Messages in this thread | | | Date | Fri, 13 May 2022 20:59:29 +0300 | Subject | Re: [PATCH v4 3/3] iio: light: Add support for ltrf216a sensor | From | Dmitry Osipenko <> |
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13.05.2022 16:40, Shreeya Patel пишет: > Also, why would we want to do a SW reset here? > > In the datasheet, I could see the following steps to enable the sensor > Supply VDD to Sensor (Sensor in Standby Mode) ---> Wait 100 ms (min) - > initial startup time > ---> I2C Command (Write) To enable sensor to Active Mode
For example, if you'll do kexec from other kernel, say downstream kernel, then the h/w state is undetermined for us. It's a common problem with downstream drivers that they rely on a specific state left from bootloader, which is often unacceptable for upstream.
If we'll do the SW reset on probe, then we'll bring h/w into the predictable state and won't depend on state left from bootloader or anything else that touched h/w before us.
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