mmc: esdhc: Fix DMA_MASK to not break mx25 DMA access

Patch to not set reserved bits in i.MX25 PROCTL register.  DMA stops
working if those bits get set.
Signed-off-by: Wilson Callan <wilson.callan@savantsystems.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -299,6 +299,8 @@ static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg)
 
 static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg)
 {
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct pltfm_imx_data *imx_data = pltfm_host->priv;
 	u32 new_val;
 
 	switch (reg) {
@@ -315,8 +317,11 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg)
 				SDHCI_CTRL_D3CD);
 		/* ensure the endianess */
 		new_val |= ESDHC_HOST_CONTROL_LE;
-		/* DMA mode bits are shifted */
-		new_val |= (val & SDHCI_CTRL_DMA_MASK) << 5;
+		/* bits 8&9 are reserved on mx25 */
+		if (!is_imx25_esdhc(imx_data)) {
+			/* DMA mode bits are shifted */
+			new_val |= (val & SDHCI_CTRL_DMA_MASK) << 5;
+		}
 
 		esdhc_clrset_le(host, 0xffff, new_val, reg);
 		return;