3 files changed, 40 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
index af0b47652752..f7ad6a585129 100644
--- a/drivers/gpu/drm/i915/intel_bios.h
+++ b/drivers/gpu/drm/i915/intel_bios.h
@@ -778,6 +778,13 @@ int intel_parse_bios(struct drm_device *dev);
 #define MIPI_DSI_UNDEFINED_PANEL_ID     0
 #define MIPI_DSI_GENERIC_PANEL_ID       1
 
+/*
+ * PMIC vs SoC Backlight support specified in pwm_blc
+ * field in mipi_config block below.
+*/
+#define PPS_BLC_PMIC   0
+#define PPS_BLC_SOC    1
+
 struct mipi_config {
         u16 panel_id;
 
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index b5a5558ecd63..c4db74a5e4e7 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -31,6 +31,7 @@
 #include <drm/drm_panel.h>
 #include <drm/drm_mipi_dsi.h>
 #include <linux/slab.h>
+#include <linux/gpio/consumer.h>
 #include "i915_drv.h"
 #include "intel_drv.h"
 #include "intel_dsi.h"
@@ -415,6 +416,12 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder)
 
         DRM_DEBUG_KMS("\n");
 
+        /* Panel Enable over CRC PMIC */
+        if (intel_dsi->gpio_panel)
+                gpiod_set_value_cansleep(intel_dsi->gpio_panel, 1);
+
+        msleep(intel_dsi->panel_on_delay);
+
         /* Disable DPOunit clock gating, can stall pipe
          * and we need DPLL REFA always enabled */
         tmp = I915_READ(DPLL(pipe));
@@ -432,8 +439,6 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder)
         /* put device in ready state */
         intel_dsi_device_ready(encoder);
 
-        msleep(intel_dsi->panel_on_delay);
-
         drm_panel_prepare(intel_dsi->panel);
 
         for_each_dsi_port(port, intel_dsi->ports)
@@ -576,6 +581,10 @@ static void intel_dsi_post_disable(struct intel_encoder *encoder)
 
         msleep(intel_dsi->panel_off_delay);
         msleep(intel_dsi->panel_pwr_cycle_delay);
+
+        /* Panel Disable over CRC PMIC */
+        if (intel_dsi->gpio_panel)
+                gpiod_set_value_cansleep(intel_dsi->gpio_panel, 0);
 }
 
 static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,
@@ -955,6 +964,11 @@ static void intel_dsi_encoder_destroy(struct drm_encoder *encoder)
                 /* XXX: Logically this call belongs in the panel driver. */
                 drm_panel_remove(intel_dsi->panel);
         }
+
+        /* dispose of the gpios */
+        if (intel_dsi->gpio_panel)
+                gpiod_put(intel_dsi->gpio_panel);
+
         intel_encoder_destroy(encoder);
 }
 
@@ -1071,6 +1085,20 @@ void intel_dsi_init(struct drm_device *dev)
                 goto err;
         }
 
+        /*
+         * In case of BYT with CRC PMIC, we need to use GPIO for
+         * Panel control.
+         */
+        if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) {
+                intel_dsi->gpio_panel =
+                        gpiod_get(dev->dev, "panel", GPIOD_OUT_HIGH);
+
+                if (IS_ERR(intel_dsi->gpio_panel)) {
+                        DRM_ERROR("Failed to own gpio for panel control\n");
+                        intel_dsi->gpio_panel = NULL;
+                }
+        }
+
         intel_encoder->type = INTEL_OUTPUT_DSI;
         intel_encoder->cloneable = 0;
         drm_connector_init(dev, connector, &intel_dsi_connector_funcs,
diff --git a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h
index 2784ac442368..42a68593e32a 100644
--- a/drivers/gpu/drm/i915/intel_dsi.h
+++ b/drivers/gpu/drm/i915/intel_dsi.h
@@ -42,6 +42,9 @@ struct intel_dsi {
         struct drm_panel *panel;
         struct intel_dsi_host *dsi_hosts[I915_MAX_PORTS];
 
+        /* GPIO Desc for CRC based Panel control */
+        struct gpio_desc *gpio_panel;
+
         struct intel_connector *attached_connector;
 
         /* bit mask of ports being driven */