/*
 * Copyright © 2006-2010 Intel Corporation
 * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *      Eric Anholt <eric@anholt.net>
 *      Dave Airlie <airlied@linux.ie>
 *      Jesse Barnes <jesse.barnes@intel.com>
 *      Chris Wilson <chris@chris-wilson.co.uk>
 */

#include "intel_drv.h"

#define PCI_LBPC 0xf4 /* legacy/combination backlight modes */

void
intel_fixed_panel_mode(struct drm_display_mode *fixed_mode,
                       struct drm_display_mode *adjusted_mode)
{
        adjusted_mode->hdisplay = fixed_mode->hdisplay;
        adjusted_mode->hsync_start = fixed_mode->hsync_start;
        adjusted_mode->hsync_end = fixed_mode->hsync_end;
        adjusted_mode->htotal = fixed_mode->htotal;

        adjusted_mode->vdisplay = fixed_mode->vdisplay;
        adjusted_mode->vsync_start = fixed_mode->vsync_start;
        adjusted_mode->vsync_end = fixed_mode->vsync_end;
        adjusted_mode->vtotal = fixed_mode->vtotal;

        adjusted_mode->clock = fixed_mode->clock;

        drm_mode_set_crtcinfo(adjusted_mode, CRTC_INTERLACE_HALVE_V);
}

/* adjusted_mode has been preset to be the panel's fixed mode */
void
intel_pch_panel_fitting(struct drm_device *dev,
                        int fitting_mode,
                        struct drm_display_mode *mode,
                        struct drm_display_mode *adjusted_mode)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int x, y, width, height;

        x = y = width = height = 0;

        /* Native modes don't need fitting */
        if (adjusted_mode->hdisplay == mode->hdisplay &&
            adjusted_mode->vdisplay == mode->vdisplay)
                goto done;

        switch (fitting_mode) {
        case DRM_MODE_SCALE_CENTER:
                width = mode->hdisplay;
                height = mode->vdisplay;
                x = (adjusted_mode->hdisplay - width + 1)/2;
                y = (adjusted_mode->vdisplay - height + 1)/2;
                break;

        case DRM_MODE_SCALE_ASPECT:
                /* Scale but preserve the aspect ratio */
                {
                        u32 scaled_width = adjusted_mode->hdisplay * mode->vdisplay;
                        u32 scaled_height = mode->hdisplay * adjusted_mode->vdisplay;
                        if (scaled_width > scaled_height) { /* pillar */
                                width = scaled_height / mode->vdisplay;
                                if (width & 1)
                                        width++;
                                x = (adjusted_mode->hdisplay - width + 1) / 2;
                                y = 0;
                                height = adjusted_mode->vdisplay;
                        } else if (scaled_width < scaled_height) { /* letter */
                                height = scaled_width / mode->hdisplay;
                                if (height & 1)
                                    height++;
                                y = (adjusted_mode->vdisplay - height + 1) / 2;
                                x = 0;
                                width = adjusted_mode->hdisplay;
                        } else {
                                x = y = 0;
                                width = adjusted_mode->hdisplay;
                                height = adjusted_mode->vdisplay;
                        }
                }
                break;

        default:
        case DRM_MODE_SCALE_FULLSCREEN:
                x = y = 0;
                width = adjusted_mode->hdisplay;
                height = adjusted_mode->vdisplay;
                break;
        }

done:
        dev_priv->pch_pf_pos = (x << 16) | y;
        dev_priv->pch_pf_size = (width << 16) | height;
}

static int is_backlight_combination_mode(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (INTEL_INFO(dev)->gen >= 4)
                return I915_READ(BLC_PWM_CTL2) & BLM_COMBINATION_MODE;

        if (IS_GEN2(dev))
                return I915_READ(BLC_PWM_CTL) & BLM_LEGACY_MODE;

        return 0;
}

static u32 i915_read_blc_pwm_ctl(struct drm_i915_private *dev_priv)
{
        u32 val;

        /* Restore the CTL value if it lost, e.g. GPU reset */

        if (HAS_PCH_SPLIT(dev_priv->dev)) {
                val = I915_READ(BLC_PWM_PCH_CTL2);
                if (dev_priv->saveBLC_PWM_CTL2 == 0) {
                        dev_priv->saveBLC_PWM_CTL2 = val;
                } else if (val == 0) {
                        I915_WRITE(BLC_PWM_PCH_CTL2,
                                   dev_priv->saveBLC_PWM_CTL);
                        val = dev_priv->saveBLC_PWM_CTL;
                }
        } else {
                val = I915_READ(BLC_PWM_CTL);
                if (dev_priv->saveBLC_PWM_CTL == 0) {
                        dev_priv->saveBLC_PWM_CTL = val;
                        dev_priv->saveBLC_PWM_CTL2 = I915_READ(BLC_PWM_CTL2);
                } else if (val == 0) {
                        I915_WRITE(BLC_PWM_CTL,
                                   dev_priv->saveBLC_PWM_CTL);
                        I915_WRITE(BLC_PWM_CTL2,
                                   dev_priv->saveBLC_PWM_CTL2);
                        val = dev_priv->saveBLC_PWM_CTL;
                }
        }

        return val;
}

u32 intel_panel_get_max_backlight(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 max;

        max = i915_read_blc_pwm_ctl(dev_priv);
        if (max == 0) {
                /* XXX add code here to query mode clock or hardware clock
                 * and program max PWM appropriately.
                 */
                printk_once(KERN_WARNING "fixme: max PWM is zero.\n");
                return 1;
        }

        if (HAS_PCH_SPLIT(dev)) {
                max >>= 16;
        } else {
                if (INTEL_INFO(dev)->gen < 4)
                        max >>= 17;
                else
                        max >>= 16;

                if (is_backlight_combination_mode(dev))
                        max *= 0xff;
        }

