usb: typec: fsa4480: Check if the chip is really there

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Currently, the driver will happily register the switch/mux devices, and
so long as the i2c master doesn't complain, the user would never know
there's something wrong.

Add a device id check (based on [1]) and return -ENODEV if the read
fails or returns nonsense.

Checking the value on a Qualcomm SM6115P-based Lenovo Tab P11 tablet,
the ID mentioned in the datasheet does indeed show up:
 fsa4480 1-0042: Found FSA4480 v1.1 (Vendor ID = 0)

[1] https://www.onsemi.com/pdf/datasheet/fsa4480-d.pdf

Fixes: 1dc246320c ("usb: typec: mux: Add On Semi fsa4480 driver")
Cc: stable <stable@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240729-topic-fs4480_check-v3-1-f5bf732d3424@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Konrad Dybcio 2024-07-29 10:42:58 +02:00 • committed by Greg Kroah-Hartman

parent 973a578916

commit e885f5f1f2

1 changed files with 14 additions and 0 deletions

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drivers/usb/typec/mux/fsa4480.c

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