drm/i915/dsi: Add DCS control for Panel PWM

If the source of the backlight PWM is from the
panel then the PWM can be controlled by DCS
command, this patch adds the support to
enable/disbale panel PWM, control backlight level
etc...

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)

v6: Rename the file to intel_dsi_panel_pwm.c
    Removing the CABC operations

v7 by Jani: renames, rebases, etc.

v8 by Jani: s/INTEL_BACKLIGHT_CABC/INTEL_BACKLIGHT_DSI_DCS/

v9 by Jani: rename init function to intel_dsi_dcs_init_backlight_funcs

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>
Reviewed-by: Yetunde Adebisi <yetundex.adebisi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/71238a4b14b8c3a6c04070c789f09f1b4bc00a15.1461676337.git.jani.nikula@intel.com

drivers/gpu/drm/i915/Makefile

@@ -87,6 +87,7 @@ i915-y += dvo_ch7017.o \
 	  intel_dp_mst.o \
 	  intel_dp.o \
 	  intel_dsi.o \
+	  intel_dsi_dcs_backlight.o \
 	  intel_dsi_panel_vbt.o \
 	  intel_dsi_pll.o \
 	  intel_dvo.o \

drivers/gpu/drm/i915/intel_drv.h

@@ -1385,6 +1385,8 @@ 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_dcs_backlight.c */
+int intel_dsi_dcs_init_backlight_funcs(struct intel_connector *intel_connector);
 
 /* intel_dvo.c */
 void intel_dvo_init(struct drm_device *dev);

drivers/gpu/drm/i915/intel_dsi.c

@@ -1474,10 +1474,25 @@ 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_dcs_backlight_ports) {
+		case DL_DCS_PORT_A:
+			intel_dsi->dcs_backlight_ports = BIT(PORT_A);
+			break;
+		case DL_DCS_PORT_C:
+			intel_dsi->dcs_backlight_ports = BIT(PORT_C);
+			break;
+		default:
+		case DL_DCS_PORT_A_AND_C:
+			intel_dsi->dcs_backlight_ports = BIT(PORT_A) | BIT(PORT_C);
+			break;
+		}
+	} else {
 		intel_dsi->ports = BIT(port);
+		intel_dsi->dcs_backlight_ports = BIT(port);
+	}
 
 	/* Create a DSI host (and a device) for each port. */
 	for_each_dsi_port(port, intel_dsi->ports) {

drivers/gpu/drm/i915/intel_dsi.h

@@ -78,6 +78,9 @@ struct intel_dsi {
 
 	u8 escape_clk_div;
 	u8 dual_link;
+
+	u16 dcs_backlight_ports;
+
 	u8 pixel_overlap;
 	u32 port_bits;
 	u32 bw_timer;

drivers/gpu/drm/i915/intel_dsi_dcs_backlight.c

@@ -0,0 +1,157 @@
+/*
+ * 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 CONTROL_DISPLAY_BCTRL		(1 << 5)
+#define CONTROL_DISPLAY_DD		(1 << 3)
+#define CONTROL_DISPLAY_BL		(1 << 2)
+
+#define PANEL_PWM_MAX_VALUE		0xFF
+
+static u32 dcs_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;
+	enum port port;
+
+	/* FIXME: Need to take care of 16 bit brightness level */
+	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
+		dsi_device = intel_dsi->dsi_hosts[port]->device;
+		mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
+				  &data, sizeof(data));
+		break;
+	}
+
+	return data;
+}
+
+static void dcs_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 = level;
+	enum port port;
+
+	/* FIXME: Need to take care of 16 bit brightness level */
+	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
+		dsi_device = intel_dsi->dsi_hosts[port]->device;
+		mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
+				   &data, sizeof(data));
+	}
+}
+
+static void dcs_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;
+
+	dcs_set_backlight(connector, 0);
+
+	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
+		u8 ctrl = 0;
+
+		dsi_device = intel_dsi->dsi_hosts[port]->device;
+
+		mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_CONTROL_DISPLAY,
+				  &ctrl, sizeof(ctrl));
+
+		ctrl &= ~CONTROL_DISPLAY_BL;
+		ctrl &= ~CONTROL_DISPLAY_DD;
+		ctrl &= ~CONTROL_DISPLAY_BCTRL;
+
+		mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+				   &ctrl, sizeof(ctrl));
+	}
+}
+
+static void dcs_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;
+
+	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
+		u8 ctrl = 0;
+
+		dsi_device = intel_dsi->dsi_hosts[port]->device;
+
+		mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_CONTROL_DISPLAY,
+				  &ctrl, sizeof(ctrl));
+
+		ctrl |= CONTROL_DISPLAY_BL;
+		ctrl |= CONTROL_DISPLAY_DD;
+		ctrl |= CONTROL_DISPLAY_BCTRL;
+
+		mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+				   &ctrl, sizeof(ctrl));
+	}
+
+	dcs_set_backlight(connector, panel->backlight.level);
+}
+
+static int dcs_setup_backlight(struct intel_connector *connector,
+			       enum pipe unused)
+{
+	struct intel_panel *panel = &connector->panel;
+
+	panel->backlight.max = PANEL_PWM_MAX_VALUE;
+	panel->backlight.level = PANEL_PWM_MAX_VALUE;
+
+	return 0;
+}
+
+int intel_dsi_dcs_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.backlight.type != INTEL_BACKLIGHT_DSI_DCS)
+		return -ENODEV;
+
+	if (WARN_ON(encoder->type != INTEL_OUTPUT_DSI))
+		return -EINVAL;
+
+	panel->backlight.setup = dcs_setup_backlight;
+	panel->backlight.enable = dcs_enable_backlight;
+	panel->backlight.disable = dcs_disable_backlight;
+	panel->backlight.set = dcs_set_backlight;
+	panel->backlight.get = dcs_get_backlight;
+
+	return 0;
+}

drivers/gpu/drm/i915/intel_panel.c

@@ -1722,6 +1722,10 @@ intel_panel_init_backlight_funcs(struct intel_panel *panel)
 	    intel_dp_aux_init_backlight_funcs(connector) == 0)
 		return;
 
+	if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI &&
+	    intel_dsi_dcs_init_backlight_funcs(connector) == 0)
+		return;
+
 	if (IS_BROXTON(dev_priv)) {
 		panel->backlight.setup = bxt_setup_backlight;
 		panel->backlight.enable = bxt_enable_backlight;