[U-Boot] [PATCH 4/5 v2] sandbox: new SPI flash driver
Mike Frysinger
vapier at gentoo.org
Tue Jan 31 20:53:33 CET 2012
This adds a SPI flash driver which simulates SPI flash clients.
Currently supports the bare min that U-Boot requires: you can
probe, read, erase, and write. Should be easy to extend to make
it behave more exactly like a real SPI flash, but this is good
enough to merge now.
Signed-off-by: Mike Frysinger <vapier at gentoo.org>
---
drivers/mtd/spi/Makefile | 1 +
drivers/mtd/spi/sandbox.c | 386 +++++++++++++++++++++++++++++++++++++++++++++
drivers/spi/sandbox_spi.c | 5 +
3 files changed, 392 insertions(+), 0 deletions(-)
create mode 100644 drivers/mtd/spi/sandbox.c
diff --git a/drivers/mtd/spi/Makefile b/drivers/mtd/spi/Makefile
index 90f8392..fb37807 100644
--- a/drivers/mtd/spi/Makefile
+++ b/drivers/mtd/spi/Makefile
@@ -33,6 +33,7 @@ COBJS-$(CONFIG_SPI_FLASH) += spi_flash.o
COBJS-$(CONFIG_SPI_FLASH_ATMEL) += atmel.o
COBJS-$(CONFIG_SPI_FLASH_EON) += eon.o
COBJS-$(CONFIG_SPI_FLASH_MACRONIX) += macronix.o
+COBJS-$(CONFIG_SPI_FLASH_SANDBOX) += sandbox.o
COBJS-$(CONFIG_SPI_FLASH_SPANSION) += spansion.o
COBJS-$(CONFIG_SPI_FLASH_SST) += sst.o
COBJS-$(CONFIG_SPI_FLASH_STMICRO) += stmicro.o
diff --git a/drivers/mtd/spi/sandbox.c b/drivers/mtd/spi/sandbox.c
new file mode 100644
index 0000000..4b8e384
--- /dev/null
+++ b/drivers/mtd/spi/sandbox.c
@@ -0,0 +1,386 @@
+/*
+ * Simulate a SPI flash
+ *
+ * Copyright (c) 2011-2012 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+#include <os.h>
+
+#include <spi_flash.h>
+#include "spi_flash_internal.h"
+
+#include <asm/spi.h>
+
+/*
+ * The different states that our SPI flash transitions between.
+ * We need to keep track of this across multiple xfer calls since
+ * the SPI bus could possibly call down into us multiple times.
+ */
+typedef enum {
+ SF_CMD, /* default state -- we're awaiting a command */
+ SF_ID, /* read the flash's (jedec) ID code */
+ SF_ADDR, /* processing the offset in the flash to read/etc... */
+ SF_READ, /* reading data from the flash */
+ SF_WRITE, /* writing data to the flash, i.e. page programming */
+ SF_ERASE, /* erase the flash */
+ SF_READ_STATUS, /* read the flash's status register */
+} sb_sf_state;
+
+static const char *sb_sf_state_name(sb_sf_state state)
+{
+ static const char * const states[] = {
+ "CMD", "ID", "ADDR", "READ", "WRITE", "ERASE", "READ_STATUS",
+ };
+ return states[state];
+}
+
+/* Bits for the status register */
+#define STAT_WIP (1 << 0)
+#define STAT_WEL (1 << 1)
+
+/* Assume all SPI flashes have 3 byte addresses since they do atm */
+#define SF_ADDR_LEN 3
+
+struct sb_spi_flash_erase_commands {
+ u8 cmd;
+ u32 size;
+};
+#define IDCODE_LEN 5
+#define MAX_ERASE_CMDS 2
+struct sb_spi_flash_data {
+ const char *name;
+ u8 idcode[IDCODE_LEN];
+ u32 size;
+ const struct sb_spi_flash_erase_commands erase_cmds[MAX_ERASE_CMDS];
+};
+
+/* Structure describing all the flashes we know how to emulate */
+static const struct sb_spi_flash_data sb_sf_flashes[] = {
+ {
+ "M25P16", { 0x20, 0x20, 0x15 }, (2 * 1024 * 1024),
+ { /* erase commands */
+ { 0xd8, (64 * 1024), }, /* sector */
+ { 0xc7, (2 * 1024 * 1024), }, /* bulk */
+ },
+ },
+};
+
+/* Used to quickly bulk erase backing store */
+static u8 sb_sf_0xff[0x10000];
+
+/* Internal state data for each SPI flash */
+struct sb_spi_flash {
+ /*
+ * As we receive data over the SPI bus, our flash transitions
+ * between states. For example, we start off in the SF_CMD
+ * state where the first byte tells us what operation to perform
+ * (such as read or write the flash). But the operation itself
+ * can go through a few states such as first reading in the
+ * offset in the flash to perform the requested operation.
