Re: [PATCHv2 09/21] mmc: sdhci-of-dwcmshc: add reset call back for rockchip Socs

[Sebastian Reichel]

Hi,

On Fri, May 06, 2022 at 10:52:42AM +0200, Ulf Hansson wrote:
> On Wed, 4 May 2022 at 23:33, Sebastian Reichel
> <sebastian.reichel@xxxxxxxxxxxxx> wrote:
> >
> > From: Yifeng Zhao <yifeng.zhao@xxxxxxxxxxxxxx>
> >
> > The reset function build in the SDHCI will not reset the logic
> > circuit related to the tuning function, which may cause data
> > reading errors. Resetting the complete SDHCI controller through
> > the reset controller fixes the issue.
> >
> > Signed-off-by: Yifeng Zhao <yifeng.zhao@xxxxxxxxxxxxxx>
> > [rebase, use optional variant of reset getter]
> > Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> > Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
> 
> I think this needs a corresponding update of the DT docs. Otherwise
> this looks good to me.

I do have 'resets' and 'reset-names' properties in the rk3588s.dtsi
for the sdhci interface and 'make dtbs_check' did not complain about
anything but missing 'arm,sdei-1.0' compatible for the rk3588 EVB
(sdei binding has not yet been converted to yaml). Thus I assume the
resets property is inferred from somewhere?

-- Sebastian

> 
> Kind regards
> Uffe
> 
> > ---
> >  drivers/mmc/host/sdhci-of-dwcmshc.c | 26 +++++++++++++++++++++++++-
> >  1 file changed, 25 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > index bac874ab0b33..3a1b5ba36405 100644
> > --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> > +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > @@ -15,6 +15,7 @@
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> >  #include <linux/of_device.h>
> > +#include <linux/reset.h>
> >  #include <linux/sizes.h>
> >
> >  #include "sdhci-pltfm.h"
> > @@ -63,6 +64,7 @@
> >  struct rk3568_priv {
> >         /* Rockchip specified optional clocks */
> >         struct clk_bulk_data rockchip_clks[RK3568_MAX_CLKS];
> > +       struct reset_control *reset;
> >         u8 txclk_tapnum;
> >  };
> >
> > @@ -255,6 +257,21 @@ static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock
> >         sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_STRBIN);
> >  }
> >
> > +static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
> > +{
> > +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > +       struct dwcmshc_priv *dwc_priv = sdhci_pltfm_priv(pltfm_host);
> > +       struct rk35xx_priv *priv = dwc_priv->priv;
> > +
> > +       if (mask & SDHCI_RESET_ALL && priv->reset) {
> > +               reset_control_assert(priv->reset);
> > +               udelay(1);
> > +               reset_control_deassert(priv->reset);
> > +       }
> > +
> > +       sdhci_reset(host, mask);
> > +}
> > +
> >  static const struct sdhci_ops sdhci_dwcmshc_ops = {
> >         .set_clock              = sdhci_set_clock,
> >         .set_bus_width          = sdhci_set_bus_width,
> > @@ -269,7 +286,7 @@ static const struct sdhci_ops sdhci_dwcmshc_rk3568_ops = {
> >         .set_bus_width          = sdhci_set_bus_width,
> >         .set_uhs_signaling      = dwcmshc_set_uhs_signaling,
> >         .get_max_clock          = sdhci_pltfm_clk_get_max_clock,
> > -       .reset                  = sdhci_reset,
> > +       .reset                  = rk35xx_sdhci_reset,
> >         .adma_write_desc        = dwcmshc_adma_write_desc,
> >  };
> >
> > @@ -292,6 +309,13 @@ static int dwcmshc_rk3568_init(struct sdhci_host *host, struct dwcmshc_priv *dwc
> >         int err;
> >         struct rk3568_priv *priv = dwc_priv->priv;
> >
> > +       priv->reset = devm_reset_control_array_get_optional_exclusive(mmc_dev(host->mmc));
> > +       if (IS_ERR(priv->reset)) {
> > +               err = PTR_ERR(priv->reset);
> > +               dev_err(mmc_dev(host->mmc), "failed to get reset control %d\n", err);
> > +               return err;
> > +       }
> > +
> >         priv->rockchip_clks[0].id = "axi";
> >         priv->rockchip_clks[1].id = "block";
> >         priv->rockchip_clks[2].id = "timer";
> > --
> > 2.35.1
> >

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