Merge branch 'omap-clks3' into devel

Conflicts:

	arch/arm/mach-omap2/clock.c

1 files changed, 283 insertions, 216 deletions

diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index ce4d46a4a83..4247a153441 100644
--- a/arch/arm/mach-omap2/clock.c
+++ b/arch/arm/mach-omap2/clock.c
@@ -26,11 +26,10 @@
 
 #include <mach/clock.h>
 #include <mach/clockdomain.h>
-#include <mach/sram.h>
 #include <mach/cpu.h>
 #include <asm/div64.h>
 
-#include "memory.h"
+#include <mach/sdrc.h>
 #include "sdrc.h"
 #include "clock.h"
 #include "prm.h"
@@ -46,7 +45,7 @@
 #define DPLL_MIN_DIVIDER		1
 
 /* Possible error results from _dpll_test_mult */
-#define DPLL_MULT_UNDERFLOW		(1 << 0)
+#define DPLL_MULT_UNDERFLOW		-1
 
 /*
  * Scale factor to mitigate roundoff errors in DPLL rate rounding.
@@ -59,6 +58,16 @@
 #define DPLL_ROUNDING_VAL		((DPLL_SCALE_BASE / 2) * \
 					 (DPLL_SCALE_FACTOR / DPLL_SCALE_BASE))
 
+/* DPLL valid Fint frequency band limits - from 34xx TRM Section 4.7.6.2 */
+#define DPLL_FINT_BAND1_MIN		750000
+#define DPLL_FINT_BAND1_MAX		2100000
+#define DPLL_FINT_BAND2_MIN		7500000
+#define DPLL_FINT_BAND2_MAX		21000000
+
+/* _dpll_test_fint() return codes */
+#define DPLL_FINT_UNDERFLOW		-1
+#define DPLL_FINT_INVALID		-2
+
 u8 cpu_mask;
 
 /*-------------------------------------------------------------------------
@@ -66,6 +75,74 @@ u8 cpu_mask;
  *-------------------------------------------------------------------------*/
 
 /**
+ * _omap2xxx_clk_commit - commit clock parent/rate changes in hardware
+ * @clk: struct clk *
+ *
+ * If @clk has the DELAYED_APP flag set, meaning that parent/rate changes
+ * don't take effect until the VALID_CONFIG bit is written, write the
+ * VALID_CONFIG bit and wait for the write to complete.  No return value.
+ */
+static void _omap2xxx_clk_commit(struct clk *clk)
+{
+	if (!cpu_is_omap24xx())
+		return;
+
+	if (!(clk->flags & DELAYED_APP))
+		return;
+
+	prm_write_mod_reg(OMAP24XX_VALID_CONFIG, OMAP24XX_GR_MOD,
+		OMAP24XX_PRCM_CLKCFG_CTRL_OFFSET);
+	/* OCP barrier */
+	prm_read_mod_reg(OMAP24XX_GR_MOD, OMAP24XX_PRCM_CLKCFG_CTRL_OFFSET);
+}
+
+/*
+ * _dpll_test_fint - test whether an Fint value is valid for the DPLL
+ * @clk: DPLL struct clk to test
+ * @n: divider value (N) to test
+ *
+ * Tests whether a particular divider @n will result in a valid DPLL
+ * internal clock frequency Fint. See the 34xx TRM 4.7.6.2 "DPLL Jitter
+ * Correction".  Returns 0 if OK, -1 if the enclosing loop can terminate
+ * (assuming that it is counting N upwards), or -2 if the enclosing loop
+ * should skip to the next iteration (again assuming N is increasing).
+ */
+static int _dpll_test_fint(struct clk *clk, u8 n)
+{
+	struct dpll_data *dd;
+	long fint;
+	int ret = 0;
+
+	dd = clk->dpll_data;
+
+	/* DPLL divider must result in a valid jitter correction val */
+	fint = clk->parent->rate / (n + 1);
+	if (fint < DPLL_FINT_BAND1_MIN) {
+
+		pr_debug("rejecting n=%d due to Fint failure, "
+			 "lowering max_divider\n", n);
+		dd->max_divider = n;
+		ret = DPLL_FINT_UNDERFLOW;
+
+	} else if (fint > DPLL_FINT_BAND1_MAX &&
+		   fint < DPLL_FINT_BAND2_MIN) {
+
+		pr_debug("rejecting n=%d due to Fint failure\n", n);
+		ret = DPLL_FINT_INVALID;
+
+	} else if (fint > DPLL_FINT_BAND2_MAX) {
+
+		pr_debug("rejecting n=%d due to Fint failure, "
+			 "boosting min_divider\n", n);
+		dd->min_divider = n;
+		ret = DPLL_FINT_INVALID;
+
+	}
+
+	return ret;
+}
+
+/**
  * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
  * @clk: OMAP clock struct ptr to use
  *
@@ -120,7 +197,7 @@ void omap2_init_clksel_parent(struct clk *clk)
 						 clk->name, clks->parent->name,
 						 ((clk->parent) ?
 						  clk->parent->name : "NULL"));
-					clk->parent = clks->parent;
+					clk_reparent(clk, clks->parent);
 				};
 				found = 1;
 			}
@@ -134,25 +211,52 @@ void omap2_init_clksel_parent(struct clk *clk)
 	return;
 }
 
