[PATCH v2 1/7] drm/bridge: Refactor out the panel wrapper from the lvds-encoder bridge.

From: Eric Anholt
Date: Thu May 11 2017 - 14:31:43 EST


Many DRM drivers have common code to make a stub connector
implementation that wraps a drm_panel. By wrapping the panel in a DRM
bridge, all of the connector code (including calls during encoder
enable/disable) goes away.

v2: Fix build with CONFIG_DRM=m, drop "dev" argument that should just
be the panel's dev, move kerneldoc up a level and document
_remove().

Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
Documentation/gpu/drm-kms-helpers.rst | 6 ++
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/bridge/Kconfig | 11 +-
drivers/gpu/drm/bridge/lvds-encoder.c | 157 ++++-----------------------
drivers/gpu/drm/bridge/panel.c | 197 ++++++++++++++++++++++++++++++++++
include/drm/drm_bridge.h | 7 ++
6 files changed, 238 insertions(+), 141 deletions(-)
create mode 100644 drivers/gpu/drm/bridge/panel.c

diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index c075aadd7078..7c5e2549a58a 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -143,6 +143,12 @@ Bridge Helper Reference
.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
:export:

+Panel-Bridge Helper Reference
+-----------------------------
+
+.. kernel-doc:: drivers/gpu/drm/bridge/panel.c
+ :export:
+
.. _drm_panel_helper:

Panel Helper Reference
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index c156fecfb362..4cc9c02cc3f2 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -24,6 +24,7 @@ drm-$(CONFIG_COMPAT) += drm_ioc32.o
drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
drm-$(CONFIG_PCI) += ati_pcigart.o
drm-$(CONFIG_DRM_PANEL) += drm_panel.o
+drm-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
drm-$(CONFIG_OF) += drm_of.o
drm-$(CONFIG_AGP) += drm_agpsupport.o
drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index f6968d3b4b41..c4daca38743c 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -4,6 +4,14 @@ config DRM_BRIDGE
help
Bridge registration and lookup framework.

+config DRM_PANEL_BRIDGE
+ def_bool y
+ depends on DRM_BRIDGE
+ select DRM_KMS_HELPER
+ select DRM_PANEL
+ help
+ DRM bridge wrapper of DRM panels
+
menu "Display Interface Bridges"
depends on DRM && DRM_BRIDGE

@@ -27,8 +35,7 @@ config DRM_DUMB_VGA_DAC
config DRM_LVDS_ENCODER
tristate "Transparent parallel to LVDS encoder support"
depends on OF
- select DRM_KMS_HELPER
- select DRM_PANEL
+ select DRM_PANEL_BRIDGE
help
Support for transparent parallel to LVDS encoders that don't require
any configuration.
diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c
index f1f67a279426..0903ba574f61 100644
--- a/drivers/gpu/drm/bridge/lvds-encoder.c
+++ b/drivers/gpu/drm/bridge/lvds-encoder.c
@@ -8,144 +8,18 @@
*/

#include <drm/drmP.h>
-#include <drm/drm_atomic_helper.h>
-#include <drm/drm_connector.h>
-#include <drm/drm_crtc_helper.h>
-#include <drm/drm_encoder.h>
-#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_bridge.h>
#include <drm/drm_panel.h>

