[PATCH v2 08/11] drm/msm: adreno: request for maximum bus bandwidth usage

[Neil Armstrong]

When requesting a DDR bandwidth level along a GPU frequency
level via the GMU, we can also specify the bus bandwidth usage in a 16bit
quantitized value.

For now simply request the maximum bus usage.

Signed-off-by: Neil Armstrong <neil.armstrong at linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 11 +++++++++++
 drivers/gpu/drm/msm/adreno/a6xx_hfi.h |  5 +++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index dc2d0035544e7848e5c4ea27f1ea9a191f9c4991..36c0f67fd8e109aabf09a0804bacbed3593c39d7 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -134,6 +134,17 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
 			if (bw == gmu->gpu_bw_table[bw_index])
 				break;
 		}
+
+		if (bw_index) {
+			/*
+			 * Append AB vote to the maximum bus usage.
+			 * AB represents a quantitized 16bit value of the
+			 * max ddr bandwidth we could use, let's simply
+			 * request the maximum for now.
+			 */
+			bw_index |= AB_VOTE(MAX_AB_VOTE);
+			bw_index |= AB_VOTE_ENABLE;
+		}
 	}
 
 	gmu->current_perf_index = perf_index;
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_hfi.h b/drivers/gpu/drm/msm/adreno/a6xx_hfi.h
index 528110169398f69f16443a29a1594d19c36fb595..52ba4a07d7b9a709289acd244a751ace9bdaab5d 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.h
@@ -173,6 +173,11 @@ struct a6xx_hfi_gx_bw_perf_vote_cmd {
 	u32 bw;
 };
 
+#define AB_VOTE_MASK		GENMASK(31, 16)
+#define MAX_AB_VOTE		(FIELD_MAX(AB_VOTE_MASK) - 1)
+#define AB_VOTE(vote)		FIELD_PREP(AB_VOTE_MASK, (vote))
+#define AB_VOTE_ENABLE		BIT(8)
+
 #define HFI_H2F_MSG_PREPARE_SLUMBER 33
 
 struct a6xx_hfi_prep_slumber_cmd {

-- 
2.34.1