> -----Original Message-----
> From: Nikula, Jani
> Sent: Tuesday, March 22, 2016 7:19 PM
> To: Deepak, M <m.deepak@xxxxxxxxx>; intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Deepak, M <m.deepak@xxxxxxxxx>; Vetter, Daniel
> <daniel.vetter@xxxxxxxxx>; Adebisi, YetundeX
> <yetundex.adebisi@xxxxxxxxx>
> Subject: Re: [MIPI CABC 2/2] drm/i915: CABC support for backlight control
>
> On Tue, 22 Mar 2016, Deepak M <m.deepak@xxxxxxxxx> wrote:
> > 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
> >
> > Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> > Cc: Yetunde Adebisi <yetundex.adebisi@xxxxxxxxx>
> > Signed-off-by: Deepak M <m.deepak@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/Makefile | 1 +
> > drivers/gpu/drm/i915/i915_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 | 179
> ++++++++++++++++++++++++++++++++++
> > drivers/gpu/drm/i915/intel_panel.c | 4 +
> > 6 files changed, 206 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..d196404 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -3489,7 +3489,7 @@ 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_dsi_cabc_init_backlight_funcs(struct intel_connector
> > +*intel_connector);
>
> This probably fits better in intel_drv.h under a /* intel_dsi_cabc.c */
> comment, see the file for examples.
>
> > 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_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..d14a669
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/intel_dsi_cabc.c
> > @@ -0,0 +1,179 @@
> > +/*
> > + * Copyright © 2006-2010 Intel Corporation
>
> 2016
>
> > + *
> > + * 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 <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
> > +
>
> The defines below should be added to the relevant enum in
> include/video/mipi_display.h using the MIPI DCS specification names. I'll
> copy them below. Please create a separate prep patch and send it to dri-
> devel.
>
> > +#define MIPI_DCS_CABC_LEVEL_RD 0x52
>
> MIPI_DCS_GET_DISPLAY_BRIGHTNESS
>
> > +#define MIPI_DCS_CABC_MIN_BRIGHTNESS_RD 0x5F
>
> MIPI_DCS_GET_CABC_MIN_BRIGHTNESS
>
> > +#define MIPI_DCS_CABC_CONTROL_RD 0x56
>
> MIPI_DCS_GET_POWER_SAVE
>
> > +#define MIPI_DCS_CABC_CONTROL_BRIGHT_RD 0x54
>
> MIPI_DCS_GET_CONTROL_DISPLAY
>
> > +#define MIPI_DCS_CABC_LEVEL_WR 0x51
>
> MIPI_DCS_SET_DISPLAY_BRIGHTNESS
>
> > +#define MIPI_DCS_CABC_MIN_BRIGHTNESS_WR 0x5E
>
> MIPI_DCS_SET_CABC_MIN_BRIGHTNESS
>
> > +#define MIPI_DCS_CABC_CONTROL_WR 0x55
>
> MIPI_DCS_WRITE_POWER_SAVE
>
> > +#define MIPI_DCS_CABC_CONTROL_BRIGHT_WR 0x53
>
> MIPI_DCS_WRITE_CONTROL_DISPLAY
>
> > +
> > +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);
>
> Same for all functions below.
>
> > + struct intel_dsi *intel_dsi = NULL;
> > + struct intel_encoder *encoder = NULL;
> > + struct mipi_dsi_device *dsi_device;
> > + u8 data[2] = {0};
> > + enum port port;
> > +
> > + encoder = connector->encoder;
> > + intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +
> > + 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_CABC_LEVEL_RD,
> data, 2);
> > + }
> > +
> > + return data[1];
>
> Hmm, it's up to the manufacturer whether the this is 8 or 16 bits. I guess
> you're just assuming 8 bits? I wonder if this should be more generic wrt 8 vs.
> 16 bits.
>
[Deepak, M] Need to think on how to make it generic wrt 8 vs 16 bits, problem here is to somehow we have to identify the no of parameters or we have to pass this info in VBT...
