On Thursday, August 22, 2013, Grant Grundler wrote: > On Wed, Aug 21, 2013 at 6:49 AM, Seungwon Jeon <tgih.jun@xxxxxxxxxxx> wrote: > > 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. > > I've refactored this code in ChromeOS-3.4 kernel. > Please see references to dw_mci_exynos_set_bus_hz() in: > https://gerrit.chromium.org/gerrit/#/c/57861/9/drivers/mmc/host/dw_mmc-exynos.c > > Have you considered using that code? Perhaps Alim didn't point out > this work to you? > > It might be easier to read here: > > http://git.chromium.org/gitweb/?p=chromiumos/third_party/kernel.git;a=blob;f=drivers/mmc/host/dw_mmc.c > ;h=41ff5a0d79dffb488a413c51ba14024d4dda1275;hb=refs/heads/chromeos-3.4 > > The same code was adopted for ChromeOS-3.8 kernel tree: > http://git.chromium.org/gitweb/?p=chromiumos/third_party/kernel- > next.git;a=commitdiff;h=39ae94e55a0ad4584b5ff85e2a342a5f867c4d21 > > http://git.chromium.org/gitweb/?p=chromiumos/third_party/kernel- > next.git;a=history;f=drivers/mmc/host/dw_mmc- > exynos.c;h=a8288d4c9fac8b89dadff5d4bde469c43171c9cf;hb=refs/heads/chromeos-3.8 The codes related to tuning feature have been introduced and opened already in Android kernel from our side. Basically this changes are based on below and updated with latest kernel: @ mmc: dw_mmc: add support of tuning feature https://android.googlesource.com/kernel/exynos/+/016ebd43ab27cf8b0258d1e7d3e3288d7f7aab6a%5E%21/#F0 @ ARM: EXYNOS: adjust the clock rate for mmcx https://android.googlesource.com/kernel/exynos/+/13afd72b983cc0438a295fa827ff1246fed148b2%5E%21/#F0 Thanks, Seungwon Jeon > thanks, > grant > > > > > Signed-off-by: Seungwon Jeon <tgih.jun@xxxxxxxxxxx> > > --- > > 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 majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
