Re: [PATCH V2 2/4] mmc: sdhci-msm: Add msm version specific ops and data structures

[Vijay Viswanath]

Hi Stephen,

On 6/13/2018 5:06 AM, Stephen Boyd wrote:
> Quoting Vijay Viswanath (2018-05-29 02:52:39)
> > diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> > index 4050c99..2a66aa0 100644
> > --- a/drivers/mmc/host/sdhci-msm.c
> > +++ b/drivers/mmc/host/sdhci-msm.c
> > @@ -226,6 +226,24 @@ struct sdhci_msm_offset {
> >          .core_ddr_config_2 = 0x1bc,
> >   };
> >   
> > +struct sdhci_msm_variant_ops {
> > +       u8 (*msm_readb_relaxed)(struct sdhci_host *host, u32 offset);
> > +       u32 (*msm_readl_relaxed)(struct sdhci_host *host, u32 offset);
> > +       void (*msm_writeb_relaxed)(u8 val, struct sdhci_host *host, u32 offset);
> > +       void (*msm_writel_relaxed)(u32 val, struct sdhci_host *host,
> > +                       u32 offset);
> > +};
> > +
> > +/*
> > + * From V5, register spaces have changed. Wrap this info in a structure
> > + * and choose the data_structure based on version info mentioned in DT.
> > + */
>
> This is sort of odd. Usually we have a read/write function that swizzles
> based on register variants, and that's contained with that function. Now
> it's the other way.
>
> > +struct sdhci_msm_variant_info {
> > +       bool mci_removed;
> > +       const struct sdhci_msm_variant_ops *var_ops;
> > +       const struct sdhci_msm_offset *offset;
> > +};
> > +
> >   struct sdhci_msm_host {
> >          struct platform_device *pdev;
> >          void __iomem *core_mem; /* MSM SDCC mapped address */
> > @@ -245,8 +263,45 @@ struct sdhci_msm_host {
> >          wait_queue_head_t pwr_irq_wait;
> >          bool pwr_irq_flag;
> >          u32 caps_0;
> > +       bool mci_removed;
> > +       const struct sdhci_msm_variant_ops *var_ops;
> > +       const struct sdhci_msm_offset *offset;
> >   };
> >   
> > +/*
> > + * APIs to read/write to vendor specific registers which were there in the
> > + * core_mem region before MCI was removed.
> > + */
> > +static u32 sdhci_msm_mci_variant_readl_relaxed(struct sdhci_host *host,
> > +               u32 offset)
> > +{
> > +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > +       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> > +
> > +       return readl_relaxed(msm_host->core_mem + offset);
>
> Is core_mem assigned in the new hardware? Maybe that needs to be
> 'repurposed' for vendor specific registers on v5 and renamed to
> something like msm_host::vendor_base or something like that.

There is no core_mem in the new hardware. We can assign hc_mem address 
to core_mem variable (if SDCC5) and do away with the need of special 
read/write functions, but I feel thats a bad approach and misleading.

> > +}
> > +
> > +static u32 sdhci_msm_v5_variant_readl_relaxed(struct sdhci_host *host,
> > +               u32 offset)
> > +{
> > +       return readl_relaxed(host->ioaddr + offset);
> > +}
> > +
> > +static void sdhci_msm_mci_variant_writel_relaxed(u32 val,
> > +               struct sdhci_host *host, u32 offset)
> > +{
> > +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > +       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> > +
> > +       writel_relaxed(val, msm_host->core_mem + offset);
> > +}
> > +
> > +static void sdhci_msm_v5_variant_writel_relaxed(u32 val,
> > +               struct sdhci_host *host, u32 offset)
> > +{
> > +       writel_relaxed(val, host->ioaddr + offset);
> > +}
> > +
> >   static unsigned int msm_get_clock_rate_for_bus_mode(struct sdhci_host *host,
> >                                                      unsigned int clock)
> >   {
> > @@ -1481,6 +1536,28 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
> >          pr_debug("%s: supported caps: 0x%08x\n", mmc_hostname(mmc), caps);
> >   }
> >   
> > +static const struct sdhci_msm_variant_ops mci_var_ops = {
> > +       .msm_readl_relaxed = sdhci_msm_mci_variant_readl_relaxed,
> > +       .msm_writel_relaxed = sdhci_msm_mci_variant_writel_relaxed,
> > +};
> > +
> > +static const struct sdhci_msm_variant_ops v5_var_ops = {
> > +       .msm_readl_relaxed = sdhci_msm_v5_variant_readl_relaxed,
> > +       .msm_writel_relaxed = sdhci_msm_v5_variant_writel_relaxed,
> > +};
> > +
> > +static const struct sdhci_msm_variant_info sdhci_msm_mci_var = {
> > +       .mci_removed = 0,
>
> Please use true and false instead of 0 and 1 when the type is bool.

Will do

> > +       .var_ops = &mci_var_ops,
> > +       .offset = &sdhci_msm_mci_offset,
> > +};
> > +
> > +static const struct sdhci_msm_variant_info sdhci_msm_v5_var = {
> > +       .mci_removed = 1,
> > +       .var_ops = &v5_var_ops,
> > +       .offset = &sdhci_msm_v5_offset,
> > +};
> --
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