-/* Returns the DPLL rate */
+/**
+ * omap2_get_dpll_rate - returns the current DPLL CLKOUT rate
+ * @clk: struct clk * of a DPLL
+ *
+ * DPLLs can be locked or bypassed - basically, enabled or disabled.
+ * When locked, the DPLL output depends on the M and N values.  When
+ * bypassed, on OMAP2xxx, the output rate is either the 32KiHz clock
+ * or sys_clk.  Bypass rates on OMAP3 depend on the DPLL: DPLLs 1 and
+ * 2 are bypassed with dpll1_fclk and dpll2_fclk respectively
+ * (generated by DPLL3), while DPLL 3, 4, and 5 bypass rates are sys_clk.
+ * Returns the current DPLL CLKOUT rate (*not* CLKOUTX2) if the DPLL is
+ * locked, or the appropriate bypass rate if the DPLL is bypassed, or 0
+ * if the clock @clk is not a DPLL.
+ */
 u32 omap2_get_dpll_rate(struct clk *clk)
 {
 	long long dpll_clk;
-	u32 dpll_mult, dpll_div, dpll;
+	u32 dpll_mult, dpll_div, v;
 	struct dpll_data *dd;
 
 	dd = clk->dpll_data;
-	/* REVISIT: What do we return on error? */
 	if (!dd)
 		return 0;
 
-	dpll = __raw_readl(dd->mult_div1_reg);
-	dpll_mult = dpll & dd->mult_mask;
+	/* Return bypass rate if DPLL is bypassed */
+	v = __raw_readl(dd->control_reg);
+	v &= dd->enable_mask;
+	v >>= __ffs(dd->enable_mask);
+
+	if (cpu_is_omap24xx()) {
+		if (v == OMAP2XXX_EN_DPLL_LPBYPASS ||
+		    v == OMAP2XXX_EN_DPLL_FRBYPASS)
+			return dd->clk_bypass->rate;
+	} else if (cpu_is_omap34xx()) {
+		if (v == OMAP3XXX_EN_DPLL_LPBYPASS ||
+		    v == OMAP3XXX_EN_DPLL_FRBYPASS)
+			return dd->clk_bypass->rate;
+	}
+
+	v = __raw_readl(dd->mult_div1_reg);
+	dpll_mult = v & dd->mult_mask;
 	dpll_mult >>= __ffs(dd->mult_mask);
-	dpll_div = dpll & dd->div1_mask;
+	dpll_div = v & dd->div1_mask;
 	dpll_div >>= __ffs(dd->div1_mask);
 
-	dpll_clk = (long long)clk->parent->rate * dpll_mult;
+	dpll_clk = (long long)dd->clk_ref->rate * dpll_mult;
 	do_div(dpll_clk, dpll_div + 1);
 
 	return dpll_clk;
@@ -162,14 +266,11 @@ u32 omap2_get_dpll_rate(struct clk *clk)
  * Used for clocks that have the same value as the parent clock,
  * divided by some factor
  */
-void omap2_fixed_divisor_recalc(struct clk *clk)
+unsigned long omap2_fixed_divisor_recalc(struct clk *clk)
 {
 	WARN_ON(!clk->fixed_div);
 
