// SPDX-License-Identifier: MIT
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <linux/mxm-wmi.h>
#include <linux/vga_switcheroo.h>
#include <drm/drm_edid.h>
#include <acpi/video.h>

#include "nouveau_drv.h"
#include "nouveau_acpi.h"

#define NOUVEAU_DSM_LED 0x02
#define NOUVEAU_DSM_LED_STATE 0x00
#define NOUVEAU_DSM_LED_OFF 0x10
#define NOUVEAU_DSM_LED_STAMINA 0x11
#define NOUVEAU_DSM_LED_SPEED 0x12

#define NOUVEAU_DSM_POWER 0x03
#define NOUVEAU_DSM_POWER_STATE 0x00
#define NOUVEAU_DSM_POWER_SPEED 0x01
#define NOUVEAU_DSM_POWER_STAMINA 0x02

#define NOUVEAU_DSM_OPTIMUS_CAPS 0x1A
#define NOUVEAU_DSM_OPTIMUS_FLAGS 0x1B

#define NOUVEAU_DSM_OPTIMUS_POWERDOWN_PS3 (3 << 24)
#define NOUVEAU_DSM_OPTIMUS_NO_POWERDOWN_PS3 (2 << 24)
#define NOUVEAU_DSM_OPTIMUS_FLAGS_CHANGED (1)

#define NOUVEAU_DSM_OPTIMUS_SET_POWERDOWN (NOUVEAU_DSM_OPTIMUS_POWERDOWN_PS3 | NOUVEAU_DSM_OPTIMUS_FLAGS_CHANGED)

/* result of the optimus caps function */
#define OPTIMUS_ENABLED (1 << 0)
#define OPTIMUS_STATUS_MASK (3 << 3)
#define OPTIMUS_STATUS_OFF  (0 << 3)
#define OPTIMUS_STATUS_ON_ENABLED  (1 << 3)
#define OPTIMUS_STATUS_PWR_STABLE  (3 << 3)
#define OPTIMUS_DISPLAY_HOTPLUG (1 << 6)
#define OPTIMUS_CAPS_MASK (7 << 24)
#define OPTIMUS_DYNAMIC_PWR_CAP (1 << 24)

#define OPTIMUS_AUDIO_CAPS_MASK (3 << 27)
#define OPTIMUS_HDA_CODEC_MASK (2 << 27) /* hda bios control */

static struct nouveau_dsm_priv {
        bool dsm_detected;
        bool optimus_detected;
        bool optimus_flags_detected;
        bool optimus_skip_dsm;
        acpi_handle dhandle;
} nouveau_dsm_priv;

bool nouveau_is_optimus(void) {
        return nouveau_dsm_priv.optimus_detected;
}

bool nouveau_is_v1_dsm(void) {
        return nouveau_dsm_priv.dsm_detected;
}

#ifdef CONFIG_VGA_SWITCHEROO
static const guid_t nouveau_dsm_muid =
        GUID_INIT(0x9D95A0A0, 0x0060, 0x4D48,
                  0xB3, 0x4D, 0x7E, 0x5F, 0xEA, 0x12, 0x9F, 0xD4);

static const guid_t nouveau_op_dsm_muid =
        GUID_INIT(0xA486D8F8, 0x0BDA, 0x471B,
                  0xA7, 0x2B, 0x60, 0x42, 0xA6, 0xB5, 0xBE, 0xE0);

static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *result)
{
        int i;
        union acpi_object *obj;
        char args_buff[4];
        union acpi_object argv4 = {
                .buffer.type = ACPI_TYPE_BUFFER,
                .buffer.length = 4,
                .buffer.pointer = args_buff
        };

        /* ACPI is little endian, AABBCCDD becomes {DD,CC,BB,AA} */
        for (i = 0; i < 4; i++)
                args_buff[i] = (arg >> i * 8) & 0xFF;

        *result = 0;
        obj = acpi_evaluate_dsm_typed(handle, &nouveau_op_dsm_muid, 0x00000100,
                                      func, &argv4, ACPI_TYPE_BUFFER);
        if (!obj) {
                acpi_handle_info(handle, "failed to evaluate _DSM\n");
                return AE_ERROR;
        } else {
                if (obj->buffer.length == 4) {
                        *result |= obj->buffer.pointer[0];
                        *result |= (obj->buffer.pointer[1] << 8);
                        *result |= (obj->buffer.pointer[2] << 16);
                        *result |= (obj->buffer.pointer[3] << 24);
                }
                ACPI_FREE(obj);
        }

        return 0;
}

/*
 * On some platforms, _DSM(nouveau_op_dsm_muid, func0) has special
 * requirements on the fourth parameter, so a private implementation
 * instead of using acpi_check_dsm().
 */
static int nouveau_dsm_get_optimus_functions(acpi_handle handle)
{
        int result;

