[PATCH v2 0/2] drm: Add drm_bridge and PTN3460 bridge driver

[PATCH v2 0/2] drm: Add drm_bridge and PTN3460 bridge driver

[Sean Paul]

This patchset adds the drm_bridge abstraction as well as the PTN3460
DisplayPort to LVDS bridge driver (using drm_bridge, of course).

Changed in v2:
 - Added PTN3460 driver to show drm_bridge usage
 - Removed connector detect() re-route in favor of implementing the connector
   in the bridge driver
 - Removed the drm_bridge_helper_funcs and stuck everything in drm_bridge_funcs
 - Added driver_private to drm_bridge

Sean Paul (2):
  drm: Add drm_bridge
  drm/bridge: Add PTN3460 bridge driver

 .../devicetree/bindings/drm/bridge/ptn3460.txt     |  27 ++
 drivers/gpu/drm/Kconfig                            |   2 +
 drivers/gpu/drm/Makefile                           |   1 +
 drivers/gpu/drm/bridge/Kconfig                     |   5 +
 drivers/gpu/drm/bridge/Makefile                    |   3 +
 drivers/gpu/drm/bridge/ptn3460.c                   | 349 +++++++++++++++++++++
 drivers/gpu/drm/drm_crtc.c                         |  50 +++
 drivers/gpu/drm/drm_crtc_helper.c                  |  89 ++++--
 include/drm/bridge/ptn3460.h                       |  36 +++
 include/drm/drm_crtc.h                             |  55 ++++
 10 files changed, 598 insertions(+), 19 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/drm/bridge/ptn3460.txt
 create mode 100644 drivers/gpu/drm/bridge/Kconfig
 create mode 100644 drivers/gpu/drm/bridge/Makefile
 create mode 100644 drivers/gpu/drm/bridge/ptn3460.c
 create mode 100644 include/drm/bridge/ptn3460.h

-- 
1.8.3

[PATCH v2 1/2] drm: Add drm_bridge

[Sean Paul]

This patch adds the notion of a drm_bridge. A bridge is a chained
device which hangs off an encoder. The drm driver using the bridge
should provide the association between encoder and bridge. Once a
bridge is associated with an encoder, it will participate in mode
set, and dpms (via the enable/disable hooks).

Signed-off-by: Sean Paul <seanpaul@chromium.org>
---
 drivers/gpu/drm/drm_crtc.c        | 50 ++++++++++++++++++++++
 drivers/gpu/drm/drm_crtc_helper.c | 89 ++++++++++++++++++++++++++++++---------
 include/drm/drm_crtc.h            | 55 ++++++++++++++++++++++++
 3 files changed, 175 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index fc83bb9..0311e2b 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -781,6 +781,41 @@ void drm_connector_unplug_all(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_connector_unplug_all);
 
+int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
+		const struct drm_bridge_funcs *funcs)
+{
+	int ret;
+
+	drm_modeset_lock_all(dev);
+
+	ret = drm_mode_object_get(dev, &bridge->base, DRM_MODE_OBJECT_BRIDGE);
+	if (ret)
+		goto out;
+
+	bridge->dev = dev;
+	bridge->funcs = funcs;
+
+	list_add_tail(&bridge->head, &dev->mode_config.bridge_list);
+	dev->mode_config.num_bridge++;
+
+ out:
+	drm_modeset_unlock_all(dev);
+	return ret;
+}
+EXPORT_SYMBOL(drm_bridge_init);
+
+void drm_bridge_cleanup(struct drm_bridge *bridge)
+{
+	struct drm_device *dev = bridge->dev;
+
+	drm_modeset_lock_all(dev);
+	drm_mode_object_put(dev, &bridge->base);
+	list_del(&bridge->head);
+	dev->mode_config.num_bridge--;
+	drm_modeset_unlock_all(dev);
+}
+EXPORT_SYMBOL(drm_bridge_cleanup);
+
 int drm_encoder_init(struct drm_device *dev,
 		      struct drm_encoder *encoder,
 		      const struct drm_encoder_funcs *funcs,
@@ -1190,6 +1225,7 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
 	total_objects += dev->mode_config.num_crtc;
 	total_objects += dev->mode_config.num_connector;
 	total_objects += dev->mode_config.num_encoder;
+	total_objects += dev->mode_config.num_bridge;
 
 	group->id_list = kzalloc(total_objects * sizeof(uint32_t), GFP_KERNEL);
 	if (!group->id_list)
@@ -1198,6 +1234,7 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
 	group->num_crtcs = 0;
 	group->num_connectors = 0;
 	group->num_encoders = 0;
+	group->num_bridges = 0;
 	return 0;
 }
 
@@ -1207,6 +1244,7 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
 	struct drm_crtc *crtc;
 	struct drm_encoder *encoder;
 	struct drm_connector *connector;
+	struct drm_bridge *bridge;
 	int ret;
 
 	if ((ret = drm_mode_group_init(dev, group)))
@@ -1223,6 +1261,11 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
 		group->id_list[group->num_crtcs + group->num_encoders +
 			       group->num_connectors++] = connector->base.id;
 
+	list_for_each_entry(bridge, &dev->mode_config.bridge_list, head)
+		group->id_list[group->num_crtcs + group->num_encoders +
+			       group->num_connectors + group->num_bridges++] =
+					bridge->base.id;
+
 	return 0;
 }
 EXPORT_SYMBOL(drm_mode_group_init_legacy_group);
@@ -3905,6 +3948,7 @@ void drm_mode_config_init(struct drm_device *dev)
 	INIT_LIST_HEAD(&dev->mode_config.fb_list);
 	INIT_LIST_HEAD(&dev->mode_config.crtc_list);
 	INIT_LIST_HEAD(&dev->mode_config.connector_list);
+	INIT_LIST_HEAD(&dev->mode_config.bridge_list);
 	INIT_LIST_HEAD(&dev->mode_config.encoder_list);
 	INIT_LIST_HEAD(&dev->mode_config.property_list);
 	INIT_LIST_HEAD(&dev->mode_config.property_blob_list);
@@ -3941,6 +3985,7 @@ void drm_mode_config_cleanup(struct drm_device *dev)
 	struct drm_connector *connector, *ot;
 	struct drm_crtc *crtc, *ct;
 	struct drm_encoder *encoder, *enct;
+	struct drm_bridge *bridge, *brt;
 	struct drm_framebuffer *fb, *fbt;
 	struct drm_property *property, *pt;
 	struct drm_property_blob *blob, *bt;
@@ -3951,6 +3996,11 @@ void drm_mode_config_cleanup(struct drm_device *dev)
 		encoder->funcs->destroy(encoder);
 	}
 
+	list_for_each_entry_safe(bridge, brt,
+				 &dev->mode_config.bridge_list, head) {
+		bridge->funcs->destroy(bridge);
+	}
+
 	list_for_each_entry_safe(connector, ot,
 				 &dev->mode_config.connector_list, head) {
 		connector->funcs->destroy(connector);
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 6a64749..c722c3b 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -257,10 +257,16 @@ drm_encoder_disable(struct drm_encoder *encoder)
 {
 	struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 
+	if (encoder->bridge)
+		encoder->bridge->funcs->disable(encoder->bridge);
+
 	if (encoder_funcs->disable)
 		(*encoder_funcs->disable)(encoder);
 	else
 		(*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
+
+	if (encoder->bridge)
+		encoder->bridge->funcs->post_disable(encoder->bridge);
 }
 
 /**
@@ -424,6 +430,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 
 		if (encoder->crtc != crtc)
 			continue;
+
+		if (encoder->bridge && encoder->bridge->funcs->mode_fixup) {
+			ret = encoder->bridge->funcs->mode_fixup(
+					encoder->bridge, mode, adjusted_mode);
+			if (!ret) {
+				DRM_DEBUG_KMS("Bridge fixup failed\n");
+				goto done;
+			}
+		}
+
 		encoder_funcs = encoder->helper_private;
 		if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 						      adjusted_mode))) {
@@ -443,9 +459,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 
 		if (encoder->crtc != crtc)
 			continue;
+
+		if (encoder->bridge)
+			encoder->bridge->funcs->disable(encoder->bridge);
+
 		encoder_funcs = encoder->helper_private;
 		/* Disable the encoders as the first thing we do. */
 		encoder_funcs->prepare(encoder);
+
+		if (encoder->bridge)
+			encoder->bridge->funcs->post_disable(encoder->bridge);
 	}
 
 	drm_crtc_prepare_encoders(dev);
@@ -469,6 +492,10 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 			mode->base.id, mode->name);
 		encoder_funcs = encoder->helper_private;
 		encoder_funcs->mode_set(encoder, mode, adjusted_mode);
+
+		if (encoder->bridge && encoder->bridge->funcs->mode_set)
+			encoder->bridge->funcs->mode_set(encoder->bridge, mode,
+					adjusted_mode);
 	}
 
 	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
@@ -479,9 +506,14 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 		if (encoder->crtc != crtc)
 			continue;
 
+		if (encoder->bridge)
+			encoder->bridge->funcs->pre_enable(encoder->bridge);
+
 		encoder_funcs = encoder->helper_private;
 		encoder_funcs->commit(encoder);
 
+		if (encoder->bridge)
+			encoder->bridge->funcs->enable(encoder->bridge);
 	}
 
 	/* Store real post-adjustment hardware mode. */
@@ -830,6 +862,31 @@ static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 	return dpms;
 }
 
+/* Helper which handles bridge ordering around encoder dpms */
+static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+	struct drm_bridge *bridge = encoder->bridge;
+	struct drm_encoder_helper_funcs *encoder_funcs;
+
+	if (bridge) {
+		if (mode == DRM_MODE_DPMS_ON)
+			bridge->funcs->pre_enable(bridge);
+		else
+			bridge->funcs->disable(bridge);
+	}
+
+	encoder_funcs = encoder->helper_private;
+	if (encoder_funcs->dpms)
+		encoder_funcs->dpms(encoder, mode);
+
+	if (bridge) {
+		if (mode == DRM_MODE_DPMS_ON)
+			bridge->funcs->enable(bridge);
+		else
+			bridge->funcs->post_disable(bridge);
+	}
+}
+
 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 {
 	int dpms = DRM_MODE_DPMS_OFF;
@@ -857,7 +914,7 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 {
 	struct drm_encoder *encoder = connector->encoder;
 	struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
-	int old_dpms;
+	int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 
 	if (mode == connector->dpms)
 		return;
@@ -865,6 +922,9 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 	old_dpms = connector->dpms;
 	connector->dpms = mode;
 
+	if (encoder)
+		encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
+
 	/* from off to on, do crtc then encoder */
 	if (mode < old_dpms) {
 		if (crtc) {
@@ -873,22 +933,14 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 				(*crtc_funcs->dpms) (crtc,
 						     drm_helper_choose_crtc_dpms(crtc));
 		}
-		if (encoder) {
-			struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
-			if (encoder_funcs->dpms)
-				(*encoder_funcs->dpms) (encoder,
-							drm_helper_choose_encoder_dpms(encoder));
-		}
+		if (encoder)
+			drm_helper_encoder_dpms(encoder, encoder_dpms);
 	}
 
