/*
 * Copyright © 2014 Intel Corporation
 *
 * 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:
 *    Daniel Vetter <daniel.vetter@ffwll.ch>
 *
 */

#include "i915_drv.h"
#include "intel_drv.h"

static bool ivb_can_enable_err_int(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_crtc *crtc;
	enum pipe pipe;

	assert_spin_locked(&dev_priv->irq_lock);

	for_each_pipe(dev_priv, pipe) {
		crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);

		if (crtc->cpu_fifo_underrun_disabled)
			return false;
	}

	return true;
}

static bool cpt_can_enable_serr_int(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	enum pipe pipe;
	struct intel_crtc *crtc;

	assert_spin_locked(&dev_priv->irq_lock);

	for_each_pipe(dev_priv, pipe) {
		crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);

		if (crtc->pch_fifo_underrun_disabled)
			return false;
	}

	return true;
}

void i9xx_check_fifo_underruns(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_crtc *crtc;

	spin_lock_irq(&dev_priv->irq_lock);

	for_each_intel_crtc(dev, crtc) {
		u32 reg = PIPESTAT(crtc->pipe);
		u32 pipestat;

		if (crtc->cpu_fifo_underrun_disabled)
			continue;

		pipestat = I915_READ(reg) & 0xffff0000;
		if ((pipestat & PIPE_FIFO_UNDERRUN_STATUS) == 0)
			continue;

		I915_WRITE(reg, pipestat | PIPE_FIFO_UNDERRUN_STATUS);
		POSTING_READ(reg);

		DRM_ERROR("pipe %c underrun\n", pipe_name(crtc->pipe));
	}

	spin_unlock_irq(&dev_priv->irq_lock);
}

static void i9xx_set_fifo_underrun_reporting(struct drm_device *dev,
					     enum pipe pipe,
					     bool enable, bool old)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	u32 reg = PIPESTAT(pipe);
	u32 pipestat = I915_READ(reg) & 0xffff0000;

	assert_spin_locked(&dev_priv->irq_lock);

	if (enable) {
		I915_WRITE(reg, pipestat | PIPE_FIFO_UNDERRUN_STATUS);
		POSTING_READ(reg);
	} else {
		if (old && pipestat & PIPE_FIFO_UNDERRUN_STATUS)
			DRM_ERROR("pipe %c underrun\n", pipe_name(pipe));
	}
}

static void ironlake_set_fifo_underrun_reporting(struct drm_device *dev,
						 enum pipe pipe, bool enable)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	uint32_t bit = (pipe == PIPE_A) ? DE_PIPEA_FIFO_UNDERRUN :
					  DE_PIPEB_FIFO_UNDERRUN;

	if (enable)
		ironlake_enable_display_irq(dev_priv, bit);
	else
		ironlake_disable_display_irq(dev_priv, bit);
}

static void ivybridge_set_fifo_underrun_reporting(struct drm_device *dev,
						  enum pipe pipe,
						  bool enable, bool old)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	if (enable) {
		I915_WRITE(GEN7_ERR_INT, ERR_INT_FIFO_UNDERRUN(pipe));

		if (!ivb_can_enable_err_int(dev))
			return;

		ironlake_enable_display_irq(dev_priv, DE_ERR_INT_IVB);
	} else {
		ironlake_disable_display_irq(dev_priv, DE_ERR_INT_IVB);

		if (old &&
		    I915_READ(GEN7_ERR_INT) & ERR_INT_FIFO_UNDERRUN(pipe)) {
			DRM_ERROR("uncleared fifo underrun on pipe %c\n",
				  pipe_name(pipe));
		}
	}
}

static void broadwell_set_fifo_underrun_reporting(struct drm_device *dev,
						  enum pipe pipe, bool enable)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	assert_spin_locked(&dev_priv->irq_lock);

	if (enable)
		dev_priv->de_irq_mask[pipe] &= ~GEN8_PIPE_FIFO_UNDERRUN;
	else
		dev_priv->de_irq_mask[pipe] |= GEN8_PIPE_FIFO_UNDERRUN;
	I915_WRITE(GEN8_DE_PIPE_IMR(pipe), dev_priv->de_irq_mask[pipe]);
	POSTING_READ(GEN8_DE_PIPE_IMR(pipe));
}

static void ibx_set_fifo_underrun_reporting(struct drm_device *dev,
					    enum transcoder pch_transcoder,
					    bool enable)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	uint32_t bit = (pch_transcoder == TRANSCODER_A) ?
		       SDE_TRANSA_FIFO_UNDER : SDE_TRANSB_FIFO_UNDER;

	if (enable)
		ibx_enable_display_interrupt(dev_priv, bit);
	else
		ibx_disable_display_interrupt(dev_priv, bit);
}

