[PATCH v3 0/6] Add support for software nodes to gpiolib

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

This series attempts to add support for software nodes to gpiolib, using
software node references. This allows us to convert more drivers to the
generic device properties and drop support for custom platform data.

To describe a GPIO via software nodes we can create the following data
items:

/* Node representing the GPIO controller/GPIO bank */
static const struct software_node gpio_bank_b_node = {
        .name = "B",
};

/*
 * Properties that will be assigned to a software node assigned to
 * the device that used platform data.
 */
static const struct property_entry simone_key_enter_props[] = {
        PROPERTY_ENTRY_U32("linux,code", KEY_ENTER),
        PROPERTY_ENTRY_STRING("label", "enter"),
        PROPERTY_ENTRY_REF("gpios", &gpio_bank_b_node, 123, GPIO_ACTIVE_LOW),
        { }
};

The code in gpiolib handling software nodes uses the name in the
software node representing GPIO controller to locate the actual instance
of GPIO controller.

To: Linus Walleij <linus.walleij@linaro.org>
To: Bartosz Golaszewski <brgl@bgdev.pl>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-acpi@vger.kernel.org

---
Changes in v3:
- Addressed more Andy's comments
- Link to v2: https://lore.kernel.org/r/20221031-gpiolib-swnode-v2-0-81f55af5fa0e@gmail.com

Changes in v2:
- reworked the series to be independent of other in-flight patches.
  That meant keeping devm_gpiod_get_from_of_node() for now.
- removed handling of secondary nodes, it deserves a separate patch
  series
- fixed refcounting when handling swnodes (Andy)
- added include/linux/gpio/property.h with PROPERTY_ENTRY_GPIO (Andy)
- addressed most of the rest of Andy's comments
- collected reviewed-by and acked-by
- Link to v1: https://lore.kernel.org/r/20221031-gpiolib-swnode-v1-0-a0ab48d229c7@gmail.com

---
Dmitry Torokhov (6):
      gpiolib: of: change of_find_gpio() to accept device node
      gpiolib: acpi: change acpi_find_gpio() to accept firmware node
      gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes
      gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers
      gpiolib: consolidate GPIO lookups
      gpiolib: add support for software nodes

 drivers/gpio/Makefile         |   1 +
 drivers/gpio/gpiolib-acpi.c   | 132 +++++++++++++++-----------
 drivers/gpio/gpiolib-acpi.h   |  54 +----------
 drivers/gpio/gpiolib-of.c     |   7 +-
 drivers/gpio/gpiolib-of.h     |   4 +-
 drivers/gpio/gpiolib-swnode.c | 123 +++++++++++++++++++++++++
 drivers/gpio/gpiolib-swnode.h |  14 +++
 drivers/gpio/gpiolib.c        | 209 ++++++++++++++++--------------------------
 include/linux/gpio/property.h |  11 +++
 9 files changed, 315 insertions(+), 240 deletions(-)
---
base-commit: b6fc3fddade7a194bd141a49f2689e50f796ef46
change-id: 20221031-gpiolib-swnode-948203f49b23

-- 
Dmitry