[U-Boot] [PATCH V3 5/9] EXYNOS5: DWMMC: API to set mmc clock divisor

Jaehoon Chung
2013-01-02T03:31:36Z

Hi Amar,

On 12/31/2012 07:58 PM, Amar wrote:
> This API computes the divisor value based on MPLL clock and
> writes it into the FSYS1 register.
>
> Changes from V1:
> 1)Updated the function exynos5_mmc_set_clk_div() to receive
> 'device_i'd as input parameter instead of 'index'.
>
> Changes from V2:
> 1)Updation of commit message and resubmition of proper patch set.
>
> Signed-off-by: Amar <amarendra.xt@samsung.com>
> ---
> arch/arm/cpu/armv7/exynos/clock.c | 38 ++++++++++++++++++++++++++++++++--
> arch/arm/include/asm/arch-exynos/clk.h | 4 ++++
> 2 files changed, 40 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
> index 973b84e..cd42689 100644
> --- a/arch/arm/cpu/armv7/exynos/clock.c
> +++ b/arch/arm/cpu/armv7/exynos/clock.c
> @@ -490,7 +490,7 @@ static unsigned long exynos4_get_mmc_clk(int dev_index)
> (struct exynos4_clock *)samsung_get_base_clock();
> unsigned long uclk, sclk;
> unsigned int sel, ratio, pre_ratio;
> - int shift;
> + int shift = 0;
>
> sel = readl(&clk->src_fsys);
> sel = (sel >> (dev_index << 2)) & 0xf;
> @@ -539,7 +539,7 @@ static unsigned long exynos5_get_mmc_clk(int dev_index)
> (struct exynos5_clock *)samsung_get_base_clock();
> unsigned long uclk, sclk;
> unsigned int sel, ratio, pre_ratio;
> - int shift;
> + int shift = 0;
>
> sel = readl(&clk->src_fsys);
> sel = (sel >> (dev_index << 2)) & 0xf;
> @@ -659,6 +659,40 @@ static void exynos5_set_mmc_clk(int dev_index, unsigned int div)
> writel(val, addr);
> }
>
> +/* exynos5: set the mmc clock div ratio in fsys1 */
> +int exynos5_mmc_set_clk_div(int dev_id)
Why return the int type?
> +{
> + struct exynos5_clock *clk =
> + (struct exynos5_clock *)samsung_get_base_clock();
> + unsigned int addr;
> + unsigned int clock;
> + unsigned int tmp;
> + unsigned int i;
Can't use unsigned int addr, clock....? We can save the line.
> +
> + /* get mpll clock */
> + clock = get_pll_clk(MPLL) / 1000000;
> +
> + /*
> + * CLK_DIV_FSYS1
> + * MMC0_PRE_RATIO [15:8], MMC0_RATIO [3:0]
> + * CLK_DIV_FSYS2
> + * MMC2_PRE_RATIO [15:8], MMC2_RATIO [3:0]
> + */
> + if (dev_id <= PERIPH_ID_SDMMC1)
> + addr = (unsigned int)&clk->div_fsys1;
> + else
> + addr = (unsigned int)&clk->div_fsys2;
> +
> + tmp = readl(addr) & ~FSYS1_MMC0_DIV_MASK;
FSYS1_MMC0_DIV_MASK? then case of MMC2?
It is wrong macro name..You also used the clk->div_fsys2..
> + for (i = 0; i <= 0xf; i++) {
> + if ((clock / (i + 1)) <= 400) {
> + writel(tmp | i << 0, addr);
> + break;
> + }
> + }
> + return 0;
> +}
I didn't understand this function(exynos5_mmc_set_clk_div?).
What purpose? I think good that proper to use the "div" as argument.
void exynos5_mmc_set_clk(int dev_id, unsigned int div).
> +
> /* get_lcd_clk: return lcd clock frequency */
> static unsigned long exynos4_get_lcd_clk(void)
> {
> diff --git a/arch/arm/include/asm/arch-exynos/clk.h b/arch/arm/include/asm/arch-exynos/clk.h
> index 1935b0b..2fd7c3e 100644
> --- a/arch/arm/include/asm/arch-exynos/clk.h
> +++ b/arch/arm/include/asm/arch-exynos/clk.h
> @@ -29,6 +29,9 @@
> #define VPLL 4
> #define BPLL 5
>
> +#define FSYS1_MMC0_DIV_MASK 0xff0f
> +#define FSYS1_MMC0_DIV_VAL 0x0701
> +
> unsigned long get_pll_clk(int pllreg);
> unsigned long get_arm_clk(void);
> unsigned long get_i2c_clk(void);
> @@ -36,6 +39,7 @@ unsigned long get_pwm_clk(void);
> unsigned long get_uart_clk(int dev_index);
> unsigned long get_mmc_clk(int dev_index);
> void set_mmc_clk(int dev_index, unsigned int div);
> +int exynos5_mmc_set_clk_div(int dev_index);
> unsigned long get_lcd_clk(void);
> void set_lcd_clk(void);
> void set_mipi_clk(void);
>