Hi, >Hi Akshay, > >On 02/03/2015 05:27 PM, Akshay Saraswat wrote: >> Cleaning up soc_get_periph_rate to make the logic easy to >> comprehend. >> > >Could you give more detailed description?
We did just a cleanup here by removing I2C sepecific calculations because we can now have a generic div and pre-div calculation. Only intention of doing it is making code clean and easily understandable. I don't know what else to write for that. Please suggest. :) > >> Signed-off-by: Akshay Saraswat <[email protected]> >> --- >> Changes since v4: >> - New patch. >> >> arch/arm/cpu/armv7/exynos/clock.c | 76 >> +++++++++++++++++---------------------- >> 1 file changed, 33 insertions(+), 43 deletions(-) >> >> diff --git a/arch/arm/cpu/armv7/exynos/clock.c >> b/arch/arm/cpu/armv7/exynos/clock.c >> index 3884d4b..8724bc7 100644 >> --- a/arch/arm/cpu/armv7/exynos/clock.c >> +++ b/arch/arm/cpu/armv7/exynos/clock.c >> @@ -366,8 +366,8 @@ static struct clk_bit_info *get_clk_bit_info(int >> peripheral) >> static unsigned long exynos5_get_periph_rate(int peripheral) >> { >> struct clk_bit_info *bit_info = get_clk_bit_info(peripheral); >> - unsigned long sclk, sub_clk = 0; >> - unsigned int src, div, sub_div = 0; >> + unsigned long sclk = 0; >> + unsigned int src = 0, div = 0, sub_div = 0; >> struct exynos5_clock *clk = >> (struct exynos5_clock *)samsung_get_base_clock(); >> >> @@ -389,30 +389,30 @@ static unsigned long exynos5_get_periph_rate(int >> peripheral) >> break; >> case PERIPH_ID_I2S0: >> src = readl(&clk->src_mau); >> - div = readl(&clk->div_mau); >> + div = sub_div = readl(&clk->div_mau); >> case PERIPH_ID_SPI0: >> case PERIPH_ID_SPI1: >> src = readl(&clk->src_peric1); >> - div = readl(&clk->div_peric1); >> + div = sub_div = readl(&clk->div_peric1); >> break; >> case PERIPH_ID_SPI2: >> src = readl(&clk->src_peric1); >> - div = readl(&clk->div_peric2); >> + div = sub_div = readl(&clk->div_peric2); >> break; >> case PERIPH_ID_SPI3: >> case PERIPH_ID_SPI4: >> src = readl(&clk->sclk_src_isp); >> - div = readl(&clk->sclk_div_isp); >> + div = sub_div = readl(&clk->sclk_div_isp); >> break; >> case PERIPH_ID_SDMMC0: >> case PERIPH_ID_SDMMC1: >> src = readl(&clk->src_fsys); >> - div = readl(&clk->div_fsys1); >> + div = sub_div = readl(&clk->div_fsys1); >> break; >> case PERIPH_ID_SDMMC2: >> case PERIPH_ID_SDMMC3: >> src = readl(&clk->src_fsys); >> - div = readl(&clk->div_fsys2); >> + div = sub_div = readl(&clk->div_fsys2); >> break; >> case PERIPH_ID_I2C0: >> case PERIPH_ID_I2C1: >> @@ -422,12 +422,10 @@ static unsigned long exynos5_get_periph_rate(int >> peripheral) >> case PERIPH_ID_I2C5: >> case PERIPH_ID_I2C6: >> case PERIPH_ID_I2C7: >> - sclk = exynos5_get_pll_clk(MPLL); >> - sub_div = ((readl(&clk->div_top1) >> bit_info->div_bit) >> - & bit_info->div_mask) + 1; >> - div = ((readl(&clk->div_top0) >> bit_info->prediv_bit) >> - & bit_info->prediv_mask) + 1; >> - return (sclk / sub_div) / div; >> + src = EXYNOS_SRC_MPLL; >> + div = readl(&clk->div_top0); >> + sub_div = readl(&clk->div_top1); >> + break; >> default: >> debug("%s: invalid peripheral %d", __func__, peripheral); >> return -1; >> @@ -446,29 +444,26 @@ static unsigned long exynos5_get_periph_rate(int >> peripheral) >> case EXYNOS_SRC_VPLL: >> sclk = exynos5_get_pll_clk(VPLL); >> break; >> - default: >> - return 0; > >Why remove? I think it's better to use default label and also how about >add debug log? Removing because anyways we are going to calculate & return 0 for non-existent src or sclk. I have initialized src and sclk above with value zero. > >> } >> >> - /* Ratio clock division for this peripheral */ >> - if (bit_info->div_bit >= 0) { >> - sub_div = (div >> bit_info->div_bit) & bit_info->div_mask; >> - sub_clk = sclk / (sub_div + 1); >> - } >> + /* Clock divider ratio for this peripheral */ >> + if (bit_info->div_bit >= 0) >> + div = (div >> bit_info->div_bit) & bit_info->div_mask; >> >> - if (bit_info->prediv_bit >= 0) { >> - div = (div >> bit_info->prediv_bit) & bit_info->prediv_mask; >> - return sub_clk / (div + 1); >> - } >> + /* Clock pre-divider ratio for this peripheral */ >> + if (bit_info->prediv_bit >= 0) >> + sub_div = (sub_div >> bit_info->prediv_bit) >> + & bit_info->prediv_mask; >> >> - return sub_clk; >> + /* Calculate and return required clock rate */ >> + return (sclk / (div + 1)) / (sub_div + 1); >> } >> >> static unsigned long exynos542x_get_periph_rate(int peripheral) >> { >> struct clk_bit_info *bit_info = get_clk_bit_info(peripheral); >> - unsigned long sclk, sub_clk = 0; >> - unsigned int src, div, sub_div = 0; >> + unsigned long sclk = 0; >> + unsigned int src = 0, div = 0, sub_div = 0; >> struct exynos5420_clock *clk = >> (struct exynos5420_clock *)samsung_get_base_clock(); >> >> @@ -516,10 +511,9 @@ static unsigned long exynos542x_get_periph_rate(int >> peripheral) >> case PERIPH_ID_I2C8: >> case PERIPH_ID_I2C9: >> case PERIPH_ID_I2C10: >> - sclk = exynos542x_get_pll_clk(MPLL); >> - sub_div = ((readl(&clk->div_top1) >> bit_info->div_bit) >> - & bit_info->div_mask) + 1; >> - return sclk / sub_div; >> + src = EXYNOS542X_SRC_MPLL; >> + div = readl(&clk->div_top1); >> + break; >> default: >> debug("%s: invalid peripheral %d", __func__, peripheral); >> return -1; >> @@ -541,23 +535,19 @@ static unsigned long exynos542x_get_periph_rate(int >> peripheral) >> case EXYNOS542X_SRC_RPLL: >> sclk = exynos542x_get_pll_clk(RPLL); >> break; >> - default: >> - return 0; > >Ditto. > >> } >> >> - /* Ratio clock division for this peripheral */ >> - if (bit_info->div_bit >= 0) { >> + /* Clock divider ratio for this peripheral */ >> + if (bit_info->div_bit >= 0) >> div = (div >> bit_info->div_bit) & bit_info->div_mask; >> - sub_clk = sclk / (div + 1); >> - } >> >> - if (bit_info->prediv_bit >= 0) { >> + /* Clock pre-divider ratio for this peripheral */ >> + if (bit_info->prediv_bit >= 0) >> sub_div = (sub_div >> bit_info->prediv_bit) >> - & bit_info->prediv_mask; >> - return sub_clk / (sub_div + 1); >> - } >> + & bit_info->prediv_mask; >> >> - return sub_clk; >> + /* Calculate and return required clock rate */ >> + return (sclk / (div + 1)) / (sub_div + 1); >> } >> >> unsigned long clock_get_periph_rate(int peripheral) >> > >Thanks. > Regards, Akshay Saraswat _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
