mirror of
https://github.com/dingusdev/dingusppc.git
synced 2024-11-18 22:05:51 +00:00
102 lines
2.6 KiB
C++
102 lines
2.6 KiB
C++
/*
|
|
DingusPPC - The Experimental PowerPC Macintosh emulator
|
|
Copyright (C) 2018-20 divingkatae and maximum
|
|
(theweirdo) spatium
|
|
|
|
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
|
|
|
|
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.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
/** @file Descriptor-based direct memory access emulation.
|
|
|
|
Official documentation can be found in the fifth chapter of the book
|
|
"Macintosh Technology in the Common Hardware Reference Platform"
|
|
by Apple Computer, Inc.
|
|
*/
|
|
|
|
#ifndef DB_DMA_H
|
|
#define DB_DMA_H
|
|
|
|
#include <cinttypes>
|
|
|
|
/** DBDMA Channel registers offsets */
|
|
enum DMAReg : uint32_t {
|
|
CH_CTRL = 0,
|
|
CH_STAT = 4,
|
|
CMD_PTR_LO = 12,
|
|
};
|
|
|
|
/** Channel Status bits (DBDMA spec, 5.5.3) */
|
|
enum {
|
|
CH_STAT_ACTIVE = 0x400,
|
|
CH_STAT_DEAD = 0x800,
|
|
CH_STAT_WAKE = 0x1000,
|
|
CH_STAT_FLUSH = 0x2000,
|
|
CH_STAT_PAUSE = 0x4000,
|
|
CH_STAT_RUN = 0x8000
|
|
};
|
|
|
|
/** DBDMA command (DBDMA spec, 5.6.1) - all fields are little-endian! */
|
|
typedef struct DMACmd {
|
|
uint16_t req_count;
|
|
uint8_t cmd_bits;
|
|
uint8_t cmd_key;
|
|
uint32_t address;
|
|
uint32_t cmd_arg;
|
|
uint16_t res_count;
|
|
uint16_t xfer_stat;
|
|
} DMACmd;
|
|
|
|
class DMACallback {
|
|
public:
|
|
virtual void dma_start(void) = 0;
|
|
virtual void dma_end(void) = 0;
|
|
//virtual void dma_push(uint8_t *buf, int size) = 0;
|
|
//virtual void dma_pull(uint8_t *buf, int size) = 0;
|
|
};
|
|
|
|
class DMAChannel {
|
|
public:
|
|
DMAChannel(DMACallback* cb) {
|
|
this->dma_cb = cb;
|
|
};
|
|
~DMAChannel() = default;
|
|
|
|
uint32_t reg_read(uint32_t offset, int size);
|
|
void reg_write(uint32_t offset, uint32_t value, int size);
|
|
|
|
int get_data(uint32_t req_len, uint32_t *avail_len, uint8_t **p_data);
|
|
bool is_active();
|
|
|
|
protected:
|
|
void get_next_cmd(uint32_t cmd_addr, DMACmd* p_cmd);
|
|
uint8_t interpret_cmd(void);
|
|
|
|
void start(void);
|
|
void resume(void);
|
|
void abort(void);
|
|
void pause(void);
|
|
|
|
private:
|
|
DMACallback* dma_cb = 0;
|
|
uint16_t ch_stat = 0;
|
|
uint32_t cmd_ptr = 0;
|
|
|
|
uint32_t queue_len;
|
|
uint8_t* queue_data;
|
|
};
|
|
|
|
#endif /* DB_DMA_H */
|