dreamcast2: add maple_get_condition

This commit is contained in:
Zack Buhman 2025-09-03 15:56:20 -05:00
parent fa5d7315d6
commit b2c7b9e53c
2 changed files with 347 additions and 0 deletions

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@ -99,3 +99,9 @@ MAPLE_DEVICE_REQUEST_OBJ = \
example/maple_device_request.elf: LDSCRIPT = $(LIB)/main.lds example/maple_device_request.elf: LDSCRIPT = $(LIB)/main.lds
example/maple_device_request.elf: $(START_OBJ) $(MAPLE_DEVICE_REQUEST_OBJ) example/maple_device_request.elf: $(START_OBJ) $(MAPLE_DEVICE_REQUEST_OBJ)
MAPLE_GET_CONDITION_OBJ = \
example/maple_get_condition.o
example/maple_get_condition.elf: LDSCRIPT = $(LIB)/main.lds
example/maple_get_condition.elf: $(START_OBJ) $(MAPLE_GET_CONDITION_OBJ)

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@ -0,0 +1,341 @@
#include "systembus/systembus.hpp"
#include "systembus/systembus_bits.hpp"
#include "maple/maple_bits.hpp"
#include "maple/maple_host.hpp"
#include "maple/maple_bus_commands.hpp"
#include "maple/maple_bus_bits.hpp"
#include "maple/maple_bus_ft0.hpp"
#include "maple/maple_bus_ft6.hpp"
#include "sh7091/sh7091.hpp"
#include "sh7091/sh7091_bits.hpp"
static inline void character(const char c)
{
using sh7091::sh7091;
using namespace sh7091;
// set the transmit trigger to `1 byte`--this changes the behavior of TDFE
sh7091.SCIF.SCFCR2 = scif::scfcr2::ttrg::trigger_on_1_bytes;
// wait for transmit fifo to become partially empty
while ((sh7091.SCIF.SCFSR2 & scif::scfsr2::tdfe::bit_mask) == 0);
// unset tdfe bit
sh7091.SCIF.SCFSR2 = (uint16_t)(~scif::scfsr2::tdfe::bit_mask);
sh7091.SCIF.SCFTDR2 = c;
}
static void string(const char * s)
{
while (*s != 0) {
character(*s++);
}
}
static void print_base16(uint32_t n, int len)
{
char buf[len];
char * bufi = &buf[len - 1];
while (bufi >= buf) {
uint32_t nib = n & 0xf;
n = n >> 4;
if (nib > 9) {
nib += (97 - 10);
} else {
nib += (48 - 0);
}
*bufi = nib;
bufi -= 1;
}
for (int i = 0; i < len; i++) {
character(buf[i]);
}
}
constexpr inline uint32_t align_32byte(uint32_t mem)
{
return (mem + 31) & ~31;
}
/*
See DCDBSysArc990907E.pdf page 274.
Maple DMA uses SH4 DMA channel 0 in "DDT" mode. This means that Holly's Maple
DMA functional unit is externally controlling the SH4's DMA unit.
The Dreamcast boot rom leaves channel 0 already configured for Maple DMA,
though if you felt rebellious and wished to used channel 0 for something else,
you would need to reconfigure channel 0 for Maple/DDT afterwards.
Note that this `maple_dma_start` function does not configure SH4 DMA channel
0, and presumes it is already in the correct state.
*/
void maple_dma_start(void * command_buf, uint32_t send_size,
void * response_buf, uint32_t recv_size)
{
// write back operand cache blocks for command buffer prior to starting DMA
for (uint32_t i = 0; i < align_32byte(send_size) / 32; i++) {
asm volatile ("ocbwb @%0"
:
: "r" (reinterpret_cast<uint32_t>(((uint32_t)command_buf) + 32 * i))
);
}
using systembus::maple_if;
using systembus::systembus;
using namespace maple;
using namespace systembus;
// if SH4 cache were enabled, it would be necessary to use the `ocbwb` sh4
// instruction to write back the cache to system memory, prior to continuing.
// if SH4 cache were enabled, it would be necessary to use the `ocbi` sh4
// instruction to invalidate any possibly-cached areas of the receive buffer,
// as these are imminently going to be rewritten by the DMA unit independently
// of cache access.
