ARC: HSDK: Fixup DW SDIO CIU frequency to 50000000Hz

[people/ms/u-boot.git] / board / synopsys / hsdk / hsdk.c

diff --git a/board/synopsys/hsdk/hsdk.c b/board/synopsys/hsdk/hsdk.c
index 7b562556e6bcd9469185fbaa5182752f10a36939..7641978a7b13d7b5bd17cccca06b640499c8b49e 100644 (file)
--- a/board/synopsys/hsdk/hsdk.c
+++ b/board/synopsys/hsdk/hsdk.c
@@ -26,6 +26,10 @@ int board_early_init_f(void)
        return 0;
 }
 
+#define SDIO_BASE              (ARC_PERIPHERAL_BASE + 0xA000)
+#define SDIO_UHS_REG_EXT       (SDIO_BASE + 0x108)
+#define SDIO_UHS_REG_EXT_DIV_2 (2 << 30)
+
 int board_mmc_init(bd_t *bis)
 {
        struct dwmci_host *host = NULL;
@@ -36,12 +40,18 @@ int board_mmc_init(bd_t *bis)
                return 1;
        }
 
+       /*
+        * Switch SDIO external ciu clock divider from default div-by-8 to
+        * minimum possible div-by-2.
+        */
+       writel(SDIO_UHS_REG_EXT_DIV_2, (void __iomem *) SDIO_UHS_REG_EXT);
+
        memset(host, 0, sizeof(struct dwmci_host));
        host->name = "Synopsys Mobile storage";
        host->ioaddr = (void *)ARC_DWMMC_BASE;
        host->buswidth = 4;
        host->dev_index = 0;
-       host->bus_hz = 100000000;
+       host->bus_hz = 50000000;
 
        add_dwmci(host, host->bus_hz / 2, 400000);