Re: [PATCH v6 4/7] clk: samsung: Add set_rate() clk_ops for PLL35xx

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

On Monday 10 of June 2013 18:54:16 Yadwinder Singh Brar wrote:
> This patch add set_rate() and round_rate() for PLL35xx
> 
> Reviewed-by: Doug Anderson <dianders@chromium.org>
> Reviewed-by: Tomasz Figa <t.figa@samsung.com>
> Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
> ---
>  drivers/clk/samsung/clk-pll.c |  105
> ++++++++++++++++++++++++++++++++++++++++- 1 files changed, 104
> insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/clk/samsung/clk-pll.c
> b/drivers/clk/samsung/clk-pll.c index b2088dd..e3e7f0c 100644
> --- a/drivers/clk/samsung/clk-pll.c
> +++ b/drivers/clk/samsung/clk-pll.c
> @@ -24,16 +24,51 @@ struct samsung_clk_pll {
> 
>  #define to_clk_pll(_hw) container_of(_hw, struct samsung_clk_pll, hw)
> 
> +static const struct samsung_pll_rate_table *samsung_get_pll_settings(
> +				struct samsung_clk_pll *pll, unsigned long 
rate)
> +{
> +	const struct samsung_pll_rate_table  *rate_table = pll-
>rate_table;
> +	int i;
> +
> +	for (i = 0; i < pll->rate_count; i++) {
> +		if (rate == rate_table[i].rate)
> +			return &rate_table[i];
> +	}
> +
> +	return NULL;
> +}
> +
> +static long samsung_pll_round_rate(struct clk_hw *hw,
> +			unsigned long drate, unsigned long *prate)
> +{
> +	struct samsung_clk_pll *pll = to_clk_pll(hw);
> +	const struct samsung_pll_rate_table *rate_table = pll->rate_table;
> +	int i;
> +
> +	/* Assumming rate_table is in descending order */
> +	for (i = 0; i < pll->rate_count; i++) {
> +		if (drate >= rate_table[i].rate)
> +			return rate_table[i].rate;
> +	}
> +
> +	/* return minimum supported value */
> +	return rate_table[i - 1].rate;
> +}
> +
>  /*
>   * PLL35xx Clock Type
>   */
> +/* Maximum lock time can be 270 * PDIV cycles */
> +#define PLL35XX_LOCK_FACTOR	(270)
> 
>  #define PLL35XX_MDIV_MASK       (0x3FF)
>  #define PLL35XX_PDIV_MASK       (0x3F)
>  #define PLL35XX_SDIV_MASK       (0x7)
> +#define PLL35XX_LOCK_STAT_MASK	(0x1)
>  #define PLL35XX_MDIV_SHIFT      (16)
>  #define PLL35XX_PDIV_SHIFT      (8)
>  #define PLL35XX_SDIV_SHIFT      (0)
> +#define PLL35XX_LOCK_STAT_SHIFT	(29)
> 
>  static unsigned long samsung_pll35xx_recalc_rate(struct clk_hw *hw,
>  				unsigned long parent_rate)
> @@ -53,8 +88,73 @@ static unsigned long
> samsung_pll35xx_recalc_rate(struct clk_hw *hw, return (unsigned
> long)fvco;
>  }
> 
> +static inline bool samsung_pll35xx_mp_change(
> +		const struct samsung_pll_rate_table *rate, u32 pll_con)
> +{
> +	u32 old_mdiv, old_pdiv;
> +
> +	old_mdiv = (pll_con >> PLL35XX_MDIV_SHIFT) & PLL35XX_MDIV_MASK;
> +	old_pdiv = (pll_con >> PLL35XX_PDIV_SHIFT) & PLL35XX_PDIV_MASK;
> +
> +	return (rate->mdiv != old_mdiv || rate->pdiv != old_pdiv);
> +}
> +
> +static int samsung_pll35xx_set_rate(struct clk_hw *hw, unsigned long
> drate, +					unsigned long prate)
> +{
> +	struct samsung_clk_pll *pll = to_clk_pll(hw);
> +	const struct samsung_pll_rate_table *rate;
> +	u32 tmp;
> +
> +	/* Get required rate settings from table */
> +	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;
> +	}
> +
> +	tmp = __raw_readl(pll->con_reg);
> +
> +	if (!(samsung_pll35xx_mp_change(rate, tmp))) {
> +		/* If only s change, change just s value only*/
> +		tmp &= ~(PLL35XX_SDIV_MASK << PLL35XX_SDIV_SHIFT);
> +		tmp |= rate->sdiv << PLL35XX_SDIV_SHIFT;
> +		__raw_writel(tmp, pll->con_reg);
> +
> +		return 0;
> +	}
> +
> +	/* Set PLL lock time. */
> +	__raw_writel(rate->pdiv * PLL35XX_LOCK_FACTOR,
> +			pll->lock_reg);
> +
> +	/* Change PLL PMS values */
> +	tmp &= ~((PLL35XX_MDIV_MASK << PLL35XX_MDIV_SHIFT) |
> +			(PLL35XX_PDIV_MASK << PLL35XX_PDIV_SHIFT) |
> +			(PLL35XX_SDIV_MASK << PLL35XX_SDIV_SHIFT));
> +	tmp |= (rate->mdiv << PLL35XX_MDIV_SHIFT) |
> +			(rate->pdiv << PLL35XX_PDIV_SHIFT) |
> +			(rate->sdiv << PLL35XX_SDIV_SHIFT);
> +	__raw_writel(tmp, pll->con_reg);
> +
> +	/* wait_lock_time */
> +	do {
> +		cpu_relax();
> +		tmp = __raw_readl(pll->con_reg);
> +	} while (!(tmp & (PLL35XX_LOCK_STAT_MASK
> +				<< PLL35XX_LOCK_STAT_SHIFT)));
> +	return 0;
> +}
> +
>  static const struct clk_ops samsung_pll35xx_clk_ops = {
>  	.recalc_rate = samsung_pll35xx_recalc_rate,
> +	.round_rate = samsung_pll_round_rate,
> +	.set_rate = samsung_pll35xx_set_rate,
> +};
> +
> +static const struct clk_ops samsung_pll35xx_clk_min_ops = {
> +	.recalc_rate = samsung_pll35xx_recalc_rate,
>  };
> 
>  /*
> @@ -386,7 +486,10 @@ void __init samsung_clk_register_pll(struct
> samsung_pll_clock *clk_list, /* clk_ops for 35xx and 2550 are similar
> */
>  		case pll_35xx:
>  		case pll_2550:
> -			init.ops = &samsung_pll35xx_clk_ops;
> +			if (!pll->rate_table)
> +				init.ops = &samsung_pll35xx_clk_min_ops;
> +			else
> +				init.ops = &samsung_pll35xx_clk_ops;
>  			break;
>  		/* clk_ops for 36xx and 2650 are similar */
>  		case pll_36xx:

Looks good.

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

Best regards,
Tomasz