// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * pnpacpi -- PnP ACPI driver
 *
 * Copyright (c) 2004 Matthieu Castet <castet.matthieu@free.fr>
 * Copyright (c) 2004 Li Shaohua <shaohua.li@intel.com>
 */

#include <linux/export.h>
#include <linux/acpi.h>
#include <linux/pnp.h>
#include <linux/slab.h>
#include <linux/mod_devicetable.h>

#include "../base.h"
#include "pnpacpi.h"

static int num;

/*
 * Compatible Device IDs
 */
#define TEST_HEX(c) \
        if (!(('0' <= (c) && (c) <= '9') || ('A' <= (c) && (c) <= 'F'))) \
                return 0
#define TEST_ALPHA(c) \
        if (!('A' <= (c) && (c) <= 'Z')) \
                return 0
static int __init ispnpidacpi(const char *id)
{
        TEST_ALPHA(id[0]);
        TEST_ALPHA(id[1]);
        TEST_ALPHA(id[2]);
        TEST_HEX(id[3]);
        TEST_HEX(id[4]);
        TEST_HEX(id[5]);
        TEST_HEX(id[6]);
        if (id[7] != '\0')
                return 0;
        return 1;
}

static int pnpacpi_get_resources(struct pnp_dev *dev)
{
        pnp_dbg(&dev->dev, "get resources\n");
        return pnpacpi_parse_allocated_resource(dev);
}

static int pnpacpi_set_resources(struct pnp_dev *dev)
{
        struct acpi_device *acpi_dev;
        acpi_handle handle;
        int ret = 0;

        pnp_dbg(&dev->dev, "set resources\n");

        acpi_dev = ACPI_COMPANION(&dev->dev);
        if (!acpi_dev) {
                dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__);
                return -ENODEV;
        }

        if (WARN_ON_ONCE(acpi_dev != dev->data))
                dev->data = acpi_dev;

        handle = acpi_dev->handle;
        if (acpi_has_method(handle, METHOD_NAME__SRS)) {
                struct acpi_buffer buffer;

                ret = pnpacpi_build_resource_template(dev, &buffer);
                if (ret)
                        return ret;

                ret = pnpacpi_encode_resources(dev, &buffer);
                if (!ret) {
                        acpi_status status;

                        status = acpi_set_current_resources(handle, &buffer);
                        if (ACPI_FAILURE(status))
                                ret = -EIO;
                }
                kfree(buffer.pointer);
        }
        if (!ret && acpi_device_power_manageable(acpi_dev))
                ret = acpi_device_set_power(acpi_dev, ACPI_STATE_D0);

        return ret;
}

static int pnpacpi_disable_resources(struct pnp_dev *dev)
{
        struct acpi_device *acpi_dev;
        acpi_status status;

        dev_dbg(&dev->dev, "disable resources\n");

        acpi_dev = ACPI_COMPANION(&dev->dev);
        if (!acpi_dev) {
                dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__);
                return 0;
        }

        /* acpi_unregister_gsi(pnp_irq(dev, 0)); */
        if (acpi_device_power_manageable(acpi_dev))
                acpi_device_set_power(acpi_dev, ACPI_STATE_D3_COLD);

        /* continue even if acpi_device_set_power() fails */
        status = acpi_evaluate_object(acpi_dev->handle, "_DIS", NULL, NULL);
        if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
                return -ENODEV;

        return 0;
}

#ifdef CONFIG_ACPI_SLEEP
static bool pnpacpi_can_wakeup(struct pnp_dev *dev)
{
        struct acpi_device *acpi_dev = ACPI_COMPANION(&dev->dev);

        if (!acpi_dev) {
                dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__);
                return false;
        }

        return acpi_bus_can_wakeup(acpi_dev->handle);
}

static int pnpacpi_suspend(struct pnp_dev *dev, pm_message_t state)
{
        struct acpi_device *acpi_dev = ACPI_COMPANION(&dev->dev);
        int error = 0;

        if (!acpi_dev) {
                dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__);
                return 0;
        }

        if (device_can_wakeup(&dev->dev)) {
                error = acpi_pm_set_device_wakeup(&dev->dev,
                                              device_may_wakeup(&dev->dev));
                if (error)
                        return error;
        }

        if (acpi_device_power_manageable(acpi_dev)) {
                int power_state = acpi_pm_device_sleep_state(&dev->dev, NULL,
                                                        ACPI_STATE_D3_COLD);
                if (power_state < 0)
                        power_state = (state.event == PM_EVENT_ON) ?
                                        ACPI_STATE_D0 : ACPI_STATE_D3_COLD;

