Re: [PATCH v2] clk-rcar-gen2: ADSP clock support

From: Geert Uytterhoeven
Date: Mon Jan 05 2015 - 08:14:04 EST


Hi Sergei,

On Tue, Dec 30, 2014 at 9:51 PM, Sergei Shtylyov
<sergei.shtylyov@xxxxxxxxxxxxxxxxxx> wrote:
> Add the ADSP clock support to the R-Car generation 2 CPG driver. This clock
> gets derived from PLL1. The layout of the ADSPCKCR register is similar to
> those of the clocks supported by the 'clk-div6' driver but the divider encoding
> is non-linear, so can't be supported by that driver...
>
> Based on the original patch by Konstantin Kozhevnikov
> <konstantin.kozhevnikov@xxxxxxxxxxxxxxxxxx>.
>
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
>
> ---
> The patch is against the 'clk-next' branch of Mike Turquette's 'linux.git' repo
> plus the RCAN clock support patch posted last week.
>
> Changes in version 2:
> - swapped "adsp" and "rcan" in the binding document.

> +++ linux/drivers/clk/shmobile/clk-rcar-gen2.c
> @@ -33,6 +33,7 @@ struct rcar_gen2_cpg {
> #define CPG_FRQCRC 0x000000e0
> #define CPG_FRQCRC_ZFC_MASK (0x1f << 8)
> #define CPG_FRQCRC_ZFC_SHIFT 8
> +#define CPG_ADSPCKCR 0x0000025c
> #define CPG_RCANCKCR 0x00000270
>
> /* -----------------------------------------------------------------------------
> @@ -162,6 +163,51 @@ static struct clk * __init cpg_z_clk_reg
> return clk;
> }
>
> +/* ADSP divisors */
> +static const struct clk_div_table cpg_adsp_div_table[] = {
> + { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 },
> + { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 },
> + { 10, 36 }, { 11, 48 }, { 0, 0 },
> +};
> +
> +static struct clk * __init cpg_adsp_clk_register(struct rcar_gen2_cpg *cpg)
> +{
> + const char *parent_name = "pll1";
> + struct clk_divider *div;
> + struct clk_gate *gate;
> + struct clk *clk;
> +
> + div = kzalloc(sizeof(*div), GFP_KERNEL);
> + if (!div)
> + return ERR_PTR(-ENOMEM);
> +
> + div->reg = cpg->reg + CPG_ADSPCKCR;
> + div->width = 4;
> + div->table = cpg_adsp_div_table;
> + div->lock = &cpg->lock;
> +
> + gate = kzalloc(sizeof(*gate), GFP_KERNEL);
> + if (!gate) {
> + kfree(div);
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + gate->reg = cpg->reg + CPG_RCANCKCR;

Shouldn't this be CPG_ADSPCKCR?

> + gate->bit_idx = 8;
> + gate->flags = CLK_GATE_SET_TO_DISABLE;
> + gate->lock = &cpg->lock;
> +
> + clk = clk_register_composite(NULL, "adsp", &parent_name, 1, NULL, NULL,
> + &div->hw, &clk_divider_ops,
> + &gate->hw, &clk_gate_ops, 0);
> + if (IS_ERR(clk)) {
> + kfree(gate);
> + kfree(div);
> + }
> +
> + return clk;
> +}

Please insert the adsp code after the rcan code, to match the clock order
in bindings and #defines.

> +
> static struct clk * __init cpg_rcan_clk_register(struct rcar_gen2_cpg *cpg,
> struct device_node *np)
> {
> @@ -301,6 +347,8 @@ rcar_gen2_cpg_register_clock(struct devi
> shift = 0;
> } else if (!strcmp(name, "z")) {
> return cpg_z_clk_register(cpg);
> + } else if (!strcmp(name, "adsp")) {
> + return cpg_adsp_clk_register(cpg);

Please insert the adsp code after the rcan code.

> } else if (!strcmp(name, "rcan")) {
> return cpg_rcan_clk_register(cpg, np);
> } else {

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
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