[Qemu-devel] [RFC PATCH v1 2/4] m25p80: initial verion

[Peter A. G. Crosthwaite]

Added device model for m25p80 SPI flash

Signed-off-by: Peter A. G. Crosthwaite <address@hidden>
---
 Makefile.target |    1 +
 hw/m25p80.c     |  495 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 496 insertions(+), 0 deletions(-)
 create mode 100644 hw/m25p80.c

diff --git a/Makefile.target b/Makefile.target
index 8fd3718..fcccf1b 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -321,6 +321,7 @@ obj-microblaze-y = petalogix_s3adsp1800_mmu.o
 obj-microblaze-y += petalogix_ml605_mmu.o
 obj-microblaze-y += microblaze_boot.o
 obj-microblaze-y += spi.o
+obj-microblaze-y += m25p80.o
 
 obj-microblaze-y += microblaze_pic_cpu.o
 obj-microblaze-y += xilinx_intc.o
diff --git a/hw/m25p80.c b/hw/m25p80.c
new file mode 100644
index 0000000..2b67375
--- /dev/null
+++ b/hw/m25p80.c
@@ -0,0 +1,495 @@
+/*
+ * ST M25P80 emulator.
+ *
+ * Copyright (C) 2011 Edgar E. Iglesias <address@hidden>
+ * Copyright (C) 2012 Peter A. G. Crosthwaite <address@hidden>
+ * Copyright (C) 2012 PetaLogix
+ *
+ * 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 2 or
+ * (at your option) version 3 of the License.
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include "hw.h"
+#include "blockdev.h"
+#include "spi.h"
+#include "devices.h"
+
+#ifdef M25P80_ERR_DEBUG
+#define DB_PRINT(...) do { \
+    fprintf(stderr,  ": %s: ", __func__); \
+    fprintf(stderr, ## __VA_ARGS__); \
+    } while (0);
+#else
+    #define DB_PRINT(...)
+#endif
+
+enum FlashCMD {
+    NOP = 0,
+    PP = 0x2,
+    READ = 0x3,
+    WRDI = 0x4,
+    RDSR = 0x5,
+    WREN = 0x6,
+    FAST_READ = 0xb,
+    SECTOR_ERASE = 0x20,
+    BLOCK_ERASE32 = 0x52,
+    JEDEC_READ = 0x9f,
+    CHIP_ERASE = 0xc7,
+};
+
+enum CMDState {
+    STATE_IDLE,
+    STATE_PAGE_PROGRAM,
+    STATE_SECTOR_ERASE,
+    STATE_BLOCK_ERASE32,
+    STATE_READ,
+    STATE_FAST_READ,
+    STATE_COLLECTING_DATA,
+    STATE_READING_DATA,
+};
+
+struct flash {
+    SPISlave spi;
+    SpiSlaveState spi_state;
+    uint32_t r;
+
+    BlockDriverState *bdrv;
+    enum CMDState state;
+
+    uint8_t *storage;
+    uint64_t size;
+    int pagesize;
+    int sectorsize;
+    int blocksize;
+
+    uint8_t data[16];
+    int len;
+    int pos;
+    int wrap_read;
+    int needed_bytes;
+    int next_state;
+
+    int64_t dirty_page;
+
+    uint64_t waddr;
+    int write_enable;
+};
+
+static void flash_sync_page(struct flash *s, int page)
+{
+    if (s->bdrv) {
+        int bdrv_sector;
+        int offset;
+
+        bdrv_sector = (page * s->pagesize) / 512;
+        offset = bdrv_sector * 512;
+        bdrv_write(s->bdrv, bdrv_sector,
+                   s->storage + offset, (s->pagesize + 511) / 512);
+    }
+}
+
+static inline void flash_sync_area(struct flash *s, int64_t off, int64_t len)
+{
+    int64_t start, end;
+
+    if (!s->bdrv) {
+        return;
+    }
+
+    start = off / 512;
+    end = (off + len) / 512;
+    bdrv_write(s->bdrv, start, s->storage + (start * 512), end - start);
+}
+
+static void flash_sector_erase(struct flash *s, int sector)
+{
+    if (!s->write_enable) {
+        DB_PRINT("write with write protect!\n");
+    }
