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| author | Matt DeVillier <matt.devillier@gmail.com> | 2022-05-19 19:03:07 -0500 |
|---|---|---|
| committer | Paul Fagerburg <pfagerburg@chromium.org> | 2022-05-31 13:43:39 +0000 |
| commit | ee849ba62574ac52e04d80f774a374d9b7558f67 (patch) | |
| tree | 98d83a6f66f113c4717cff4006a620dc7d3b5727 /src/include | |
| parent | 57097130d5e4880e39ce8f63eba6f11d7c51e94c (diff) | |
| download | coreboot-ee849ba62574ac52e04d80f774a374d9b7558f67.tar.gz coreboot-ee849ba62574ac52e04d80f774a374d9b7558f67.tar.bz2 coreboot-ee849ba62574ac52e04d80f774a374d9b7558f67.zip | |
dev/i2c_bus: Add declaration, implementation of i2c_dev_detect()
This patch adds the I2C equivalent of an SMBus quick write to an I2C
device, which is used by some I2C drivers as a way to probe the
existence (or absence) of a certain device on the bus, based on
whether or not a 0-byte write to an I2C address is ACKed or NACKed.
i2c_dev_detect() is implemented using the existing i2c bus ops transfer()
function, so no further work is needed for existing controller drivers
to utilize this functionality.
Change-Id: I9b22bdc0343c846b235339f85d9f70b20f0f2bdd
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64537
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@tutanota.com>
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/device/i2c_bus.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/include/device/i2c_bus.h b/src/include/device/i2c_bus.h index 42f461dc9e3a..1a7e777278c6 100644 --- a/src/include/device/i2c_bus.h +++ b/src/include/device/i2c_bus.h @@ -13,6 +13,11 @@ struct i2c_bus_operations { int (*transfer)(struct device *, const struct i2c_msg *, size_t count); }; +/** + * Determine device presence at a given slave address. + */ +bool i2c_dev_detect(struct device *dev, unsigned int addr); + /* * Returns the first upstream facing link whose bus implements either * `i2c_bus_operations` *or* `smbus_bus_operations`. |