From b7c25b11b6a1e3f840464224309b72a91b65bc56 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Sun, 18 Nov 2018 08:14:33 -0700 Subject: dm: sandbox: i2c: Add a new 'emulation parent' uclass Sandbox i2c works using emulation drivers which are currently children of the i2c device: rtc_0: rtc@43 { reg = <0x43>; compatible = "sandbox-rtc"; emul { compatible = "sandbox,i2c-rtc"; }; }; In this case the emulation device is attached to i2c bus on address 0x43 and provides the Real-Time-Clock (RTC) functionality. However this is not ideal, since every device on an I2C bus has a child device. This is only really the case for sandbox, but we want to avoid special-case code for sandbox. A better approach seems to be to add a separate node on the bus, an 'emulation parent'. This can be given a bogus address (such as 0xff) and hides all the emulators away. Then we can use a phandle to point from the device to the correct emualtor, and only on sandbox. The code to find an emulator does not interfere with normal i2c operation. Add a new UCLASS_I2C_EMUL_PARENT uclass which allows finding an emulator given a bus, and finding a bus given an emulator. This will be used in a follow-on patch. Signed-off-by: Simon Glass --- include/i2c.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'include/i2c.h') diff --git a/include/i2c.h b/include/i2c.h index d33f827500b..ccffc195527 100644 --- a/include/i2c.h +++ b/include/i2c.h @@ -536,6 +536,27 @@ int i2c_chip_ofdata_to_platdata(struct udevice *dev, struct dm_i2c_chip *chip); */ void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs); +/** + * i2c_emul_find() - Find an emulator for an i2c sandbox device + * + * This looks at the device's 'emul' phandle + * + * @dev: Device to find an emulator for + * @emulp: Returns the associated emulator, if found * + * @return 0 if OK, -ENOENT or -ENODEV if not found + */ +int i2c_emul_find(struct udevice *dev, struct udevice **emulp); + +/** + * i2c_emul_get_device() - Find the device being emulated + * + * Given an emulator this returns the associated device + * + * @emul: Emulator for the device + * @return device that @emul is emulating + */ +struct udevice *i2c_emul_get_device(struct udevice *emul); + #ifndef CONFIG_DM_I2C /* -- cgit v1.2.3