4 files changed, 36 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/clock.c b/arch/arm/mach-tegra/clock.c
index f1f9c6d36bd2..165aa9c748f6 100644
--- a/arch/arm/mach-tegra/clock.c
+++ b/arch/arm/mach-tegra/clock.c
@@ -390,6 +390,20 @@ void __init tegra_init_clock(void)
         tegra2_init_clocks();
 }
 
+/*
+ * The SDMMC controllers have extra bits in the clock source register that
+ * adjust the delay between the clock and data to compenstate for delays
+ * on the PCB.
+ */
+void tegra_sdmmc_tap_delay(struct clk *c, int delay)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&c->spinlock, flags);
+        tegra2_sdmmc_tap_delay(c, delay);
+        spin_unlock_irqrestore(&c->spinlock, flags);
+}
+
 #ifdef CONFIG_DEBUG_FS
 
 static int __clk_lock_all_spinlocks(void)
diff --git a/arch/arm/mach-tegra/clock.h b/arch/arm/mach-tegra/clock.h
index ebe6ea8b0575..688316abc64e 100644
--- a/arch/arm/mach-tegra/clock.h
+++ b/arch/arm/mach-tegra/clock.h
@@ -155,5 +155,6 @@ int clk_reparent(struct clk *c, struct clk *parent);
 void tegra_clk_init_from_table(struct tegra_clk_init_table *table);
 unsigned long clk_get_rate_locked(struct clk *c);
 int clk_set_rate_locked(struct clk *c, unsigned long rate);
+void tegra2_sdmmc_tap_delay(struct clk *c, int delay);
 
 #endif
diff --git a/arch/arm/mach-tegra/include/mach/clk.h b/arch/arm/mach-tegra/include/mach/clk.h
index fa7f9ca1fdbd..c8baf8f80d23 100644
--- a/arch/arm/mach-tegra/include/mach/clk.h
+++ b/arch/arm/mach-tegra/include/mach/clk.h
@@ -26,4 +26,6 @@ void tegra_periph_reset_deassert(struct clk *c);
 void tegra_periph_reset_assert(struct clk *c);
 
 unsigned long clk_get_rate_all_locked(struct clk *c);
+void tegra_sdmmc_tap_delay(struct clk *c, int delay);
+
 #endif
diff --git a/arch/arm/mach-tegra/tegra2_clocks.c b/arch/arm/mach-tegra/tegra2_clocks.c
index 7f7068714049..b85d2c75fb3c 100644
--- a/arch/arm/mach-tegra/tegra2_clocks.c
+++ b/arch/arm/mach-tegra/tegra2_clocks.c
@@ -74,6 +74,10 @@
 #define PERIPH_CLK_SOURCE_DIVU16_MASK   0xFFFF
 #define PERIPH_CLK_SOURCE_DIV_SHIFT     0
 
+#define SDMMC_CLK_INT_FB_SEL            (1 << 23)
+#define SDMMC_CLK_INT_FB_DLY_SHIFT      16
+#define SDMMC_CLK_INT_FB_DLY_MASK       (0xF << SDMMC_CLK_INT_FB_DLY_SHIFT)
+
 #define PLL_BASE                        0x0
 #define PLL_BASE_BYPASS                 (1<<31)
 #define PLL_BASE_ENABLE                 (1<<30)
@@ -1052,6 +1056,21 @@ static struct clk_ops tegra_periph_clk_ops = {
         .reset                  = &tegra2_periph_clk_reset,
 };
 
+/* The SDMMC controllers have extra bits in the clock source register that
+ * adjust the delay between the clock and data to compenstate for delays
+ * on the PCB. */
+void tegra2_sdmmc_tap_delay(struct clk *c, int delay)
+{
+        u32 reg;
+
+        delay = clamp(delay, 0, 15);
+        reg = clk_readl(c->reg);
+        reg &= ~SDMMC_CLK_INT_FB_DLY_MASK;
+        reg |= SDMMC_CLK_INT_FB_SEL;
+        reg |= delay << SDMMC_CLK_INT_FB_DLY_SHIFT;
+        clk_writel(reg, c->reg);
+}
+
 /* External memory controller clock ops */
 static void tegra2_emc_clk_init(struct clk *c)
 {