[PATCHv2 1/5] drm/i915/display: Add support for histogram

Murthy, Arun R arun.r.murthy at intel.com
Sun Sep 15 04:59:50 UTC 2024


> > pipe's current pixel count.
> > +#define HISTOGRAM_GUARDBAND_PRECISION_FACTOR 10000   // Precision
> > factor for threshold guardband.
> > +#define HISTOGRAM_DEFAULT_GUARDBAND_DELAY 0x04
> > +
> > +struct intel_histogram {
> > +	struct drm_i915_private *i915;
> 
> Lets use intel_display here instead of i915 as I can see this is mostly being used
> for reg read/writes Read/write/rmw also work with intel_display well.
> 
Sure!

> > +	bool enable;
> > +	bool can_enable;
> > +	enum pipe pipe;
> > +	u32 bindata[HISTOGRAM_BIN_COUNT];
> > +};
> > +
> > +int intel_histogram_atomic_check(struct intel_crtc *intel_crtc) {
> > +	struct intel_histogram *histogram = intel_crtc->histogram;
> > +
> > +	/* TODO: Restrictions for enabling histogram */
> > +	histogram->can_enable = true;
> > +
> > +	return 0;
> > +}
> > +
> > +static void intel_histogram_enable_dithering(struct drm_i915_private
> > *dev_priv,
> 
> Use intel_display here
Done

> > +					     enum pipe pipe)
> > +{
> > +	intel_de_rmw(dev_priv, PIPE_MISC(pipe), PIPE_MISC_DITHER_ENABLE,
> > +		     PIPE_MISC_DITHER_ENABLE);
> 
> So every where below drm_i915_private can be replaced with intel_display
> Ditto.
> 
Done
> > +}
> > +
> > +static int intel_histogram_enable(struct intel_crtc *intel_crtc) {
> > +	struct drm_i915_private *i915 = to_i915(intel_crtc->base.dev);
> > +	struct intel_histogram *histogram = intel_crtc->histogram;
> > +	int pipe = intel_crtc->pipe;
> > +	u64 res;
> > +	u32 gbandthreshold;
> > +
> > +	if (!histogram)
> > +		return -EINVAL;
> > +
> > +	if (!histogram->can_enable) {
> > +		return -EINVAL;
> > +	}
> 
> No need for brackets here now atleast
> 
Done

> > +
> > +	if (histogram->enable)
> > +		return 0;
> > +
> > +	/* Pipe Dithering should be enabled with GLOBAL_HIST */
> > +	intel_histogram_enable_dithering(i915, pipe);
> > +
> > +	/*
> > +	 * enable DPST_CTL Histogram mode
> > +	 * Clear DPST_CTL Bin Reg function select to TC
> > +	 */
> 
> Nit: maybe make it Enable DPST... and If we are mentioning the steps lets add
> some number or points(-)
> 
Done

