| /* |
| * 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/hw.h" |
| #include "hw/sysbus.h" |
| #include "sysemu/sysemu.h" |
| #include "trace.h" |
| #include "qemu/error-report.h" |
| #include "sysemu/blockdev.h" |
| #include "hw/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, hwaddr 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, hwaddr 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 void milkymist_memcard_class_init(ObjectClass *klass, void *data) |
| { |
| DeviceClass *dc = DEVICE_CLASS(klass); |
| SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass); |
| |
| k->init = milkymist_memcard_init; |
| dc->reset = milkymist_memcard_reset; |
| dc->vmsd = &vmstate_milkymist_memcard; |
| } |
| |
| static const TypeInfo milkymist_memcard_info = { |
| .name = "milkymist-memcard", |
| .parent = TYPE_SYS_BUS_DEVICE, |
| .instance_size = sizeof(MilkymistMemcardState), |
| .class_init = milkymist_memcard_class_init, |
| }; |
| |
| static void milkymist_memcard_register_types(void) |
| { |
| type_register_static(&milkymist_memcard_info); |
| } |
| |
| type_init(milkymist_memcard_register_types) |