[PATCH v4 1/6] clk: samsung: Use clk->base instead of directly using clk->con0 for PLL3xxx

Yadwinder Singh Brar yadi.brar01 at gmail.com
Thu Jun 13 03:02:05 EDT 2013


On Thu, Jun 13, 2013 at 3:32 AM, Andrew Bresticker
<abrestic at chromium.org> wrote:
> Doug,
>
>>> Hmm, if done properly, it could simplify PLL registration in SoC clock
>>> initialization code a lot.
>>>
>>> I'm not sure if this is really the best solution (feel free to suggest
>>> anything better), but we could put PLLs in an array, like other clocks,
>>> e.g.
>>>
>>>         ... exynos4210_pll_clks[] = {
>>>                 CLK_PLL45XX(...),
>>>                 CLK_PLL45XX(...),
>>>                 CLK_PLL46XX(...),
>>>                 CLK_PLL46XX(...),
>>>         };
>>>
>>> and then just call a helper like
>>>
>>>         samsung_clk_register_pll(exynos4210_pll_clks,
>>>                         ARRAY_SIZE(exynos4210_pll_clks));
>>
>> Something like that looks like what I was thinking.  I'd have to see
>> it actually coded up to see if there's something I'm missing that
>> would prevent us from doing that, but I don't see anything.
>
> The only issue I see with this is that we may only want to register a
> rate table with a PLL only if fin_pll is running at a certain rate.
> On 5250 and 5420, for example, we have EPLL and VPLL rate tables that
> should only be registered if fin_pll is 24Mhz.  We may have to
> register those separately, but this approach seems fine otherwise.
>

As Andrew Bresticker said, we will face problem with different table,
and it will give some pain while handling such cases but I think
overall code may look better.

Similar thoughts were their in my mind also, but i didn't want to
disturb this series :).
Anyways, I think we can do it now only rather going for incremental
patches after this series.
I was thinking to make samsung_clk_register_pllxxxx itself  little
generic instead
of using helper, as we are almost duplicating code for most PLLs.

A rough picture in my mind was,
After implementing  generic samung_clk_register_pll(), code may look like
below. Its just an idea, please feel free to correct it.
Later we can factor out other common clk.ops for PLLs also.

this diff is over this series.
Assuming a generic samung_clk_register_pll() is their(which i think is
not impossible)
8<--------------------------------------------------------------------------

--- a/drivers/clk/samsung/clk-exynos5250.c
+++ b/drivers/clk/samsung/clk-exynos5250.c
@@ -493,6 +493,20 @@ static __initdata struct samsung_pll_rate_table
epll_24mhz_tbl[] = {
        PLL_36XX_RATE(32768000, 131, 3, 5, 4719),
 };

+struct __initdata samsung_pll_init_data samsung_plls[] = {
+       PLL(pll_3500, "fout_apll", "fin_pll", APLL_LOCK, APLL_CON0, NULL),
+       PLL(pll_3500, "fout_mpll", "fin_pll", MPLL_LOCK, MPLL_CON0, NULL),
+       PLL(pll_3500, "fout_bpll", "fin_pll",BPLL_LOCK, BPLL_CON0, NULL),
+       PLL(pll_3500, "fout_gpll", "fin_pll",GPLL_LOCK, GPLL_CON0, NULL),
+       PLL(pll_3500, "fout_cpll", "fin_pll",BPLL_LOCK, CPLL_CON0, NULL),
+};
+
+struct __initdata samsung_pll_init_data epll_init_data =
+       PLL(pll_3600, "fout_epll", "fin_pll", EPLL_LOCK, EPLL_CON0, NULL);
+
+struct __initdata samsung_pll_init_data vpll_init_data =
+       PLL(pll_3600, "fout_epll", "fin_pll", VPLL_LOCK, VPLL_CON0, NULL);
+
 /* register exynox5250 clocks */
 void __init exynos5250_clk_init(struct device_node *np)
 {
@@ -519,44 +533,22 @@ void __init exynos5250_clk_init(struct device_node *np)
        samsung_clk_register_mux(exynos5250_pll_pmux_clks,
                        ARRAY_SIZE(exynos5250_pll_pmux_clks));

