ARM: 6310/1: mmci: support different FIFO sizes

The Ux500 variant has a 32-word FIFO (TXFIFOEMPTY is asserted when it
has 2 left) and TXFIFOHALFEMPTY is repurposed as TXFIFOBURSTWRITEABLE,
with a burst being defined as 8-words.  Likewise for RX.

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, 19 insertions, 3 deletions

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 9a9aeac50a6c..1932e9cc8f52 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -41,23 +41,35 @@ static unsigned int fmax = 515633;
  * @clkreg: default value for MCICLOCK register
  * @clkreg_enable: enable value for MMCICLOCK register
  * @datalength_bits: number of bits in the MMCIDATALENGTH register
+ * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
+ *            is asserted (likewise for RX)
+ * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY
+ *                is asserted (likewise for RX)
  */
 struct variant_data {
         unsigned int            clkreg;
         unsigned int            clkreg_enable;
         unsigned int            datalength_bits;
+        unsigned int            fifosize;
+        unsigned int            fifohalfsize;
 };
 
 static struct variant_data variant_arm = {
+        .fifosize               = 16 * 4,
+        .fifohalfsize           = 8 * 4,
         .datalength_bits        = 16,
 };
 
 static struct variant_data variant_u300 = {
+        .fifosize               = 16 * 4,
+        .fifohalfsize           = 8 * 4,
         .clkreg_enable          = 1 << 13, /* HWFCEN */
         .datalength_bits        = 16,
 };
 
 static struct variant_data variant_ux500 = {
+        .fifosize               = 30 * 4,
+        .fifohalfsize           = 8 * 4,
         .clkreg                 = MCI_CLK_ENABLE,
         .clkreg_enable          = 1 << 14, /* HWFCEN */
         .datalength_bits        = 24,
@@ -138,6 +150,7 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
 
 static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 {
+        struct variant_data *variant = host->variant;
         unsigned int datactrl, timeout, irqmask;
         unsigned long long clks;
         void __iomem *base;
@@ -173,7 +186,7 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
                  * If we have less than a FIFOSIZE of bytes to transfer,
                  * trigger a PIO interrupt as soon as any data is available.
                  */
-                if (host->size < MCI_FIFOSIZE)
+                if (host->size < variant->fifosize)
                         irqmask |= MCI_RXDATAAVLBLMASK;
         } else {
                 /*
@@ -332,13 +345,15 @@ static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int rema
 
 static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int remain, u32 status)
 {
+        struct variant_data *variant = host->variant;
         void __iomem *base = host->base;
         char *ptr = buffer;
 
         do {
                 unsigned int count, maxcnt;
 
-                maxcnt = status & MCI_TXFIFOEMPTY ? MCI_FIFOSIZE : MCI_FIFOHALFSIZE;
+                maxcnt = status & MCI_TXFIFOEMPTY ?
+                         variant->fifosize : variant->fifohalfsize;
                 count = min(remain, maxcnt);
 
                 writesl(base + MMCIFIFO, ptr, count >> 2);
@@ -362,6 +377,7 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
 {
         struct mmci_host *host = dev_id;
         struct sg_mapping_iter *sg_miter = &host->sg_miter;
+        struct variant_data *variant = host->variant;
         void __iomem *base = host->base;
         unsigned long flags;
         u32 status;
@@ -420,7 +436,7 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
          * If we're nearing the end of the read, switch to
          * "any data available" mode.
          */
-        if (status & MCI_RXACTIVE && host->size < MCI_FIFOSIZE)
+        if (status & MCI_RXACTIVE && host->size < variant->fifosize)
                 writel(MCI_RXDATAAVLBLMASK, base + MMCIMASK1);
 
         /*