/**************************************************************************
 * Copyright (c) 2009-2011, Intel Corporation.
 * All Rights Reserved.
 *
 * 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:
 *    Benjamin Defnet <benjamin.r.defnet@intel.com>
 *    Rajesh Poornachandran <rajesh.poornachandran@intel.com>
 * Massively reworked
 *    Alan Cox <alan@linux.intel.com>
 */

#include "power.h"
#include "psb_drv.h"
#include "psb_reg.h"
#include "psb_intel_reg.h"
#include <linux/mutex.h>
#include <linux/pm_runtime.h>

static struct mutex power_mutex;        /* Serialize power ops */
static spinlock_t power_ctrl_lock;      /* Serialize power claim */

/**
 *      gma_power_init          -       initialise power manager
 *      @dev: our device
 *
 *      Set up for power management tracking of our hardware.
 */
void gma_power_init(struct drm_device *dev)
{
        struct drm_psb_private *dev_priv = dev->dev_private;

        /* FIXME: Move APM/OSPM base into relevant device code */
        dev_priv->apm_base = dev_priv->apm_reg & 0xffff;
        dev_priv->ospm_base &= 0xffff;

        dev_priv->display_power = true; /* We start active */
        dev_priv->display_count = 0;    /* Currently no users */
        dev_priv->suspended = false;    /* And not suspended */
        spin_lock_init(&power_ctrl_lock);
        mutex_init(&power_mutex);

        if (dev_priv->ops->init_pm)
                dev_priv->ops->init_pm(dev);
}

/**
 *      gma_power_uninit        -       end power manager
 *      @dev: device to end for
 *
 *      Undo the effects of gma_power_init
 */
void gma_power_uninit(struct drm_device *dev)
{
        pm_runtime_disable(&dev->pdev->dev);
        pm_runtime_set_suspended(&dev->pdev->dev);
}

/**
 *      gma_suspend_display     -       suspend the display logic
 *      @dev: our DRM device
 *
 *      Suspend the display logic of the graphics interface
 */
static void gma_suspend_display(struct drm_device *dev)
{
        struct drm_psb_private *dev_priv = dev->dev_private;

        if (dev_priv->suspended)
                return;
        dev_priv->ops->save_regs(dev);
        dev_priv->ops->power_down(dev);
        dev_priv->display_power = false;
}

/**
 *      gma_resume_display      -       resume display side logic
 *
 *      Resume the display hardware restoring state and enabling
 *      as necessary.
 */
static void gma_resume_display(struct pci_dev *pdev)
{
        struct drm_device *dev = pci_get_drvdata(pdev);
        struct drm_psb_private *dev_priv = dev->dev_private;

        /* turn on the display power island */
        dev_priv->ops->power_up(dev);
        dev_priv->suspended = false;
        dev_priv->display_power = true;

        PSB_WVDC32(dev_priv->pge_ctl | _PSB_PGETBL_ENABLED, PSB_PGETBL_CTL);
        pci_write_config_word(pdev, PSB_GMCH_CTRL,
                        dev_priv->gmch_ctrl | _PSB_GMCH_ENABLED);
        dev_priv->ops->restore_regs(dev);
}

/**
 *      gma_suspend_pci         -       suspend PCI side
 *      @pdev: PCI device
 *
 *      Perform the suspend processing on our PCI device state
 */
static void gma_suspend_pci(struct pci_dev *pdev)
{
        struct drm_device *dev = pci_get_drvdata(pdev);
        struct drm_psb_private *dev_priv = dev->dev_private;
        int bsm, vbt;

        if (dev_priv->suspended)
                return;

        pci_save_state(pdev);
        pci_read_config_dword(pdev, 0x5C, &bsm);
        dev_priv->regs.saveBSM = bsm;
        pci_read_config_dword(pdev, 0xFC, &vbt);
        dev_priv->regs.saveVBT = vbt;
        pci_read_config_dword(pdev, PSB_PCIx_MSI_ADDR_LOC, &dev_priv->msi_addr);
        pci_read_config_dword(pdev, PSB_PCIx_MSI_DATA_LOC, &dev_priv->msi_data);

        pci_disable_device(pdev);
        pci_set_power_state(pdev, PCI_D3hot);

        dev_priv->suspended = true;
}

/**
 *      gma_resume_pci          -       resume helper
 *      @dev: our PCI device
 *
 *      Perform the resume processing on our PCI device state - rewrite
 *      register state and re-enable the PCI device
 */
static bool gma_resume_pci(struct pci_dev *pdev)
{
        struct drm_device *dev = pci_get_drvdata(pdev);
        struct drm_psb_private *dev_priv = dev->dev_private;
        int ret;

        if (!dev_priv->suspended)
                return true;

        pci_set_power_state(pdev, PCI_D0);
        pci_restore_state(pdev);
        pci_write_config_dword(pdev, 0x5c, dev_priv->regs.saveBSM);
        pci_write_config_dword(pdev, 0xFC, dev_priv->regs.saveVBT);
        /* restoring MSI address and data in PCIx space */
        pci_write_config_dword(pdev, PSB_PCIx_MSI_ADDR_LOC, dev_priv->msi_addr);
        pci_write_config_dword(pdev, PSB_PCIx_MSI_DATA_LOC, dev_priv->msi_data);
        ret = pci_enable_device(pdev);

        if (ret != 0)
                dev_err(&pdev->dev, "pci_enable failed: %d\n", ret);
        else
                dev_priv->suspended = false;
        return !dev_priv->suspended;
}