static void cpt_set_fifo_underrun_reporting(struct drm_device *dev,
					    enum transcoder pch_transcoder,
					    bool enable, bool old)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	if (enable) {
		I915_WRITE(SERR_INT,
			   SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder));

		if (!cpt_can_enable_serr_int(dev))
			return;

		ibx_enable_display_interrupt(dev_priv, SDE_ERROR_CPT);
	} else {
		ibx_disable_display_interrupt(dev_priv, SDE_ERROR_CPT);

		if (old && I915_READ(SERR_INT) &
		    SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder)) {
			DRM_ERROR("uncleared pch fifo underrun on pch transcoder %c\n",
				  transcoder_name(pch_transcoder));
		}
	}
}

/**
 * intel_set_cpu_fifo_underrun_reporting - enable/disable FIFO underrun messages
 * @dev: drm device
 * @pipe: pipe
 * @enable: true if we want to report FIFO underrun errors, false otherwise
 *
 * This function makes us disable or enable CPU fifo underruns for a specific
 * pipe. Notice that on some Gens (e.g. IVB, HSW), disabling FIFO underrun
 * reporting for one pipe may also disable all the other CPU error interruts for
 * the other pipes, due to the fact that there's just one interrupt mask/enable
 * bit for all the pipes.
 *
 * Returns the previous state of underrun reporting.
 */
static bool __intel_set_cpu_fifo_underrun_reporting(struct drm_device *dev,
						    enum pipe pipe, bool enable)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	bool old;

	assert_spin_locked(&dev_priv->irq_lock);

	old = !intel_crtc->cpu_fifo_underrun_disabled;
	intel_crtc->cpu_fifo_underrun_disabled = !enable;

	if (HAS_GMCH_DISPLAY(dev))
		i9xx_set_fifo_underrun_reporting(dev, pipe, enable, old);
	else if (IS_GEN5(dev) || IS_GEN6(dev))
		ironlake_set_fifo_underrun_reporting(dev, pipe, enable);
	else if (IS_GEN7(dev))
		ivybridge_set_fifo_underrun_reporting(dev, pipe, enable, old);
	else if (IS_GEN8(dev) || IS_GEN9(dev))
		broadwell_set_fifo_underrun_reporting(dev, pipe, enable);

	return old;
}

bool intel_set_cpu_fifo_underrun_reporting(struct drm_device *dev,
					   enum pipe pipe, bool enable)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	unsigned long flags;
	bool ret;

	spin_lock_irqsave(&dev_priv->irq_lock, flags);
	ret = __intel_set_cpu_fifo_underrun_reporting(dev, pipe, enable);
	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);

	return ret;
}

bool __cpu_fifo_underrun_reporting_enabled(struct drm_device *dev,
					   enum pipe pipe)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);

	return !intel_crtc->cpu_fifo_underrun_disabled;
}

/**
 * intel_set_pch_fifo_underrun_reporting - enable/disable FIFO underrun messages
 * @dev: drm device
 * @pch_transcoder: the PCH transcoder (same as pipe on IVB and older)
 * @enable: true if we want to report FIFO underrun errors, false otherwise
 *
 * This function makes us disable or enable PCH fifo underruns for a specific
 * PCH transcoder. Notice that on some PCHs (e.g. CPT/PPT), disabling FIFO
 * underrun reporting for one transcoder may also disable all the other PCH
 * error interruts for the other transcoders, due to the fact that there's just
 * one interrupt mask/enable bit for all the transcoders.
 *
 * Returns the previous state of underrun reporting.
 */
bool intel_set_pch_fifo_underrun_reporting(struct drm_device *dev,
					   enum transcoder pch_transcoder,
					   bool enable)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pch_transcoder];
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	unsigned long flags;
	bool old;

	/*
	 * NOTE: Pre-LPT has a fixed cpu pipe -> pch transcoder mapping, but LPT
	 * has only one pch transcoder A that all pipes can use. To avoid racy
	 * pch transcoder -> pipe lookups from interrupt code simply store the
	 * underrun statistics in crtc A. Since we never expose this anywhere
	 * nor use it outside of the fifo underrun code here using the "wrong"
	 * crtc on LPT won't cause issues.
	 */

	spin_lock_irqsave(&dev_priv->irq_lock, flags);

	old = !intel_crtc->pch_fifo_underrun_disabled;
	intel_crtc->pch_fifo_underrun_disabled = !enable;

	if (HAS_PCH_IBX(dev))
		ibx_set_fifo_underrun_reporting(dev, pch_transcoder, enable);
	else
		cpt_set_fifo_underrun_reporting(dev, pch_transcoder, enable, old);

	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
	return old;
}