        /*
         * Function 0 returns a Buffer containing available functions.
         * The args parameter is ignored for function 0, so just put 0 in it
         */
        if (nouveau_optimus_dsm(handle, 0, 0, &result))
                return 0;

        /*
         * ACPI Spec v4 9.14.1: if bit 0 is zero, no function is supported.
         * If the n-th bit is enabled, function n is supported
         */
        if (result & 1 && result & (1 << NOUVEAU_DSM_OPTIMUS_CAPS))
                return result;
        return 0;
}

static int nouveau_dsm(acpi_handle handle, int func, int arg)
{
        int ret = 0;
        union acpi_object *obj;
        union acpi_object argv4 = {
                .integer.type = ACPI_TYPE_INTEGER,
                .integer.value = arg,
        };

        obj = acpi_evaluate_dsm_typed(handle, &nouveau_dsm_muid, 0x00000102,
                                      func, &argv4, ACPI_TYPE_INTEGER);
        if (!obj) {
                acpi_handle_info(handle, "failed to evaluate _DSM\n");
                return AE_ERROR;
        } else {
                if (obj->integer.value == 0x80000002)
                        ret = -ENODEV;
                ACPI_FREE(obj);
        }

        return ret;
}

static int nouveau_dsm_switch_mux(acpi_handle handle, int mux_id)
{
        mxm_wmi_call_mxmx(mux_id == NOUVEAU_DSM_LED_STAMINA ? MXM_MXDS_ADAPTER_IGD : MXM_MXDS_ADAPTER_0);
        mxm_wmi_call_mxds(mux_id == NOUVEAU_DSM_LED_STAMINA ? MXM_MXDS_ADAPTER_IGD : MXM_MXDS_ADAPTER_0);
        return nouveau_dsm(handle, NOUVEAU_DSM_LED, mux_id);
}

static int nouveau_dsm_set_discrete_state(acpi_handle handle, enum vga_switcheroo_state state)
{
        int arg;
        if (state == VGA_SWITCHEROO_ON)
                arg = NOUVEAU_DSM_POWER_SPEED;
        else
                arg = NOUVEAU_DSM_POWER_STAMINA;
        nouveau_dsm(handle, NOUVEAU_DSM_POWER, arg);
        return 0;
}

static int nouveau_dsm_switchto(enum vga_switcheroo_client_id id)
{
        if (!nouveau_dsm_priv.dsm_detected)
                return 0;
        if (id == VGA_SWITCHEROO_IGD)
                return nouveau_dsm_switch_mux(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_LED_STAMINA);
        else
                return nouveau_dsm_switch_mux(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_LED_SPEED);
}

static int nouveau_dsm_power_state(enum vga_switcheroo_client_id id,
                                   enum vga_switcheroo_state state)
{
        if (id == VGA_SWITCHEROO_IGD)
                return 0;

        /* Optimus laptops have the card already disabled in
         * nouveau_switcheroo_set_state */
        if (!nouveau_dsm_priv.dsm_detected)
                return 0;

        return nouveau_dsm_set_discrete_state(nouveau_dsm_priv.dhandle, state);
}

static enum vga_switcheroo_client_id nouveau_dsm_get_client_id(struct pci_dev *pdev)
{
        /* easy option one - intel vendor ID means Integrated */
        if (pdev->vendor == PCI_VENDOR_ID_INTEL)
                return VGA_SWITCHEROO_IGD;

        /* is this device on Bus 0? - this may need improving */
        if (pdev->bus->number == 0)
                return VGA_SWITCHEROO_IGD;

        return VGA_SWITCHEROO_DIS;
}

static const struct vga_switcheroo_handler nouveau_dsm_handler = {
        .switchto = nouveau_dsm_switchto,
        .power_state = nouveau_dsm_power_state,
        .get_client_id = nouveau_dsm_get_client_id,
};

static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out,
                                  bool *has_mux, bool *has_opt,
                                  bool *has_opt_flags, bool *has_pr3)
{
        acpi_handle dhandle;
        bool supports_mux;
        int optimus_funcs;
        struct pci_dev *parent_pdev;

        if (pdev->vendor != PCI_VENDOR_ID_NVIDIA)
                return;

        *has_pr3 = false;
        parent_pdev = pci_upstream_bridge(pdev);
        if (parent_pdev) {
                if (parent_pdev->bridge_d3)
                        *has_pr3 = pci_pr3_present(parent_pdev);
                else
                        pci_d3cold_disable(pdev);
        }

        dhandle = ACPI_HANDLE(&pdev->dev);
        if (!dhandle)
                return;

        if (!acpi_has_method(dhandle, "_DSM"))
                return;

        supports_mux = acpi_check_dsm(dhandle, &nouveau_dsm_muid, 0x00000102,
                                      1 << NOUVEAU_DSM_POWER);
        optimus_funcs = nouveau_dsm_get_optimus_functions(dhandle);

