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