Commit Graph

9 Commits

Author SHA1 Message Date
Suraj Sonawane
a14968aea6 gpio: fix uninit-value in swnode_find_gpio
Fix an issue detected by the Smatch tool:

drivers/gpio/gpiolib-swnode.c:78 swnode_find_gpio() error:
uninitialized symbol 'ret'.

The issue occurs because the 'ret' variable may be used without
initialization if the for_each_gpio_property_name loop does not run.
This could lead to returning an undefined value, causing unpredictable
behavior.

Initialize 'ret' to 0 before the loop to ensure the function
returns an error code if no properties are parsed, maintaining proper
error handling.

Fixes: 9e4c6c1ad ("Merge tag 'io_uring-6.12-20241011' of git://git.kernel.dk/linux")
Signed-off-by: Suraj Sonawane <surajsonawane0215@gmail.com>
Link: https://lore.kernel.org/r/20241026090642.28633-1-surajsonawane0215@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-10-31 13:39:25 +01:00
Andy Shevchenko
94bd9ce160 gpiolib: Update the kernel documentation - add Return sections
$ scripts/kernel-doc -v -none -Wall drivers/gpio/gpiolib* 2>&1 | grep -w warning | wc -l
67

Fix these by adding Return sections. While at it, make sure all of
Return sections use the same style.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240828164449.2777666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-09-02 12:27:36 +02:00
Andy Shevchenko
a975a64692 gpiolib: swnode: Make use of for_each_gpio_property_name()
For the sake of unification and easier maintenance replace
swnode_format_propname() call with for_each_gpio_property_name()
for-loop.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240819142945.327808-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-08-20 10:22:38 +02:00
Andy Shevchenko
7fd6809888 gpiolib: swnode: Introduce swnode_gpio_get_reference() helper
Instead of the spreading simlar code over the file, introduce a helper.
It also enforces the nargs validation for all GPIO software node APIs.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240819142945.327808-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-08-20 10:22:38 +02:00
Andy Shevchenko
e42fce0ff9 gpiolib: swnode: Unify return code variable name
In one case 'ret' is used in the other 'error'. Make the latter
use the former, i.e. 'ret'.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240819142945.327808-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-08-20 10:22:38 +02:00
Charles Keepax
9d50f95bc0
gpio: swnode: Add ability to specify native chip selects for SPI
SPI devices can specify a cs-gpios property to enumerate their
chip selects. Under device tree, a zero entry in this property can
be used to specify that a particular chip select is using the SPI
controllers native chip select, for example:

        cs-gpios = <&gpio1 0 0>, <0>;

Here, the second chip select is native. However, when using swnodes
there is currently no way to specify a native chip select. The
proposal here is to register a swnode_gpio_undefined software node,
that can be specified to allow the indication of a native chip
select. For example:

static const struct software_node_ref_args device_cs_refs[] = {
	{
		.node  = &device_gpiochip_swnode,
		.nargs = 2,
		.args  = { 0, GPIO_ACTIVE_LOW },
	},
	{
		.node  = &swnode_gpio_undefined,
		.nargs = 0,
	},
};

Register the swnode as the gpiolib is initialised and check in
swnode_get_gpio_device() if the returned node matches
swnode_gpio_undefined and return -ENOENT, which matches the
behaviour of the device tree system when it encounters a 0 phandle.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20240416100904.3738093-2-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2024-04-16 20:00:27 +09:00
Bartosz Golaszewski
b7b56e64a3 gpio: swnode: replace gpiochip_find() with gpio_device_find_by_label()
We're porting all users of gpiochip_find() to using gpio_device_find().
Update the swnode GPIO code.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2023-10-04 13:36:23 +02:00
Andy Shevchenko
380c7ba392 gpiolib: Clean up headers
There is a few things done:
- include only the headers we are direct user of
- when pointer is in use, provide a forward declaration
- add missing headers
- group generic headers and subsystem headers
- sort each group alphabetically

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-03-06 12:33:02 +02:00
Dmitry Torokhov
e7f9ff5dc9 gpiolib: add support for software nodes
Now that static device properties understand notion of child nodes and
references, let's teach gpiolib to handle them:

- GPIOs are represented as a references to software nodes representing
  gpiochip
- references must have 2 arguments - GPIO number within the chip and
  GPIO flags (GPIO_ACTIVE_LOW/GPIO_ACTIVE_HIGH, etc)
- a new PROPERTY_ENTRY_GPIO() macro is supplied to ensure the above
- name of the software node representing gpiochip must match label of
  the gpiochip, as we use it to locate gpiochip structure at runtime

The following illustrates use of software nodes to describe a "System"
button that is currently specified via use of gpio_keys_platform_data
in arch/mips/alchemy/board-mtx1.c. It follows bindings specified in
Documentation/devicetree/bindings/input/gpio-keys.yaml.

static const struct software_node mxt1_gpiochip2_node = {
	.name = "alchemy-gpio2",
};

static const struct property_entry mtx1_gpio_button_props[] = {
	PROPERTY_ENTRY_U32("linux,code", BTN_0),
	PROPERTY_ENTRY_STRING("label", "System button"),
	PROPERTY_ENTRY_GPIO("gpios", &mxt1_gpiochip2_node, 7, GPIO_ACTIVE_LOW),
	{ }
};

Similarly, arch/arm/mach-tegra/board-paz00.c can be converted to:

static const struct software_node tegra_gpiochip_node = {
	.name = "tegra-gpio",
};

static struct property_entry wifi_rfkill_prop[] __initdata = {
	PROPERTY_ENTRY_STRING("name", "wifi_rfkill"),
	PROPERTY_ENTRY_STRING("type", "wlan"),
	PROPERTY_ENTRY_GPIO("reset-gpios",
			    &tegra_gpiochip_node, 25, GPIO_ACTIVE_HIGH);
	PROPERTY_ENTRY_GPIO("shutdown-gpios",
			    &tegra_gpiochip_node, 85, GPIO_ACTIVE_HIGH);
	{ },
};

static struct platform_device wifi_rfkill_device = {
	.name	= "rfkill_gpio",
	.id	= -1,
};

...

	software_node_register(&tegra_gpiochip_node);
	device_create_managed_software_node(&wifi_rfkill_device.dev,
					    wifi_rfkill_prop, NULL);

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2022-11-15 11:21:43 +01:00