+    memset(s->storage + sector, 0xff, s->sectorsize);
+    flash_sync_area(s, sector, s->sectorsize);
+}
+
+static void flash_block_erase32k(struct flash *s, int addr)
+{
+    if (!s->write_enable) {
+        DB_PRINT("write with write protect!\n");
+    }
+    memset(s->storage + addr, 0xff, 32 * 1024);
+    flash_sync_area(s, addr, 32 * 1024);
+}
+
+static void flash_chip_erase(struct flash *s)
+{
+    if (!s->write_enable) {
+        DB_PRINT("write with write protect!\n");
+    }
+    memset(s->storage, 0xff, s->size);
+    flash_sync_area(s, 0, s->size);
+}
+
+static inline void flash_sync_dirty(struct flash *s, int64_t newpage)
+{
+    if (s->dirty_page >= 0 && s->dirty_page != newpage) {
+        flash_sync_page(s, s->dirty_page);
+        s->dirty_page = newpage;
+    }
+}
+
+static inline
+void flash_write8(struct flash *s, uint64_t addr, uint8_t data)
+{
+    int64_t page = addr / s->pagesize;
+    uint8_t prev = s->storage[s->waddr];
+
+    if (!s->write_enable) {
+        DB_PRINT("write with write protect!\n");
+    }
+
+    if ((prev ^ data) & data) {
+        DB_PRINT("programming zero to one! addr=%lx  %x -> %x\n",
+                  addr, prev, data);
+    }
+    s->storage[s->waddr] ^= ~data & s->storage[s->waddr];
+
+    flash_sync_dirty(s, page);
+    s->dirty_page = page;
+}
+
+static int decode_new_cmd(struct flash *s, uint32_t value)
+{
+    int state = STATE_IDLE;
+    int val;
+
+    switch (value) {
+    case PP:
+        s->needed_bytes = 3;
+        s->pos = 0; s->len = 0;
+        state = STATE_COLLECTING_DATA;
+        s->next_state = STATE_PAGE_PROGRAM;
+        break;
+    case READ:
+        s->needed_bytes = 2;
+        s->pos = 0; s->len = 0;
+        state = STATE_COLLECTING_DATA;
+        s->next_state = STATE_READ;
+        break;
+    case FAST_READ:
+        /* Dummy byte must return data!  */
+        s->needed_bytes = 3;
+        s->pos = 0; s->len = 0;
+        state = STATE_COLLECTING_DATA;
+        s->next_state = STATE_FAST_READ;
+        break;
+    case WRDI:
+        s->write_enable = 0;
+        break;
+    case WREN:
+        s->write_enable = 1;
+        break;
+
+    case RDSR:
+        val = (!!s->write_enable) << 1;
+
+        s->data[0] = val;
+        s->pos = 0; s->len = 1; s->wrap_read = 0;
+        state = STATE_READING_DATA;
+        break;
+
+    case JEDEC_READ:
+        s->data[0] = 0xef;
+        s->data[1] = 0x40;
+        s->data[2] = 0x17;
+        s->pos = 0;
+        s->len = 3;
+        s->wrap_read = 0;
+        state = STATE_READING_DATA;
+        break;
+
+    case SECTOR_ERASE:
+        s->needed_bytes = 2;
+        s->pos = 0; s->len = 0;
+        state = STATE_COLLECTING_DATA;
+        s->next_state = STATE_SECTOR_ERASE;
+        break;
+
+    case BLOCK_ERASE32:
+        s->needed_bytes = 2;
+        s->pos = 0; s->len = 0;
+        state = STATE_COLLECTING_DATA;
+        s->next_state = STATE_BLOCK_ERASE32;
+        break;
+
+    case CHIP_ERASE:
+        if (s->write_enable) {
+            DB_PRINT("chip erase\n");
+            flash_chip_erase(s);
+        } else {
+            DB_PRINT("chip erase with write protect!\n");
+        }
+        break;
+    case NOP:
+        break;
