ARM: tegra: clock: Disable clocks left on by bootloader
Colin Cross [Mon, 21 Feb 2011 23:47:24 +0000 (15:47 -0800)]
Iterates through all clocks, disabling any for which the
refcount is 0 but the clock init detected the bootloader
left the clock on.  Can be disabled with command line
tegra_keep_boot_clocks

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

arch/arm/mach-tegra/clock.c

index f8d41ff..48d50d3 100644 (file)
@@ -416,6 +416,51 @@ void tegra_sdmmc_tap_delay(struct clk *c, int delay)
        spin_unlock_irqrestore(&c->spinlock, flags);
 }
 
+static bool tegra_keep_boot_clocks = false;
+static int __init tegra_keep_boot_clocks_setup(char *__unused)
+{
+       tegra_keep_boot_clocks = true;
+       return 1;
+}
+__setup("tegra_keep_boot_clocks", tegra_keep_boot_clocks_setup);
+
+/*
+ * Iterate through all clocks, disabling any for which the refcount is 0
+ * but the clock init detected the bootloader left the clock on.
+ */
+static int __init tegra_init_disable_boot_clocks(void)
+{
+       struct clk *c;
+
+       mutex_lock(&clock_list_lock);
+
+       list_for_each_entry(c, &clocks, node) {
+               spin_lock_irq(&c->spinlock);
+
+               if (c->refcnt == 0 && c->state == ON &&
+                               c->ops && c->ops->disable) {
+                       pr_warn_once("%s clocks left on by bootloader:\n",
+                               tegra_keep_boot_clocks ?
+                                       "Prevented disabling" :
+                                       "Disabling");
+
+                       pr_warn("   %s\n", c->name);
+
+                       if (!tegra_keep_boot_clocks) {
+                               c->ops->disable(c);
+                               c->state = OFF;
+                       }
+               }
+
+               spin_unlock_irq(&c->spinlock);
+       }
+
+       mutex_unlock(&clock_list_lock);
+
+       return 0;
+}
+late_initcall(tegra_init_disable_boot_clocks);
+
 #ifdef CONFIG_DEBUG_FS
 
 static int __clk_lock_all_spinlocks(void)