[PATCH RFC 2/8] clk: sunxi-ng: sdm: Add dual patterns support

[Chen-Yu Tsai]

On Tue, Mar 10, 2026 at 4:42 PM Junhui Liu <junhui.liu at pigmoral.tech> wrote:
>
> On newer Allwinner platforms like the A733, the Sigma-Delta Modulation
> (SDM) control logic is more complex. The SDM enable bit, which was
> previously located in the PLL register, is now moved to a second
> pattern register (PATTERN1).
>
> To support this, rename the existing "tuning" members to "pattern0" to
> align with the datasheet, and introduce the _SUNXI_CCU_SDM_DUAL_PAT
> macro to provide pattern1 register support. Related operations are also
> updated.
>
> Signed-off-by: Junhui Liu <junhui.liu at pigmoral.tech>
> ---
>  drivers/clk/sunxi-ng/ccu_sdm.c | 51 +++++++++++++++++++++++++++++-------------
>  drivers/clk/sunxi-ng/ccu_sdm.h | 32 +++++++++++++++++---------
>  2 files changed, 57 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/clk/sunxi-ng/ccu_sdm.c b/drivers/clk/sunxi-ng/ccu_sdm.c
> index c564e5f9e610..204e25feaa36 100644
> --- a/drivers/clk/sunxi-ng/ccu_sdm.c
> +++ b/drivers/clk/sunxi-ng/ccu_sdm.c
> @@ -18,7 +18,10 @@ bool ccu_sdm_helper_is_enabled(struct ccu_common *common,
>         if (sdm->enable && !(readl(common->base + common->reg) & sdm->enable))
>                 return false;
>
> -       return !!(readl(common->base + sdm->tuning_reg) & sdm->tuning_enable);
> +       if (sdm->pat1_enable && !(readl(common->base + sdm->pat1_reg) & sdm->pat1_enable))
> +               return false;
> +
> +       return !!(readl(common->base + sdm->pat0_reg) & sdm->pat0_enable);
>  }
>  EXPORT_SYMBOL_NS_GPL(ccu_sdm_helper_is_enabled, "SUNXI_CCU");
>
> @@ -37,18 +40,27 @@ void ccu_sdm_helper_enable(struct ccu_common *common,
>         for (i = 0; i < sdm->table_size; i++)
>                 if (sdm->table[i].rate == rate)
>                         writel(sdm->table[i].pattern,
> -                              common->base + sdm->tuning_reg);
> +                              common->base + sdm->pat0_reg);
>
>         /* Make sure SDM is enabled */
>         spin_lock_irqsave(common->lock, flags);
> -       reg = readl(common->base + sdm->tuning_reg);
> -       writel(reg | sdm->tuning_enable, common->base + sdm->tuning_reg);
> +       reg = readl(common->base + sdm->pat0_reg);
> +       writel(reg | sdm->pat0_enable, common->base + sdm->pat0_reg);
>         spin_unlock_irqrestore(common->lock, flags);
>
> -       spin_lock_irqsave(common->lock, flags);
> -       reg = readl(common->base + common->reg);
> -       writel(reg | sdm->enable, common->base + common->reg);
> -       spin_unlock_irqrestore(common->lock, flags);
> +       if (sdm->enable) {
> +               spin_lock_irqsave(common->lock, flags);
> +               reg = readl(common->base + common->reg);
> +               writel(reg | sdm->enable, common->base + common->reg);
> +               spin_unlock_irqrestore(common->lock, flags);
> +       }
> +
> +       if (sdm->pat1_enable) {
> +               spin_lock_irqsave(common->lock, flags);
> +               reg = readl(common->base + sdm->pat1_reg);
> +               writel(reg | sdm->pat1_enable, common->base + sdm->pat1_reg);
> +               spin_unlock_irqrestore(common->lock, flags);
> +       }
>  }
>  EXPORT_SYMBOL_NS_GPL(ccu_sdm_helper_enable, "SUNXI_CCU");
>
> @@ -61,14 +73,23 @@ void ccu_sdm_helper_disable(struct ccu_common *common,
>         if (!(common->features & CCU_FEATURE_SIGMA_DELTA_MOD))
>                 return;
>
> -       spin_lock_irqsave(common->lock, flags);
> -       reg = readl(common->base + common->reg);
> -       writel(reg & ~sdm->enable, common->base + common->reg);
> -       spin_unlock_irqrestore(common->lock, flags);
> +       if (sdm->enable) {
> +               spin_lock_irqsave(common->lock, flags);
> +               reg = readl(common->base + common->reg);
> +               writel(reg & ~sdm->enable, common->base + common->reg);
> +               spin_unlock_irqrestore(common->lock, flags);
> +       }
