[PATCH v2 08/10] gpu: host1x: Add early init and late exit callbacks

[Thierry Reding]

From: Thierry Reding <treding at nvidia.com>

These callbacks can be used by client drivers to run code during early
init and during late exit. Early init callbacks are run prior to the
regular init callbacks while late exit callbacks run after the regular
exit callbacks.

Signed-off-by: Thierry Reding <treding at nvidia.com>
---
 drivers/gpu/host1x/bus.c | 31 +++++++++++++++++++++++++++++++
 include/linux/host1x.h   |  2 ++
 2 files changed, 33 insertions(+)

diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
index 4c18874f7c4a..c9077cfbfef9 100644
--- a/drivers/gpu/host1x/bus.c
+++ b/drivers/gpu/host1x/bus.c
@@ -196,6 +196,17 @@ int host1x_device_init(struct host1x_device *device)
 
 	mutex_lock(&device->clients_lock);
 
+	list_for_each_entry(client, &device->clients, list) {
+		if (client->ops && client->ops->early_init) {
+			err = client->ops->early_init(client);
+			if (err < 0) {
+				dev_err(&device->dev, "failed to early initialize %s: %d\n",
+					dev_name(client->dev), err);
+				goto teardown_late;
+			}
+		}
+	}
+
 	list_for_each_entry(client, &device->clients, list) {
 		if (client->ops && client->ops->init) {
 			err = client->ops->init(client);
@@ -217,6 +228,14 @@ int host1x_device_init(struct host1x_device *device)
 		if (client->ops->exit)
 			client->ops->exit(client);
 
+	/* reset client to end of list for late teardown */
+	client = list_entry(&device->clients, struct host1x_client, list);
+
+teardown_late:
+	list_for_each_entry_continue_reverse(client, &device->clients, list)
+		if (client->ops->late_exit)
+			client->ops->late_exit(client);
+
 	mutex_unlock(&device->clients_lock);
 	return err;
 }
@@ -251,6 +270,18 @@ int host1x_device_exit(struct host1x_device *device)
 		}
 	}
 
+	list_for_each_entry_reverse(client, &device->clients, list) {
+		if (client->ops && client->ops->late_exit) {
+			err = client->ops->late_exit(client);
+			if (err < 0) {
+				dev_err(&device->dev, "failed to late cleanup %s: %d\n",
+					dev_name(client->dev), err);
+				mutex_unlock(&device->clients_lock);
+				return err;
+			}
+		}
+	}
+
 	mutex_unlock(&device->clients_lock);
 
 	return 0;
diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index 5890f91dd286..74970681ecdb 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -31,8 +31,10 @@ u64 host1x_get_dma_mask(struct host1x *host1x);
  * @resume: host1x client resume code
  */
 struct host1x_client_ops {
+	int (*early_init)(struct host1x_client *client);
 	int (*init)(struct host1x_client *client);
 	int (*exit)(struct host1x_client *client);
+	int (*late_exit)(struct host1x_client *client);
 	int (*suspend)(struct host1x_client *client);
 	int (*resume)(struct host1x_client *client);
 };
-- 
2.30.2