gpio: aspeed-sgpio: Convert to immutable irq_chip

Convert the driver to immutable irq-chip with a bit of
intuition.

Cc: Marc Zyngier <maz@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

kbuild, gpio: gpio-aspeed-sgpio: remove MODULE_LICENSE in non-modules

Since commit 8b41fc4454e ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.

So remove it in the files in this commit, none of which can be built as
modules.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Joel Stanley <joel@jms.id.au>
Cc: linux-gpio@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-aspeed@lists.ozlabs.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: aspeed-sgpio: Convert aspeed_sgpio.lock to raw_spinlock

The gpio-aspeed-sgpio driver implements an irq_chip which need to be
invoked from hardirq context. Since spin_lock() can sleep with
PREEMPT_RT, it is no longer legal to invoke it while interrupts are
disabled.
This also causes lockdep to complain about:
[ 25.919465] [ BUG: Invalid wait context ]
because aspeed_sgpio.lock (spin_lock_t) is taken under irq_desc.lock
(raw_spinlock_t).
Let's use of raw_spinlock_t instead of spinlock_t.

Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: gpio-aspeed-sgpio: Fix wrong hwirq base in irq handler

Each aspeed sgpio bank has 64 gpio pins(32 input pins and 32 output pins).
The hwirq base for each sgpio bank should be multiples of 64 rather than
multiples of 32.

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: gpio-aspeed-sgpio: Fix wrong hwirq in irq handler.

The current hwirq is calculated based on the old GPIO pin order(input
GPIO range is from 0 to ngpios - 1).
It should be calculated based on the current GPIO input pin order(input
GPIOs are 0, 2, 4, ..., (ngpios - 1) * 2).

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: gpio-aspeed-sgpio: Return error if ngpios is not multiple of 8.

Add an else-if condition in the probe function to check whether ngpios is
multiple of 8.
Per AST datasheet, numbers of available serial GPIO pins in Serial GPIO
Configuration Register must be n bytes. For instance, if n = 1, it means
AST SoC supports 8 GPIO pins.

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: gpio-aspeed-sgpio: Use generic device property APIs

Replace all of_property_read_u32() with device_property_read_u32().

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: gpio-aspeed-sgpio: Move irq_chip to aspeed-sgpio struct

The current design initializes irq->chip from a global irqchip struct,
which causes multiple sgpio devices use the same irq_chip.
The patch moves irq_chip to aspeed_sgpio struct for initializing
irq_chip from their private gpio struct.

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: gpio-aspeed-sgpio: Add set_config function

AST SoC supports *retain pin state* function when wdt reset.
The patch adds set_config function for handling sgpio reset tolerance
register.

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: gpio-aspeed-sgpio: Add AST2600 sgpio support

The maximum number of gpio pins of SoC is hardcoded as 80 and the gpio pin
count mask for GPIO Configuration register is hardcode as GENMASK(9,6).
However, AST2600 has 2 sgpio master interfaces, one of them supports up
to 128 gpio pins and pin count mask of GPIO Configuration Register is 5
bits.

The patch adds ast2600 compatibles, removes MAX_NR_HW_SGPIO and
corresponding design to make the gpio input/output pin base are determined
by ngpios.
The patch also removed hardcoded pin mask and adds ast2400, ast2500,
ast2600 platform data that include gpio pin count mask for GPIO
Configuration Register.

The original pin order is as follows:
(suppose MAX_NR_HW_SGPIO is 80 and ngpios is 10 as well)
Input:
0 1 2 3 ... 9
Output:
80 81 82 ... 89

The new pin order is as follows:
Input:
0 2 4 6 ... 18
Output:
1 3 5 7 ... 19

SGPIO pin id and input/output pin mapping is as follows:
SGPIO0(0,1), SGPIO1(2,3), ..., SGPIO79(158,159)

For example:
Access SGPIO5(10,11)
Get SGPIO pin 5 (suppose sgpio chip id is 2)
gpioget 2 10

Set SGPIO pin 5 (suppose sgpio chip id is 2)
gpioset 2 11=1
gpioset 2 11=0

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: Bulk conversion to generic_handle_domain_irq()

Wherever possible, replace constructs that match either
generic_handle_irq(irq_find_mapping()) or
generic_handle_irq(irq_linear_revmap()) to a single call to
generic_handle_domain_irq().

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>

gpio/aspeed-sgpio: don't enable all interrupts by default

Currently, the IRQ setup for the SGPIO driver enables all interrupts in
dual-edge trigger mode. Since the default handler is handle_bad_irq, any
state change on input GPIOs will trigger bad IRQ warnings.

This change applies sensible IRQ defaults: single-edge trigger, and all
IRQs disabled.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Fixes: 7db47faae79b ("gpio: aspeed: Add SGPIO driver")
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio/aspeed-sgpio: enable access to all 80 input & output sgpios

Currently, the aspeed-sgpio driver exposes up to 80 GPIO lines,
corresponding to the 80 status bits available in hardware. Each of these
lines can be configured as either an input or an output.

However, each of these GPIOs is actually an input *and* an output; we
actually have 80 inputs plus 80 outputs.

This change expands the maximum number of GPIOs to 160; the lower half
of this range are the input-only GPIOs, the upper half are the outputs.
We fix the GPIO directions to correspond to this mapping.

This also fixes a bug when setting GPIOs - we were reading from the
input register, making it impossible to set more than one output GPIO.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Fixes: 7db47faae79b ("gpio: aspeed: Add SGPIO driver")
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

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>

gpio: aspeed-sgpio: fixed typos

This fixes some various typos.

Signed-off-by: Sachin Agarwal <asachin591@gmail.com>
Link: https://lore.kernel.org/r/20200118105319.68637-1-sachinagarwal@sachins-MacBook-2.local
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: aspeed: avoid return type warning

gcc has a hard time tracking whether BUG_ON(1) ends
execution or not:

drivers/gpio/gpio-aspeed-sgpio.c: In function 'bank_reg':
drivers/gpio/gpio-aspeed-sgpio.c:112:1: error: control reaches end of non-void function [-Werror=return-type]

Use the simpler BUG() that gcc knows cannot continue.

Fixes: f8b410e3695a ("gpio: aspeed-sgpio: Rename and add Kconfig/Makefile")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: aspeed-sgpio: Rename and add Kconfig/Makefile

This renames the "gpio-aspeed" driver to conform with other
GPIO drivers as "gpio-aspeed-sgpio.c". All GPIO drivers
should start with the string "gpio-" no special exceptions.

Also the Kconfig and Makefile entries should normally
go with the driver but I missed this in my review, sorry
for mistake. "CONFIG_GPIO_ASPEED_SGPIO" is used to
activate this driver.

Cc: Hongwei Zhang <hongweiz@ami.com>
Fixes: 7db47faae79b ("gpio: aspeed: Add SGPIO driver")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20190927114833.12551-1-linus.walleij@linaro.org