Re: [PATCH v4 07/13] clk: microchip: mpfs: add MSS pll's set & round rate

From: Claudiu.Beznea
Date: Thu Sep 08 2022 - 02:46:33 EST


On 30.08.2022 15:52, Conor Dooley wrote:
> The MSS pll is not a fixed frequency clock, so add set() & round_rate()
> support.
> Control is limited to a 7 bit output divider as other devices on the
> FPGA occupy the other three outputs of the PLL & prevent changing
> the multiplier.
>
> Reviewed-by: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>

Reviewed-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>


> ---
> drivers/clk/microchip/clk-mpfs.c | 54 ++++++++++++++++++++++++++++++++
> 1 file changed, 54 insertions(+)
>
> diff --git a/drivers/clk/microchip/clk-mpfs.c b/drivers/clk/microchip/clk-mpfs.c
> index 43cc9583cd14..008b76d81485 100644
> --- a/drivers/clk/microchip/clk-mpfs.c
> +++ b/drivers/clk/microchip/clk-mpfs.c
> @@ -131,8 +131,62 @@ static unsigned long mpfs_clk_msspll_recalc_rate(struct clk_hw *hw, unsigned lon
> return prate * mult / (ref_div * MSSPLL_FIXED_DIV * postdiv);
> }
>
> +static long mpfs_clk_msspll_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate)
> +{
> + struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
> + void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
> + void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
> + u32 mult, ref_div;
> + unsigned long rate_before_ctrl;
> +
> + mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
> + mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
> + ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
> + ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
> +
> + rate_before_ctrl = rate * (ref_div * MSSPLL_FIXED_DIV) / mult;
> +
> + return divider_round_rate(hw, rate_before_ctrl, prate, NULL, MSSPLL_POSTDIV_WIDTH,
> + msspll_hw->flags);
> +}
> +
> +static int mpfs_clk_msspll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long prate)
> +{
> + struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
> + void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
> + void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
> + void __iomem *postdiv_addr = msspll_hw->base + REG_MSSPLL_POSTDIV_CR;
> + u32 mult, ref_div, postdiv;
> + int divider_setting;
> + unsigned long rate_before_ctrl, flags;
> +
> + mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
> + mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
> + ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
> + ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
> +
> + rate_before_ctrl = rate * (ref_div * MSSPLL_FIXED_DIV) / mult;
> + divider_setting = divider_get_val(rate_before_ctrl, prate, NULL, MSSPLL_POSTDIV_WIDTH,
> + msspll_hw->flags);
> +
> + if (divider_setting < 0)
> + return divider_setting;
> +
> + spin_lock_irqsave(&mpfs_clk_lock, flags);
> +
> + postdiv = readl_relaxed(postdiv_addr);
> + postdiv &= ~(clk_div_mask(MSSPLL_POSTDIV_WIDTH) << MSSPLL_POSTDIV_SHIFT);
> + writel_relaxed(postdiv, postdiv_addr);
> +
> + spin_unlock_irqrestore(&mpfs_clk_lock, flags);
> +
> + return 0;
> +}
> +
> static const struct clk_ops mpfs_clk_msspll_ops = {
> .recalc_rate = mpfs_clk_msspll_recalc_rate,
> + .round_rate = mpfs_clk_msspll_round_rate,
> + .set_rate = mpfs_clk_msspll_set_rate,
> };
>
> #define CLK_PLL(_id, _name, _parent, _shift, _width, _flags, _offset) { \