Mercurial > repos > blastem
diff megawifi.c @ 1513:8f3b6a64b658
Initial work on MegaWiFi support
author | Michael Pavone <pavone@retrodev.com> |
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date | Mon, 15 Jan 2018 09:04:43 -0800 |
parents | |
children | 4f94e0f90c83 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/megawifi.c Mon Jan 15 09:04:43 2018 -0800 @@ -0,0 +1,238 @@ +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include "genesis.h" + +enum { + TX_IDLE, + TX_LEN1, + TX_LEN2, + TX_PAYLOAD, + TX_WAIT_ETX +}; +#define STX 0x7E +#define ETX 0x7E + +#define E(N) N +enum { +#include "mw_commands.c" + CMD_ERROR = 255 +}; +#undef E +#define E(N) #N +static const char *cmd_names[] = { +#include "mw_commands.c" + [255] = "CMD_ERROR" +}; + +enum { + STATE_IDLE=1, + STATE_AP_JOIN, + STATE_SCAN, + STATE_READY, + STATE_TRANSPARENT +}; + +#define FLAG_ONLINE + +typedef struct { + uint32_t transmit_bytes; + uint32_t expected_bytes; + uint32_t receive_bytes; + uint32_t receive_read; + uint16_t channel_flags; + uint8_t scratchpad; + uint8_t transmit_channel; + uint8_t transmit_state; + uint8_t module_state; + uint8_t flags; + uint8_t transmit_buffer[4096]; + uint8_t receive_buffer[4096]; +} megawifi; + +static megawifi *get_megawifi(void *context) +{ + m68k_context *m68k = context; + genesis_context *gen = m68k->system; + if (!gen->extra) { + gen->extra = calloc(1, sizeof(megawifi)); + ((megawifi *)gen->extra)->module_state = STATE_IDLE; + } + return gen->extra; +} + +static void mw_putc(megawifi *mw, uint8_t v) +{ + if (mw->receive_bytes == sizeof(mw->receive_buffer)) { + return; + } + mw->receive_buffer[mw->receive_bytes++] = v; +} + +static void mw_puts(megawifi *mw, char *s) +{ + uint32_t len = strlen(s); + if ((mw->receive_bytes + len) > sizeof(mw->receive_buffer)) { + return; + } + memcpy(mw->receive_buffer + mw->receive_bytes, s, len); + mw->receive_bytes += len; +} + +static void process_packet(megawifi *mw) +{ + if (mw->transmit_channel == 0) { + uint32_t command = mw->transmit_buffer[0] << 8 | mw->transmit_buffer[1]; + uint32_t size = mw->transmit_buffer[2] << 8 | mw->transmit_buffer[3]; + if (size > mw->transmit_bytes - 4) { + size = mw->transmit_bytes - 4; + } + mw->receive_read = mw->receive_bytes = 0; + switch (command) + { + case CMD_VERSION: + //LSD header + mw_putc(mw, 0x7E); + mw_putc(mw, 0); + mw->receive_bytes += 1; //reserve space for LSB of len + //cmd + mw_putc(mw, 0); + mw_putc(mw, CMD_OK); + //length + mw_putc(mw, 0); + mw->receive_bytes += 1; //reserve space for LSB of len + mw_putc(mw, 1); + mw_putc(mw, 0); + mw_puts(mw, "blastem"); + mw->receive_buffer[2] = mw->receive_bytes - 3; + mw->receive_buffer[6] = mw->receive_bytes - 7; + mw_putc(mw, 0x7E); + break; + case CMD_ECHO: + mw->receive_bytes = mw->transmit_bytes; + memcpy(mw->receive_buffer, mw->transmit_buffer, mw->transmit_bytes); + break; + case CMD_AP_JOIN: + mw->module_state = STATE_READY; + mw_putc(mw, 0x7E); + mw_putc(mw, 0); + mw_putc(mw, 4); + //cmd + mw_putc(mw, 0); + mw_putc(mw, CMD_OK); + //length + mw_putc(mw, 0); + mw_putc(mw, 0); + mw_putc(mw, 0x7E); + break; + case CMD_SYS_STAT: + //LSD header + mw_putc(mw, 0x7E); + mw_putc(mw, 0); + mw_putc(mw, 8); + //cmd + mw_putc(mw, 0); + mw_putc(mw, CMD_OK); + //length + mw_putc(mw, 0); + mw_putc(mw, 4); + mw_putc(mw, mw->module_state); + mw_putc(mw, mw->flags); + mw_putc(mw, mw->channel_flags >> 8); + mw_putc(mw, mw->channel_flags); + mw_putc(mw, 0x7E); + break; + default: + printf("Unhandled MegaWiFi command %s(%d) with length %X\n", cmd_names[command], command, size); + break; + } + } else { + printf("Unhandled receive of MegaWiFi data on channel %d\n", mw->transmit_channel); + } + mw->transmit_bytes = mw->expected_bytes = 0; +} + +void *megawifi_write_b(uint32_t address, void *context, uint8_t value) +{ + if (!(address & 1)) { + return context; + } + megawifi *mw = get_megawifi(context); + address = address >> 1 & 7; + switch (address) + { + case 0: + switch (mw->transmit_state) + { + case TX_IDLE: + if (value == STX) { + mw->transmit_state = TX_LEN1; + } + break; + case TX_LEN1: + mw->transmit_channel = value >> 4; + mw->expected_bytes = value << 8 & 0xF00; + mw->transmit_state = TX_LEN2; + break; + case TX_LEN2: + mw->expected_bytes |= value; + mw->transmit_state = TX_PAYLOAD; + break; + case TX_PAYLOAD: + mw->transmit_buffer[mw->transmit_bytes++] = value; + if (mw->transmit_bytes == mw->expected_bytes) { + mw->transmit_state = TX_WAIT_ETX; + } + break; + case TX_WAIT_ETX: + if (value == ETX) { + mw->transmit_state = TX_IDLE; + process_packet(mw); + } + break; + } + break; + case 7: + mw->scratchpad = value; + break; + default: + printf("Unhandled write to MegaWiFi UART register %X: %X\n", address, value); + } + return context; +} + +void *megawifi_write_w(uint32_t address, void *context, uint16_t value) +{ + return megawifi_write_b(address | 1, context, value); +} + +uint8_t megawifi_read_b(uint32_t address, void *context) +{ + + if (!(address & 1)) { + return 0xFF; + } + megawifi *mw = get_megawifi(context); + address = address >> 1 & 7; + switch (address) + { + case 0: + if (mw->receive_read < mw->receive_bytes) { + return mw->receive_buffer[mw->receive_read++]; + } + return 0xFF; + case 5: + //line status + return 0x60 | (mw->receive_read < mw->receive_bytes); + case 7: + return mw->scratchpad; + default: + printf("Unhandled read from MegaWiFi UART register %X\n", address); + return 0xFF; + } +} + +uint16_t megawifi_read_w(uint32_t address, void *context) +{ + return 0xFF00 | megawifi_read_b(address | 1, context); +}