[PATCH 3/5] DRM: Add drm encoder/connector helper

[s.hauer@pengutronix.de (Sascha Hauer)]

At least in the embedded world encoders and connectors are not
at all visible in software. Often enough there is a 1:1
relationship between encoders and connectors. Add helpers to
handle this case and to ease driver implementation for SoCs.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/gpu/drm/Kconfig     |    7 +
 drivers/gpu/drm/Makefile    |    1 +
 drivers/gpu/drm/drm_encon.c |  302 +++++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_encon.h     |   46 +++++++
 4 files changed, 356 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_encon.c
 create mode 100644 include/drm/drm_encon.h

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 969dc38..bcd9a27 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -28,6 +28,13 @@ config DRM_KMS_HELPER
 	help
 	  FB and CRTC helpers for KMS drivers.
 
+config DRM_KMS_ENCON
+	tristate
+	depends on DRM
+	help
+	  helper for KMS drivers which use connectors and encoders with
+	  a 1:1 relationship
+
 config DRM_TTM
 	tristate
 	depends on DRM
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 97c35eb..19a1aec 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -19,6 +19,7 @@ drm-$(CONFIG_COMPAT) += drm_ioc32.o
 drm_kms_helper-y := drm_fb_helper.o drm_crtc_helper.o drm_dp_i2c_helper.o
 
 obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
+obj-$(CONFIG_DRM_KMS_ENCON) += drm_encon.o
 
 CFLAGS_drm_trace_points.o := -I$(src)
 
