From df79e2b48baa2f3434645b0c74cda01d67a126e7 Mon Sep 17 00:00:00 2001 From: Sean Anderson Date: Fri, 11 Jun 2021 00:16:12 -0400 Subject: [PATCH] clk: k210: Don't set PLL rates if we are already at the correct rate This speeds up boot by preventing multiple reconfigurations of the PLLs. Signed-off-by: Sean Anderson Reviewed-by: Leo Yu-Chi Liang --- drivers/clk/kendryte/clk.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/clk/kendryte/clk.c b/drivers/clk/kendryte/clk.c index a2901f9b96..3148756968 100644 --- a/drivers/clk/kendryte/clk.c +++ b/drivers/clk/kendryte/clk.c @@ -847,21 +847,22 @@ static ulong k210_pll_set_rate(struct k210_clk_priv *priv, int id, ulong rate, const struct k210_pll_params *pll = &k210_plls[id]; struct k210_pll_config config = {}; u32 reg; + ulong calc_rate; if (rate_in < 0) return rate_in; - log_debug("Calculating parameters with rate=%lu and rate_in=%lu\n", - rate, rate_in); err = k210_pll_calc_config(rate, rate_in, &config); if (err) return err; log_debug("Got r=%u f=%u od=%u\n", config.r, config.f, config.od); - /* - * Don't use clk_disable as it might not actually disable the pll due to - * refcounting - */ + /* Don't bother setting the rate if we're already at that rate */ + calc_rate = DIV_ROUND_DOWN_ULL(((u64)rate_in) * config.f, + config.r * config.od); + if (calc_rate == k210_pll_get_rate(priv, id, rate)) + return calc_rate; + k210_pll_disable(priv, id); reg = readl(priv->base + pll->off); @@ -875,7 +876,7 @@ static ulong k210_pll_set_rate(struct k210_clk_priv *priv, int id, ulong rate, | FIELD_PREP(K210_PLL_BWADJ, config.f - 1); writel(reg, priv->base + pll->off); - err = k210_pll_enable(priv, id); + k210_pll_enable(priv, id); serial_setbrg(); return k210_pll_get_rate(priv, id, rate); -- 2.39.5