 	/* from on to off, do encoder then crtc */
 	if (mode > old_dpms) {
-		if (encoder) {
-			struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
-			if (encoder_funcs->dpms)
-				(*encoder_funcs->dpms) (encoder,
-							drm_helper_choose_encoder_dpms(encoder));
-		}
+		if (encoder)
+			drm_helper_encoder_dpms(encoder, encoder_dpms);
 		if (crtc) {
 			struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 			if (crtc_funcs->dpms)
@@ -924,9 +976,8 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
 {
 	struct drm_crtc *crtc;
 	struct drm_encoder *encoder;
-	struct drm_encoder_helper_funcs *encoder_funcs;
 	struct drm_crtc_helper_funcs *crtc_funcs;
-	int ret;
+	int ret, encoder_dpms;
 
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 
@@ -946,10 +997,10 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
 				if(encoder->crtc != crtc)
 					continue;
 
-				encoder_funcs = encoder->helper_private;
-				if (encoder_funcs->dpms)
-					(*encoder_funcs->dpms) (encoder,
-								drm_helper_choose_encoder_dpms(encoder));
+				encoder_dpms = drm_helper_choose_encoder_dpms(
+							encoder);
+
+				drm_helper_encoder_dpms(encoder, encoder_dpms);
 			}
 
 			crtc_funcs = crtc->helper_private;
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index fa12a2f..a26d3d9 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -49,6 +49,7 @@ struct drm_clip_rect;
 #define DRM_MODE_OBJECT_FB 0xfbfbfbfb
 #define DRM_MODE_OBJECT_BLOB 0xbbbbbbbb
 #define DRM_MODE_OBJECT_PLANE 0xeeeeeeee
+#define DRM_MODE_OBJECT_BRIDGE 0xbdbdbdbd
 
 struct drm_mode_object {
 	uint32_t id;
@@ -305,6 +306,7 @@ struct drm_connector;
 struct drm_encoder;
 struct drm_pending_vblank_event;
 struct drm_plane;
+struct drm_bridge;
 
 /**
  * drm_crtc_funcs - control CRTCs for a given device
@@ -507,6 +509,7 @@ struct drm_encoder_funcs {
  * @possible_crtcs: bitmask of potential CRTC bindings
  * @possible_clones: bitmask of potential sibling encoders for cloning
  * @crtc: currently bound CRTC
+ * @bridge: bridge associated to the encoder
  * @funcs: control functions
  * @helper_private: mid-layer private data
  *
@@ -523,6 +526,7 @@ struct drm_encoder {
 	uint32_t possible_clones;
 
 	struct drm_crtc *crtc;
+	struct drm_bridge *bridge;
 	const struct drm_encoder_funcs *funcs;
 	void *helper_private;
 };
@@ -683,6 +687,48 @@ struct drm_plane {
 };
 
 /**
+ * drm_bridge_funcs - drm_bridge control functions
+ * @mode_fixup: Try to fixup (or reject entirely) proposed mode for this bridge
+ * @disable: Called right before encoder prepare, disables the bridge
+ * @post_disable: Called right after encoder prepare, for lockstepped disable
+ * @mode_set: Set this mode to the bridge
+ * @pre_enable: Called right before encoder commit, for lockstepped commit
+ * @enable: Called right after encoder commit, enables the bridge
+ * @destroy: make object go away
+ */
+struct drm_bridge_funcs {
+	bool (*mode_fixup)(struct drm_bridge *bridge,
+			   const struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode);
+	void (*disable)(struct drm_bridge *bridge);
+	void (*post_disable)(struct drm_bridge *bridge);
+	void (*mode_set)(struct drm_bridge *bridge,
+			 struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode);
+	void (*pre_enable)(struct drm_bridge *bridge);
+	void (*enable)(struct drm_bridge *bridge);
+	void (*destroy)(struct drm_bridge *bridge);
+};
+
+/**
+ * drm_bridge - central DRM bridge control structure
+ * @dev: DRM device this bridge belongs to
+ * @head: list management
+ * @base: base mode object
+ * @funcs: control functions
+ * @driver_private: pointer to the bridge driver's internal context
+ */
+struct drm_bridge {
+	struct drm_device *dev;
+	struct list_head head;
+
+	struct drm_mode_object base;
+
+	const struct drm_bridge_funcs *funcs;
+	void *driver_private;
+};
+
+/**
  * drm_mode_set - new values for a CRTC config change
  * @head: list management
  * @fb: framebuffer to use for new config
@@ -742,6 +788,7 @@ struct drm_mode_group {
 	uint32_t num_crtcs;
 	uint32_t num_encoders;
 	uint32_t num_connectors;
+	uint32_t num_bridges;
 
 	/* list of object IDs for this group */
 	uint32_t *id_list;
@@ -756,6 +803,8 @@ struct drm_mode_group {
  * @fb_list: list of framebuffers available
  * @num_connector: number of connectors on this device
  * @connector_list: list of connector objects
+ * @num_bridge: number of bridges on this device
+ * @bridge_list: list of bridge objects
  * @num_encoder: number of encoders on this device
  * @encoder_list: list of encoder objects
  * @num_crtc: number of CRTCs on this device
@@ -793,6 +842,8 @@ struct drm_mode_config {
 
 	int num_connector;
 	struct list_head connector_list;
+	int num_bridge;
+	struct list_head bridge_list;
 	int num_encoder;
 	struct list_head encoder_list;
 	int num_plane;
@@ -878,6 +929,10 @@ extern void drm_connector_cleanup(struct drm_connector *connector);
 /* helper to unplug all connectors from sysfs for device */
 extern void drm_connector_unplug_all(struct drm_device *dev);
 
+extern int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
+			   const struct drm_bridge_funcs *funcs);
+extern void drm_bridge_cleanup(struct drm_bridge *bridge);
+
 extern int drm_encoder_init(struct drm_device *dev,
 			    struct drm_encoder *encoder,
 			    const struct drm_encoder_funcs *funcs,
-- 
1.8.3

[PATCH v2 2/2] drm/bridge: Add PTN3460 bridge driver

[Sean Paul]

This patch adds a drm_bridge driver for the PTN3460 DisplayPort to LVDS
bridge chip.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
---
 .../devicetree/bindings/drm/bridge/ptn3460.txt     |  27 ++
 drivers/gpu/drm/Kconfig                            |   2 +
 drivers/gpu/drm/Makefile                           |   1 +
 drivers/gpu/drm/bridge/Kconfig                     |   5 +
 drivers/gpu/drm/bridge/Makefile                    |   3 +
 drivers/gpu/drm/bridge/ptn3460.c                   | 349 +++++++++++++++++++++
 include/drm/bridge/ptn3460.h                       |  36 +++
 7 files changed, 423 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/drm/bridge/ptn3460.txt
 create mode 100644 drivers/gpu/drm/bridge/Kconfig
 create mode 100644 drivers/gpu/drm/bridge/Makefile
 create mode 100644 drivers/gpu/drm/bridge/ptn3460.c
 create mode 100644 include/drm/bridge/ptn3460.h

diff --git a/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt b/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt
new file mode 100644
index 0000000..c1cd329
--- /dev/null
+++ b/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt
@@ -0,0 +1,27 @@
+ptn3460-bridge bindings
+
+Required properties:
+	- compatible: "nxp,ptn3460"
+	- reg: i2c address of the bridge
+	- powerdown-gpio: OF device-tree gpio specification
+	- reset-gpio: OF device-tree gpio specification
+	- edid-emulation: The EDID emulation entry to use
+		+-------+------------+------------------+
+		| Value | Resolution | Description      |
+		|   0   |  1024x768  | NXP Generic      |
+		|   1   |  1920x1080 | NXP Generic      |
+		|   2   |  1920x1080 | NXP Generic      |
+		|   3   |  1600x900  | Samsung LTM200KT |
+		|   4   |  1920x1080 | Samsung LTM230HT |
+		|   5   |  1366x768  | NXP Generic      |
+		|   6   |  1600x900  | ChiMei M215HGE   |
+		+-------+------------+------------------+
+
+Example:
+	ptn3460-bridge@20 {
+		compatible = "nxp,ptn3460";
+		reg = <0x20>;
+		powerdown-gpio = <&gpy2 5 1 0 0>;
+		reset-gpio = <&gpx1 5 1 0 0>;
+		edid-emulation = <5>;
+	};
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index a7c54c8..6105a34 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -223,3 +223,5 @@ source "drivers/gpu/drm/omapdrm/Kconfig"
 source "drivers/gpu/drm/tilcdc/Kconfig"
 
