clk: qcom: clk-krait: add apq/ipq8064 errata workaround

Add apq/ipq8064 errata workaround where the sec_src clock gating needs to
be disabled during switching. krait-cc compatible is not enough to
handle this and limit this workaround to apq/ipq8064. We check machine
compatible to handle this.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220430054458.31321-4-ansuelsmth@gmail.com

diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c
index 9004642..45da736 100644 (file)
--- 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 9120bd2..f930538 100644 (file)
--- 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 4d4b657..cfd961d 100644 (file)
--- a/drivers/clk/qcom/krait-cc.c
+++ b/drivers/clk/qcom/krait-cc.c
@@ -139,6 +139,14 @@ krait_add_sec_mux(struct device *dev, int id, const char *s,
        mux->hw.init = &init;
        mux->safe_sel = 0;
 
+       /* Checking for qcom,krait-cc-v1 or qcom,krait-cc-v2 is not
+        * enough to limit this to apq/ipq8064. Directly check machine
+        * compatible to correctly handle this errata.
+        */
+       if (of_machine_is_compatible("qcom,ipq8064") ||
+           of_machine_is_compatible("qcom,apq8064"))
+               mux->disable_sec_src_gating = true;
+
        init.name = kasprintf(GFP_KERNEL, "krait%s_sec_mux", s);
        if (!init.name)
                return -ENOMEM;