ARM: 6438/2: mmci: add SDIO support for ST Variants

This adds some minor variant data and trickery to enable SDIO
on the ST Micro variants of MMCI/PL180.

Signed-off-by: Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 36 insertions, 1 deletions

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 976c9d0e8080..0814b88b44d6 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -19,6 +19,7 @@
 #include <linux/highmem.h>
 #include <linux/log2.h>
 #include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
 #include <linux/amba/bus.h>
 #include <linux/clk.h>
 #include <linux/scatterlist.h>
@@ -49,6 +50,7 @@ static unsigned int fmax = 515633;
  *              and will not work at all.
  * @broken_blockend_dma: the MCI_DATABLOCKEND is broken on the hardware when
  *              using DMA.
+ * @sdio: variant supports SDIO
  */
 struct variant_data {
         unsigned int            clkreg;
@@ -58,6 +60,7 @@ struct variant_data {
         unsigned int            fifohalfsize;
         bool                    broken_blockend;
         bool                    broken_blockend_dma;
+        bool                    sdio;
 };
 
 static struct variant_data variant_arm = {
@@ -72,6 +75,7 @@ static struct variant_data variant_u300 = {
         .clkreg_enable          = 1 << 13, /* HWFCEN */
         .datalength_bits        = 16,
         .broken_blockend_dma    = true,
+        .sdio                   = true,
 };
 
 static struct variant_data variant_ux500 = {
@@ -81,6 +85,7 @@ static struct variant_data variant_ux500 = {
         .clkreg_enable          = 1 << 14, /* HWFCEN */
         .datalength_bits        = 24,
         .broken_blockend        = true,
+        .sdio                   = true,
 };
 /*
  * This must be called with host->lock held
@@ -222,6 +227,11 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
                 irqmask = MCI_TXFIFOHALFEMPTYMASK;
         }
 
+        /* The ST Micro variants has a special bit to enable SDIO */
+        if (variant->sdio && host->mmc->card)
+                if (mmc_card_sdio(host->mmc->card))
+                        datactrl |= MCI_ST_DPSM_SDIOEN;
+
         writel(datactrl, base + MMCIDATACTRL);
         writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
         mmci_set_mask1(host, irqmask);
@@ -429,7 +439,32 @@ static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int rem
                          variant->fifosize : variant->fifohalfsize;
                 count = min(remain, maxcnt);
 
-                writesl(base + MMCIFIFO, ptr, count >> 2);
+                /*
+                 * The ST Micro variant for SDIO transfer sizes
+                 * less then 8 bytes should have clock H/W flow
+                 * control disabled.
+                 */
+                if (variant->sdio &&
+                    mmc_card_sdio(host->mmc->card)) {
+                        if (count < 8)
+                                writel(readl(host->base + MMCICLOCK) &
+                                        ~variant->clkreg_enable,
+                                        host->base + MMCICLOCK);
+                        else
+                                writel(readl(host->base + MMCICLOCK) |
+                                        variant->clkreg_enable,
+                                        host->base + MMCICLOCK);
+                }
+
+                /*
+                 * SDIO especially may want to send something that is
+                 * not divisible by 4 (as opposed to card sectors
+                 * etc), and the FIFO only accept full 32-bit writes.
+                 * So compensate by adding +3 on the count, a single
+                 * byte become a 32bit write, 7 bytes will be two
+                 * 32bit writes etc.
+                 */
+                writesl(base + MMCIFIFO, ptr, (count + 3) >> 2);
 
                 ptr += count;
                 remain -= count;