/*
 * Copyright (c) 2020 Pete Johanson
 *
 * SPDX-License-Identifier: MIT
 */

#include <dt-bindings/zmk/matrix_transform.h>

/ {
    chosen {
        zephyr,display = &oled;
        zmk,kscan = &kscan0;
        zmk,matrix-transform = &default_transform;
    };

    default_transform: keymap_transform_0 {
        compatible = "zmk,matrix-transform";
        columns = <12>;
        rows = <4>;
// | SW1  | SW2  | SW3  | SW4  | SW5  | SW6  |   | SW6  | SW5  | SW4  | SW3  | SW2  | SW1  |
// | SW7  | SW8  | SW9  | SW10 | SW11 | SW12 |   | SW12 | SW11 | SW10 | SW9  | SW8  | SW7  |
// | SW13 | SW14 | SW15 | SW16 | SW17 | SW18 |   | SW18 | SW17 | SW16 | SW15 | SW14 | SW13 |
//                      | SW19 | SW20 | SW21 |   | SW21 | SW20 | SW19 |
        map = <
RC(0,0) RC(0,1) RC(0,2) RC(0,3) RC(0,4) RC(0,5)  RC(0,6) RC(0,7) RC(0,8) RC(0,9) RC(0,10) RC(0,11)
RC(1,0) RC(1,1) RC(1,2) RC(1,3) RC(1,4) RC(1,5)  RC(1,6) RC(1,7) RC(1,8) RC(1,9) RC(1,10) RC(1,11)
RC(2,0) RC(2,1) RC(2,2) RC(2,3) RC(2,4) RC(2,5)  RC(2,6) RC(2,7) RC(2,8) RC(2,9) RC(2,10) RC(2,11)
                        RC(3,3) RC(3,4) RC(3,5)  RC(3,6) RC(3,7) RC(3,8)
        >;
    };

    five_column_transform: keymap_transform_1 {
        compatible = "zmk,matrix-transform";
        columns = <10>;
        rows = <4>;
// | SW2  | SW3  | SW4  | SW5  | SW6  |   | SW6  | SW5  | SW4  | SW3  | SW2  |
// | SW8  | SW9  | SW10 | SW11 | SW12 |   | SW12 | SW11 | SW10 | SW9  | SW8  |
// | SW14 | SW15 | SW16 | SW17 | SW18 |   | SW18 | SW17 | SW16 | SW15 | SW14 |
//                      | SW19 | SW20 | SW21 |   | SW21 | SW20 | SW19 |
        map = <
RC(0,1) RC(0,2) RC(0,3) RC(0,4) RC(0,5)  RC(0,6) RC(0,7) RC(0,8) RC(0,9) RC(0,10)
RC(1,1) RC(1,2) RC(1,3) RC(1,4) RC(1,5)  RC(1,6) RC(1,7) RC(1,8) RC(1,9) RC(1,10)
RC(2,1) RC(2,2) RC(2,3) RC(2,4) RC(2,5)  RC(2,6) RC(2,7) RC(2,8) RC(2,9) RC(2,10)
                        RC(3,3) RC(3,4) RC(3,5)  RC(3,6) RC(3,7) RC(3,8)
        >;
    };

    kscan0: kscan {
        compatible = "zmk,kscan-gpio-matrix";

        diode-direction = "col2row";
        row-gpios
            = <&pro_micro 4 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
            , <&pro_micro 5 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
            , <&pro_micro 6 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
            , <&pro_micro 7 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
            ;

    };

    // TODO: per-key RGB node(s)?
};

&pro_micro_i2c {
    status = "okay";

    oled: ssd1306@3c {
        compatible = "solomon,ssd1306fb";
        reg = <0x3c>;
        width = <128>;
        height = <32>;
        segment-offset = <0>;
        page-offset = <0>;
        display-offset = <0>;
        multiplex-ratio = <31>;
        segment-remap;
        com-invdir;
        com-sequential;
        prechargep = <0x22>;
    };
};


/*
 * PS/2 Mouse / Trackpoint
 */

// Configure the SCL and SDA pins of the PS/2 mouse/tp using the `&pro_micro`
// notation.
//
// If possible, try to choose the blue high frequency pins to avoid
// bluetooth interference.
//
// On the nice!nano documentation these are green DX pins:
// https://nicekeyboards.com/docs/nice-nano/pinout-schematic
//
#define MOUSE_PS2_PIN_SCL_PRO_MICRO <&pro_micro 1 GPIO_ACTIVE_HIGH>
#define MOUSE_PS2_PIN_SDA_PRO_MICRO <&pro_micro 0 GPIO_ACTIVE_HIGH>


// Uncomment and configure this pin if you have an extra free pin and want the
// controller to perform the Power-On-Reset sequence, which many trackpoints
// require, instead of using a trackpoint reset circuit.
//
// It's ok to use a low-frequency pin for this.
#define MOUSE_PS2_PIN_RST_PRO_MICRO <&pro_micro 9 GPIO_ACTIVE_HIGH>


