Re: [PATCH v10 11/15] mmc: sdhci-cadence: Enable device specific override of writel()

[Adrian Hunter]

On 6/03/23 06:07, Brad Larson wrote:
> SoCs with device specific Cadence implementation, such as setting
> byte-enables before the write, need to override writel().  Add a
> callback where the default is writel() for all existing chips.
> 
> Signed-off-by: Brad Larson <blarson@xxxxxxx>

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
> 
> v10 changes:
> - The 1st patch adding private writel() is unchanged.  The 2nd patch is split
>   into two patches to provide for device specific init in one patch with no
>   effect on existing designs.  Then add the pensando support into the next patch.
>   Then the 4th patch is mmc hardware reset support which is unchanged.
> 
> v9 changes:
> - No change to this patch but as some patches are deleted and this is
>   a respin the three successive patches to sdhci-cadence.c are
>   patches 12, 13, and 14 which do the following:
> 
>   1. Add ability for Cadence specific design to have priv writel().
>   2. Add Elba SoC support that requires its own priv writel() for
>      byte-lane control .
>   3. Add support for mmc hardware reset.
> 
> ---
>  drivers/mmc/host/sdhci-cadence.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
> index 6f2de54a5987..708d4297f241 100644
> --- a/drivers/mmc/host/sdhci-cadence.c
> +++ b/drivers/mmc/host/sdhci-cadence.c
> @@ -67,6 +67,7 @@ struct sdhci_cdns_phy_param {
>  struct sdhci_cdns_priv {
>  	void __iomem *hrs_addr;
>  	bool enhanced_strobe;
> +	void (*priv_writel)(struct sdhci_cdns_priv *priv, u32 val, void __iomem *reg);
>  	unsigned int nr_phy_params;
>  	struct sdhci_cdns_phy_param phy_params[];
>  };
> @@ -90,6 +91,12 @@ static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
>  	{ "cdns,phy-dll-delay-strobe", SDHCI_CDNS_PHY_DLY_STROBE, },
>  };
>  
> +static inline void cdns_writel(struct sdhci_cdns_priv *priv, u32 val,
> +			       void __iomem *reg)
> +{
> +	writel(val, reg);
> +}
> +
>  static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
>  				    u8 addr, u8 data)
>  {
> @@ -104,17 +111,17 @@ static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
>  
>  	tmp = FIELD_PREP(SDHCI_CDNS_HRS04_WDATA, data) |
>  	      FIELD_PREP(SDHCI_CDNS_HRS04_ADDR, addr);
> -	writel(tmp, reg);
> +	priv->priv_writel(priv, tmp, reg);
>  
>  	tmp |= SDHCI_CDNS_HRS04_WR;
> -	writel(tmp, reg);
> +	priv->priv_writel(priv, tmp, reg);
>  
>  	ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
>  	if (ret)
>  		return ret;
>  
>  	tmp &= ~SDHCI_CDNS_HRS04_WR;
> -	writel(tmp, reg);
> +	priv->priv_writel(priv, tmp, reg);
>  
>  	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS04_ACK),
>  				 0, 10);
> @@ -191,7 +198,7 @@ static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
>  	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
>  	tmp &= ~SDHCI_CDNS_HRS06_MODE;
>  	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_MODE, mode);
> -	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
> +	priv->priv_writel(priv, tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
>  }
>  
>  static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
> @@ -223,7 +230,7 @@ static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
>  	 */
>  	for (i = 0; i < 2; i++) {
>  		tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
> -		writel(tmp, reg);
> +		priv->priv_writel(priv, tmp, reg);
>  
>  		ret = readl_poll_timeout(reg, tmp,
>  					 !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
> @@ -386,6 +393,7 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
>  	priv->nr_phy_params = nr_phy_params;
>  	priv->hrs_addr = host->ioaddr;
>  	priv->enhanced_strobe = false;
> +	priv->priv_writel = cdns_writel;
>  	host->ioaddr += SDHCI_CDNS_SRS_BASE;
>  	host->mmc_host_ops.hs400_enhanced_strobe =
>  				sdhci_cdns_hs400_enhanced_strobe;