gpio: sifive: remove unneeded call to platform_set_drvdata()

This function call was found to be unnecessary as there is no equivalent
platform_get_drvdata() call to access the private data of the driver. Also,
the private data is defined in this driver, so there is no risk of it being
accessed outside of this driver file.

Reviewed-by: Alexandru Ardelean <alex@shruggie.ro>
Signed-off-by: Andrei Coardos <aboutphysycs@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: Allow building the driver as a module

This can reduce the kernel image size in multiplatform configurations.

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: Get the parent IRQ's domain from its irq_data

Do not parse the devicetree again when the data is already available
from the IRQ subsystem. This follows the example of the ThunderX and
X-Gene GPIO drivers. The ngpio check is needed to avoid a possible
out-of-bounds read.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: Look up IRQs only once during probe

of_irq_count(), or eqivalently platform_irq_count(), simply looks up
successively-numbered IRQs until that fails. Since this driver needs to
look up each IRQ anyway to get its virq number, use that existing loop
to count the IRQs at the same time.

The check against SIFIVE_GPIO_MAX functioned as a bounds check for
chip->irq_number. That is now handled by the loop condition.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: Directly use the device's fwnode

There is no need to convert dev->of_node back to a fwnode_handle.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: Support IRQ wake

Each pin drives a separate interrupt in the parent IRQ domain, so there
is no need to set IRQCHIP_MASK_ON_SUSPEND.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: add missing check for platform_get_irq

Add the missing check for platform_get_irq() and return error code
if it fails.

The returned error code will be dealed with in
builtin_platform_driver(sifive_gpio_driver) and the driver will not
be registered.

Fixes: f52d6d8b43e5 ("gpio: sifive: To get gpio irq offset from device tree data")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: drop of_match_ptr for ID table

The driver can match only via the DT table so the table should be always
used and the of_match_ptr does not have any sense (this also allows ACPI
matching via PRP0001, even though it might not be relevant here).

drivers/gpio/gpio-sifive.c:263:34: error: ‘sifive_gpio_match’ defined but not used [-Werror=unused-const-variable=]

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: Fix refcount leak in sifive_gpio_probe

of_irq_find_parent() returns a node pointer with refcount incremented,
We should use of_node_put() on it when not needed anymore.
Add missing of_node_put() to avoid refcount leak.

Fixes: 96868dce644d ("gpio/sifive: Add GPIO driver for SiFive SoCs")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: sifive: Make the irqchip immutable

Commit 6c846d026d49 ("gpio: Don't fiddle with irqchips marked as
immutable") added a warning to indicate if the gpiolib is altering the
internals of irqchips. Following this change the following warning is
now observed for the sifive driver:

gpio gpiochip1: (38001000.gpio-controller): not an immutable chip, please consider fixing it!

Fix this by making the irqchip in the sifive driver immutable.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: use raw spinlock for gpio chip shadowed data

In case of PREEMPT_RT, there is a raw_spinlock -> spinlock dependency
as the lockdep report shows.

__irq_set_handler
irq_get_desc_buslock
__irq_get_desc_lock
raw_spin_lock_irqsave(&desc->lock, *flags); // raw spinlock get here
__irq_do_set_handler
mask_ack_irq
dwapb_irq_ack
spin_lock_irqsave(&gc->bgpio_lock, flags); // sleep able spinlock
irq_put_desc_busunlock

Replace with a raw lock to avoid BUGs. This lock is only used to access
registers, and It's safe to replace with the raw lock without bad
influence.

