Hi Oleksandr, On Tue, Aug 31, 2021 at 8:49 PM Oleksandr Suvorov <[email protected]> wrote: > > Import HS400 support for iMX7ULP B0 from the Linux kernel: > > 2eaf5a533afd ("mmc: sdhci-esdhc-imx: Add HS400 support for iMX7ULP") > > According to IC suggest, need to clear the STROBE_DLL_CTRL_RESET > before any setting of STROBE_DLL_CTRL register. > > USDHC has register bits(bit[27~20] of register STROBE_DLL_CTRL) > for slave sel value. If this register bits value is 0, it needs > 256 ref_clk cycles to update slave sel value. IC suggest to set > bit[27~20] to 0x4, it only need 4 ref_clk cycle to update slave > sel value. This will short the lock time of slave. > > i.MX7ULP B0 will need more time to lock the REF and SLV, so change > to add 5us delay. > > Signed-off-by: Oleksandr Suvorov <[email protected]> > Reviewed-by: Fabio Estevam <[email protected]> > --- > > Changes in v2: > - fixed Series-notes record. > - added Reviewed-by records. > > drivers/mmc/fsl_esdhc_imx.c | 11 ++++++++--- > include/fsl_esdhc_imx.h | 1 + > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/fsl_esdhc_imx.c b/drivers/mmc/fsl_esdhc_imx.c > index 6c8f77f9ee..569f099d9b 100644 > --- a/drivers/mmc/fsl_esdhc_imx.c > +++ b/drivers/mmc/fsl_esdhc_imx.c > @@ -727,17 +727,21 @@ static void esdhc_set_strobe_dll(struct mmc *mmc) > > if (priv->clock > ESDHC_STROBE_DLL_CLK_FREQ) { > esdhc_write32(®s->strobe_dllctrl, > ESDHC_STROBE_DLL_CTRL_RESET); > + /* clear the reset bit on strobe dll before any setting */ > + esdhc_write32(®s->strobe_dllctrl, 0); > + minor: additional blank line isn't needed. > > /* > * enable strobe dll ctrl and adjust the delay target > * for the uSDHC loopback read clock > */ > val = ESDHC_STROBE_DLL_CTRL_ENABLE | > + ESDHC_STROBE_DLL_CTRL_SLV_UPDATE_INT_DEFAULT | > (priv->strobe_dll_delay_target << > ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT); > esdhc_write32(®s->strobe_dllctrl, val); > - /* wait 1us to make sure strobe dll status register stable */ > - mdelay(1); > + /* wait 5us to make sure strobe dll status register stable */ > + mdelay(5); > val = esdhc_read32(®s->strobe_dllstat); > if (!(val & ESDHC_STROBE_DLL_STS_REF_LOCK)) > pr_warn("HS400 strobe DLL status REF not lock!\n"); > @@ -1708,7 +1712,8 @@ static struct esdhc_soc_data usdhc_imx7d_data = { > > static struct esdhc_soc_data usdhc_imx7ulp_data = { > .flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING > - | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200, > + | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200 > + | ESDHC_FLAG_HS400, > }; > > static struct esdhc_soc_data usdhc_imx8qm_data = { > diff --git a/include/fsl_esdhc_imx.h b/include/fsl_esdhc_imx.h > index 45ed635a77..12e9163382 100644 > --- a/include/fsl_esdhc_imx.h > +++ b/include/fsl_esdhc_imx.h > @@ -194,6 +194,7 @@ > #define ESDHC_STROBE_DLL_CTRL_RESET BIT(1) > #define ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_DEFAULT 0x7 > #define ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT 3 > +#define ESDHC_STROBE_DLL_CTRL_SLV_UPDATE_INT_DEFAULT (4 << 20) > > #define ESDHC_STROBE_DLL_STATUS 0x74 > #define ESDHC_STROBE_DLL_STS_REF_LOCK BIT(1) > -- > 2.31.1 >
Reviewed-by: Igor Opaniuk <[email protected]> -- Best regards - Freundliche Grüsse - Meilleures salutations Igor Opaniuk Embedded Software Engineer T: +380 938364067 E: [email protected] W: www.foundries.io
