Re: [PATCH v4 4/6] clk: samsung: Add set_rate() clk_ops for PLL36xx

[Tomasz Figa <tomasz.figa@gmail.com>]

Hi Yadwinder, Vikas,

On Monday 03 of June 2013 20:39:54 Yadwinder Singh Brar wrote:
> From: Vikas Sajjan <vikas.sajjan@linaro.org>
> 
> This patch adds set_rate and round_rate clk_ops for PLL36xx
> 
> Reviewed-by: Tomasz Figa <t.figa@samsung.com>
> Reviewed-by: Doug Anderson <dianders@chromium.org>
> Signed-off-by: Vikas Sajjan <vikas.sajjan@linaro.org>
> ---
>  drivers/clk/samsung/clk-pll.c |   79
> ++++++++++++++++++++++++++++++++++++++++- 1 files changed, 78
> insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/clk/samsung/clk-pll.c
> b/drivers/clk/samsung/clk-pll.c index 319b52b..42b60b5 100644
> --- a/drivers/clk/samsung/clk-pll.c
> +++ b/drivers/clk/samsung/clk-pll.c
> @@ -215,6 +215,9 @@ struct clk * __init
> samsung_clk_register_pll35xx(const char *name, #define
> PLL36XX_CON0_OFFSET	(0x100)
>  #define PLL36XX_CON1_OFFSET	(0x104)
> 
> +/* Maximum lock time can be 3000 * PDIV cycles */
> +#define PLL36XX_LOCK_FACTOR	(3000)
> +
>  #define PLL36XX_KDIV_MASK	(0xFFFF)
>  #define PLL36XX_MDIV_MASK	(0x1FF)
>  #define PLL36XX_PDIV_MASK	(0x3F)
> @@ -222,6 +225,8 @@ struct clk * __init
> samsung_clk_register_pll35xx(const char *name, #define
> PLL36XX_MDIV_SHIFT	(16)
>  #define PLL36XX_PDIV_SHIFT	(8)
>  #define PLL36XX_SDIV_SHIFT	(0)
> +#define PLL36XX_KDIV_SHIFT	(0)
> +#define PLL36XX_LOCK_STAT_SHIFT	(29)
> 
>  static unsigned long samsung_pll36xx_recalc_rate(struct clk_hw *hw,
>  				unsigned long parent_rate)
> @@ -244,8 +249,78 @@ static unsigned long
> samsung_pll36xx_recalc_rate(struct clk_hw *hw, return (unsigned
> long)fvco;
>  }
> 
> +static inline bool samsung_pll36xx_mpk_change(
> +	const struct samsung_pll_rate_table *rate, u32 pll_con0, u32 
pll_con1)
> +{
> +	u32 old_mdiv, old_pdiv, old_kdiv;
> +
> +	old_mdiv = (pll_con0 >> PLL36XX_MDIV_SHIFT) & PLL36XX_MDIV_MASK;
> +	old_pdiv = (pll_con0 >> PLL36XX_PDIV_SHIFT) & PLL36XX_PDIV_MASK;
> +	old_kdiv = (pll_con1 >> PLL36XX_KDIV_SHIFT) & PLL36XX_KDIV_MASK;
> +
> +	return (rate->mdiv != old_mdiv || rate->pdiv != old_pdiv ||
> +		rate->kdiv != old_kdiv);
> +}
> +
> +static int samsung_pll36xx_set_rate(struct clk_hw *hw, unsigned long
> drate, +					unsigned long parent_rate)
> +{
> +	struct samsung_clk_pll *pll = to_clk_pll(hw);
> +	u32 tmp, pll_con0, pll_con1;
> +	const struct samsung_pll_rate_table *rate;
> +
> +	rate = samsung_get_pll_settings(pll, drate);
> +	if (!rate) {
> +		pr_err("%s: Invalid rate : %lu for pll clk %s\n", 
__func__,
> +			drate, __clk_get_name(hw->clk));
> +		return -EINVAL;
> +	}
> +
> +	pll_con0 = pll_readl(pll, PLL36XX_CON0_OFFSET);
> +	pll_con1 = pll_readl(pll, PLL36XX_CON1_OFFSET);
> +
> +	if (!(samsung_pll36xx_mpk_change(rate, pll_con0, pll_con1))) {
> +		/* If only s change, change just s value only*/
> +		pll_con0 &= ~(PLL36XX_SDIV_MASK << PLL36XX_SDIV_SHIFT);
> +		pll_con0 |= (rate->sdiv << PLL36XX_SDIV_SHIFT);
> +		pll_writel(pll, pll_con0, PLL36XX_CON0_OFFSET);