+ * Thus "state" stores the exact state that our machine is in
+ * while "cmd" stores the overall command we're processing.
+ */
+ sb_sf_state state;
+ uint cmd;
+ const void *cmd_data;
+ /* Current position in the flash; used when reading/writing/etc... */
+ uint off;
+ /* How many address bytes we've consumed */
+ uint addr_bytes, pad_addr_bytes;
+ /* The current flash status (see STAT_XXX defines above) */
+ u8 status;
+ /* Data describing the flash we're emulating */
+ const struct sb_spi_flash_data *data;
+ /* The file on disk to serv up data from */
+ int fd;
+};
+
+static int sb_sf_setup(void **priv, const char *spec)
+{
+ /* spec = idcode:file */
+ struct sb_spi_flash *sbsf;
+ const char *file;
+ size_t i, len, idname_len;
+ const struct sb_spi_flash_data *data;
+
+ file = strchr(spec, ':');
+ if (!file)
+ goto error;
+ idname_len = file - spec;
+ ++file;
+
+ for (i = 0; i < ARRAY_SIZE(sb_sf_flashes); ++i) {
+ data = &sb_sf_flashes[i];
+ len = strlen(data->name);
+ if (idname_len != len)
+ continue;
+ if (!memcmp(spec, data->name, len))
+ break;
+ }
+ if (i == ARRAY_SIZE(sb_sf_flashes)) {
+ printf("sb_sf: unknown flash '%*s'\n",
+ (int)idname_len, file);
+ goto error;
+ }
+
+ if (sb_sf_0xff[0] == 0x00)
+ memset(sb_sf_0xff, 0xff, sizeof(sb_sf_0xff));
+
+ sbsf = malloc(sizeof(*sbsf));
+ if (!sbsf)
+ goto error;
+
+ sbsf->fd = os_open(file, 02);
+ if (sbsf->fd == -1) {
+ free(sbsf);
+ goto error;
+ }
+
+ sbsf->data = data;
+
+ *priv = sbsf;
+ return 0;
+
+ error:
+ printf("sb_sf: unable to parse client spec\n");
+ return 1;
+}
+
+static void sb_sf_free(void *priv)
+{
+ struct sb_spi_flash *sbsf = priv;
+
+ os_close(sbsf->fd);
+ free(sbsf);
+}
+
+static void sb_sf_cs_activate(void *priv)
+{
+ struct sb_spi_flash *sbsf = priv;
+
+ debug("sb_sf: CS activated; state is fresh!\n");
+
+ /* CS is asserted, so reset state */
+ sbsf->off = 0;
+ sbsf->addr_bytes = 0;
+ sbsf->pad_addr_bytes = 0;
+ sbsf->state = sbsf->cmd = SF_CMD;
+}
+
+static void sb_sf_cs_deactivate(void *priv)
+{
+ debug("sb_sf: CS deactivated; cmd done processing!\n");
+}
+
+/* Figure out what command this stream is telling us to do */
+static int sb_sf_process_cmd(struct sb_spi_flash *sbsf, const u8 *rx, u8 *tx)
+{
+ sb_sf_state oldstate = sbsf->state;
+
+ /* We need to output a byte for the cmd byte we just ate */
+ sb_spi_tristate(tx, 1);
+
+ sbsf->cmd = rx[0];
+ switch (sbsf->cmd) {
+ case CMD_READ_ID:
+ sbsf->state = sbsf->cmd = SF_ID;
