dingusppc/devices/common/dmacore.h
2024-07-15 02:09:15 +02:00

128 lines
3.4 KiB
C++

/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-24 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 Core definitions for direct memory access (DMA) emulation. */
#ifndef DMA_CORE_H
#define DMA_CORE_H
#include <cstdint>
#include <cinttypes>
#include <string>
enum DmaPullResult : int {
MoreData, // data source has more data to be pulled
NoMoreData, // data source has no more data to be pulled
};
class DmaOutChannel {
public:
DmaOutChannel(std::string name) { this->name = name; };
virtual bool is_out_active() { return true; };
virtual DmaPullResult pull_data(uint32_t req_len, uint32_t *avail_len,
uint8_t **p_data) = 0;
virtual int get_pull_data_remaining() { return 1; };
virtual void end_pull_data() { };
std::string get_name(void) { return this->name; };
private:
std::string name;
};
class DmaInChannel {
public:
DmaInChannel(std::string name) { this->name = name; };
virtual bool is_in_active() { return true; };
virtual int push_data(const char* src_ptr, int len) = 0;
virtual int get_push_data_remaining() { return 1; };
virtual void end_push_data() { };
std::string get_name(void) { return this->name; };
private:
std::string name;
};
// Base class for bidirectional DMA channels.
class DmaBidirChannel : public DmaOutChannel, public DmaInChannel {
public:
DmaBidirChannel(std::string name) : DmaOutChannel(name + " Out"),
DmaInChannel(name + std::string(" In")) { this->name = name; };
std::string get_name(void) { return this->name; };
private:
std::string name;
};
// ---------------------- New DMA API -------------------------
enum DmaMsg : unsigned {
CH_START = 1,
CH_STOP,
DATA_AVAIL,
};
enum XferDir : unsigned {
DMA_DIR_UNDEF = 0,
DMA_DIR_TO_DEV,
DMA_DIR_FROM_DEV,
};
class DmaChannel;
class DmaDevice {
public:
DmaDevice() = default;
~DmaDevice() = default;
void connect(DmaChannel *ch_obj) { this->channel_obj = ch_obj; };
void notify(DmaMsg msg) {};
virtual int xfer_from(uint8_t *buf, int len) { return len; };
protected:
DmaChannel* channel_obj = nullptr;
};
class DmaChannel {
public:
DmaChannel() = default;
~DmaChannel() = default;
void connect(DmaDevice *dev_obj) { this->dev_obj = dev_obj; };
void notify(DmaMsg msg) {};
protected:
DmaDevice* dev_obj = nullptr;
XferDir xfer_dir = DMA_DIR_UNDEF;
};
/*
TODO: write CONNECT macro that
- constructs both DmaChannel and DmaDevice objects
- calls connect() method on both objects
- initializes DMA interrupts
*/
#endif // DMA_CORE_H