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>

diff --git a/arch/arm/mach-omap2/dpll3xxx.c b/arch/arm/mach-omap2/dpll3xxx.c
index f0f10beeffe8ec77fe8d77b9a81934e83bd92bb1..c310dc0d40b4d357a72f3fd0c5ca2ce845cfce64 100644 (file)
--- a/arch/arm/mach-omap2/dpll3xxx.c
+++ b/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;
 }