pinctrl: keembay: Convert to use grp member

Convert drivers to use grp member embedded in struct group_desc,
because other members will be removed to avoid duplication and
desynchronisation of the generic pin group description.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231211190321.307330-10-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: keembay: Convert to use struct pingroup

The pin control header provides struct pingroup.
Utilize it instead of open coded variants in the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231204160033.1872569-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: keembay: rework loops looking for groups names

Make the outer loop iterate over functions as that's the real subject.
This simplifies code (and reduces amount of lines of code) as allocating
memory for names doesn't require extra checks anymore.

While at it use local "group_names" variable. The plan for
"struct function_desc" is to make its "group_names" /double/ const. That
will allow drivers to use it with static const data.

This keembay "group_names" change is required to avoid:
drivers/pinctrl/pinctrl-keembay.c: In function 'keembay_add_functions':
drivers/pinctrl/pinctrl-keembay.c:1594:8: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
1594 | grp = func->group_names;
| ^

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20211216162206.8027-3-zajec5@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: keembay: comment process of building functions a bit

This should make code a bit easier to follow. While at it use some "for"
loops to simplify array iteration loops.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20211216162206.8027-2-zajec5@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: Add Intel Keem Bay pinctrl driver

About Intel Keem Bay:
-------------------
Intel Keem Bay is a computer vision AI accelerator SoC based on ARM CPU.
Documentation of Keem Bay: Documentation/vpu/vpu-stack-overview.rst.

Pinctrl IP:
----------
The SoC has a customised pinmux controller IP which controls pin
multiplexing and configuration.

Keem Bay pinctrl IP is not based on and have nothing in common with the
existing pinctrl drivers. The registers used are incompatible with the
existing drivers, so it requires a new driver.

Add pinctrl driver to enable pin control support in the Intel Keem Bay SoC.

Co-developed-by: Vineetha G. Jaya Kumaran <vineetha.g.jaya.kumaran@intel.com>
Signed-off-by: Vineetha G. Jaya Kumaran <vineetha.g.jaya.kumaran@intel.com>
Co-developed-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
Signed-off-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
Reviewed-by: Mark Gross <mgross@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210806142527.29113-3-lakshmi.sowjanya.d@intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>