Hi Claudiu,
On Tue, Sep 12, 2023 at 6:52 AM Claudiu <claudiu.beznea@xxxxxxxxx> wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>
> Add support for reading the frequency of PLL1/4/6 available on RZ/G3S.
> The computation formula for PLL frequency is as follows:
> Fout = (nir + nfr / 4096) * Fin / (mr * pr)
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
Thanks for your patch!
> --- a/drivers/clk/renesas/rzg2l-cpg.c
> +++ b/drivers/clk/renesas/rzg2l-cpg.c
> @@ -718,11 +718,43 @@ static const struct clk_ops rzg2l_cpg_pll_ops = {
> .recalc_rate = rzg2l_cpg_pll_clk_recalc_rate,
> };
>
> +static unsigned long rzg3s_cpg_pll_clk_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + struct pll_clk *pll_clk = to_pll(hw);
> + struct rzg2l_cpg_priv *priv = pll_clk->priv;
> + u32 nir, nfr, mr, pr, val;
> + u64 rate;
> +
> + if (pll_clk->type != CLK_TYPE_G3S_SAM_PLL)
> + return parent_rate;
> +
> + val = readl(priv->base + GET_REG_SAMPLL_CLK1(pll_clk->conf));
> +
> + pr = 1 << FIELD_GET(GENMASK(28, 26), val);
Please add defines for the various GENMASK(...) fields.
> + /* Hardware interprets values higher than 8 as p = 16. */
> + if (pr > 8)
> + pr = 16;
> +
> + mr = FIELD_GET(GENMASK(25, 22), val) + 1;
> + nir = FIELD_GET(GENMASK(21, 13), val) + 1;
> + nfr = FIELD_GET(GENMASK(12, 1), val);
> +
> + rate = DIV_ROUND_CLOSEST_ULL((u64)parent_rate * nfr, 4096);
> + rate += (u64)parent_rate * nir;
When rewriting the formula as:
Fout = (4096 * nir + nfr) * Fin / (4096 * mr * pr)
you can simplify to:
rate = mul_u64_u32_shr(parent_rate, 4096 * nir + nfr, 12);
> + return DIV_ROUND_CLOSEST_ULL(rate, (mr + pr));
mr * pr
> +}
> --- a/drivers/clk/renesas/rzg2l-cpg.h
> +++ b/drivers/clk/renesas/rzg2l-cpg.h
> @@ -102,6 +102,7 @@ enum clk_types {
> CLK_TYPE_IN, /* External Clock Input */
> CLK_TYPE_FF, /* Fixed Factor Clock */
> CLK_TYPE_SAM_PLL,
> + CLK_TYPE_G3S_SAM_PLL,
CLK_TYPE_G3S_PLL, as the documentation doesn't use SAM?
>
> /* Clock with divider */
> CLK_TYPE_DIV,
> @@ -129,6 +130,8 @@ enum clk_types {
> DEF_TYPE(_name, _id, _type, .parent = _parent)
> #define DEF_SAMPLL(_name, _id, _parent, _conf) \
> DEF_TYPE(_name, _id, CLK_TYPE_SAM_PLL, .parent = _parent, .conf = _conf)
> +#define DEF_G3S_SAMPLL(_name, _id, _parent, _conf) \
DEF_G3S_PLL
> + DEF_TYPE(_name, _id, CLK_TYPE_G3S_SAM_PLL, .parent = _parent, .conf = _conf)
> #define DEF_INPUT(_name, _id) \
> DEF_TYPE(_name, _id, CLK_TYPE_IN)
> #define DEF_FIXED(_name, _id, _parent, _mult, _div) \
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
