/**************************************************************************
* Copyright (c) 2007, Intel Corporation.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
* Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
* develop this driver.
*
**************************************************************************/
/*
*/
#include <drm/drmP.h>
#include "psb_drv.h"
#include "psb_reg.h"
#include "psb_intel_reg.h"
#include "power.h"
#include "psb_irq.h"
#include "mdfld_output.h"
/*
* inline functions
*/
static inline u32
psb_pipestat(int pipe)
{
if (pipe == 0)
return PIPEASTAT;
if (pipe == 1)
return PIPEBSTAT;
if (pipe == 2)
return PIPECSTAT;
BUG();
}
static inline u32
mid_pipe_event(int pipe)
{
if (pipe == 0)
return _PSB_PIPEA_EVENT_FLAG;
if (pipe == 1)
return _MDFLD_PIPEB_EVENT_FLAG;
if (pipe == 2)
return _MDFLD_PIPEC_EVENT_FLAG;
BUG();
}
static inline u32
mid_pipe_vsync(int pipe)
{
if (pipe == 0)
return _PSB_VSYNC_PIPEA_FLAG;
if (pipe == 1)
return _PSB_VSYNC_PIPEB_FLAG;
if (pipe == 2)
return _MDFLD_PIPEC_VBLANK_FLAG;
BUG();
}
static inline u32
mid_pipeconf(int pipe)
{
if (pipe == 0)
return PIPEACONF;
if (pipe == 1)
return PIPEBCONF;
if (pipe == 2)
return PIPECCONF;
BUG();
}
void
psb_enable_pipestat(struct drm_psb_private *dev_priv, int pipe, u32 mask)
{
if ((dev_priv->pipestat[pipe] & mask) != mask) {
u32 reg = psb_pipestat(pipe);
dev_priv->pipestat[pipe] |= mask;
/* Enable the interrupt, clear any pending status */
if (gma_power_begin(dev_priv->dev, false)) {
u32 writeVal = PSB_RVDC32(reg);
writeVal |= (mask | (mask >> 16));
PSB_WVDC32(writeVal, reg);
(void) PSB_RVDC32(reg);
gma_power_end(dev_priv->dev);
}
}
}
void
psb_disable_pipestat(struct drm_psb_private *dev_priv, int pipe, u32 mask)
{
if ((dev_priv->pipestat[pipe] & mask) != 0) {
u32 reg = psb_pipestat(pipe);
dev_priv->pipestat[pipe] &= ~mask;
if (gma_power_begin(dev_priv->dev, false)) {
u32 writeVal = PSB_RVDC32(reg);
writeVal &= ~mask;
PSB_WVDC32(writeVal, reg);
(void) PSB_RVDC32(reg);
gma_power_end(dev_priv->dev);
}
}
}
static void mid_enable_pipe_event(struct drm_psb_private *dev_priv, int pipe)
{
if (gma_power_begin(dev_priv->dev, false)) {
u32 pipe_event = mid_pipe_event(pipe);
dev_priv->vdc_irq_mask |= pipe_event;
PSB_WVDC32(~dev_priv->vdc_irq_mask, PSB_INT_MASK_R);
PSB_WVDC32(dev_priv->vdc_irq_mask, PSB_INT_ENABLE_R);
gma_power_end(dev_priv->dev);
}
}
static void mid_disable_pipe_event(struct drm_psb_private *dev_priv, int pipe)
{
if (dev_priv->pipestat[pipe] == 0) {
if (gma_power_begin(dev_priv->dev, false)) {
u32 pipe_event = mid_pipe_event(pipe);
dev_priv->vdc_irq_mask &= ~pipe_event;
PSB_WVDC32(~dev_priv->vdc_irq_mask, PSB_INT_MASK_R);
PSB_WVDC32(dev_priv->vdc_irq_mask, PSB_INT_ENABLE_R);
gma_power_end(dev_priv->dev);
}
}
}
/**
* Display controller interrupt handler for pipe event.