 source "drivers/gpu/drm/qxl/Kconfig"
+
+source "drivers/gpu/drm/bridge/Kconfig"
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index d943b94..c2ae293 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -55,3 +55,4 @@ obj-$(CONFIG_DRM_OMAP)	+= omapdrm/
 obj-$(CONFIG_DRM_TILCDC)	+= tilcdc/
 obj-$(CONFIG_DRM_QXL) += qxl/
 obj-y			+= i2c/
+obj-y			+= bridge/
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
new file mode 100644
index 0000000..27a83b5
--- /dev/null
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -0,0 +1,5 @@
+config DRM_PTN3460
+	tristate "PTN3460 DP/LVDS bridge"
+	depends on DRM && I2C
+	---help---
+	  Adds the driver for the NXP PTN3460 DP/LVDS bridge chip.
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
new file mode 100644
index 0000000..b4733e1
--- /dev/null
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -0,0 +1,3 @@
+ccflags-y := -Iinclude/drm
+
+obj-$(CONFIG_DRM_PTN3460) += ptn3460.o
diff --git a/drivers/gpu/drm/bridge/ptn3460.c b/drivers/gpu/drm/bridge/ptn3460.c
new file mode 100644
index 0000000..a9e5c1a
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ptn3460.c
@@ -0,0 +1,349 @@
+/*
+ * NXP PTN3460 DP/LVDS bridge driver
+ *
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+
+#include "drmP.h"
+#include "drm_edid.h"
+#include "drm_crtc.h"
+#include "drm_crtc_helper.h"
+
+#include "bridge/ptn3460.h"
+
+#define PTN3460_EDID_ADDR			0x0
+#define PTN3460_EDID_EMULATION_ADDR		0x84
+#define PTN3460_EDID_ENABLE_EMULATION		0
+#define PTN3460_EDID_EMULATION_SELECTION	1
+#define PTN3460_EDID_SRAM_LOAD_ADDR		0x85
+
+struct ptn3460_bridge {
+	struct drm_connector connector;
+	struct i2c_client *client;
+	struct drm_encoder *encoder;
+	struct drm_bridge *bridge;
+	struct edid *edid;
+	int gpio_pd_n;
+	int gpio_rst_n;
+	u32 edid_emulation;
+	bool enabled;
+};
+
+static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
+		u8 *buf, int len)
+{
+	int ret;
+
+	ret = i2c_master_send(ptn_bridge->client, &addr, 1);
+	if (ret <= 0) {
+		DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
+		return ret;
+	}
+
+	ret = i2c_master_recv(ptn_bridge->client, buf, len);
+	if (ret <= 0) {
+		DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
+		char val)
+{
+	int ret;
+	char buf[2];
+
+	buf[0] = addr;
+	buf[1] = val;
+
+	ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
+	if (ret <= 0) {
+		DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
+{
+	int ret;
+	char val;
+
+	/* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
+	ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
+			ptn_bridge->edid_emulation);
+	if (ret) {
+		DRM_ERROR("Failed to transfer edid to sram, ret=%d\n", ret);
+		return ret;
+	}
+
+	/* Enable EDID emulation and select the desired EDID */
+	val = 1 << PTN3460_EDID_ENABLE_EMULATION |
+		ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;
+
+	ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
+	if (ret) {
+		DRM_ERROR("Failed to write edid value, ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void ptn3460_pre_enable(struct drm_bridge *bridge)
+{
+	struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
+	int ret;
+
+	if (ptn_bridge->enabled)
+		return;
+
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+		gpio_set_value(ptn_bridge->gpio_pd_n, 1);
+
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n)) {
+		gpio_set_value(ptn_bridge->gpio_rst_n, 0);
+		udelay(10);
+		gpio_set_value(ptn_bridge->gpio_rst_n, 1);
+	}
+
+	/*
+	 * There's a bug in the PTN chip where it falsely asserts hotplug before
+	 * it is fully functional. We're forced to wait for the maximum start up
+	 * time specified in the chip's datasheet to make sure we're really up.
+	 */
+	msleep(90);
+
+	ret = ptn3460_select_edid(ptn_bridge);
+	if (ret)
+		DRM_ERROR("Select edid failed ret=%d\n", ret);
+
+	ptn_bridge->enabled = true;
+}
+
+static void ptn3460_enable(struct drm_bridge *bridge)
+{
+}
+
+static void ptn3460_disable(struct drm_bridge *bridge)
+{
+	struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
+
+	if (!ptn_bridge->enabled)
+		return;
+
+	ptn_bridge->enabled = false;
+
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+		gpio_set_value(ptn_bridge->gpio_rst_n, 1);
+
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+		gpio_set_value(ptn_bridge->gpio_pd_n, 0);
+}
+
+static void ptn3460_post_disable(struct drm_bridge *bridge)
+{
+}
+
+void ptn3460_bridge_destroy(struct drm_bridge *bridge)
+{
+	struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
+
+	drm_bridge_cleanup(bridge);
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+		gpio_free(ptn_bridge->gpio_pd_n);
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+		gpio_free(ptn_bridge->gpio_rst_n);
+	/* Nothing else to free, we've got devm allocated memory */
+}
+
+struct drm_bridge_funcs ptn3460_bridge_funcs = {
+	.pre_enable = ptn3460_pre_enable,
+	.enable = ptn3460_enable,
+	.disable = ptn3460_disable,
+	.post_disable = ptn3460_post_disable,
+	.destroy = ptn3460_bridge_destroy,
+};
+
+int ptn3460_get_modes(struct drm_connector *connector)
+{
+	struct ptn3460_bridge *ptn_bridge;
+	u8 *edid;
+	int ret, num_modes;
+	bool power_off;
+
+	ptn_bridge = container_of(connector, struct ptn3460_bridge, connector);
+
+	if (ptn_bridge->edid)
+		return drm_add_edid_modes(connector, ptn_bridge->edid);
+
+	power_off = !ptn_bridge->enabled;
+	ptn3460_pre_enable(ptn_bridge->bridge);
+
+	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
+	if (!edid) {
+		DRM_ERROR("Failed to allocate edid\n");
+		return 0;
+	}
+
+	ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
+			EDID_LENGTH);
+	if (ret) {
+		kfree(edid);
+		num_modes = 0;
+		goto out;
+	}
+
+	ptn_bridge->edid = (struct edid *)edid;
+	drm_mode_connector_update_edid_property(connector, ptn_bridge->edid);
+
+	num_modes = drm_add_edid_modes(connector, ptn_bridge->edid);
+
+out:
+	if (power_off)
+		ptn3460_disable(ptn_bridge->bridge);
+
+	return num_modes;
+}
+
+static int ptn3460_mode_valid(struct drm_connector *connector,
+		struct drm_display_mode *mode)
+{
+	return MODE_OK;
+}
+
+struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
+{
+	struct ptn3460_bridge *ptn_bridge;
+
+	ptn_bridge = container_of(connector, struct ptn3460_bridge, connector);
+
+	return ptn_bridge->encoder;
+}
+
+struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
+	.get_modes = ptn3460_get_modes,
+	.mode_valid = ptn3460_mode_valid,
+	.best_encoder = ptn3460_best_encoder,
+};
+
+enum drm_connector_status ptn3460_detect(struct drm_connector *connector,
+		bool force)
+{
+	return connector_status_connected;
+}
+
+void ptn3460_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_cleanup(connector);
+}
+
+struct drm_connector_funcs ptn3460_connector_funcs = {
+	.dpms = drm_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = ptn3460_detect,
+	.destroy = ptn3460_connector_destroy,
+};
+
+int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
+		struct i2c_client *client, struct device_node *node)
+{
+	int ret;
+	struct drm_bridge *bridge;
+	struct ptn3460_bridge *ptn_bridge;
+
+	bridge = devm_kzalloc(dev->dev, sizeof(*bridge), GFP_KERNEL);
+	if (!bridge) {
+		DRM_ERROR("Failed to allocate drm bridge\n");
+		return -ENOMEM;
+	}
+
+	ptn_bridge = devm_kzalloc(dev->dev, sizeof(*ptn_bridge), GFP_KERNEL);
+	if (!ptn_bridge) {
+		DRM_ERROR("Failed to allocate ptn bridge\n");
+		return -ENOMEM;
+	}
+
+	ptn_bridge->client = client;
+	ptn_bridge->encoder = encoder;
+	ptn_bridge->bridge = bridge;
+	ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n)) {
+		ret = gpio_request_one(ptn_bridge->gpio_pd_n,
+				GPIOF_OUT_INIT_HIGH, "PTN3460_PD_N");
+		if (ret) {
+			DRM_ERROR("Request powerdown-gpio failed (%d)\n", ret);
+			return ret;
+		}
+	}
+
+	ptn_bridge->gpio_rst_n = of_get_named_gpio(node, "reset-gpio", 0);
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n)) {
+		/*
+		 * Request the reset pin low to avoid the bridge being
+		 * initialized prematurely
+		 */
+		ret = gpio_request_one(ptn_bridge->gpio_rst_n,
+				GPIOF_OUT_INIT_LOW, "PTN3460_RST_N");
+		if (ret) {
+			DRM_ERROR("Request reset-gpio failed (%d)\n", ret);
+			gpio_free(ptn_bridge->gpio_pd_n);
+			return ret;
+		}
+	}
+
+	ret = of_property_read_u32(node, "edid-emulation",
+			&ptn_bridge->edid_emulation);
+	if (ret) {
+		DRM_ERROR("Can't read edid emulation value\n");
+		goto err;
+	}
+
+	ret = drm_bridge_init(dev, bridge, &ptn3460_bridge_funcs);
+	if (ret) {
+		DRM_ERROR("Failed to initialize bridge with drm\n");
+		goto err;
+	}
+
+	bridge->driver_private = ptn_bridge;
+	encoder->bridge = bridge;
+
+	ret = drm_connector_init(dev, &ptn_bridge->connector,
+			&ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector with drm\n");
+		goto err;
+	}
+	drm_connector_helper_add(&ptn_bridge->connector,
+			&ptn3460_connector_helper_funcs);
+	drm_sysfs_connector_add(&ptn_bridge->connector);
+	drm_mode_connector_attach_encoder(&ptn_bridge->connector, encoder);
+
+	return 0;
+
+err:
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+		gpio_free(ptn_bridge->gpio_pd_n);
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+		gpio_free(ptn_bridge->gpio_rst_n);
+	return ret;
+}
diff --git a/include/drm/bridge/ptn3460.h b/include/drm/bridge/ptn3460.h
new file mode 100644
index 0000000..157ffa1
--- /dev/null
+++ b/include/drm/bridge/ptn3460.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _DRM_BRIDGE_PTN3460_H_
+#define _DRM_BRIDGE_PTN3460_H_
+
+struct drm_device;
+struct drm_encoder;
+struct i2c_client;
+struct device_node;
+
+#ifdef CONFIG_DRM_PTN3460
+
+int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
+		struct i2c_client *client, struct device_node *node);
+#else
+
+int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
+		struct i2c_client *client, struct device_node *node)
+{
+	return 0;
+}
+
+#endif
+
+#endif
-- 
1.8.3

Re: [PATCH v2 2/2] drm/bridge: Add PTN3460 bridge driver

[Thierry Reding]

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On Wed, Aug 14, 2013 at 04:47:38PM -0400, Sean Paul wrote:
[...]
> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
> +		struct i2c_client *client, struct device_node *node)
[...]
> +	ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);

of_get_named_gpio() can return -EPROBE_DEFER and I wonder how you handle
that in the driver that uses ptn3460_init(). Since you pass in an
initialized drm_device, you'd need to undo all of that in case of
-EPROBE_DEFER. Well I guess you'd have to do that in case of any error,
but it makes things difficult to handle for drivers.

For instance on Tegra we pretty much delay DRM initialization until all
required subdevices (there are quite a few) have been probed, so if we
wanted to use this function we'd have to call it after all drivers have
been probed because only then do we have access to a struct drm_device.
That will cause other problems, however, because at that point we can't
defer probing anymore.

Thierry

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Re: [PATCH v2 2/2] drm/bridge: Add PTN3460 bridge driver

[Sean Paul]

On Thu, Aug 15, 2013 at 11:28 AM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Wed, Aug 14, 2013 at 04:47:38PM -0400, Sean Paul wrote:
> [...]
>> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
>> +             struct i2c_client *client, struct device_node *node)
> [...]
>> +     ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
>
> of_get_named_gpio() can return -EPROBE_DEFER and I wonder how you handle
> that in the driver that uses ptn3460_init(). Since you pass in an
> initialized drm_device, you'd need to undo all of that in case of
> -EPROBE_DEFER. Well I guess you'd have to do that in case of any error,
> but it makes things difficult to handle for drivers.
>
> For instance on Tegra we pretty much delay DRM initialization until all
> required subdevices (there are quite a few) have been probed, so if we
> wanted to use this function we'd have to call it after all drivers have
> been probed because only then do we have access to a struct drm_device.
> That will cause other problems, however, because at that point we can't
> defer probing anymore.
>

I suppose I could add another init that performs the deferrable tasks
(ptn3460_init_deferrable or something). This would be called before
drm init has been started from one of the probe functions.
Alternatively, I could set this up as a standalone i2c driver and do
this stuff in the probe. Any other options?

Adding another init call adds yet another thing the drm driver has to
do to use this bridge. Making the ptn driver standalone requires you
to set things up such that drm init is dependent on ptn probe running
successfully. I'm not sure which is more desirable.

Practically speaking, do you expect to call drm_init before the gpio
is available?

