On Thu, Mar 17, 2016 at 12:04:25AM +0800, Vishnu Patekar wrote:
> AHB1 on A83T is similar to ahb1 on A31, except parents are different.
> clock index 0b1x is PLL6.
>
> Signed-off-by: Vishnu Patekar <vishnupatekar0510@xxxxxxxxx>
> Acked-by: Chen-Yu Tsai <wens@xxxxxxxx>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/clock/sunxi.txt | 1 +
> drivers/clk/sunxi/clk-sunxi.c | 76 +++++++++++++++++++++++
> 2 files changed, 77 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> index 834436f..cba9fe55 100644
> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> @@ -30,6 +30,7 @@ Required properties:
> "allwinner,sun6i-a31-ar100-clk" - for the AR100 on A31
> "allwinner,sun9i-a80-cpus-clk" - for the CPUS on A80
> "allwinner,sun6i-a31-ahb1-clk" - for the AHB1 clock on A31
> + "allwinner,sun8i-a83t-ahb1-clk" - for the AHB1 clock on A83T
> "allwinner,sun8i-h3-ahb2-clk" - for the AHB2 clock on H3
> "allwinner,sun6i-a31-ahb1-gates-clk" - for the AHB1 gates on A31
> "allwinner,sun8i-a23-ahb1-gates-clk" - for the AHB1 gates on A23
> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
> index 91de0a0..a7aab65 100644
> --- a/drivers/clk/sunxi/clk-sunxi.c
> +++ b/drivers/clk/sunxi/clk-sunxi.c
> @@ -344,6 +344,67 @@ static void sun6i_ahb1_recalc(struct factors_request *req)
> req->rate >>= req->p;
> }
>
> +#define SUN8I_A83T_AHB1_PARENT_PLL6 2
> +/**
> + * sun8i_a83t_get_ahb_factors() - calculates m, p factors for AHB
> + * AHB rate is calculated as follows
> + * rate = parent_rate >> p
> + *
> + * if parent is pll6, then
> + * parent_rate = pll6 rate / (m + 1)
> + */
> +
> +static void sun8i_a83t_get_ahb1_factors(struct factors_request *req)
> +{
> + u8 div, calcp, calcm = 1;
> +
> + /*
> + * clock can only divide, so we will never be able to achieve
> + * frequencies higher than the parent frequency
> + */
> + if (req->parent_rate && req->rate > req->parent_rate)
> + req->rate = req->parent_rate;
> +
> + div = DIV_ROUND_UP(req->parent_rate, req->rate);
> +
> + /* calculate pre-divider if parent is pll6 */
> + if (req->parent_index >= SUN8I_A83T_AHB1_PARENT_PLL6) {
> + if (div < 4)
> + calcp = 0;
> + else if (div / 2 < 4)
> + calcp = 1;
> + else if (div / 4 < 4)
> + calcp = 2;
> + else
> + calcp = 3;
> +
> + calcm = DIV_ROUND_UP(div, 1 << calcp);
> + } else {
> + calcp = __roundup_pow_of_two(div);
> + calcp = calcp > 3 ? 3 : calcp;
> + }
> +
> + req->rate = (req->parent_rate / calcm) >> calcp;
> + req->p = calcp;
> + req->m = calcm - 1;
> +}
> +
> +/**
> +* sun8i_a83t_ahb1_recalc() - calculates AHB clock rate from m, p factors and
> +* parent index
> +*/
> +static void sun8i_a83t_ahb1_recalc(struct factors_request *req)
> +{
> + req->rate = req->parent_rate;
> +
> +/* apply pre-divider first if parent is pll6 */
The comment indentation is wrong
> + if (req->parent_index >= SUN6I_AHB1_PARENT_PLL6)
And this is not the right define you're using.
I still believe that duplicating the same logic just because of
different dividers is not the way to go.
You could solve that easily by adding a table for the muxes, and
associate it with parents and dividers, that you could store in
clk_factors.
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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