pinctrl: sunxi: Add driver for Allwinner D1

This SoC contains a pinctrl with a new register layout. Use the variant
parameter to set the right register offsets. This pinctrl also increases
the number of functions per pin from 8 to 16, taking advantage of all 4
bits in the mux config field (so far, only functions 0-8 and 14-15 are
used). This increases the maximum possible number of functions.

Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20220713025233.27248-7-samuel@sholland.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Make some layout parameters dynamic

Starting with the D1/D1s/T113 SoC, Allwinner changed the layout of the
pinctrl registers. This new layout widens the drive level field, which
affects the pull register offset and the overall bank size.

In order to support multiple register layouts, some of the layout
parameters need to be set based on the pinctrl variant. This requires
passing the pinctrl struct pointer to the register/offset calculation
functions.

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220713025233.27248-6-samuel@sholland.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Refactor register/offset calculation

Starting with the D1/D1s/T113 SoC, Allwinner changed the layout of the
pinctrl registers. This new layout widens the drive level field, which
affects the pull register offset and the overall bank size.

As a first step to support this, combine the register and offset
calculation functions, and refactor the math to depend on one constant
for field widths instead of three. This minimizes the code size impact
of making some of the factors dynamic.

While rewriting these functions, move them to the implementation file,
since that is the only file where they are used. And make the comment
more generic, without mentioning specific offsets/sizes.

The callers are updated to expect a shifted mask, and to use consistent
terminology (reg/shift/mask/val).

Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220713025233.27248-5-samuel@sholland.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Support the 2.5V I/O bias mode

H616 and newer SoCs feature a 2.5V I/O bias mode in addition to the
1.8V and 3.3V modes. This mode is entered by selecting the 3.3V level
and disabling the "withstand function".

H616 supports this capability on its main PIO only. A100 supports this
capability on both its PIO and R-PIO.

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220713025233.27248-4-samuel@sholland.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: v3s: introduce support for V3

Introduce the GPIO pins that is only available on V3 (not on V3s) to the
V3s pinctrl driver.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>

Link: https://lore.kernel.org/r/20190728031227.49140-2-icenowy@aosc.io
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Support I/O bias voltage setting on H6

H6 SoC has a "pio group withstand voltage mode" register (datasheet
description), that needs to be used to select either 1.8V or 3.3V I/O mode,
based on what voltage is powering the respective pin banks and is thus used
for I/O signals.

Add support for configuring this register according to the voltage of the
pin bank regulator (if enabled).

This is similar to the support for I/O bias voltage setting patch for A80
and the same concerns apply. See:

commit 402bfb3c1352 ("Support I/O bias voltage setting on A80")

Signed-off-by: Ondrej Jirman <megous@megous.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Prepare for alternative bias voltage setting methods

H6 has a different I/O voltage bias setting method than A80. Prepare
existing code for using alternative bias voltage setting methods.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Support I/O bias voltage setting on A80

The A80 SoC has configuration registers for I/O bias voltage. Incorrect
settings would make the affected peripherals inoperable in some cases,
such as Ethernet RGMII signals biased at 2.5V with the settings still
at 3.3V. However low speed signals such as MDIO on the same group of
pins seem to be unaffected.

Previously there was no way to know what the actual voltage used was,
short of hard-coding a value in the device tree. With the new pin bank
regulator supply support in place, the driver can now query the
regulator for its voltage, and if it's valid (as opposed to being the
dummy regulator), set the bias voltage setting accordingly.

Add a quirk to denote the presence of the configuration registers, and
a function to set the correct setting based on the voltage read back
from the regulator.

This is only done when the regulator is first acquired and enabled.
While it would be nice to have a notifier on the regulator so that when
the voltage changes, the driver can update the setting, in practice no
board currently supports dynamic changing of the I/O voltages.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Consider pin_base when calculating regulator array index

On most newer Allwinner SoCs, there are two pinctrl devices, the PIO and
R_PIO. PIO covers pin-banks PA to PI (PJ and PK have not been seen),
while R_PIO covers PL to PN. The regulator array only has space for 12
entries, which was designed to cover PA to PL. On the A80, the pin banks
go up to PN, which would be the 14th entry in the regulator array.
However since the driver only needs to track regulators for its own pin
banks, the array only needs to have 9 entries, and also take in to
account the value of pin_base, such that the regulator for the first
pin-bank of the pinctrl device, be it "PA" or "PL" uses the first entry
of the array.