Sean



> Thierry

Re: [PATCH v2 2/2] drm/bridge: Add PTN3460 bridge driver

[Thierry Reding]

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On Thu, Aug 15, 2013 at 03:32:58PM -0400, Sean Paul wrote:
> On Thu, Aug 15, 2013 at 11:28 AM, Thierry Reding
> <thierry.reding@gmail.com> wrote:
> > On Wed, Aug 14, 2013 at 04:47:38PM -0400, Sean Paul wrote:
> > [...]
> >> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
> >> +             struct i2c_client *client, struct device_node *node)
> > [...]
> >> +     ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
> >
> > of_get_named_gpio() can return -EPROBE_DEFER and I wonder how you handle
> > that in the driver that uses ptn3460_init(). Since you pass in an
> > initialized drm_device, you'd need to undo all of that in case of
> > -EPROBE_DEFER. Well I guess you'd have to do that in case of any error,
> > but it makes things difficult to handle for drivers.
> >
> > For instance on Tegra we pretty much delay DRM initialization until all
> > required subdevices (there are quite a few) have been probed, so if we
> > wanted to use this function we'd have to call it after all drivers have
> > been probed because only then do we have access to a struct drm_device.
> > That will cause other problems, however, because at that point we can't
> > defer probing anymore.
> >
> 
> I suppose I could add another init that performs the deferrable tasks
> (ptn3460_init_deferrable or something). This would be called before
> drm init has been started from one of the probe functions.
> Alternatively, I could set this up as a standalone i2c driver and do
> this stuff in the probe. Any other options?

My point was that in those cases you don't have access to the DRM device
yet since you haven't called drm_init() yet.

> Adding another init call adds yet another thing the drm driver has to
> do to use this bridge. Making the ptn driver standalone requires you
> to set things up such that drm init is dependent on ptn probe running
> successfully. I'm not sure which is more desirable.
> 
> Practically speaking, do you expect to call drm_init before the gpio
> is available?

No, not really, but I won't know that the GPIO is available until I
actually call of_get_named_gpio_flags().

But perhaps we should cross that bridge when we get to it.

Thierry

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Re: [PATCH v2 2/2] drm/bridge: Add PTN3460 bridge driver

[Sean Paul]

On Thu, Aug 15, 2013 at 4:42 PM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Thu, Aug 15, 2013 at 03:32:58PM -0400, Sean Paul wrote:
>> On Thu, Aug 15, 2013 at 11:28 AM, Thierry Reding
>> <thierry.reding@gmail.com> wrote:
>> > On Wed, Aug 14, 2013 at 04:47:38PM -0400, Sean Paul wrote:
>> > [...]
>> >> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
>> >> +             struct i2c_client *client, struct device_node *node)
>> > [...]
>> >> +     ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
>> >
>> > of_get_named_gpio() can return -EPROBE_DEFER and I wonder how you handle
>> > that in the driver that uses ptn3460_init(). Since you pass in an
>> > initialized drm_device, you'd need to undo all of that in case of
>> > -EPROBE_DEFER. Well I guess you'd have to do that in case of any error,
>> > but it makes things difficult to handle for drivers.
>> >
>> > For instance on Tegra we pretty much delay DRM initialization until all
>> > required subdevices (there are quite a few) have been probed, so if we
>> > wanted to use this function we'd have to call it after all drivers have
>> > been probed because only then do we have access to a struct drm_device.
>> > That will cause other problems, however, because at that point we can't
>> > defer probing anymore.
>> >
>>
>> I suppose I could add another init that performs the deferrable tasks
>> (ptn3460_init_deferrable or something). This would be called before
>> drm init has been started from one of the probe functions.
>> Alternatively, I could set this up as a standalone i2c driver and do
>> this stuff in the probe. Any other options?
>
> My point was that in those cases you don't have access to the DRM device
> yet since you haven't called drm_init() yet.
>

Yep, I got that. I meant to say we could parse the dt and save the
gpio number for later use when ptn3460_init is called with a
drm_device (thus separating the deferable parts into a place that's
easier to defer). I'm not sure this is worth fixing, TBH.


>> Adding another init call adds yet another thing the drm driver has to
>> do to use this bridge. Making the ptn driver standalone requires you
>> to set things up such that drm init is dependent on ptn probe running
>> successfully. I'm not sure which is more desirable.
>>
>> Practically speaking, do you expect to call drm_init before the gpio
>> is available?
>
> No, not really, but I won't know that the GPIO is available until I
> actually call of_get_named_gpio_flags().
>
> But perhaps we should cross that bridge when we get to it.
>

Pun intended? ;-)

Sean


> Thierry

Re: [PATCH v2 1/2] drm: Add drm_bridge

[Sean Paul]

On Wed, Aug 14, 2013 at 4:47 PM, Sean Paul <seanpaul@chromium.org> wrote:
> This patch adds the notion of a drm_bridge. A bridge is a chained
> device which hangs off an encoder. The drm driver using the bridge
> should provide the association between encoder and bridge. Once a
> bridge is associated with an encoder, it will participate in mode
> set, and dpms (via the enable/disable hooks).
>

Friendly ping. Any feedback?

