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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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