ARM: OMAP3+: dpll: Configure autoidle mode only if it's supported

The current DPLL code enables and disables autoidle features
without checking whether the autoidle register is available.
Fix this by putting a check for the existence of the autoidle
register in the DPLL data.

With such a check in place, for DPLLs which do not support this
feature, simply skipping the autoidle_reg entry in the DPLL data
is sufficient.

Signed-off-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>

arch/arm/mach-omap2/dpll3xxx.c

@@ -142,7 +142,8 @@ static int _omap3_noncore_dpll_lock(struct clk *clk)
 
 	ai = omap3_dpll_autoidle_read(clk);
 
-	omap3_dpll_deny_idle(clk);
+	if (ai)
+		omap3_dpll_deny_idle(clk);
 
 	_omap3_dpll_write_clken(clk, DPLL_LOCKED);
 
@@ -186,8 +187,6 @@ static int _omap3_noncore_dpll_bypass(struct clk *clk)
 
 	if (ai)
 		omap3_dpll_allow_idle(clk);
-	else
-		omap3_dpll_deny_idle(clk);
 
 	return r;
 }
@@ -216,8 +215,6 @@ static int _omap3_noncore_dpll_stop(struct clk *clk)
 
 	if (ai)
 		omap3_dpll_allow_idle(clk);
-	else
-		omap3_dpll_deny_idle(clk);
 
 	return 0;
 }
@@ -519,6 +516,9 @@ u32 omap3_dpll_autoidle_read(struct clk *clk)
 
 	dd = clk->dpll_data;
 
+	if (!dd->autoidle_reg)
+		return -EINVAL;
+
 	v = __raw_readl(dd->autoidle_reg);
 	v &= dd->autoidle_mask;
 	v >>= __ffs(dd->autoidle_mask);
@@ -545,6 +545,12 @@ void omap3_dpll_allow_idle(struct clk *clk)
 
 	dd = clk->dpll_data;
 
+	if (!dd->autoidle_reg) {
+		pr_debug("clock: DPLL %s: autoidle not supported\n",
+			clk->name);
+		return;
+	}
+
 	/*
 	 * REVISIT: CORE DPLL can optionally enter low-power bypass
 	 * by writing 0x5 instead of 0x1.  Add some mechanism to
@@ -554,6 +560,7 @@ void omap3_dpll_allow_idle(struct clk *clk)
 	v &= ~dd->autoidle_mask;
 	v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
 	__raw_writel(v, dd->autoidle_reg);
+
 }
 
 /**
@@ -572,6 +579,12 @@ void omap3_dpll_deny_idle(struct clk *clk)
 
 	dd = clk->dpll_data;
 
+	if (!dd->autoidle_reg) {
+		pr_debug("clock: DPLL %s: autoidle not supported\n",
+			clk->name);
+		return;
+	}
+
 	v = __raw_readl(dd->autoidle_reg);
 	v &= ~dd->autoidle_mask;
 	v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);