mmc: sdhci: add adma_table_cnt member to struct sdhci_host

This patch adds adma_table_cnt member to struct sdhci_host to give more
flexibility to drivers to control the ADMA table count.

Default value of adma_table_cnt is set to (SDHCI_MAX_SEGS * 2 + 1).

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

@@ -3324,6 +3324,13 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev,
 
 	host->sdma_boundary = SDHCI_DEFAULT_BOUNDARY_ARG;
 
+	/*
+	 * The DMA table descriptor count is calculated as the maximum
+	 * number of segments times 2, to allow for an alignment
+	 * descriptor for each segment, plus 1 for a nop end descriptor.
+	 */
+	host->adma_table_cnt = SDHCI_MAX_SEGS * 2 + 1;
+
 	return host;
 }
 
@@ -3569,18 +3576,12 @@ int sdhci_setup_host(struct sdhci_host *host)
 		dma_addr_t dma;
 		void *buf;
 
-		/*
-		 * The DMA descriptor table size is calculated as the maximum
-		 * number of segments times 2, to allow for an alignment
-		 * descriptor for each segment, plus 1 for a nop end descriptor,
-		 * all multipled by the descriptor size.
-		 */
 		if (host->flags & SDHCI_USE_64_BIT_DMA) {
-			host->adma_table_sz = (SDHCI_MAX_SEGS * 2 + 1) *
+			host->adma_table_sz = host->adma_table_cnt *
 					      SDHCI_ADMA2_64_DESC_SZ;
 			host->desc_sz = SDHCI_ADMA2_64_DESC_SZ;
 		} else {
-			host->adma_table_sz = (SDHCI_MAX_SEGS * 2 + 1) *
+			host->adma_table_sz = host->adma_table_cnt *
 					      SDHCI_ADMA2_32_DESC_SZ;
 			host->desc_sz = SDHCI_ADMA2_32_DESC_SZ;
 		}

drivers/mmc/host/sdhci.h

@@ -564,6 +564,9 @@ struct sdhci_host {
 	/* Host SDMA buffer boundary. */
 	u32			sdma_boundary;
 
+	/* Host ADMA table count */
+	u32			adma_table_cnt;
+
 	u64			data_timeout;
 
 	unsigned long private[0] ____cacheline_aligned;