mmc: sdhci: add sdma_boundary member to struct sdhci_host

This patch adds sdma_boundary member to struct sdhci_host to give more
flexibility to drivers to control the sdma boundary buffer value and
also to fix issue on some sdhci controllers which are broken when
HOST SDMA Buffer Boundary is programmed in Block Size Register (0x04)
when using ADMA. Qualcomm sdhci controller is one of such type, writing
to this bits is un-supported.

Default value of sdma_boundary is set to SDHCI_DEFAULT_BOUNDARY_ARG.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

@@ -897,8 +897,8 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 	sdhci_set_transfer_irqs(host);
 
 	/* Set the DMA boundary value and block size */
-	sdhci_writew(host, SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG,
-		data->blksz), SDHCI_BLOCK_SIZE);
+	sdhci_writew(host, SDHCI_MAKE_BLKSZ(host->sdma_boundary, data->blksz),
+		     SDHCI_BLOCK_SIZE);
 	sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
 }
 
@@ -2037,6 +2037,7 @@ static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode)
 	struct mmc_command cmd = {};
 	struct mmc_request mrq = {};
 	unsigned long flags;
+	u32 b = host->sdma_boundary;
 
 	spin_lock_irqsave(&host->lock, flags);
 
@@ -2052,9 +2053,9 @@ static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode)
 	 */
 	if (cmd.opcode == MMC_SEND_TUNING_BLOCK_HS200 &&
 	    mmc->ios.bus_width == MMC_BUS_WIDTH_8)
-		sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 128), SDHCI_BLOCK_SIZE);
+		sdhci_writew(host, SDHCI_MAKE_BLKSZ(b, 128), SDHCI_BLOCK_SIZE);
 	else
-		sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64), SDHCI_BLOCK_SIZE);
+		sdhci_writew(host, SDHCI_MAKE_BLKSZ(b, 64), SDHCI_BLOCK_SIZE);
 
 	/*
 	 * The tuning block is sent by the card to the host controller.
@@ -2995,7 +2996,7 @@ void sdhci_cqe_enable(struct mmc_host *mmc)
 		ctrl |= SDHCI_CTRL_ADMA32;
 	sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
 
-	sdhci_writew(host, SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG, 512),
+	sdhci_writew(host, SDHCI_MAKE_BLKSZ(host->sdma_boundary, 512),
 		     SDHCI_BLOCK_SIZE);
 
 	/* Set maximum timeout */
@@ -3116,6 +3117,8 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev,
 
 	host->tuning_delay = -1;
 
+	host->sdma_boundary = SDHCI_DEFAULT_BOUNDARY_ARG;
+
 	return host;
 }
 

drivers/mmc/host/sdhci.h

@@ -541,6 +541,9 @@ struct sdhci_host {
 	/* Delay (ms) between tuning commands */
 	int			tuning_delay;
 
+	/* Host SDMA buffer boundary. */
+	u32			sdma_boundary;
+
 	unsigned long private[0] ____cacheline_aligned;
 };