/**
 *      gma_power_suspend               -       bus callback for suspend
 *      @pdev: our PCI device
 *      @state: suspend type
 *
 *      Called back by the PCI layer during a suspend of the system. We
 *      perform the necessary shut down steps and save enough state that
 *      we can undo this when resume is called.
 */
int gma_power_suspend(struct device *_dev)
{
        struct pci_dev *pdev = container_of(_dev, struct pci_dev, dev);
        struct drm_device *dev = pci_get_drvdata(pdev);
        struct drm_psb_private *dev_priv = dev->dev_private;

        mutex_lock(&power_mutex);
        if (!dev_priv->suspended) {
                if (dev_priv->display_count) {
                        mutex_unlock(&power_mutex);
                        dev_err(dev->dev, "GPU hardware busy, cannot suspend\n");
                        return -EBUSY;
                }
                psb_irq_uninstall(dev);
                gma_suspend_display(dev);
                gma_suspend_pci(pdev);
        }
        mutex_unlock(&power_mutex);
        return 0;
}

/**
 *      gma_power_resume                -       resume power
 *      @pdev: PCI device
 *
 *      Resume the PCI side of the graphics and then the displays
 */
int gma_power_resume(struct device *_dev)
{
        struct pci_dev *pdev = container_of(_dev, struct pci_dev, dev);
        struct drm_device *dev = pci_get_drvdata(pdev);

        mutex_lock(&power_mutex);
        gma_resume_pci(pdev);
        gma_resume_display(pdev);
        psb_irq_preinstall(dev);
        psb_irq_postinstall(dev);
        mutex_unlock(&power_mutex);
        return 0;
}

/**
 *      gma_power_is_on         -       returne true if power is on
 *      @dev: our DRM device
 *
 *      Returns true if the display island power is on at this moment
 */
bool gma_power_is_on(struct drm_device *dev)
{
        struct drm_psb_private *dev_priv = dev->dev_private;
        return dev_priv->display_power;
}

/**
 *      gma_power_begin         -       begin requiring power
 *      @dev: our DRM device
 *      @force_on: true to force power on
 *
 *      Begin an action that requires the display power island is enabled.
 *      We refcount the islands.
 */
bool gma_power_begin(struct drm_device *dev, bool force_on)
{
        struct drm_psb_private *dev_priv = dev->dev_private;
        int ret;
        unsigned long flags;

        spin_lock_irqsave(&power_ctrl_lock, flags);
        /* Power already on ? */
        if (dev_priv->display_power) {
                dev_priv->display_count++;
                pm_runtime_get(&dev->pdev->dev);
                spin_unlock_irqrestore(&power_ctrl_lock, flags);
                return true;
        }
        if (force_on == false)
                goto out_false;

        /* Ok power up needed */
        ret = gma_resume_pci(dev->pdev);
        if (ret == 0) {
                psb_irq_preinstall(dev);
                psb_irq_postinstall(dev);
                pm_runtime_get(&dev->pdev->dev);
                dev_priv->display_count++;
                spin_unlock_irqrestore(&power_ctrl_lock, flags);
                return true;
        }
out_false:
        spin_unlock_irqrestore(&power_ctrl_lock, flags);
        return false;
}

/**
 *      gma_power_end           -       end use of power
 *      @dev: Our DRM device
 *
 *      Indicate that one of our gma_power_begin() requested periods when
 *      the diplay island power is needed has completed.
 */
void gma_power_end(struct drm_device *dev)
{
        struct drm_psb_private *dev_priv = dev->dev_private;
        unsigned long flags;
        spin_lock_irqsave(&power_ctrl_lock, flags);
        dev_priv->display_count--;
        WARN_ON(dev_priv->display_count < 0);
        spin_unlock_irqrestore(&power_ctrl_lock, flags);
        pm_runtime_put(&dev->pdev->dev);
}

int psb_runtime_suspend(struct device *dev)
{
        return gma_power_suspend(dev);
}

int psb_runtime_resume(struct device *dev)
{
        return gma_power_resume(dev);
}

int psb_runtime_idle(struct device *dev)
{
        struct drm_device *drmdev = pci_get_drvdata(to_pci_dev(dev));
        struct drm_psb_private *dev_priv = drmdev->dev_private;
        if (dev_priv->display_count)
                return 0;
        else
                return 1;
}