2023-09-12 07:33:54

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 15/37] clk: renesas: rzg2l: add support for RZ/G3S PLL

From: Claudiu Beznea <[email protected]>

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 <[email protected]>
---
drivers/clk/renesas/rzg2l-cpg.c | 44 ++++++++++++++++++++++++++++++---
drivers/clk/renesas/rzg2l-cpg.h | 3 +++
2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c
index 50f69bbe1a6e..638501e493e2 100644
--- 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);
+ /* 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;
+ return DIV_ROUND_CLOSEST_ULL(rate, (mr + pr));
+}
+
+static const struct clk_ops rzg3s_cpg_pll_ops = {
+ .recalc_rate = rzg3s_cpg_pll_clk_recalc_rate,
+};
+
static struct clk * __init
rzg2l_cpg_pll_clk_register(const struct cpg_core_clk *core,
struct clk **clks,
void __iomem *base,
- struct rzg2l_cpg_priv *priv)
+ struct rzg2l_cpg_priv *priv,
+ const struct clk_ops *ops)
{
struct device *dev = priv->dev;
const struct clk *parent;
@@ -740,7 +772,7 @@ rzg2l_cpg_pll_clk_register(const struct cpg_core_clk *core,

parent_name = __clk_get_name(parent);
init.name = core->name;
- init.ops = &rzg2l_cpg_pll_ops;
+ init.ops = ops;
init.flags = 0;
init.parent_names = &parent_name;
init.num_parents = 1;
@@ -835,8 +867,12 @@ rzg2l_cpg_register_core_clk(const struct cpg_core_clk *core,
core->mult, div);
break;
case CLK_TYPE_SAM_PLL:
- clk = rzg2l_cpg_pll_clk_register(core, priv->clks,
- priv->base, priv);
+ clk = rzg2l_cpg_pll_clk_register(core, priv->clks, priv->base, priv,
+ &rzg2l_cpg_pll_ops);
+ break;
+ case CLK_TYPE_G3S_SAM_PLL:
+ clk = rzg2l_cpg_pll_clk_register(core, priv->clks, priv->base, priv,
+ &rzg3s_cpg_pll_ops);
break;
case CLK_TYPE_SIPLL5:
clk = rzg2l_cpg_sipll5_register(core, priv->clks, priv);
diff --git a/drivers/clk/renesas/rzg2l-cpg.h b/drivers/clk/renesas/rzg2l-cpg.h
index 0b28870a6f9d..16f7a1872814 100644
--- 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,

/* 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_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) \
--
2.39.2


2023-09-14 14:08:29

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [PATCH 15/37] clk: renesas: rzg2l: add support for RZ/G3S PLL

Hi Claudiu,

On Tue, Sep 12, 2023 at 6:52 AM Claudiu <[email protected]> wrote:
> From: Claudiu Beznea <[email protected]>
>
> 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 <[email protected]>

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 -- [email protected]

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