+ break;
+ case CMD_READ_ARRAY_FAST:
+ sbsf->pad_addr_bytes = 1;
+ case CMD_READ_ARRAY_SLOW:
+ case CMD_PAGE_PROGRAM:
+ state_addr:
+ sbsf->state = SF_ADDR;
+ break;
+ case CMD_WRITE_DISABLE:
+ debug(" write disabled\n");
+ sbsf->status &= ~STAT_WEL;
+ break;
+ case CMD_READ_STATUS:
+ sbsf->state = SF_READ_STATUS;
+ break;
+ case CMD_WRITE_ENABLE:
+ debug(" write enabled\n");
+ sbsf->status |= STAT_WEL;
+ break;
+ default: {
+ size_t i;
+
+ /* handle erase commands first */
+ for (i = 0; i < MAX_ERASE_CMDS; ++i) {
+ const struct sb_spi_flash_erase_commands *erase_cmd =
+ &sbsf->data->erase_cmds[i];
+
+ if (erase_cmd->cmd == 0x00)
+ continue;
+ if (sbsf->cmd != erase_cmd->cmd)
+ continue;
+
+ sbsf->cmd_data = erase_cmd;
+ goto state_addr;
+ }
+
+ debug(" cmd unknown: %#x\n", sbsf->cmd);
+ return 1;
+ }
+ }
+
+ if (oldstate != sbsf->state)
+ debug(" cmd: transition to %s state\n",
+ sb_sf_state_name(sbsf->state));
+
+ return 0;
+}
+
+static int sb_sf_xfer(void *priv, const u8 *rx, u8 *tx,
+ uint bytes)
+{
+ struct sb_spi_flash *sbsf = priv;
+ uint cnt, pos = 0;
+
+ debug("sb_sf: state:%x(%s) bytes:%u\n", sbsf->state,
+ sb_sf_state_name(sbsf->state), bytes);
+
+ if (sbsf->state == SF_CMD) {
+ /* Figure out the initial state */
+ if (sb_sf_process_cmd(sbsf, rx, tx))
+ return 1;
+ ++pos;
+ }
+
+ /* Process the remaining data */
+ while (pos < bytes) {
+ switch (sbsf->state) {
+ case SF_ID: {
+ u8 id;
+
+ debug(" id: off:%u tx:", sbsf->off);
+ if (sbsf->off < IDCODE_LEN)
+ id = sbsf->data->idcode[sbsf->off];
+ else
+ id = 0;
+ debug("%02x\n", id);
+ tx[pos++] = id;
+ ++sbsf->off;
+ break;
+ }
+ case SF_ADDR:
+ debug(" addr: bytes:%u rx:%02x ",
+ sbsf->addr_bytes, rx[pos]);
+
+ if (sbsf->addr_bytes++ < SF_ADDR_LEN)
+ sbsf->off = (sbsf->off << 8) | rx[pos];
+ debug("addr:%06x\n", sbsf->off);
+
+ sb_spi_tristate(&tx[pos++], 1);
+
+ /* See if we're done processing */
+ if (sbsf->addr_bytes < SF_ADDR_LEN + sbsf->pad_addr_bytes)
+ break;
+
+ /* Next state! */
+ os_lseek(sbsf->fd, sbsf->off, OS_SEEK_SET);
+ switch (sbsf->cmd) {
+ case CMD_READ_ARRAY_FAST:
+ case CMD_READ_ARRAY_SLOW:
+ sbsf->state = SF_READ;
+ break;
+ case CMD_PAGE_PROGRAM:
+ sbsf->state = SF_WRITE;
+ break;
+ default:
+ /* assume erase state ... */
+ sbsf->state = SF_ERASE;
+ goto case_SF_ERASE;
+ }
+ debug(" cmd: transition to %s state\n",
+ sb_sf_state_name(sbsf->state));
+ break;
+ case SF_READ:
+ /*