*
*/
static void mid_pipe_event_handler(struct drm_device *dev, int pipe)
{
struct drm_psb_private *dev_priv =
(struct drm_psb_private *) dev->dev_private;
uint32_t pipe_stat_val = 0;
uint32_t pipe_stat_reg = psb_pipestat(pipe);
uint32_t pipe_enable = dev_priv->pipestat[pipe];
uint32_t pipe_status = dev_priv->pipestat[pipe] >> 16;
uint32_t pipe_clear;
uint32_t i = 0;
spin_lock(&dev_priv->irqmask_lock);
pipe_stat_val = PSB_RVDC32(pipe_stat_reg);
pipe_stat_val &= pipe_enable | pipe_status;
pipe_stat_val &= pipe_stat_val >> 16;
spin_unlock(&dev_priv->irqmask_lock);
/* Clear the 2nd level interrupt status bits
* Sometimes the bits are very sticky so we repeat until they unstick */
for (i = 0; i < 0xffff; i++) {
PSB_WVDC32(PSB_RVDC32(pipe_stat_reg), pipe_stat_reg);
pipe_clear = PSB_RVDC32(pipe_stat_reg) & pipe_status;
if (pipe_clear == 0)
break;
}
if (pipe_clear)
dev_err(dev->dev,
"%s, can't clear status bits for pipe %d, its value = 0x%x.\n",
__func__, pipe, PSB_RVDC32(pipe_stat_reg));
if (pipe_stat_val & PIPE_VBLANK_STATUS)
drm_handle_vblank(dev, pipe);
if (pipe_stat_val & PIPE_TE_STATUS)
drm_handle_vblank(dev, pipe);
}
/*
* Display controller interrupt handler.
*/
static void psb_vdc_interrupt(struct drm_device *dev, uint32_t vdc_stat)
{
if (vdc_stat & _PSB_IRQ_ASLE)
psb_intel_opregion_asle_intr(dev);
if (vdc_stat & _PSB_VSYNC_PIPEA_FLAG)
mid_pipe_event_handler(dev, 0);
if (vdc_stat & _PSB_VSYNC_PIPEB_FLAG)
mid_pipe_event_handler(dev, 1);
}
/*
* SGX interrupt handler
*/
static void psb_sgx_interrupt(struct drm_device *dev, u32 stat_1, u32 stat_2)
{
struct drm_psb_private *dev_priv = dev->dev_private;
u32 val, addr;
int error = false;
if (stat_1 & _PSB_CE_TWOD_COMPLETE)
val = PSB_RSGX32(PSB_CR_2D_BLIT_STATUS);
if (stat_2 & _PSB_CE2_BIF_REQUESTER_FAULT) {
val = PSB_RSGX32(PSB_CR_BIF_INT_STAT);
addr = PSB_RSGX32(PSB_CR_BIF_FAULT);
if (val) {
if (val & _PSB_CBI_STAT_PF_N_RW)
DRM_ERROR("SGX MMU page fault:");
else
DRM_ERROR("SGX MMU read / write protection fault:");
if (val & _PSB_CBI_STAT_FAULT_CACHE)
DRM_ERROR("\tCache requestor");
if (val & _PSB_CBI_STAT_FAULT_TA)
DRM_ERROR("\tTA requestor");
if (val & _PSB_CBI_STAT_FAULT_VDM)
DRM_ERROR("\tVDM requestor");
if (val & _PSB_CBI_STAT_FAULT_2D)
DRM_ERROR("\t2D requestor");
if (val & _PSB_CBI_STAT_FAULT_PBE)
DRM_ERROR("\tPBE requestor");
if (val & _PSB_CBI_STAT_FAULT_TSP)
DRM_ERROR("\tTSP requestor");
if (val & _PSB_CBI_STAT_FAULT_ISP)
DRM_ERROR("\tISP requestor");
if (val & _PSB_CBI_STAT_FAULT_USSEPDS)
DRM_ERROR("\tUSSEPDS requestor");
if (val & _PSB_CBI_STAT_FAULT_HOST)
DRM_ERROR("\tHost requestor");
DRM_ERROR("\tMMU failing address is 0x%08x.\n",
(unsigned int)addr);
error = true;
}
}
/* Clear bits */
PSB_WSGX32(stat_1, PSB_CR_EVENT_HOST_CLEAR);
