[Intel-gfx] [PATCH v5 11/22] drm/i915/slpc: Add slpc communication interfaces

[Sagar Arun Kamble]

From: Tom O'Rourke <Tom.O'Rourke at intel.com>

Communication with SLPC is via Host to GuC interrupt.
This patch defines the data structure to be passed as input
and received as output from SLPC. This patch also defines the
events to be sent as input and status values output by GuC
on processing SLPC events.

v1: fix whitespace (Sagar)

v2-v3: Rebase.

v4: Updated with GuC firmware v9.

v5: Added definition of input and output data structures for SLPC
events. Updated commit message.

Signed-off-by: Tom O'Rourke <Tom.O'Rourke at intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/intel_slpc.c | 30 +++++++++++++++++
 drivers/gpu/drm/i915/intel_slpc.h | 71 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_slpc.c b/drivers/gpu/drm/i915/intel_slpc.c
index 945d265..57d0d03 100644
--- a/drivers/gpu/drm/i915/intel_slpc.c
+++ b/drivers/gpu/drm/i915/intel_slpc.c
@@ -82,6 +82,36 @@ static void slpc_shared_data_init(struct drm_i915_private *dev_priv)
 	kunmap_atomic(data);
 }
 
+static void host2guc_slpc(struct drm_i915_private *dev_priv,
+			  struct slpc_event_input *input, u32 len)
+{
+	union slpc_event_output_header header;
+	u32 *data;
+	int ret = 0;
+
+	/*
+	 * We have only 15 scratch registers for communication.
+	 * the first we will use for the event ID in input and
+	 * output data. Event processing status will be present
+	 * in SOFT_SCRATCH(1) register.
+	 */
+	BUILD_BUG_ON(SLPC_EVENT_MAX_INPUT_ARGS > 14);
+	BUILD_BUG_ON(SLPC_EVENT_MAX_OUTPUT_ARGS < 1);
+	BUILD_BUG_ON(SLPC_EVENT_MAX_OUTPUT_ARGS > 14);
+
+	data = (u32 *) input;
+	data[0] = HOST2GUC_ACTION_SLPC_REQUEST;
+	ret = i915_guc_action(&dev_priv->guc, data, len);
+
+	if (!ret) {
+		header.value = I915_READ(SOFT_SCRATCH(1));
+		ret = header.status;
+	}
+
+	if (ret)
+		DRM_ERROR("event 0x%x status %d\n", (data[1] >> 8), ret);
+}
+
 void intel_slpc_init(struct drm_i915_private *dev_priv)
 {
 	struct intel_guc *guc = &dev_priv->guc;
diff --git a/drivers/gpu/drm/i915/intel_slpc.h b/drivers/gpu/drm/i915/intel_slpc.h
index 2d81443..4378265 100644
--- a/drivers/gpu/drm/i915/intel_slpc.h
+++ b/drivers/gpu/drm/i915/intel_slpc.h
@@ -123,6 +123,77 @@ struct intel_slpc {
 	struct i915_vma *vma;
 };
 
+#define SLPC_EVENT_MAX_INPUT_ARGS  7
+#define SLPC_EVENT_MAX_OUTPUT_ARGS 1
+
+union slpc_event_input_header {
+	u32 value;
+	struct {
+		u32 num_args:8;
+		u32 event_id:8;
+	};
+};
+
+struct slpc_event_input {
+	u32 h2g_action_id;
+	union slpc_event_input_header header;
+	u32 args[SLPC_EVENT_MAX_INPUT_ARGS];
+} __packed;
+
+union slpc_event_output_header {
+	u32 value;
+	struct {
+		u32 num_args:8;
+		u32 event_id:8;
+		u32 status:16;
+	};
+};
+
+struct slpc_event_output {
+	u32 reserved;
+	union slpc_event_output_header header;
+	u32 args[SLPC_EVENT_MAX_OUTPUT_ARGS];
+} __packed;
+
+enum slpc_event_id {
+	SLPC_EVENT_RESET = 0,
+	SLPC_EVENT_SHUTDOWN = 1,
+	SLPC_EVENT_PLATFORM_INFO_CHANGE = 2,
+	SLPC_EVENT_DISPLAY_MODE_CHANGE = 3,
+	SLPC_EVENT_FLIP_COMPLETE = 4,
+	SLPC_EVENT_QUERY_TASK_STATE = 5,
+	SLPC_EVENT_PARAMETER_SET = 6,
+	SLPC_EVENT_PARAMETER_UNSET = 7,
+};
+
+#define SLPC_EVENT(id, argc)	((u32) (id) << 8 | (argc))
+
+enum slpc_status {
+	SLPC_STATUS_OK = 0,
+	SLPC_STATUS_ERROR = 1,
+	SLPC_STATUS_ILLEGAL_COMMAND = 2,
+	SLPC_STATUS_INVALID_ARGS = 3,
+	SLPC_STATUS_INVALID_PARAMS = 4,
+	SLPC_STATUS_INVALID_DATA = 5,
+	SLPC_STATUS_OUT_OF_RANGE = 6,
+	SLPC_STATUS_NOT_SUPPORTED = 7,
+	SLPC_STATUS_NOT_IMPLEMENTED = 8,
+	SLPC_STATUS_NO_DATA = 9,
+	SLPC_STATUS_EVENT_NOT_REGISTERED = 10,
+	SLPC_STATUS_REGISTER_LOCKED = 11,
+	SLPC_STATUS_TEMPORARILY_UNAVAILABLE = 12,
+	SLPC_STATUS_VALUE_ALREADY_SET = 13,
+	SLPC_STATUS_VALUE_ALREADY_UNSET = 14,
+	SLPC_STATUS_VALUE_NOT_CHANGED = 15,
+	SLPC_STATUS_MEMIO_ERROR = 16,
+	SLPC_STATUS_EVENT_QUEUED_REQ_DPC = 17,
+	SLPC_STATUS_EVENT_QUEUED_NOREQ_DPC = 18,
+	SLPC_STATUS_NO_EVENT_QUEUED = 19,
+	SLPC_STATUS_OUT_OF_SPACE = 20,
+	SLPC_STATUS_TIMEOUT = 21,
+	SLPC_STATUS_NO_LOCK = 22,
+};
+
 /* intel_slpc.c */
 void intel_slpc_init(struct drm_i915_private *dev_priv);
 void intel_slpc_cleanup(struct drm_i915_private *dev_priv);
-- 
1.9.1