/*
 * Intel ACPI functions
 *
 * _DSM related code stolen from nouveau_acpi.c.
 */
#include <linux/pci.h>
#include <linux/acpi.h>
#include <drm/drmP.h>
#include "i915_drv.h"

#define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
#define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */

#if 0

static const guid_t intel_dsm_guid =
        GUID_INIT(0x7ed873d3, 0xc2d0, 0x4e4f,
                  0xa8, 0x54, 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c);

static char *intel_dsm_port_name(u8 id)
{
        switch (id) {
        case 0:
                return "Reserved";
        case 1:
                return "Analog VGA";
        case 2:
                return "LVDS";
        case 3:
                return "Reserved";
        case 4:
                return "HDMI/DVI_B";
        case 5:
                return "HDMI/DVI_C";
        case 6:
                return "HDMI/DVI_D";
        case 7:
                return "DisplayPort_A";
        case 8:
                return "DisplayPort_B";
        case 9:
                return "DisplayPort_C";
        case 0xa:
                return "DisplayPort_D";
        case 0xb:
        case 0xc:
        case 0xd:
                return "Reserved";
        case 0xe:
                return "WiDi";
        default:
                return "bad type";
        }
}

static char *intel_dsm_mux_type(u8 type)
{
        switch (type) {
        case 0:
                return "unknown";
        case 1:
                return "No MUX, iGPU only";
        case 2:
                return "No MUX, dGPU only";
        case 3:
                return "MUXed between iGPU and dGPU";
        default:
                return "bad type";
        }
}

static void intel_dsm_platform_mux_info(acpi_handle dhandle)
{
        int i;
        union acpi_object *pkg, *connector_count;

        pkg = acpi_evaluate_dsm_typed(dhandle, &intel_dsm_guid,
                        INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
                        NULL, ACPI_TYPE_PACKAGE);
        if (!pkg) {
                DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
                return;
        }

        connector_count = &pkg->package.elements[0];
        DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
                  (unsigned long long)connector_count->integer.value);
        for (i = 1; i < pkg->package.count; i++) {
                union acpi_object *obj = &pkg->package.elements[i];
                union acpi_object *connector_id = &obj->package.elements[0];
                union acpi_object *info = &obj->package.elements[1];
                DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
                          (unsigned long long)connector_id->integer.value);
                DRM_DEBUG_DRIVER("  port id: %s\n",
                       intel_dsm_port_name(info->buffer.pointer[0]));
                DRM_DEBUG_DRIVER("  display mux info: %s\n",
                       intel_dsm_mux_type(info->buffer.pointer[1]));
                DRM_DEBUG_DRIVER("  aux/dc mux info: %s\n",
                       intel_dsm_mux_type(info->buffer.pointer[2]));
                DRM_DEBUG_DRIVER("  hpd mux info: %s\n",
                       intel_dsm_mux_type(info->buffer.pointer[3]));
        }

        ACPI_FREE(pkg);
}

static acpi_handle intel_dsm_pci_probe(struct pci_dev *pdev)
{
        acpi_handle dhandle;

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

        if (!acpi_check_dsm(dhandle, &intel_dsm_guid, INTEL_DSM_REVISION_ID,
                            1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
                DRM_DEBUG_KMS("no _DSM method for intel device\n");
                return NULL;
        }

        intel_dsm_platform_mux_info(dhandle);

        return dhandle;
}

static bool intel_dsm_detect(void)
{
        acpi_handle dhandle = NULL;
        char acpi_method_name[255] = { 0 };
        struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
        struct pci_dev *pdev = NULL;
        int vga_count = 0;

        while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
                vga_count++;
                dhandle = intel_dsm_pci_probe(pdev) ?: dhandle;
        }

        if (vga_count == 2 && dhandle) {
                acpi_get_name(dhandle, ACPI_FULL_PATHNAME, &buffer);
                DRM_DEBUG_DRIVER("vga_switcheroo: detected DSM switching method %s handle\n",
                                 acpi_method_name);
                return true;
        }

        return false;
}

void intel_register_dsm_handler(void)
{
        if (!intel_dsm_detect())
                return;
}
#endif

void intel_unregister_dsm_handler(void)
{
}