OMAP3 clock: add OMAP3 DPLL autoidle functions

This patch adds support for DPLL autoidle control to the OMAP3 clock
framework.  These functions will be used by the noncore DPLL enable
and disable code - this is because, according to the CDP code, the
DPLL autoidle status must be saved and restored across DPLL
lock/bypass/off transitions.

N.B.: the CORE DPLL (DPLL3) has three autoidle mode options, rather
than just two.  This code currently does not support the third option,
low-power bypass autoidle.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/clock34xx.c

@@ -37,6 +37,10 @@
 #include "cm.h"
 #include "cm-regbits-34xx.h"
 
+/* CM_AUTOIDLE_PLL*.AUTO_* bit values */
+#define DPLL_AUTOIDLE_DISABLE			0x0
+#define DPLL_AUTOIDLE_LOW_POWER_STOP		0x1
+
 /* CM_CLKEN_PLL*.EN* bit values */
 #define DPLL_LOCKED		0x7
 
@@ -53,6 +57,81 @@ static void omap3_dpll_recalc(struct clk *clk)
 	propagate_rate(clk);
 }
 
+/**
+ * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
+ * @clk: struct clk * of the DPLL to read
+ *
+ * Return the DPLL's autoidle bits, shifted down to bit 0.  Returns
+ * -EINVAL if passed a null pointer or if the struct clk does not
+ * appear to refer to a DPLL.
+ */
+static u32 omap3_dpll_autoidle_read(struct clk *clk)
+{
+	const struct dpll_data *dd;
+	u32 v;
+
+	if (!clk || !clk->dpll_data)
+		return -EINVAL;
+
+	dd = clk->dpll_data;
+
+	v = cm_read_reg(dd->autoidle_reg);
+	v &= dd->autoidle_mask;
+	v >>= __ffs(dd->autoidle_mask);
+
+	return v;
+}
+
+/**
+ * omap3_dpll_allow_idle - enable DPLL autoidle bits
+ * @clk: struct clk * of the DPLL to operate on
+ *
+ * Enable DPLL automatic idle control.  This automatic idle mode
+ * switching takes effect only when the DPLL is locked, at least on
+ * OMAP3430.  The DPLL will enter low-power stop when its downstream
+ * clocks are gated.  No return value.
+ */
+static void omap3_dpll_allow_idle(struct clk *clk)
+{
+	const struct dpll_data *dd;
+
+	if (!clk || !clk->dpll_data)
+		return;
+
+	dd = clk->dpll_data;
+
+	/*
+	 * REVISIT: CORE DPLL can optionally enter low-power bypass
+	 * by writing 0x5 instead of 0x1.  Add some mechanism to
+	 * optionally enter this mode.
+	 */
+	cm_rmw_reg_bits(dd->autoidle_mask,
+			DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask),
+			dd->autoidle_reg);
+}
+
+/**
+ * omap3_dpll_deny_idle - prevent DPLL from automatically idling
+ * @clk: struct clk * of the DPLL to operate on
+ *
+ * Disable DPLL automatic idle control.  No return value.
+ */
+static void omap3_dpll_deny_idle(struct clk *clk)
+{
+	const struct dpll_data *dd;
+
+	if (!clk || !clk->dpll_data)
+		return;
+
+	dd = clk->dpll_data;
+
+	cm_rmw_reg_bits(dd->autoidle_mask,
+ 			DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask),
+			dd->autoidle_reg);
+}
+
+
+
 /**
  * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
  * @clk: DPLL output struct clk

arch/arm/mach-omap2/clock34xx.h

@@ -29,6 +29,9 @@
 
 static void omap3_dpll_recalc(struct clk *clk);
 static void omap3_clkoutx2_recalc(struct clk *clk);
+static void omap3_dpll_allow_idle(struct clk *clk);
+static void omap3_dpll_deny_idle(struct clk *clk);
+static u32 omap3_dpll_autoidle_read(struct clk *clk);
 
 /*
  * DPLL1 supplies clock to the MPU.
@@ -254,6 +257,8 @@ static const struct dpll_data dpll1_dd = {
 	.auto_recal_bit	= OMAP3430_EN_MPU_DPLL_DRIFTGUARD_SHIFT,
 	.recal_en_bit	= OMAP3430_MPU_DPLL_RECAL_EN_SHIFT,
 	.recal_st_bit	= OMAP3430_MPU_DPLL_ST_SHIFT,
+	.autoidle_reg	= OMAP_CM_REGADDR(MPU_MOD, OMAP3430_CM_AUTOIDLE_PLL),
+	.autoidle_mask	= OMAP3430_AUTO_MPU_DPLL_MASK,
 };
 
