ARM: OMAP2xxx: clock: add APLL rate recalculation functions

OMAP2420 and OMAP2430 chips each have two on-chip APLLs.  When locked,
one APLL generates a 96 MHz rate; the other, a 54 MHz rate.
Previously we treated these clocks as fixed-rate clocks at the locked
rates, but this isn't quite right.  The locked rate should be returned
when the APLL is locked, and a zero rate should be returned when the
APLL is stopped.  This patch adds the infrastructure that will be used
by the CCF changes.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Mike Turquette <mturquette@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>

arch/arm/mach-omap2/clkt2xxx_apll.c

@@ -38,6 +38,27 @@
 
 /* Private functions */
 
+#ifdef CONFIG_COMMON_CLK
+/**
+ * omap2xxx_clk_apll_locked - is the APLL locked?
+ * @hw: struct clk_hw * of the APLL to check
+ *
+ * If the APLL IP block referred to by @hw indicates that it's locked,
+ * return true; otherwise, return false.
+ */
+static bool omap2xxx_clk_apll_locked(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	u32 r, apll_mask;
+
+	apll_mask = EN_APLL_LOCKED << clk->enable_bit;
+
+	r = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKEN);
+
+	return ((r & apll_mask) == apll_mask) ? true : false;
+}
+#endif
+
 #ifdef CONFIG_COMMON_CLK
 int omap2_clk_apll96_enable(struct clk_hw *hw)
 #else
@@ -110,6 +131,20 @@ static void _apll54_disable(struct clk *clk)
 	omap2xxx_cm_apll54_disable();
 }
 
+#ifdef CONFIG_COMMON_CLK
+unsigned long omap2_clk_apll54_recalc(struct clk_hw *hw,
+				      unsigned long parent_rate)
+{
+	return (omap2xxx_clk_apll_locked(hw)) ? 54000000 : 0;
+}
+
+unsigned long omap2_clk_apll96_recalc(struct clk_hw *hw,
+				      unsigned long parent_rate)
+{
+	return (omap2xxx_clk_apll_locked(hw)) ? 96000000 : 0;
+}
+#endif
+
 /* Public data */
 #ifdef CONFIG_COMMON_CLK
 const struct clk_hw_omap_ops clkhwops_apll54 = {

arch/arm/mach-omap2/clock2xxx.h

@@ -27,6 +27,10 @@ unsigned long omap2_dpllcore_recalc(struct clk_hw *hw,
 int omap2_reprogram_dpllcore(struct clk_hw *clk, unsigned long rate,
 			     unsigned long parent_rate);
 void omap2xxx_clkt_dpllcore_init(struct clk_hw *hw);
+unsigned long omap2_clk_apll54_recalc(struct clk_hw *hw,
+				      unsigned long parent_rate);
+unsigned long omap2_clk_apll96_recalc(struct clk_hw *hw,
+				      unsigned long parent_rate);
 #else
 unsigned long omap2_table_mpu_recalc(struct clk *clk);
 int omap2_select_table_rate(struct clk *clk, unsigned long rate);