[U-Boot] [PATCH 07/10 V4] EXYNOS5: CLOCK: Modify MPLL clock out for Exynos5250 Rev 1.0

Joonyoung Shim dofmind at gmail.com
Mon Jul 2 11:52:38 CEST 2012


2012/6/29 Rajeshwari Shinde <rajeshwari.s at samsung.com>:
> MPLL clock-out of Exynos5250 Rev 1.0 is always at 1.6GHz.
> Adjust the divisor value to get 800MHz as needed by devices
> like UART etc
>
> Signed-off-by: Hatim Ali <hatim.rv at samsung.com>
> Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com>
> ---
> Changes in V2:
>        - None
> Changes in V3:
>         -  Incorported review comments from Minkyu Kang.
> Changes in V4:
>         - None
>  arch/arm/cpu/armv7/exynos/clock.c        |   12 +++++++++++-
>  arch/arm/include/asm/arch-exynos/clock.h |    3 +++
>  2 files changed, 14 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
> index 330bd75..dbd5f11 100644
> --- a/arch/arm/cpu/armv7/exynos/clock.c
> +++ b/arch/arm/cpu/armv7/exynos/clock.c
> @@ -98,7 +98,7 @@ static unsigned long exynos5_get_pll_clk(int pllreg)
>         struct exynos5_clock *clk =
>                 (struct exynos5_clock *)samsung_get_base_clock();
>         unsigned long r, m, p, s, k = 0, mask, fout;
> -       unsigned int freq;
> +       unsigned int freq, pll_div2_sel,  mpll_fout_sel;
>
>         switch (pllreg) {
>         case APLL:
> @@ -155,6 +155,16 @@ static unsigned long exynos5_get_pll_clk(int pllreg)
>                 fout = m * (freq / (p * (1 << (s - 1))));
>         }
>
> +       /* According to the user manual, in EVT1 MPLL always gives
> +        * 1.6GHz clock, so divide by 2 to get 800MHz MPLL clock.*/
> +       if (pllreg == MPLL) {
> +               pll_div2_sel = readl(&clk->pll_div2_sel);
> +               mpll_fout_sel = (pll_div2_sel >> MPLL_FOUT_SEL_SHIFT)
> +                               & MPLL_FOUT_SEL_MASK;
> +               if (mpll_fout_sel == 0)
> +                       fout /= 2;
> +       }
> +
>         return fout;
>  }
>
> diff --git a/arch/arm/include/asm/arch-exynos/clock.h b/arch/arm/include/asm/arch-exynos/clock.h
> index 90271f1..bf41c19 100644
> --- a/arch/arm/include/asm/arch-exynos/clock.h
> +++ b/arch/arm/include/asm/arch-exynos/clock.h
> @@ -596,4 +596,7 @@ struct exynos5_clock {
>         unsigned char   res123[0xf5d8];
>  };
>  #endif
> +
> +#define MPLL_FOUT_SEL_SHIFT    4
> +#define MPLL_FOUT_SEL_MASK     0x1
>  #endif
> --
> 1.7.4.4
>

Acked-by: Joonyoung Shim <jy0922.shim at samsung.com>

-- 
- Joonyoung Shim


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