u-boot/drivers/misc/i2c_eeprom_emul.c
Simon Glass 6ec1b75358 dm: i2c: Add an I2C EEPROM simulator
To enable testing of I2C, add a simple I2C EEPROM simulator for sandbox.
It supports reading and writing from a small data store.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-12-11 13:18:42 -07:00

169 lines
4.1 KiB
C

/*
* Simulate an I2C eeprom
*
* Copyright (c) 2014 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <i2c.h>
#include <malloc.h>
#include <asm/test.h>
#ifdef DEBUG
#define debug_buffer print_buffer
#else
#define debug_buffer(x, ...)
#endif
DECLARE_GLOBAL_DATA_PTR;
struct sandbox_i2c_flash_plat_data {
enum sandbox_i2c_eeprom_test_mode test_mode;
const char *filename;
int offset_len; /* Length of an offset in bytes */
int size; /* Size of data buffer */
};
struct sandbox_i2c_flash {
uint8_t *data;
};
void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
enum sandbox_i2c_eeprom_test_mode mode)
{
struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
plat->test_mode = mode;
}
void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len)
{
struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
plat->offset_len = offset_len;
}
static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
int nmsgs)
{
struct sandbox_i2c_flash *priv = dev_get_priv(emul);
uint offset = 0;
debug("\n%s\n", __func__);
debug_buffer(0, priv->data, 1, 16, 0);
for (; nmsgs > 0; nmsgs--, msg++) {
struct sandbox_i2c_flash_plat_data *plat =
dev_get_platdata(emul);
int len;
u8 *ptr;
if (!plat->size)
return -ENODEV;
if (msg->addr + msg->len > plat->size) {
debug("%s: Address %x, len %x is outside range 0..%x\n",
__func__, msg->addr, msg->len, plat->size);
return -EINVAL;
}
len = msg->len;
debug(" %s: msg->len=%d",
msg->flags & I2C_M_RD ? "read" : "write",
msg->len);
if (msg->flags & I2C_M_RD) {
if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
len = 1;
debug(", offset %x, len %x: ", offset, len);
memcpy(msg->buf, priv->data + offset, len);
memset(msg->buf + len, '\xff', msg->len - len);
debug_buffer(0, msg->buf, 1, msg->len, 0);
} else if (len >= plat->offset_len) {
int i;
ptr = msg->buf;
for (i = 0; i < plat->offset_len; i++, len--)
offset = (offset << 8) | *ptr++;
debug(", set offset %x: ", offset);
debug_buffer(0, msg->buf, 1, msg->len, 0);
if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
len = min(len, 1);
/* For testing, map offsets into our limited buffer */
for (i = 24; i > 0; i -= 8) {
if (offset > (1 << i)) {
offset = (offset >> i) |
(offset & ((1 << i) - 1));
offset += i;
}
}
memcpy(priv->data + offset, ptr, len);
}
}
debug_buffer(0, priv->data, 1, 16, 0);
return 0;
}
struct dm_i2c_ops sandbox_i2c_emul_ops = {
.xfer = sandbox_i2c_eeprom_xfer,
};
static int sandbox_i2c_eeprom_ofdata_to_platdata(struct udevice *dev)
{
struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
plat->size = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
"sandbox,size", 32);
plat->filename = fdt_getprop(gd->fdt_blob, dev->of_offset,
"sandbox,filename", NULL);
if (!plat->filename) {
debug("%s: No filename for device '%s'\n", __func__,
dev->name);
return -EINVAL;
}
plat->test_mode = SIE_TEST_MODE_NONE;
plat->offset_len = 1;
return 0;
}
static int sandbox_i2c_eeprom_probe(struct udevice *dev)
{
struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
struct sandbox_i2c_flash *priv = dev_get_priv(dev);
priv->data = calloc(1, plat->size);
if (!priv->data)
return -ENOMEM;
return 0;
}
static int sandbox_i2c_eeprom_remove(struct udevice *dev)
{
struct sandbox_i2c_flash *priv = dev_get_priv(dev);
free(priv->data);
return 0;
}
static const struct udevice_id sandbox_i2c_ids[] = {
{ .compatible = "sandbox,i2c-eeprom" },
{ }
};
U_BOOT_DRIVER(sandbox_i2c_emul) = {
.name = "sandbox_i2c_eeprom_emul",
.id = UCLASS_I2C_EMUL,
.of_match = sandbox_i2c_ids,
.ofdata_to_platdata = sandbox_i2c_eeprom_ofdata_to_platdata,
.probe = sandbox_i2c_eeprom_probe,
.remove = sandbox_i2c_eeprom_remove,
.priv_auto_alloc_size = sizeof(struct sandbox_i2c_flash),
.platdata_auto_alloc_size = sizeof(struct sandbox_i2c_flash_plat_data),
.ops = &sandbox_i2c_emul_ops,
};