u-boot/drivers/i2c/sandbox_i2c.c

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/*
* Simulate an I2C port
*
* Copyright (c) 2014 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <i2c.h>
#include <asm/test.h>
#include <dm/lists.h>
#include <dm/device-internal.h>
DECLARE_GLOBAL_DATA_PTR;
struct sandbox_i2c_priv {
bool test_mode;
};
static int get_emul(struct udevice *dev, struct udevice **devp,
struct dm_i2c_ops **opsp)
{
struct dm_i2c_chip *plat;
struct udevice *child;
int ret;
*devp = NULL;
*opsp = NULL;
plat = dev_get_parent_platdata(dev);
if (!plat->emul) {
ret = dm_scan_fdt_dev(dev);
if (ret)
return ret;
for (device_find_first_child(dev, &child); child;
device_find_next_child(&child)) {
if (device_get_uclass_id(child) != UCLASS_I2C_EMUL)
continue;
ret = device_probe(child);
if (ret)
return ret;
break;
}
if (child)
plat->emul = child;
else
return -ENODEV;
}
*devp = plat->emul;
*opsp = i2c_get_ops(plat->emul);
return 0;
}
void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode)
{
struct sandbox_i2c_priv *priv = dev_get_priv(bus);
priv->test_mode = test_mode;
}
static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
int nmsgs)
{
struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
struct sandbox_i2c_priv *priv = dev_get_priv(bus);
struct dm_i2c_ops *ops;
struct udevice *emul, *dev;
bool is_read;
int ret;
/* Special test code to return success but with no emulation */
if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR)
return 0;
ret = i2c_get_chip(bus, msg->addr, 1, &dev);
if (ret)
return ret;
ret = get_emul(dev, &emul, &ops);
if (ret)
return ret;
if (priv->test_mode) {
/*
* For testing, don't allow writing above 100KHz for writes and
* 400KHz for reads.
*/
is_read = nmsgs > 1;
if (i2c->speed_hz > (is_read ? 400000 : 100000)) {
debug("%s: Max speed exceeded\n", __func__);
return -EINVAL;
}
}
return ops->xfer(emul, msg, nmsgs);
}
static const struct dm_i2c_ops sandbox_i2c_ops = {
.xfer = sandbox_i2c_xfer,
};
static const struct udevice_id sandbox_i2c_ids[] = {
{ .compatible = "sandbox,i2c" },
{ }
};
U_BOOT_DRIVER(i2c_sandbox) = {
.name = "i2c_sandbox",
.id = UCLASS_I2C,
.of_match = sandbox_i2c_ids,
.ops = &sandbox_i2c_ops,
.priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv),
};