nit, I would put an empty line before the return statement here, to make 
it stand out a bit more.

Otherwise looks fine for me.

Reviewed-by: Tomasz Figa <t.figa@samsung.com>

Best regards,
Tomasz

> +		return 0;
> +	}
> +
> +	/* Set PLL lock time. */
> +	pll_writel(pll, (rate->pdiv * PLL36XX_LOCK_FACTOR),
> +			PLL36XX_LOCK_OFFSET);
> +
> +	 /* Change PLL PMS values */
> +	pll_con0 &= ~((PLL36XX_MDIV_MASK << PLL36XX_MDIV_SHIFT) |
> +			(PLL36XX_PDIV_MASK << PLL36XX_PDIV_SHIFT) |
> +			(PLL36XX_SDIV_MASK << PLL36XX_SDIV_SHIFT));
> +	pll_con0 |= (rate->mdiv << PLL36XX_MDIV_SHIFT) |
> +			(rate->pdiv << PLL36XX_PDIV_SHIFT) |
> +			(rate->sdiv << PLL36XX_SDIV_SHIFT);
> +	pll_writel(pll, pll_con0, PLL36XX_CON0_OFFSET);
> +
> +	pll_con1 &= ~(PLL36XX_KDIV_MASK << PLL36XX_KDIV_SHIFT);
> +	pll_con1 |= rate->kdiv << PLL36XX_KDIV_SHIFT;
> +	pll_writel(pll, pll_con1, PLL36XX_CON1_OFFSET);
> +
> +	/* wait_lock_time */
> +	do {
> +		cpu_relax();
> +		tmp = pll_readl(pll, PLL36XX_CON0_OFFSET);
> +	} while (!(tmp & (1 << PLL36XX_LOCK_STAT_SHIFT)));
> +
> +	return 0;
> +}
> +
>  static const struct clk_ops samsung_pll36xx_clk_ops = {
>  	.recalc_rate = samsung_pll36xx_recalc_rate,
> +	.set_rate = samsung_pll36xx_set_rate,
> +	.round_rate = samsung_pll_round_rate,
> +};
> +
> +static const struct clk_ops samsung_pll36xx_clk_min_ops = {
> +	.recalc_rate = samsung_pll36xx_recalc_rate,
>  };
> 
>  struct clk * __init samsung_clk_register_pll36xx(const char *name,
> @@ -264,7 +339,6 @@ struct clk * __init
> samsung_clk_register_pll36xx(const char *name, }
> 
>  	init.name = name;
> -	init.ops = &samsung_pll36xx_clk_ops;
>  	init.flags = CLK_GET_RATE_NOCACHE;
>  	init.parent_names = &pname;
>  	init.num_parents = 1;
> @@ -273,6 +347,9 @@ struct clk * __init
> samsung_clk_register_pll36xx(const char *name, pll->rate_count =
> rate_count;
>  		pll->rate_table = kmemdup(rate_table, rate_count *
>  			sizeof(struct samsung_pll_rate_table), 
GFP_KERNEL);
> +		init.ops = &samsung_pll36xx_clk_ops;
> +	} else {
> +		init.ops = &samsung_pll36xx_clk_min_ops;
>  	}
> 
>  	pll->hw.init = &init;