> > +	intel_de_rmw(i915, DPST_CTL(pipe),
> > +		     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_IE_HIST_EN |
> > +		     DPST_CTL_HIST_MODE |
> > DPST_CTL_IE_TABLE_VALUE_FORMAT,
> > +		     DPST_CTL_BIN_REG_FUNC_TC | DPST_CTL_IE_HIST_EN |
> > +		     DPST_CTL_HIST_MODE_HSV |
> > +		     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC);
> > +
> > +	/* Re-Visit: check if wait for one vblank is required */
> > +	drm_crtc_wait_one_vblank(&intel_crtc->base);
> > +
> > +	/* TODO: one time programming: Program GuardBand Threshold */
> > +	res = (intel_crtc->config->hw.adjusted_mode.vtotal *
> > +				intel_crtc->config->hw.adjusted_mode.htotal);
> > +	gbandthreshold = (res *
> > 	HISTOGRAM_GUARDBAND_THRESHOLD_DEFAULT) /
> > +
> > 	HISTOGRAM_GUARDBAND_PRECISION_FACTOR;
> > +
> > +	/* Enable histogram interrupt mode */
> > +	intel_de_rmw(i915, DPST_GUARD(pipe),
> > +		     DPST_GUARD_THRESHOLD_GB_MASK |
> > +		     DPST_GUARD_INTERRUPT_DELAY_MASK |
> > DPST_GUARD_HIST_INT_EN,
> > +		     DPST_GUARD_THRESHOLD_GB(gbandthreshold) |
> > +
> >
> DPST_GUARD_INTERRUPT_DELAY(HISTOGRAM_DEFAULT_GUARDBAND_DELAY)
> > |
> > +		     DPST_GUARD_HIST_INT_EN);
> > +
> > +	/* Clear pending interrupts has to be done on separate write */
> > +	intel_de_rmw(i915, DPST_GUARD(pipe),
> > +		     DPST_GUARD_HIST_EVENT_STATUS, 1);
> > +
> > +	histogram->enable = true;
> > +
> > +	return 0;
> > +}
> > +
> > +static void intel_histogram_disable(struct intel_crtc *intel_crtc) {
> > +	struct drm_i915_private *i915 = to_i915(intel_crtc->base.dev);
> > +	struct intel_histogram *histogram = intel_crtc->histogram;
> > +	int pipe = intel_crtc->pipe;
> > +
> > +	if (!histogram)
> > +		return;
> > +
> > +	/* Pipe Dithering should be enabled with GLOBAL_HIST */
> > +	intel_histogram_enable_dithering(i915, pipe);
> > +
> > +	/* Clear pending interrupts and disable interrupts */
> > +	intel_de_rmw(i915, DPST_GUARD(pipe),
> > +		     DPST_GUARD_HIST_INT_EN |
> > DPST_GUARD_HIST_EVENT_STATUS, 0);
> > +
> > +	/* disable DPST_CTL Histogram mode */
> > +	intel_de_rmw(i915, DPST_CTL(pipe),
> > +		     DPST_CTL_IE_HIST_EN, 0);
> > +
> > +	histogram->enable = false;
> > +}
> > +
> > +int intel_histogram_update(struct intel_crtc *intel_crtc, bool
> > +enable) {
> > +	if (enable)
> > +		return intel_histogram_enable(intel_crtc);
> > +
> > +	intel_histogram_disable(intel_crtc);
> > +	return 0;
> > +}
> > +
> > +int intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32
> > +*data) {
> > +	struct intel_histogram *histogram = intel_crtc->histogram;
> > +	struct drm_i915_private *i915 = to_i915(intel_crtc->base.dev);
> > +	int pipe = intel_crtc->pipe;
> > +	int i = 0;
> > +
> > +	if (!histogram)
> > +		return -EINVAL;
> > +
> > +	if (!histogram->enable) {
> > +		drm_err(&i915->drm, "histogram not enabled");
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (!data) {
> > +		drm_err(&i915->drm, "enhancement LUT data is NULL");
> > +		return -EINVAL;
> > +	}
> > +
> > +	/*
> > +	 * Set DPST_CTL Bin Reg function select to IE
> > +	 * Set DPST_CTL Bin Register Index to 0
> > +	 */
> > +	intel_de_rmw(i915, DPST_CTL(pipe),
> > +		     DPST_CTL_BIN_REG_FUNC_SEL |
> DPST_CTL_BIN_REG_MASK,
> > +		     DPST_CTL_BIN_REG_FUNC_IE |
> DPST_CTL_BIN_REG_CLEAR);
> > +
> > +	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
> > +		intel_de_rmw(i915, DPST_BIN(pipe),
> > +			     DPST_BIN_DATA_MASK, data[i]);
> > +		drm_dbg_atomic(&i915->drm, "iet_lut[%d]=%x\n", i, data[i]);
> > +	}
> > +
> > +	intel_de_rmw(i915, DPST_CTL(pipe),
> > +		     DPST_CTL_ENHANCEMENT_MODE_MASK |
> > DPST_CTL_IE_MODI_TABLE_EN,
> > +		     DPST_CTL_EN_MULTIPLICATIVE |
> > DPST_CTL_IE_MODI_TABLE_EN);
> > +
> > +	/* Once IE is applied, change DPST CTL to TC */
> > +	intel_de_rmw(i915, DPST_CTL(pipe),
> > +		     DPST_CTL_BIN_REG_FUNC_SEL,
> > DPST_CTL_BIN_REG_FUNC_TC);
> > +
