OpenCloudOS-Kernel/drivers/gpio/gpiolib-swnode.h

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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>
2022-11-12 06:19:08 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef GPIOLIB_SWNODE_H
#define GPIOLIB_SWNODE_H
struct fwnode_handle;
struct gpio_desc;
struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode,
const char *con_id, unsigned int idx,
unsigned long *flags);
int swnode_gpio_count(const struct fwnode_handle *fwnode, const char *con_id);
#endif /* GPIOLIB_SWNODE_H */