-	clk->rate = clk->parent->rate / clk->fixed_div;
-
-	if (clk->flags & RATE_PROPAGATES)
-		propagate_rate(clk);
+	return clk->parent->rate / clk->fixed_div;
 }
 
 /**
@@ -190,11 +291,10 @@ int omap2_wait_clock_ready(void __iomem *reg, u32 mask, const char *name)
 	 * 24xx uses 0 to indicate not ready, and 1 to indicate ready.
 	 * 34xx reverses this, just to keep us on our toes
 	 */
-	if (cpu_mask & (RATE_IN_242X | RATE_IN_243X)) {
+	if (cpu_mask & (RATE_IN_242X | RATE_IN_243X))
 		ena = mask;
-	} else if (cpu_mask & RATE_IN_343X) {
+	else if (cpu_mask & RATE_IN_343X)
 		ena = 0;
-	}
 
 	/* Wait for lock */
 	while (((__raw_readl(reg) & mask) != ena) &&
@@ -228,31 +328,12 @@ static void omap2_clk_wait_ready(struct clk *clk)
 	 * it and pull it into struct clk itself somehow.
 	 */
 	reg = clk->enable_reg;
-	if ((((u32)reg & 0xff) >= CM_FCLKEN1) &&
-	    (((u32)reg & 0xff) <= OMAP24XX_CM_FCLKEN2))
-		other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x10); /* CM_ICLKEN* */
-	else if ((((u32)reg & 0xff) >= CM_ICLKEN1) &&
-		 (((u32)reg & 0xff) <= OMAP24XX_CM_ICLKEN4))
-		other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x00); /* CM_FCLKEN* */
-	else
-		return;
 
-	/* REVISIT: What are the appropriate exclusions for 34XX? */
-	/* No check for DSS or cam clocks */
-	if (cpu_is_omap24xx() && ((u32)reg & 0x0f) == 0) { /* CM_{F,I}CLKEN1 */
-		if (clk->enable_bit == OMAP24XX_EN_DSS2_SHIFT ||
-		    clk->enable_bit == OMAP24XX_EN_DSS1_SHIFT ||
-		    clk->enable_bit == OMAP24XX_EN_CAM_SHIFT)
-			return;
-	}
-
-	/* REVISIT: What are the appropriate exclusions for 34XX? */
-	/* OMAP3: ignore DSS-mod clocks */
-	if (cpu_is_omap34xx() &&
-	    (((u32)reg & ~0xff) == (u32)OMAP_CM_REGADDR(OMAP3430_DSS_MOD, 0) ||
-	     ((((u32)reg & ~0xff) == (u32)OMAP_CM_REGADDR(CORE_MOD, 0)) &&
-	     clk->enable_bit == OMAP3430_EN_SSI_SHIFT)))
-		return;
+	/*
+	 * Convert CM_ICLKEN* <-> CM_FCLKEN*.  This conversion assumes
+	 * it's just a matter of XORing the bits.
+	 */
+	other_reg = (void __iomem *)((u32)reg ^ (CM_FCLKEN ^ CM_ICLKEN));
 
 	/* Check if both functional and interface clocks
 	 * are running. */
@@ -264,18 +345,9 @@ static void omap2_clk_wait_ready(struct clk *clk)
 	omap2_wait_clock_ready(st_reg, bit, clk->name);
 }
 
-/* Enables clock without considering parent dependencies or use count
- * REVISIT: Maybe change this to use clk->enable like on omap1?
- */
-int _omap2_clk_enable(struct clk *clk)
+static int omap2_dflt_clk_enable(struct clk *clk)
 {
-	u32 regval32;
-
-	if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK))
-		return 0;
-
-	if (clk->enable)
-		return clk->enable(clk);
+	u32 v;
 
 	if (unlikely(clk->enable_reg == NULL)) {
 		printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
@@ -283,33 +355,38 @@ int _omap2_clk_enable(struct clk *clk)
 		return 0; /* REVISIT: -EINVAL */
 	}
 
