gpio: 104-idio-16: Migrate to the 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. Migrate the 104-idio-16 module to the new
idio-16 library interface leveraging the gpio-regmap API.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/1f24a1f18c9a9daa4983713e0a5b53e838d624a8.1680618405.git.william.gray@linaro.org/
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-idio-16: Utilize the idio-16 GPIO library

The ACCES 104-IDIO-16 device is part of the ACCES IDIO-16 family, so the
idio-16 GPIO library module is selected and utilized to consolidate
code.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: 104-idio-16: Ensure number of irq matches number of base

The 104-idio-16 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-idio-16: 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-idio-16: Implement and utilize register structures

Reduce magic numbers and improve code readability by implementing and
utilizing named register data structures.

Tested-by: Fred Eckert <Frede@cmslaser.com>
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-idio-16: 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-idio-16: Fix coding style issues

Fixed multiple bare uses of 'unsigned' without int.
Reported by checkpatch.

Signed-off-by: Navin Sankar Velliangiri <navin@linumiz.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: 104-idio-16: 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/20200722105517.186137-1-linus.walleij@linaro.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>

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-idio-16: Implement get_multiple callback

The ACCES I/O 104-IDIO-16 series of devices provides 16
optically-isolated digital inputs accessed via two 8-bit ports. Since
eight input lines are acquired on a single port input read, the
104-IDIO-16 GPIO driver may improve multiple input reads by utilizing a
get_multiple callback. This patch implements the
idio_16_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-idio-16: make use of raw_spinlock variants

The 104-idio-16 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-idio-16: 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-IDIO-16.
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-idio-16: Remove unnecessary driver_data set

Setting driver_data was necessary to access private data in the
idio_16_remove function. Now that the idio_16_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-idio-16: 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 idio_16_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-idio-16: Add set_multiple callback function support

The ACCES 104-IDIO-16 series provides registers where 8 lines of GPIO
may be set at a time. This patch add support for the set_multiple
callback function, thus allowing multiple GPIO output lines to be set
more efficiently in groups.

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

gpio: 104-idio-16: Utilize the ISA bus driver

The ACCES 104-IDIO-16 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-IDIO-16 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-idio-16: Use devm_request_region

By the time request_region is called in the ACCES 104-IDIO-16 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-idio-16: 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-idio-16: Clear pending interrupt in IRQ handler

The ACCES 104-IDIO-16 uses a single interrupt to indicate a possible
change-of-state in any of the digital input lines. As such, only a
single write to the device's "Clear Interrupt" register is necessary to
acknowledge the IRQ for all respective GPIO.

This patch moves the "Clear Interrupt" register write operation from the
irq_ack callback to the IRQ handler function, wherefore each interrupt
may be cleared respectively by executing a single outb call at the end
of the idio_16_irq_handler function, rather than multiple redundant outb
calls as a result of the generic_handle_irq call for each masked GPIO.

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

gpio: 104-idio-16: Disable IRQ on device probe

IRQ should be disabled on device probe so that the device IRQ is in a
known starting state. If IRQ is not disabled, interrupts may be reported
as handled by the IRQ handler, despite no irq_unmask calls made by the
user.

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

gpio: 104-idio-16: Use lowercase symbol names for const variables

To prevent confusion, and to match the existing coding style used in
other GPIO drivers, symbol names within the 104-idio-16 GPIO driver
should be lowercase.

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: Add IRQ support to ACCES 104-IDIO-16 driver

The ACCES 104-IDIO-16 series offers Change-of-State detection interrupt
functionality; if Change-of-State detection is enabled, an interrupt is
fired off if any input line changes state (i.e. goes from low to high,
or from high to low). This patch adds support to handle these interrupts
and allows the user to mask which GPIO lines are affected. The interrupt
line number for the device may be set via the idio_16_irq module
parameter.

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

gpio: change member .dev to .parent

The name .dev in a struct is normally reserved for a struct device
that is let us say a superclass to the thing described by the struct.
struct gpio_chip stands out by confusingly using a struct device *dev
to point to the parent device (such as a platform_device) that
represents the hardware. As we want to give gpio_chip:s real devices,
this is not working. We need to rename this member to parent.

This was done by two coccinelle scripts, I guess it is possible to
combine them into one, but I don't know such stuff. They look like
this:

@@
struct gpio_chip *var;
@@
-var->dev
+var->parent

and:

@@
struct gpio_chip var;
@@
-var.dev
+var.parent

and:

@@
struct bgpio_chip *var;
@@
-var->gc.dev
+var->gc.parent

Plus a few instances of bgpio that I couldn't figure out how
to teach Coccinelle to rewrite.

This patch hits all over the place, but I *strongly* prefer this
solution to any piecemal approaches that just exercise patch
mechanics all over the place. It mainly hits drivers/gpio and
drivers/pinctrl which is my own backyard anyway.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Rafał Miłecki <zajec5@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Alek Du <alek.du@intel.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Add GPIO support for the ACCES 104-IDIO-16

The ACCES 104-IDIO-16 family of PC/104 utility boards feature 16
optically isolated inputs and 16 optically isolated FET solid state
outputs. This driver provides GPIO support for these 32 channels of
digital I/O. Change-of-State detection interrupts are not supported.

GPIO 0-15 correspond to digital outputs 0-15, while GPIO 16-31
correspond to digital inputs 0-15. The base port address for the device
may be set via the idio_16_base module parameter.

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