status = "disabled"; }; /* MOSI - gpio1_9 */
	P2_27_pinmux { status = "disabled"; }; /* MISO - gpio1_8 */
	P2_29_pinmux { status = "disabled"; }; /* CLK - gpio0_7 */
	P2_31_pinmux { status = "disabled"; }; /* CS - gpio0_19 */
	};
	};

	fragment@1 {
	target = <&spi1>;
	__overlay__ {
	status = "okay";
	pinctrl-names = "default";
	/*
	M2 J4.20: SWC nINT <-> P2.8 <&gpio1 28 0>, needs GPIO input
	M2 J3.6 : SWC_nRESET <-> P2.32 GPIO 112 / PRU0.2, <&gpio3 16 0>, needs GPIO OUTPUT
	M2 J4.9 : SWC_M0 <-> P2.6 GPIO 57, needs GPIO OUTPUT
	M2 J4.28: SWC_M1 <-> P2.18 GPIO 47, needs GPIO OUTPUT
	*/
	pinctrl-0 = <
	/* connected to MCP2515 pin 19 _RESET
	hopefully pullup will enable the chip */
	&P2_32_gpio_pu_pin
	/* SWC nINT */
	/* &P2_08_gpio_input_pin is not mode 0x37, so wrong? */
	&P2_08_default_pin /* this should be mode 0x37 */
	/* SPI1 */
	&P2_31_spi_cs_pin
	&P2_29_spi_sclk_pin
	&P2_27_spi_pin
	&P2_25_spi_pin
	>;

	channel@0{ status = "disabled"; };
	channel@1{ status = "disabled"; };
	};
	};


	fragment@2 {
	target = <&am33xx_pinmux>;
	__overlay__ {
	/*
	this was originally for BeagleBone Black and used P8.06

	from http://exploringbeaglebone.com/wp-content/uploads/resources/BBBP8Header.pdf
	P8_06 3 0x80c/00c 35 GPIO1_3 gpio1[3]

	pinctrl-single,pins = < 0x00c 0x37 >;

	#0x37 : PIN_OUTPUT_PULLUP \| INPUT_EN \| MUX_MODE7



	for PocketBeagle, Macchina puts nINT on P2.08 (ZCZ ball U18) gpio1_28
	P2_08_default_pin: pinmux_P2_08_default_pin { pinctrl-single,pins = <
	AM33XX_IOPAD(0x0878, PIN_OUTPUT_PULLUP \| INPUT_EN \| MUX_MODE7) >; }; gpmc_be1n.gpio1_28

	where 0x0878 = PB_P2_08
	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/pinctrl/omap.h#n57
	https://github.com/beagleboard/bb.org-overlays/blob/master/tools/pinmux-generator/PocketBeagle.dts#L465-L467
	https://github.com/beagleboard/bb.org-overlays/blob/master/tools/pinmux-generator/lib/pinmux.sh#L631
	so let's try giving pincntrl-single 0x087 which should be the offset from the 0x0800 base
	*/
	mcp2515_int: mcp2515_int {
	pinctrl-single,pins = < 0x087 0x37 >;
	};
	};
	};

	fragment@3 {
	target-path = "/";
	__overlay__ {
	mcp2515_clock: mcp2515_clock {
	compatible = "fixed-clock";
	#clock-cells = <0>;
	clock-frequency = <8000000>;
	};
	};
	};

	fragment@4 {
	target = <&spi1>;
	__overlay__ {
	#address-cells = <1>;
	#size-cells = <0>;
	can0: mcp2515@0 {
	status = "okay";
	reg = <0>;
	compatible = "microchip,mcp2515";
	pinctrl-names = "default";
	pinctrl-0 = <&mcp2515_int>;
	spi-max-frequency = <10000000>;
	interrupt-parent = <&gpio1>;
	interrupts = <3 2>;
	clocks = <&mcp2515_clock>;

	mcp251x,oscillator-frequency = <8000000>;
	mcp251x,irq-gpios = <&gpio1 28 0>;
	mcp251x,stay-awake = <1>;
	mcp251x,enable-clkout = <1>;
	};
	};
	};

	__overrides__ {
	oscillator = <&mcp2515_clock>,"clock-frequency:0";
	spimaxfrequency = <&can0>,"spi-max-frequency:0";
	interrupt = <&mcp2515_int>,"pinctrl-single,pins:0",<&can0>,"interrupts:0";
	};

	};