[ARM] omap: provide a NULL clock operations structure

... and use it for clocks which are ALWAYS_ENABLED.  These clocks
use a non-NULL enable_reg pointer for other purposes (such as
selecting clock rates.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 24 insertions, 3 deletions

diff --git a/arch/arm/plat-omap/clock.c b/arch/arm/plat-omap/clock.c
index be6aab9c6834..529c4a9f012e 100644
--- a/arch/arm/plat-omap/clock.c
+++ b/arch/arm/plat-omap/clock.c
@@ -358,6 +358,23 @@ void clk_enable_init_clocks(void)
 }
 EXPORT_SYMBOL(clk_enable_init_clocks);
 
+/*
+ * Low level helpers
+ */
+static int clkll_enable_null(struct clk *clk)
+{
+        return 0;
+}
+
+static void clkll_disable_null(struct clk *clk)
+{
+}
+
+const struct clkops clkops_null = {
+        .enable         = clkll_enable_null,
+        .disable        = clkll_disable_null,
+};
+
 #ifdef CONFIG_CPU_FREQ
 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 {
@@ -383,8 +400,10 @@ static int __init clk_disable_unused(void)
         unsigned long flags;
 
         list_for_each_entry(ck, &clocks, node) {
-                if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
-                        ck->enable_reg == 0)
+                if (ck->ops == &clkops_null)
+                        continue;
+
+                if (ck->usecount > 0 || ck->enable_reg == 0)
                         continue;
 
                 spin_lock_irqsave(&clockfw_lock, flags);
diff --git a/arch/arm/plat-omap/include/mach/clock.h b/arch/arm/plat-omap/include/mach/clock.h
index 4fe5084e8cc2..c1e484463ed5 100644
--- a/arch/arm/plat-omap/include/mach/clock.h
+++ b/arch/arm/plat-omap/include/mach/clock.h
@@ -125,11 +125,13 @@ extern void clk_deny_idle(struct clk *clk);
 extern int clk_get_usecount(struct clk *clk);
 extern void clk_enable_init_clocks(void);
 
+extern const struct clkops clkops_null;
+
 /* Clock flags */
 #define RATE_CKCTL              (1 << 0)        /* Main fixed ratio clocks */
 #define RATE_FIXED              (1 << 1)        /* Fixed clock rate */
 #define RATE_PROPAGATES         (1 << 2)        /* Program children too */
-#define ALWAYS_ENABLED          (1 << 4)        /* Clock cannot be disabled */
+/* bits 3-4 are free */
 #define ENABLE_REG_32BIT        (1 << 5)        /* Use 32-bit access */
 #define VIRTUAL_IO_ADDRESS      (1 << 6)        /* Clock in virtual address */
 #define CLOCK_IDLE_CONTROL      (1 << 7)