PSB_WSGX32(stat_2, PSB_CR_EVENT_HOST_CLEAR2);
PSB_RSGX32(PSB_CR_EVENT_HOST_CLEAR2);
}
irqreturn_t psb_irq_handler(int irq, void *arg)
{
struct drm_device *dev = arg;
struct drm_psb_private *dev_priv = dev->dev_private;
uint32_t vdc_stat, dsp_int = 0, sgx_int = 0, hotplug_int = 0;
u32 sgx_stat_1, sgx_stat_2;
int handled = 0;
spin_lock(&dev_priv->irqmask_lock);
vdc_stat = PSB_RVDC32(PSB_INT_IDENTITY_R);
if (vdc_stat & (_PSB_PIPE_EVENT_FLAG|_PSB_IRQ_ASLE))
dsp_int = 1;
/* FIXME: Handle Medfield
if (vdc_stat & _MDFLD_DISP_ALL_IRQ_FLAG)
dsp_int = 1;
*/
if (vdc_stat & _PSB_IRQ_SGX_FLAG)
sgx_int = 1;
if (vdc_stat & _PSB_IRQ_DISP_HOTSYNC)
hotplug_int = 1;
vdc_stat &= dev_priv->vdc_irq_mask;
spin_unlock(&dev_priv->irqmask_lock);
if (dsp_int && gma_power_is_on(dev)) {
psb_vdc_interrupt(dev, vdc_stat);
handled = 1;
}
if (sgx_int) {
sgx_stat_1 = PSB_RSGX32(PSB_CR_EVENT_STATUS);
sgx_stat_2 = PSB_RSGX32(PSB_CR_EVENT_STATUS2);
psb_sgx_interrupt(dev, sgx_stat_1, sgx_stat_2);
handled = 1;
}
/* Note: this bit has other meanings on some devices, so we will
need to address that later if it ever matters */
if (hotplug_int && dev_priv->ops->hotplug) {
handled = dev_priv->ops->hotplug(dev);
REG_WRITE(PORT_HOTPLUG_STAT, REG_READ(PORT_HOTPLUG_STAT));
}
PSB_WVDC32(vdc_stat, PSB_INT_IDENTITY_R);
(void) PSB_RVDC32(PSB_INT_IDENTITY_R);
rmb();
if (!handled)
return IRQ_NONE;
return IRQ_HANDLED;
}
void psb_irq_preinstall(struct drm_device *dev)
{
struct drm_psb_private *dev_priv =
(struct drm_psb_private *) dev->dev_private;
unsigned long irqflags;
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
if (gma_power_is_on(dev)) {
PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM);
PSB_WVDC32(0x00000000, PSB_INT_MASK_R);
PSB_WVDC32(0x00000000, PSB_INT_ENABLE_R);
PSB_WSGX32(0x00000000, PSB_CR_EVENT_HOST_ENABLE);
PSB_RSGX32(PSB_CR_EVENT_HOST_ENABLE);
}
if (dev->vblank[0].enabled)
dev_priv->vdc_irq_mask |= _PSB_VSYNC_PIPEA_FLAG;
if (dev->vblank[1].enabled)
dev_priv->vdc_irq_mask |= _PSB_VSYNC_PIPEB_FLAG;
/* FIXME: Handle Medfield irq mask
if (dev->vblank[1].enabled)
dev_priv->vdc_irq_mask |= _MDFLD_PIPEB_EVENT_FLAG;
if (dev->vblank[2].enabled)
dev_priv->vdc_irq_mask |= _MDFLD_PIPEC_EVENT_FLAG;
*/
/* Revisit this area - want per device masks ? */
if (dev_priv->ops->hotplug)
dev_priv->vdc_irq_mask |= _PSB_IRQ_DISP_HOTSYNC;
dev_priv->vdc_irq_mask |= _PSB_IRQ_ASLE | _PSB_IRQ_SGX_FLAG;
/* This register is safe even if display island is off */
PSB_WVDC32(~dev_priv->vdc_irq_mask, PSB_INT_MASK_R);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
}
int psb_irq_postinstall(struct drm_device *dev)
{
struct drm_psb_private *dev_priv = dev->dev_private;
unsigned long irqflags;
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
