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>

Moving a couple of lines around allows us to shrink the code a bit
while keeping the same functionality.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The following patch tries to improve the readability of the mockup
driver.

The driver is called gpio-mockup, so add the same prefix to all
functions and structures.

Add some newlines and use a temporary pointer in gpio_mockup_add().

Drop the name of the direction enum and rename the enum values to
better reflect their purpose.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Fix whitespace errors and arrange local variables for better
readability.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently the chip name buffer is allocated on the stack and the
address of the buffer is passed to the gpio framework. It's invalid
after probe() returns, so the sysfs label attribute displays garbage.

Use devm_kasprintf() for each string instead.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This variable is not used outside this module. Make it static.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This patch add basic structure of a virtual gpio device(gpio-mockup)
for testing gpio subsystem. The tester could manipulate such device
through userspace(sysfs or char device) and check the result from
debugfs.

Currently, it support one or more gpiochip(determined by module
parameters with base,ngpio pair). One could test the overlap of
different gpiochip and test the direction and/or output values of
these chips.
Signed-off-by: NKamlakant Patel <kamlakant.patel@broadcom.com>
Signed-off-by: NBamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>