Messages in this thread | | | Date | Thu, 12 May 2022 14:11:06 -0500 | Subject | Re: [PATCH v2 0/2] iio: humidity: si7020: Check device property for skipping reset in probe | From | Eddie James <> |
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On 5/12/22 11:48, Jonathan Cameron wrote: > On Thu, 12 May 2022 11:20:18 -0500 > Eddie James <eajames@linux.ibm.com> wrote: > >> I2C commands issued after the SI7020 is starting up or after reset >> can potentially upset the startup sequence. Therefore, the host >> needs to wait for the startup sequence to finish before issuing >> further i2c commands. This is impractical in cases where the SI7020 >> is on a shared bus or behind a mux, which may switch channels at >> any time (generating I2C traffic). Therefore, check for a device >> property that indicates that the driver should skip resetting the >> device when probing. > Why not lock the bus? It's not ideal, but then not resetting and hence > potentially ending up in an unknown state isn't great either.
Also, I should mention that in our case we can rely on the power on reset, so the device should be in a known state.
Eddie
> > Jonathan > >> Changes since v1: >> - Fix dt binding document >> >> Eddie James (2): >> dt-bindings: iio: humidity: Add si7020 bindings >> iio: humidity: si7020: Check device property for skipping reset in probe >> >> .../bindings/iio/humidity/silabs,si7020.yaml | 47 +++++++++++++++++++ >> .../devicetree/bindings/trivial-devices.yaml | 2 - >> drivers/iio/humidity/si7020.c | 14 +++--- >> 3 files changed, 55 insertions(+), 8 deletions(-) >> create mode 100644 Documentation/devicetree/bindings/iio/humidity/silabs,si7020.yaml >>
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