RE: [PATCH] clk: imx: clk-fracn-gppll: Return rate in rate table properly in ->recalc_rate()

From: Peng Fan
Date: Sun May 29 2022 - 22:08:14 EST


> Subject: [PATCH] clk: imx: clk-fracn-gppll: Return rate in rate table properly in
> ->recalc_rate()
>
> The PLL parameters in rate table should be directly compared with those read
> from PLL registers instead of the cooked ones.
>
> Fixes: 1b26cb8a77a4 ("clk: imx: support fracn gppll")
> Cc: Abel Vesa <abel.vesa@xxxxxxx>
> Cc: Michael Turquette <mturquette@xxxxxxxxxxxx>
> Cc: Stephen Boyd <sboyd@xxxxxxxxxx>
> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
> Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
> Cc: Fabio Estevam <festevam@xxxxxxxxx>
> Cc: NXP Linux Team <linux-imx@xxxxxxx>
> Cc: Peng Fan <peng.fan@xxxxxxx>
> Signed-off-by: Liu Ying <victor.liu@xxxxxxx>

Reviewed-by: Peng Fan <peng.fan@xxxxxxx>

> ---
> drivers/clk/imx/clk-fracn-gppll.c | 24 +++++++++++++-----------
> 1 file changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/clk/imx/clk-fracn-gppll.c b/drivers/clk/imx/clk-fracn-gppll.c
> index 71c102d950ab..762b07dd5a6d 100644
> --- a/drivers/clk/imx/clk-fracn-gppll.c
> +++ b/drivers/clk/imx/clk-fracn-gppll.c
> @@ -131,18 +131,7 @@ static unsigned long
> clk_fracn_gppll_recalc_rate(struct clk_hw *hw, unsigned lon
> mfi = FIELD_GET(PLL_MFI_MASK, pll_div);
>
> rdiv = FIELD_GET(PLL_RDIV_MASK, pll_div);
> - rdiv = rdiv + 1;
> odiv = FIELD_GET(PLL_ODIV_MASK, pll_div);
> - switch (odiv) {
> - case 0:
> - odiv = 2;
> - break;
> - case 1:
> - odiv = 3;
> - break;
> - default:
> - break;
> - }
>
> /*
> * Sometimes, the recalculated rate has deviation due to @@ -160,6
> +149,19 @@ static unsigned long clk_fracn_gppll_recalc_rate(struct clk_hw
> *hw, unsigned lon
> if (rate)
> return (unsigned long)rate;
>
> + rdiv = rdiv + 1;
> +
> + switch (odiv) {
> + case 0:
> + odiv = 2;
> + break;
> + case 1:
> + odiv = 3;
> + break;
> + default:
> + break;
> + }
> +
> /* Fvco = Fref * (MFI + MFN / MFD) */
> fvco = fvco * mfi * mfd + fvco * mfn;
> do_div(fvco, mfd * rdiv * odiv);
> --
> 2.25.1