gpio: eic-sprd: Optimize the calculation method of eic number

The num_eics is a default value, but some SoCs support more than 8.
In order to adapt to all projects, the total number of eics is
automatically calculated through dts.

Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com>
Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: eic-sprd: Clear interrupt after set the interrupt type

The raw interrupt status of eic maybe set before the interrupt is enabled,
since the eic interrupt has a latch function, which would trigger the
interrupt event once enabled it from user side. To solve this problem,
interrupts generated before setting the interrupt trigger type are ignored.

Fixes: 25518e024e3a ("gpio: Add Spreadtrum EIC driver support")
Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: eic-sprd: use a helper variable for &pdev->dev

Instead of dereferencing pdev everywhere, just store the address of the
underlying struct device in a local variable.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

gpio: eic-sprd: unregister from the irq notifier on remove()

This is a tristate module, it can be unloaded. We need to cleanup properly
and unregister from the interrupt notifier on driver detach.

Fixes: b32415652a4d ("gpio: eic-sprd: use atomic notifiers to notify all chips about irqs")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

gpio: eic-sprd: use atomic notifiers to notify all chips about irqs

Calling gpiochip_find() from interrupt handler in this driver is an
abuse of the GPIO API. It only happens to work because nobody added a
might_sleep() to it and the lock used by GPIOLIB is a spinlock.

Both will soon be changed as we're limiting both the number of
interfaces allowed to be called from atomic context as well as making
struct gpio_chip private to the GPIO code that owns it. We'll also
switch to protecting the global GPIO device list with a mutex as there
is no reason to allow changes to it from interrupt handlers.

Instead of iterating over all SPRD chips and looking up each
corresponding GPIO chip, let's make each SPRD GPIO controller register
with a notifier chain. The chain will be called at interrupt so that
every chip that already probed will be notified. The rest of the
interrupt handling remains the same. This should result in faster code as
we're avoiding iterating over the list of all GPIO devices.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Chunyan Zhang <zhang.lyra@gmail.com>
Tested-by: Wenhua Lin <wenhua.lin@unisoc.com>

gpio: eic-sprd: remove unneeded platform_set_drvdata() call

The platform_set_drvdata() call was never used, ever since the driver was
originally added.
It looks like this copy+paste left-over. Possibly the author copied from a
driver that had this line, but also had a remove hook.

Reviewed-by: Alexandru Ardelean <alex@shruggie.ro>
Signed-off-by: Andrei Coardos <aboutphysycs@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: eic-sprd: Make the irqchip immutable

Remove the irq_chip from pmic_eic structure,
use the various calls by defining the statically
irq_chip structure.

Signed-off-by: Cixi Geng <cixi.geng1@unisoc.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: Get rid of duplicate of_node assignment in the drivers

GPIO library does copy the of_node from the parent device of
the GPIO chip, there is no need to repeat this in the individual
drivers. Remove these assignment all at once.

For the details one may look into the of_gpio_dev_init() implementation.

While at it, remove duplicate parent device assignment where it is the case.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-By: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: eic-sprd: break loop when getting NULL device resource

EIC controller have unfixed numbers of banks on different Spreadtrum SoCs,
and each bank has its own base address, the loop of getting there base
address in driver should break if the resource gotten via
platform_get_resource() is NULL already. The later ones would be all NULL
even if the loop continues.

Fixes: 25518e024e3a ("gpio: Add Spreadtrum EIC driver support")
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20201209055106.840100-1-zhang.lyra@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Revert "gpio: eic-sprd: Use devm_platform_ioremap_resource()"

This reverts commit 0f5cb8cc27a266c81e6523b436479802e9aafc9e.

This commit will cause below warnings, since our EIC controller can support
differnt banks on different Spreadtrum SoCs, and each bank has its own base
address, we will get invalid resource warning if the bank number is less than
SPRD_EIC_MAX_BANK on some Spreadtrum SoCs.

So we should not use devm_platform_ioremap_resource() here to remove the
warnings.

[ 1.118508] sprd-eic 40210000.gpio: invalid resource
[ 1.118535] sprd-eic 40210000.gpio: invalid resource
[ 1.119034] sprd-eic 40210080.gpio: invalid resource
[ 1.119055] sprd-eic 40210080.gpio: invalid resource
[ 1.119462] sprd-eic 402100a0.gpio: invalid resource
[ 1.119482] sprd-eic 402100a0.gpio: invalid resource
[ 1.119893] sprd-eic 402100c0.gpio: invalid resource
[ 1.119913] sprd-eic 402100c0.gpio: invalid resource

Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Link: https://lore.kernel.org/r/8d3579f4b49bb675dc805035960f24852898be28.1585734060.git.baolin.wang7@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: eic: sprd: Fix the incorrect EIC offset when toggling

When toggling the level trigger to emulate the edge trigger, the
EIC offset is incorrect without adding the corresponding bank index,
thus fix it.

Fixes: 7bf0d7f62282 ("gpio: eic: Add edge trigger emulation for EIC")
Cc: stable@vger.kernel.org
Signed-off-by: Bruce Chen <bruce.chen@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: Remove dev_err() usage after platform_get_irq()

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: linux-gpio@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190730181557.90391-16-swboyd@chromium.org
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: eic-sprd: Use devm_platform_ioremap_resource()

Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Reviewed-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: eic: sprd: Fix incorrect irq type setting for the sync EIC

When setting sync EIC as IRQ_TYPE_EDGE_BOTH type, we missed to set the
SPRD_EIC_SYNC_INTMODE register to 0, which means detecting edge signals.

Thus this patch fixes the issue.

Fixes: 25518e024e3a ("gpio: Add Spreadtrum EIC driver support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: sprd: Add missing break in switch statement

Fix the following warning by adding a missing break:

drivers/gpio/gpio-eic-sprd.c: In function ‘sprd_eic_irq_set_type’:
drivers/gpio/gpio-eic-sprd.c:403:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
switch (flow_type) {
^~~~~~
drivers/gpio/gpio-eic-sprd.c:435:2: note: here
default:
^~~~~~~

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: sprd: Fix incorrect irq type setting for the async EIC

When setting async EIC as IRQ_TYPE_EDGE_BOTH type, we missed to set the
SPRD_EIC_ASYNC_INTMODE register to 0, which means detecting edge signals.

Thus this patch fixes the issue.

Fixes: 25518e024e3a ("gpio: Add Spreadtrum EIC driver support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Neo Hou <neo.hou@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: sprd: Fix the incorrect data register

Since differnt type EICs have its own data register to read, thus fix the
incorrect data register.

Fixes: 25518e024e3a ("gpio: Add Spreadtrum EIC driver support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Neo Hou <neo.hou@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: eic: Add edge trigger emulation for EIC

The Spreadtrum debounce EIC and latch EIC can not support edge trigger,
but most GPIO users (like gpio-key driver) only use the edge trigger,
thus the EIC driver need add some support to emulate the edge trigger
to satisfy this requirement.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Add Spreadtrum EIC driver support

The Spreadtrum digital-chip EIC controller has 4 sub-modules: debounce EIC,
latch EIC, async EIC and sync EIC, and each sub-module can has multiple
banks and each bank contains 8 EICs.

Each EIC can only be used as input mode, and has the capability to trigger
interrupts when detecting input signals.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>