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)

Cc: Jani Nikula jani.nikula@intel.com Cc: Daniel Vetter daniel.vetter@intel.com Cc: Yetunde Adebisi yetundex.adebisi@intel.com Signed-off-by: Deepak M m.deepak@intel.com --- drivers/gpu/drm/i915/Makefile | 1 + drivers/gpu/drm/i915/i915_drv.h | 2 +- drivers/gpu/drm/i915/intel_dsi.c | 17 +++- 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, 205 insertions(+), 2 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 0851de07..2c69ed4 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -82,6 +82,7 @@ i915-y += dvo_ch7017.o \ intel_dp.o \ intel_dsi.o \ intel_dsi_panel_vbt.o \ + intel_dsi_cabc.o \ intel_dsi_pll.o \ intel_dvo.o \ intel_hdmi.o \ diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 6644c2e..43dd10e 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3488,7 +3488,7 @@ 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); 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 b928c50..caa65df 100644 --- a/drivers/gpu/drm/i915/intel_dsi.c +++ b/drivers/gpu/drm/i915/intel_dsi.c @@ -1171,8 +1171,23 @@ void intel_dsi_init(struct drm_device *dev) intel_dsi->ports = (1 << PORT_C); }

- if (dev_priv->vbt.dsi.config->dual_link) + if (dev_priv->vbt.dsi.config->dual_link) { intel_dsi->ports = ((1 << PORT_A) | (1 << PORT_C)); + switch (dev_priv->vbt.dsi.config->dl_cabc_port) { + case CABC_PORT_A: + intel_dsi->bkl_dcs_ports = (1 << PORT_A); + break; + case CABC_PORT_C: + intel_dsi->bkl_dcs_ports = (1 << PORT_C); + break; + case CABC_PORT_A_AND_C: + intel_dsi->bkl_dcs_ports = intel_dsi->ports; + break; + default: + DRM_ERROR("Unknown MIPI ports for sending DCS\n"); + } + } else + intel_dsi->bkl_dcs_ports = intel_dsi->ports;

/* 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 6dfa0e3..466da2d 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 + * + * 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 + +#define MIPI_DCS_CABC_LEVEL_RD 0x52 +#define MIPI_DCS_CABC_MIN_BRIGHTNESS_RD 0x5F +#define MIPI_DCS_CABC_CONTROL_RD 0x56 +#define MIPI_DCS_CABC_CONTROL_BRIGHT_RD 0x54 +#define MIPI_DCS_CABC_LEVEL_WR 0x51 +#define MIPI_DCS_CABC_MIN_BRIGHTNESS_WR 0x5E +#define MIPI_DCS_CABC_CONTROL_WR 0x55 +#define MIPI_DCS_CABC_CONTROL_BRIGHT_WR 0x53 + +static u32 cabc_get_backlight(struct intel_connector *connector) +{ + 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]; +} + +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); + } +} + +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; + } + + 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; + + if (encoder->type != INTEL_OUTPUT_DSI) { + DRM_ERROR("Use DSI encoder for CABC\n"); + 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 21ee647..f29a8f2 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -1720,6 +1720,10 @@ 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;