Like stm32 L4 does,
when the STM32WBx SoC goes into STOP mode, the SPI device is disabled.
This cause the pins to not be drived anymore (i.e. they are floating)
except through their pull-up or pull-down.
From the logical point of view, the NSS pin is held high by a pull-up
so it's not a problem if the other pins are floating. However those pins
are floating input for the slaves, which increase their power
consumption.
The solution is to hold the state of the pins through a pull-up or a
pull-down. This is already done for the NSS and MOSI pins, but not for
SCK. Fix that by using pull-down on the SCK pin the same way it is
already done for the MOSI pin.
Signed-off-by: Francois Ramu <francois.ramu@st.com>
* Define USB driver for base stm32wb device.
* Enable USB for the nucleo_wb55rg board.
* Properly initialize USB power + clock for the platform.
Signed-off-by: Pete Johanson <peter@peterjohanson.com>
To work efficiently, SPI_NSS pins require pull-up configuration.
Fix this for whole STM32 series.
Fixes#17998
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
Fixes#16739. Changed the STM32's SPI MISO/MOSI configurations in order
to reduce the power consumption by approximately 20uA per pin.
According to STM32's Application Notes on GPIO configuration for
low-power consumption, the input pins should be configured with internal
pull-up or pull-down resistor. If a pin is configured as a floating
input, and there is no signal present, the Schmitt trigger randomly
toggles between the logical levels induced by the external noise, thus
increasing the consumption.
Signed-off-by: Ioannis Konstantelias <ikonstadel@gmail.com>
