pinctrl: apple-gpio: Add missing header(s)

Do not imply that some of the generic headers may be always included.
Instead, include explicitly what we are direct user of.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

pinctrl: apple: Use a raw spinlock for the regmap

The irqchip ops are called with a raw spinlock held, so the subsequent
regmap usage cannot use a plain spinlock.

spi-hid-apple-of spi0.0: spihid_apple_of_probe:74

=============================
[ BUG: Invalid wait context ]
5.18.0-asahi-00176-g0fa3ab03bdea #1337 Not tainted
-----------------------------
kworker/u20:3/86 is trying to lock:
ffff8000166b5018 (pinctrl_apple_gpio:462:(&regmap_config)->lock){....}-{3:3}, at: regmap_lock_spinlock+0x18/0x30
other info that might help us debug this:
context-{5:5}
7 locks held by kworker/u20:3/86:
#0: ffff800017725d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1c8/0x670
#1: ffff80001e33bdd0 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1c8/0x670
#2: ffff800017d629a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x30/0x17c
#3: ffff80002414e618 (&ctlr->add_lock){+.+.}-{4:4}, at: spi_add_device+0x40/0x80
#4: ffff800024116990 (&dev->mutex){....}-{4:4}, at: __device_attach+0x30/0x17c
#5: ffff800022d4be58 (request_class){+.+.}-{4:4}, at: __setup_irq+0xa8/0x720
#6: ffff800022d4bcc8 (lock_class){....}-{2:2}, at: __setup_irq+0xcc/0x720

Fixes: a0f160ffcb83 ("pinctrl: add pinctrl/GPIO driver for Apple SoCs")
Signed-off-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20220524142206.18833-1-marcan@marcan.st
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: Make it work as a module

We need MODULE_DEVICE_TABLE for module autoloading to work.

Signed-off-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20220502092335.30670-1-marcan@marcan.st
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple-gpio: Make the irqchip immutable

Prevent gpiolib from messing with the irqchip by advertising
the irq_chip structure as immutable, making it const, and adding
the various calls that gpiolib relies upon.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419141846.598305-7-maz@kernel.org

pinctrl: apple-gpio: fix flexible_array.cocci warnings

Zero-length and one-element arrays are deprecated, see
Documentation/process/deprecated.rst
Flexible-array members should be used instead.

Generated by: scripts/coccinelle/misc/flexible_array.cocci

CC: Joey Gouly <joey.gouly@arm.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2111271859250.2864@hadrien
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: return an error if pinmux is missing in the DT

If of_property_count_u32_elems returned 0, return -EINVAL to indicate
a failure. Previously this would return 0.

Fixes: a0f160ffcb83 ("pinctrl: add pinctrl/GPIO driver for Apple SoCs")
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-12-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: use modulo rather than bitwise and

This expresses the intention clearer.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-11-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: don't set gpio_chip.of_node

The gpio core code sets of_node, so no need to do it here.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-10-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: remove gpio-controller check

Having this missing, but everything else valid shouldn't result
in a failure.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-9-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: give error label a specific name

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-8-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: make apple_gpio_get_direction more readable

Try to make this more readable by not using a long line with
a ternary operator.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-7-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: handle regmap_read errors

Explicitly return 0 if the regmap_read fails.
Also change a uint32_t to a u32.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-6-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: add missing bits.h header

This is needed for the BIT(n) macro.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-5-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: use C style comment

This is the preferred comment style.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-4-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: add missing comma

Add a missing comma at the end of the regmap initialisation.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-3-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: fix some formatting issues

Reflow some of the code now that the extra '_gpio' was removed.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-2-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: apple: Always return valid type in apple_gpio_irq_type

apple_gpio_irq_type can possibly return -EINVAL which triggers the
following compile error with gcc 9 because the type no longer fits
into the mask.

drivers/pinctrl/pinctrl-apple-gpio.c: In function 'apple_gpio_irq_set_type':
././include/linux/compiler_types.h:335:38: error: call to '__compiletime_assert_289' declared with attribute error: FIELD_PREP: value too large for the field
335 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^
[...]
drivers/pinctrl/pinctrl-apple-gpio.c:294:7: note: in expansion of macro 'FIELD_PREP'
294 | FIELD_PREP(REG_GPIOx_MODE, irqtype));
| ^~~~~~~~~~

Fix this by making the return value always valid and instead checking
for REG_GPIOx_IN_IRQ_OFF in apple_gpio_irq_set_type and return -EINVAL
from there.

Fixes: a0f160ffcb83 ("pinctrl: add pinctrl/GPIO driver for Apple SoCs")
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20211101150640.46553-1-sven@svenpeter.dev
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: add pinctrl/GPIO driver for Apple SoCs

This driver adds support for the pinctrl / GPIO hardware found
on some Apple SoCs.

Co-developed-by: Stan Skowronek <stan@corellium.com>
Signed-off-by: Stan Skowronek <stan@corellium.com>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Acked-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211026175815.52703-5-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>