ARM: shmobile: rcar-gen2: Increase refcount for new reference

In rcar_gen2_regulator_quirk(), for_each_matching_node_and_match() will
automatically increase and decrease the refcount. However, we should
call of_node_get() for the new reference created in 'quirk->np'.
Besides, we also should call of_node_put() before the 'quirk' being
freed.

Signed-off-by: Liang He <windhl@126.com>
Link: https://lore.kernel.org/r/20220701121804.234223-1-windhl@126.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

ARM: shmobile: rcar-gen2: Drop comma after OF match table sentinel

It does not make sense to have a comma after a sentinel, as any new
elements must be added before the sentinel.

Add a comment to clarify the purpose of the empty element.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/baaa4df6284401eb126573eb1c8ea5a88705cc37.1646311858.git.geert+renesas@glider.be

ARM: shmobile: rcar-gen2: Add missing of_node_put()

Fix following coccicheck warning:
./arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c:156:1-33: Function
for_each_matching_node_and_match should have of_node_put() before break
and goto.

Early exits from for_each_matching_node_and_match() should decrement the
node reference counter.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Link: https://lore.kernel.org/r/20211018014503.7598-1-wanjiabing@vivo.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

ARM: shmobile: porter: enable R-Car Gen2 regulator quirk

Porter needs the regulator quirk, just like the other boards.
But unlike the other boards, the Porter uses DA9063L, which
is at 0x5a. Otherwise, DA9063L and DA9210 IRQ line is still
connected to CPU IRQ2 .

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: Fix R-Car Gen2 regulator quirk

The quirk code currently detects all compatible I2C chips with a shared
IRQ line on all I2C busses, adds them into a list, and registers a bus
notifier. For every chip for which the bus notifier triggers, the quirk
code performs I2C transfer on that I2C bus for all addresses in the list.
The problem is that this may generate transfers to non-existing chips on
systems with multiple I2C busses.

This patch adds a check to verify that the I2C bus to which the chip with
shared IRQ is attached to matches the I2C bus of the chip which triggered
the bus notifier and only starts the I2C transfer if they match.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Tested-by: Nguyen Viet Dung <dung.nguyen.aj@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: Rework the PMIC IRQ line quirk

Rather than hard-coding the quirk topology, which stopped scaling,
parse the information from DT. The code looks for all compatible
PMICs -- da9063 and da9210 -- and checks if their IRQ line is tied
to the same pin. If so, the code sends a matching sequence to the
PMIC to deassert the IRQ.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> (on Koelsch)
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: convert to SPDX identifier

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: rcar-gen2: Fix error check in regulator quirk

On systems with two regulators, a bogus error message is printed on
success:

i2c 6-0058: i2c error 2

While adding support for Stout, the number of messages to send was
made variable, but the corresponding return value check of
i2c_transfer() wasn't updated.

Fixes: ff938cd14d67a704 ("ARM: shmobile: stout: enable R-Car Gen2 regulator quirk")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: stout: enable R-Car Gen2 regulator quirk

Regulator setup is suboptimal on H2 Stout too. The Stout newly has
two DA9210 regulators, so the quirk is extended to handle another
DA9210 at i2c address 0x70.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: rcar-gen2: Fix deadlock in regulator quirk

Simon Horman reported that Koelsch and Lager hang during boot, and
bisected this to commit 1c3c5eab171590f8 ("sched/core: Enable
might_sleep() and smp_processor_id() checks early").

The da9063/da9210 regulator quirk for R-Car Gen2 boards uses a bus
notifier, and unregisters the notifier when it is no longer needed.
However, a notifier must not be unregistered from within the call chain.

This bug went unnoticed, as blocking_notifier_chain_unregister() didn't
take the semaphore during early boot. The aforementioned commit changed
that behavior, leading to a deadlock.

Fix this by removing the call to bus_unregister_notifier(), and keeping
local completion state instead.

Reported-by: Simon Horman <horms+renesas@verge.net.au>
Fixes: 663fbb52159cca6f ("ARM: shmobile: R-Car Gen2: Add da9063/da9210 regulator quirk")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: fix regulator quirk for Gen2

The current implementation only works if the da9xxx devices are added
before their drivers are registered. Only then it can apply the fixes to
both devices. Otherwise, the driver for the first device gets probed
before the fix for the second device can be applied. This is what
fails when using the IP core switcher or when having the i2c master
driver as a module.

So, we need to disable both da9xxx once we detected one of them. We now
use i2c_transfer with hardcoded i2c_messages and device addresses, so we
don't need the da9xxx client devices to be instantiated. Because the
fixup is used on specific boards only, the addresses are not going to
change.

Fixes: 663fbb52159cca ("ARM: shmobile: R-Car Gen2: Add da9063/da9210 regulator quirk")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> (r8a7791/koelsch)
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: gose: enable R-Car Gen2 regulator quirk

Regulator setup seems identical to Koelsch.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

ARM: shmobile: R-Car Gen2: Add da9063/da9210 regulator quirk

The r8a7790/lager and r8a7791/koelsch development boards have da9063 and
da9210 regulators. Both regulators have their interrupt request lines
tied to the same interrupt pin (IRQ2) on the SoC.

After cold boot or da9063-induced restart, both the da9063 and da9210
seem to assert their interrupt request lines. Hence as soon as one
driver requests this irq, it gets stuck in an interrupt storm, as it
only manages to deassert its own interrupt request line, and the other
driver hasn't installed an interrupt handler yet.

To handle this, install a quirk that masks the interrupts in both the
da9063 and da9210. This quirk has to run after the i2c master driver
has been initialized, but before the i2c slave drivers are initialized.
As it depends on i2c, select I2C if one of the affected platforms is
enabled in the kernel config.

On koelsch, the following happens:

- Cold boot or reboot using the da9063 restart handler:

IRQ2 is asserted, installing da9063/da9210 regulator quirk
...
i2c i2c-6: regulator_quirk_notify: 1, IRQC_MONITOR = 0x3fb
i2c 6-0058: regulator_quirk_notify: 1, IRQC_MONITOR = 0x3fb
i2c 6-0058: Detected da9063
i2c 6-0058: Masking da9063 interrupt sources
i2c 6-0068: regulator_quirk_notify: 1, IRQC_MONITOR = 0x3fb
i2c 6-0068: Detected da9210
i2c 6-0068: Masking da9210 interrupt sources
i2c 6-0068: IRQ2 is not asserted, removing quirk

- Warm boot (reset button):

rcar_gen2_regulator_quirk: IRQ2 is not asserted, not installing quirk

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>