stm-game/dogs.c

/**
 * dogs.c - Interface for drawing to the EADOGS102N-6 display.
 * Copyright (C) 2020  Clyne Sullivan
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * See the GNU General Public License for more details.
 */

#include "ch.h"
#include "dogs.h"
#include "hal.h"

#define SET_DATA palSetPad(GPIOC, 15)
#define SET_CMD  palClearPad(GPIOC, 15)
#define CS_HIGH  palSetPad(GPIOA, 4)
#define CS_LOW   palClearPad(GPIOA, 4)
unsigned char dogs_buffer[DISP_WIDTH * DISP_HEIGHT / 8];

static volatile bool dogs_spi_done = false;

static void dogs_init_display();
static void dogs_spi_callback(SPIDriver *spid)
{
    if (spiIsBufferComplete(spid))
        dogs_spi_done = true;
}

void dogs_init()
{
    // SPI
    palSetPadMode(GPIOB, 1, PAL_MODE_ALTERNATE(1));     // MOSI
    palSetPadMode(GPIOA, 5, PAL_MODE_ALTERNATE(0));     // CLK
    palSetPadMode(GPIOA, 4, PAL_MODE_OUTPUT_PUSHPULL);  // nCS
    palSetPadMode(GPIOC, 14, PAL_MODE_OUTPUT_PUSHPULL); // nRST
    palSetPadMode(GPIOC, 15, PAL_MODE_OUTPUT_PUSHPULL); // CD

    palSetPad(GPIOA, 4);
    palSetPad(GPIOC, 14);
    palClearPad(GPIOC, 15);

    static const SPIConfig spicfg = {
        false,
        dogs_spi_callback,
        0, // cr1
        0
    };
    spiStart(&SPID1, &spicfg);

    dogs_init_display();
    dogs_clear();
    dogs_flush();
}

void dogs_write_data(unsigned char byte)
{
    SET_DATA;
    dogs_spi_done = false;
    spiStartSend(&SPID1, 1, &byte);
    while (!dogs_spi_done);
}
void dogs_write_cmd(unsigned char byte)
{
    SET_CMD;
    dogs_spi_done = false;
    spiStartSend(&SPID1, 1, &byte);
    while (!dogs_spi_done);
}

void dogs_set_column(unsigned int col)
{
    //if (col < DISP_WIDTH) {
        dogs_write_cmd(0x10 | ((col >> 4) & 0xF));
        dogs_write_cmd(0x00 | (col & 0xF));
    //}
}
void dogs_set_power(unsigned int bits)
{
    dogs_write_cmd(0x28 | (bits & 0x7));
}
void dogs_set_scroll_line(unsigned int startline)
{
    dogs_write_cmd(0x40 | (startline & 0x3F));
}
void dogs_set_page(unsigned int page)
{
    dogs_write_cmd(0xB0 | (page & 0xF));
}
void dogs_set_vlcd_ratio(unsigned int ratio)
{
    dogs_write_cmd(0x20 | (ratio & 0x7));
}
void dogs_set_contrast(unsigned int value)
{
    dogs_write_cmd(0x81);
    dogs_write_cmd(0x00 | (value & 0x3F));
}
void dogs_set_pixelson(bool on)
{
    dogs_write_cmd(on ? 0xA5 : 0xA4);
}
void dogs_set_invert(bool invert)
{
    dogs_write_cmd(invert ? 0xA7 : 0xA6);
}
void dogs_set_sleep(bool sleep)
{
    dogs_write_cmd(sleep ? 0xAE : 0xAF);
}
void dogs_set_segdir(bool normal)
{
    dogs_write_cmd(normal ? 0xA0 : 0xA1);
}
void dogs_set_comdir(bool normal)
{
    dogs_write_cmd(normal ? 0xC0 : 0xC8);
}
void dogs_reset()
{
    dogs_write_cmd(0xE2);
}
void dogs_set_bias(bool higher)
{
    dogs_write_cmd(higher ? 0xA2 : 0xA3);
}
void dogs_set_advanced(unsigned int bits)
{
    dogs_write_cmd(0xFA);
    dogs_write_cmd(0x10 | bits);
}

void dogs_init_display()
{
    CS_LOW;
    dogs_reset();
    CS_HIGH;
    chThdSleepMilliseconds(100);
    CS_LOW;
    dogs_set_scroll_line(0);
    dogs_set_segdir(true);
    dogs_set_comdir(false);
    dogs_set_pixelson(false);
    dogs_set_invert(false);
    dogs_set_bias(true);
    dogs_set_power(0x07);
    dogs_set_vlcd_ratio(7);
    dogs_set_contrast(0x10);
    dogs_set_advanced(0x83);
    dogs_set_sleep(false);
    CS_HIGH;
}

void dogs_clear()
{
    unsigned char *ptr = dogs_buffer;
    unsigned int count = sizeof(dogs_buffer);
    for (; count > 8; count -= 8) {
        *ptr++ = 0;
        *ptr++ = 0;
        *ptr++ = 0;
        *ptr++ = 0;
        *ptr++ = 0;
        *ptr++ = 0;
        *ptr++ = 0;
        *ptr++ = 0;
    }
}

void dogs_flush()
{
    unsigned char *ptr = dogs_buffer;
    CS_LOW;
    for (int page = 0; page < 8; page++) {
        dogs_set_page(page);
        dogs_set_column(30);

        SET_DATA;
        dogs_spi_done = false;
        spiStartSend(&SPID1, 102, ptr);
        ptr += 102;
        while (!dogs_spi_done);
    }
    CS_HIGH;
}

void draw_pixel(int x, int y, bool state)
{
    if (state)
        dogs_buffer[y / 8 * DISP_WIDTH + x] |= (1 << (y % 8));
    else
        dogs_buffer[y / 8 * DISP_WIDTH + x] &= ~(1 << (y % 8));
}

void draw_bitmap(int x, int y, const unsigned char *buffer)
{
    // Prepare source information
    const unsigned char *src = buffer;
    const int width = *src++;
    const int height = *src++;
    int sbit = 0;

    for (int j = 0; j < height; j++) {
        for (int i = 0; i < width; i++) {
            draw_pixel(x + i, y + j, *src & (1 << sbit));
            if (++sbit == 8) {
                sbit = 0;
                ++src;
            }
        }
    }
}