[PATCH v10 7/8] gpu: host1x: Add host1x_channel_stop()

Dmitry Osipenko
2021-08-31T13:57:38Z

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@gmail.com> # Ouya T30
Tested-by: Paul Fertser <fercerpav@gmail.com> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@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 7bccf589aba7..66473b5be0af 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -181,6 +181,7 @@ 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);

--
2.32.0