#include <linux/of_graph.h>

-struct lvds_encoder {
- struct device *dev;
-
- struct drm_bridge bridge;
- struct drm_connector connector;
- struct drm_panel *panel;
-};
-
-static inline struct lvds_encoder *
-drm_bridge_to_lvds_encoder(struct drm_bridge *bridge)
-{
- return container_of(bridge, struct lvds_encoder, bridge);
-}
-
-static inline struct lvds_encoder *
-drm_connector_to_lvds_encoder(struct drm_connector *connector)
-{
- return container_of(connector, struct lvds_encoder, connector);
-}
-
-static int lvds_connector_get_modes(struct drm_connector *connector)
-{
- struct lvds_encoder *lvds = drm_connector_to_lvds_encoder(connector);
-
- return drm_panel_get_modes(lvds->panel);
-}
-
-static const struct drm_connector_helper_funcs lvds_connector_helper_funcs = {
- .get_modes = lvds_connector_get_modes,
-};
-
-static const struct drm_connector_funcs lvds_connector_funcs = {
- .dpms = drm_atomic_helper_connector_dpms,
- .reset = drm_atomic_helper_connector_reset,
- .fill_modes = drm_helper_probe_single_connector_modes,
- .destroy = drm_connector_cleanup,
- .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
- .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
-};
-
-static int lvds_encoder_attach(struct drm_bridge *bridge)
-{
- struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
- struct drm_connector *connector = &lvds->connector;
- int ret;
-
- if (!bridge->encoder) {
- DRM_ERROR("Missing encoder\n");
- return -ENODEV;
- }
-
- drm_connector_helper_add(connector, &lvds_connector_helper_funcs);
-
- ret = drm_connector_init(bridge->dev, connector, &lvds_connector_funcs,
- DRM_MODE_CONNECTOR_LVDS);
- if (ret) {
- DRM_ERROR("Failed to initialize connector\n");
- return ret;
- }
-
- drm_mode_connector_attach_encoder(&lvds->connector, bridge->encoder);
-
- ret = drm_panel_attach(lvds->panel, &lvds->connector);
- if (ret < 0)
- return ret;
-
- return 0;
-}
-
-static void lvds_encoder_detach(struct drm_bridge *bridge)
-{
- struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
-
- drm_panel_detach(lvds->panel);
-}
-
-static void lvds_encoder_pre_enable(struct drm_bridge *bridge)
-{
- struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
-
- drm_panel_prepare(lvds->panel);
-}
-
-static void lvds_encoder_enable(struct drm_bridge *bridge)
-{
- struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
-
- drm_panel_enable(lvds->panel);
-}
-
-static void lvds_encoder_disable(struct drm_bridge *bridge)
-{
- struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
-
- drm_panel_disable(lvds->panel);
-}
-
-static void lvds_encoder_post_disable(struct drm_bridge *bridge)
-{
- struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
-
- drm_panel_unprepare(lvds->panel);
-}
-
-static const struct drm_bridge_funcs lvds_encoder_bridge_funcs = {
- .attach = lvds_encoder_attach,
- .detach = lvds_encoder_detach,
- .pre_enable = lvds_encoder_pre_enable,
- .enable = lvds_encoder_enable,
- .disable = lvds_encoder_disable,
- .post_disable = lvds_encoder_post_disable,
-};
-
static int lvds_encoder_probe(struct platform_device *pdev)
{
- struct lvds_encoder *lvds;
struct device_node *port;
struct device_node *endpoint;
- struct device_node *panel;
-
- lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
- if (!lvds)
- return -ENOMEM;
-
- lvds->dev = &pdev->dev;
- platform_set_drvdata(pdev, lvds);
-
- lvds->bridge.funcs = &lvds_encoder_bridge_funcs;
- lvds->bridge.of_node = pdev->dev.of_node;
+ struct device_node *panel_node;
+ struct drm_panel *panel;
+ struct drm_bridge *bridge;

/* Locate the panel DT node. */
port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
@@ -161,29 +35,34 @@ static int lvds_encoder_probe(struct platform_device *pdev)
return -ENXIO;
}

- panel = of_graph_get_remote_port_parent(endpoint);
+ panel_node = of_graph_get_remote_port_parent(endpoint);
of_node_put(endpoint);
- if (!panel) {
+ if (!panel_node) {
dev_dbg(&pdev->dev, "no remote endpoint for port 1\n");
return -ENXIO;
}

- lvds->panel = of_drm_find_panel(panel);
- of_node_put(panel);
- if (!lvds->panel) {
+ panel = of_drm_find_panel(panel_node);
+ of_node_put(panel_node);
+ if (!panel) {
dev_dbg(&pdev->dev, "panel not found, deferring probe\n");
return -EPROBE_DEFER;
}

- /* Register the bridge. */
- return drm_bridge_add(&lvds->bridge);
+ bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_LVDS);
+ if (IS_ERR(bridge))
+ return PTR_ERR(bridge);
+
+ platform_set_drvdata(pdev, bridge);
+
+ return 0;
}

static int lvds_encoder_remove(struct platform_device *pdev)
{
- struct lvds_encoder *encoder = platform_get_drvdata(pdev);
+ struct drm_bridge *bridge = platform_get_drvdata(pdev);

- drm_bridge_remove(&encoder->bridge);
+ drm_bridge_remove(bridge);

