Add some details to help new users learn how to manage the nodes
for compatibles corresponding to IP blocks on Nordic SoCs.
The focus is on IP blocks where the pinmux is configured in
devicetree. These typically have individual properties for each pin,
like a SCK pin on a SPI peripheral, which correspond directly to a
PSEL register value. These violate the usual devicetree convention of
using a 'foo-gpios <&gpioX ...>' phandle property and work in ways
that only make sense if you understand the underlying register map, so
it's worth explaining them a bit more carefully.
Skip these two bindings, which have no drivers: nordic,nrf-i2s.yaml,
nordic,nrf-pdm.yaml.
Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
This commit introduces separate "compatible" strings for dts nodes
representing different types of Nordic TWI peripherals. Previously
"nordic,nrf-i2c" was used for both TWI and TWIM, and TWIS was not
supported.
Quite a few files need to be touched by this commit but the changes can
be divided into groups of related or very similar ones, distinguishable
by the initial part of the path to the modified file:
* dts/bindings/i2c/
new bindings for "nordic,nrf-twim" and "nordic,nrf-twis" are added
and the one for "nordic,nrf-i2s" is renamed to "nordic,nrf-twi",
common fields for all these bindings are extracted to a shared file
* dts/arm/nordic/
"compatible" properties in i2cX nodes are updated (when there is no
choice as only one type of TWI peripheral is available) or replaced
with a comment pointing out that the proper type of peripheral needs
to be picked at some upper layer
* drivers/i2c/
both flavors of i2c_nrfx drivers are updated with the new names of
macros generated from dts
* boards/
all i2cX nodes in dts files for boards equipped with an nRF chip are
updated with the proper "compatible" property, according to the type
of TWI peripheral that is currently selected for the board by the
corresponding Kconfig choice option (I2C_x_NRF_TWI*)
Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
Martí Bolívar