2 files changed, 29 insertions, 2 deletions

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 2e6075fdce46..063136d89b42 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -73,6 +73,7 @@ static unsigned int fmax = 515633;
  * @busy_detect: true if busy detection on dat0 is supported
  * @pwrreg_nopower: bits in MMCIPOWER don't controls ext. power supply
  * @explicit_mclk_control: enable explicit mclk control in driver.
+ * @qcom_fifo: enables qcom specific fifo pio read logic.
  */
 struct variant_data {
         unsigned int            clkreg;
@@ -95,6 +96,7 @@ struct variant_data {
         bool                    busy_detect;
         bool                    pwrreg_nopower;
         bool                    explicit_mclk_control;
+        bool                    qcom_fifo;
 };
 
 static struct variant_data variant_arm = {
@@ -992,15 +994,34 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
         }
 }
 
+static int mmci_get_rx_fifocnt(struct mmci_host *host, u32 status, int remain)
+{
+        return remain - (readl(host->base + MMCIFIFOCNT) << 2);
+}
+
+static int mmci_qcom_get_rx_fifocnt(struct mmci_host *host, u32 status, int r)
+{
+        /*
+         * on qcom SDCC4 only 8 words are used in each burst so only 8 addresses
+         * from the fifo range should be used
+         */
+        if (status & MCI_RXFIFOHALFFULL)
+                return host->variant->fifohalfsize;
+        else if (status & MCI_RXDATAAVLBL)
+                return 4;
+
+        return 0;
+}
+
 static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain)
 {
         void __iomem *base = host->base;
         char *ptr = buffer;
-        u32 status;
+        u32 status = readl(host->base + MMCISTATUS);
         int host_remain = host->size;
 
         do {
-                int count = host_remain - (readl(base + MMCIFIFOCNT) << 2);
+                int count = host->get_rx_fifocnt(host, status, host_remain);
 
                 if (count > remain)
                         count = remain;
@@ -1489,6 +1510,11 @@ static int mmci_probe(struct amba_device *dev,
         if (ret)
                 goto host_free;
 
+        if (variant->qcom_fifo)
+                host->get_rx_fifocnt = mmci_qcom_get_rx_fifocnt;
+        else
+                host->get_rx_fifocnt = mmci_get_rx_fifocnt;
+
         host->plat = plat;
         host->variant = variant;
         host->mclk = clk_get_rate(host->clk);
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index ef346170b241..a1f5e4f49e2a 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -229,6 +229,7 @@ struct mmci_host {
         /* pio stuff */
         struct sg_mapping_iter  sg_miter;
         unsigned int            size;
+        int (*get_rx_fifocnt)(struct mmci_host *h, u32 status, int remain);
 
 #ifdef CONFIG_DMA_ENGINE
         /* DMA stuff */