Base the regulator array index on pin_base, such that "PA" for PIO and
"PL" for R_PIO both take the first element within their respective
device's regulator array.

Also decrease the size of the regulator array to 9, just enough to cover
"PA" to "PI".

Fixes: 9a2a566adb00 ("pinctrl: sunxi: Deal with per-bank regulators")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Deal with per-bank regulators

The Allwinner SoCs have on most of their GPIO banks a regulator input.

This issue was mainly ignored so far because either the regulator was a
static regulator that would be providing power anyway, or the bank was used
for a feature unsupported so far (CSI). For the odd cases, enabling it in
the bootloader was the preferred option.

However, now that we are starting to support those features, and that we
can't really rely on the bootloader for this, we need to model those
regulators as such in the DT.

This is slightly more complicated than what it looks like, since some
regulators will be tied to the PMIC, and in order to have access to the
PMIC bus, you need to mux its pins, which will need the pinctrl driver,
that needs the regulator driver to be registered. And this is how you get a
circular dependency.

In practice however, the hardware cannot fall into this case since it would
result in a completely unusable bus. In order to avoid that circular
dependency, we can thus get and enable the regulators at pin_request time.
We'll then need to account for the references of all the pins of a
particular branch to know when to put the reference, but it works pretty
nicely once implemented.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: change irq_bank_base to irq_bank_map

The Allwinner H6 SoC have its pin controllers with the first IRQ-capable
GPIO bank at IRQ bank 1 and the second bank at IRQ bank 5.

Change the current code that uses IRQ bank base to a IRQ bank map, in
order to support the case that holes exist among IRQ banks.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: introduce IRQ bank conversion function

The Allwinner H6 SoC have its pin controllers with the first IRQ-capable
GPIO bank at IRQ bank 1 and the second bank at IRQ bank 5. Some
refactors in the sunxi pinctrl framework are needed.

This commit introduces a IRQ bank conversion function, which replaces
the "(bank_base + bank)" code in IRQ register access.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: refactor irq related register function to have desc

As the new H6 SoC has holes in the IRQ registers, refactor the IRQ
related register function for getting the full pinctrl desc structure.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Introduce the strict flag

Our pinctrl device should have had strict set all along. However, it wasn't
the case, and most of our old device trees also have a pinctrl group in
addition to the GPIOs properties, which mean that we can't really turn it
on now.

All our new SoCs don't have that group, so we should still enable that mode
on the newer one though.

In order to enable it by default, add a flag that will allow to disable
that mode that should be set by pinctrl drivers that cannot be migrated.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Add SoC ID definitions for A10, A20 and R40 SoCs

Allwinner A10, A20 and R40 SoCs have similar GPIO layout.

Add SoC definitions in pinctrl-sunxi.h, in order to merge A20 support
into A10 driver, and add R40 support into it.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: make use of raw_spinlock variants

The sunxi pinctrl driver currently implement an irq_chip for handling
interrupts; due to how irq_chip handling is done, it's necessary for the
irq_chip methods to be invoked from hardirq context, even on a a
real-time kernel. Because the spinlock_t type becomes a "sleeping"
spinlock w/ RT kernels, it is not suitable to be used with irq_chips.

A quick audit of the operations under the lock reveal that they do only
minimal, bounded work, and are therefore safe to do under a raw spinlock.

Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Support A31/A31s with pinctrl variants

The A31s is a trimmed down version of the A31. Some hardware blocks
are removed, thus not available for muxing on the external pins.
Some external pins were directly removed.

This makes it easy to support the A31s pin controller with the A31
driver. We just mark the pins and functions that were trimmed as
A31 only.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Add common sun5i pinctrl driver

The sun5i SoCs (A10s, A13, GR8) are all based on the same die fit in
different packages. Hence, the pins and functions available are just the
based on the same set, each SoC having a different subset.

