On Thu, 2018-08-09 at 15:07 +0800, Yixun Lan wrote:
> Export the emmc sub clock phase delay ops which will be used
> by the emmc sub clock driver itself.
> 
> Signed-off-by: Yixun Lan <yixun....@amlogic.com>
> ---
>  drivers/clk/meson/Makefile          |  2 +-
>  drivers/clk/meson/clk-phase-delay.c | 96 +++++++++++++++++++++++++++++
>  drivers/clk/meson/clkc.h            | 13 ++++
>  3 files changed, 110 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/clk/meson/clk-phase-delay.c
> 
> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
> index 72ec8c40d848..39ce5661b654 100644
> --- a/drivers/clk/meson/Makefile
> +++ b/drivers/clk/meson/Makefile
> @@ -2,7 +2,7 @@
>  # Makefile for Meson specific clk
>  #
>  
> -obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o
> +obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o 
> clk-phase-delay.o
>  obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO)       += clk-triphase.o sclk-div.o
>  obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o
>  obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
> diff --git a/drivers/clk/meson/clk-phase-delay.c 
> b/drivers/clk/meson/clk-phase-delay.c
> new file mode 100644
> index 000000000000..6f226814cfec
> --- /dev/null
> +++ b/drivers/clk/meson/clk-phase-delay.c
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Amlogic Meson MMC Sub Clock Controller Driver
> + *
> + * Copyright (c) 2017 Baylibre SAS.
> + * Author: Jerome Brunet <jbru...@baylibre.com>
> + *
> + * Copyright (c) 2018 Amlogic, inc.
> + * Author: Yixun Lan <yixun....@amlogic.com>
> + */
> +
> +#include <linux/clk-provider.h>
> +#include "clkc.h"
> +
> +#define SD_EMMC_CLOCK                        0

Drop this and use struct parm please.

> +
> +static int meson_clk_phase_delay_get_phase(struct clk_hw *hw)
> +{
> +     struct clk_regmap *clk = to_clk_regmap(hw);
> +     struct meson_clk_phase_delay_data *ph =
> +             meson_clk_get_phase_delay_data(clk);
> +     unsigned int phase_num = 1 <<  hweight_long(ph->phase_mask);
> +     unsigned long period_ps, p, d;
> +     int degrees;
> +     u32 val;
> +
> +     regmap_read(clk->map, SD_EMMC_CLOCK, &val);
> +     p = (val & ph->phase_mask) >> __ffs(ph->phase_mask);
> +     degrees = p * 360 / phase_num;
> +
> +     if (ph->delay_mask) {
> +             period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
> +                                      clk_hw_get_rate(hw));
> +             d = (val & ph->delay_mask) >> __ffs(ph->delay_mask);
> +             degrees += d * ph->delay_step_ps * 360 / period_ps;
> +             degrees %= 360;
> +     }
> +
> +     return degrees;
> +}
> +
> +static void meson_clk_apply_phase_delay(struct clk_regmap *clk,
> +                                     unsigned int phase,
> +                                     unsigned int delay)
> +{
> +     struct meson_clk_phase_delay_data *ph = clk->data;
> +     u32 val;
> +
> +     regmap_read(clk->map, SD_EMMC_CLOCK, &val);
> +
> +     val &= ~ph->phase_mask;
> +     val |= phase << __ffs(ph->phase_mask);
> +
> +     if (ph->delay_mask) {

This imply that delay is delay is optional. In such case, it would be a regular
"phase" and we already have a  driver for this. Please remove all the related
code and make this parameter required for this clock type.

In the future, maybe we'll merge the 2 drivers.

> +             val &= ~ph->delay_mask;
> +             val |= delay << __ffs(ph->delay_mask);
> +     }
> +
> +     regmap_write(clk->map, SD_EMMC_CLOCK, val);
> +}
> +
> +static int meson_clk_phase_delay_set_phase(struct clk_hw *hw, int degrees)
> +{
> +     struct clk_regmap *clk = to_clk_regmap(hw);
> +     struct meson_clk_phase_delay_data *ph =
> +             meson_clk_get_phase_delay_data(clk);
> +     unsigned int phase_num = 1 <<  hweight_long(ph->phase_mask);
> +     unsigned long period_ps, d = 0, r;
> +     u64 p;
> +
> +     p = degrees % 360;
> +
> +     if (!ph->delay_mask) {
> +             p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
> +     } else {
> +             period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
> +                                      clk_hw_get_rate(hw));
> +
> +             /* First compute the phase index (p), the remainder (r) is the
> +              * part we'll try to acheive using the delays (d).
> +              */
> +             r = do_div(p, 360 / phase_num);
> +             d = DIV_ROUND_CLOSEST(r * period_ps,
> +                                   360 * ph->delay_step_ps);
> +             d = min(d, ph->delay_mask >> __ffs(ph->delay_mask));
> +     }
> +
> +     meson_clk_apply_phase_delay(clk, p, d);
> +     return 0;
> +}
> +
> +const struct clk_ops meson_clk_phase_delay_ops = {
> +     .get_phase = meson_clk_phase_delay_get_phase,
> +     .set_phase = meson_clk_phase_delay_set_phase,
> +};
> +EXPORT_SYMBOL_GPL(meson_clk_phase_delay_ops);
> diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
> index 24cec16b6038..499834dd34f2 100644
> --- a/drivers/clk/meson/clkc.h
> +++ b/drivers/clk/meson/clkc.h
> @@ -113,6 +113,18 @@ struct clk_regmap _name = {                              
>                 \
>       },                                                              \
>  };
>  
> +struct meson_clk_phase_delay_data {
> +     unsigned long                   phase_mask;
> +     unsigned long                   delay_mask;

Like every other clock drivers in the amlogic directory, please use struct parm
to decribe the fields.

> +     unsigned int                    delay_step_ps;
> +};
> +
> +static inline struct meson_clk_phase_delay_data *
> +meson_clk_get_phase_delay_data(struct clk_regmap *clk)
> +{
> +     return (struct meson_clk_phase_delay_data *)clk->data;
> +}
> +
>  /* clk_ops */
>  extern const struct clk_ops meson_clk_pll_ro_ops;
>  extern const struct clk_ops meson_clk_pll_ops;
> @@ -120,5 +132,6 @@ extern const struct clk_ops meson_clk_cpu_ops;
>  extern const struct clk_ops meson_clk_mpll_ro_ops;
>  extern const struct clk_ops meson_clk_mpll_ops;
>  extern const struct clk_ops meson_clk_phase_ops;
> +extern const struct clk_ops meson_clk_phase_delay_ops;
>  
>  #endif /* __CLKC_H */


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