ARM: OMAP: Add support for forcing osc_ck on

Some boards might use the oscillator clock for powering
external peripherals. Add support for making sure osc_ck
stays active even when trying to go to sleep.

Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

2 files changed, 19 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index 302d5a796340..737aca4cff13 100644
--- a/arch/arm/mach-omap2/clock.c
+++ b/arch/arm/mach-omap2/clock.c
@@ -81,6 +81,14 @@ static void omap2_propagate_rate(struct clk * clk)
         propagate_rate(clk);
 }
 
+static void omap2_set_osc_ck(int enable)
+{
+        if (enable)
+                PRCM_CLKSRC_CTRL &= ~(0x3 << 3);
+        else
+                PRCM_CLKSRC_CTRL |= 0x3 << 3;
+}
+
 /* Enable an APLL if off */
 static void omap2_clk_fixed_enable(struct clk *clk)
 {
@@ -121,6 +129,11 @@ static int _omap2_clk_enable(struct clk * clk)
         if (clk->flags & ALWAYS_ENABLED)
                 return 0;
 
+        if (unlikely(clk == &osc_ck)) {
+                omap2_set_osc_ck(1);
+                return 0;
+        }
+
         if (unlikely(clk->enable_reg == 0)) {
                 printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
                        clk->name);
@@ -158,6 +171,11 @@ static void _omap2_clk_disable(struct clk *clk)
 {
         u32 regval32;
 
+        if (unlikely(clk == &osc_ck)) {
+                omap2_set_osc_ck(0);
+                return;
+        }
+
         if (clk->enable_reg == 0)
                 return;
 
diff --git a/arch/arm/mach-omap2/clock.h b/arch/arm/mach-omap2/clock.h
index 2781dfbc5164..223152d9663f 100644
--- a/arch/arm/mach-omap2/clock.h
+++ b/arch/arm/mach-omap2/clock.h
@@ -560,7 +560,7 @@ static struct clk osc_ck = {		/* (*12, *13, 19.2, *26, 38.4)MHz */
         .name           = "osc_ck",
         .rate           = 26000000,             /* fixed up in clock init */
         .flags          = CLOCK_IN_OMAP242X | CLOCK_IN_OMAP243X |
-                                RATE_FIXED | ALWAYS_ENABLED | RATE_PROPAGATES,
+                                RATE_FIXED | RATE_PROPAGATES,
 };
 
 /* With out modem likely 12MHz, with modem likely 13MHz */