[Intel-gfx] [PATCH 2/2] drm/i915: CABC support for backlight control

Deepak, M m.deepak at intel.com
Thu Mar 24 10:03:08 UTC 2016



> -----Original Message-----
> From: Nikula, Jani
> Sent: Thursday, March 24, 2016 3:11 PM
> To: Deepak, M <m.deepak at intel.com>; intel-gfx at lists.freedesktop.org
> Cc: Deepak, M <m.deepak at intel.com>; Vetter, Daniel
> <daniel.vetter at intel.com>; Adebisi, YetundeX
> <yetundex.adebisi at intel.com>
> Subject: Re: [PATCH 2/2] drm/i915: CABC support for backlight control
> 
> On Thu, 24 Mar 2016, Deepak M <m.deepak at intel.com> wrote:
> > [ text/plain ]
> > In CABC (Content Adaptive Brightness Control) content grey level scale
> > can be increased while simultaneously decreasing brightness of the
> > backlight to achieve same perceived brightness.
> >
> > The CABC is not standardized and panel vendors are free to follow
> > their implementation. The CABC implementaion here assumes that the
> > panels use standard SW register for control.
> >
> > In this design there will be no PWM signal from the SoC and DCS
> > commands are sent to enable and control the backlight brightness.
> >
> > v2: Moving the CABC bkl functions to new file.(Jani)
> >
> > v3: Rebase
> >
> > v4: Rebase
> >
> > v5: Use mipi_dsi_dcs_write() instead of mipi_dsi_dcs_write_buffer() (Jani)
> >     Move DCS macro`s to include/video/mipi_display.h (Jani)
> 
> Where's the patch actually adding the macros? We need that in the same
> series to have CI actually build and run this; this fails without them.
> 
> BR,
> Jani.
> 
> 
[Deepak, M] Okay will resend these patches including that patch also.
> >
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Cc: Daniel Vetter <daniel.vetter at intel.com>
> > Cc: Yetunde Adebisi <yetundex.adebisi at intel.com>
> > Signed-off-by: Deepak M <m.deepak at intel.com>
> > ---
> >
> > The DCS command macro`s are defined in the patch which is posted in
> > the dri-devel list.
> >
> >  drivers/gpu/drm/i915/Makefile         |   1 +
> >  drivers/gpu/drm/i915/i915_drv.h       |   1 -
> >  drivers/gpu/drm/i915/intel_drv.h      |   2 +
> >  drivers/gpu/drm/i915/intel_dsi.c      |  19 ++++-
> >  drivers/gpu/drm/i915/intel_dsi.h      |   4 +
> >  drivers/gpu/drm/i915/intel_dsi_cabc.c | 154
> ++++++++++++++++++++++++++++++++++
> >  drivers/gpu/drm/i915/intel_panel.c    |   4 +
> >  7 files changed, 182 insertions(+), 3 deletions(-)  create mode
> > 100644 drivers/gpu/drm/i915/intel_dsi_cabc.c
> >
> > diff --git a/drivers/gpu/drm/i915/Makefile
> > b/drivers/gpu/drm/i915/Makefile index 7ffb51b..065c410 100644
> > --- a/drivers/gpu/drm/i915/Makefile
> > +++ b/drivers/gpu/drm/i915/Makefile
> > @@ -83,6 +83,7 @@ i915-y += dvo_ch7017.o \
> >  	  intel_dp_mst.o \
> >  	  intel_dp.o \
> >  	  intel_dsi.o \
> > +	  intel_dsi_cabc.o \
> >  	  intel_dsi_panel_vbt.o \
> >  	  intel_dsi_pll.o \
> >  	  intel_dvo.o \
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h index 050d860..9ed60f8 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -3489,7 +3489,6 @@ void intel_sbi_write(struct drm_i915_private
> *dev_priv, u16 reg, u32 value,
> >  		     enum intel_sbi_destination destination);
> >  u32 vlv_flisdsi_read(struct drm_i915_private *dev_priv, u32 reg);
> > void vlv_flisdsi_write(struct drm_i915_private *dev_priv, u32 reg, u32
> > val);
> > -
> >  int intel_gpu_freq(struct drm_i915_private *dev_priv, int val);  int
> > intel_freq_opcode(struct drm_i915_private *dev_priv, int val);
> >
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > b/drivers/gpu/drm/i915/intel_drv.h
> > index c87b450..9e49396 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1325,6 +1325,8 @@ void intel_dp_mst_encoder_cleanup(struct
> > intel_digital_port *intel_dig_port);
> >  /* intel_dsi.c */
> >  void intel_dsi_init(struct drm_device *dev);
