[4/5] drm/i915: Add DCS control for Panel PWM

Submitted by Deepak M on March 28, 2016, 9:39 a.m.

Details

Message ID 1459157997-4447-1-git-send-email-m.deepak@intel.com
State New
Headers show
Series "Series without cover letter" ( rev: 1 ) in Intel GFX

Not browsing as part of any series.

Commit Message

Deepak M March 28, 2016, 9:39 a.m.
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

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>
---

Should this below check be moved to intel_panel.c before calling the
intel_dsi_panel_pwm_init_backlight_funcs() ??
      
	 if (dev_priv->vbt.backlight.pwm_pin ==
                       BLC_CONTROL_PIN_PANEL_PWM)

 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           |  24 ++++-
 drivers/gpu/drm/i915/intel_dsi.h           |   4 +
 drivers/gpu/drm/i915/intel_dsi_panel_pwm.c | 160 +++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_panel.c         |   4 +
 7 files changed, 193 insertions(+), 3 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/intel_dsi_panel_pwm.c

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 7ffb51b..92abbee 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_panel_pwm.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 30321e6..7d6118d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3491,7 +3491,6 @@  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 02a74b0..0603c9f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1330,6 +1330,8 @@  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_panel_pwm.c */
+int intel_dsi_panel_pwm_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..1ba757a 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -1209,10 +1209,30 @@  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
+
+		/*
+		 * Based on the VBT value assign the ports on
+		 * which Panel PWM On/OFF DCS coomands needs to be sent
+		 */
+		switch (dev_priv->vbt.dsi.config->dl_panel_pwm_ports) {
+		case PANEL_PWM_PORT_A:
+			intel_dsi->panel_pwm_dcs_ports = BIT(PORT_A);
+			break;
+		case PANEL_PWM_PORT_C:
+			intel_dsi->panel_pwm_dcs_ports = BIT(PORT_C);
+			break;
+		case PANEL_PWM_PORT_A_AND_C:
+			intel_dsi->panel_pwm_dcs_ports = BIT(PORT_A) | BIT(PORT_C);
+			break;
+		default:
+			intel_dsi->panel_pwm_dcs_ports = BIT(PORT_A) | BIT(PORT_C);
+		}
+	} else {
 		intel_dsi->ports = BIT(port);
+		intel_dsi->panel_pwm_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 f54748d..dcd2265 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 PANEL_PWM_PORT_A		0x00
+#define PANEL_PWM_PORT_C		0x01
+#define PANEL_PWM_PORT_A_AND_C		0x02
+
 struct intel_dsi_host;
 
