u-boot/drivers/mtd/spi/sandbox.c
Mike Frysinger ffdb20bea1 sandbox: spi: Add new SPI flash driver
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.

sjg@chromium.org added a README and tidied up code a little.
Added a required map_sysmem() for sandbox.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
2013-12-09 12:22:39 -07:00

483 lines
11 KiB
C

/*
* Simulate a SPI flash
*
* Copyright (c) 2011-2013 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 "sf_internal.h"
#include <asm/getopt.h>
#include <asm/spi.h>
#include <asm/state.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.
*/
enum sandbox_sf_state {
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 */
SF_READ_STATUS1, /* read the flash's status register upper 8 bits*/
};
static const char *sandbox_sf_state_name(enum sandbox_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 sandbox_spi_flash_erase_commands {
u8 cmd;
u32 size;
};
#define IDCODE_LEN 5
#define MAX_ERASE_CMDS 3
struct sandbox_spi_flash_data {
const char *name;
u8 idcode[IDCODE_LEN];
u32 size;
const struct sandbox_spi_flash_erase_commands
erase_cmds[MAX_ERASE_CMDS];
};
/* Structure describing all the flashes we know how to emulate */
static const struct sandbox_spi_flash_data sandbox_sf_flashes[] = {
{
"M25P16", { 0x20, 0x20, 0x15 }, (2 << 20),
{ /* erase commands */
{ 0xd8, (64 << 10), }, /* sector */
{ 0xc7, (2 << 20), }, /* bulk */
},
},
{
"W25Q32", { 0xef, 0x40, 0x16 }, (4 << 20),
{ /* erase commands */
{ 0x20, (4 << 10), }, /* 4KB */
{ 0xd8, (64 << 10), }, /* sector */
{ 0xc7, (4 << 20), }, /* bulk */
},
},
{
"W25Q128", { 0xef, 0x40, 0x18 }, (16 << 20),
{ /* erase commands */
{ 0x20, (4 << 10), }, /* 4KB */
{ 0xd8, (64 << 10), }, /* sector */
{ 0xc7, (16 << 20), }, /* bulk */
},
},
};
/* Used to quickly bulk erase backing store */
static u8 sandbox_sf_0xff[0x1000];
/* Internal state data for each SPI flash */
struct sandbox_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.
*/
enum sandbox_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) */
u16 status;
/* Data describing the flash we're emulating */
const struct sandbox_spi_flash_data *data;
/* The file on disk to serv up data from */
int fd;
};
static int sandbox_sf_setup(void **priv, const char *spec)
{
/* spec = idcode:file */
struct sandbox_spi_flash *sbsf;
const char *file;
size_t i, len, idname_len;
const struct sandbox_spi_flash_data *data;
file = strchr(spec, ':');
if (!file) {
printf("sandbox_sf: unable to parse file\n");
goto error;
}
idname_len = file - spec;
++file;
for (i = 0; i < ARRAY_SIZE(sandbox_sf_flashes); ++i) {
data = &sandbox_sf_flashes[i];
len = strlen(data->name);
if (idname_len != len)
continue;
if (!memcmp(spec, data->name, len))
break;
}
if (i == ARRAY_SIZE(sandbox_sf_flashes)) {
printf("sandbox_sf: unknown flash '%*s'\n", (int)idname_len,
spec);
goto error;
}
if (sandbox_sf_0xff[0] == 0x00)
memset(sandbox_sf_0xff, 0xff, sizeof(sandbox_sf_0xff));
sbsf = calloc(sizeof(*sbsf), 1);
if (!sbsf) {
printf("sandbox_sf: out of memory\n");
goto error;
}
sbsf->fd = os_open(file, 02);
if (sbsf->fd == -1) {
free(sbsf);
printf("sandbox_sf: unable to open file '%s'\n", file);
goto error;
}
sbsf->data = data;
*priv = sbsf;
return 0;
error:
return 1;
}
static void sandbox_sf_free(void *priv)
{
struct sandbox_spi_flash *sbsf = priv;
os_close(sbsf->fd);
free(sbsf);
}
static void sandbox_sf_cs_activate(void *priv)
{
struct sandbox_spi_flash *sbsf = priv;
debug("sandbox_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 = SF_CMD;
sbsf->cmd = SF_CMD;
}
static void sandbox_sf_cs_deactivate(void *priv)
{
debug("sandbox_sf: CS deactivated; cmd done processing!\n");