> >
> > +/* intel_dsi_cabc.c */
> > +int intel_dsi_cabc_init_backlight_funcs(struct intel_connector
> > +*intel_connector);
> >
> >  /* intel_dvo.c */
> >  void intel_dvo_init(struct drm_device *dev); diff --git
> > a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> > index 456676c..7aa707f 100644
> > --- a/drivers/gpu/drm/i915/intel_dsi.c
> > +++ b/drivers/gpu/drm/i915/intel_dsi.c
> > @@ -1209,10 +1209,25 @@ void intel_dsi_init(struct drm_device *dev)
> >  	else
> >  		intel_encoder->crtc_mask = BIT(PIPE_B);
> >
> > -	if (dev_priv->vbt.dsi.config->dual_link)
> > +	if (dev_priv->vbt.dsi.config->dual_link) {
> >  		intel_dsi->ports = BIT(PORT_A) | BIT(PORT_C);
> > -	else
> > +		switch (dev_priv->vbt.dsi.config->dl_cabc_port) {
> > +		case CABC_PORT_A:
> > +			intel_dsi->bkl_dcs_ports = BIT(PORT_A);
> > +			break;
> > +		case CABC_PORT_C:
> > +			intel_dsi->bkl_dcs_ports = BIT(PORT_C);
> > +			break;
> > +		case CABC_PORT_A_AND_C:
> > +			intel_dsi->bkl_dcs_ports = BIT(PORT_A) |
> BIT(PORT_C);
> > +			break;
> > +		default:
> > +			DRM_ERROR("Unknown MIPI ports for sending
> DCS\n");
> > +		}
> > +	} else {
> >  		intel_dsi->ports = BIT(port);
> > +		intel_dsi->bkl_dcs_ports = BIT(port);
> > +	}
> >
> >  	/* Create a DSI host (and a device) for each port. */
> >  	for_each_dsi_port(port, intel_dsi->ports) { diff --git
> > a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h
> > index 0e758f1..5c07d59 100644
> > --- a/drivers/gpu/drm/i915/intel_dsi.h
> > +++ b/drivers/gpu/drm/i915/intel_dsi.h
> > @@ -34,6 +34,10 @@
> >  #define DSI_DUAL_LINK_FRONT_BACK	1
> >  #define DSI_DUAL_LINK_PIXEL_ALT		2
> >
> > +#define CABC_PORT_A                     0x00
> > +#define CABC_PORT_C                     0x01
> > +#define CABC_PORT_A_AND_C               0x02
> > +
> >  struct intel_dsi_host;
> >
> >  struct intel_dsi {
> > diff --git a/drivers/gpu/drm/i915/intel_dsi_cabc.c
> > b/drivers/gpu/drm/i915/intel_dsi_cabc.c
> > new file mode 100644
> > index 0000000..230ee4f
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/intel_dsi_cabc.c
> > @@ -0,0 +1,154 @@
> > +/*
> > + * Copyright © 2016 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.
> > + *
> > + * Author: Deepak M <m.deepak at intel.com>  */
> > +
> > +#include "intel_drv.h"
> > +#include "intel_dsi.h"
> > +#include "i915_drv.h"
> > +#include <video/mipi_display.h>
> > +#include <drm/drm_mipi_dsi.h>
> > +
> > +#define CABC_OFF                        (0 << 0)
> > +#define CABC_USER_INTERFACE_IMAGE       (1 << 0)
> > +#define CABC_STILL_PICTURE              (2 << 0)
> > +#define CABC_VIDEO_MODE                 (3 << 0)
> > +
> > +#define CABC_BACKLIGHT                  (1 << 2)
> > +#define CABC_DIMMING_DISPLAY            (1 << 3)
> > +#define CABC_BCTRL                      (1 << 5)
> > +
> > +#define CABC_MAX_VALUE                  0xFF
> > +
> > +static u32 cabc_get_backlight(struct intel_connector *connector) {
> > +	struct intel_encoder *encoder = connector->encoder;
> > +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +	struct mipi_dsi_device *dsi_device;
> > +	u8 data[2] = {0};
> > +	enum port port;
> > +
> > +	for_each_dsi_port(port, intel_dsi->bkl_dcs_ports) {
> > +		dsi_device = intel_dsi->dsi_hosts[port]->device;
> > +		mipi_dsi_dcs_read(dsi_device,
> MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
> > +					data, 2);
> > +	}
> > +
> > +	return data[1];
> > +}
> > +
> > +static void cabc_set_backlight(struct intel_connector *connector, u32
> > +level) {
> > +	struct intel_encoder *encoder = connector->encoder;
> > +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +	struct mipi_dsi_device *dsi_device;
> > +	u8 data = 0;
> > +	enum port port;
> > +
> > +	for_each_dsi_port(port, intel_dsi->bkl_dcs_ports) {