 struct intel_dsi {
diff --git a/drivers/gpu/drm/i915/intel_dsi_panel_pwm.c b/drivers/gpu/drm/i915/intel_dsi_panel_pwm.c
new file mode 100644
index 0000000..4d7f0eb
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_dsi_panel_pwm.c
@@ -0,0 +1,160 @@ 
+/*
+ * 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 PANEL_PWM_BKL_EN		(1 << 2)
+#define PANEL_PWM_DISP_DIMMING		(1 << 3)
+#define PANEL_PWM_BCTRL			(1 << 5)
+
+#define PANEL_PWM_MAX_VALUE		0xFF
+
+static u32 panel_pwm_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 */
+	/*
+	 * Sending the DCS commands to the ports to which Panel PWM
+	 * On/Off commands were send
+	 */
+	for_each_dsi_port(port, intel_dsi->panel_pwm_dcs_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 panel_pwm_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;
+	enum port port;
+
+	/* FIXME Need to take care of 16 bit brightness level */
+	/*
+	 * Sending the DCS commands to the ports to which Panel PWM
+	 * On/Off commands were send
+	 */
+	for_each_dsi_port(port, intel_dsi->panel_pwm_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 panel_pwm_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;
+
+	panel_pwm_set_backlight(connector, 0);
+
+	for_each_dsi_port(port, intel_dsi->panel_pwm_dcs_ports) {
+		dsi_device = intel_dsi->dsi_hosts[port]->device;
+		data &= ~PANEL_PWM_BKL_EN; /* Turn Off Backlight */
+		data &= ~PANEL_PWM_DISP_DIMMING; /* Display Dimming Off */
+		data &= ~PANEL_PWM_BCTRL; /* Brightness control Block Off */
+		mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+					&data, sizeof(data));
+	}
+}
+
+static void panel_pwm_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;
+
+	for_each_dsi_port(port, intel_dsi->panel_pwm_dcs_ports) {
+		dsi_device = intel_dsi->dsi_hosts[port]->device;
+		data = PANEL_PWM_BKL_EN /* Turn on backlight */
+			| PANEL_PWM_DISP_DIMMING /* Display Dimming On */
+			| PANEL_PWM_BCTRL; /* Brightness control Block On */
+		mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+					&data, sizeof(data));
+	}
+
+	panel_pwm_set_backlight(connector, panel->backlight.level);
+}
+
+static int panel_pwm_setup_backlight(struct intel_connector *connector,
+		enum pipe unused)
+{
+	struct intel_panel *panel = &connector->panel;
+
+	panel->backlight.max = PANEL_PWM_MAX_VALUE;
+	/* Assigning the MAX value during the setup */
+	panel->backlight.level = PANEL_PWM_MAX_VALUE;
+
+	return 0;
+}
+
+int intel_dsi_panel_pwm_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;
+
+	/*
+	 * Continue initalizing only if the PWM source is
+	 * from the panel
+	 */
+	if (dev_priv->vbt.backlight.pwm_pin !=
+			BLC_CONTROL_PIN_PANEL_PWM)
+		return -ENODEV;
+
+	if (WARN_ON(encoder->type != INTEL_OUTPUT_DSI))
+		return -EINVAL;
+
+	panel->backlight.setup = panel_pwm_setup_backlight;
+	panel->backlight.enable = panel_pwm_enable_backlight;
+	panel->backlight.disable = panel_pwm_disable_backlight;
+	panel->backlight.set = panel_pwm_set_backlight;
+	panel->backlight.get = panel_pwm_get_backlight;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 8c8996f..46ca2de 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_panel_pwm_init_backlight_funcs(connector) == 0)
+		return;
+
 	if (IS_BROXTON(dev_priv)) {
 		panel->backlight.setup = bxt_setup_backlight;
 		panel->backlight.enable = bxt_enable_backlight;

Comments

On Mon, 28 Mar 2016, Deepak M <m.deepak@intel.com> wrote:
> 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

I did not ask for the rename. Maybe the original one wasn't good, but
your suggested name is worse than the original. Now it conflates matters
with the PWM infrastucture controlled backlight in intel_panel.c, while
this file is about DSI DCS controlled backlight. However intel_dsi_dcs.c
would *not* be good, because this is about backlight control.

Please rename to intel_dsi_dcs_backlight.c instead.

I only got patches 2/5 and 4/5. Please resend the full series as one
thread. I won't review this further before that.