// Now configure the same SDA pin using the pinctrl notation.
//
// For that you have to use the PX.XX notation of the nrf52 chip.
//
// On the nice!nano pinout they are shown in blue and purple next to the green
// DX pin.
//
// Enter it like `X, Y` without leading zeroes.
// Examples:
// 		D0 - P0.08: 0, 8
//		D15 - P1.13: 1, 13
//
// We don't define the SCL pin, because UART uses a baud rate instead of
// a clock pin.
#define MOUSE_PS2_PIN_SDA_PINCTRL <NRF_PSEL(UART_RX, 0, 8)>


// In UART two different pins are used for receiving and transmitting, but PS/2
// uses the same pin for both.
//
// The UART config still requires both pins to be configured. So we use one of
// the nrf52 pins that are not exposed on the nice!nano board.
#define MOUSE_PS2_PIN_UNEXPOSED_TX <NRF_PSEL(UART_TX, 0, 27)>
#define MOUSE_PS2_PIN_UNEXPOSED_RX <NRF_PSEL(UART_RX, 0, 28)>


// The PS/2 GPIO driver
/ {
    gpio_ps2: gpio_ps2 {
		status = "disabled";
        compatible = "gpio-ps2";
        scl-gpios = MOUSE_PS2_PIN_SCL_PRO_MICRO;
        sda-gpios = MOUSE_PS2_PIN_SDA_PRO_MICRO;
    };
};


&pinctrl {
	// This pinctrl state is used for receiving
	// For `UART_TX`, set an unused and unexposed pin
	// For `UART_RX`, set the PS/2 SDA pin number
	uart0_ps2_default: uart0_ps2_default {
		group1 {
			psels = MOUSE_PS2_PIN_UNEXPOSED_TX,
					MOUSE_PS2_PIN_SDA_PINCTRL;
		};
	};

	// Set this to the same pins as uart0_ps2_default
	uart0_ps2_sleep: uart0_ps2_sleep {
		group1 {
			psels = MOUSE_PS2_PIN_UNEXPOSED_TX,
					MOUSE_PS2_PIN_SDA_PINCTRL;
			low-power-enable;
		};
	};

	// The nrf52 UART controller is not compatible with the PS/2
	// transmission frame. So we don't use UART for transmissions
	// and instead use GPIO bitbanging.
	//
	// When we switch to transmit mode, we free up the SDA pin by switching
	// UART to unexposed/unused pins.
	//
	// Then we can configure the pins to be used with the GPIO controller.
	uart0_ps2_off: uart0_ps2_off {
		group1 {
			psels = MOUSE_PS2_PIN_UNEXPOSED_TX,
					MOUSE_PS2_PIN_UNEXPOSED_RX;
		};
	};
};


&uart0 {
	status = "disabled";
	compatible = "nordic,nrf-uarte";

	// PS/2 uses a clock pin to syncronize data transmissions. UART on the
	// other hand uses a pre-defined frequency (baud rate).
	//
	// Fortunately, one of the available baud rates is very close to the
	// frequency used in IBM/Lenovo trackpoints.
	//
	// You can find other configurable baud rates here:
	// https://docs.zephyrproject.org/latest/build/dts/api/bindings/serial/nordic,nrf-uarte.html
	//
	// But most likely you won't need to adjust this.
	//
	// You can measure the frequency of your mouse/TP using a $5 logic
	// analyzer from AliExpress.
	//
	// Actual frequency of PS/2 trackpoint: 67us
	// Correspondent baud rate: 14,925
	//
	// Closest available baud rate in zephyr: 14,400
	// Correspondent cycle length: 69.44 microseconds
	//
	// Calculations:
	//
	// Convert cycle length in microseconds into baud:
	// 1 / PS2_CYCLE_LENGTH * 1000000 =  BAUD
	// 1 / 67 * 1000000 = 14,925 BAUD
	//
	// Convert baud into cycle length:
	// 1 / BAUD * 1000000 = CYCLE_LEN (in microseconds)
	// 1 / 14400 * 1000000 = 69.44
	//
	current-speed = <14400>;
	pinctrl-0 = <&uart0_ps2_default>;
	pinctrl-1 = <&uart0_ps2_off>;

	pinctrl-names = "default", "sleep";

    uart_ps2: uart_ps2 {
        status="disabled";
        compatible = "uart-ps2";
        scl-gpios = MOUSE_PS2_PIN_SCL_PRO_MICRO;
        sda-gpios = MOUSE_PS2_PIN_SDA_PRO_MICRO;
    };
};


/ {
    mouse_ps2: mouse_ps2 {
		status = "disabled";
        compatible = "zmk,input-mouse-ps2";

		// This will be overriden in your `xxx_right.overlay file`.
        // ps2-device = <&gpio_ps2>;
        ps2-device = <&uart_ps2>;

#ifdef MOUSE_PS2_PIN_RST_PRO_MICRO
        rst-gpios = MOUSE_PS2_PIN_RST_PRO_MICRO;
#endif
    };

    input_config: input_config {
      compatible = "zmk,input-configs";
      status = "disabled";

      mouse_ps2_config: mouse_ps2_config {
        device = <&mouse_ps2>;

		// Some of the available settings depend on the keymap. So they
		// are adjusted in...
		// ../../../includes/trackpoint.dtsi
      };
    };
};