// disable Maple DMA and abort any possibly-in-progress transfers
maple_if.MDEN = mden::dma_enable::abort;
while ((maple_if.MDST & mdst::start_status::bit_mask) != 0);
// clear Maple DMA end status
systembus.ISTNRM = istnrm::end_of_dma_maple_dma;
// 20nsec maple_if. 0xc350 = 1ms
uint32_t one_msec = 0xc350;
// set the Maple bus controller timeout and transfer rate
maple_if.MSYS = msys::time_out_counter(one_msec)
| msys::sending_rate::_2M;
// MDAPRO controls which (system memory) addresses are considered valid for
// Maple DMA. An attempt to use an address outside of this range will cause an
// error interrupt in from the Maple DMA unit.
//
// 0x40 through 0x7F allows for transfers from 0x0c000000 to 0x0fffffff
// System Memory is 0x0c000000 through 0x0cffffff (16MB)
//
// It is probably possible to do strange things such as use texture memory as
// a Maple DMA receive buffer, but TOP_ADDRESS would need to be lowered
// accordingly.
maple_if.MDAPRO = mdapro::security_code
| mdapro::top_address(0x40)
| mdapro::bottom_address(0x7f);
// SOFTWARE_INITIATION allows a Maple DMA transfer to be initiated by a write
// to the MDST register.
maple_if.MDTSEL = mdtsel::trigger_select::software_initiation;
// the Maple DMA start address must be 32-byte aligned
maple_if.MDSTAR = mdstar::table_address((uint32_t)command_buf);
// re-enable Maple DMA
maple_if.MDEN = mden::dma_enable::enable;
// start Maple DMA (completes asynchronously)
maple_if.MDST = mdst::start_status::start;
// write back operand cache blocks for command buffer prior to starting DMA
for (uint32_t i = 0; i < align_32byte(recv_size) / 32; i++) {
asm volatile ("ocbi @%0"
:
: "r" (reinterpret_cast<uint32_t>(((uint32_t)response_buf) + 32 * i))
);
}
}
int maple_dma_wait_complete()
{
using systembus::systembus;
using namespace systembus;
// wait for Maple DMA completion
while ((systembus.ISTNRM & istnrm::end_of_dma_maple_dma) == 0) {
if (systembus.ISTERR) {
string("ISTERR ");
print_base16(systembus.ISTERR, 8);
character('\n');
if ((systembus.ISTERR >> 11) & 1) {
return -1;
}
}
}
// clear Maple DMA end status
systembus.ISTNRM = istnrm::end_of_dma_maple_dma;
return 0;
}
template <typename C, typename R>
void maple_device_request(maple::host_command<typename C::data_fields> * host_command,
maple::host_response<typename R::data_fields> * host_response,
bool end_flag = false)
{
using namespace maple;
constexpr uint32_t data_size = (sizeof (typename C::data_fields));
host_command->host_instruction = (end_flag ? host_instruction::end_flag : 0)
| host_instruction::port_select::a
| host_instruction::pattern::normal
| host_instruction::transfer_length(data_size / 4);
host_command->receive_data_address = ((uint32_t)host_response) & receive_data_address::mask;
host_command->header.command_code = C::command_code;
host_command->header.destination_ap = ap::port_select::a
| ap::de::device;
host_command->header.source_ap = ap::port_select::a
| ap::de::port;
host_command->header.data_size = data_size / 4;
}
// the Maple bus protocol is big endian, but the SH4 is running in little endian mode
#define bswap32 __builtin_bswap32
#define bswap16 __builtin_bswap16
void main()
{
// Maple DMA buffers must be 32-byte aligned
uint8_t send_buf[1024] __attribute__((aligned(32)));
uint8_t recv_buf[1024] __attribute__((aligned(32)));
struct requests {
maple::host_command<maple::device_request::data_fields> device_request;
maple::host_command<maple::get_condition::data_fields> get_condition;
};
static_assert((sizeof (requests)) == (sizeof (maple::host_command<maple::device_request::data_fields>)) + (sizeof (maple::host_command<maple::get_condition::data_fields>)));
using maple__data_transfer = maple::data_transfer<maple::ft0::data_transfer::data_format>;
struct responses {
maple::host_response<maple::device_status::data_fields> device_status;
maple::host_response<maple__data_transfer::data_fields> data_transfer;
};
auto requests = (struct requests *)send_buf;
auto responses = (struct responses *)recv_buf;
// fill send_buf with a "device request" command
// recv_buf is reply destination address
maple_device_request<maple::device_request, maple::device_status>(&requests->device_request, &responses->device_status);
maple_device_request<maple::get_condition, maple__data_transfer>(&requests->get_condition, &responses->data_transfer, true);