Sean


> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> ---
>  drivers/gpu/drm/drm_crtc.c        | 50 ++++++++++++++++++++++
>  drivers/gpu/drm/drm_crtc_helper.c | 89 ++++++++++++++++++++++++++++++---------
>  include/drm/drm_crtc.h            | 55 ++++++++++++++++++++++++
>  3 files changed, 175 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index fc83bb9..0311e2b 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -781,6 +781,41 @@ void drm_connector_unplug_all(struct drm_device *dev)
>  }
>  EXPORT_SYMBOL(drm_connector_unplug_all);
>
> +int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
> +               const struct drm_bridge_funcs *funcs)
> +{
> +       int ret;
> +
> +       drm_modeset_lock_all(dev);
> +
> +       ret = drm_mode_object_get(dev, &bridge->base, DRM_MODE_OBJECT_BRIDGE);
> +       if (ret)
> +               goto out;
> +
> +       bridge->dev = dev;
> +       bridge->funcs = funcs;
> +
> +       list_add_tail(&bridge->head, &dev->mode_config.bridge_list);
> +       dev->mode_config.num_bridge++;
> +
> + out:
> +       drm_modeset_unlock_all(dev);
> +       return ret;
> +}
> +EXPORT_SYMBOL(drm_bridge_init);
> +
> +void drm_bridge_cleanup(struct drm_bridge *bridge)
> +{
> +       struct drm_device *dev = bridge->dev;
> +
> +       drm_modeset_lock_all(dev);
> +       drm_mode_object_put(dev, &bridge->base);
> +       list_del(&bridge->head);
> +       dev->mode_config.num_bridge--;
> +       drm_modeset_unlock_all(dev);
> +}
> +EXPORT_SYMBOL(drm_bridge_cleanup);
> +
>  int drm_encoder_init(struct drm_device *dev,
>                       struct drm_encoder *encoder,
>                       const struct drm_encoder_funcs *funcs,
> @@ -1190,6 +1225,7 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
>         total_objects += dev->mode_config.num_crtc;
>         total_objects += dev->mode_config.num_connector;
>         total_objects += dev->mode_config.num_encoder;
> +       total_objects += dev->mode_config.num_bridge;
>
>         group->id_list = kzalloc(total_objects * sizeof(uint32_t), GFP_KERNEL);
>         if (!group->id_list)
> @@ -1198,6 +1234,7 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
>         group->num_crtcs = 0;
>         group->num_connectors = 0;
>         group->num_encoders = 0;
> +       group->num_bridges = 0;
>         return 0;
>  }
>
> @@ -1207,6 +1244,7 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
>         struct drm_crtc *crtc;
>         struct drm_encoder *encoder;
>         struct drm_connector *connector;
> +       struct drm_bridge *bridge;
>         int ret;
>
>         if ((ret = drm_mode_group_init(dev, group)))
> @@ -1223,6 +1261,11 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
>                 group->id_list[group->num_crtcs + group->num_encoders +
>                                group->num_connectors++] = connector->base.id;
>
> +       list_for_each_entry(bridge, &dev->mode_config.bridge_list, head)
> +               group->id_list[group->num_crtcs + group->num_encoders +
> +                              group->num_connectors + group->num_bridges++] =
> +                                       bridge->base.id;
> +
>         return 0;
>  }
>  EXPORT_SYMBOL(drm_mode_group_init_legacy_group);
> @@ -3905,6 +3948,7 @@ void drm_mode_config_init(struct drm_device *dev)
>         INIT_LIST_HEAD(&dev->mode_config.fb_list);
>         INIT_LIST_HEAD(&dev->mode_config.crtc_list);
>         INIT_LIST_HEAD(&dev->mode_config.connector_list);
> +       INIT_LIST_HEAD(&dev->mode_config.bridge_list);
>         INIT_LIST_HEAD(&dev->mode_config.encoder_list);
>         INIT_LIST_HEAD(&dev->mode_config.property_list);
>         INIT_LIST_HEAD(&dev->mode_config.property_blob_list);
> @@ -3941,6 +3985,7 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>         struct drm_connector *connector, *ot;
>         struct drm_crtc *crtc, *ct;
>         struct drm_encoder *encoder, *enct;
> +       struct drm_bridge *bridge, *brt;
>         struct drm_framebuffer *fb, *fbt;
>         struct drm_property *property, *pt;
>         struct drm_property_blob *blob, *bt;
> @@ -3951,6 +3996,11 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>                 encoder->funcs->destroy(encoder);
>         }
>
> +       list_for_each_entry_safe(bridge, brt,
> +                                &dev->mode_config.bridge_list, head) {
> +               bridge->funcs->destroy(bridge);
> +       }
> +
>         list_for_each_entry_safe(connector, ot,
>                                  &dev->mode_config.connector_list, head) {
>                 connector->funcs->destroy(connector);
> diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
> index 6a64749..c722c3b 100644
> --- a/drivers/gpu/drm/drm_crtc_helper.c
> +++ b/drivers/gpu/drm/drm_crtc_helper.c
> @@ -257,10 +257,16 @@ drm_encoder_disable(struct drm_encoder *encoder)
>  {
>         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>
> +       if (encoder->bridge)
> +               encoder->bridge->funcs->disable(encoder->bridge);
> +
>         if (encoder_funcs->disable)
>                 (*encoder_funcs->disable)(encoder);
>         else
>                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
> +
> +       if (encoder->bridge)
> +               encoder->bridge->funcs->post_disable(encoder->bridge);
>  }
>
>  /**
> @@ -424,6 +430,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>
>                 if (encoder->crtc != crtc)
>                         continue;
> +
> +               if (encoder->bridge && encoder->bridge->funcs->mode_fixup) {
> +                       ret = encoder->bridge->funcs->mode_fixup(
> +                                       encoder->bridge, mode, adjusted_mode);
> +                       if (!ret) {
> +                               DRM_DEBUG_KMS("Bridge fixup failed\n");
> +                               goto done;
> +                       }
> +               }
> +
>                 encoder_funcs = encoder->helper_private;
>                 if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
>                                                       adjusted_mode))) {
> @@ -443,9 +459,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>
>                 if (encoder->crtc != crtc)
>                         continue;
> +
> +               if (encoder->bridge)
> +                       encoder->bridge->funcs->disable(encoder->bridge);
> +
>                 encoder_funcs = encoder->helper_private;
>                 /* Disable the encoders as the first thing we do. */
>                 encoder_funcs->prepare(encoder);
> +
> +               if (encoder->bridge)
> +                       encoder->bridge->funcs->post_disable(encoder->bridge);
>         }
>
>         drm_crtc_prepare_encoders(dev);
> @@ -469,6 +492,10 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>                         mode->base.id, mode->name);
>                 encoder_funcs = encoder->helper_private;
>                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
> +
> +               if (encoder->bridge && encoder->bridge->funcs->mode_set)
> +                       encoder->bridge->funcs->mode_set(encoder->bridge, mode,
> +                                       adjusted_mode);
>         }
>
>         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
> @@ -479,9 +506,14 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>                 if (encoder->crtc != crtc)
>                         continue;
>
> +               if (encoder->bridge)
> +                       encoder->bridge->funcs->pre_enable(encoder->bridge);
> +
>                 encoder_funcs = encoder->helper_private;
>                 encoder_funcs->commit(encoder);
>
> +               if (encoder->bridge)
> +                       encoder->bridge->funcs->enable(encoder->bridge);
>         }
>
>         /* Store real post-adjustment hardware mode. */
> @@ -830,6 +862,31 @@ static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
>         return dpms;
>  }
>
> +/* Helper which handles bridge ordering around encoder dpms */
> +static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
> +{
> +       struct drm_bridge *bridge = encoder->bridge;
> +       struct drm_encoder_helper_funcs *encoder_funcs;
> +
> +       if (bridge) {
> +               if (mode == DRM_MODE_DPMS_ON)
> +                       bridge->funcs->pre_enable(bridge);
> +               else
> +                       bridge->funcs->disable(bridge);
> +       }
> +
> +       encoder_funcs = encoder->helper_private;
> +       if (encoder_funcs->dpms)
> +               encoder_funcs->dpms(encoder, mode);
> +
> +       if (bridge) {
> +               if (mode == DRM_MODE_DPMS_ON)
> +                       bridge->funcs->enable(bridge);
> +               else
> +                       bridge->funcs->post_disable(bridge);
> +       }
> +}
> +
>  static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
>  {
>         int dpms = DRM_MODE_DPMS_OFF;
> @@ -857,7 +914,7 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>  {
>         struct drm_encoder *encoder = connector->encoder;
>         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
> -       int old_dpms;
> +       int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
>
>         if (mode == connector->dpms)
>                 return;
> @@ -865,6 +922,9 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>         old_dpms = connector->dpms;
>         connector->dpms = mode;
>
> +       if (encoder)
> +               encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
> +
>         /* from off to on, do crtc then encoder */
>         if (mode < old_dpms) {
>                 if (crtc) {
> @@ -873,22 +933,14 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>                                 (*crtc_funcs->dpms) (crtc,
>                                                      drm_helper_choose_crtc_dpms(crtc));
>                 }
> -               if (encoder) {
> -                       struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
> -                       if (encoder_funcs->dpms)
> -                               (*encoder_funcs->dpms) (encoder,
> -                                                       drm_helper_choose_encoder_dpms(encoder));
> -               }
> +               if (encoder)
> +                       drm_helper_encoder_dpms(encoder, encoder_dpms);
>         }
>
>         /* from on to off, do encoder then crtc */
>         if (mode > old_dpms) {
> -               if (encoder) {
> -                       struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
> -                       if (encoder_funcs->dpms)
> -                               (*encoder_funcs->dpms) (encoder,
> -                                                       drm_helper_choose_encoder_dpms(encoder));
> -               }
> +               if (encoder)
> +                       drm_helper_encoder_dpms(encoder, encoder_dpms);
>                 if (crtc) {
>                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
>                         if (crtc_funcs->dpms)
> @@ -924,9 +976,8 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
>  {
>         struct drm_crtc *crtc;
>         struct drm_encoder *encoder;
> -       struct drm_encoder_helper_funcs *encoder_funcs;
>         struct drm_crtc_helper_funcs *crtc_funcs;
> -       int ret;
> +       int ret, encoder_dpms;
>
>         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
>
> @@ -946,10 +997,10 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
>                                 if(encoder->crtc != crtc)
>                                         continue;
>
> -                               encoder_funcs = encoder->helper_private;
> -                               if (encoder_funcs->dpms)
> -                                       (*encoder_funcs->dpms) (encoder,
> -                                                               drm_helper_choose_encoder_dpms(encoder));
> +                               encoder_dpms = drm_helper_choose_encoder_dpms(
> +                                                       encoder);
> +
> +                               drm_helper_encoder_dpms(encoder, encoder_dpms);
>                         }
>
>                         crtc_funcs = crtc->helper_private;
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index fa12a2f..a26d3d9 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -49,6 +49,7 @@ struct drm_clip_rect;
>  #define DRM_MODE_OBJECT_FB 0xfbfbfbfb
>  #define DRM_MODE_OBJECT_BLOB 0xbbbbbbbb
>  #define DRM_MODE_OBJECT_PLANE 0xeeeeeeee
> +#define DRM_MODE_OBJECT_BRIDGE 0xbdbdbdbd
>
>  struct drm_mode_object {
>         uint32_t id;
> @@ -305,6 +306,7 @@ struct drm_connector;
>  struct drm_encoder;
>  struct drm_pending_vblank_event;
>  struct drm_plane;
> +struct drm_bridge;
>
>  /**
>   * drm_crtc_funcs - control CRTCs for a given device
> @@ -507,6 +509,7 @@ struct drm_encoder_funcs {
>   * @possible_crtcs: bitmask of potential CRTC bindings
>   * @possible_clones: bitmask of potential sibling encoders for cloning
>   * @crtc: currently bound CRTC
> + * @bridge: bridge associated to the encoder
>   * @funcs: control functions
>   * @helper_private: mid-layer private data
>   *
> @@ -523,6 +526,7 @@ struct drm_encoder {
>         uint32_t possible_clones;
>
>         struct drm_crtc *crtc;
> +       struct drm_bridge *bridge;
>         const struct drm_encoder_funcs *funcs;
>         void *helper_private;
>  };
> @@ -683,6 +687,48 @@ struct drm_plane {
>  };
>
>  /**
> + * drm_bridge_funcs - drm_bridge control functions
> + * @mode_fixup: Try to fixup (or reject entirely) proposed mode for this bridge
> + * @disable: Called right before encoder prepare, disables the bridge
> + * @post_disable: Called right after encoder prepare, for lockstepped disable
> + * @mode_set: Set this mode to the bridge
> + * @pre_enable: Called right before encoder commit, for lockstepped commit
> + * @enable: Called right after encoder commit, enables the bridge
> + * @destroy: make object go away
> + */
> +struct drm_bridge_funcs {
> +       bool (*mode_fixup)(struct drm_bridge *bridge,
> +                          const struct drm_display_mode *mode,
> +                          struct drm_display_mode *adjusted_mode);
> +       void (*disable)(struct drm_bridge *bridge);
> +       void (*post_disable)(struct drm_bridge *bridge);
> +       void (*mode_set)(struct drm_bridge *bridge,
> +                        struct drm_display_mode *mode,
> +                        struct drm_display_mode *adjusted_mode);
> +       void (*pre_enable)(struct drm_bridge *bridge);
> +       void (*enable)(struct drm_bridge *bridge);
> +       void (*destroy)(struct drm_bridge *bridge);
> +};
> +
> +/**
> + * drm_bridge - central DRM bridge control structure
> + * @dev: DRM device this bridge belongs to
> + * @head: list management
> + * @base: base mode object
> + * @funcs: control functions
> + * @driver_private: pointer to the bridge driver's internal context
> + */
> +struct drm_bridge {
> +       struct drm_device *dev;
> +       struct list_head head;
> +
> +       struct drm_mode_object base;
> +
> +       const struct drm_bridge_funcs *funcs;
> +       void *driver_private;
> +};
> +
> +/**
>   * drm_mode_set - new values for a CRTC config change
>   * @head: list management
>   * @fb: framebuffer to use for new config
> @@ -742,6 +788,7 @@ struct drm_mode_group {
>         uint32_t num_crtcs;
>         uint32_t num_encoders;
>         uint32_t num_connectors;
> +       uint32_t num_bridges;
>
>         /* list of object IDs for this group */
>         uint32_t *id_list;
> @@ -756,6 +803,8 @@ struct drm_mode_group {
>   * @fb_list: list of framebuffers available
>   * @num_connector: number of connectors on this device
>   * @connector_list: list of connector objects
> + * @num_bridge: number of bridges on this device
> + * @bridge_list: list of bridge objects
>   * @num_encoder: number of encoders on this device
>   * @encoder_list: list of encoder objects
>   * @num_crtc: number of CRTCs on this device
> @@ -793,6 +842,8 @@ struct drm_mode_config {
>
>         int num_connector;
>         struct list_head connector_list;
> +       int num_bridge;
> +       struct list_head bridge_list;
>         int num_encoder;
>         struct list_head encoder_list;
>         int num_plane;
> @@ -878,6 +929,10 @@ extern void drm_connector_cleanup(struct drm_connector *connector);
>  /* helper to unplug all connectors from sysfs for device */
>  extern void drm_connector_unplug_all(struct drm_device *dev);
>
> +extern int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
> +                          const struct drm_bridge_funcs *funcs);
> +extern void drm_bridge_cleanup(struct drm_bridge *bridge);
> +
>  extern int drm_encoder_init(struct drm_device *dev,
>                             struct drm_encoder *encoder,
>                             const struct drm_encoder_funcs *funcs,
> --
> 1.8.3
>

Re: [PATCH v2 1/2] drm: Add drm_bridge

[Rob Clark]

On Thu, Aug 29, 2013 at 11:59 AM, Sean Paul <seanpaul@chromium.org> wrote:
> On Wed, Aug 14, 2013 at 4:47 PM, Sean Paul <seanpaul@chromium.org> wrote:
>> This patch adds the notion of a drm_bridge. A bridge is a chained
>> device which hangs off an encoder. The drm driver using the bridge
>> should provide the association between encoder and bridge. Once a
>> bridge is associated with an encoder, it will participate in mode
>> set, and dpms (via the enable/disable hooks).
>>
>
> Friendly ping. Any feedback?

It looks good to me, although unfortunately I've not had a chance to
rebase on this version.  I'll try to make some time to do that in the
next few days.