        DRM_DEBUG_DRIVER("max backlight PWM = %d\n", max);
        return max;
}

u32 intel_panel_get_backlight(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 val;

        if (HAS_PCH_SPLIT(dev)) {
                val = I915_READ(BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
        } else {
                val = I915_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
                if (INTEL_INFO(dev)->gen < 4)
                        val >>= 1;

                if (is_backlight_combination_mode(dev)) {
                        u8 lbpc;

                        pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc);
                        val *= lbpc;
                }
        }

        DRM_DEBUG_DRIVER("get backlight PWM = %d\n", val);
        return val;
}

static void intel_pch_panel_set_backlight(struct drm_device *dev, u32 level)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 val = I915_READ(BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
        I915_WRITE(BLC_PWM_CPU_CTL, val | level);
}

static void intel_panel_actually_set_backlight(struct drm_device *dev, u32 level)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 tmp;

        DRM_DEBUG_DRIVER("set backlight PWM = %d\n", level);

        if (HAS_PCH_SPLIT(dev))
                return intel_pch_panel_set_backlight(dev, level);

        if (is_backlight_combination_mode(dev)) {
                u32 max = intel_panel_get_max_backlight(dev);
                u8 lbpc;

                lbpc = level * 0xfe / max + 1;
                level /= lbpc;
                pci_write_config_byte(dev->pdev, PCI_LBPC, lbpc);
        }

        tmp = I915_READ(BLC_PWM_CTL);
        if (INTEL_INFO(dev)->gen < 4) 
                level <<= 1;
        tmp &= ~BACKLIGHT_DUTY_CYCLE_MASK;
        I915_WRITE(BLC_PWM_CTL, tmp | level);
}

void intel_panel_set_backlight(struct drm_device *dev, u32 level)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        dev_priv->backlight_level = level;
        if (dev_priv->backlight_enabled)
                intel_panel_actually_set_backlight(dev, level);
}

void intel_panel_disable_backlight(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        dev_priv->backlight_enabled = false;
        intel_panel_actually_set_backlight(dev, 0);
}

void intel_panel_enable_backlight(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (dev_priv->backlight_level == 0)
                dev_priv->backlight_level = intel_panel_get_max_backlight(dev);

        dev_priv->backlight_enabled = true;
        intel_panel_actually_set_backlight(dev, dev_priv->backlight_level);
}

static void intel_panel_init_backlight(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        dev_priv->backlight_level = intel_panel_get_backlight(dev);
        dev_priv->backlight_enabled = dev_priv->backlight_level != 0;
}

enum drm_connector_status
intel_panel_detect(struct drm_device *dev)
{
#if 0
        struct drm_i915_private *dev_priv = dev->dev_private;
#endif

        if (i915_panel_ignore_lid)
                return i915_panel_ignore_lid > 0 ?
                        connector_status_connected :
                        connector_status_disconnected;

        /* opregion lid state on HP 2540p is wrong at boot up,
         * appears to be either the BIOS or Linux ACPI fault */
#if 0
        /* Assume that the BIOS does not lie through the OpRegion... */
        if (dev_priv->opregion.lid_state)
                return ioread32(dev_priv->opregion.lid_state) & 0x1 ?
                        connector_status_connected :
                        connector_status_disconnected;
#endif

        return connector_status_unknown;
}

#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
static int intel_panel_update_status(struct backlight_device *bd)
{
        struct drm_device *dev = bl_get_data(bd);
        intel_panel_set_backlight(dev, bd->props.brightness);
        return 0;
}

static int intel_panel_get_brightness(struct backlight_device *bd)
{
        struct drm_device *dev = bl_get_data(bd);
        struct drm_i915_private *dev_priv = dev->dev_private;
        return dev_priv->backlight_level;
}

static const struct backlight_ops intel_panel_bl_ops = {
        .update_status = intel_panel_update_status,
        .get_brightness = intel_panel_get_brightness,
};

int intel_panel_setup_backlight(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct backlight_properties props;
        struct drm_connector *connector;

        intel_panel_init_backlight(dev);

        if (dev_priv->int_lvds_connector)
                connector = dev_priv->int_lvds_connector;
        else if (dev_priv->int_edp_connector)
                connector = dev_priv->int_edp_connector;
        else
                return -ENODEV;

        props.type = BACKLIGHT_RAW;
        props.max_brightness = intel_panel_get_max_backlight(dev);
        dev_priv->backlight =
                backlight_device_register("intel_backlight",
                                          &connector->kdev, dev,
                                          &intel_panel_bl_ops, &props);

        if (IS_ERR(dev_priv->backlight)) {
                DRM_ERROR("Failed to register backlight: %ld\n",
                          PTR_ERR(dev_priv->backlight));
                dev_priv->backlight = NULL;
                return -ENODEV;
        }
        dev_priv->backlight->props.brightness = intel_panel_get_backlight(dev);
        return 0;
}

void intel_panel_destroy_backlight(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        if (dev_priv->backlight)
                backlight_device_unregister(dev_priv->backlight);
}
#else
int intel_panel_setup_backlight(struct drm_device *dev)
{
        intel_panel_init_backlight(dev);
        return 0;
}

void intel_panel_destroy_backlight(struct drm_device *dev)
{
        return;
}
#endif