[RFC v4 11/25] drm/connector: Add connector array functions

[Noralf Trønnes]

Add functions to deal with the registred connectors as an array:
- drm_connector_get_all()
- drm_connector_put_all()

And to get the enabled status of those connectors:
drm_connector_get_enabled_status()

This is prep work to remove struct drm_fb_helper_connector.

Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
---
 drivers/gpu/drm/drm_connector.c | 105 ++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_connector.h     |   5 ++
 2 files changed, 110 insertions(+)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index b9eb143d70fc..25c333c05a4e 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1854,3 +1854,108 @@ drm_connector_pick_cmdline_mode(struct drm_connector *connector)
 	return mode;
 }
 EXPORT_SYMBOL(drm_connector_pick_cmdline_mode);
+
+/**
+ * drm_connector_get_all - Get all connectors into an array
+ * @dev: DRM device
+ * @connectors: Returned connector array
+ *
+ * This function iterates through all registered connectors and adds them to an
+ * array allocated by this function. A ref is taken on the connectors.
+ *
+ * Use drm_connector_put_all() to drop refs and free the array.
+ *
+ * Returns:
+ * Number of connectors or -ENOMEM on failure.
+ */
+int drm_connector_get_all(struct drm_device *dev, struct drm_connector ***connectors)
+{
+	struct drm_connector *connector, **temp, **conns = NULL;
+	struct drm_connector_list_iter conn_iter;
+	int connector_count = 0;
+
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
+		temp = krealloc(conns, (connector_count + 1) * sizeof(*conns), GFP_KERNEL);
+		if (!temp)
+			goto err_put_free;
+
+		conns = temp;
+		conns[connector_count++] = connector;
+		drm_connector_get(connector);
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	*connectors = conns;
+
+	return connector_count;
+
+err_put_free:
+	drm_connector_list_iter_end(&conn_iter);
+	drm_connector_put_all(conns, connector_count);
+
+	return -ENOMEM;
+}
+EXPORT_SYMBOL(drm_connector_get_all);
+
+/**
+ * drm_connector_put_all - Put and free connector array
+ * @connectors: Array of connectors
+ * @connector_count: Number of connectors in the array (can be negative or zero)
+ *
+ * This function drops the ref on the connectors an frees the array.
+ */
+void drm_connector_put_all(struct drm_connector **connectors, int connector_count)
+{
+	int i;
+
+	if (connector_count < 1)
+		return;
+
+	for (i = 0; i < connector_count; i++)
+		drm_connector_put(connectors[i]);
+	kfree(connectors);
+}
+EXPORT_SYMBOL(drm_connector_put_all);
+
+/**
+ * drm_connector_get_enabled_status - Get enabled status on connectors
+ * @connectors: Array of connectors
+ * @connector_count: Number of connectors in the array
+ *
+ * This loops over the connector array and sets enabled if connector status is
+ * _connected_. If no connectors are connected, a new pass is done and
+ * connectors that are not _disconnected_ are set enabled.
+ *
+ * The caller is responsible for freeing the array using kfree().
+ *
+ * Returns:
+ * A boolean array of connector enabled statuses or NULL on allocation failure.
+ */
+bool *drm_connector_get_enabled_status(struct drm_connector **connectors,
+				       unsigned int connector_count)
+{
+	bool *enabled, any_enabled = false;
+	unsigned int i;
+
+	enabled = kcalloc(connector_count, sizeof(*enabled), GFP_KERNEL);
+	if (!enabled)
+		return NULL;
+
+	for (i = 0; i < connector_count; i++) {
+		if (connectors[i]->status == connector_status_connected) {
+			enabled[i] = true;
+			any_enabled = true;
+		}
+	}
+
+	if (any_enabled)
+		return enabled;
+
+	for (i = 0; i < connector_count; i++)
+		if (connectors[i]->status != connector_status_disconnected)
+			enabled[i] = true;
+
+	return enabled;
+}
+EXPORT_SYMBOL(drm_connector_get_enabled_status);
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 9cb4ca42373c..c3556a5f40c9 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1169,4 +1169,9 @@ drm_connector_has_preferred_mode(struct drm_connector *connector,
 struct drm_display_mode *
 drm_connector_pick_cmdline_mode(struct drm_connector *connector);
 
+int drm_connector_get_all(struct drm_device *dev, struct drm_connector ***connectors);
+void drm_connector_put_all(struct drm_connector **connectors, int connector_count);
+bool *drm_connector_get_enabled_status(struct drm_connector **connectors,
+				       unsigned int connector_count);
+
 #endif
-- 
2.15.1