> > +		dsi_device = intel_dsi->dsi_hosts[port]->device;
> > +		data = level;
> > +		mipi_dsi_dcs_write(dsi_device,
> MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
> > +					&data, sizeof(data));
> > +	}
> > +}
> > +
> > +static void cabc_disable_backlight(struct intel_connector *connector)
> > +{
> > +	struct intel_encoder *encoder = connector->encoder;
> > +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +	struct mipi_dsi_device *dsi_device;
> > +	enum port port;
> > +	u8 data = 0;
> > +
> > +	cabc_set_backlight(connector, 0);
> > +
> > +	for_each_dsi_port(port, intel_dsi->bkl_dcs_ports) {
> > +		dsi_device = intel_dsi->dsi_hosts[port]->device;
> > +		data = CABC_OFF;
> > +		mipi_dsi_dcs_write(dsi_device,
> MIPI_DCS_WRITE_POWER_SAVE,
> > +					&data, sizeof(data));
> > +		mipi_dsi_dcs_write(dsi_device,
> MIPI_DCS_WRITE_CONTROL_DISPLAY,
> > +					&data, sizeof(data));
> > +	}
> > +}
> > +
> > +static void cabc_enable_backlight(struct intel_connector *connector)
> > +{
> > +	struct intel_encoder *encoder = connector->encoder;
> > +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +	struct intel_panel *panel = &connector->panel;
> > +	struct mipi_dsi_device *dsi_device;
> > +	enum port port;
> > +	u8 data = 0;
> > +
> > +	for_each_dsi_port(port, intel_dsi->bkl_dcs_ports) {
> > +		dsi_device = intel_dsi->dsi_hosts[port]->device;
> > +		data = CABC_BACKLIGHT | CABC_DIMMING_DISPLAY |
> CABC_BCTRL;
> > +		mipi_dsi_dcs_write(dsi_device,
> MIPI_DCS_WRITE_CONTROL_DISPLAY,
> > +					&data, sizeof(data));
> > +		data = CABC_STILL_PICTURE;
> > +		mipi_dsi_dcs_write(dsi_device,
> MIPI_DCS_WRITE_POWER_SAVE,
> > +					&data, sizeof(data));
> > +	}
> > +
> > +	cabc_set_backlight(connector, panel->backlight.level); }
> > +
> > +static int cabc_setup_backlight(struct intel_connector *connector,
> > +		enum pipe unused)
> > +{
> > +	struct intel_panel *panel = &connector->panel;
> > +
> > +	panel->backlight.max = CABC_MAX_VALUE;
> > +	panel->backlight.level = CABC_MAX_VALUE;
> > +
> > +	return 0;
> > +}
> > +
> > +int intel_dsi_cabc_init_backlight_funcs(struct intel_connector
> > +*intel_connector) {
> > +	struct drm_device *dev = intel_connector->base.dev;
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	struct intel_encoder *encoder = intel_connector->encoder;
> > +	struct intel_panel *panel = &intel_connector->panel;
> > +
> > +	if (!dev_priv->vbt.dsi.config->cabc_supported)
> > +		return -ENODEV;
> > +
> > +	if (encoder->type != INTEL_OUTPUT_DSI) {
> > +		DRM_ERROR("Use DSI encoder for CABC\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (WARN_ON(encoder->type != INTEL_OUTPUT_DSI))
> > +		return -EINVAL;
> > +
> > +	panel->backlight.setup = cabc_setup_backlight;
> > +	panel->backlight.enable = cabc_enable_backlight;
> > +	panel->backlight.disable = cabc_disable_backlight;
> > +	panel->backlight.set = cabc_set_backlight;
> > +	panel->backlight.get = cabc_get_backlight;
> > +
> > +	return 0;
> > +}
> > diff --git a/drivers/gpu/drm/i915/intel_panel.c
> > b/drivers/gpu/drm/i915/intel_panel.c
> > index 8c8996f..641c38f 100644
> > --- a/drivers/gpu/drm/i915/intel_panel.c
> > +++ b/drivers/gpu/drm/i915/intel_panel.c
> > @@ -1718,6 +1718,10 @@ intel_panel_init_backlight_funcs(struct
> intel_panel *panel)
> >  		container_of(panel, struct intel_connector, panel);
> >  	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
> >
> > +	if (connector->base.connector_type ==
> DRM_MODE_CONNECTOR_DSI &&
> > +		intel_dsi_cabc_init_backlight_funcs(connector) == 0)
> > +		return;
> > +
> >  	if (IS_BROXTON(dev_priv)) {
> >  		panel->backlight.setup = bxt_setup_backlight;
> >  		panel->backlight.enable = bxt_enable_backlight;
> 
> --
> Jani Nikula, Intel Open Source Technology Center


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