f256/f256lib/f_dma.c

96 lines
2.5 KiB
C

/*
* Copyright (c) 2024 Scott Duensing, scott@kangaroopunch.com
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef WITHOUT_DMA
#ifndef F256LIB_AMALGAMATED_BUILD
#include "f_dma.h"
#endif
//static void dmaWait(void);
void dmaFill(uint32_t start, uint32_t length, byte value) {
while (PEEKW(RAST_ROW_L) != 482); // Wait for VBL.
POKE(DMA_CTRL, DMA_CTRL_FILL | DMA_CTRL_ENABLE);
POKE(DMA_FILL_VAL, value);
POKEA(DMA_DST_ADDR, start);
POKEA(DMA_COUNT, length);
POKE(DMA_CTRL, PEEK(DMA_CTRL) | DMA_CTRL_START);
// dmaWait();
}
void dma2dFill(uint32_t start, uint16_t width, uint16_t height, uint16_t stride, byte value) {
while (PEEKW(RAST_ROW_L) != 482); // Wait for VBL.
asm("sei");
POKE(DMA_CTRL, DMA_CTRL_2D | DMA_CTRL_FILL | DMA_CTRL_ENABLE);
POKE(DMA_FILL_VAL, value);
POKEA(DMA_DST_ADDR, start);
POKEW(DMA_WIDTH, width);
POKEW(DMA_HEIGHT, height);
POKEW(DMA_STRIDE_DST, stride);
POKE(DMA_CTRL, PEEK(DMA_CTRL) | DMA_CTRL_START);
asm("nop");
asm("nop");
asm("nop");
asm("nop");
asm("nop");
asm("nop");
asm("cli");
// dmaWait();
}
void dmaReset(void) {
// Disable DMA.
POKE(DMA_CTRL, 0);
}
/*
static void dmaWait(void) {
// ***FIX*** This whole block seems unneeded if DMA halts the CPU while it transfers.
// First, wait for DMA to be complete.
while (PEEK(DMA_STATUS) & DMA_STAT_BUSY)
// Spin our wheels.
;
POKE(DMA_CTRL, 0);
// Then wait for a VBL because two DMAs per frame will crash.
//graphicsWaitVerticalBlank();
}
*/
#endif