 static struct clk dpll1_ck = {
@@ -311,6 +316,9 @@ static const struct dpll_data dpll2_dd = {
 	.auto_recal_bit	= OMAP3430_EN_IVA2_DPLL_DRIFTGUARD_SHIFT,
 	.recal_en_bit	= OMAP3430_PRM_IRQENABLE_MPU_IVA2_DPLL_RECAL_EN_SHIFT,
 	.recal_st_bit	= OMAP3430_PRM_IRQSTATUS_MPU_IVA2_DPLL_ST_SHIFT,
+	.autoidle_reg	= OMAP_CM_REGADDR(OMAP3430_IVA2_MOD, OMAP3430_CM_AUTOIDLE_PLL),
+	.autoidle_mask	= OMAP3430_AUTO_IVA2_DPLL_MASK,
+
 };
 
 static struct clk dpll2_ck = {
@@ -355,6 +363,8 @@ static const struct dpll_data dpll3_dd = {
 	.auto_recal_bit	= OMAP3430_EN_CORE_DPLL_DRIFTGUARD_SHIFT,
 	.recal_en_bit	= OMAP3430_CORE_DPLL_RECAL_EN_SHIFT,
 	.recal_st_bit	= OMAP3430_CORE_DPLL_ST_SHIFT,
+	.autoidle_reg	= OMAP_CM_REGADDR(PLL_MOD, CM_AUTOIDLE),
+	.autoidle_mask	= OMAP3430_AUTO_CORE_DPLL_MASK,
 };
 
 static struct clk dpll3_ck = {
@@ -527,6 +537,8 @@ static const struct dpll_data dpll4_dd = {
 	.auto_recal_bit	= OMAP3430_EN_PERIPH_DPLL_DRIFTGUARD_SHIFT,
 	.recal_en_bit	= OMAP3430_PERIPH_DPLL_RECAL_EN_SHIFT,
 	.recal_st_bit	= OMAP3430_PERIPH_DPLL_ST_SHIFT,
+	.autoidle_reg	= OMAP_CM_REGADDR(PLL_MOD, CM_AUTOIDLE),
+	.autoidle_mask	= OMAP3430_AUTO_PERIPH_DPLL_MASK,
 };
 
 static struct clk dpll4_ck = {
@@ -818,6 +830,8 @@ static const struct dpll_data dpll5_dd = {
 	.auto_recal_bit	= OMAP3430ES2_EN_PERIPH2_DPLL_DRIFTGUARD_SHIFT,
 	.recal_en_bit	= OMAP3430ES2_SND_PERIPH_DPLL_RECAL_EN_SHIFT,
 	.recal_st_bit	= OMAP3430ES2_SND_PERIPH_DPLL_ST_SHIFT,
+	.autoidle_reg	= OMAP_CM_REGADDR(PLL_MOD, OMAP3430ES2_CM_AUTOIDLE2_PLL),
+	.autoidle_mask	= OMAP3430ES2_AUTO_PERIPH2_DPLL_MASK,
 };
 
 static struct clk dpll5_ck = {

arch/arm/mach-omap2/cm-regbits-34xx.h

@@ -423,6 +423,10 @@
 #define OMAP3430_AUTO_CORE_DPLL_SHIFT			0
 #define OMAP3430_AUTO_CORE_DPLL_MASK			(0x7 << 0)
 
+/* CM_AUTOIDLE2_PLL */
+#define OMAP3430ES2_AUTO_PERIPH2_DPLL_SHIFT		0
+#define OMAP3430ES2_AUTO_PERIPH2_DPLL_MASK		(0x7 << 0)
+
 /* CM_CLKSEL1_PLL */
 /* Note that OMAP3430_CORE_DPLL_CLKOUT_DIV_MASK was (0x3 << 27) on 3430ES1 */
 #define OMAP3430_CORE_DPLL_CLKOUT_DIV_SHIFT		27

arch/arm/mach-omap2/cm.h

@@ -112,6 +112,7 @@ static u32 __attribute__((unused)) cm_rmw_reg_bits(u32 mask, u32 bits, void __io
 #define OMAP3430ES2_CM_FCLKEN3				0x0008
 #define OMAP3430_CM_IDLEST_PLL				CM_IDLEST2
 #define OMAP3430_CM_AUTOIDLE_PLL			CM_AUTOIDLE2
+#define OMAP3430ES2_CM_AUTOIDLE2_PLL			CM_AUTOIDLE2
 #define OMAP3430_CM_CLKSEL1				CM_CLKSEL
 #define OMAP3430_CM_CLKSEL1_PLL				CM_CLKSEL
 #define OMAP3430_CM_CLKSEL2_PLL				CM_CLKSEL2

include/asm-arm/arch-omap/clock.h

@@ -41,6 +41,8 @@ struct dpll_data {
 	u8			auto_recal_bit;
 	u8			recal_en_bit;
 	u8			recal_st_bit;
+	void __iomem		*autoidle_reg;
+	u32			autoidle_mask;
 #  endif
 };