-	regval32 = __raw_readl(clk->enable_reg);
+	v = __raw_readl(clk->enable_reg);
 	if (clk->flags & INVERT_ENABLE)
-		regval32 &= ~(1 << clk->enable_bit);
+		v &= ~(1 << clk->enable_bit);
 	else
-		regval32 |= (1 << clk->enable_bit);
-	__raw_writel(regval32, clk->enable_reg);
-	wmb();
-
-	omap2_clk_wait_ready(clk);
+		v |= (1 << clk->enable_bit);
+	__raw_writel(v, clk->enable_reg);
+	v = __raw_readl(clk->enable_reg); /* OCP barrier */
 
 	return 0;
 }
 
-/* Disables clock without considering parent dependencies or use count */
-void _omap2_clk_disable(struct clk *clk)
+static int omap2_dflt_clk_enable_wait(struct clk *clk)
 {
-	u32 regval32;
-
-	if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK))
-		return;
+	int ret;
 
-	if (clk->disable) {
-		clk->disable(clk);
-		return;
+	if (!clk->enable_reg) {
+		printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
+		       clk->name);
+		return 0; /* REVISIT: -EINVAL */
 	}
 
-	if (clk->enable_reg == NULL) {
+	ret = omap2_dflt_clk_enable(clk);
+	if (ret == 0)
+		omap2_clk_wait_ready(clk);
+	return ret;
+}
+
+static void omap2_dflt_clk_disable(struct clk *clk)
+{
+	u32 v;
+
+	if (!clk->enable_reg) {
 		/*
 		 * 'Independent' here refers to a clock which is not
 		 * controlled by its parent.
@@ -319,20 +396,44 @@ void _omap2_clk_disable(struct clk *clk)
 		return;
 	}
 
-	regval32 = __raw_readl(clk->enable_reg);
+	v = __raw_readl(clk->enable_reg);
 	if (clk->flags & INVERT_ENABLE)
-		regval32 |= (1 << clk->enable_bit);
+		v |= (1 << clk->enable_bit);
 	else
-		regval32 &= ~(1 << clk->enable_bit);
-	__raw_writel(regval32, clk->enable_reg);
-	wmb();
+		v &= ~(1 << clk->enable_bit);
+	__raw_writel(v, clk->enable_reg);
+	/* No OCP barrier needed here since it is a disable operation */
+}
+
+const struct clkops clkops_omap2_dflt_wait = {
+	.enable		= omap2_dflt_clk_enable_wait,
+	.disable	= omap2_dflt_clk_disable,
+};
+
+const struct clkops clkops_omap2_dflt = {
+	.enable		= omap2_dflt_clk_enable,
+	.disable	= omap2_dflt_clk_disable,
+};
+
+/* Enables clock without considering parent dependencies or use count
+ * REVISIT: Maybe change this to use clk->enable like on omap1?
+ */
+static int _omap2_clk_enable(struct clk *clk)
+{
+	return clk->ops->enable(clk);
+}
+
+/* Disables clock without considering parent dependencies or use count */
+static void _omap2_clk_disable(struct clk *clk)
+{
+	clk->ops->disable(clk);
 }
 
 void omap2_clk_disable(struct clk *clk)
 {
 	if (clk->usecount > 0 && !(--clk->usecount)) {
 		_omap2_clk_disable(clk);
-		if (likely((u32)clk->parent))
+		if (clk->parent)
 			omap2_clk_disable(clk->parent);
 		if (clk->clkdm)
 			omap2_clkdm_clk_disable(clk->clkdm, clk);
@@ -345,30 +446,29 @@ int omap2_clk_enable(struct clk *clk)
 	int ret = 0;
 
 	if (clk->usecount++ == 0) {
-		if (likely((u32)clk->parent))
-			ret = omap2_clk_enable(clk->parent);
-
-		if (unlikely(ret != 0)) {
-			clk->usecount--;
-			return ret;
-		}
-
 		if (clk->clkdm)
 			omap2_clkdm_clk_enable(clk->clkdm, clk);
 
