Re: [PATCH v2 1/5] clk: Ingenic: Adjust cgu code to make it compatible with X1830.

[Paul Cercueil <paul@crapouillou.net>]

Hi Zhou,


Le ven., déc. 13, 2019 at 23:21, 周琰杰 (Zhou Yanjie) 
<zhouyanjie@wanyeetech.com> a écrit :
> The PLL of X1830 Soc from Ingenic has been greatly changed,
> the bypass control is placed in another register, so now two
> registers may needed to control the PLL. To this end, the
> original "reg" was changed to "pll_reg", and a new "bypass_reg"
> was introduced. In addition, when calculating rate, the PLL of
> X1830 introduced an extra 2x multiplier, so a new "rate_multiplier"
> was introduced.
> 
> Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
> ---
> 
> Notes:
>     v1->v2:
>     1.Use two fields (pll_reg & bypass_reg) instead of the 2-values
>       array (reg[2]).
>     2.Remove the "pll_info->version" and add a 
> "pll_info->rate_multiplier".
>     3.Fix the coding style and add more detailed commit message.
>     4.Change my Signed-off-by from "Zhou Yanjie <zhouyanjie@zoho.com>"
>       to "周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>" because
>       the old mailbox is in an unstable state.
> 
>  drivers/clk/ingenic/cgu.c | 32 +++++++++++++++++++++-----------
>  drivers/clk/ingenic/cgu.h |  8 ++++++--
>  2 files changed, 27 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/clk/ingenic/cgu.c b/drivers/clk/ingenic/cgu.c
> index 6e96303..ae1ddcb 100644
> --- a/drivers/clk/ingenic/cgu.c
> +++ b/drivers/clk/ingenic/cgu.c
> @@ -84,7 +84,7 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned 
> long parent_rate)
>  	pll_info = &clk_info->pll;
> 
>  	spin_lock_irqsave(&cgu->lock, flags);
> -	ctl = readl(cgu->base + pll_info->reg);
> +	ctl = readl(cgu->base + pll_info->pll_reg);
>  	spin_unlock_irqrestore(&cgu->lock, flags);
> 
>  	m = (ctl >> pll_info->m_shift) & GENMASK(pll_info->m_bits - 1, 0);
> @@ -93,6 +93,11 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, 
> unsigned long parent_rate)
>  	n += pll_info->n_offset;
>  	od_enc = ctl >> pll_info->od_shift;
>  	od_enc &= GENMASK(pll_info->od_bits - 1, 0);
> +
> +	spin_lock_irqsave(&cgu->lock, flags);
> +	ctl = readl(cgu->base + pll_info->bypass_reg);
> +	spin_unlock_irqrestore(&cgu->lock, flags);

I think you should start the patchset with the current [5/5] patch; 
then you wouldn't have to add spinlock protection here just to see it 
removed later in the same patchset.