> > +	return 0;
> > +}
> > +
> > +void intel_histogram_deinit(struct intel_crtc *intel_crtc) {
> > +	struct intel_histogram *histogram = intel_crtc->histogram;
> > +
> > +	kfree(histogram);
> > +}
> > +
> > +int intel_histogram_init(struct intel_crtc *intel_crtc) {
> > +	struct drm_i915_private *i915 = to_i915(intel_crtc->base.dev);
> > +	struct intel_histogram *histogram;
> > +
> > +	/* Allocate histogram internal struct */
> > +	histogram = kzalloc(sizeof(*histogram), GFP_KERNEL);
> > +	if (!histogram) {
> > +		return -ENOMEM;
> > +	}
> > +
> > +	intel_crtc->histogram = histogram;
> > +	histogram->pipe = intel_crtc->pipe;
> > +	histogram->can_enable = false;
> > +
> > +	histogram->i915 = i915;
> > +
> > +	return 0;
> > +}
> > diff --git a/drivers/gpu/drm/i915/display/intel_histogram.h
> > b/drivers/gpu/drm/i915/display/intel_histogram.h
> > new file mode 100644
> > index 000000000000..b25091732274
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/display/intel_histogram.h
> > @@ -0,0 +1,78 @@
> > +// SPDX-License-Identifier: MIT
> > +/*
> > + * Copyright © 2024 Intel Corporation  */
> > +
> > +#ifndef __INTEL_HISTOGRAM_H__
> > +#define __INTEL_HISTOGRAM_H__
> > +
> > +#include <linux/types.h>
> > +
> > +struct intel_crtc;
> > +
> > +/* GLOBAL_HIST related registers */
> > +#define _DPST_CTL_A					0x490C0
> > +#define _DPST_CTL_B					0x491C0
> > +#define DPST_CTL(pipe)
> > 	_MMIO_PIPE(pipe, _DPST_CTL_A, _DPST_CTL_B)
> > +#define DPST_CTL_IE_HIST_EN				REG_BIT(31)
> > +#define DPST_CTL_RESTORE				REG_BIT(28)
> > +#define DPST_CTL_IE_MODI_TABLE_EN			REG_BIT(27)
> > +#define DPST_CTL_HIST_MODE				REG_BIT(24)
> > +#define DPST_CTL_ENHANCEMENT_MODE_MASK
> > 	REG_GENMASK(14, 13)
> > +#define DPST_CTL_EN_MULTIPLICATIVE
> > 	REG_FIELD_PREP(DPST_CTL_ENHANCEMENT_MODE_MASK, 2)
> > +#define DPST_CTL_IE_TABLE_VALUE_FORMAT			REG_BIT(15)
> > +#define DPST_CTL_BIN_REG_FUNC_SEL			REG_BIT(11)
> > +#define DPST_CTL_BIN_REG_FUNC_TC
> > 	REG_FIELD_PREP(DPST_CTL_BIN_REG_FUNC_SEL, 0)
> > +#define DPST_CTL_BIN_REG_FUNC_IE
> > 	REG_FIELD_PREP(DPST_CTL_BIN_REG_FUNC_SEL, 1)
> > +#define DPST_CTL_BIN_REG_MASK
> > 	REG_GENMASK(6, 0)
> > +#define DPST_CTL_BIN_REG_CLEAR
> > 	REG_FIELD_PREP(DPST_CTL_BIN_REG_MASK, 0)
> > +#define DPST_CTL_IE_TABLE_VALUE_FORMAT_2INT_8FRAC
> > 	REG_FIELD_PREP(DPST_CTL_IE_TABLE_VALUE_FORMAT, 1)
> > +#define DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC
> > 	REG_FIELD_PREP(DPST_CTL_IE_TABLE_VALUE_FORMAT, 0)
> > +#define DPST_CTL_HIST_MODE_YUV
> > 	REG_FIELD_PREP(DPST_CTL_HIST_MODE, 0)
> > +#define DPST_CTL_HIST_MODE_HSV
> > 	REG_FIELD_PREP(DPST_CTL_HIST_MODE, 1)
> > +
> > +#define _DPST_GUARD_A					0x490C8
> > +#define _DPST_GUARD_B					0x491C8
> > +#define DPST_GUARD(pipe)				_MMIO_PIPE(pipe,
> > _DPST_GUARD_A, _DPST_GUARD_B)
> > +#define DPST_GUARD_HIST_INT_EN				REG_BIT(31)
> > +#define DPST_GUARD_HIST_EVENT_STATUS			REG_BIT(30)
> > +#define DPST_GUARD_INTERRUPT_DELAY_MASK
> > 	REG_GENMASK(29, 22)
> > +#define DPST_GUARD_INTERRUPT_DELAY(val)
> > 	REG_FIELD_PREP(DPST_GUARD_INTERRUPT_DELAY_MASK, val)
> > +#define DPST_GUARD_THRESHOLD_GB_MASK
> > 	REG_GENMASK(21, 0)
> > +#define DPST_GUARD_THRESHOLD_GB(val)
> > 	REG_FIELD_PREP(DPST_GUARD_THRESHOLD_GB_MASK, val)
> > +
> > +#define _DPST_BIN_A					0x490C4
> > +#define _DPST_BIN_B					0x491C4
> > +#define DPST_BIN(pipe)
> > 	_MMIO_PIPE(pipe, _DPST_BIN_A, _DPST_BIN_B)
> > +#define DPST_BIN_DATA_MASK
> > 	REG_GENMASK(23, 0)
> > +#define DPST_BIN_BUSY					REG_BIT(31)
> > +
> > +#define INTEL_HISTOGRAM_PIPEA			0x90000000
> > +#define INTEL_HISTOGRAM_PIPEB			0x90000002
> > +#define INTEL_HISTOGRAM_EVENT(pipe)		PIPE(pipe, \
> > +						     INTEL_HISTOGRAM_PIPEA,
> \
> > +						     INTEL_HISTOGRAM_PIPEB)
> 
> I don't think this is the right way. Lets have a file for intel_histogram_regs.h and
> intel_histogram.h That will look a lot cleaner.
> 
Done

