ARM: OMAP3+: dpll: optimize noncore dpll locking logic

If the dpll is already locked, code can be optimized
to return much earlier than doing redundent set of lock mode
and wait on idlest.

Cc: Tony Lindgren <tony@atomide.com>
Cc: Jon Hunter <jon-hunter@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Mike Turquette <mturquette@ti.com>
Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>

arch/arm/mach-omap2/dpll3xxx.c

@@ -135,11 +135,20 @@ static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
  */
 static int _omap3_noncore_dpll_lock(struct clk *clk)
 {
+	const struct dpll_data *dd;
 	u8 ai;
-	int r;
+	u8 state = 1;
+	int r = 0;
 
 	pr_debug("clock: locking DPLL %s\n", clk->name);
 
+	dd = clk->dpll_data;
+	state <<= __ffs(dd->idlest_mask);
+
+	/* Check if already locked */
+	if ((__raw_readl(dd->idlest_reg) & dd->idlest_mask) == state)
+		goto done;
+
 	ai = omap3_dpll_autoidle_read(clk);
 
 	if (ai)
@@ -152,6 +161,7 @@ static int _omap3_noncore_dpll_lock(struct clk *clk)
 	if (ai)
 		omap3_dpll_allow_idle(clk);
 
+done:
 	return r;
 }