-		ret = _omap2_clk_enable(clk);
-
-		if (unlikely(ret != 0)) {
-			if (clk->clkdm)
-				omap2_clkdm_clk_disable(clk->clkdm, clk);
+		if (clk->parent) {
+			ret = omap2_clk_enable(clk->parent);
+			if (ret)
+				goto err;
+		}
 
-			if (clk->parent) {
+		ret = _omap2_clk_enable(clk);
+		if (ret) {
+			if (clk->parent)
 				omap2_clk_disable(clk->parent);
-				clk->usecount--;
-			}
+
+			goto err;
 		}
 	}
+	return ret;
 
+err:
+	if (clk->clkdm)
+		omap2_clkdm_clk_disable(clk->clkdm, clk);
+	clk->usecount--;
 	return ret;
 }
 
@@ -376,24 +476,22 @@ int omap2_clk_enable(struct clk *clk)
  * Used for clocks that are part of CLKSEL_xyz governed clocks.
  * REVISIT: Maybe change to use clk->enable() functions like on omap1?
  */
-void omap2_clksel_recalc(struct clk *clk)
+unsigned long omap2_clksel_recalc(struct clk *clk)
 {
+	unsigned long rate;
 	u32 div = 0;
 
 	pr_debug("clock: recalc'ing clksel clk %s\n", clk->name);
 
 	div = omap2_clksel_get_divisor(clk);
 	if (div == 0)
-		return;
+		return clk->rate;
 
-	if (unlikely(clk->rate == clk->parent->rate / div))
-		return;
-	clk->rate = clk->parent->rate / div;
+	rate = clk->parent->rate / div;
 
-	pr_debug("clock: new clock rate is %ld (div %d)\n", clk->rate, div);
+	pr_debug("clock: new clock rate is %ld (div %d)\n", rate, div);
 
-	if (unlikely(clk->flags & RATE_PROPAGATES))
-		propagate_rate(clk);
+	return rate;
 }
 
 /**
@@ -405,8 +503,8 @@ void omap2_clksel_recalc(struct clk *clk)
  * the element associated with the supplied parent clock address.
  * Returns a pointer to the struct clksel on success or NULL on error.
  */
-const struct clksel *omap2_get_clksel_by_parent(struct clk *clk,
-						struct clk *src_clk)
+static const struct clksel *omap2_get_clksel_by_parent(struct clk *clk,
+						       struct clk *src_clk)
 {
 	const struct clksel *clks;
 
@@ -455,7 +553,7 @@ u32 omap2_clksel_round_rate_div(struct clk *clk, unsigned long target_rate,
 	*new_div = 1;
 
 	clks = omap2_get_clksel_by_parent(clk, clk->parent);
-	if (clks == NULL)
+	if (!clks)
 		return ~0;
 
 	for (clkr = clks->rates; clkr->div; clkr++) {
@@ -514,7 +612,7 @@ long omap2_clksel_round_rate(struct clk *clk, unsigned long target_rate)
 /* Given a clock and a rate apply a clock specific rounding function */
 long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
 {
-	if (clk->round_rate != NULL)
+	if (clk->round_rate)
 		return clk->round_rate(clk, rate);
 
 	if (clk->flags & RATE_FIXED)
@@ -540,7 +638,7 @@ u32 omap2_clksel_to_divisor(struct clk *clk, u32 field_val)
 	const struct clksel_rate *clkr;
 
 	clks = omap2_get_clksel_by_parent(clk, clk->parent);
-	if (clks == NULL)
+	if (!clks)
 		return 0;
 
 	for (clkr = clks->rates; clkr->div; clkr++) {
@@ -576,7 +674,7 @@ u32 omap2_divisor_to_clksel(struct clk *clk, u32 div)
 	WARN_ON(div == 0);
 
 	clks = omap2_get_clksel_by_parent(clk, clk->parent);
-	if (clks == NULL)
+	if (!clks)
 		return ~0;
 
 	for (clkr = clks->rates; clkr->div; clkr++) {
@@ -595,23 +693,6 @@ u32 omap2_divisor_to_clksel(struct clk *clk, u32 div)
 }
 
