/* * QEMU model of the Milkymist SD Card Controller. * * Copyright (c) 2010 Michael Walle <michael@walle.cc> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see <http://www.gnu.org/licenses/>. * * * Specification available at: * http://www.milkymist.org/socdoc/memcard.pdf */ #include "hw.h" #include "sysbus.h" #include "sysemu.h" #include "trace.h" #include "qemu-error.h" #include "blockdev.h" #include "sd.h" enum { ENABLE_CMD_TX = (1<<0), ENABLE_CMD_RX = (1<<1), ENABLE_DAT_TX = (1<<2), ENABLE_DAT_RX = (1<<3), }; enum { PENDING_CMD_TX = (1<<0), PENDING_CMD_RX = (1<<1), PENDING_DAT_TX = (1<<2), PENDING_DAT_RX = (1<<3), }; enum { START_CMD_TX = (1<<0), START_DAT_RX = (1<<1), }; enum { R_CLK2XDIV = 0, R_ENABLE, R_PENDING, R_START, R_CMD, R_DAT, R_MAX }; struct MilkymistMemcardState { SysBusDevice busdev; MemoryRegion regs_region; SDState *card; int command_write_ptr; int response_read_ptr; int response_len; int ignore_next_cmd; int enabled; uint8_t command[6]; uint8_t response[17]; uint32_t regs[R_MAX]; }; typedef struct MilkymistMemcardState MilkymistMemcardState; static void update_pending_bits(MilkymistMemcardState *s) { /* transmits are instantaneous, thus tx pending bits are never set */ s->regs[R_PENDING] = 0; /* if rx is enabled the corresponding pending bits are always set */ if (s->regs[R_ENABLE] & ENABLE_CMD_RX) { s->regs[R_PENDING] |= PENDING_CMD_RX; } if (s->regs[R_ENABLE] & ENABLE_DAT_RX) { s->regs[R_PENDING] |= PENDING_DAT_RX; } } static void memcard_sd_command(MilkymistMemcardState *s) { SDRequest req; req.cmd = s->command[0] & 0x3f; req.arg = (s->command[1] << 24) | (s->command[2] << 16) | (s->command[3] << 8) | s->command[4]; req.crc = s->command[5]; s->response[0] = req.cmd; s->response_len = sd_do_command(s->card, &req, s->response+1); s->response_read_ptr = 0; if (s->response_len == 16) { /* R2 response */ s->response[0] = 0x3f; s->response_len += 1; } else if (s->response_len == 4) { /* no crc calculation, insert dummy byte */ s->response[5] = 0; s->response_len += 2; } if (req.cmd == 0) { /* next write is a dummy byte to clock the initialization of the sd * card */ s->ignore_next_cmd = 1; } } static uint64_t memcard_read(void *opaque, target_phys_addr_t addr, unsigned size) { MilkymistMemcardState *s = opaque; uint32_t r = 0; addr >>= 2; switch (addr) { case R_CMD: if (!s->enabled) { r = 0xff; } else { r = s->response[s->response_read_ptr++]; if (s->response_read_ptr > s->response_len) { error_report("milkymist_memcard: " "read more cmd bytes than available. Clipping."); s->response_read_ptr = 0; } } break; case R_DAT: if (!s->enabled) { r = 0xffffffff; } else { r = 0; r |= sd_read_data(s->card) << 24; r |= sd_read_data(s->card) << 16; r |= sd_read_data(s->card) << 8; r |= sd_read_data(s->card); } break; case R_CLK2XDIV: case R_ENABLE: case R_PENDING: case R_START: r = s->regs[addr]; break; default: error_report("milkymist_memcard: read access to unknown register 0x" TARGET_FMT_plx, addr << 2); break; } trace_milkymist_memcard_memory_read(addr << 2, r); return r; } static void memcard_write(void *opaque, target_phys_addr_t addr, uint64_t value, unsigned size) { MilkymistMemcardState *s = opaque; trace_milkymist_memcard_memory_write(addr, value); addr >>= 2; switch (addr) { case R_PENDING: /* clear rx pending bits */ s->regs[R_PENDING] &= ~(value & (PENDING_CMD_RX | PENDING_DAT_RX)); update_pending_bits(s); break; case R_CMD: if (!s->enabled) { break; } if (s->ignore_next_cmd) { s->ignore_next_cmd = 0; break; } s->command[s->command_write_ptr] = value & 0xff; s->command_write_ptr = (s->command_write_ptr + 1) % 6; if (s->command_write_ptr == 0) { memcard_sd_command(s); } break; case R_DAT: if (!s->enabled) { break; } sd_write_data(s->card, (value >> 24) & 0xff); sd_write_data(s->card, (value >> 16) & 0xff); sd_write_data(s->card, (value >> 8) & 0xff); sd_write_data(s->card, value & 0xff); break; case R_ENABLE: s->regs[addr] = value; update_pending_bits(s); break; case R_CLK2XDIV: case R_START: s->regs[addr] = value; break; default: error_report("milkymist_memcard: write access to unknown register 0x" TARGET_FMT_plx, addr << 2); break; } } static const MemoryRegionOps memcard_mmio_ops = { .read = memcard_read, .write = memcard_write, .valid = { .min_access_size = 4, .max_access_size = 4, }, .endianness = DEVICE_NATIVE_ENDIAN, }; static void milkymist_memcard_reset(DeviceState *d) { MilkymistMemcardState *s = container_of(d, MilkymistMemcardState, busdev.qdev); int i; s->command_write_ptr = 0; s->response_read_ptr = 0; s->response_len = 0; for (i = 0; i < R_MAX; i++) { s->regs[i] = 0; } } static int milkymist_memcard_init(SysBusDevice *dev) { MilkymistMemcardState *s = FROM_SYSBUS(typeof(*s), dev); DriveInfo *dinfo; dinfo = drive_get_next(IF_SD); s->card = sd_init(dinfo ? dinfo->bdrv : NULL, 0); s->enabled = dinfo ? bdrv_is_inserted(dinfo->bdrv) : 0; memory_region_init_io(&s->regs_region, &memcard_mmio_ops, s, "milkymist-memcard", R_MAX * 4); sysbus_init_mmio(dev, &s->regs_region); return 0; } static const VMStateDescription vmstate_milkymist_memcard = { .name = "milkymist-memcard", .version_id = 1, .minimum_version_id = 1, .minimum_version_id_old = 1, .fields = (VMStateField[]) { VMSTATE_INT32(command_write_ptr, MilkymistMemcardState), VMSTATE_INT32(response_read_ptr, MilkymistMemcardState), VMSTATE_INT32(response_len, MilkymistMemcardState), VMSTATE_INT32(ignore_next_cmd, MilkymistMemcardState), VMSTATE_INT32(enabled, MilkymistMemcardState), VMSTATE_UINT8_ARRAY(command, MilkymistMemcardState, 6), VMSTATE_UINT8_ARRAY(response, MilkymistMemcardState, 17), VMSTATE_UINT32_ARRAY(regs, MilkymistMemcardState, R_MAX), VMSTATE_END_OF_LIST() } }; static SysBusDeviceInfo milkymist_memcard_info = { .init = milkymist_memcard_init, .qdev.name = "milkymist-memcard", .qdev.size = sizeof(MilkymistMemcardState), .qdev.vmsd = &vmstate_milkymist_memcard, .qdev.reset = milkymist_memcard_reset, }; static void milkymist_memcard_register(void) { sysbus_register_withprop(&milkymist_memcard_info); } device_init(milkymist_memcard_register)