Djam/u-boot
1
0
Fork 0
mirror of https://github.com/u-boot/u-boot.git synced 2025-05-08 10:39:08 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

dm: sandbox: i2c: Add a new 'emulation parent' uclass

Browse source 
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 <sjg@chromium.org>
This commit is contained in:
Simon Glass 2018-11-18 08:14:33 -07:00
parent 25cbb47090
commit b7c25b11b6
3 changed files with 99 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

21
include/i2c.h
View file

@ -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
/*