pm: EDP: positive E-state handing

This patch adds the basic positive E-state handling functionality.
Higher state transitions will fail if there is not enough current
remaining.

Bug ID: 917926

Change-Id: I1555a4d5b4df35883baa1cf9260ff66254a49b95
Signed-off-by: Sivaram Nair <sivaramn@nvidia.com>
Reviewed-on: http://git-master/r/115707
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com>
Tested-by: Varun Colbert <vcolbert@nvidia.com>

2 files changed, 66 insertions, 3 deletions

diff --git a/drivers/edp/edp.c b/drivers/edp/edp.c
index fcb94288d3b7..63a7df1b3f10 100644
--- a/drivers/edp/edp.c
+++ b/drivers/edp/edp.c
@@ -51,6 +51,7 @@ int edp_register_manager(struct edp_manager *mgr)
 	if (!find_manager(mgr->name)) {
 		list_add_tail(&mgr->link, &edp_managers);
 		mgr->registered = true;
+		mgr->remaining = mgr->imax;
 		INIT_LIST_HEAD(&mgr->clients);
 		r = 0;
 	}
@@ -156,6 +157,8 @@ static int register_client(struct edp_manager *mgr, struct edp_client *client)
 
 	list_add_tail(&client->link, &mgr->clients);
 	client->manager = mgr;
+	client->req = NULL;
+	client->cur = NULL;
 
 	return 0;
 }
@@ -172,6 +175,26 @@ int edp_register_client(struct edp_manager *mgr, struct edp_client *client)
 }
 EXPORT_SYMBOL(edp_register_client);
 
+static int mod_request(struct edp_client *client, const unsigned int *req)
+{
+	unsigned int old = client->cur ? *client->cur : 0;
+	unsigned int new = req ? *req : 0;
+	unsigned int need;
+
+	if (new < old) {
+		client->cur = req;
+		client->manager->remaining += old - new;
+	} else {
+		need = new - old;
+		if (need > client->manager->remaining)
+			return -ENODEV;
+		client->manager->remaining -= need;
+		client->cur = req;
+	}
+
+	return 0;
+}
+
 static int unregister_client(struct edp_client *client)
 {
 	if (!client)
@@ -180,9 +203,7 @@ static int unregister_client(struct edp_client *client)
 	if (!client->manager)
 		return -ENODEV;
 
-	if (!client->manager->registered)
-		return -ENODEV;
-
+	mod_request(client, NULL);
 	list_del(&client->link);
 	client->manager = NULL;
 
@@ -200,3 +221,37 @@ int edp_unregister_client(struct edp_client *client)
 	return r;
 }
 EXPORT_SYMBOL(edp_unregister_client);
+
+static int update_client_request(struct edp_client *client, unsigned int req,
+		int *approved)
+{
+	int r;
+
+	if (!client)
+		return -EINVAL;
+
+	if (!client->manager)
+		return -ENODEV;
+
+	if (req >= client->num_states)
+		return -EINVAL;
+
+	r = mod_request(client, client->states + req);
+	if (!r && approved)
+		*approved = client->cur - client->states;
+
+	return r;
+}
+
+int edp_update_client_request(struct edp_client *client, unsigned int req,
+		unsigned int *approved)
+{
+	int r;
+
+	mutex_lock(&edp_lock);
+	r = update_client_request(client, req, approved);
+	mutex_unlock(&edp_lock);
+
+	return r;
+}
+EXPORT_SYMBOL(edp_update_client_request);
diff --git a/include/linux/edp.h b/include/linux/edp.h
index 6d31123f4d6e..743d39a6b8e7 100644
--- a/include/linux/edp.h
+++ b/include/linux/edp.h
@@ -32,6 +32,7 @@ struct edp_manager {
 	struct list_head link;
 	struct list_head clients;
 	bool registered;
+	unsigned int remaining;
 };
 
 /*
@@ -50,6 +51,8 @@ struct edp_client {
 	/* internal */
 	struct list_head link;
 	struct edp_manager *manager;
+	const unsigned int *req;
+	const unsigned int *cur;
 };
 
 #ifdef CONFIG_EDP_FRAMEWORK
@@ -60,6 +63,8 @@ extern struct edp_manager *edp_get_manager(const char *name);
 extern int edp_register_client(struct edp_manager *mgr,
 		struct edp_client *client);
 extern int edp_unregister_client(struct edp_client *client);
+extern int edp_update_client_request(struct edp_client *client,
+		unsigned int req, unsigned int *approved);
 #else
 static inline int edp_register_manager(struct edp_manager *mgr)
 { return -ENODEV; }
@@ -72,6 +77,9 @@ static inline int edp_register_client(struct edp_manager *mgr,
 { return -ENODEV; }
 static inline int edp_unregister_client(struct edp_client *client)
 { return -ENODEV; }
+static inline int edp_update_client_request(struct edp_client *client,
+		unsigned int req, unsigned int *approved)
+{ return -ENODEV; }
 #endif
 
 #endif