+    default:
+        DB_PRINT("Unknown cmd %x\n", value);
+        break;
+    }
+
+    return state;
+}
+
+static void sector_erase(struct flash *s, uint32_t data)
+{
+    int sector;
+
+    if (s->next_state == STATE_SECTOR_ERASE) {
+        /* Transition just happened, pick up the address.  */
+        sector = s->data[0] << 16;
+        sector |= s->data[1] << 8;
+        sector |= data;
+        s->next_state = STATE_IDLE;
+    }
+    DB_PRINT("sector_erase sector=%d\n", sector);
+    flash_sector_erase(s, sector);
+}
+
+static void block_erase32(struct flash *s, uint32_t data)
+{
+    int addr;
+
+    if (s->next_state == STATE_BLOCK_ERASE32) {
+        /* Transition just happened, pick up the address.  */
+        addr = s->data[0] << 16;
+        addr |= s->data[1] << 8;
+        addr |= data;
+        s->next_state = STATE_IDLE;
+    }
+    DB_PRINT("block_erase addr=%08x\n", addr);
+    flash_block_erase32k(s, addr);
+}
+
+static void page_program(struct flash *s, uint32_t data)
+{
+    if (s->next_state == STATE_PAGE_PROGRAM) {
+        /* Transition just happened, pick up the address.  */
+        s->waddr = s->data[0] << 16;
+        s->waddr |= s->data[1] << 8;
+        s->waddr |= s->data[2];
+        s->next_state = STATE_IDLE;
+    }
+    DB_PRINT("page program waddr=%lx data=%x\n", s->waddr, data);
+    flash_write8(s, s->waddr, data);
+    s->waddr++;
+}
+
+/* FIXME: these two functions are near identical, merge */
+
+static void state_read(struct flash *s, uint32_t data)
+{
+    int addr;
+
+    if (s->next_state == STATE_READ) {
+        /* Transition just happened, pick up the address.  */
+        s->waddr = s->data[0] << 16;
+        s->waddr |= s->data[1] << 8;
+        s->waddr |= data;
+        s->next_state = STATE_IDLE;
+        s->spi_state = SPI_IDLE;
+    }
+    addr = s->waddr;
+    s->r = s->storage[addr];
+    DB_PRINT("READ 0x%lx.0x%x=%x\n", s->waddr, addr, s->r);
+    addr += 1;
+    if (addr >= s->size) {
+        addr = 0;
+    }
+    s->waddr = addr;
+    s->spi_state = SPI_DATA_PENDING;
+}
+
+static void state_fast_read(struct flash *s, uint32_t data)
+{
+    int addr;
+
+    if (s->next_state == STATE_FAST_READ) {
+        /* Transition just happened, pick up the address.  */
+        s->waddr = s->data[0] << 16;
+        s->waddr |= s->data[1] << 8;
+        s->waddr |= s->data[2];
+        if (s->data[3] != 0) {
+            hw_error("Fast read dummy byte=%x\n", s->data[3]);
+        }
+        s->next_state = STATE_IDLE;
+        s->spi_state = SPI_IDLE;
+    }
+
+    addr = s->waddr;
+    s->r = s->storage[addr];
+    DB_PRINT("FAST-READ 0x%lx.0x%x=%x\n", s->waddr, addr, s->r);
+    addr += 1;
+    if (addr >= s->size) {
+        addr = 0;
+    }
+    s->waddr = addr;
+    s->spi_state = SPI_DATA_PENDING;
+}
+
+static void m25p80_cs(SPISlave *ss, uint8_t select)
+{
+    struct flash *s = FROM_SPI_SLAVE(struct flash, ss);
+
+    if (!select) {
+        s->len = 0;
+        s->pos = 0;
+        s->state = STATE_IDLE;
+        s->next_state = STATE_IDLE;
+        flash_sync_dirty(s, -1);
+        DB_PRINT("deselect\n");
+        s->spi_state = SPI_NO_CS;
+    } else {
+        s->spi_state = SPI_IDLE;
