nouveau_acpi.c

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#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>
#include <acpi/video.h>
#include <acpi/acpi.h>
#include <linux/mxm-wmi.h>

#include <linux/vga_switcheroo.h>

#include <drm/drm_edid.h>

#include "nouveau_drm.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_FN 0x1A
#define NOUVEAU_DSM_OPTIMUS_ARGS 0x03000001

static struct nouveau_dsm_priv {
    bool dsm_detected;
    bool optimus_detected;
    acpi_handle dhandle;
    acpi_handle rom_handle;
} nouveau_dsm_priv;

#define NOUVEAU_DSM_HAS_MUX 0x1
#define NOUVEAU_DSM_HAS_OPT 0x2

static const char nouveau_dsm_muid[] = {
    0xA0, 0xA0, 0x95, 0x9D, 0x60, 0x00, 0x48, 0x4D,
    0xB3, 0x4D, 0x7E, 0x5F, 0xEA, 0x12, 0x9F, 0xD4,
};

static const char nouveau_op_dsm_muid[] = {
    0xF8, 0xD8, 0x86, 0xA4, 0xDA, 0x0B, 0x1B, 0x47,
    0xA7, 0x2B, 0x60, 0x42, 0xA6, 0xB5, 0xBE, 0xE0,
};

static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *result)
{
    struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
    struct acpi_object_list input;
    union acpi_object params[4];
    union acpi_object *obj;
    int i, err;
    char args_buff[4];

    input.count = 4;
    input.pointer = params;
    params[0].type = ACPI_TYPE_BUFFER;
    params[0].buffer.length = sizeof(nouveau_op_dsm_muid);
    params[0].buffer.pointer = (char *)nouveau_op_dsm_muid;
    params[1].type = ACPI_TYPE_INTEGER;
    params[1].integer.value = 0x00000100;
    params[2].type = ACPI_TYPE_INTEGER;
    params[2].integer.value = func;
    params[3].type = ACPI_TYPE_BUFFER;
    params[3].buffer.length = 4;
    /* ACPI is little endian, AABBCCDD becomes {DD,CC,BB,AA} */
    for (i = 0; i < 4; i++)
        args_buff[i] = (arg >> i * 8) & 0xFF;
    params[3].buffer.pointer = args_buff;

    err = acpi_evaluate_object(handle, "_DSM", &input, &output);
    if (err) {
        printk(KERN_INFO "failed to evaluate _DSM: %d\n", err);
        return err;
    }

    obj = (union acpi_object *)output.pointer;

    if (obj->type == ACPI_TYPE_INTEGER)
        if (obj->integer.value == 0x80000002) {
            return -ENODEV;
        }

    if (obj->type == ACPI_TYPE_BUFFER) {
        if (obj->buffer.length == 4 && result) {
            *result = 0;
            *result |= obj->buffer.pointer[0];
            *result |= (obj->buffer.pointer[1] << 8);
            *result |= (obj->buffer.pointer[2] << 16);
            *result |= (obj->buffer.pointer[3] << 24);
        }
    }

    kfree(output.pointer);
    return 0;
}

static int nouveau_dsm(acpi_handle handle, int func, int arg, uint32_t *result)
{
    struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
    struct acpi_object_list input;
    union acpi_object params[4];
    union acpi_object *obj;
    int err;

    input.count = 4;
    input.pointer = params;
    params[0].type = ACPI_TYPE_BUFFER;
    params[0].buffer.length = sizeof(nouveau_dsm_muid);
    params[0].buffer.pointer = (char *)nouveau_dsm_muid;
    params[1].type = ACPI_TYPE_INTEGER;
    params[1].integer.value = 0x00000102;
    params[2].type = ACPI_TYPE_INTEGER;
    params[2].integer.value = func;
    params[3].type = ACPI_TYPE_INTEGER;
    params[3].integer.value = arg;

    err = acpi_evaluate_object(handle, "_DSM", &input, &output);
    if (err) {
        printk(KERN_INFO "failed to evaluate _DSM: %d\n", err);
        return err;
    }

    obj = (union acpi_object *)output.pointer;

    if (obj->type == ACPI_TYPE_INTEGER)
        if (obj->integer.value == 0x80000002)
            return -ENODEV;

    if (obj->type == ACPI_TYPE_BUFFER) {
        if (obj->buffer.length == 4 && result) {
            *result = 0;
            *result |= obj->buffer.pointer[0];
            *result |= (obj->buffer.pointer[1] << 8);
            *result |= (obj->buffer.pointer[2] << 16);
            *result |= (obj->buffer.pointer[3] << 24);
        }
    }

    kfree(output.pointer);
    return 0;
}

/* Returns 1 if a DSM function is usable and 0 otherwise */
static int nouveau_test_dsm(acpi_handle test_handle,
    int (*dsm_func)(acpi_handle, int, int, uint32_t *),
    int sfnc)
{
    u32 result = 0;

