mmc: sdhci-cadence: Enable device specific override of writel()

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@amd.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20230410184526.15990-12-blarson@amd.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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;