+    }
+}
+
+static SpiSlaveState m25p80_send(SPISlave *ss, uint32_t value, int len)
+{
+    struct flash *s = FROM_SPI_SLAVE(struct flash, ss);
+
+    switch (s->state) {
+    case STATE_PAGE_PROGRAM:
+        page_program(s, value);
+        break;
+
+    case STATE_READ:
+        state_read(s, value);
+        break;
+
+    case STATE_FAST_READ:
+        state_fast_read(s, value);
+        break;
+
+    case STATE_SECTOR_ERASE:
+        sector_erase(s, value);
+        break;
+
+    case STATE_BLOCK_ERASE32:
+        block_erase32(s, value);
+        break;
+
+    case STATE_COLLECTING_DATA:
+        if (len > 0) {
+            s->data[s->len] = value;
+            s->len++;
+
+            if (s->len == s->needed_bytes) {
+                s->state = s->next_state;
+            }
+        }
+        break;
+
+    case STATE_READING_DATA:
+        s->r = s->data[s->pos];
+        s->spi_state = SPI_DATA_PENDING;
+        s->pos++;
+        if (s->pos == s->len) {
+            s->pos = 0;
+            if (!s->wrap_read) {
+                s->state = STATE_IDLE;
+            }
+        }
+        break;
+
+    default:
+    case STATE_IDLE:
+        if (len > 0) {
+            s->state = decode_new_cmd(s, value);
+        }
+        break;
+    }
+    return s->spi_state;
+}
+
+static SpiSlaveState m25p80_recv(SPISlave *ss, uint32_t *data)
+{
+    struct flash *s = FROM_SPI_SLAVE(struct flash, ss);
+
+    *data = s->r;
+    s->spi_state = SPI_IDLE;
+    return SPI_IDLE;
+}
+
+static SpiSlaveState m25p80_get_state(SPISlave *ss)
+{
+    struct flash *s = FROM_SPI_SLAVE(struct flash, ss);
+
+    return s->spi_state;
+}
+
+static int m25p80_init(SPISlave *ss)
+{
+    DriveInfo *dinfo;
+    struct flash *s = FROM_SPI_SLAVE(struct flash, ss);
+    /* FIXME: This should be handled centrally!  */
+    static int mtdblock_idx;
+    dinfo = drive_get(IF_MTD, 0, mtdblock_idx++);
+
+    DB_PRINT("inited m25p80 device model - dinfo = %p\n", dinfo);
+    /* TODO: parameterize */
+    s->size = 8 * 1024 * 1024;
+    s->pagesize = 256;
+    s->sectorsize = 4 * 1024;
+    s->dirty_page = -1;
+    s->storage = g_malloc0(s->size);
+
+    if (dinfo && dinfo->bdrv) {
+        int rsize;
+
+        s->bdrv = dinfo->bdrv;
+        rsize = MIN(bdrv_getlength(s->bdrv), s->size);
+        if (bdrv_read(s->bdrv, 0, s->storage, (s->size + 511) / 512)) {
+            fprintf(stderr, "Failed to initialize SPI flash!\n");
+            return 1;
+        }
+    } else {
+        s->write_enable = 1;
+        flash_chip_erase(s);
+        s->write_enable = 0;
+    }
+
+    return 0;
+}
+
+static void m25p80_class_init(ObjectClass *klass, void *data)
+{
+    SPISlaveClass *k = SPI_SLAVE_CLASS(klass);
+
+    k->init = m25p80_init;
+    k->send = m25p80_send;
+    k->recv = m25p80_recv;
+    k->cs = m25p80_cs;
+    k->get_state = m25p80_get_state;
+}
+
+static TypeInfo m25p80_info = {
+    .name           = "m25p80",
+    .parent         = TYPE_SPI_SLAVE,
+    .instance_size  = sizeof(struct flash),
+    .class_init     = m25p80_class_init,
+};
+
+static void m25p80_register_types(void)
+{
+    type_register_static(&m25p80_info);
+}
+
+type_init(m25p80_register_types)
-- 
1.7.3.2