ARM: tegra: powergate: Allow calling power up when already powered

Allow calling tegra_powergate_sequence_power_up on a partition
that is already powered.  Reset the partition, and return success
with the clock enabled.

Change-Id: I776c6a84091f0bb8faca22d87b3fabf0cfede564
Signed-off-by: Colin Cross <ccross@android.com>

diff --git a/arch/arm/mach-tegra/powergate.c b/arch/arm/mach-tegra/powergate.c
index 583a7e3751ac0c4a10e1f61442f0c87f3d366b1e..3d75e1e2d4a1464d2e56c7aa12444ad996e483b1 100644 (file)
--- a/arch/arm/mach-tegra/powergate.c
+++ b/arch/arm/mach-tegra/powergate.c
@@ -123,11 +123,34 @@ int tegra_powergate_remove_clamping(int id)
        return 0;
 }
 
+/* Must be called with clk disabled, and returns with clk enabled */
+static int tegra_powergate_reset_module(struct clk *clk)
+{
+       int ret;
+
+       tegra_periph_reset_assert(clk);
+
+       udelay(10);
+
+       ret = clk_enable(clk);
+       if (ret)
+               return ret;
+
+       udelay(10);
+
+       tegra_periph_reset_deassert(clk);
+
+       return 0;
+}
+
 /* Must be called with clk disabled, and returns with clk enabled */
 int tegra_powergate_sequence_power_up(int id, struct clk *clk)
 {
        int ret;
 
+       if (tegra_powergate_is_powered(id))
+               return tegra_powergate_reset_module(clk);
+
        tegra_periph_reset_assert(clk);
 
        ret = tegra_powergate_power_on(id);