    /* Function 0 returns a Buffer containing available functions. The args
     * parameter is ignored for function 0, so just put 0 in it */
    if (dsm_func(test_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 */
    return result & 1 && result & (1 << sfnc);
}

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, NULL);
}

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, NULL);
    return 0;
}

static int nouveau_dsm_switchto(enum vga_switcheroo_client_id id)
{
    /* perhaps the _DSM functions are mutually exclusive, but prepare for
     * the future */
    if (!nouveau_dsm_priv.dsm_detected && nouveau_dsm_priv.optimus_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 && nouveau_dsm_priv.optimus_detected)
        return 0;

    return nouveau_dsm_set_discrete_state(nouveau_dsm_priv.dhandle, state);
}

static int 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 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 int nouveau_dsm_pci_probe(struct pci_dev *pdev)
{
    acpi_handle dhandle, nvidia_handle;
    acpi_status status;
    int retval = 0;

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

    status = acpi_get_handle(dhandle, "_DSM", &nvidia_handle);
    if (ACPI_FAILURE(status)) {
        return false;
    }

    if (nouveau_test_dsm(dhandle, nouveau_dsm, NOUVEAU_DSM_POWER))
        retval |= NOUVEAU_DSM_HAS_MUX;

    if (nouveau_test_dsm(dhandle, nouveau_optimus_dsm,
        NOUVEAU_DSM_OPTIMUS_FN))
        retval |= NOUVEAU_DSM_HAS_OPT;

    if (retval)
        nouveau_dsm_priv.dhandle = dhandle;

    return retval;
}

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;
    int has_dsm = 0;
    int has_optimus = 0;
    int vga_count = 0;
    bool guid_valid;
    int retval;
    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_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
        vga_count++;

        retval = nouveau_dsm_pci_probe(pdev);
        if (retval & NOUVEAU_DSM_HAS_MUX)
            has_dsm |= 1;
        if (retval & NOUVEAU_DSM_HAS_OPT)
            has_optimus = 1;
    }

    if (vga_count == 2 && has_dsm && guid_valid) {
        acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
            &buffer);
        printk(KERN_INFO "VGA switcheroo: detected DSM switching method %s handle\n",
            acpi_method_name);
        nouveau_dsm_priv.dsm_detected = true;
        ret = true;
    }

    if (has_optimus == 1) {
        acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
            &buffer);
        printk(KERN_INFO "VGA switcheroo: detected Optimus DSM method %s handle\n",
            acpi_method_name);
        nouveau_dsm_priv.optimus_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);
}

/* 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)
        return;

    nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_FN,
        NOUVEAU_DSM_OPTIMUS_ARGS, &result);
}

void nouveau_unregister_dsm_handler(void)
{
    if (nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.dsm_detected)
        vga_switcheroo_unregister_handler();
}

/* retrieve the ROM in 4k blocks */
static int nouveau_rom_call(acpi_handle rom_handle, uint8_t *bios,
                int offset, int len)
{
    acpi_status status;
    union acpi_object rom_arg_elements[2], *obj;
    struct acpi_object_list rom_arg;
    struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};

    rom_arg.count = 2;
    rom_arg.pointer = &rom_arg_elements[0];

    rom_arg_elements[0].type = ACPI_TYPE_INTEGER;
    rom_arg_elements[0].integer.value = offset;

    rom_arg_elements[1].type = ACPI_TYPE_INTEGER;
    rom_arg_elements[1].integer.value = len;

    status = acpi_evaluate_object(rom_handle, NULL, &rom_arg, &buffer);
    if (ACPI_FAILURE(status)) {
        printk(KERN_INFO "failed to evaluate ROM got %s\n", acpi_format_exception(status));
        return -ENODEV;
    }
    obj = (union acpi_object *)buffer.pointer;
    memcpy(bios+offset, obj->buffer.pointer, len);
    kfree(buffer.pointer);
    return len;
}

bool nouveau_acpi_rom_supported(struct pci_dev *pdev)
{
    acpi_status status;
    acpi_handle dhandle, rom_handle;

    if (!nouveau_dsm_priv.dsm_detected && !nouveau_dsm_priv.optimus_detected)
        return false;

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

    status = acpi_get_handle(dhandle, "_ROM", &rom_handle);
    if (ACPI_FAILURE(status))
        return false;

    nouveau_dsm_priv.rom_handle = rom_handle;
    return true;
}

int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len)
{
    return nouveau_rom_call(nouveau_dsm_priv.rom_handle, bios, offset, len);
}

void *
nouveau_acpi_edid(struct drm_device *dev, struct drm_connector *connector)
{
    struct acpi_device *acpidev;
    acpi_handle handle;
    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;
    }

    handle = DEVICE_ACPI_HANDLE(&dev->pdev->dev);
    if (!handle)
        return NULL;

    ret = acpi_bus_get_device(handle, &acpidev);
    if (ret)
        return NULL;

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

    return kmemdup(edid, EDID_LENGTH, GFP_KERNEL);
}