Introduce a common pinctrl driver that supports multiple variants to allow
to put as much as we can in common.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Add pinctrl variants

Some SoCs are either supposed to be pin compatible (A10 and A20 for
example), or are just repackaged versions of the same die (A10s, A13, GR8).

In those case, having a full blown pinctrl driver just introduces
duplication in both data size and maintainance effort.

Add a variant option to both pins and functions to be able to limit the
pins and functions described only to a subset of the SoC we support with a
given driver.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Add support for interrupt debouncing

The pin controller found in the Allwinner SoCs has support for interrupts
debouncing.

However, this is not done per-pin, preventing us from using the generic
pinconf binding for that, but per irq bank, which, depending on the SoC,
ranges from one to five.

Introduce a device-wide property to deal with this using a microsecond
resolution. We can re-use the per-pin input-debounce property for that, so
let's do it!

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Add support for fetching pinconf settings from hardware

The sunxi pinctrl driver only caches whatever pinconf setting was last
set on a given pingroup. This is not particularly helpful, nor is it
correct.

Fix this by actually reading the hardware registers and returning
the correct results or error codes. Also filter out unsupported
pinconf settings. Since this driver has a peculiar setup of 1 pin
per group, we can support both pin and pingroup pinconf setting
read back with the same code. The sunxi_pconf_reg helper and code
structure is inspired by pinctrl-msm.

With this done we can also claim to support generic pinconf, by
setting .is_generic = true in pinconf_ops.

Also remove the cached config value. The behavior of this was never
correct, as it only cached 1 setting instead of all of them. Since
we can now read back settings directly from the hardware, it is no
longer required.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Fix A33 external interrupts not working

pinctrl-sun8i-a33.c (and the dts) declare only 2 interrupt banks,
where as the closely related a23 has 3 banks. This matches with the
datasheet for the A33 where only interrupt banks B and G are specified
where as the A23 has banks A, B and G.

However the A33 being the A23 derative it is means that the interrupt
configure/status io-addresses for the 2 banks it has are not changed
from the A23, iow they have the same address as if bank A was still
present. Where as the sunxi pinctrl currently tries to use the A23 bank
A addresses for bank B, since the pinctrl code does not know about the
removed bank A.

Add a irq_bank_base parameter and use this where appropriate to take
the missing bank A into account.

This fixes external interrupts not working on the A33 (tested with
an i2c touchscreen controller which uses an external interrupt).

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sun4i: GPIOs configured as irq must be set to input before reading

On sun4i-a10, when GPIOs are configured as external interrupt the value for
them in the data register does not seem to get updated, so set their mux to
input (and restore afterwards) when reading the pin.

Missed edges seem to be buffered, so this does not introduce a race
condition.

I've also tested this on sun5i-a13 and sun7i-a20 and those do not seem to
be affected, the input value representation in the data register does seem
to correctly get updated to the actual pin value while in irq mode there.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Add PN bank base pin

The A80 R-PIO controller has one more bank that what we've seen so far, add the
PN pin bank.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Implement multiple interrupt banks support

The A23 and A31 support multiple interrupt banks. Support it by adding a linear
domain covering all the banks. It's trickier than it should because there's an
interrupt per bank, so we have multiple interrupts using the same domain.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Declare the number of interrupt banks in the descriptor

Declare in the description structure associated to the compatible the number of
interrupt banks the device has. For now, we're not doing anything with it.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Add macro definition for pinctrl with more than one interrupt

The A31 and A23, unlike the other Allwinner SoCs, have several interrupts banks
and parent interrupts, while the other only have up to 32 interrupts in a
single bank and a single parent interrupt.

Start supporting it by introducing a function macro to declare irq functions
and their banks.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: sunxi: Libraryse the driver

This will allow to have multiple drivers using the same core code, and
eventually, retire pinctrl-sunxi-pins.h

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

pinctrl: sunxi: Replace hardcoded pin defines by a macro

We previously had an evergrowing (and exhaustive) list of the pins that could
be used on any Allwinner SoCs. These defines were then used by each pinctrl
driver to declare the list of functions for this pin. Since it's pretty much
all boilerplate, we can remove it just by a single macro.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

pinctrl: sunxi: Move the Allwinner pinctrl driver to its own directory

This will allow to create numerous files without crippling the main pinctrl
directory.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>