If we failed to create the top debugfs directory, we must not try to
create the child nodes. We currently only check if gpio_mockup_dbg_dir
is not NULL, but it can also contain an errno if debugfs is disabled
in build options. Use IS_ERR_OR_NULL() instead.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Bamvor changed his mail so let's updat his mail address
everywhere.

Cc: Bamvor Jian Zhang <bamv2005@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The return value of platform_device_register_resndata() on error is
an error code converted to pointer with ERR_PTR(), not NULL.

Check the return value correctly.

Fixes: 8a39f597 ("gpio: mockup: rework device probing")
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to avoid repeating the calculations on every access - add
helpers for gpio base and ngpio components of the ranges array.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This variable holds the number of mockup GPIO ranges so rename it
accordingly.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

As discussed with Marc Zyngier: irq_sim_init() and its devres variant
should return the base of the allocated interrupt range on success
rather than 0. This will be modified later - first, change the way
users handle the return value of these routines.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Implement the set_multiple() callback and register it with the gpiolib
framework. This is only meant to also test the internal kernel API.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Minor readability tweak: prefer breaking the lines in a way where the
second part is longer than the first.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Improve the module params sanitization: bail out from init if the user
tries to pass a non-positive number of GPIO lines for any mockup chip.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The debugfs routines returning pointers can return NULL or error codes
embedded with ERR_PTR(). Check the return values with IS_ERR_OR_NULL().

While we're at it: make the error message more specific so it's not
confused with the one emitted when the top-level gpio-mockup debugfs
directory creation fails.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Keep GPIO chip callbacks, event trigger callbacks and mockup chip
setup code visibly separated. We're mostly good - just need to move
the line naming routine below.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

GPIO values are universally represented as integers. Change the type
of the variable storing the current line value to int for consistency.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently each chip has a dedicated directory in debugfs for event
triggers. We use the chip's label for the directory name, but the user
can't really associate these directories with chip names without
parsing the relevant sysfs entries.

Use chip names for directory names. For backward compatibility: create
links pointing to the actual directories named using the chip labels.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Move the last bits of code dealing with module parameters to the init
function. Add a new variable to platform data, which indicates to the
probe function if it should name the GPIO lines. If we ever want to
make the line naming more fine-grained (e.g. per chip switch) it will
be easier this way.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Now that the probe() function only does what is should, there's no
need to split the chip adding logic into a separate routine. Merge
gpio_mockup_add() into gpio_mockup_probe().
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Minor coding style fix.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Visually shrink the pr_err() calls by encapsulating adding the module
name prefix to the message in a macro.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We currently create a single platform device in init and then parse
the configuration passed to us via module parameters in probe() before
creating GPIO chips and registering them with the gpiolib framework.

The relation between platform devices and mockup chips should be 1:1.

Create a separate platform device for each mockup chip using convenient
helpers (platform_device_register_resndata()). Pass a platform data
structure to probe() in which the configuration (GPIO base, number of
lines, chip index) extracted from the module params is stored. Make
probe() create a single mockup chip for every platform device.

This approach has several advantages:
- we only parse the module parameters in init() and can bail out before
  attaching any device if the input is invalid (currently we would
  have to examine kernel logs),
- we'll get notified by the device framework about errors in probe()
  for specific chips,
- probe() gets simplified and only does what it's supposed to.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The number of supported mockup chips is limited. Check this limit when
parsing the module parameters.

Also: make sure that each chip is described with a <base - ngpio> pair.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

If the module parameters are invalid, we should bail out from the init
function instead of detecting it during the device probe. That way we
don't even allow the user to load the module if we don't accept the
arguments.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add the gpio_mockup_ prefix to the remaining symbols that still don't
have it, so that the entire driver code is consistent.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The variable gc is assigned but never read and is redundant. Remove it.
Cleans up clang warning:

drivers/gpio/gpio-mockup.c:169:2: warning: Value stored to 'gc' is never read
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Shrink the driver by removing the code dealing with dummy interrupts
and replacing it with calls to the irq_sim API.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Acked-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When allocating a zeroed array of objects use devm_kcalloc() instead
of manually calculating the required size and using devm_kzalloc().
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Just taking credit for the recent changes and new features. :)
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Indicate the error number and make the message a bit more elaborate.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When the requested number of GPIO lines is 0, return -EINVAL, not
-1 which is -EPERM.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We currently shift bits here and there without actually explaining
what we're doing. Add some helper variables with names indicating
their purpose to improve the code readability.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently we ignore the last odd range value, since each chip is
described by two values. Be more strict and require the user to
pass an even number of ranges.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Invert the logic of the irq_enabled check and only access the private
data after the input is sanitized.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We're currently only checking the first character of the input to the
debugfs event files, so a string like '0sdfdsf' is valid and indicates
a falling edge event.

Be more strict and only allow '0', '1', '0\n' & '1\n'.

While we're at it: move the sanitization code before the irq_enabled
check so that we indicate an error on invalid input even if nobody is
waiting for events.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Even though this is a testing module, be nice and actually implement
these functions.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When inserting and removing the module repeatedly (e.g. when running
the libgpiod test-suite) the kernel log gets clobbered with messages
reporting successful creation of dummy gpiochips.

Remove this message and only emit logs when something bad happens.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

All internal symbols except for the direction enum follow the same
convention and use the gpio_mockup prefix. Add the prefix to the
DIR_IN and DIR_OUT definitions as well for consistency across the
file.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The comment in linux/gpio/driver.h says:

 @get_direction: returns direction for signal "offset", 0=out, 1=in

We got those switched at some point. Fix the values.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use the resource managed variant of irq_alloc_descs(). This allows us
to remove gpio_mockup_remove().
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NBamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

copy_from_user() returns the number of bytes remaining to be copied but
we want to return negative error codes on failue.

Fixes: 9202ba23 ("gpio: mockup: implement event injecting over debugfs")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Create a debugfs directory for every mockup chip and a single file
for every line. Writing (0 or 1) to these files allows the user to
inject line events (falling or rising edge respectively).
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Setup a dummy irqchip that will allow us to inject line events for
testing purposes.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to allow testing line lookup by name from user space, add
a new boolean parameter that indicates whether we want the lines to
be named. The name is created by concatenating the chip name and the
line offset value.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>