+ * XXX: need to handle exotic behavior:
+ * - reading past end of device
+ */
+
+ cnt = bytes - pos;
+ debug(" tx: read(%u)\n", cnt);
+ pos += os_read(sbsf->fd, tx + pos, cnt);
+ break;
+ case SF_READ_STATUS:
+ debug(" read status: %#x\n", sbsf->status);
+ cnt = bytes - pos;
+ memset(tx + pos, sbsf->status, cnt);
+ pos += cnt;
+ break;
+ case SF_WRITE:
+ /*
+ * XXX: need to handle exotic behavior:
+ * - unaligned addresses
+ * - more than a page (256) worth of data
+ * - reading past end of device
+ */
+
+ if (!(sbsf->status & STAT_WEL)) {
+ puts("sb_sf: write enable not set before erase\n");
+ goto done;
+ }
+
+ cnt = bytes - pos;
+ debug(" rx: write(%u)\n", cnt);
+ sb_spi_tristate(&tx[pos], cnt);
+ pos += os_write(sbsf->fd, rx + pos, cnt);
+ sbsf->status &= ~STAT_WEL;
+ break;
+ case SF_ERASE:
+ case_SF_ERASE: {
+ const struct sb_spi_flash_erase_commands *erase_cmd =
+ sbsf->cmd_data;
+
+ if (!(sbsf->status & STAT_WEL)) {
+ puts("sb_sf: write enable not set before erase\n");
+ goto done;
+ }
+
+ /* verify address is aligned */
+ if (sbsf->off & ~(erase_cmd->size - 1)) {
+ debug(" sector erase: cmd:%#x needs align:%#x, but we got %#x\n",
+ erase_cmd->cmd, erase_cmd->size, sbsf->off);
+ sbsf->status &= ~STAT_WEL;
+ goto done;
+ }
+
+ debug(" sector erase addr: %u\n", sbsf->off);
+
+ cnt = bytes - pos;
+ sb_spi_tristate(&tx[pos], cnt);
+ pos += cnt;
+
+ /* XXX: latch WIP in status, and delay before clearing it ? */
+ os_write(sbsf->fd, sb_sf_0xff, erase_cmd->size);
+ sbsf->status &= ~STAT_WEL;
+ goto done;
+ }
+ default:
+ debug(" ??? no idea what to do ???\n");
+ goto done;
+ }
+ }
+
+ done:
+ return pos == bytes ? 0 : 1;
+}
+
+const struct sb_spi_emu_ops sb_sf_ops = {
+ .setup = sb_sf_setup,
+ .free = sb_sf_free,
+ .cs_activate = sb_sf_cs_activate,
+ .cs_deactivate = sb_sf_cs_deactivate,
+ .xfer = sb_sf_xfer,
+};
diff --git a/drivers/spi/sandbox_spi.c b/drivers/spi/sandbox_spi.c
index d0cba76..88b51ab 100644
--- a/drivers/spi/sandbox_spi.c
+++ b/drivers/spi/sandbox_spi.c
@@ -35,10 +35,15 @@ static const char *sb_lookup_arg(unsigned int bus, unsigned int cs)
return os_getopt(sf_arg, 1);
}
+extern const struct sb_spi_emu_ops sb_sf_ops;
+
static const struct {
const char *spec;
const struct sb_spi_emu_ops *ops;
} sb_emu_map[] = {
+#ifdef CONFIG_SPI_FLASH_SANDBOX
+ { "sf", &sb_sf_ops, },
+#endif
};
static int sb_parse_type(struct sb_spi_slave *sss)
--
1.7.8.4
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