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| author | Donggeun Yoo <donggeunyoo.kernel@gmail.com> | 2026-09-02 00:21:26 +0900 |
|---|---|---|
| committer | Jonathan Cameron <jonathan.cameron@oss.qualcomm.com> | 2026-09-07 02:24:53 +0100 |
| commit | e24328974a88aa8541e94e8bb8dfa2ade1b3c45d (patch) | |
| tree | 43a2533acc955d11f5cb8be1ecba0ab8ba4cbb1e /Documentation/i2c/slave-eeprom-backend.rst | |
| download | linux-stable-e24328974a88aa8541e94e8bb8dfa2ade1b3c45d.tar.gz linux-stable-e24328974a88aa8541e94e8bb8dfa2ade1b3c45d.zip | |
iio: proximity: vl53l0x-i2c: claim direct mode for raw readsgrafted
vl53l0x_read_raw() starts a single-shot ranging measurement and reads
back the result. Once the triggered buffer is enabled the sensor runs in
continuous mode and its data-ready interrupt is routed to the trigger,
so a concurrent in_distance_raw read disturbs the streaming setup and
never gets its completion, returning -ETIMEDOUT.
The original submission claimed direct mode here, but it was dropped
during review because the driver had no buffer support at the time [1].
Continuous (buffered) mode was later added without restoring the
claim [2], reintroducing the conflict.
Reject direct reads while buffered capture is active by claiming direct
mode around the measurement, as the vl53l1x sibling already does.
Fixes: 762186c6e7b1 ("iio: proximity: vl53l0x-i2c: Added continuous mode support")
Link: https://lore.kernel.org/linux-iio/20180911160300.GA9212@himanshu-Vostro-3559/ [1]
Link: https://lore.kernel.org/linux-iio/20240909101508.263085-3-abhashkumarjha123@gmail.com/ [2]
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Diffstat (limited to 'Documentation/i2c/slave-eeprom-backend.rst')
| -rw-r--r-- | Documentation/i2c/slave-eeprom-backend.rst | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/i2c/slave-eeprom-backend.rst b/Documentation/i2c/slave-eeprom-backend.rst new file mode 100644 index 000000000..38d951f10 --- /dev/null +++ b/Documentation/i2c/slave-eeprom-backend.rst @@ -0,0 +1,26 @@ +============================== +Linux I2C slave EEPROM backend +============================== + +by Wolfram Sang <wsa@sang-engineering.com> in 2014-20 + +This backend simulates an EEPROM on the connected I2C bus. Its memory contents +can be accessed from userspace via this file located in sysfs:: + + /sys/bus/i2c/devices/<device-directory>/slave-eeprom + +The following types are available: 24c02, 24c32, 24c64, and 24c512. Read-only +variants are also supported. The name needed for instantiating has the form +'slave-<type>[ro]'. Examples follow: + +24c02, read/write, address 0x64: + # echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-1/new_device + +24c512, read-only, address 0x42: + # echo slave-24c512ro 0x1042 > /sys/bus/i2c/devices/i2c-1/new_device + +You can also preload data during boot if a device-property named +'firmware-name' contains a valid filename (DT or ACPI only). + +As of 2015, Linux doesn't support poll on binary sysfs files, so there is no +notification when another master changed the content. |