                /*
                 * acpi_device_set_power() can fail (keyboard port can't be
                 * powered-down?), and in any case, our return value is ignored
                 * by pnp_bus_suspend().  Hence we don't revert the wakeup
                 * setting if the set_power fails.
                 */
                error = acpi_device_set_power(acpi_dev, power_state);
        }

        return error;
}

static int pnpacpi_resume(struct pnp_dev *dev)
{
        struct acpi_device *acpi_dev = ACPI_COMPANION(&dev->dev);
        int error = 0;

        if (!acpi_dev) {
                dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__);
                return -ENODEV;
        }

        if (device_may_wakeup(&dev->dev))
                acpi_pm_set_device_wakeup(&dev->dev, false);

        if (acpi_device_power_manageable(acpi_dev))
                error = acpi_device_set_power(acpi_dev, ACPI_STATE_D0);

        return error;
}
#endif

struct pnp_protocol pnpacpi_protocol = {
        .name    = "Plug and Play ACPI",
        .get     = pnpacpi_get_resources,
        .set     = pnpacpi_set_resources,
        .disable = pnpacpi_disable_resources,
#ifdef CONFIG_ACPI_SLEEP
        .can_wakeup = pnpacpi_can_wakeup,
        .suspend = pnpacpi_suspend,
        .resume = pnpacpi_resume,
#endif
};
EXPORT_SYMBOL(pnpacpi_protocol);

static const char *__init pnpacpi_get_id(struct acpi_device *device)
{
        struct acpi_hardware_id *id;

        list_for_each_entry(id, &device->pnp.ids, list) {
                if (ispnpidacpi(id->id))
                        return id->id;
        }

        return NULL;
}

static int __init pnpacpi_add_device(struct acpi_device *device)
{
        struct pnp_dev *dev;
        const char *pnpid;
        struct acpi_hardware_id *id;
        int error;

        /* Skip devices that are already bound */
        if (device->physical_node_count)
                return 0;

        /*
         * If a PnPacpi device is not present , the device
         * driver should not be loaded.
         */
        if (!acpi_has_method(device->handle, "_CRS"))
                return 0;

        pnpid = pnpacpi_get_id(device);
        if (!pnpid)
                return 0;

        if (!device->status.present)
                return 0;

        dev = pnp_alloc_dev(&pnpacpi_protocol, num, pnpid);
        if (!dev)
                return -ENOMEM;

        ACPI_COMPANION_SET(&dev->dev, device);
        dev->data = device;
        /* .enabled means the device can decode the resources */
        dev->active = device->status.enabled;
        if (acpi_has_method(device->handle, "_SRS"))
                dev->capabilities |= PNP_CONFIGURABLE;
        dev->capabilities |= PNP_READ;
        if (device->flags.dynamic_status && (dev->capabilities & PNP_CONFIGURABLE))
                dev->capabilities |= PNP_WRITE;
        if (device->flags.removable)
                dev->capabilities |= PNP_REMOVABLE;
        if (acpi_has_method(device->handle, "_DIS"))
                dev->capabilities |= PNP_DISABLE;

        if (strlen(acpi_device_name(device)))
                strscpy(dev->name, acpi_device_name(device), sizeof(dev->name));
        else
                strscpy(dev->name, acpi_device_bid(device), sizeof(dev->name));

        if (dev->active)
                pnpacpi_parse_allocated_resource(dev);

        if (dev->capabilities & PNP_CONFIGURABLE)
                pnpacpi_parse_resource_option_data(dev);

        list_for_each_entry(id, &device->pnp.ids, list) {
                if (!strcmp(id->id, pnpid))
                        continue;
                if (!ispnpidacpi(id->id))
                        continue;
                pnp_add_id(dev, id->id);
        }

        /* clear out the damaged flags */
        if (!dev->active)
                pnp_init_resources(dev);

        error = pnp_add_device(dev);
        if (error) {
                put_device(&dev->dev);
                return error;
        }

        num++;

        return 0;
}

static acpi_status __init pnpacpi_add_device_handler(acpi_handle handle,
                                                     u32 lvl, void *context,
                                                     void **rv)
{
        struct acpi_device *device = acpi_fetch_acpi_dev(handle);

        if (!device)
                return AE_CTRL_DEPTH;
        if (acpi_is_pnp_device(device))
                pnpacpi_add_device(device);
        return AE_OK;
}

int pnpacpi_disabled __initdata;
static int __init pnpacpi_init(void)
{
        if (acpi_disabled || pnpacpi_disabled) {
                printk(KERN_INFO "pnp: PnP ACPI: disabled\n");
                return 0;
        }
        printk(KERN_INFO "pnp: PnP ACPI init\n");
        pnp_register_protocol(&pnpacpi_protocol);
        acpi_get_devices(NULL, pnpacpi_add_device_handler, NULL, NULL);
        printk(KERN_INFO "pnp: PnP ACPI: found %d devices\n", num);
        pnp_platform_devices = 1;
        return 0;
}

fs_initcall(pnpacpi_init);

static int __init pnpacpi_setup(char *str)
{
        if (str == NULL)
                return 1;
        if (!strncmp(str, "off", 3))
                pnpacpi_disabled = 1;
        return 1;
}

__setup("pnpacpi=", pnpacpi_setup);