BR,
-R

> Sean
>
>
>> Signed-off-by: Sean Paul <seanpaul@chromium.org>
>> ---
>>  drivers/gpu/drm/drm_crtc.c        | 50 ++++++++++++++++++++++
>>  drivers/gpu/drm/drm_crtc_helper.c | 89 ++++++++++++++++++++++++++++++---------
>>  include/drm/drm_crtc.h            | 55 ++++++++++++++++++++++++
>>  3 files changed, 175 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
>> index fc83bb9..0311e2b 100644
>> --- a/drivers/gpu/drm/drm_crtc.c
>> +++ b/drivers/gpu/drm/drm_crtc.c
>> @@ -781,6 +781,41 @@ void drm_connector_unplug_all(struct drm_device *dev)
>>  }
>>  EXPORT_SYMBOL(drm_connector_unplug_all);
>>
>> +int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
>> +               const struct drm_bridge_funcs *funcs)
>> +{
>> +       int ret;
>> +
>> +       drm_modeset_lock_all(dev);
>> +
>> +       ret = drm_mode_object_get(dev, &bridge->base, DRM_MODE_OBJECT_BRIDGE);
>> +       if (ret)
>> +               goto out;
>> +
>> +       bridge->dev = dev;
>> +       bridge->funcs = funcs;
>> +
>> +       list_add_tail(&bridge->head, &dev->mode_config.bridge_list);
>> +       dev->mode_config.num_bridge++;
>> +
>> + out:
>> +       drm_modeset_unlock_all(dev);
>> +       return ret;
>> +}
>> +EXPORT_SYMBOL(drm_bridge_init);
>> +
>> +void drm_bridge_cleanup(struct drm_bridge *bridge)
>> +{
>> +       struct drm_device *dev = bridge->dev;
>> +
>> +       drm_modeset_lock_all(dev);
>> +       drm_mode_object_put(dev, &bridge->base);
>> +       list_del(&bridge->head);
>> +       dev->mode_config.num_bridge--;
>> +       drm_modeset_unlock_all(dev);
>> +}
>> +EXPORT_SYMBOL(drm_bridge_cleanup);
>> +
>>  int drm_encoder_init(struct drm_device *dev,
>>                       struct drm_encoder *encoder,
>>                       const struct drm_encoder_funcs *funcs,
>> @@ -1190,6 +1225,7 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
>>         total_objects += dev->mode_config.num_crtc;
>>         total_objects += dev->mode_config.num_connector;
>>         total_objects += dev->mode_config.num_encoder;
>> +       total_objects += dev->mode_config.num_bridge;
>>
>>         group->id_list = kzalloc(total_objects * sizeof(uint32_t), GFP_KERNEL);
>>         if (!group->id_list)
>> @@ -1198,6 +1234,7 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
>>         group->num_crtcs = 0;
>>         group->num_connectors = 0;
>>         group->num_encoders = 0;
>> +       group->num_bridges = 0;
>>         return 0;
>>  }
>>
>> @@ -1207,6 +1244,7 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
>>         struct drm_crtc *crtc;
>>         struct drm_encoder *encoder;
>>         struct drm_connector *connector;
>> +       struct drm_bridge *bridge;
>>         int ret;
>>
>>         if ((ret = drm_mode_group_init(dev, group)))
>> @@ -1223,6 +1261,11 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
>>                 group->id_list[group->num_crtcs + group->num_encoders +
>>                                group->num_connectors++] = connector->base.id;
>>
>> +       list_for_each_entry(bridge, &dev->mode_config.bridge_list, head)
>> +               group->id_list[group->num_crtcs + group->num_encoders +
>> +                              group->num_connectors + group->num_bridges++] =
>> +                                       bridge->base.id;
>> +
>>         return 0;
>>  }
>>  EXPORT_SYMBOL(drm_mode_group_init_legacy_group);
>> @@ -3905,6 +3948,7 @@ void drm_mode_config_init(struct drm_device *dev)
>>         INIT_LIST_HEAD(&dev->mode_config.fb_list);
>>         INIT_LIST_HEAD(&dev->mode_config.crtc_list);
>>         INIT_LIST_HEAD(&dev->mode_config.connector_list);
>> +       INIT_LIST_HEAD(&dev->mode_config.bridge_list);
>>         INIT_LIST_HEAD(&dev->mode_config.encoder_list);
>>         INIT_LIST_HEAD(&dev->mode_config.property_list);
>>         INIT_LIST_HEAD(&dev->mode_config.property_blob_list);
>> @@ -3941,6 +3985,7 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>>         struct drm_connector *connector, *ot;
>>         struct drm_crtc *crtc, *ct;
>>         struct drm_encoder *encoder, *enct;
>> +       struct drm_bridge *bridge, *brt;
>>         struct drm_framebuffer *fb, *fbt;
>>         struct drm_property *property, *pt;
>>         struct drm_property_blob *blob, *bt;
>> @@ -3951,6 +3996,11 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>>                 encoder->funcs->destroy(encoder);
>>         }
>>
>> +       list_for_each_entry_safe(bridge, brt,
>> +                                &dev->mode_config.bridge_list, head) {
>> +               bridge->funcs->destroy(bridge);
>> +       }
>> +
>>         list_for_each_entry_safe(connector, ot,
>>                                  &dev->mode_config.connector_list, head) {
>>                 connector->funcs->destroy(connector);
>> diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
>> index 6a64749..c722c3b 100644
>> --- a/drivers/gpu/drm/drm_crtc_helper.c
>> +++ b/drivers/gpu/drm/drm_crtc_helper.c
>> @@ -257,10 +257,16 @@ drm_encoder_disable(struct drm_encoder *encoder)
>>  {
>>         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>>
>> +       if (encoder->bridge)
>> +               encoder->bridge->funcs->disable(encoder->bridge);
>> +
>>         if (encoder_funcs->disable)
>>                 (*encoder_funcs->disable)(encoder);
>>         else
>>                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
>> +
>> +       if (encoder->bridge)
>> +               encoder->bridge->funcs->post_disable(encoder->bridge);
>>  }
>>
>>  /**
>> @@ -424,6 +430,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>
>>                 if (encoder->crtc != crtc)
>>                         continue;
>> +
>> +               if (encoder->bridge && encoder->bridge->funcs->mode_fixup) {
>> +                       ret = encoder->bridge->funcs->mode_fixup(
>> +                                       encoder->bridge, mode, adjusted_mode);
>> +                       if (!ret) {
>> +                               DRM_DEBUG_KMS("Bridge fixup failed\n");
>> +                               goto done;
>> +                       }
>> +               }
>> +
>>                 encoder_funcs = encoder->helper_private;
>>                 if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
>>                                                       adjusted_mode))) {
>> @@ -443,9 +459,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>
>>                 if (encoder->crtc != crtc)
>>                         continue;
>> +
>> +               if (encoder->bridge)
>> +                       encoder->bridge->funcs->disable(encoder->bridge);
>> +
>>                 encoder_funcs = encoder->helper_private;
>>                 /* Disable the encoders as the first thing we do. */
>>                 encoder_funcs->prepare(encoder);
>> +
>> +               if (encoder->bridge)
>> +                       encoder->bridge->funcs->post_disable(encoder->bridge);
>>         }
>>
>>         drm_crtc_prepare_encoders(dev);
>> @@ -469,6 +492,10 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>                         mode->base.id, mode->name);
>>                 encoder_funcs = encoder->helper_private;
>>                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
>> +
>> +               if (encoder->bridge && encoder->bridge->funcs->mode_set)
>> +                       encoder->bridge->funcs->mode_set(encoder->bridge, mode,
>> +                                       adjusted_mode);
>>         }
>>
>>         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
>> @@ -479,9 +506,14 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>                 if (encoder->crtc != crtc)
>>                         continue;
>>
>> +               if (encoder->bridge)
>> +                       encoder->bridge->funcs->pre_enable(encoder->bridge);
>> +
>>                 encoder_funcs = encoder->helper_private;
>>                 encoder_funcs->commit(encoder);
>>
>> +               if (encoder->bridge)
>> +                       encoder->bridge->funcs->enable(encoder->bridge);
>>         }
>>
>>         /* Store real post-adjustment hardware mode. */
>> @@ -830,6 +862,31 @@ static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
>>         return dpms;
>>  }
>>
>> +/* Helper which handles bridge ordering around encoder dpms */
>> +static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
>> +{
>> +       struct drm_bridge *bridge = encoder->bridge;
>> +       struct drm_encoder_helper_funcs *encoder_funcs;
>> +
>> +       if (bridge) {
>> +               if (mode == DRM_MODE_DPMS_ON)
>> +                       bridge->funcs->pre_enable(bridge);
>> +               else
>> +                       bridge->funcs->disable(bridge);
>> +       }
>> +
>> +       encoder_funcs = encoder->helper_private;
>> +       if (encoder_funcs->dpms)
>> +               encoder_funcs->dpms(encoder, mode);
>> +
>> +       if (bridge) {
>> +               if (mode == DRM_MODE_DPMS_ON)
>> +                       bridge->funcs->enable(bridge);
>> +               else
>> +                       bridge->funcs->post_disable(bridge);
>> +       }
>> +}
>> +
>>  static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
>>  {
>>         int dpms = DRM_MODE_DPMS_OFF;
>> @@ -857,7 +914,7 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>>  {
>>         struct drm_encoder *encoder = connector->encoder;
>>         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
>> -       int old_dpms;
>> +       int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
>>
>>         if (mode == connector->dpms)
>>                 return;
>> @@ -865,6 +922,9 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>>         old_dpms = connector->dpms;
>>         connector->dpms = mode;
>>
>> +       if (encoder)
>> +               encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
>> +
>>         /* from off to on, do crtc then encoder */
>>         if (mode < old_dpms) {
>>                 if (crtc) {
>> @@ -873,22 +933,14 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>>                                 (*crtc_funcs->dpms) (crtc,
>>                                                      drm_helper_choose_crtc_dpms(crtc));
>>                 }
>> -               if (encoder) {
>> -                       struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>> -                       if (encoder_funcs->dpms)
>> -                               (*encoder_funcs->dpms) (encoder,
>> -                                                       drm_helper_choose_encoder_dpms(encoder));
>> -               }
>> +               if (encoder)
>> +                       drm_helper_encoder_dpms(encoder, encoder_dpms);
>>         }
>>
>>         /* from on to off, do encoder then crtc */
>>         if (mode > old_dpms) {
>> -               if (encoder) {
>> -                       struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>> -                       if (encoder_funcs->dpms)
>> -                               (*encoder_funcs->dpms) (encoder,
>> -                                                       drm_helper_choose_encoder_dpms(encoder));
>> -               }
>> +               if (encoder)
>> +                       drm_helper_encoder_dpms(encoder, encoder_dpms);
>>                 if (crtc) {
>>                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
>>                         if (crtc_funcs->dpms)
>> @@ -924,9 +976,8 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
>>  {
>>         struct drm_crtc *crtc;
>>         struct drm_encoder *encoder;
>> -       struct drm_encoder_helper_funcs *encoder_funcs;
>>         struct drm_crtc_helper_funcs *crtc_funcs;
>> -       int ret;
>> +       int ret, encoder_dpms;
>>
>>         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
>>
>> @@ -946,10 +997,10 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
>>                                 if(encoder->crtc != crtc)
>>                                         continue;
>>
>> -                               encoder_funcs = encoder->helper_private;
>> -                               if (encoder_funcs->dpms)
>> -                                       (*encoder_funcs->dpms) (encoder,
>> -                                                               drm_helper_choose_encoder_dpms(encoder));
>> +                               encoder_dpms = drm_helper_choose_encoder_dpms(
>> +                                                       encoder);
>> +
>> +                               drm_helper_encoder_dpms(encoder, encoder_dpms);
>>                         }
>>
>>                         crtc_funcs = crtc->helper_private;
>> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
>> index fa12a2f..a26d3d9 100644
>> --- a/include/drm/drm_crtc.h
>> +++ b/include/drm/drm_crtc.h
>> @@ -49,6 +49,7 @@ struct drm_clip_rect;
>>  #define DRM_MODE_OBJECT_FB 0xfbfbfbfb
>>  #define DRM_MODE_OBJECT_BLOB 0xbbbbbbbb
>>  #define DRM_MODE_OBJECT_PLANE 0xeeeeeeee
>> +#define DRM_MODE_OBJECT_BRIDGE 0xbdbdbdbd
>>
>>  struct drm_mode_object {
>>         uint32_t id;
>> @@ -305,6 +306,7 @@ struct drm_connector;
>>  struct drm_encoder;
>>  struct drm_pending_vblank_event;
>>  struct drm_plane;
>> +struct drm_bridge;
>>
>>  /**
>>   * drm_crtc_funcs - control CRTCs for a given device
>> @@ -507,6 +509,7 @@ struct drm_encoder_funcs {
>>   * @possible_crtcs: bitmask of potential CRTC bindings
>>   * @possible_clones: bitmask of potential sibling encoders for cloning
>>   * @crtc: currently bound CRTC
>> + * @bridge: bridge associated to the encoder
>>   * @funcs: control functions
>>   * @helper_private: mid-layer private data
>>   *
>> @@ -523,6 +526,7 @@ struct drm_encoder {
>>         uint32_t possible_clones;
>>
>>         struct drm_crtc *crtc;
>> +       struct drm_bridge *bridge;
>>         const struct drm_encoder_funcs *funcs;
>>         void *helper_private;
>>  };
>> @@ -683,6 +687,48 @@ struct drm_plane {
>>  };
>>
>>  /**
>> + * drm_bridge_funcs - drm_bridge control functions
>> + * @mode_fixup: Try to fixup (or reject entirely) proposed mode for this bridge
>> + * @disable: Called right before encoder prepare, disables the bridge
>> + * @post_disable: Called right after encoder prepare, for lockstepped disable
>> + * @mode_set: Set this mode to the bridge
>> + * @pre_enable: Called right before encoder commit, for lockstepped commit
>> + * @enable: Called right after encoder commit, enables the bridge
>> + * @destroy: make object go away
>> + */
>> +struct drm_bridge_funcs {
>> +       bool (*mode_fixup)(struct drm_bridge *bridge,
>> +                          const struct drm_display_mode *mode,
>> +                          struct drm_display_mode *adjusted_mode);
>> +       void (*disable)(struct drm_bridge *bridge);
>> +       void (*post_disable)(struct drm_bridge *bridge);
>> +       void (*mode_set)(struct drm_bridge *bridge,
>> +                        struct drm_display_mode *mode,
>> +                        struct drm_display_mode *adjusted_mode);
>> +       void (*pre_enable)(struct drm_bridge *bridge);
>> +       void (*enable)(struct drm_bridge *bridge);
>> +       void (*destroy)(struct drm_bridge *bridge);
>> +};
>> +
>> +/**
>> + * drm_bridge - central DRM bridge control structure
>> + * @dev: DRM device this bridge belongs to
>> + * @head: list management
>> + * @base: base mode object
>> + * @funcs: control functions
>> + * @driver_private: pointer to the bridge driver's internal context
>> + */
>> +struct drm_bridge {
>> +       struct drm_device *dev;
>> +       struct list_head head;
>> +
>> +       struct drm_mode_object base;
>> +
>> +       const struct drm_bridge_funcs *funcs;
>> +       void *driver_private;
>> +};
>> +
>> +/**
>>   * drm_mode_set - new values for a CRTC config change
>>   * @head: list management
>>   * @fb: framebuffer to use for new config
>> @@ -742,6 +788,7 @@ struct drm_mode_group {
>>         uint32_t num_crtcs;
>>         uint32_t num_encoders;
>>         uint32_t num_connectors;
>> +       uint32_t num_bridges;
>>
>>         /* list of object IDs for this group */
>>         uint32_t *id_list;
>> @@ -756,6 +803,8 @@ struct drm_mode_group {
>>   * @fb_list: list of framebuffers available
>>   * @num_connector: number of connectors on this device
>>   * @connector_list: list of connector objects
>> + * @num_bridge: number of bridges on this device
>> + * @bridge_list: list of bridge objects
>>   * @num_encoder: number of encoders on this device
>>   * @encoder_list: list of encoder objects
>>   * @num_crtc: number of CRTCs on this device
>> @@ -793,6 +842,8 @@ struct drm_mode_config {
>>
>>         int num_connector;
>>         struct list_head connector_list;
>> +       int num_bridge;
>> +       struct list_head bridge_list;
>>         int num_encoder;
>>         struct list_head encoder_list;
>>         int num_plane;
>> @@ -878,6 +929,10 @@ extern void drm_connector_cleanup(struct drm_connector *connector);
>>  /* helper to unplug all connectors from sysfs for device */
>>  extern void drm_connector_unplug_all(struct drm_device *dev);
>>
>> +extern int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
>> +                          const struct drm_bridge_funcs *funcs);
>> +extern void drm_bridge_cleanup(struct drm_bridge *bridge);
>> +
>>  extern int drm_encoder_init(struct drm_device *dev,
>>                             struct drm_encoder *encoder,
>>                             const struct drm_encoder_funcs *funcs,
>> --
>> 1.8.3
>>