 /**
- * omap2_get_clksel - find clksel register addr & field mask for a clk
- * @clk: struct clk to use
- * @field_mask: ptr to u32 to store the register field mask
- *
- * Returns the address of the clksel register upon success or NULL on error.
- */
-void __iomem *omap2_get_clksel(struct clk *clk, u32 *field_mask)
-{
-	if (unlikely((clk->clksel_reg == NULL) || (clk->clksel_mask == NULL)))
-		return NULL;
-
-	*field_mask = clk->clksel_mask;
-
-	return clk->clksel_reg;
-}
-
-/**
  * omap2_clksel_get_divisor - get current divider applied to parent clock.
  * @clk: OMAP struct clk to use.
  *
@@ -619,49 +700,41 @@ void __iomem *omap2_get_clksel(struct clk *clk, u32 *field_mask)
  */
 u32 omap2_clksel_get_divisor(struct clk *clk)
 {
-	u32 field_mask, field_val;
-	void __iomem *div_addr;
+	u32 v;
 
-	div_addr = omap2_get_clksel(clk, &field_mask);
-	if (div_addr == NULL)
+	if (!clk->clksel_mask)
 		return 0;
 
-	field_val = __raw_readl(div_addr) & field_mask;
-	field_val >>= __ffs(field_mask);
+	v = __raw_readl(clk->clksel_reg) & clk->clksel_mask;
+	v >>= __ffs(clk->clksel_mask);
 
-	return omap2_clksel_to_divisor(clk, field_val);
+	return omap2_clksel_to_divisor(clk, v);
 }
 
 int omap2_clksel_set_rate(struct clk *clk, unsigned long rate)
 {
-	u32 field_mask, field_val, reg_val, validrate, new_div = 0;
-	void __iomem *div_addr;
+	u32 v, field_val, validrate, new_div = 0;
 
-	validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
-	if (validrate != rate)
+	if (!clk->clksel_mask)
 		return -EINVAL;
 
-	div_addr = omap2_get_clksel(clk, &field_mask);
-	if (div_addr == NULL)
+	validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
+	if (validrate != rate)
 		return -EINVAL;
 
 	field_val = omap2_divisor_to_clksel(clk, new_div);
 	if (field_val == ~0)
 		return -EINVAL;
 
-	reg_val = __raw_readl(div_addr);
-	reg_val &= ~field_mask;
-	reg_val |= (field_val << __ffs(field_mask));
-	__raw_writel(reg_val, div_addr);
-	wmb();
+	v = __raw_readl(clk->clksel_reg);
+	v &= ~clk->clksel_mask;
+	v |= field_val << __ffs(clk->clksel_mask);
+	__raw_writel(v, clk->clksel_reg);
+	v = __raw_readl(clk->clksel_reg); /* OCP barrier */
 
 	clk->rate = clk->parent->rate / new_div;
 
-	if (clk->flags & DELAYED_APP && cpu_is_omap24xx()) {
-		prm_write_mod_reg(OMAP24XX_VALID_CONFIG,
-			OMAP24XX_GR_MOD, OMAP24XX_PRCM_CLKCFG_CTRL_OFFSET);
-		wmb();
-	}
+	_omap2xxx_clk_commit(clk);
 
 	return 0;
 }
@@ -680,31 +753,24 @@ int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
 		return -EINVAL;
 
 	/* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
-	if (clk->set_rate != NULL)
+	if (clk->set_rate)
 		ret = clk->set_rate(clk, rate);
 
-	if (unlikely(ret == 0 && (clk->flags & RATE_PROPAGATES)))
-		propagate_rate(clk);
-
 	return ret;
 }
 
 /*
  * Converts encoded control register address into a full address
- * On error, *src_addr will be returned as 0.
+ * On error, the return value (parent_div) will be 0.
  */
-static u32 omap2_clksel_get_src_field(void __iomem **src_addr,
-				      struct clk *src_clk, u32 *field_mask,
-				      struct clk *clk, u32 *parent_div)
+static u32 _omap2_clksel_get_src_field(struct clk *src_clk, struct clk *clk,
+				       u32 *field_val)
 {
 	const struct clksel *clks;
 	const struct clksel_rate *clkr;
 
