/**
* \file drm_irq.c
* IRQ support
*
* \author Rickard E. (Rik) Faith <faith@valinux.com>
* \author Gareth Hughes <gareth@valinux.com>
*/
/*
* Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
*
* Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* 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
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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.
*/
#include <drm/drmP.h>
#include <asm/div64.h>
//#include "drm_trace.h"
//#include <linux/interrupt.h> /* For task queue support */
#include <linux/slab.h>
//#include <linux/vgaarb.h>
#include <linux/export.h>
/* Access macro for slots in vblank timestamp ringbuffer. */
#define vblanktimestamp(dev, crtc, count) ( \
(dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
((count) % DRM_VBLANKTIME_RBSIZE)])
/* Retry timestamp calculation up to 3 times to satisfy
* drm_timestamp_precision before giving up.
*/
#define DRM_TIMESTAMP_MAXRETRIES 3
/* Threshold in nanoseconds for detection of redundant
* vblank irq in drm_handle_vblank(). 1 msec should be ok.
*/
#define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
static inline u64 div_u64(u64 dividend, u32 divisor)
{
u32 remainder;
return div_u64_rem(dividend, divisor, &remainder);
}
u64 div64_u64(u64 dividend, u64 divisor)
{
u32 high, d;
high = divisor >> 32;
if (high) {
unsigned int shift = fls(high);
d = divisor >> shift;
dividend >>= shift;
} else
d = divisor;
return div_u64(dividend, d);
}
/**
* drm_calc_timestamping_constants - Calculate and
* store various constants which are later needed by
* vblank and swap-completion timestamping, e.g, by
* drm_calc_vbltimestamp_from_scanoutpos().
* They are derived from crtc's true scanout timing,
* so they take things like panel scaling or other
* adjustments into account.
*
* @crtc drm_crtc whose timestamp constants should be updated.
*
*/
void drm_calc_timestamping_constants(struct drm_crtc *crtc)
{
s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
u64 dotclock;
/* Dot clock in Hz: */
dotclock
= (u64
) crtc
->hwmode.
clock * 1000;
/* Fields of interlaced scanout modes are only halve a frame duration.
* Double the dotclock to get halve the frame-/line-/pixelduration.
*/
if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
dotclock *= 2;
/* Valid dotclock? */
if (dotclock > 0) {
/* Convert scanline length in pixels and video dot clock to
* line duration, frame duration and pixel duration in
* nanoseconds:
*/
pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
linedur_ns = (s64) div64_u64(((u64) crtc->hwmode.crtc_htotal *
1000000000), dotclock);
framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns;
} else
DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
crtc->base.id);
crtc->pixeldur_ns = pixeldur_ns;
crtc->linedur_ns = linedur_ns;
crtc->framedur_ns = framedur_ns;
DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
crtc->base.id, crtc->hwmode.crtc_htotal,
crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
(int) linedur_ns, (int) pixeldur_ns);
}
/**
* drm_vblank_pre_modeset - account for vblanks across mode sets
* @dev: DRM device
* @crtc: CRTC in question
*
* Account for vblank events across mode setting events, which will likely
* reset the hardware frame counter.
*/
void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
{
#if 0
/* vblank is not initialized (IRQ not installed ?) */
if (!dev->num_crtcs)
return;
/*
* To avoid all the problems that might happen if interrupts
* were enabled/disabled around or between these calls, we just
* have the kernel take a reference on the CRTC (just once though
* to avoid corrupting the count if multiple, mismatch calls occur),
* so that interrupts remain enabled in the interim.
*/
if (!dev->vblank_inmodeset[crtc]) {
dev->vblank_inmodeset[crtc] = 0x1;
if (drm_vblank_get(dev, crtc) == 0)
dev->vblank_inmodeset[crtc] |= 0x2;
}
#endif
}
EXPORT_SYMBOL(drm_vblank_pre_modeset);
void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
{
#if 0
unsigned long irqflags;
if (dev->vblank_inmodeset[crtc]) {
spin_lock_irqsave(&dev->vbl_lock, irqflags);
dev->vblank_disable_allowed = 1;
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
if (dev->vblank_inmodeset[crtc] & 0x2)
drm_vblank_put(dev, crtc);
dev->vblank_inmodeset[crtc] = 0;
}
#endif
}
EXPORT_SYMBOL(drm_vblank_post_modeset);