Re: [PATCH v2 1/2] drm: Add drm_bridge

[Daniel Vetter]

On Thu, Aug 29, 2013 at 12:13:16PM -0400, Rob Clark wrote:
> On Thu, Aug 29, 2013 at 11:59 AM, Sean Paul <seanpaul@chromium.org> wrote:
> > On Wed, Aug 14, 2013 at 4:47 PM, Sean Paul <seanpaul@chromium.org> wrote:
> >> This patch adds the notion of a drm_bridge. A bridge is a chained
> >> device which hangs off an encoder. The drm driver using the bridge
> >> should provide the association between encoder and bridge. Once a
> >> bridge is associated with an encoder, it will participate in mode
> >> set, and dpms (via the enable/disable hooks).
> >>
> >
> > Friendly ping. Any feedback?
> 
> It looks good to me, although unfortunately I've not had a chance to
> rebase on this version.  I'll try to make some time to do that in the
> next few days.

Looks good to me, no more bikesheds from my side. I kinda wanted to port
over some of the stuff we have in drm/i915, but I guess that won't happen
anytime soon. Imo this can go in as soon as we have an in-tree user ready.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH v2 1/2] drm: Add drm_bridge

[Rob Clark]

On Wed, Aug 14, 2013 at 4:47 PM, Sean Paul <seanpaul@chromium.org> wrote:
> This patch adds the notion of a drm_bridge. A bridge is a chained
> device which hangs off an encoder. The drm driver using the bridge
> should provide the association between encoder and bridge. Once a
> bridge is associated with an encoder, it will participate in mode
> set, and dpms (via the enable/disable hooks).
>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>

Ok, I've had a chance to rebase my msm drm-bridge patch on top of this
latest version (which I'll be sending in a couple of minutes)