> > +
> > +#define HISTOGRAM_BIN_COUNT			32
> > +#define HISTOGRAM_IET_LENGTH			33
> > +
> > +enum intel_global_hist_status {
> > +	INTEL_HISTOGRAM_ENABLE,
> > +	INTEL_HISTOGRAM_DISABLE,
> > +};
> > +
> > +enum intel_global_histogram {
> > +	INTEL_HISTOGRAM,
> > +};
> > +
> > +enum intel_global_hist_lut {
> > +	INTEL_HISTOGRAM_PIXEL_FACTOR,
> > +};
> > +
> > +int intel_histogram_atomic_check(struct intel_crtc *intel_crtc); int
> > +intel_histogram_update(struct intel_crtc *intel_crtc, bool enable);
> > +int intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32
> > +*data); int intel_histogram_init(struct intel_crtc *intel_crtc); void
> > +intel_histogram_deinit(struct intel_crtc *intel_crtc);
> > +
> > +#endif /* __INTEL_HISTOGRAM_H__ */
> > diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> > index b9670ae09a9e..424ea43016dd 100644
> > --- a/drivers/gpu/drm/xe/Makefile
> > +++ b/drivers/gpu/drm/xe/Makefile
> > @@ -238,6 +238,7 @@ xe-$(CONFIG_DRM_XE_DISPLAY) += \
> >  	i915-display/intel_hdcp.o \
> >  	i915-display/intel_hdcp_gsc_message.o \
> >  	i915-display/intel_hdmi.o \
> > +	i915-display/intel_histogram.o \
> >  	i915-display/intel_hotplug.o \
> >  	i915-display/intel_hotplug_irq.o \
> >  	i915-display/intel_hti.o \
> 
> Lets try to separate xe and i915 changes into different patches as well as we can
> I know its tough to decouple some Changes but the ones that can be done
> should be.
> 
Done

Thanks and Regards,
Arun R Murthy
--------------------




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