}
/* Figure out what command this stream is telling us to do */
static int sandbox_sf_process_cmd(struct sandbox_spi_flash *sbsf, const u8 *rx,
u8 *tx)
{
enum sandbox_sf_state oldstate = sbsf->state;
/* We need to output a byte for the cmd byte we just ate */
sandbox_spi_tristate(tx, 1);
sbsf->cmd = rx[0];
switch (sbsf->cmd) {
case CMD_READ_ID:
sbsf->state = SF_ID;
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_READ_STATUS1:
sbsf->state = SF_READ_STATUS1;
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 sandbox_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",
sandbox_sf_state_name(sbsf->state));
return 0;
}
int sandbox_erase_part(struct sandbox_spi_flash *sbsf, int size)
{
int todo;
int ret;
while (size > 0) {
todo = min(size, sizeof(sandbox_sf_0xff));
ret = os_write(sbsf->fd, sandbox_sf_0xff, todo);
if (ret != todo)
return ret;
size -= todo;
}
return 0;
}
static int sandbox_sf_xfer(void *priv, const u8 *rx, u8 *tx,
uint bytes)
{
struct sandbox_spi_flash *sbsf = priv;
uint cnt, pos = 0;
int ret;
debug("sandbox_sf: state:%x(%s) bytes:%u\n", sbsf->state,
sandbox_sf_state_name(sbsf->state), bytes);
if (sbsf->state == SF_CMD) {
/* Figure out the initial state */
if (sandbox_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);
sandbox_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! */
if (os_lseek(sbsf->fd, sbsf->off, OS_SEEK_SET) < 0) {
puts("sandbox_sf: os_lseek() failed");
return 1;
}
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",
sandbox_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);
ret = os_read(sbsf->fd, tx + pos, cnt);
if (ret < 0) {
puts("sandbox_spi: os_read() failed\n");
return 1;
}
pos += ret;
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_READ_STATUS1:
debug(" read status: %#x\n", sbsf->status);
cnt = bytes - pos;
memset(tx + pos, sbsf->status >> 8, 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("sandbox_sf: write enable not set before write\n");
goto done;
}
cnt = bytes - pos;
debug(" rx: write(%u)\n", cnt);
sandbox_spi_tristate(&tx[pos], cnt);
ret = os_write(sbsf->fd, rx + pos, cnt);
if (ret < 0) {
puts("sandbox_spi: os_write() failed\n");
return 1;
}
pos += ret;
sbsf->status &= ~STAT_WEL;
break;
case SF_ERASE:
case_sf_erase: {
const struct sandbox_spi_flash_erase_commands *
erase_cmd = sbsf->cmd_data;
if (!(sbsf->status & STAT_WEL)) {
puts("sandbox_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;
sandbox_spi_tristate(&tx[pos], cnt);
pos += cnt;
/*
* TODO(vapier@gentoo.org): latch WIP in status, and
* delay before clearing it ?
*/
ret = sandbox_erase_part(sbsf, erase_cmd->size);
sbsf->status &= ~STAT_WEL;
if (ret) {
debug("sandbox_sf: Erase failed\n");
goto done;
}
goto done;
}
default:
debug(" ??? no idea what to do ???\n");
goto done;
}
}
done:
return pos == bytes ? 0 : 1;
}
static const struct sandbox_spi_emu_ops sandbox_sf_ops = {
.setup = sandbox_sf_setup,
.free = sandbox_sf_free,
.cs_activate = sandbox_sf_cs_activate,
.cs_deactivate = sandbox_sf_cs_deactivate,
.xfer = sandbox_sf_xfer,
};
static int sandbox_cmdline_cb_spi_sf(struct sandbox_state *state,
const char *arg)
{
unsigned long bus, cs;
const char *spec = sandbox_spi_parse_spec(arg, &bus, &cs);
if (!spec)
return 1;
/*
* It is safe to not make a copy of 'spec' because it comes from the
* command line.
*
* TODO(sjg@chromium.org): It would be nice if we could parse the
* spec here, but the problem is that no U-Boot init has been done
* yet. Perhaps we can figure something out.
*/
state->spi[bus][cs].ops = &sandbox_sf_ops;
state->spi[bus][cs].spec = spec;
return 0;
}
SANDBOX_CMDLINE_OPT(spi_sf, 1, "connect a SPI flash: <bus>:<cs>:<id>:<file>");