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From:   Ansuel Smith <ansuelsmth@gmail.com>
To:     Rob Herring <robh+dt@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Andy Gross <agross@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Ansuel Smith <ansuelsmth@gmail.com>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org
Subject: [PATCH v6 12/18] clk: qcom: clk-krait: add apq/ipq8064 errata workaround
Date:   Tue, 22 Mar 2022 00:15:42 +0100
Message-Id: <20220321231548.14276-13-ansuelsmth@gmail.com>
In-Reply-To: <20220321231548.14276-1-ansuelsmth@gmail.com>
References: <20220321231548.14276-1-ansuelsmth@gmail.com>
MIME-Version: 1.0
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Add apq/ipq8064 errata workaround where the sec_src clock gating needs to
be disabled during switching. To enable this set disable_sec_src_gating
in the mux struct.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
 drivers/clk/qcom/clk-krait.c | 16 ++++++++++++++++
 drivers/clk/qcom/clk-krait.h |  1 +
 drivers/clk/qcom/krait-cc.c  |  1 +
 3 files changed, 18 insertions(+)

diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c
index b6b7650dbf15..7ba5dbc72bce 100644
--- a/drivers/clk/qcom/clk-krait.c
+++ b/drivers/clk/qcom/clk-krait.c
@@ -18,13 +18,23 @@
 static DEFINE_SPINLOCK(krait_clock_reg_lock);
 
 #define LPL_SHIFT	8
+#define SECCLKAGD	BIT(4)
+
 static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel)
 {
 	unsigned long flags;
 	u32 regval;
 
 	spin_lock_irqsave(&krait_clock_reg_lock, flags);
+
 	regval = krait_get_l2_indirect_reg(mux->offset);
+
+	/* apq/ipq8064 Errata: disable sec_src clock gating during switch. */
+	if (mux->disable_sec_src_gating) {
+		regval |= SECCLKAGD;
+		krait_set_l2_indirect_reg(mux->offset, regval);
+	}
+
 	regval &= ~(mux->mask << mux->shift);
 	regval |= (sel & mux->mask) << mux->shift;
 	if (mux->lpl) {
@@ -33,6 +43,12 @@ static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel)
 	}
 	krait_set_l2_indirect_reg(mux->offset, regval);
 
+	/* apq/ipq8064 Errata: re-enabled sec_src clock gating. */
+	if (mux->disable_sec_src_gating) {
+		regval &= ~SECCLKAGD;
+		krait_set_l2_indirect_reg(mux->offset, regval);
+	}
+
 	/* Wait for switch to complete. */
 	mb();
 	udelay(1);
diff --git a/drivers/clk/qcom/clk-krait.h b/drivers/clk/qcom/clk-krait.h
index 9120bd2f5297..f930538c539e 100644
--- a/drivers/clk/qcom/clk-krait.h
+++ b/drivers/clk/qcom/clk-krait.h
@@ -15,6 +15,7 @@ struct krait_mux_clk {
 	u8		safe_sel;
 	u8		old_index;
 	bool		reparent;
+	bool		disable_sec_src_gating;
 
 	struct clk_hw	hw;
 	struct notifier_block   clk_nb;
diff --git a/drivers/clk/qcom/krait-cc.c b/drivers/clk/qcom/krait-cc.c
index 299eb4c81d96..cb8b267f1dc5 100644
--- a/drivers/clk/qcom/krait-cc.c
+++ b/drivers/clk/qcom/krait-cc.c
@@ -157,6 +157,7 @@ krait_add_sec_mux(struct device *dev, struct clk *qsb, int id,
 	mux->shift = 2;
 	mux->parent_map = sec_mux_map;
 	mux->hw.init = &init;
+	mux->disable_sec_src_gating = true;
 
 	init.name = kasprintf(GFP_KERNEL, "krait%s_sec_mux", s);
 	if (!init.name)
-- 
2.34.1