fwnode_property_get_reference_args() now returns -ENOTCONN when called
on a software node referencing another software node which has not yet
been registered as a firmware node. It makes sense to defer probe in this
situation as the node will most likely be registered later on and we'll
be able to resolve the reference eventually. Change the behavior of
swnode_find_gpio() to return -EPROBE_DEFER if the software node reference
resolution returns -ENOTCONN.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260407-swnode-unreg-retcode-v4-2-1b2f0725eb9c@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Using the remote firmware node for software node lookup is the right
thing to do. The GPIO controller we want to resolve should have the
software node we scooped out of the reference attached to it. However,
there are existing users who abuse the software node API by creating
dummy swnodes whose name is set to the expected label string of the GPIO
controller whose pins they want to control and use them in their local
swnode references as GPIO properties.
This used to work when we compared the software node's name to the
chip's label. When we switched to using a real fwnode lookup, these
users broke down because the firmware nodes in question were never
attached to the controllers they were looking for.
Restore the label matching as a fallback to fix the broken users but add
a big FIXME urging for a better solution.
Cc: stable@vger.kernel.org # v6.18, v6.19
Fixes: 216c120475 ("gpio: swnode: allow referencing GPIO chips by firmware nodes")
Link: https://lore.kernel.org/all/aYkdKfP5fg6iywgr@jekhomev/
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Link: https://patch.msgid.link/20260211085313.16792-1-bartosz.golaszewski@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
When doing a software node lookup, we require both the fwnode that
references a GPIO chip as well as the node associated with that chip to
be software nodes. However, we now allow referencing generic firmware
nodes from software nodes in driver core so we should allow the same in
GPIO core. Make the software node name check optional and dependent on
whether the referenced firmware node is a software node. If it's not,
just continue with the lookup.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Looking up a GPIO controller by label that is the name of the software
node is wonky at best - the GPIO controller driver is free to set
a different label than the name of its firmware node. We're already being
passed a firmware node handle attached to the GPIO device to
swnode_get_gpio_device() so use it instead for a more precise lookup.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Fixes: e7f9ff5dc9 ("gpiolib: add support for software nodes")
Link: https://lore.kernel.org/r/20251103-reset-gpios-swnodes-v4-4-6461800b6775@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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>
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>
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>
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>
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>