> +
> +       if (sdm->pat1_enable) {
> +               spin_lock_irqsave(common->lock, flags);
> +               reg = readl(common->base + sdm->pat1_reg);
> +               writel(reg & ~sdm->pat1_enable, common->base + sdm->pat1_reg);
> +               spin_unlock_irqrestore(common->lock, flags);
> +       }
>
>         spin_lock_irqsave(common->lock, flags);
> -       reg = readl(common->base + sdm->tuning_reg);
> -       writel(reg & ~sdm->tuning_enable, common->base + sdm->tuning_reg);
> +       reg = readl(common->base + sdm->pat0_reg);
> +       writel(reg & ~sdm->pat0_enable, common->base + sdm->pat0_reg);
>         spin_unlock_irqrestore(common->lock, flags);
>  }
>  EXPORT_SYMBOL_NS_GPL(ccu_sdm_helper_disable, "SUNXI_CCU");
> @@ -123,7 +144,7 @@ unsigned long ccu_sdm_helper_read_rate(struct ccu_common *common,
>         pr_debug("%s: clock is sigma-delta modulated\n",
>                  clk_hw_get_name(&common->hw));
>
> -       reg = readl(common->base + sdm->tuning_reg);
> +       reg = readl(common->base + sdm->pat0_reg);
>
>         pr_debug("%s: pattern reg is 0x%x",
>                  clk_hw_get_name(&common->hw), reg);
> diff --git a/drivers/clk/sunxi-ng/ccu_sdm.h b/drivers/clk/sunxi-ng/ccu_sdm.h
> index c1a7159b89c3..c289be28e1b4 100644
> --- a/drivers/clk/sunxi-ng/ccu_sdm.h
> +++ b/drivers/clk/sunxi-ng/ccu_sdm.h
> @@ -33,21 +33,31 @@ struct ccu_sdm_internal {
>         u32             table_size;
>         /* early SoCs don't have the SDM enable bit in the PLL register */
>         u32             enable;
> -       /* second enable bit in tuning register */
> -       u32             tuning_enable;
> -       u16             tuning_reg;
> +       /* second enable bit in pattern0 register */
> +       u32             pat0_enable;
> +       u16             pat0_reg;
> +       /* on some platforms, the sdm enable bit in pattern1 register */
> +       u32             pat1_enable;
> +       u16             pat1_reg;
>  };
>
> -#define _SUNXI_CCU_SDM(_table, _enable,                        \
> -                      _reg, _reg_enable)               \
> -       {                                               \
> -               .table          = _table,               \
> -               .table_size     = ARRAY_SIZE(_table),   \
> -               .enable         = _enable,              \
> -               .tuning_enable  = _reg_enable,          \
> -               .tuning_reg     = _reg,                 \
> +#define __SUNXI_CCU_SDM(_table, _enable, _pat0, _pat0_enable, _pat1, _pat1_enable)     \
> +       {                                                               \
> +               .table                  = _table,                       \
> +               .table_size             = ARRAY_SIZE(_table),           \
> +               .enable                 = _enable,                      \
> +               .pat0_enable            = _pat0_enable,                 \
> +               .pat0_reg               = _pat0,                        \
> +               .pat1_enable            = _pat1_enable,                 \
> +               .pat1_reg               = _pat1,                        \
>         }
>
> +#define _SUNXI_CCU_SDM(_table, _enable, _pat0, _pat0_enable)   \
> +       __SUNXI_CCU_SDM(_table, _enable, _pat0, _pat0_enable, 0, 0)
> +
> +#define _SUNXI_CCU_SDM_DUAL_PAT(_table, _pat0, _pat0_enable, _pat1, _pat1_enable)      \
> +       __SUNXI_CCU_SDM(_table, 0, _pat0, _pat0_enable, _pat1, _pat1_enable)
> +

Don't introduce an intermediate macro that looks _almost_ the same as the
macro the driver is actually supposed to use.

Just declare _SUNXI_CCU_SDM_DUAL_PAT() to expand to the full entry, and
_SUNXI_CCU_SDM() to _SUNXI_CCU_SDM_DUAL_PAT() with the last two parameters
as zero. That takes less lines.


ChenYu

>  bool ccu_sdm_helper_is_enabled(struct ccu_common *common,
>                                struct ccu_sdm_internal *sdm);
>  void ccu_sdm_helper_enable(struct ccu_common *common,
>
> --
> 2.52.0
>
>