[PATCH 1/4] clk: sunxi: Rework MMC phase clocks

Chen-Yu Tsai wens at csie.org
Mon Dec 8 08:53:35 PST 2014


On Mon, Dec 8, 2014 at 1:21 AM, Maxime Ripard
<maxime.ripard at free-electrons.com> wrote:
> Instead of having three different clocks for the main MMC clock and the two
> phase sub-clocks, which involved having three different drivers sharing the
> same register, rework it to have the same single driver registering three
> different clocks.
>
> Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
> ---
>  drivers/clk/sunxi/clk-mod0.c | 129 ++++++++++++++++++++++---------------------
>  1 file changed, 67 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
> index 658d74f39451..24522c5b94ae 100644
> --- a/drivers/clk/sunxi/clk-mod0.c
> +++ b/drivers/clk/sunxi/clk-mod0.c
> @@ -115,19 +115,17 @@ static void __init sun5i_a13_mbus_setup(struct device_node *node)
>  }
>  CLK_OF_DECLARE(sun5i_a13_mbus, "allwinner,sun5i-a13-mbus-clk", sun5i_a13_mbus_setup);
>
> -struct mmc_phase_data {
> -       u8      offset;
> -};
> -
>  struct mmc_phase {
>         struct clk_hw           hw;
> +       u8                      offset;
>         void __iomem            *reg;
> -       struct mmc_phase_data   *data;
>         spinlock_t              *lock;
>  };
>
>  #define to_mmc_phase(_hw) container_of(_hw, struct mmc_phase, hw)
>
> +static DEFINE_SPINLOCK(sun4i_a10_mmc_lock);
> +

I'd move this to just above the setup function.
The get/set_phase callbacks don't need it.

>  static int mmc_get_phase(struct clk_hw *hw)
>  {
>         struct clk *mmc, *mmc_parent, *clk = hw->clk;
> @@ -138,7 +136,7 @@ static int mmc_get_phase(struct clk_hw *hw)
>         u8 delay;
>
>         value = readl(phase->reg);
> -       delay = (value >> phase->data->offset) & 0x3;
> +       delay = (value >> phase->offset) & 0x3;
>
>         if (!delay)
>                 return 180;
> @@ -226,8 +224,8 @@ static int mmc_set_phase(struct clk_hw *hw, int degrees)
>
>         spin_lock_irqsave(phase->lock, flags);
>         value = readl(phase->reg);
> -       value &= ~GENMASK(phase->data->offset + 3, phase->data->offset);
> -       value |= delay << phase->data->offset;
> +       value &= ~GENMASK(phase->offset + 3, phase->offset);
> +       value |= delay << phase->offset;
>         writel(value, phase->reg);
>         spin_unlock_irqrestore(phase->lock, flags);
>
> @@ -239,66 +237,73 @@ static const struct clk_ops mmc_clk_ops = {
>         .set_phase      = mmc_set_phase,
>  };
>
> -static void __init sun4i_a10_mmc_phase_setup(struct device_node *node,
> -                                            struct mmc_phase_data *data)
> +static void __init sun4i_a10_mmc_setup(struct device_node *node)
>  {
> -       const char *parent_names[1] = { of_clk_get_parent_name(node, 0) };
> -       struct clk_init_data init = {
> -               .num_parents    = 1,
> -               .parent_names   = parent_names,
> -               .ops            = &mmc_clk_ops,
> -       };
> -
> -       struct mmc_phase *phase;
> -       struct clk *clk;
> -
> -       phase = kmalloc(sizeof(*phase), GFP_KERNEL);
> -       if (!phase)
> -               return;
> -
> -       phase->hw.init = &init;
> -
> -       phase->reg = of_iomap(node, 0);
> -       if (!phase->reg)
> -               goto err_free;
> +       struct clk_onecell_data *clk_data;
> +       const char *parent;
> +       void __iomem *reg;
> +       int i;
>
> -       phase->data = data;
> -       phase->lock = &sun4i_a10_mod0_lock;
> +       reg = of_io_request_and_map(node, 0, of_node_full_name(node));
> +       if (IS_ERR(reg)) {
> +               pr_err("Couldn't map the %s clock registers\n", node->name);
> +               return;
> +       }
>
> -       if (of_property_read_string(node, "clock-output-names", &init.name))
> -               init.name = node->name;
> +       clk_data = kmalloc(sizeof(*clk_data), GFP_KERNEL);
> +       if (!clk_data)
> +               return;
>
> -       clk = clk_register(NULL, &phase->hw);
> -       if (IS_ERR(clk))
> -               goto err_unmap;
> +       clk_data->clks = kcalloc(3, sizeof(*clk_data->clks), GFP_KERNEL);
> +       if (!clk_data->clks)
> +               goto err_free_data;
> +
> +       clk_data->clk_num = 3;
> +       clk_data->clks[0] = sunxi_factors_register(node,
> +                                                  &sun4i_a10_mod0_data,
> +                                                  &sun4i_a10_mmc_lock, reg);
> +       if (!clk_data->clks[0])
> +               goto err_free_clks;
> +
> +       parent = __clk_get_name(clk_data->clks[0]);
> +
> +       for (i = 1; i < 3; i++) {
> +               struct clk_init_data init = {
> +                       .num_parents    = 1,
> +                       .parent_names   = &parent,
> +                       .ops            = &mmc_clk_ops,
> +               };
> +               struct mmc_phase *phase;
> +
> +               phase = kmalloc(sizeof(*phase), GFP_KERNEL);
> +               if (!phase)
> +                       continue;
> +
> +               phase->hw.init = &init;
> +               phase->reg = reg;
> +               phase->lock = &sun4i_a10_mmc_lock;
> +
> +               if (i == 1)
> +                       phase->offset = 8;
> +               else
> +                       phase->offset = 20;
> +
> +               if (of_property_read_string_index(node, "clock-output-names",
> +                                                 i, &init.name))
> +                       init.name = node->name;

