gpio: 104-idi-48: Enable use_raw_spinlock for idi48_regmap_config

The idi48 regmap can be used in an interrupt context by regmap-irq. To
prevent a deadlock, enable use_raw_spinlock for idi48_regmap_config.

Fixes: e28432a77365 ("gpio: 104-idi-48: Migrate to the regmap-irq API")
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: 104-idi-48: Migrate to gpio-regmap API

The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver. Despite the underlying interface being based on
i8255, it is simpler to use the gpio-regmap API directly because the
104-IDI-48 device features only input signals. Therefore, the dependence
on the i8255 GPIO library is removed in this patch.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: 104-idi-48: Migrate to the regmap-irq API

The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver.

For the 104-idi-48, we get an IRQ register with some status information
and basic masking, but it's broken down by banks rather than individual
GPIO. There are six banks (8 GPIO lines each) that correspond to the
lower six bits of the IRQ register (bits 0-5):

Base Address + 7 (Read): IRQ Status Register/IRQ Clear
Bit 0-5: Respective Bank IRQ Statuses
Bit 6: IRQ Status (Active Low)
Bit 7: IRQ Enable Status
Base Address + 7 (Write): IRQ Enable/Disable
Bit 0-5: Respective Bank IRQ Enable/Disable

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: 104-idi-48: Ensure number of irq matches number of base

The 104-idi-48 module calls devm_request_irq() for each device. If the
number of irq passed to the module does not match the number of base, a
default value of 0 is passed to devm_request_irq(). IRQ 0 is probably
not what the user wants, so utilize the module_isa_driver_with_irq macro
to ensure the number of irq matches the number of base.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: 104-idi-48: Make irq_chip immutable

Kernel warns about mutable irq_chips:

"not an immutable chip, please consider fixing!"

Make the struct irq_chip const, flag it as IRQCHIP_IMMUTABLE, add the
new helper functions, and call the appropriate gpiolib functions.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: 104-idi-48: Implement and utilize register structures

Reduce magic numbers and improve code readability by implementing and
utilizing named register data structures. The 104-IDI-48 device features
an Intel 8255 compatible GPIO interface, so the i8255 GPIO module is
selected and utilized as well.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: John Hentges <jhentges@accesio.com>
Cc: Jay Dolan <jay.dolan@accesio.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: 104-idi-48: unsigned to unsigned int cleanup

Remove checkpatch warnings. No functional changes.

Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: 104-idi-48: Utilize iomap interface

This driver doesn't need to access I/O ports directly via inb()/outb()
and friends. This patch abstracts such access by calling ioport_map()
to enable the use of more typical ioread8()/iowrite8() I/O memory
accessor calls.

Suggested-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

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: 104-idi-48: improve code indentation

Address code indentation warning messages by checkpatch script. Combine
split function parameters on one line. This also resolves the "use tabs
instead of space" warning by checkpatch script.

Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>

Link: https://lore.kernel.org/r/20201013190212.GA85788@ubuntu204
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Use irqchip template

This makes the driver use the irqchip template to assign
properties to the gpio_irq_chip instead of using the
explicit call to gpiochip_irqchip_add().

The irqchip is instead added while adding the gpiochip.
Also move the IRQ initialization to the special .init_hw()
callback.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20200722104820.174654-1-linus.walleij@linaro.org

gpio: 104-idi-48: utilize for_each_set_clump8 macro

Replace verbose implementation in get_multiple/set_multiple callbacks
with for_each_set_clump8 macro to simplify code and improve clarity.

Link: http://lkml.kernel.org/r/b0631b6d489f85008480399df283ccd33ecfe310.1570641097.git.vilhelm.gray@gmail.com
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Morten Hein Tiljeset <morten.tiljeset@prevas.dk>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: Use new GPIO_LINE_DIRECTION

It's hard for occasional GPIO code reader/writer to know if values 0/1
equal to IN or OUT. Use defined GPIO_LINE_DIRECTION_IN and
GPIO_LINE_DIRECTION_OUT to help them out.

NOTE - for gpio-amd-fch and gpio-bd9571mwv:
This commit also changes the return value for direction get to equal 1
for direction INPUT. Prior this commit these drivers might have
returned some other positive value but 1 for INPUT.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48e: make array register_offset static, makes object smaller

Don't populate the array register_offset on the stack but instead make it
static. Makes the object code smaller by 63 bytes. Also add the int type
specifier to clean up a checkpatch warning.

Before:
text data bss dec hex filename
9212 5712 1408 16332 3fcc drivers/gpio/gpio-104-idi-48.o

After:
text data bss dec hex filename
9085 5776 1408 16269 3f8d drivers/gpio/gpio-104-idi-48.o

(gcc version 9.2.1, amd64)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpio: 104-idi-48e: Mask the read inputs for get_multiple

This patch masks the read inputs with the word mask in order to ensure
only requested input states are returned in the bits array.

Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: make several const arrays static, shrinks object size

Don't populate the const read-only arrays 'port' on the stack but
instead make them static. Makes the object code smaller:

Before:
text data bss dec hex filename
8542 4088 672 13302 33f6 drivers/gpio/gpio-gpio-mm.o
10959 4952 832 16743 4167 drivers/gpio/gpio-104-dio-48e.o
9022 5064 1408 15494 3c86 drivers/gpio/gpio-104-idi-48.o

After:
text data bss dec hex filename
8372 4144 672 13188 3384 drivers/gpio/gpio-gpio-mm.o
10790 5008 832 16630 40f6 drivers/gpio/gpio-104-dio-48e.o
8853 5152 1408 15413 3c35 linux/drivers/gpio/gpio-104-idi-48.o

(gcc version 7.2.0 x86_64)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Implement get_multiple callback

The ACCES I/O 104-IDI-48 series of devices provides 48
optically-isolated inputs accessed via six 8-bit ports. Since eight
input lines are acquired on a single port input read, the 104-IDI-48
GPIO driver may improve multiple input reads by utilizing a get_multiple
callback. This patch implements the idi_48_gpio_get_multiple function
which serves as the respective get_multiple callback.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Move irqdomain into struct gpio_irq_chip

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Annotate hardware config module parameters in drivers/gpio/

When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image. Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.

To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify. The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.

Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.

This patch annotates drivers in drivers/gpio/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
cc: Alexandre Courbot <gnurou@gmail.com>
cc: linux-gpio@vger.kernel.org

gpio: 104-idi-48: make use of raw_spinlock variants

The 104-idi-48 gpio driver currently implements 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>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Add support for GPIO names

This patch sets the gpio_chip names option with an array of GPIO line
names that match the manual documentation for the ACCES 104-IDI-48.
This should make it easier for users to identify which GPIO line
corresponds to a respective GPIO pin on the device.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Remove unnecessary driver_data set

Setting driver_data was necessary to access private data in the
idi_48_remove function. Now that the idi_48_remove function is gone,
driver_data is no longer used. This patch removes the relevant code.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Utilize devm_ functions in driver probe callback

The devm_ resource manager functions allow memory to be automatically
released when a device is unbound. This patch takes advantage of the
resource manager functions and replaces the gpiochip_add_data call and
request_irq call with the devm_gpiochip_add_data call and
devm_request_irq call respectively. In addition, the idi_48_remove
function has been removed as no longer necessary due to the use of the
relevant devm_ resource manager functions.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Fix missing spin_lock_init for ack_lock

Fixes: 9ae482104cb9 ("gpio: 104-idi-48: Clear pending interrupt once in IRQ handler")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Fix missing spin_lock_init for ack_lock

Fixes: 9ae482104cb9 ("gpio: 104-idi-48: Clear pending interrupt once in IRQ handler")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Utilize the ISA bus driver

The ACCES 104-IDI-48 series communicates via the ISA bus. As such, it
is more appropriate to use the ISA bus driver over the platform driver
to control the ACCES 104-IDI-48 GPIO driver.

This patch also adds support for multiple devices via the base and irq
module array parameters. Each element of the base array corresponds to a
discrete device; each element of the irq array corresponds to the
respective device addressed in the respective base array element.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpio: 104-idi-48: Use devm_request_region

By the time request_region is called in the ACCES 104-IDI-48 GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: misc: Pass correct license string to MODULE_LICENSE

The GPIO driver copyright boilerplate lacks the "or
later" verbiage regarding GPL compliant distribution. The MODULE_LICENSE
string should reflect the actual copyright license terms used.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Allow IRQ sharing

The ACCES 104-IDI-48 can differentiate between its own and other
devices' interrupt requests. Therefore, IRQ sharing is possible and
should be permitted.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: use gpiochip data pointer

This makes the driver use the data pointer added to the gpio_chip
to store a pointer to the state container instead of relying on
container_of().

Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 104-idi-48: Clear pending interrupt once in IRQ handler

Performing a read operation on the IRQ Status register will clear the
IRQ latch. Since a read operation on the IRQ Status register must be
performed in the IRQ handler in order to determine if the IRQ was in
fact generated by the device, the IRQ latch is consequently cleared by
the IRQ handler. A spinlock is used to guarantee that each IRQ is
serviced in the order it was received.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>

gpio: Add GPIO support for the ACCES 104-IDI-48

The ACCES 104-IDI-48 family of PC/104 utility boards feature 48
individually optically isolated digital inputs. Enabled inputs feature
change-of-state detection capability; if change-of-state detection is
enabled, an interrupt is fired off if a change of input level
(low-to-high or high-to-low) is detected. Change-of-state IRQs are
enabled/disabled on 8-bit boundaries, for a total of six boundaries.

This driver provides GPIO and IRQ support for these 48 channels of
digital input. The base port address for the device may be configured
via the idi_48_base module parameter. The interrupt line number for the
device may be configured via the idi_48_irq module parameter.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>