drm/amd/display: Wait for ACK for INBOX0 HW Lock

[Why]
In DC we want to wait for the INBOX0 HW Lock command to ACK before
continuing. This is to ensure that the lock has been successfully
acquired before programming HW in DC.

[How]
Add interfaces to send messages on INBOX0, poll for their completation
and clear the ack.

Reviewed-by: Nicholas Kazlauskas <[email protected]>
Acked-by: Anson Jacob <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Alvin Lee <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

1 files changed, 35 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
index 4a2cb0cdb0ba..56a03328e8e6 100644
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
@@ -842,3 +842,38 @@ bool dmub_srv_should_detect(struct dmub_srv *dmub)
 
 	return dmub->hw_funcs.should_detect(dmub);
 }
+
+enum dmub_status dmub_srv_clear_inbox0_ack(struct dmub_srv *dmub)
+{
+	if (!dmub->hw_init || dmub->hw_funcs.clear_inbox0_ack_register)
+		return DMUB_STATUS_INVALID;
+
+	dmub->hw_funcs.clear_inbox0_ack_register(dmub);
+	return DMUB_STATUS_OK;
+}
+
+enum dmub_status dmub_srv_wait_for_inbox0_ack(struct dmub_srv *dmub, uint32_t timeout_us)
+{
+	uint32_t i = 0;
+	uint32_t ack = 0;
+
+	if (!dmub->hw_init || !dmub->hw_funcs.read_inbox0_ack_register)
+		return DMUB_STATUS_INVALID;
+
+	for (i = 0; i <= timeout_us; i++) {
+		ack = dmub->hw_funcs.read_inbox0_ack_register(dmub);
+		if (ack)
+			return DMUB_STATUS_OK;
+	}
+	return DMUB_STATUS_TIMEOUT;
+}
+
+enum dmub_status dmub_srv_send_inbox0_cmd(struct dmub_srv *dmub,
+		union dmub_inbox0_data_register data)
+{
+	if (!dmub->hw_init || dmub->hw_funcs.send_inbox0_cmd)
+		return DMUB_STATUS_INVALID;
+
+	dmub->hw_funcs.send_inbox0_cmd(dmub, data);
+	return DMUB_STATUS_OK;
+}