-       fin_pll_rate = _get_rate("fin_pll");
+       samsung_clk_register_pll(samsung_plls, ARRAY_SIZE(samsung_plls));
+
        vpllsrc = __clk_lookup("mout_vpllsrc");
        if (vpllsrc)
                mout_vpllsrc_rate = clk_get_rate(vpllsrc);

-       apll = samsung_clk_register_pll35xx("fout_apll", "fin_pll",
-                       reg_base, NULL, 0);
-       mpll = samsung_clk_register_pll35xx("fout_mpll", "fin_pll",
-                       reg_base + 0x4000, NULL, 0);
-       bpll = samsung_clk_register_pll35xx("fout_bpll", "fin_pll",
-                       reg_base + 0x20010, NULL, 0);
-       gpll = samsung_clk_register_pll35xx("fout_gpll", "fin_pll",
-                       reg_base + 0x10050, NULL, 0);
-       cpll = samsung_clk_register_pll35xx("fout_cpll", "fin_pll",
-                       reg_base + 0x10020, NULL, 0);
-
+       fin_pll_rate = _get_rate("fin_pll");
        if (fin_pll_rate == (24 * MHZ)) {
-               epll = samsung_clk_register_pll36xx("fout_epll", "fin_pll",
-                               reg_base + 0x10030, epll_24mhz_tbl,
-                               ARRAY_SIZE(epll_24mhz_tbl));
-       } else {
-               pr_warn("%s: valid epll rate_table missing for\n"
-                       "parent fin_pll:%lu hz\n", __func__, fin_pll_rate);
-               epll = samsung_clk_register_pll36xx("fout_epll", "fin_pll",
-                               reg_base + 0x10030, NULL, 0);
+               epll_init_data.rate_table =  epll_24mhz_tb;
        }
+       samsung_clk_register_pll(&fout_epll_data, 1);

        if (mout_vpllsrc_rate == (24 * MHZ)) {
-               vpll = samsung_clk_register_pll36xx("fout_vpll", "mout_vpllsrc"
-                       , reg_base + 0x10040, vpll_24mhz_tbl,
-                       ARRAY_SIZE(vpll_24mhz_tbl));
-       } else {
-               pr_warn("%s: valid vpll rate_table missing for\n"
-                       "parent mout_vpllsrc_rate:%lu hz\n", __func__,
-                       mout_vpllsrc_rate);
-               samsung_clk_register_pll36xx("fout_vpll", "mout_vpllsrc",
-                       reg_base + 0x10040, NULL, 0);
+               vpll_init_data.rate_table =  epll_24mhz_tb;
        }
+       samsung_clk_register_pll(&fout_epll_data, 1);
        samsung_clk_register_fixed_rate(exynos5250_fixed_rate_clks,
                        ARRAY_SIZE(exynos5250_fixed_rate_clks));
diff --git a/drivers/clk/samsung/clk-pll.h b/drivers/clk/samsung/clk-pll.h
index 4780e6c..3b02dc5 100644
--- a/drivers/clk/samsung/clk-pll.h
+++ b/drivers/clk/samsung/clk-pll.h
@@ -39,6 +39,39 @@ struct samsung_pll_rate_table {
        unsigned int kdiv;
 };

+#define PLL(_type, _name, _pname, _lock_reg, _con_reg, _rate_table)    \
+       {                                                               \
+               .type   =       _type,                                  \
+               .name   =       _name,                                  \
+               .parent_name =  _pname,                                 \
+               .flags  =       CLK_GET_RATE_NOCACHE,                   \
+               .rate_table =   _rate_table,                            \
+               .con_reg =      _con_reg,                               \
+               .lock_reg =     _lock_reg,                              \
+       }
+
+enum samsung_pll_type {
+       pll_3500,
+       pll_45xx,
+       pll_2550,
+       pll_3600,
+       pll_46xx,
+       pll_2660,
+};
+
+
+struct samsung_pll_init_data {
+       enum            samsung_pll_type type;
+       struct          samsung_pll_rate_table *rate_table;
+       const char      *name;
+       const char      *parent_name;
+       unsigned long   flags;
+       const void __iomem *con_reg;
+       const void __iomem *lock_reg;
+};
+
+extern int  __init samsung_clk_register_pll(struct samsung_pll_init_data *data,
+                               unsigned int nr_pll);
+

Regards,
Yadwinder



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