pinctrl: stm32: parse pinctrl nodes without subnodes as well ...

The bindings allow the pinmux node to occur directly in the node under
the pin controller as well. Check for this and support both types of
pinctrl specification.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

pinctrl: demote dev_info on successful probes to dev_dbg ...

The SoC's pin controller is virtually always built and probed, so
there's is little information to gain from the fact it was successfully
probed. Have the success message show up as debug message to reduce probe
clutter like this:

	NOTICE: stm32-pinctrl soc:pin-controller@50002000.of: pinctrl/gpio driver registered
	NOTICE: stm32-pinctrl soc:pin-controller-z@54004000.of: pinctrl/gpio driver registered

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

pinctrl: stm32: fix debug print of uninitialized variable ...

mode and alt are printed with the dev_dbg before they are initialized.
Remedy this by moving the dev_dbg after them.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

pinctrl: stm32: fix error path when gpio chip is not found ...

Current error path has two issues:

- PTR_ERR is applied to a NULL pointer, so even error conditions return
  zero, which is a valid successful return.
- The return value is stored into an unsigned integer which is checked
  to be less than zero, so the error is never handled.

Fix both issues.

Fixes: f4f933a64 ("pinctrl: add driver for STM32 GPIO and pin multiplexer")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

pinctrl: stm32: add debug output in set_state callback ...

There's already a debug output whenever a pin is configured, extend this
by printing a "header" with the node name and how many pins configurations
will follow.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

pinctrl: add driver for STM32 GPIO and pin multiplexer ...

This adds driver support for the 12 GPIO banks on the STM32MP157.
As they are accessible to both the Cortex-A cores as well as the Cortex-M
core, modifications to these are protected by a hardware spinlock
and clocks are enabled/disabled as required.

All register fiddling done by the driver is collected in <soc/stm32/gpio.h>,
so future PBL code may make use of it as well to chainload barebox proper.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>