ARM: 6246/1: mmci: support larger MMCIDATALENGTH register

The Ux500 variant has a 24-bit MMCIDATALENGTH register, as opposed to
the 16-bit one on the ARM version.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 379af904bf6..7edae83603d 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -40,22 +40,27 @@ static unsigned int fmax = 515633;
  * struct variant_data - MMCI variant-specific quirks
  * @clkreg: default value for MCICLOCK register
  * @clkreg_enable: enable value for MMCICLOCK register
+ * @datalength_bits: number of bits in the MMCIDATALENGTH register
  */
 struct variant_data {
         unsigned int            clkreg;
         unsigned int            clkreg_enable;
+        unsigned int            datalength_bits;
 };
 
 static struct variant_data variant_arm = {
+        .datalength_bits        = 16,
 };
 
 static struct variant_data variant_u300 = {
         .clkreg_enable          = 1 << 13, /* HWFCEN */
+        .datalength_bits        = 16,
 };
 
 static struct variant_data variant_ux500 = {
         .clkreg                 = MCI_CLK_ENABLE,
         .clkreg_enable          = 1 << 14, /* HWFCEN */
+        .datalength_bits        = 24,
 };
 /*
  * This must be called with host->lock held
@@ -699,10 +704,11 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id)
         mmc->max_phys_segs = NR_SG;
 
         /*
-         * Since we only have a 16-bit data length register, we must
-         * ensure that we don't exceed 2^16-1 bytes in a single request.
+         * Since only a certain number of bits are valid in the data length
+         * register, we must ensure that we don't exceed 2^num-1 bytes in a
+         * single request.
          */
-        mmc->max_req_size = 65535;
+        mmc->max_req_size = (1 << variant->datalength_bits) - 1;
 
         /*
          * Set the maximum segment size.  Since we aren't doing DMA