return 0;
}
diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
new file mode 100644
index 000000000000..fd1a78cb1205
--- /dev/null
+++ b/drivers/gpu/drm/bridge/panel.c
@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
+ * Copyright (C) 2017 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_panel.h>
+
+struct panel_bridge {
+ struct drm_bridge bridge;
+ struct drm_connector connector;
+ struct drm_panel *panel;
+ u32 connector_type;
+};
+
+static inline struct panel_bridge *
+drm_bridge_to_panel_bridge(struct drm_bridge *bridge)
+{
+ return container_of(bridge, struct panel_bridge, bridge);
+}
+
+static inline struct panel_bridge *
+drm_connector_to_panel_bridge(struct drm_connector *connector)
+{
+ return container_of(connector, struct panel_bridge, connector);
+}
+
+static int panel_bridge_connector_get_modes(struct drm_connector *connector)
+{
+ struct panel_bridge *panel_bridge =
+ drm_connector_to_panel_bridge(connector);
+
+ return drm_panel_get_modes(panel_bridge->panel);
+}
+
+static const struct drm_connector_helper_funcs panel_bridge_connector_helper_funcs = {
+ .get_modes = panel_bridge_connector_get_modes,
+};
+
+static const struct drm_connector_funcs panel_bridge_connector_funcs = {
+ .dpms = drm_atomic_helper_connector_dpms,
+ .reset = drm_atomic_helper_connector_reset,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = drm_connector_cleanup,
+ .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static int panel_bridge_attach(struct drm_bridge *bridge)
+{
+ struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+ struct drm_connector *connector = &panel_bridge->connector;
+ int ret;
+
+ if (!bridge->encoder) {
+ DRM_ERROR("Missing encoder\n");
+ return -ENODEV;
+ }
+
+ drm_connector_helper_add(connector,
+ &panel_bridge_connector_helper_funcs);
+
+ ret = drm_connector_init(bridge->dev, connector,
+ &panel_bridge_connector_funcs,
+ panel_bridge->connector_type);
+ if (ret) {
+ DRM_ERROR("Failed to initialize connector\n");
+ return ret;
+ }
+
+ drm_mode_connector_attach_encoder(&panel_bridge->connector,
+ bridge->encoder);
+
+ ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static void panel_bridge_detach(struct drm_bridge *bridge)
+{
+ struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+
+ drm_panel_detach(panel_bridge->panel);
+}
+
+static void panel_bridge_pre_enable(struct drm_bridge *bridge)
+{
+ struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+
+ drm_panel_prepare(panel_bridge->panel);
+}
+
+static void panel_bridge_enable(struct drm_bridge *bridge)
+{
+ struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+
+ drm_panel_enable(panel_bridge->panel);
+}
+
+static void panel_bridge_disable(struct drm_bridge *bridge)
+{
+ struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+
+ drm_panel_disable(panel_bridge->panel);
+}
+
+static void panel_bridge_post_disable(struct drm_bridge *bridge)
+{
+ struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+
+ drm_panel_unprepare(panel_bridge->panel);
+}
+
+static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
+ .attach = panel_bridge_attach,
+ .detach = panel_bridge_detach,
+ .pre_enable = panel_bridge_pre_enable,
+ .enable = panel_bridge_enable,
+ .disable = panel_bridge_disable,
+ .post_disable = panel_bridge_post_disable,
+};
+
+/**
+ * drm_panel_bridge_add - Creates a drm_bridge and drm_connector that
+ * just calls the appropriate functions from drm_panel.
+ *
+ * @panel: The drm_panel being wrapped. Must be non-NULL.
+ * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
+ * created.
+ *
+ * For drivers converting from directly using drm_panel: The expected
+ * usage pattern is that during either encoder module probe or DSI
+ * host attach, a drm_panel will be looked up through
+ * drm_of_find_panel_or_bridge(). drm_panel_bridge_add() is used to
+ * wrap that panel in the new bridge, and the result can then be
+ * passed to drm_bridge_attach(). The drm_panel_prepare() and related
+ * functions can be dropped from the encoder driver (they're now
+ * called by the KMS helpers before calling into the encoder), along
+ * with connector creation. When done with the bridge,
+ * drm_bridge_detach() should be called as normal, then
+ * drm_panel_bridge_remove() to free it.
+ */
+struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
+ u32 connector_type)
+{
+ struct panel_bridge *panel_bridge;
+ int ret;
+
+ if (!panel)
+ return ERR_PTR(EINVAL);
+
+ panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
+ GFP_KERNEL);
+ if (!panel_bridge)
+ return ERR_PTR(-ENOMEM);
+
+ panel_bridge->connector_type = connector_type;
+ panel_bridge->panel = panel;
+
+ panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
+ panel_bridge->bridge.of_node = panel->dev->of_node;
+
+ ret = drm_bridge_add(&panel_bridge->bridge);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return &panel_bridge->bridge;
+}
+EXPORT_SYMBOL(drm_panel_bridge_add);
+
+/**
+ * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
+ * created by drm_panel_bridge_add().
+ *
+ * @bridge: The drm_bridge being freed.
+ */
+void drm_panel_bridge_remove(struct drm_bridge *bridge)
+{
+ struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+
+ drm_bridge_remove(bridge);
+ devm_kfree(panel_bridge->panel->dev, bridge);
+}
+EXPORT_SYMBOL(drm_panel_bridge_remove);
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index fdd82fcbf168..bad2178ea3e0 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -29,6 +29,7 @@
#include <drm/drm_modes.h>

struct drm_bridge;
+struct drm_panel;

/**
* struct drm_bridge_funcs - drm_bridge control functions
@@ -221,4 +222,10 @@ void drm_bridge_mode_set(struct drm_bridge *bridge,
void drm_bridge_pre_enable(struct drm_bridge *bridge);
void drm_bridge_enable(struct drm_bridge *bridge);

+#ifdef CONFIG_DRM_PANEL
+struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
+ u32 connector_type);
+void drm_panel_bridge_remove(struct drm_bridge *bridge);
+#endif
+
#endif
--
2.11.0