gpio_keys.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <acpi/acpi_device.h>
#include <acpi/acpigen.h>
#include <device/device.h>
#include <device/path.h>
#include <string.h>
 
#include "chip.h"
 
static struct acpi_dp *gpio_keys_add_child_node(
                        struct drivers_generic_gpio_keys_config *config,
                        const char *parent_path)
{
        struct key_info *key = &config->key;
        struct acpi_dp *dsd;
 
        if (!key->dev_name || !key->linux_code)
                return NULL;
 
        dsd = acpi_dp_new_table(config->key.dev_name);
 
        acpi_dp_add_integer(dsd, "linux,code", key->linux_code);
        if (key->linux_input_type)
                acpi_dp_add_integer(dsd, "linux,input-type",
                                    key->linux_input_type);
        if (key->label)
                acpi_dp_add_string(dsd, "label", key->label);
 
        if (key->wakeup_route == WAKEUP_ROUTE_SCI)
                acpigen_write_PRW(key->wake_gpe, 3);
 
        if (key->wakeup_route != WAKEUP_ROUTE_DISABLED) {
                acpi_dp_add_integer(dsd, "wakeup-source", 1);
                acpi_dp_add_integer(dsd, "wakeup-event-action",
                                        key->wakeup_event_action);
        }
 
        if (key->can_be_disabled)
                acpi_dp_add_integer(dsd, "linux,can-disable",
                                    key->can_be_disabled);
        if (key->debounce_interval)
                acpi_dp_add_integer(dsd, "debounce-interval",
                                    key->debounce_interval);
        acpi_dp_add_gpio(dsd, "gpios", parent_path, 0, 0,
                         config->gpio.active_low);
 
        return dsd;
}
 
static void gpio_keys_fill_ssdt_generator(const struct device *dev)
{
        struct drivers_generic_gpio_keys_config *config = dev->chip_info;
        const char *scope = acpi_device_scope(dev);
        const char *path = acpi_device_path(dev);
        struct acpi_dp *dsd, *child;
        const char *drv_string = config->is_polled ? "gpio-keys-polled"
                                : "gpio-keys";
 
        if (!scope || !path || !config->gpio.pin_count)
                return;
 
        /* Device */
        acpigen_write_scope(scope);
        acpigen_write_device(acpi_device_name(dev));
 
        /* _HID is set to PRP0001 */
        acpigen_write_name_string("_HID", ACPI_DT_NAMESPACE_HID);
 
        /* Resources - _CRS */
        acpigen_write_name("_CRS");
        acpigen_write_resourcetemplate_header();
        acpi_device_write_gpio(&config->gpio);
        acpigen_write_resourcetemplate_footer();
 
        /* DSD */
        dsd = acpi_dp_new_table("_DSD");
        acpi_dp_add_string(dsd, "compatible", drv_string);
        if (config->label)
                acpi_dp_add_string(dsd, "label", config->label);
        if (config->is_polled)
                acpi_dp_add_integer(dsd, "poll-interval",
                                        config->poll_interval);
        /* Child device defining key */
        child = gpio_keys_add_child_node(config, path);
        if (child)
                acpi_dp_add_child(dsd, "button-0", child);
        acpi_dp_write(dsd);
 
        acpigen_pop_len(); /* Device */
        acpigen_pop_len(); /* Scope */
}
 
static const char *gpio_keys_acpi_name(const struct device *dev)
{
        struct drivers_generic_gpio_keys_config *config = dev->chip_info;
        static char name[5];
 
        if (config->name)
                return config->name;
 
        snprintf(name, sizeof(name), "K%03.3X", config->gpio.pins[0]);
        name[4] = '\0';
 
        return name;
}
 
static struct device_operations gpio_keys_ops = {
        .read_resources         = noop_read_resources,
        .set_resources          = noop_set_resources,
        .acpi_name              = gpio_keys_acpi_name,
        .acpi_fill_ssdt         = gpio_keys_fill_ssdt_generator,
};
 
static void gpio_keys_enable(struct device *dev)
{
        dev->ops = &gpio_keys_ops;
}
 
struct chip_operations drivers_generic_gpio_keys_ops = {
        CHIP_NAME("GPIO Keys")
        .enable_dev = gpio_keys_enable
};