linux-kernel - [PATCH 05/53] interconnect: qcom: icc-rpmh: Implement voting on non-APPS RSCs

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Message-Id: <20230708-topic-rpmh_icc_rsc-v1-5-b223bd2ac8dd@linaro.org>
Date:   Tue, 11 Jul 2023 14:18:04 +0200
From:   Konrad Dybcio <konrad.dybcio@...aro.org>
To:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Georgi Djakov <djakov@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        cros-qcom-dts-watchers@...omium.org
Cc:     Marijn Suijten <marijn.suijten@...ainline.org>,
        linux-arm-msm@...r.kernel.org, linux-pm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        Konrad Dybcio <konrad.dybcio@...aro.org>
Subject: [PATCH 05/53] interconnect: qcom: icc-rpmh: Implement voting on
 non-APPS RSCs

Linux can cast votes on resources through different RSCs (e.g. DISP). This
can be done for many reasons, from latency to fine-grain on-SoC-power-grid
management.

With all the necessary bits in place, add the loops and ifs necessary to
vote through different RSCs.

Signed-off-by: Konrad Dybcio <konrad.dybcio@...aro.org>
---
 drivers/interconnect/qcom/icc-rpmh.c | 49 ++++++++++++++++++++++++++++++------
 1 file changed, 42 insertions(+), 7 deletions(-)

diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
index 53298148f24b..3cdd9106b0c0 100644
--- a/drivers/interconnect/qcom/icc-rpmh.c
+++ b/drivers/interconnect/qcom/icc-rpmh.c
@@ -22,6 +22,8 @@ void qcom_icc_pre_aggregate(struct icc_node *node)
 {
 	struct qcom_icc_provider *qp;
 	struct qcom_icc_node *qn;
+	struct qcom_icc_bcm *bcm;
+	int voter_idx;
 	int i;
 
 	qn = node->data;
@@ -32,8 +34,17 @@ void qcom_icc_pre_aggregate(struct icc_node *node)
 		qn->max_peak[i] = 0;
 	}
 
-	for (i = 0; i < qn->num_bcms; i++)
-		qcom_icc_bcm_voter_add(qcom_icc_bcm_voters[ICC_BCM_VOTER_APPS], qn->bcms[i]);
+	for (i = 0; i < qn->num_bcms; i++) {
+		bcm = qn->bcms[i];
+
+		/* Old and incomplete device trees may not specify all voters. */
+		if (qcom_icc_bcm_voters[bcm->voter_idx])
+			voter_idx = bcm->voter_idx;
+		else
+			voter_idx = ICC_BCM_VOTER_APPS;
+
+		qcom_icc_bcm_voter_add(qcom_icc_bcm_voters[voter_idx], bcm);
+	}
 }
 EXPORT_SYMBOL_GPL(qcom_icc_pre_aggregate);
 
@@ -87,6 +98,7 @@ int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
 {
 	struct qcom_icc_provider *qp;
 	struct icc_node *node;
+	int i, ret;
 
 	if (!src)
 		node = dst;
@@ -95,7 +107,11 @@ int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
 
 	qp = to_qcom_provider(node->provider);
 
-	qcom_icc_bcm_voter_commit(qcom_icc_bcm_voters[ICC_BCM_VOTER_APPS]);
+	for (i = 0; i < ICC_BCM_VOTER_MAX; i++) {
+		ret = qcom_icc_bcm_voter_commit(qcom_icc_bcm_voters[i]);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }
@@ -168,6 +184,7 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
 	struct qcom_icc_node * const *qnodes, *qn;
 	struct qcom_icc_provider *qp;
 	struct device_node *bcm_node;
+	u32 val, voter_count = 0;
 	struct icc_node *node;
 	size_t num_nodes, i, j;
 	int ret;
@@ -201,10 +218,28 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
 	qp->bcms = desc->bcms;
 	qp->num_bcms = desc->num_bcms;
 
-	/* Ensure the BCM voter is reachable (unless we don't have any) */
-	qp->voter = qcom_icc_bcm_voters[ICC_BCM_VOTER_APPS];
-	if (qp->num_bcms && !qp->voter)
-		return -EPROBE_DEFER;
+	for (i = 0; i < ICC_BCM_VOTER_MAX; i++) {
+		bcm_node = of_parse_phandle(dev->of_node, "qcom,bcm-voters", voter_count);
+		if (!bcm_node)
+			break;
+
+		voter_count++;
+
+		ret = of_property_read_u32(bcm_node, "qcom,bcm-voter-idx", &val);
+		of_node_put(bcm_node);
+		/* Legacy DTs only ever referenced the APPS BCM voter */
+		if (ret == -EINVAL)
+			val = ICC_BCM_VOTER_APPS;
+		else if (ret)
+			return ret;
+
+		if (!qcom_icc_bcm_voters[val])
+			return -EPROBE_DEFER;
+	}
+
+	/* Let's not forget to add qcom,bcm-voters to the provider node! */
+	if (qp->num_bcms && !voter_count)
+		return -EINVAL;
 
 	for (i = 0; i < qp->num_bcms; i++)
 		qcom_icc_bcm_init(qp->bcms[i], dev);

-- 
2.41.0