Reviewed-by: Rob Clark <robdclark@gmail.com>


> ---
>  drivers/gpu/drm/drm_crtc.c        | 50 ++++++++++++++++++++++
>  drivers/gpu/drm/drm_crtc_helper.c | 89 ++++++++++++++++++++++++++++++---------
>  include/drm/drm_crtc.h            | 55 ++++++++++++++++++++++++
>  3 files changed, 175 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index fc83bb9..0311e2b 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -781,6 +781,41 @@ void drm_connector_unplug_all(struct drm_device *dev)
>  }
>  EXPORT_SYMBOL(drm_connector_unplug_all);
>
> +int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
> +               const struct drm_bridge_funcs *funcs)
> +{
> +       int ret;
> +
> +       drm_modeset_lock_all(dev);
> +
> +       ret = drm_mode_object_get(dev, &bridge->base, DRM_MODE_OBJECT_BRIDGE);
> +       if (ret)
> +               goto out;
> +
> +       bridge->dev = dev;
> +       bridge->funcs = funcs;
> +
> +       list_add_tail(&bridge->head, &dev->mode_config.bridge_list);
> +       dev->mode_config.num_bridge++;
> +
> + out:
> +       drm_modeset_unlock_all(dev);
> +       return ret;
> +}
> +EXPORT_SYMBOL(drm_bridge_init);
> +
> +void drm_bridge_cleanup(struct drm_bridge *bridge)
> +{
> +       struct drm_device *dev = bridge->dev;
> +
> +       drm_modeset_lock_all(dev);
> +       drm_mode_object_put(dev, &bridge->base);
> +       list_del(&bridge->head);
> +       dev->mode_config.num_bridge--;
> +       drm_modeset_unlock_all(dev);
> +}
> +EXPORT_SYMBOL(drm_bridge_cleanup);
> +
>  int drm_encoder_init(struct drm_device *dev,
>                       struct drm_encoder *encoder,
>                       const struct drm_encoder_funcs *funcs,
> @@ -1190,6 +1225,7 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
>         total_objects += dev->mode_config.num_crtc;
>         total_objects += dev->mode_config.num_connector;
>         total_objects += dev->mode_config.num_encoder;
> +       total_objects += dev->mode_config.num_bridge;
>
>         group->id_list = kzalloc(total_objects * sizeof(uint32_t), GFP_KERNEL);
>         if (!group->id_list)
> @@ -1198,6 +1234,7 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
>         group->num_crtcs = 0;
>         group->num_connectors = 0;
>         group->num_encoders = 0;
> +       group->num_bridges = 0;
>         return 0;
>  }
>
> @@ -1207,6 +1244,7 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
>         struct drm_crtc *crtc;
>         struct drm_encoder *encoder;
>         struct drm_connector *connector;
> +       struct drm_bridge *bridge;
>         int ret;
>
>         if ((ret = drm_mode_group_init(dev, group)))
> @@ -1223,6 +1261,11 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
>                 group->id_list[group->num_crtcs + group->num_encoders +
>                                group->num_connectors++] = connector->base.id;
>
> +       list_for_each_entry(bridge, &dev->mode_config.bridge_list, head)
> +               group->id_list[group->num_crtcs + group->num_encoders +
> +                              group->num_connectors + group->num_bridges++] =
> +                                       bridge->base.id;
> +
>         return 0;
>  }
>  EXPORT_SYMBOL(drm_mode_group_init_legacy_group);
> @@ -3905,6 +3948,7 @@ void drm_mode_config_init(struct drm_device *dev)
>         INIT_LIST_HEAD(&dev->mode_config.fb_list);
>         INIT_LIST_HEAD(&dev->mode_config.crtc_list);
>         INIT_LIST_HEAD(&dev->mode_config.connector_list);
> +       INIT_LIST_HEAD(&dev->mode_config.bridge_list);
>         INIT_LIST_HEAD(&dev->mode_config.encoder_list);
>         INIT_LIST_HEAD(&dev->mode_config.property_list);
>         INIT_LIST_HEAD(&dev->mode_config.property_blob_list);
> @@ -3941,6 +3985,7 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>         struct drm_connector *connector, *ot;
>         struct drm_crtc *crtc, *ct;
>         struct drm_encoder *encoder, *enct;
> +       struct drm_bridge *bridge, *brt;
>         struct drm_framebuffer *fb, *fbt;
>         struct drm_property *property, *pt;
>         struct drm_property_blob *blob, *bt;
> @@ -3951,6 +3996,11 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>                 encoder->funcs->destroy(encoder);
>         }
>
> +       list_for_each_entry_safe(bridge, brt,
> +                                &dev->mode_config.bridge_list, head) {
> +               bridge->funcs->destroy(bridge);
> +       }
> +
>         list_for_each_entry_safe(connector, ot,
>                                  &dev->mode_config.connector_list, head) {
>                 connector->funcs->destroy(connector);
> diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
> index 6a64749..c722c3b 100644
> --- a/drivers/gpu/drm/drm_crtc_helper.c
> +++ b/drivers/gpu/drm/drm_crtc_helper.c
> @@ -257,10 +257,16 @@ drm_encoder_disable(struct drm_encoder *encoder)
>  {
>         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>
> +       if (encoder->bridge)
> +               encoder->bridge->funcs->disable(encoder->bridge);
> +
>         if (encoder_funcs->disable)
>                 (*encoder_funcs->disable)(encoder);
>         else
>                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
> +
> +       if (encoder->bridge)
> +               encoder->bridge->funcs->post_disable(encoder->bridge);
>  }
>
>  /**
> @@ -424,6 +430,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>
>                 if (encoder->crtc != crtc)
>                         continue;
> +
> +               if (encoder->bridge && encoder->bridge->funcs->mode_fixup) {
> +                       ret = encoder->bridge->funcs->mode_fixup(
> +                                       encoder->bridge, mode, adjusted_mode);
> +                       if (!ret) {
> +                               DRM_DEBUG_KMS("Bridge fixup failed\n");
> +                               goto done;
> +                       }
> +               }
> +
>                 encoder_funcs = encoder->helper_private;
>                 if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
>                                                       adjusted_mode))) {
> @@ -443,9 +459,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>
>                 if (encoder->crtc != crtc)
>                         continue;
> +
> +               if (encoder->bridge)
> +                       encoder->bridge->funcs->disable(encoder->bridge);
> +
>                 encoder_funcs = encoder->helper_private;
>                 /* Disable the encoders as the first thing we do. */
>                 encoder_funcs->prepare(encoder);
> +
> +               if (encoder->bridge)
> +                       encoder->bridge->funcs->post_disable(encoder->bridge);
>         }
>
>         drm_crtc_prepare_encoders(dev);
> @@ -469,6 +492,10 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>                         mode->base.id, mode->name);
>                 encoder_funcs = encoder->helper_private;
>                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
> +
> +               if (encoder->bridge && encoder->bridge->funcs->mode_set)
> +                       encoder->bridge->funcs->mode_set(encoder->bridge, mode,
> +                                       adjusted_mode);
>         }
>
>         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
> @@ -479,9 +506,14 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>                 if (encoder->crtc != crtc)
>                         continue;
>
> +               if (encoder->bridge)
> +                       encoder->bridge->funcs->pre_enable(encoder->bridge);
> +
>                 encoder_funcs = encoder->helper_private;
>                 encoder_funcs->commit(encoder);
>
> +               if (encoder->bridge)
> +                       encoder->bridge->funcs->enable(encoder->bridge);
>         }
>
>         /* Store real post-adjustment hardware mode. */
> @@ -830,6 +862,31 @@ static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
>         return dpms;
>  }
>
> +/* Helper which handles bridge ordering around encoder dpms */
> +static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
> +{
> +       struct drm_bridge *bridge = encoder->bridge;
> +       struct drm_encoder_helper_funcs *encoder_funcs;
> +
> +       if (bridge) {
> +               if (mode == DRM_MODE_DPMS_ON)
> +                       bridge->funcs->pre_enable(bridge);
> +               else
> +                       bridge->funcs->disable(bridge);
> +       }
> +
> +       encoder_funcs = encoder->helper_private;
> +       if (encoder_funcs->dpms)
> +               encoder_funcs->dpms(encoder, mode);
> +
> +       if (bridge) {
> +               if (mode == DRM_MODE_DPMS_ON)
> +                       bridge->funcs->enable(bridge);
> +               else
> +                       bridge->funcs->post_disable(bridge);
> +       }
> +}
> +
>  static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
>  {
>         int dpms = DRM_MODE_DPMS_OFF;
> @@ -857,7 +914,7 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>  {
>         struct drm_encoder *encoder = connector->encoder;
>         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
> -       int old_dpms;
> +       int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
>
>         if (mode == connector->dpms)
>                 return;
> @@ -865,6 +922,9 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>         old_dpms = connector->dpms;
>         connector->dpms = mode;
>
> +       if (encoder)
> +               encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
> +
>         /* from off to on, do crtc then encoder */
>         if (mode < old_dpms) {
>                 if (crtc) {
> @@ -873,22 +933,14 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>                                 (*crtc_funcs->dpms) (crtc,
>                                                      drm_helper_choose_crtc_dpms(crtc));
>                 }
> -               if (encoder) {
> -                       struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
> -                       if (encoder_funcs->dpms)
> -                               (*encoder_funcs->dpms) (encoder,
> -                                                       drm_helper_choose_encoder_dpms(encoder));
> -               }
> +               if (encoder)
> +                       drm_helper_encoder_dpms(encoder, encoder_dpms);
>         }
>
>         /* from on to off, do encoder then crtc */
>         if (mode > old_dpms) {
> -               if (encoder) {
> -                       struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
> -                       if (encoder_funcs->dpms)
> -                               (*encoder_funcs->dpms) (encoder,
> -                                                       drm_helper_choose_encoder_dpms(encoder));
> -               }
> +               if (encoder)
> +                       drm_helper_encoder_dpms(encoder, encoder_dpms);
>                 if (crtc) {
>                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
>                         if (crtc_funcs->dpms)
> @@ -924,9 +976,8 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
>  {
>         struct drm_crtc *crtc;
>         struct drm_encoder *encoder;
> -       struct drm_encoder_helper_funcs *encoder_funcs;
>         struct drm_crtc_helper_funcs *crtc_funcs;
> -       int ret;
> +       int ret, encoder_dpms;
>
>         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
>
> @@ -946,10 +997,10 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
>                                 if(encoder->crtc != crtc)
>                                         continue;
>
> -                               encoder_funcs = encoder->helper_private;
> -                               if (encoder_funcs->dpms)
> -                                       (*encoder_funcs->dpms) (encoder,
> -                                                               drm_helper_choose_encoder_dpms(encoder));
> +                               encoder_dpms = drm_helper_choose_encoder_dpms(
> +                                                       encoder);
> +
> +                               drm_helper_encoder_dpms(encoder, encoder_dpms);
>                         }
>
>                         crtc_funcs = crtc->helper_private;
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index fa12a2f..a26d3d9 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -49,6 +49,7 @@ struct drm_clip_rect;
>  #define DRM_MODE_OBJECT_FB 0xfbfbfbfb
>  #define DRM_MODE_OBJECT_BLOB 0xbbbbbbbb
>  #define DRM_MODE_OBJECT_PLANE 0xeeeeeeee
> +#define DRM_MODE_OBJECT_BRIDGE 0xbdbdbdbd
>
>  struct drm_mode_object {
>         uint32_t id;
> @@ -305,6 +306,7 @@ struct drm_connector;
>  struct drm_encoder;
>  struct drm_pending_vblank_event;
>  struct drm_plane;
> +struct drm_bridge;
>
>  /**
>   * drm_crtc_funcs - control CRTCs for a given device
> @@ -507,6 +509,7 @@ struct drm_encoder_funcs {
>   * @possible_crtcs: bitmask of potential CRTC bindings
>   * @possible_clones: bitmask of potential sibling encoders for cloning
>   * @crtc: currently bound CRTC
> + * @bridge: bridge associated to the encoder
>   * @funcs: control functions
>   * @helper_private: mid-layer private data
>   *
> @@ -523,6 +526,7 @@ struct drm_encoder {
>         uint32_t possible_clones;
>
>         struct drm_crtc *crtc;
> +       struct drm_bridge *bridge;
>         const struct drm_encoder_funcs *funcs;
>         void *helper_private;
>  };
> @@ -683,6 +687,48 @@ struct drm_plane {
>  };
>
>  /**
> + * drm_bridge_funcs - drm_bridge control functions
> + * @mode_fixup: Try to fixup (or reject entirely) proposed mode for this bridge
> + * @disable: Called right before encoder prepare, disables the bridge
> + * @post_disable: Called right after encoder prepare, for lockstepped disable
> + * @mode_set: Set this mode to the bridge
> + * @pre_enable: Called right before encoder commit, for lockstepped commit
> + * @enable: Called right after encoder commit, enables the bridge
> + * @destroy: make object go away
> + */
> +struct drm_bridge_funcs {
> +       bool (*mode_fixup)(struct drm_bridge *bridge,
> +                          const struct drm_display_mode *mode,
> +                          struct drm_display_mode *adjusted_mode);
> +       void (*disable)(struct drm_bridge *bridge);
> +       void (*post_disable)(struct drm_bridge *bridge);
> +       void (*mode_set)(struct drm_bridge *bridge,
> +                        struct drm_display_mode *mode,
> +                        struct drm_display_mode *adjusted_mode);
> +       void (*pre_enable)(struct drm_bridge *bridge);
> +       void (*enable)(struct drm_bridge *bridge);
> +       void (*destroy)(struct drm_bridge *bridge);
> +};
> +
> +/**
> + * drm_bridge - central DRM bridge control structure
> + * @dev: DRM device this bridge belongs to
> + * @head: list management
> + * @base: base mode object
> + * @funcs: control functions
> + * @driver_private: pointer to the bridge driver's internal context
> + */
> +struct drm_bridge {
> +       struct drm_device *dev;
> +       struct list_head head;
> +
> +       struct drm_mode_object base;
> +
> +       const struct drm_bridge_funcs *funcs;
> +       void *driver_private;
> +};
> +
> +/**
>   * drm_mode_set - new values for a CRTC config change
>   * @head: list management
>   * @fb: framebuffer to use for new config
> @@ -742,6 +788,7 @@ struct drm_mode_group {
>         uint32_t num_crtcs;
>         uint32_t num_encoders;
>         uint32_t num_connectors;
> +       uint32_t num_bridges;
>
>         /* list of object IDs for this group */
>         uint32_t *id_list;
> @@ -756,6 +803,8 @@ struct drm_mode_group {
>   * @fb_list: list of framebuffers available
>   * @num_connector: number of connectors on this device
>   * @connector_list: list of connector objects
> + * @num_bridge: number of bridges on this device
> + * @bridge_list: list of bridge objects
>   * @num_encoder: number of encoders on this device
>   * @encoder_list: list of encoder objects
>   * @num_crtc: number of CRTCs on this device
> @@ -793,6 +842,8 @@ struct drm_mode_config {
>
>         int num_connector;
>         struct list_head connector_list;
> +       int num_bridge;
> +       struct list_head bridge_list;
>         int num_encoder;
>         struct list_head encoder_list;
>         int num_plane;
> @@ -878,6 +929,10 @@ extern void drm_connector_cleanup(struct drm_connector *connector);
>  /* helper to unplug all connectors from sysfs for device */
>  extern void drm_connector_unplug_all(struct drm_device *dev);
>
> +extern int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
> +                          const struct drm_bridge_funcs *funcs);
> +extern void drm_bridge_cleanup(struct drm_bridge *bridge);
> +
>  extern int drm_encoder_init(struct drm_device *dev,
>                             struct drm_encoder *encoder,
>                             const struct drm_encoder_funcs *funcs,
> --
> 1.8.3
>