[PATCH v16 09/40] gpu: host1x: Add host1x_channel_stop()

[Dmitry Osipenko]

Add host1x_channel_stop() which waits till channel becomes idle and then
stops the channel hardware. This is needed for supporting suspend/resume
by host1x drivers since the hardware state is lost after power-gating,
thus the channel needs to be stopped before client enters into suspend.

Tested-by: Peter Geis <pgwipeout at gmail.com> # Ouya T30
Tested-by: Paul Fertser <fercerpav at gmail.com> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwizart at gmail.com> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmerhar at protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx at gmail.com>
---
 drivers/gpu/host1x/channel.c | 8 ++++++++
 include/linux/host1x.h       | 1 +
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/host1x/channel.c b/drivers/gpu/host1x/channel.c
index 4cd212bb570d..2a9a3a8d5931 100644
--- a/drivers/gpu/host1x/channel.c
+++ b/drivers/gpu/host1x/channel.c
@@ -75,6 +75,14 @@ struct host1x_channel *host1x_channel_get_index(struct host1x *host,
 	return ch;
 }
 
+void host1x_channel_stop(struct host1x_channel *channel)
+{
+	struct host1x *host = dev_get_drvdata(channel->dev->parent);
+
+	host1x_hw_cdma_stop(host, &channel->cdma);
+}
+EXPORT_SYMBOL(host1x_channel_stop);
+
 static void release_channel(struct kref *kref)
 {
 	struct host1x_channel *channel =
diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index 2ca53d7ed7ca..e8dc5bc41f79 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -226,6 +226,7 @@ struct host1x_job;
 
 struct host1x_channel *host1x_channel_request(struct host1x_client *client);
 struct host1x_channel *host1x_channel_get(struct host1x_channel *channel);
+void host1x_channel_stop(struct host1x_channel *channel);
 void host1x_channel_put(struct host1x_channel *channel);
 int host1x_job_submit(struct host1x_job *job);
 
-- 
2.33.1