/* Enable 2D and MMU fault interrupts */
PSB_WSGX32(_PSB_CE2_BIF_REQUESTER_FAULT, PSB_CR_EVENT_HOST_ENABLE2);
PSB_WSGX32(_PSB_CE_TWOD_COMPLETE, PSB_CR_EVENT_HOST_ENABLE);
PSB_RSGX32(PSB_CR_EVENT_HOST_ENABLE); /* Post */
/* This register is safe even if display island is off */
PSB_WVDC32(dev_priv->vdc_irq_mask, PSB_INT_ENABLE_R);
PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM);
if (dev->vblank[0].enabled)
psb_enable_pipestat(dev_priv, 0, PIPE_VBLANK_INTERRUPT_ENABLE);
else
psb_disable_pipestat(dev_priv, 0, PIPE_VBLANK_INTERRUPT_ENABLE);
if (dev->vblank[1].enabled)
psb_enable_pipestat(dev_priv, 1, PIPE_VBLANK_INTERRUPT_ENABLE);
else
psb_disable_pipestat(dev_priv, 1, PIPE_VBLANK_INTERRUPT_ENABLE);
if (dev->vblank[2].enabled)
psb_enable_pipestat(dev_priv, 2, PIPE_VBLANK_INTERRUPT_ENABLE);
else
psb_disable_pipestat(dev_priv, 2, PIPE_VBLANK_INTERRUPT_ENABLE);
if (dev_priv->ops->hotplug_enable)
dev_priv->ops->hotplug_enable(dev, true);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
return 0;
}
void psb_irq_uninstall(struct drm_device *dev)
{
struct drm_psb_private *dev_priv = dev->dev_private;
unsigned long irqflags;
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
if (dev_priv->ops->hotplug_enable)
dev_priv->ops->hotplug_enable(dev, false);
PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM);
if (dev->vblank[0].enabled)
psb_disable_pipestat(dev_priv, 0, PIPE_VBLANK_INTERRUPT_ENABLE);
if (dev->vblank[1].enabled)
psb_disable_pipestat(dev_priv, 1, PIPE_VBLANK_INTERRUPT_ENABLE);
if (dev->vblank[2].enabled)
psb_disable_pipestat(dev_priv, 2, PIPE_VBLANK_INTERRUPT_ENABLE);
dev_priv->vdc_irq_mask &= _PSB_IRQ_SGX_FLAG |
_PSB_IRQ_MSVDX_FLAG |
_LNC_IRQ_TOPAZ_FLAG;
/* These two registers are safe even if display island is off */
PSB_WVDC32(~dev_priv->vdc_irq_mask, PSB_INT_MASK_R);
PSB_WVDC32(dev_priv->vdc_irq_mask, PSB_INT_ENABLE_R);
wmb();
/* This register is safe even if display island is off */
PSB_WVDC32(PSB_RVDC32(PSB_INT_IDENTITY_R), PSB_INT_IDENTITY_R);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
}
void psb_irq_turn_on_dpst(struct drm_device *dev)
{
struct drm_psb_private *dev_priv =
(struct drm_psb_private *) dev->dev_private;
u32 hist_reg;
u32 pwm_reg;
if (gma_power_begin(dev, false)) {
PSB_WVDC32(1 << 31, HISTOGRAM_LOGIC_CONTROL);
hist_reg = PSB_RVDC32(HISTOGRAM_LOGIC_CONTROL);
PSB_WVDC32(1 << 31, HISTOGRAM_INT_CONTROL);
hist_reg = PSB_RVDC32(HISTOGRAM_INT_CONTROL);
PSB_WVDC32(0x80010100, PWM_CONTROL_LOGIC);
pwm_reg = PSB_RVDC32(PWM_CONTROL_LOGIC);
PSB_WVDC32(pwm_reg | PWM_PHASEIN_ENABLE
| PWM_PHASEIN_INT_ENABLE,
PWM_CONTROL_LOGIC);
pwm_reg = PSB_RVDC32(PWM_CONTROL_LOGIC);
psb_enable_pipestat(dev_priv, 0, PIPE_DPST_EVENT_ENABLE);
hist_reg = PSB_RVDC32(HISTOGRAM_INT_CONTROL);
