Re: [PATCH v12 13/15] mmc: sdhci-cadence: Add AMD Pensando Elba SoC support

From: Andy Shevchenko
Date: Thu Mar 23 2023 - 06:45:53 EST


On Thu, Mar 23, 2023 at 2:10 AM Brad Larson <blarson@xxxxxxx> wrote:
>
> Add support for AMD Pensando Elba SoC which explicitly
> controls byte-lane enables on writes.
>
> Select MMC_SDHCI_IO_ACCESSORS for MMC_SDHCI_CADENCE which
> allows Elba SoC sdhci_elba_ops to overwrite the SDHCI
> IO memory accessors


> +/* Elba control register bits [6:3] are byte-lane enables */
> +#define ELBA_BYTE_ENABLE_MASK(x) ((x) << 3)


> +static void elba_priv_writel(struct sdhci_cdns_priv *priv, u32 val,
> + void __iomem *reg)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&priv->wrlock, flags);
> + writel(ELBA_BYTE_ENABLE_MASK(0xf), priv->ctl_addr);

GENMASK(3, 0) ?

> + writel(val, reg);
> + spin_unlock_irqrestore(&priv->wrlock, flags);
> +}

...

> + byte_enables = GENMASK(1, 0) << (reg & 0x3);

unsigned u32 shift = reg & GENMASK(1, 0);

byte_enables = GENMASK(1, 0) << shift;

?

...

> + byte_enables = BIT(0) << (reg & 0x3);

In a similar way?

unsigned u32 shift = reg & GENMASK(1, 0);

byte_enables = BIT(0) << shift;

--
With Best Regards,
Andy Shevchenko