        /* Does not look like a Nvidia device. */
        if (!supports_mux && !optimus_funcs)
                return;

        *dhandle_out = dhandle;
        *has_mux = supports_mux;
        *has_opt = !!optimus_funcs;
        *has_opt_flags = optimus_funcs & (1 << NOUVEAU_DSM_OPTIMUS_FLAGS);

        if (optimus_funcs) {
                uint32_t result;
                nouveau_optimus_dsm(dhandle, NOUVEAU_DSM_OPTIMUS_CAPS, 0,
                                    &result);
                dev_info(&pdev->dev, "optimus capabilities: %s, status %s%s\n",
                         (result & OPTIMUS_ENABLED) ? "enabled" : "disabled",
                         (result & OPTIMUS_DYNAMIC_PWR_CAP) ? "dynamic power, " : "",
                         (result & OPTIMUS_HDA_CODEC_MASK) ? "hda bios codec supported" : "");
        }
}

static bool nouveau_dsm_detect(void)
{
        char acpi_method_name[255] = { 0 };
        struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
        struct pci_dev *pdev = NULL;
        acpi_handle dhandle = NULL;
        bool has_mux = false;
        bool has_optimus = false;
        bool has_optimus_flags = false;
        bool has_power_resources = false;
        int vga_count = 0;
        bool guid_valid;
        bool ret = false;

        /* lookup the MXM GUID */
        guid_valid = mxm_wmi_supported();

        if (guid_valid)
                printk("MXM: GUID detected in BIOS\n");

        /* now do DSM detection */
        while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
                if ((pdev->class != PCI_CLASS_DISPLAY_VGA << 8) &&
                    (pdev->class != PCI_CLASS_DISPLAY_3D << 8))
                        continue;

                vga_count++;

                nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus,
                                      &has_optimus_flags, &has_power_resources);
        }

        /* find the optimus DSM or the old v1 DSM */
        if (has_optimus) {
                nouveau_dsm_priv.dhandle = dhandle;
                acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
                        &buffer);
                pr_info("VGA switcheroo: detected Optimus DSM method %s handle\n",
                        acpi_method_name);
                if (has_power_resources)
                        pr_info("nouveau: detected PR support, will not use DSM\n");
                nouveau_dsm_priv.optimus_detected = true;
                nouveau_dsm_priv.optimus_flags_detected = has_optimus_flags;
                nouveau_dsm_priv.optimus_skip_dsm = has_power_resources;
                ret = true;
        } else if (vga_count == 2 && has_mux && guid_valid) {
                nouveau_dsm_priv.dhandle = dhandle;
                acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
                        &buffer);
                pr_info("VGA switcheroo: detected DSM switching method %s handle\n",
                        acpi_method_name);
                nouveau_dsm_priv.dsm_detected = true;
                ret = true;
        }


        return ret;
}

void nouveau_register_dsm_handler(void)
{
        bool r;

        r = nouveau_dsm_detect();
        if (!r)
                return;

        vga_switcheroo_register_handler(&nouveau_dsm_handler, 0);
}

/* Must be called for Optimus models before the card can be turned off */
void nouveau_switcheroo_optimus_dsm(void)
{
        u32 result = 0;
        if (!nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.optimus_skip_dsm)
                return;

        if (nouveau_dsm_priv.optimus_flags_detected)
                nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_FLAGS,
                                    0x3, &result);

        nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_CAPS,
                NOUVEAU_DSM_OPTIMUS_SET_POWERDOWN, &result);

}

void nouveau_unregister_dsm_handler(void)
{
        if (nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.dsm_detected)
                vga_switcheroo_unregister_handler();
}
#else
void nouveau_register_dsm_handler(void) {}
void nouveau_unregister_dsm_handler(void) {}
void nouveau_switcheroo_optimus_dsm(void) {}
#endif

void *
nouveau_acpi_edid(struct drm_device *dev, struct drm_connector *connector)
{
        struct acpi_device *acpidev;
        int type, ret;
        void *edid;

        switch (connector->connector_type) {
        case DRM_MODE_CONNECTOR_LVDS:
        case DRM_MODE_CONNECTOR_eDP:
                type = ACPI_VIDEO_DISPLAY_LCD;
                break;
        default:
                return NULL;
        }

        acpidev = ACPI_COMPANION(dev->dev);
        if (!acpidev)
                return NULL;

        ret = acpi_video_get_edid(acpidev, type, -1, &edid);
        if (ret < 0)
                return NULL;

        return edid;
}

bool nouveau_acpi_video_backlight_use_native(void)
{
        return acpi_video_backlight_use_native();
}

void nouveau_acpi_video_register_backlight(void)
{
        acpi_video_register_backlight();
}