PSB_WVDC32(hist_reg | HISTOGRAM_INT_CTRL_CLEAR,
HISTOGRAM_INT_CONTROL);
pwm_reg = PSB_RVDC32(PWM_CONTROL_LOGIC);
PSB_WVDC32(pwm_reg | 0x80010100 | PWM_PHASEIN_ENABLE,
PWM_CONTROL_LOGIC);
gma_power_end(dev);
}
}
int psb_irq_enable_dpst(struct drm_device *dev)
{
struct drm_psb_private *dev_priv =
(struct drm_psb_private *) dev->dev_private;
unsigned long irqflags;
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
/* enable DPST */
mid_enable_pipe_event(dev_priv, 0);
psb_irq_turn_on_dpst(dev);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
return 0;
}
void psb_irq_turn_off_dpst(struct drm_device *dev)
{
struct drm_psb_private *dev_priv =
(struct drm_psb_private *) dev->dev_private;
u32 hist_reg;
u32 pwm_reg;
if (gma_power_begin(dev, false)) {
PSB_WVDC32(0x00000000, HISTOGRAM_INT_CONTROL);
hist_reg = PSB_RVDC32(HISTOGRAM_INT_CONTROL);
psb_disable_pipestat(dev_priv, 0, PIPE_DPST_EVENT_ENABLE);
pwm_reg = PSB_RVDC32(PWM_CONTROL_LOGIC);
PSB_WVDC32(pwm_reg & ~PWM_PHASEIN_INT_ENABLE,
PWM_CONTROL_LOGIC);
pwm_reg = PSB_RVDC32(PWM_CONTROL_LOGIC);
gma_power_end(dev);
}
}
int psb_irq_disable_dpst(struct drm_device *dev)
{
struct drm_psb_private *dev_priv =
(struct drm_psb_private *) dev->dev_private;
unsigned long irqflags;
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
mid_disable_pipe_event(dev_priv, 0);
psb_irq_turn_off_dpst(dev);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
return 0;
}
/*
* It is used to enable VBLANK interrupt
*/
int psb_enable_vblank(struct drm_device *dev, unsigned int pipe)
{
struct drm_psb_private *dev_priv = dev->dev_private;
unsigned long irqflags;
uint32_t reg_val = 0;
uint32_t pipeconf_reg = mid_pipeconf(pipe);
/* Medfield is different - we should perhaps extract out vblank
and blacklight etc ops */
if (IS_MFLD(dev))
return mdfld_enable_te(dev, pipe);
if (gma_power_begin(dev, false)) {
reg_val = REG_READ(pipeconf_reg);
gma_power_end(dev);
}
if (!(reg_val & PIPEACONF_ENABLE))
return -EINVAL;
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
if (pipe == 0)
dev_priv->vdc_irq_mask |= _PSB_VSYNC_PIPEA_FLAG;
else if (pipe == 1)
dev_priv->vdc_irq_mask |= _PSB_VSYNC_PIPEB_FLAG;
PSB_WVDC32(~dev_priv->vdc_irq_mask, PSB_INT_MASK_R);
PSB_WVDC32(dev_priv->vdc_irq_mask, PSB_INT_ENABLE_R);
psb_enable_pipestat(dev_priv, pipe, PIPE_VBLANK_INTERRUPT_ENABLE);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
return 0;
}
/*
* It is used to disable VBLANK interrupt
*/
void psb_disable_vblank(struct drm_device *dev, unsigned int pipe)
{
struct drm_psb_private *dev_priv = dev->dev_private;
unsigned long irqflags;
if (IS_MFLD(dev))
mdfld_disable_te(dev, pipe);
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
if (pipe == 0)
dev_priv->vdc_irq_mask &= ~_PSB_VSYNC_PIPEA_FLAG;