diff --git a/drivers/gpu/drm/drm_encon.c b/drivers/gpu/drm/drm_encon.c
new file mode 100644
index 0000000..42d46c8
--- /dev/null
+++ b/drivers/gpu/drm/drm_encon.c
@@ -0,0 +1,302 @@
+/*
+ * Implementation of a 1:1 relationship for drm encoders and connectors
+ *
+ * Copyright (C) 2011 Sascha Hauer, Pengutronix
+ *
+ * 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.
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#include <drm/drmP.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_encoder_slave.h>
+#include <drm/drm_encon.h>
+
+#define con_to_encon(x) container_of(x, struct drm_encoder_connector, connector)
+#define enc_to_encon(x) container_of(x, struct drm_encoder_connector, encoder)
+
+static enum drm_connector_status connector_detect(struct drm_connector *connector,
+		bool force)
+{
+	struct drm_encoder_connector *encon = con_to_encon(connector);
+
+	if (encon->funcs->detect)
+		return encon->funcs->detect(encon);
+
+	return connector_status_connected;
+}
+
+static int connector_set_property(struct drm_connector *connector,
+		struct drm_property *property, uint64_t val)
+{
+	struct drm_encoder_connector *encon = con_to_encon(connector);
+
+	if (encon->funcs->set_property)
+		return encon->funcs->set_property(encon, property, val);
+
+	return -EINVAL;
+}
+
+static void connector_destroy(struct drm_connector *connector)
+{
+	/* not here */
+}
+
+static int connector_get_modes(struct drm_connector *connector)
+{
+	struct drm_encoder_connector *encon = con_to_encon(connector);
+
+	if (encon->funcs->get_modes)
+		return encon->funcs->get_modes(encon);
+
+	return 0;
+}
+
+static int connector_mode_valid(struct drm_connector *connector,
+			  struct drm_display_mode *mode)
+{
+	struct drm_encoder_connector *encon = con_to_encon(connector);
+
+	if (encon->funcs && encon->funcs->mode_valid)
+		return encon->funcs->mode_valid(encon, mode);
+
+	return 0;
+}
+
+static struct drm_encoder *connector_best_encoder(struct drm_connector *connector)
+{
+	struct drm_encoder_connector *encon = con_to_encon(connector);
+
+	return &encon->encoder;
+}
+
+static void encoder_reset(struct drm_encoder *encoder)
+{
+	struct drm_encoder_connector *encon = enc_to_encon(encoder);
+
+	if (encon->funcs && encon->funcs->reset)
+		encon->funcs->reset(encon);
+}
+
+static void encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+	struct drm_encoder_connector *encon = enc_to_encon(encoder);
+
+	if (encon->funcs->dpms)
+		encon->funcs->dpms(encon, mode);
+}
+
+static bool encoder_mode_fixup(struct drm_encoder *encoder,
+			   struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode)
+{
+	struct drm_encoder_connector *encon = enc_to_encon(encoder);
+
+	if (encon->funcs->mode_fixup)
+		return encon->funcs->mode_fixup(encon, mode, adjusted_mode);
+
+	return true;
+}
+
+static void encoder_prepare(struct drm_encoder *encoder)
+{
+	struct drm_encoder_connector *encon = enc_to_encon(encoder);
+
+	if (encon->funcs->prepare)
+		encon->funcs->prepare(encon);
+}
+
+static void encoder_commit(struct drm_encoder *encoder)
+{
+	struct drm_encoder_connector *encon = enc_to_encon(encoder);
+
+	if (encon->funcs->commit)
+		encon->funcs->commit(encon);
+}
+
+static void encoder_mode_set(struct drm_encoder *encoder,
+			 struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode)
+{
+	struct drm_encoder_connector *encon = enc_to_encon(encoder);
+
+	if (encon->funcs->mode_set)
+		encon->funcs->mode_set(encon, mode, adjusted_mode);
+}
+
+static void encoder_disable(struct drm_encoder *encoder)
+{
+}
+
+static void encoder_destroy(struct drm_encoder *encoder)
+{
+	/* not here */
+}
+
+struct drm_connector_funcs connector_funcs = {
+	.dpms = drm_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	/* .save unused in drm, only used in nouveau */
+	/* .restore unused in drm, only used in nouveau */
+	.detect = connector_detect,
+	/* .reset called by encoder */
+	.set_property = connector_set_property,
+	.destroy = connector_destroy,
+};
+
+struct drm_connector_helper_funcs connector_helper_funcs = {
+	.get_modes = connector_get_modes,
+	.mode_valid = connector_mode_valid,
+	.best_encoder = connector_best_encoder,
+};
+
+static struct drm_encoder_funcs encoder_funcs = {
+	.reset = encoder_reset,
+	.destroy = encoder_destroy,
+};
+
+static struct drm_encoder_helper_funcs encoder_helper_funcs = {
+	.dpms = encoder_dpms,
+	/* .save unused in drm, only used in nouveau */
+	/* .restore unused in drm, only used in nouveau */
+	/* .detect unused in drm, only used in nouveau, radeon */
+	.mode_fixup = encoder_mode_fixup,
+	.prepare = encoder_prepare,
+	.commit = encoder_commit,
+	.mode_set = encoder_mode_set,
+	.disable = encoder_disable,
+};
+
+int drm_encoder_connector_init(struct drm_device *drm,
+		struct drm_encoder_connector *c)
+{
+	struct drm_connector *connector = &c->connector;
+	struct drm_encoder *encoder = &c->encoder;
