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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2014 Google, Inc
*/
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <log.h>
#include <dm/device-internal.h>
#include <dm/uclass-internal.h>
/*
* i2c emulation works using an 'emul' node at the bus level. Each device in
* that node is in the UCLASS_I2C_EMUL uclass, and emulates one i2c device. A
* pointer to the device it emulates is in the 'dev' property of the emul device
* uclass platdata (struct i2c_emul_platdata), put there by i2c_emul_find().
* When sandbox wants an emulator for a device, it calls i2c_emul_find() which
* searches for the emulator with the correct address. To find the device for an
* emulator, call i2c_emul_get_device().
*
* The 'emul' node is in the UCLASS_I2C_EMUL_PARENT uclass. We use a separate
* uclass so avoid having strange devices on the I2C bus.
*/
/**
* struct i2c_emul_uc_platdata - information about the emulator for this device
*
* This is used by devices in UCLASS_I2C_EMUL to record information about the
* device being emulated. It is accessible with dev_get_uclass_platdata()
*
* @dev: Device being emulated
*/
struct i2c_emul_uc_platdata {
struct udevice *dev;
};
struct udevice *i2c_emul_get_device(struct udevice *emul)
{
struct i2c_emul_uc_platdata *uc_plat = dev_get_uclass_platdata(emul);
return uc_plat->dev;
}
int i2c_emul_find(struct udevice *dev, struct udevice **emulp)
{
struct i2c_emul_uc_platdata *uc_plat;
struct udevice *emul;
int ret;
ret = uclass_find_device_by_phandle(UCLASS_I2C_EMUL, dev,
"sandbox,emul", &emul);
if (ret) {
log_err("No emulators for device '%s'\n", dev->name);
return ret;
}
uc_plat = dev_get_uclass_platdata(emul);
uc_plat->dev = dev;
*emulp = emul;
return device_probe(emul);
}
UCLASS_DRIVER(i2c_emul) = {
.id = UCLASS_I2C_EMUL,
.name = "i2c_emul",
.per_device_platdata_auto_alloc_size =
sizeof(struct i2c_emul_uc_platdata),
};
/*
* This uclass is a child of the i2c bus. Its platdata is not defined here so
* is defined by its parent, UCLASS_I2C, which uses struct dm_i2c_chip. See
* per_child_platdata_auto_alloc_size in UCLASS_DRIVER(i2c).
*/
UCLASS_DRIVER(i2c_emul_parent) = {
.id = UCLASS_I2C_EMUL_PARENT,
.name = "i2c_emul_parent",
.post_bind = dm_scan_fdt_dev,
};
static const struct udevice_id i2c_emul_parent_ids[] = {
{ .compatible = "sandbox,i2c-emul-parent" },
{ }
};
U_BOOT_DRIVER(i2c_emul_parent_drv) = {
.name = "i2c_emul_parent_drv",
.id = UCLASS_I2C_EMUL_PARENT,
.of_match = i2c_emul_parent_ids,
};
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