BR,
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>
> ---
>
> Should this below check be moved to intel_panel.c before calling the
> intel_dsi_panel_pwm_init_backlight_funcs() ??
>       
> 	 if (dev_priv->vbt.backlight.pwm_pin ==
>                        BLC_CONTROL_PIN_PANEL_PWM)
>
>  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           |  24 ++++-
>  drivers/gpu/drm/i915/intel_dsi.h           |   4 +
>  drivers/gpu/drm/i915/intel_dsi_panel_pwm.c | 160 +++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_panel.c         |   4 +
>  7 files changed, 193 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/gpu/drm/i915/intel_dsi_panel_pwm.c
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 7ffb51b..92abbee 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_panel_pwm.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 30321e6..7d6118d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -3491,7 +3491,6 @@ 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 02a74b0..0603c9f 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1330,6 +1330,8 @@ 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_panel_pwm.c */
> +int intel_dsi_panel_pwm_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..1ba757a 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -1209,10 +1209,30 @@ 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
> +
> +		/*
> +		 * Based on the VBT value assign the ports on
> +		 * which Panel PWM On/OFF DCS coomands needs to be sent
> +		 */
> +		switch (dev_priv->vbt.dsi.config->dl_panel_pwm_ports) {
> +		case PANEL_PWM_PORT_A:
> +			intel_dsi->panel_pwm_dcs_ports = BIT(PORT_A);
> +			break;
> +		case PANEL_PWM_PORT_C:
> +			intel_dsi->panel_pwm_dcs_ports = BIT(PORT_C);
> +			break;
> +		case PANEL_PWM_PORT_A_AND_C:
> +			intel_dsi->panel_pwm_dcs_ports = BIT(PORT_A) | BIT(PORT_C);
> +			break;
> +		default:
> +			intel_dsi->panel_pwm_dcs_ports = BIT(PORT_A) | BIT(PORT_C);
> +		}
> +	} else {
>  		intel_dsi->ports = BIT(port);
> +		intel_dsi->panel_pwm_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 f54748d..dcd2265 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 PANEL_PWM_PORT_A		0x00
> +#define PANEL_PWM_PORT_C		0x01
> +#define PANEL_PWM_PORT_A_AND_C		0x02
> +
>  struct intel_dsi_host;
>  
>  struct intel_dsi {
> diff --git a/drivers/gpu/drm/i915/intel_dsi_panel_pwm.c b/drivers/gpu/drm/i915/intel_dsi_panel_pwm.c
> new file mode 100644
> index 0000000..4d7f0eb
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/intel_dsi_panel_pwm.c
> @@ -0,0 +1,160 @@
> +/*
> + * 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 PANEL_PWM_BKL_EN		(1 << 2)
> +#define PANEL_PWM_DISP_DIMMING		(1 << 3)
> +#define PANEL_PWM_BCTRL			(1 << 5)
> +
> +#define PANEL_PWM_MAX_VALUE		0xFF
> +
> +static u32 panel_pwm_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 */
> +	/*
> +	 * Sending the DCS commands to the ports to which Panel PWM
> +	 * On/Off commands were send
> +	 */
> +	for_each_dsi_port(port, intel_dsi->panel_pwm_dcs_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 panel_pwm_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;
> +	enum port port;
> +
> +	/* FIXME Need to take care of 16 bit brightness level */
> +	/*
> +	 * Sending the DCS commands to the ports to which Panel PWM
> +	 * On/Off commands were send
> +	 */
> +	for_each_dsi_port(port, intel_dsi->panel_pwm_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 panel_pwm_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;
> +
> +	panel_pwm_set_backlight(connector, 0);
> +
> +	for_each_dsi_port(port, intel_dsi->panel_pwm_dcs_ports) {
> +		dsi_device = intel_dsi->dsi_hosts[port]->device;
> +		data &= ~PANEL_PWM_BKL_EN; /* Turn Off Backlight */
> +		data &= ~PANEL_PWM_DISP_DIMMING; /* Display Dimming Off */
> +		data &= ~PANEL_PWM_BCTRL; /* Brightness control Block Off */
> +		mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_CONTROL_DISPLAY,
> +					&data, sizeof(data));
> +	}
> +}
> +
> +static void panel_pwm_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;
> +
> +	for_each_dsi_port(port, intel_dsi->panel_pwm_dcs_ports) {
> +		dsi_device = intel_dsi->dsi_hosts[port]->device;
> +		data = PANEL_PWM_BKL_EN /* Turn on backlight */
> +			| PANEL_PWM_DISP_DIMMING /* Display Dimming On */
> +			| PANEL_PWM_BCTRL; /* Brightness control Block On */
> +		mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_CONTROL_DISPLAY,
> +					&data, sizeof(data));
> +	}
> +
> +	panel_pwm_set_backlight(connector, panel->backlight.level);
> +}
> +
> +static int panel_pwm_setup_backlight(struct intel_connector *connector,
> +		enum pipe unused)
> +{
> +	struct intel_panel *panel = &connector->panel;
> +
> +	panel->backlight.max = PANEL_PWM_MAX_VALUE;
> +	/* Assigning the MAX value during the setup */
> +	panel->backlight.level = PANEL_PWM_MAX_VALUE;
> +
> +	return 0;
> +}
> +
> +int intel_dsi_panel_pwm_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;
> +
> +	/*
> +	 * Continue initalizing only if the PWM source is
> +	 * from the panel
> +	 */
> +	if (dev_priv->vbt.backlight.pwm_pin !=
> +			BLC_CONTROL_PIN_PANEL_PWM)
> +		return -ENODEV;
> +
> +	if (WARN_ON(encoder->type != INTEL_OUTPUT_DSI))
> +		return -EINVAL;
> +
> +	panel->backlight.setup = panel_pwm_setup_backlight;
> +	panel->backlight.enable = panel_pwm_enable_backlight;
> +	panel->backlight.disable = panel_pwm_disable_backlight;
> +	panel->backlight.set = panel_pwm_set_backlight;
> +	panel->backlight.get = panel_pwm_get_backlight;
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> index 8c8996f..46ca2de 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_panel_pwm_init_backlight_funcs(connector) == 0)
> +		return;
> +
>  	if (IS_BROXTON(dev_priv)) {
>  		panel->backlight.setup = bxt_setup_backlight;
>  		panel->backlight.enable = bxt_enable_backlight;