[Intel-gfx] [MIPI CABC 2/2] drm/i915: CABC support for backlight control
Jani Nikula
jani.nikula at intel.com
Wed Mar 23 11:51:15 UTC 2016
On Wed, 23 Mar 2016, Jani Nikula <jani.nikula at intel.com> wrote:
> [ text/plain ]
> On Wed, 23 Mar 2016, "Deepak, M" <m.deepak at intel.com> wrote:
>>> -----Original Message-----
>>> From: Nikula, Jani
>>> Sent: Tuesday, March 22, 2016 7:19 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: [MIPI CABC 2/2] drm/i915: CABC support for backlight control
>>>
>>> On Tue, 22 Mar 2016, Deepak M <m.deepak at intel.com> 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 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>
>>> > ---
>>> > 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...
>
> Look at the maximum value to decide? That's what needs to be set in
> setup if the size changes, so no need to add another variable.
Or just ignore this part for now, and go for either 8 or 16 bits, not
this sometimes this sometimes that.
>
> BR,
> Jani.
>
>>> > +}
>>> > +
>>> > +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
--
Jani Nikula, Intel Open Source Technology Center
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