[ 15.090359][ T1] =============================
[ 15.090365][ T1] [ BUG: Invalid wait context ]
[ 15.090373][ T1] 5.10.59-rt52-00983-g186a6841c682-dirty #3 Not tainted
[ 15.090386][ T1] -----------------------------
[ 15.090392][ T1] swapper/0/1 is trying to lock:
[ 15.090402][ T1] 70ff00018507c188 (&gc->bgpio_lock){....}-{3:3}, at: _raw_spin_lock_irqsave+0x1c/0x28
[ 15.090470][ T1] other info that might help us debug this:
[ 15.090477][ T1] context-{5:5}
[ 15.090485][ T1] 3 locks held by swapper/0/1:
[ 15.090497][ T1] #0: c2ff0001816de1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock+0x98/0x104
[ 15.090553][ T1] #1: ffff90001485b4b8 (irq_domain_mutex){+.+.}-{4:4}, at: irq_domain_associate+0xbc/0x6d4
[ 15.090606][ T1] #2: 4bff000185d7a8e0 (lock_class){....}-{2:2}, at: _raw_spin_lock_irqsave+0x1c/0x28
[ 15.090654][ T1] stack backtrace:
[ 15.090661][ T1] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.10.59-rt52-00983-g186a6841c682-dirty #3
[ 15.090682][ T1] Hardware name: Horizon Robotics Journey 5 DVB (DT)
[ 15.090692][ T1] Call trace:
......
[ 15.090811][ T1] _raw_spin_lock_irqsave+0x1c/0x28
[ 15.090828][ T1] dwapb_irq_ack+0xb4/0x300
[ 15.090846][ T1] __irq_do_set_handler+0x494/0xb2c
[ 15.090864][ T1] __irq_set_handler+0x74/0x114
[ 15.090881][ T1] irq_set_chip_and_handler_name+0x44/0x58
[ 15.090900][ T1] gpiochip_irq_map+0x210/0x644

Signed-off-by: Schspa Shi <schspa@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Doug Berger <opendmb@gmail.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: sifive: use the correct register to read output values

Setting the output of a GPIO to 1 using gpiod_set_value(), followed by
reading the same GPIO using gpiod_get_value(), will currently yield an
incorrect result.

This is because the SiFive GPIO device stores the output values in reg_set,
not reg_dat.

Supply the flag BGPIOF_READ_OUTPUT_REG_SET to bgpio_init() so that the
generic driver reads the correct register.

Fixes: 96868dce644d ("gpio/sifive: Add GPIO driver for SiFive SoCs")
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
[Bartosz: added the Fixes tag]
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: sifive: Set affinity callback to parent

This assigns the .irq_set_affinity to the parent callback.
I assume the sifive GPIO can be used in systems with
SMP.

I used the pattern making the hirerarchy tolerant for missing
parent as in Marc's earlier patches.

Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Yash Shah <yash.shah@sifive.com>
Cc: Wesley W. Terpstra <wesley@sifive.com>
Link: https://lore.kernel.org/r/20201117213351.249668-1-linus.walleij@linaro.org

gpio: sifive: To get gpio irq offset from device tree data

We can get hwirq number of the gpio by its irq_data->hwirq so that we don't
need to add more macros for different platforms. This patch is tested in
SiFive Unleashed board and SiFive Unmatched board.

Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: sifive: Fix SiFive gpio probe

Fix the check on the number of IRQs to allow up to the maximum (32)
instead of only the maximum minus one.

Fixes: 96868dce644d ("gpio/sifive: Add GPIO driver for SiFive SoCs")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Link: https://lore.kernel.org/r/20201107081420.60325-10-damien.lemoal@wdc.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: sifive: fix static checker warning

Typcasting "irq_state" leads to the below static checker warning:
The fix is to declare "irq_state" as unsigned long instead of u32.

drivers/gpio/gpio-sifive.c:97 sifive_gpio_irq_enable()
warn: passing casted pointer '&chip->irq_state' to
'assign_bit()' 32 vs 64.

Fixes: 96868dce644d ("gpio/sifive: Add GPIO driver for SiFive SoCs")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Link: https://lore.kernel.org/r/1580189061-14091-1-git-send-email-yash.shah@sifive.com
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio/sifive: Add GPIO driver for SiFive SoCs

Adds the GPIO driver for SiFive RISC-V SoCs.

Signed-off-by: Wesley W. Terpstra <wesley@sifive.com>
[Atish: Various fixes and code cleanup]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/1575976274-13487-6-git-send-email-yash.shah@sifive.com