Commit dac5d672 authored Mar 05, 2019 by James Liao Committed by Stephen Boyd Apr 11, 2019

clk: mediatek: Allow changing PLL rate when it is off



Some modules may need to change its clock rate before turn on it.
So changing PLL's rate when it is off should be allowed.
This patch removes PLL enabled check before set rate, so that
PLLs can set new frequency even if they are off.

On MT8173 for example, ARMPLL's enable bit can be controlled by
other HW. That means ARMPLL may be turned on even if we (CPU / SW)
set ARMPLL's enable bit as 0. In this case, SW may want and can
still change ARMPLL's rate by changing its pcw and postdiv settings.
But without this patch, new pcw setting will not be applied because
its enable bit is 0.

Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Acked-by: Michael Turquette <mturuqette@baylibre.com>
Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
Reviewed-by: James Liao <jamesjj.liao@mediatek.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

parent acddfc2c

drivers/clk/mediatek/clk-pll.c

+2 −11

Original line number	Diff line number	Diff line
		@@ -124,9 +124,6 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
		int postdiv)
		{
		u32 chg, val;
		int pll_en;

		pll_en = readl(pll->base_addr + REG_CON0) & CON0_BASE_EN;

		/* disable tuner */
		__mtk_pll_tuner_disable(pll);
		@@ -147,12 +144,7 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
		pll->data->pcw_shift);
		val \|= pcw << pll->data->pcw_shift;
		writel(val, pll->pcw_addr);

		chg = readl(pll->pcw_chg_addr);

		if (pll_en)
		chg \|= PCW_CHG_MASK;

		chg = readl(pll->pcw_chg_addr) \| PCW_CHG_MASK;
		writel(chg, pll->pcw_chg_addr);
		if (pll->tuner_addr)
		writel(val + 1, pll->tuner_addr);
		@@ -160,7 +152,6 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
		/* restore tuner_en */
		__mtk_pll_tuner_enable(pll);

		if (pll_en)
		udelay(20);
		}

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