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From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Sibi Sankar <quic_sibis@quicinc.com>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>
Cc:     linux-arm-msm@vger.kernel.org, linux-remoteproc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] remoteproc: qcom: q6v5: Add interconnect path proxy vote
Date:   Thu, 24 Feb 2022 19:32:24 -0800
Message-Id: <20220225033224.2238425-1-bjorn.andersson@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Many remoteproc instances requires that Linux casts a proxy vote for an
interconnect path during boot, until they can do it themselves. Add
support for voting for a single path.

As this is a shared problem between both PAS and MSS drivers, the path
is acquired and votes casted from the common helper code.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Sibi posted recently a patch to add interconnect votes from the modem driver,
today I needed the same feature for one of the PAS remoteprocs. After
essentially duplicating Sibi's patch I realized that it doesn't look too bad to
put this in the common Q6V5 code.

The main difference is that this would be messy if we need to support multiple
paths, so we probably would have to push it out to the individual drivers at
that point.

Sibi's patch can be found here.
https://lore.kernel.org/all/1644813252-12897-3-git-send-email-quic_sibis@quicinc.com/


This makes the implementation pick up one path, relevant DT bindings would
still need to be updated in order be allowed to this in the DeviceTree files.

 drivers/remoteproc/qcom_q6v5.c | 21 ++++++++++++++++++++-
 drivers/remoteproc/qcom_q6v5.h |  3 +++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/qcom_q6v5.c b/drivers/remoteproc/qcom_q6v5.c
index 442a388f8102..5280ec9b5449 100644
--- a/drivers/remoteproc/qcom_q6v5.c
+++ b/drivers/remoteproc/qcom_q6v5.c
@@ -8,6 +8,7 @@
  */
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
+#include <linux/interconnect.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/soc/qcom/qcom_aoss.h>
@@ -51,9 +52,17 @@ int qcom_q6v5_prepare(struct qcom_q6v5 *q6v5)
 {
 	int ret;
 
+	ret = icc_set_bw(q6v5->path, 0, UINT_MAX);
+	if (ret < 0) {
+		dev_err(q6v5->dev, "failed to set bandwidth request\n");
+		return ret;
+	}
+
 	ret = q6v5_load_state_toggle(q6v5, true);
-	if (ret)
+	if (ret) {
+		icc_set_bw(q6v5->path, 0, 0);
 		return ret;
+	}
 
 	reinit_completion(&q6v5->start_done);
 	reinit_completion(&q6v5->stop_done);
@@ -78,6 +87,9 @@ int qcom_q6v5_unprepare(struct qcom_q6v5 *q6v5)
 	disable_irq(q6v5->handover_irq);
 	q6v5_load_state_toggle(q6v5, false);
 
+	/* Disable interconnect vote, in case handover never happened */
+	icc_set_bw(q6v5->path, 0, 0);
+
 	return !q6v5->handover_issued;
 }
 EXPORT_SYMBOL_GPL(qcom_q6v5_unprepare);
@@ -160,6 +172,8 @@ static irqreturn_t q6v5_handover_interrupt(int irq, void *data)
 	if (q6v5->handover)
 		q6v5->handover(q6v5);
 
+	icc_set_bw(q6v5->path, 0, 0);
+
 	q6v5->handover_issued = true;
 
 	return IRQ_HANDLED;
@@ -332,6 +346,11 @@ int qcom_q6v5_init(struct qcom_q6v5 *q6v5, struct platform_device *pdev,
 		return load_state ? -ENOMEM : -EINVAL;
 	}
 
+	q6v5->path = devm_of_icc_get(&pdev->dev, NULL);
+	if (IS_ERR(q6v5->path))
+		return dev_err_probe(&pdev->dev, PTR_ERR(q6v5->path),
+				     "failed to acquire interconnect path\n");
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(qcom_q6v5_init);
diff --git a/drivers/remoteproc/qcom_q6v5.h b/drivers/remoteproc/qcom_q6v5.h
index f35e04471ed7..5a859c41896e 100644
--- a/drivers/remoteproc/qcom_q6v5.h
+++ b/drivers/remoteproc/qcom_q6v5.h
@@ -7,6 +7,7 @@
 #include <linux/completion.h>
 #include <linux/soc/qcom/qcom_aoss.h>
 
+struct icc_path;
 struct rproc;
 struct qcom_smem_state;
 struct qcom_sysmon;
@@ -18,6 +19,8 @@ struct qcom_q6v5 {
 	struct qcom_smem_state *state;
 	struct qmp *qmp;
 
+	struct icc_path *path;
+
 	unsigned stop_bit;
 
 	int wdog_irq;
-- 
2.33.1