You could assign first, then call of_property_read_string_index.
It won't touch the string unless a valid string is found.

> +
> +               clk_data->clks[i] = clk_register(NULL, &phase->hw);
> +               if (IS_ERR(clk_data->clks[i]))
> +                       continue;

I'm a bit skeptical about partial success/failure, though I don't
have a strong argument for or against it yet.

ChenYu

> +       }
>
> -       of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +       of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
>
>         return;
>
> -err_unmap:
> -       iounmap(phase->reg);
> -err_free:
> -       kfree(phase);
> -}
> -
> -
> -static struct mmc_phase_data mmc_output_clk = {
> -       .offset = 8,
> -};
> -
> -static struct mmc_phase_data mmc_sample_clk = {
> -       .offset = 20,
> -};
> -
> -static void __init sun4i_a10_mmc_output_setup(struct device_node *node)
> -{
> -       sun4i_a10_mmc_phase_setup(node, &mmc_output_clk);
> -}
> -CLK_OF_DECLARE(sun4i_a10_mmc_output, "allwinner,sun4i-a10-mmc-output-clk", sun4i_a10_mmc_output_setup);
> -
> -static void __init sun4i_a10_mmc_sample_setup(struct device_node *node)
> -{
> -       sun4i_a10_mmc_phase_setup(node, &mmc_sample_clk);
> +err_free_clks:
> +       kfree(clk_data->clks);
> +err_free_data:
> +       kfree(clk_data);
>  }
> -CLK_OF_DECLARE(sun4i_a10_mmc_sample, "allwinner,sun4i-a10-mmc-sample-clk", sun4i_a10_mmc_sample_setup);
> +CLK_OF_DECLARE(sun4i_a10_mmc, "allwinner,sun4i-a10-mmc-clk", sun4i_a10_mmc_setup);
> --
> 2.2.0



More information about the linux-arm-kernel mailing list