[PATCH v3 4/6] clk: samsung: Add set_rate() clk_ops for PLL36xx

Vikas Sajjan sajjan.linux at gmail.com
Wed Jun 12 02:09:30 EDT 2013


Hi Tomasz,

On Sat, Jun 8, 2013 at 5:47 PM, Tomasz Figa <tomasz.figa at gmail.com> wrote:
> On Friday 31 of May 2013 18:01:34 Vikas Sajjan wrote:
>> This patch adds set_rate and round_rate clk_ops for PLL36xx
>>
>> Reviewed-by: Doug Anderson <dianders at chromium.org>
>> Signed-off-by: Vikas Sajjan <vikas.sajjan at linaro.org>
>> ---
>>  drivers/clk/samsung/clk-pll.c |   59
>> +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59
>> insertions(+)
>>
>> diff --git a/drivers/clk/samsung/clk-pll.c
>> b/drivers/clk/samsung/clk-pll.c index 9591560..7143ed89 100644
>> --- a/drivers/clk/samsung/clk-pll.c
>> +++ b/drivers/clk/samsung/clk-pll.c
>> @@ -210,6 +210,9 @@ 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)
>> @@ -217,6 +220,8 @@ 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)
>> @@ -239,8 +244,57 @@ static unsigned long
>> samsung_pll36xx_recalc_rate(struct clk_hw *hw, return (unsigned
>> long)fvco;
>>  }
>>
>> +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);
>
> Hmm, PLL35xx has a fast path when only the S divisor changes. I'm not sure
> about any technical differences between these two PLLs (other than having
> the extra K factor and some more tunnables), but maybe it is possible for
> this one as well?


Sure, will check and respin once tested.
Yadwinder will respin the next version of this patch series , as i am
off this week.


>
> Otherwise looks fine.
>
> Reviewed-by: Tomasz Figa <t.figa at samsung.com>

Thanks.


>
>> +
>> +     /* 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,
>> @@ -264,6 +318,11 @@ struct clk * __init
>> samsung_clk_register_pll36xx(const char *name, init.parent_names =
>> &pname;
>>       init.num_parents = 1;
>>
>> +     if (rate_table && rate_count)
>> +             init.ops = &samsung_pll36xx_clk_ops;
>> +     else
>> +             init.ops = &samsung_pll36xx_clk_min_ops;
>> +
>>       pll->hw.init = &init;
>>       pll->base = base;
>>       pll->rate_table = rate_table;
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



More information about the linux-arm-kernel mailing list