requests->get_condition.data.function_type = bswap32(maple::function_type::controller);
systembus::systembus.ISTERR = 0xffffffff;
maple_dma_start(send_buf, (sizeof (struct requests)),
recv_buf, (sizeof (struct responses)));
string("wait\n");
int res = maple_dma_wait_complete();
if (res != 0) {
string(" ");
return;
}
if (responses->device_status.header.command_code != maple::device_status::command_code) {
string("maple port A: invalid response or disconnected\n");
string(" ");
return;
}
//////////////////////////////////////////////////////////////////////////////
// data transfer
//////////////////////////////////////////////////////////////////////////////
string("responses->device_status:\n");
string(" header:\n");
string(" command_code : ");
print_base16(responses->device_status.header.command_code, 2); character('\n');
string(" destination_ap : ");
print_base16(responses->device_status.header.destination_ap, 2); character('\n');
string(" source_ap : ");
print_base16(responses->device_status.header.source_ap, 2); character('\n');
string(" data_size : ");
print_base16(responses->device_status.header.data_size, 2); character('\n');
auto& device_status = responses->device_status.data;
string(" data:\n");
string(" device_id:\n");
string(" ft : ");
print_base16(bswap32(device_status.device_id.ft), 8); character('\n');
string(" fd[0]: ");
print_base16(bswap32(device_status.device_id.fd[0]), 8); character('\n');
string(" fd[1]: ");
print_base16(bswap32(device_status.device_id.fd[1]), 8); character('\n');
string(" fd[2]: ");
print_base16(bswap32(device_status.device_id.fd[2]), 8); character('\n');
string(" destination_code: ");
print_base16(bswap32(device_status.destination_code), 2); character('\n');
string(" connection_direction: ");
print_base16(bswap32(device_status.connection_direction), 2); character('\n');
string(" product_name: \"");
for (int i = 0; i < 30; i++)
character(device_status.product_name[i]);
string("\"\n");
string(" license: \"");
for (int i = 0; i < 60; i++)
character(device_status.license[i]);
string("\"\n");
string(" low_consumption_standby_current: ");
print_base16(bswap16(device_status.low_consumption_standby_current), 4); character('\n');
string(" maximum_current_consumption: ");
print_base16(bswap16(device_status.maximum_current_consumption), 4); character('\n');
//////////////////////////////////////////////////////////////////////////////
// data transfer
//////////////////////////////////////////////////////////////////////////////
if (responses->data_transfer.header.command_code != maple__data_transfer::command_code) {
string("maple port A: invalid response or disconnected\n");
print_base16(responses->data_transfer.header.command_code, 8);
character('\n');
string(" ");
return;
}
string("responses->data_transfer:\n");
string(" header:\n");
string(" command_code : ");
print_base16(responses->data_transfer.header.command_code, 2); character('\n');
string(" destination_ap : ");
print_base16(responses->data_transfer.header.destination_ap, 2); character('\n');
string(" source_ap : ");
print_base16(responses->data_transfer.header.source_ap, 2); character('\n');
string(" data_size : ");
print_base16(responses->data_transfer.header.data_size, 2); character('\n');
auto& data_transfer = responses->data_transfer.data;
string(" data:\n");
string(" function_type: ");
print_base16(bswap32(data_transfer.function_type), 8); character('\n');
string(" data:\n");
string(" digital_button: ");
print_base16(bswap16(data_transfer.data.digital_button), 4); character('\n');
string(" analog_coordinate_axis[0]: ");
print_base16(data_transfer.data.analog_coordinate_axis[0], 2); character('\n');
string(" analog_coordinate_axis[1]: ");
print_base16(data_transfer.data.analog_coordinate_axis[1], 2); character('\n');
string(" analog_coordinate_axis[2]: ");
print_base16(data_transfer.data.analog_coordinate_axis[2], 2); character('\n');
string(" analog_coordinate_axis[3]: ");
print_base16(data_transfer.data.analog_coordinate_axis[3], 2); character('\n');
string(" analog_coordinate_axis[4]: ");
print_base16(data_transfer.data.analog_coordinate_axis[4], 2); character('\n');
string(" analog_coordinate_axis[5]: ");
print_base16(data_transfer.data.analog_coordinate_axis[5], 2); character('\n');
string(" ");
}