linux-kernel - [PATCH 04/20] clk: qcom: smd-rpm: Export clock scaling availability

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Message-Id: <20230526-topic-smd_icc-v1-4-1bf8e6663c4e@linaro.org>
Date:   Tue, 30 May 2023 12:20:03 +0200
From:   Konrad Dybcio <konrad.dybcio@...aro.org>
To:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Georgi Djakov <djakov@...nel.org>,
        Leo Yan <leo.yan@...aro.org>, Evan Green <evgreen@...omium.org>
Cc:     Marijn Suijten <marijn.suijten@...ainline.org>,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-clk@...r.kernel.org, linux-pm@...r.kernel.org,
        Konrad Dybcio <konrad.dybcio@...aro.org>
Subject: [PATCH 04/20] clk: qcom: smd-rpm: Export clock scaling
 availability

Before we issue a call to RPM through clk_smd_rpm_enable_scaling() the
clock rate requests will not be commited in hardware. This poses a
race threat since we're accessing the bus clocks directly from within
the interconnect framework.

Add a marker to indicate that we're good to go with sending new requests
and export it so that it can be referenced from icc.

Signed-off-by: Konrad Dybcio <konrad.dybcio@...aro.org>
---
 drivers/clk/qcom/clk-smd-rpm.c   | 9 +++++++++
 include/linux/soc/qcom/smd-rpm.h | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/drivers/clk/qcom/clk-smd-rpm.c b/drivers/clk/qcom/clk-smd-rpm.c
index b63f946e4520..f8f5977408e0 100644
--- a/drivers/clk/qcom/clk-smd-rpm.c
+++ b/drivers/clk/qcom/clk-smd-rpm.c
@@ -151,6 +151,7 @@
 #define to_clk_smd_rpm(_hw) container_of(_hw, struct clk_smd_rpm, hw)
 
 static struct qcom_smd_rpm *rpmcc_smd_rpm;
+static bool smd_rpm_clk_scaling;
 
 struct clk_smd_rpm {
 	const int rpm_res_type;
@@ -393,6 +394,12 @@ static unsigned long clk_smd_rpm_recalc_rate(struct clk_hw *hw,
 	return r->rate;
 }
 
+bool qcom_smd_rpm_scaling_available(void)
+{
+	return smd_rpm_clk_scaling;
+}
+EXPORT_SYMBOL_GPL(qcom_smd_rpm_scaling_available);
+
 static int clk_smd_rpm_enable_scaling(void)
 {
 	int ret;
@@ -418,6 +425,8 @@ static int clk_smd_rpm_enable_scaling(void)
 		return ret;
 	}
 
+	smd_rpm_clk_scaling = true;
+
 	pr_debug("%s: RPM clock scaling is enabled\n", __func__);
 	return 0;
 }
diff --git a/include/linux/soc/qcom/smd-rpm.h b/include/linux/soc/qcom/smd-rpm.h
index 8190878645f9..420f6c79d535 100644
--- a/include/linux/soc/qcom/smd-rpm.h
+++ b/include/linux/soc/qcom/smd-rpm.h
@@ -65,4 +65,6 @@ int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
 		       u32 resource_type, u32 resource_id,
 		       void *buf, size_t count);
 
+bool qcom_smd_rpm_scaling_available(void);
+
 #endif

-- 
2.40.1