+
+	drm_connector_helper_add(connector, &connector_helper_funcs);
+	drm_connector_init(drm, &c->connector,
+			   &connector_funcs, DRM_MODE_CONNECTOR_VGA);
+
+	drm_encoder_init(drm, encoder, &encoder_funcs, DRM_MODE_ENCODER_TMDS);
+	drm_encoder_helper_add(encoder, &encoder_helper_funcs);
+
+	drm_mode_connector_attach_encoder(connector, encoder);
+	drm_sysfs_connector_add(connector);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_encoder_connector_init);
+
+void drm_encoder_connector_cleanup(struct drm_device *drm,
+		struct drm_encoder_connector *c)
+{
+	struct drm_connector *connector = &c->connector;
+	struct drm_encoder *encoder = &c->encoder;
+
+	drm_sysfs_connector_remove(connector);
+	drm_mode_connector_detach_encoder(connector, encoder);
+	drm_encoder_cleanup(encoder);
+	drm_connector_cleanup(connector);
+	c->inuse = 0;
+}
+EXPORT_SYMBOL_GPL(drm_encoder_connector_cleanup);
+
+static LIST_HEAD(encon_list);
+static DEFINE_MUTEX(encon_list_mutex);
+
+int drm_encon_register(const char *drm_name, int id,
+		struct drm_encoder_connector *encon)
+{
+	encon->drm_name = kstrdup(drm_name, GFP_KERNEL);
+	encon->id = id;
+
+	mutex_lock(&encon_list_mutex);
+	list_add_tail(&encon->list, &encon_list);
+	mutex_unlock(&encon_list_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_encon_register);
+
+int drm_encon_unregister(struct drm_encoder_connector *encon)
+{
+	if (encon->inuse)
+		return -EBUSY;
+
+	kfree(encon->drm_name);
+
+	mutex_lock(&encon_list_mutex);
+	list_del(&encon->list);
+	mutex_unlock(&encon_list_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_encon_unregister);
+
+struct drm_encoder_connector *drm_encon_get(struct drm_device *drm, int id)
+{
+	const char *drm_name = dev_name(drm->dev);
+	struct drm_encoder_connector *encon;
+
+	mutex_lock(&encon_list_mutex);
+	list_for_each_entry(encon, &encon_list, list) {
+		if (!strcmp(drm_name, encon->drm_name) && encon->id == id) {
+			if (encon->inuse)
+				goto out;
+			encon->inuse = 1;
+			mutex_unlock(&encon_list_mutex);
+			return encon;
+		}
+	}
+out:
+	mutex_unlock(&encon_list_mutex);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(drm_encon_get);
+
+static struct drm_encoder_connector_funcs dummy_funcs;
+
+/* TODO: allow to pass an array of fixed modes */
+struct drm_encoder_connector *drm_encon_add_dummy(const char *drm_name, int id)
+{
+	struct drm_encoder_connector *encon;
+	int ret;
+
+	encon = kzalloc(sizeof(*encon), GFP_KERNEL);
+	if (!encon)
+		return NULL;
+
+	encon->funcs = &dummy_funcs;
+	ret = drm_encon_register(drm_name, id, encon);
+	if (ret) {
+		kfree(encon);
+		return NULL;
+	}
+
+	return encon;
+}
+EXPORT_SYMBOL_GPL(drm_encon_add_dummy);
+
+int drm_encon_remove_dummy(struct drm_encoder_connector *encon)
+{
+	int ret;
+
+	ret = drm_encon_unregister(encon);
+	if (ret)
+		return ret;
+	kfree(encon);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_encon_remove_dummy);
diff --git a/include/drm/drm_encon.h b/include/drm/drm_encon.h
new file mode 100644
index 0000000..f1d290b
--- /dev/null
+++ b/include/drm/drm_encon.h
@@ -0,0 +1,46 @@
+#ifndef __DRM_ENCON_H
+#define __DRM_ENCON_H
+
+struct drm_encoder_connector;
+
+struct drm_encoder_connector_funcs {
+	int (*get_modes)(struct drm_encoder_connector *encon);
+	int (*mode_valid)(struct drm_encoder_connector *encon,
+			struct drm_display_mode *mode);
+	void (*mode_set)(struct drm_encoder_connector *encon,
+			 struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode);
+	void (*reset)(struct drm_encoder_connector *encon);
+	void (*dpms)(struct drm_encoder_connector *encon, int mode);
+	enum drm_connector_status (*detect)(struct drm_encoder_connector *encon);
+	void (*commit)(struct drm_encoder_connector *encon);
+	bool (*mode_fixup)(struct drm_encoder_connector *encon,
+			struct drm_display_mode *mode,
+			struct drm_display_mode *adjusted_mode);
+	void (*prepare)(struct drm_encoder_connector *encon);
+	int (*set_property)(struct drm_encoder_connector *encon,
+			struct drm_property *property, uint64_t val);
+};
+
+struct drm_encoder_connector {
+	struct drm_connector connector;
+	struct drm_encoder encoder;
+	struct drm_encoder_connector_funcs *funcs;
+	struct list_head list;
+	int id;
+	const char *drm_name;
+	int inuse;
+};
+
+int drm_encoder_connector_init(struct drm_device *drm,
+		struct drm_encoder_connector *c);
+void drm_encoder_connector_cleanup(struct drm_device *drm,
+		struct drm_encoder_connector *c);
+int drm_encon_register(const char *drm_name, int id,
+		struct drm_encoder_connector *encon);
+int drm_encon_unregister(struct drm_encoder_connector *encon);
+struct drm_encoder_connector *drm_encon_get(struct drm_device *drm, int id);
+struct drm_encoder_connector *drm_encon_add_dummy(const char *drm_name, int id);
+int drm_encon_remove_dummy(struct drm_encoder_connector *encon);
+
+#endif /* __DRM_ENCON_H */
-- 
1.7.5.3