else if (pipe == 1)
dev_priv->vdc_irq_mask &= ~_PSB_VSYNC_PIPEB_FLAG;
PSB_WVDC32(~dev_priv->vdc_irq_mask, PSB_INT_MASK_R);
PSB_WVDC32(dev_priv->vdc_irq_mask, PSB_INT_ENABLE_R);
psb_disable_pipestat(dev_priv, pipe, PIPE_VBLANK_INTERRUPT_ENABLE);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
}
/*
* It is used to enable TE interrupt
*/
int mdfld_enable_te(struct drm_device *dev, int pipe)
{
struct drm_psb_private *dev_priv =
(struct drm_psb_private *) dev->dev_private;
unsigned long irqflags;
uint32_t reg_val = 0;
uint32_t pipeconf_reg = mid_pipeconf(pipe);
if (gma_power_begin(dev, false)) {
reg_val = REG_READ(pipeconf_reg);
gma_power_end(dev);
}
if (!(reg_val & PIPEACONF_ENABLE))
return -EINVAL;
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
mid_enable_pipe_event(dev_priv, pipe);
psb_enable_pipestat(dev_priv, pipe, PIPE_TE_ENABLE);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
return 0;
}
/*
* It is used to disable TE interrupt
*/
void mdfld_disable_te(struct drm_device *dev, int pipe)
{
struct drm_psb_private *dev_priv =
(struct drm_psb_private *) dev->dev_private;
unsigned long irqflags;
if (!dev_priv->dsr_enable)
return;
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
mid_disable_pipe_event(dev_priv, pipe);
psb_disable_pipestat(dev_priv, pipe, PIPE_TE_ENABLE);
spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
}
/* Called from drm generic code, passed a 'crtc', which
* we use as a pipe index
*/
u32 psb_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
{
uint32_t high_frame = PIPEAFRAMEHIGH;
uint32_t low_frame = PIPEAFRAMEPIXEL;
uint32_t pipeconf_reg = PIPEACONF;
uint32_t reg_val = 0;
uint32_t high1 = 0, high2 = 0, low = 0, count = 0;
switch (pipe) {
case 0:
break;
case 1:
high_frame = PIPEBFRAMEHIGH;
low_frame = PIPEBFRAMEPIXEL;
pipeconf_reg = PIPEBCONF;
break;
case 2:
high_frame = PIPECFRAMEHIGH;
low_frame = PIPECFRAMEPIXEL;
pipeconf_reg = PIPECCONF;
break;
default:
dev_err(dev->dev, "%s, invalid pipe.\n", __func__);
return 0;
}
if (!gma_power_begin(dev, false))
return 0;
reg_val = REG_READ(pipeconf_reg);
if (!(reg_val & PIPEACONF_ENABLE)) {
dev_err(dev->dev, "trying to get vblank count for disabled pipe %u\n",
pipe);
goto psb_get_vblank_counter_exit;
}
/*
* High & low register fields aren't synchronized, so make sure
* we get a low value that's stable across two reads of the high
* register.
*/
do {
high1 = ((REG_READ(high_frame) & PIPE_FRAME_HIGH_MASK) >>
PIPE_FRAME_HIGH_SHIFT);
low = ((REG_READ(low_frame) & PIPE_FRAME_LOW_MASK) >>
PIPE_FRAME_LOW_SHIFT);
high2 = ((REG_READ(high_frame) & PIPE_FRAME_HIGH_MASK) >>
PIPE_FRAME_HIGH_SHIFT);
} while (high1 != high2);
count = (high1 << 8) | low;
psb_get_vblank_counter_exit:
gma_power_end(dev);
return count;
}
