clk: stm32mp1: recalculate counter when switching freq

Because stgen is initialized with HSI clock, we need to
recalculate the counter when changing frequency.

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

diff --git a/drivers/clk/clk_stm32mp1.c b/drivers/clk/clk_stm32mp1.c
index 39eaf64..916f9f9 100644 (file)
--- a/drivers/clk/clk_stm32mp1.c
+++ b/drivers/clk/clk_stm32mp1.c
@@ -1469,10 +1469,15 @@ static void stgen_config(struct stm32mp1_clk_priv *priv)
        rate = stm32mp1_clk_get(priv, p);
 
        if (cntfid0 != rate) {
+               u64 counter;
+
                pr_debug("System Generic Counter (STGEN) update\n");
                clrbits_le32(stgenc + STGENC_CNTCR, STGENC_CNTCR_EN);
-               writel(0x0, stgenc + STGENC_CNTCVL);
-               writel(0x0, stgenc + STGENC_CNTCVU);
+               counter = (u64)readl(stgenc + STGENC_CNTCVL);
+               counter |= ((u64)(readl(stgenc + STGENC_CNTCVU))) << 32;
+               counter = lldiv(counter * (u64)rate, cntfid0);
+               writel((u32)counter, stgenc + STGENC_CNTCVL);
+               writel((u32)(counter >> 32), stgenc + STGENC_CNTCVU);
                writel(rate, stgenc + STGENC_CNTFID0);
                setbits_le32(stgenc + STGENC_CNTCR, STGENC_CNTCR_EN);