Exynos's host has divider logic before 'cclk_in' to controller core. It means that actual clock rate of ciu clock comes from this divider value. So, source clock should be adjusted along with 'ciu_div' which indicates the host's divider ratio. Setting clock rate basically fits the required speed. Specially, 'cclk_in' should have double rate of target speed in case of DDR 8-bit mode.
Signed-off-by: Seungwon Jeon <[email protected]> --- drivers/mmc/host/dw_mmc-exynos.c | 44 ++++++++++++++++++++++++++++--------- 1 files changed, 33 insertions(+), 11 deletions(-) diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c index 90f9335..f16e2fc 100644 --- a/drivers/mmc/host/dw_mmc-exynos.c +++ b/drivers/mmc/host/dw_mmc-exynos.c @@ -49,6 +49,7 @@ struct dw_mci_exynos_priv_data { u8 ciu_div; u32 sdr_timing; u32 ddr_timing; + u32 cur_speed; }; static struct dw_mci_exynos_compatible { @@ -91,14 +92,9 @@ static int dw_mci_exynos_priv_init(struct dw_mci *host) static int dw_mci_exynos_setup_clock(struct dw_mci *host) { struct dw_mci_exynos_priv_data *priv = host->priv; + unsigned long rate = clk_get_rate(host->ciu_clk); - if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250) - host->bus_hz /= (priv->ciu_div + 1); - else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412) - host->bus_hz /= EXYNOS4412_FIXED_CIU_CLK_DIV; - else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210) - host->bus_hz /= EXYNOS4210_FIXED_CIU_CLK_DIV; - + host->bus_hz = rate / (priv->ciu_div + 1); return 0; } @@ -118,11 +114,31 @@ static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr) static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios) { struct dw_mci_exynos_priv_data *priv = host->priv; + unsigned int wanted = ios->clock; + unsigned long actual; + u8 div = priv->ciu_div + 1; + - if (ios->timing == MMC_TIMING_UHS_DDR50) + if (ios->timing == MMC_TIMING_UHS_DDR50) { mci_writel(host, CLKSEL, priv->ddr_timing); - else + /* Should be double rate for DDR mode */ + if (ios->bus_width == MMC_BUS_WIDTH_8) + wanted <<= 1; + } else { mci_writel(host, CLKSEL, priv->sdr_timing); + } + + if (wanted && (priv->cur_speed != wanted)) { + int ret = clk_set_rate(host->ciu_clk, wanted * div); + if (ret) + dev_warn(host->dev, + "failed to set clk-rate %u error: %d\n", + wanted * div, ret); + actual = clk_get_rate(host->ciu_clk); + host->bus_hz = actual / div; + priv->cur_speed = wanted; + host->current_speed = 0; + } } static int dw_mci_exynos_parse_dt(struct dw_mci *host) @@ -133,8 +149,14 @@ static int dw_mci_exynos_parse_dt(struct dw_mci *host) u32 div = 0; int ret; - of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div); - priv->ciu_div = div; + if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412) + priv->ciu_div = EXYNOS4412_FIXED_CIU_CLK_DIV - 1; + else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210) + priv->ciu_div = EXYNOS4210_FIXED_CIU_CLK_DIV - 1; + else { + of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div); + priv->ciu_div = div; + } ret = of_property_read_u32_array(np, "samsung,dw-mshc-sdr-timing", timing, 2); -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