Cheers,
-Paul

> +
>  	bypass = !pll_info->no_bypass_bit &&
>  		 !!(ctl & BIT(pll_info->bypass_bit));
> 
> @@ -106,7 +111,7 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, 
> unsigned long parent_rate)
>  	BUG_ON(od == pll_info->od_max);
>  	od++;
> 
> -	return div_u64((u64)parent_rate * m, n * od);
> +	return div_u64((u64)parent_rate * m * pll_info->rate_multiplier, n 
> * od);
>  }
> 
>  static unsigned long
> @@ -139,7 +144,7 @@ ingenic_pll_calc(const struct 
> ingenic_cgu_clk_info *clk_info,
>  	if (pod)
>  		*pod = od;
> 
> -	return div_u64((u64)parent_rate * m, n * od);
> +	return div_u64((u64)parent_rate * m * pll_info->rate_multiplier, n 
> * od);
>  }
> 
>  static inline const struct ingenic_cgu_clk_info *to_clk_info(
> @@ -183,7 +188,7 @@ ingenic_pll_set_rate(struct clk_hw *hw, unsigned 
> long req_rate,
>  			clk_info->name, req_rate, rate);
> 
>  	spin_lock_irqsave(&cgu->lock, flags);
> -	ctl = readl(cgu->base + pll_info->reg);
> +	ctl = readl(cgu->base + pll_info->pll_reg);
> 
>  	ctl &= ~(GENMASK(pll_info->m_bits - 1, 0) << pll_info->m_shift);
>  	ctl |= (m - pll_info->m_offset) << pll_info->m_shift;
> @@ -194,7 +199,7 @@ ingenic_pll_set_rate(struct clk_hw *hw, unsigned 
> long req_rate,
>  	ctl &= ~(GENMASK(pll_info->od_bits - 1, 0) << pll_info->od_shift);
>  	ctl |= pll_info->od_encoding[od - 1] << pll_info->od_shift;
> 
> -	writel(ctl, cgu->base + pll_info->reg);
> +	writel(ctl, cgu->base + pll_info->pll_reg);
>  	spin_unlock_irqrestore(&cgu->lock, flags);
> 
>  	return 0;
> @@ -212,16 +217,21 @@ static int ingenic_pll_enable(struct clk_hw *hw)
>  	u32 ctl;
> 
>  	spin_lock_irqsave(&cgu->lock, flags);
> -	ctl = readl(cgu->base + pll_info->reg);
> +	ctl = readl(cgu->base + pll_info->bypass_reg);
> 
>  	ctl &= ~BIT(pll_info->bypass_bit);
> +
> +	writel(ctl, cgu->base + pll_info->bypass_reg);
> +
> +	ctl = readl(cgu->base + pll_info->pll_reg);
> +
>  	ctl |= BIT(pll_info->enable_bit);
> 
> -	writel(ctl, cgu->base + pll_info->reg);
> +	writel(ctl, cgu->base + pll_info->pll_reg);
> 
>  	/* wait for the PLL to stabilise */
>  	for (i = 0; i < timeout; i++) {
> -		ctl = readl(cgu->base + pll_info->reg);
> +		ctl = readl(cgu->base + pll_info->pll_reg);
>  		if (ctl & BIT(pll_info->stable_bit))
>  			break;
>  		mdelay(1);
> @@ -245,11 +255,11 @@ static void ingenic_pll_disable(struct clk_hw 
> *hw)
>  	u32 ctl;
> 
>  	spin_lock_irqsave(&cgu->lock, flags);
> -	ctl = readl(cgu->base + pll_info->reg);
> +	ctl = readl(cgu->base + pll_info->pll_reg);
> 
>  	ctl &= ~BIT(pll_info->enable_bit);
> 
> -	writel(ctl, cgu->base + pll_info->reg);
> +	writel(ctl, cgu->base + pll_info->pll_reg);
>  	spin_unlock_irqrestore(&cgu->lock, flags);
>  }
> 
> @@ -263,7 +273,7 @@ static int ingenic_pll_is_enabled(struct clk_hw 
> *hw)
>  	u32 ctl;
> 
>  	spin_lock_irqsave(&cgu->lock, flags);
> -	ctl = readl(cgu->base + pll_info->reg);
> +	ctl = readl(cgu->base + pll_info->pll_reg);
>  	spin_unlock_irqrestore(&cgu->lock, flags);
> 
>  	return !!(ctl & BIT(pll_info->enable_bit));
> diff --git a/drivers/clk/ingenic/cgu.h b/drivers/clk/ingenic/cgu.h
> index 0dc8004..f7b6908 100644
> --- a/drivers/clk/ingenic/cgu.h
> +++ b/drivers/clk/ingenic/cgu.h
> @@ -16,7 +16,9 @@
> 
>  /**
>   * struct ingenic_cgu_pll_info - information about a PLL
> - * @reg: the offset of the PLL's control register within the CGU
> + * @pll_reg: the offset of the PLL's control register within the CGU
> + * @bypass_reg: the offset of the bypass control register within the 
> CGU
> + * @rate_multiplier: the multiplier needed by pll rate calculation
>   * @m_shift: the number of bits to shift the multiplier value by 
> (ie. the
>   *           index of the lowest bit of the multiplier value in the 
> PLL's
>   *           control register)
> @@ -43,7 +45,9 @@
>   * @no_bypass_bit: if set, the PLL has no bypass functionality
>   */
>  struct ingenic_cgu_pll_info {
> -	unsigned reg;
> +	unsigned pll_reg;
> +	unsigned bypass_reg;
> +	unsigned rate_multiplier;
>  	const s8 *od_encoding;
>  	u8 m_shift, m_bits, m_offset;
>  	u8 n_shift, n_bits, n_offset;
> --
> 2.7.4
>