> > +}
> > +
> > +static void cabc_set_backlight(struct intel_connector *connector, u32
> > +level) {
> > + struct intel_dsi *intel_dsi = NULL;
> > + struct intel_encoder *encoder = NULL;
> > + struct mipi_dsi_device *dsi_device;
> > + u8 data[2] = {0};
> > + enum port port;
> > +
> > + encoder = connector->encoder;
> > + intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +
> > + for_each_dsi_port(port, intel_dsi->bkl_dcs_ports) {
> > + dsi_device = intel_dsi->dsi_hosts[port]->device;
> > + data[1] = level;
> > + data[0] = MIPI_DCS_CABC_LEVEL_WR;
> > + mipi_dsi_dcs_write_buffer(dsi_device, data, 2);
>
> Please use mipi_dsi_dcs_write(). Same for all functions below.
>
> > + }
> > +}
> > +
> > +static void cabc_disable_backlight(struct intel_connector *connector)
> > +{
> > + struct intel_dsi *intel_dsi = NULL;
> > + struct intel_encoder *encoder = NULL;
> > + struct mipi_dsi_device *dsi_device;
> > + enum port port;
> > + u8 data[2] = {0};
> > +
> > + encoder = connector->encoder;
> > + intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +
> > + cabc_set_backlight(connector, 0);
> > +
> > + for_each_dsi_port(port, intel_dsi->bkl_dcs_ports) {
> > + dsi_device = intel_dsi->dsi_hosts[port]->device;
> > + data[1] = CABC_OFF;
> > + data[0] = MIPI_DCS_CABC_CONTROL_WR;
> > + mipi_dsi_dcs_write_buffer(dsi_device, data, 2);
> > + data[0] = MIPI_DCS_CABC_CONTROL_BRIGHT_WR;
> > + mipi_dsi_dcs_write_buffer(dsi_device, data, 2);
> > + }
> > +}
> > +
> > +static void cabc_enable_backlight(struct intel_connector *connector)
> > +{
> > + struct intel_dsi *intel_dsi = NULL;
> > + struct intel_encoder *encoder = NULL;
> > + struct intel_panel *panel = &connector->panel;
> > + struct mipi_dsi_device *dsi_device;
> > + enum port port;
> > + u8 data[2] = {0};
> > +
> > + encoder = connector->encoder;
> > + intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +
> > + for_each_dsi_port(port, intel_dsi->bkl_dcs_ports) {
> > + dsi_device = intel_dsi->dsi_hosts[port]->device;
> > + data[0] = MIPI_DCS_CABC_CONTROL_BRIGHT_WR;
> > + data[1] = CABC_BACKLIGHT | CABC_DIMMING_DISPLAY |
> CABC_BCTRL;
> > + mipi_dsi_dcs_write_buffer(dsi_device, data, 2);
> > + data[0] = MIPI_DCS_CABC_CONTROL_WR;
> > + data[1] = CABC_STILL_PICTURE;
> > + mipi_dsi_dcs_write_buffer(dsi_device, data, 2);
> > + }
> > +
> > + cabc_set_backlight(connector, panel->backlight.level); }
> > +
> > +static int cabc_setup_backlight(struct intel_connector *connector,
> > + enum pipe unused)
> > +{
> > + struct drm_device *dev = connector->base.dev;
> > + struct drm_i915_private *dev_priv = dev->dev_private;
> > + struct intel_panel *panel = &connector->panel;
> > +
> > + if (dev_priv->vbt.backlight.present)
> > + panel->backlight.present = true;
> > + else {
> > + DRM_ERROR("no backlight present per VBT\n");
> > + return 0;
> > + }
>
> None of the above is needed.
>
> dev_priv->vbt.backlight.present is checked higher level in
> intel_panel_setup_backlight(), and panel->backlight.present = true is set
> there as well if this hook returns 0.
>
> > +
> > + 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 -EINVAL;
>
> -ENODEV seems more appropriate.
>
> > +
> > + 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..0f9bf80 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)
>
> Indentation is not quite right.
>
> > + 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
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
