drm/msm/a6xx: Send ACD state to QMP at GMU resume

The QMP mailbox expects to be notified of the ACD (Adaptive Clock
Distribution) state. Get a handle to the mailbox at probe time and
poke it at GMU resume.

Since we don't fully support ACD yet, hardcode the message to "val: 0"
(state = disabled).

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # sm8450
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/559287/Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/adreno/a6xx_gmu.c

@@ -989,6 +989,14 @@ int a6xx_gmu_resume(struct a6xx_gpu *a6xx_gpu)
 
 	gmu->hung = false;
 
+	/* Notify AOSS about the ACD state (unimplemented for now => disable it) */
+	if (!IS_ERR(gmu->qmp)) {
+		ret = qmp_send(gmu->qmp, "{class: gpu, res: acd, val: %d}",
+			       0 /* Hardcode ACD to be disabled for now */);
+		if (ret)
+			dev_err(gmu->dev, "failed to send GPU ACD state\n");
+	}
+
 	/* Turn on the resources */
 	pm_runtime_get_sync(gmu->dev);
 
@@ -1741,6 +1749,10 @@ int a6xx_gmu_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
 		goto detach_cxpd;
 	}
 
+	gmu->qmp = qmp_get(gmu->dev);
+	if (IS_ERR(gmu->qmp) && adreno_is_a7xx(adreno_gpu))
+		return PTR_ERR(gmu->qmp);
+
 	init_completion(&gmu->pd_gate);
 	complete_all(&gmu->pd_gate);
 	gmu->pd_nb.notifier_call = cxpd_notifier_cb;
@@ -1764,6 +1776,9 @@ int a6xx_gmu_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
 
 	return 0;
 
+	if (!IS_ERR_OR_NULL(gmu->qmp))
+		qmp_put(gmu->qmp);
+
 detach_cxpd:
 	dev_pm_domain_detach(gmu->cxpd, false);
 

drivers/gpu/drm/msm/adreno/a6xx_gmu.h

@@ -8,6 +8,7 @@
 #include <linux/iopoll.h>
 #include <linux/interrupt.h>
 #include <linux/notifier.h>
+#include <linux/soc/qcom/qcom_aoss.h>
 #include "msm_drv.h"
 #include "a6xx_hfi.h"
 
@@ -96,6 +97,8 @@ struct a6xx_gmu {
 	/* For power domain callback */
 	struct notifier_block pd_nb;
 	struct completion pd_gate;
+
+	struct qmp *qmp;
 };
 
 static inline u32 gmu_read(struct a6xx_gmu *gmu, u32 offset)