-	*parent_div = 0;
-	*src_addr = NULL;
-
 	clks = omap2_get_clksel_by_parent(clk, src_clk);
-	if (clks == NULL)
+	if (!clks)
 		return 0;
 
 	for (clkr = clks->rates; clkr->div; clkr++) {
@@ -722,47 +788,35 @@ static u32 omap2_clksel_get_src_field(void __iomem **src_addr,
 	/* Should never happen.  Add a clksel mask to the struct clk. */
 	WARN_ON(clk->clksel_mask == 0);
 
-	*field_mask = clk->clksel_mask;
-	*src_addr = clk->clksel_reg;
-	*parent_div = clkr->div;
+	*field_val = clkr->val;
 
-	return clkr->val;
+	return clkr->div;
 }
 
 int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
 {
-	void __iomem *src_addr;
-	u32 field_val, field_mask, reg_val, parent_div;
+	u32 field_val, v, parent_div;
 
-	if (unlikely(clk->flags & CONFIG_PARTICIPANT))
+	if (clk->flags & CONFIG_PARTICIPANT)
 		return -EINVAL;
 
 	if (!clk->clksel)
 		return -EINVAL;
 
-	field_val = omap2_clksel_get_src_field(&src_addr, new_parent,
-					       &field_mask, clk, &parent_div);
-	if (src_addr == NULL)
+	parent_div = _omap2_clksel_get_src_field(new_parent, clk, &field_val);
+	if (!parent_div)
 		return -EINVAL;
 
-	if (clk->usecount > 0)
-		omap2_clk_disable(clk);
-
 	/* Set new source value (previous dividers if any in effect) */
-	reg_val = __raw_readl(src_addr) & ~field_mask;
-	reg_val |= (field_val << __ffs(field_mask));
-	__raw_writel(reg_val, src_addr);
-	wmb();
-
-	if (clk->flags & DELAYED_APP && cpu_is_omap24xx()) {
-		__raw_writel(OMAP24XX_VALID_CONFIG, OMAP24XX_PRCM_CLKCFG_CTRL);
-		wmb();
-	}
+	v = __raw_readl(clk->clksel_reg);
+	v &= ~clk->clksel_mask;
+	v |= field_val << __ffs(clk->clksel_mask);
+	__raw_writel(v, clk->clksel_reg);
+	v = __raw_readl(clk->clksel_reg);    /* OCP barrier */
 
-	clk->parent = new_parent;
+	_omap2xxx_clk_commit(clk);
 
-	if (clk->usecount > 0)
-		omap2_clk_enable(clk);
+	clk_reparent(clk, new_parent);
 
 	/* CLKSEL clocks follow their parents' rates, divided by a divisor */
 	clk->rate = new_parent->rate;
@@ -773,9 +827,6 @@ int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
 	pr_debug("clock: set parent of %s to %s (new rate %ld)\n",
 		 clk->name, clk->parent->name, clk->rate);
 
-	if (unlikely(clk->flags & RATE_PROPAGATES))
-		propagate_rate(clk);
-
 	return 0;
 }
 
@@ -805,7 +856,8 @@ int omap2_dpll_set_rate_tolerance(struct clk *clk, unsigned int tolerance)
 	return 0;
 }
 
-static unsigned long _dpll_compute_new_rate(unsigned long parent_rate, unsigned int m, unsigned int n)
+static unsigned long _dpll_compute_new_rate(unsigned long parent_rate,
+					    unsigned int m, unsigned int n)
 {
 	unsigned long long num;
 
@@ -838,7 +890,7 @@ static int _dpll_test_mult(int *m, int n, unsigned long *new_rate,
 			   unsigned long target_rate,
 			   unsigned long parent_rate)
 {
-	int flags = 0, carry = 0;
+	int r = 0, carry = 0;
 
 	/* Unscale m and round if necessary */
 	if (*m % DPLL_SCALE_FACTOR >= DPLL_ROUNDING_VAL)
@@ -859,13 +911,13 @@ static int _dpll_test_mult(int *m, int n, unsigned long *new_rate,
 	if (*m < DPLL_MIN_MULTIPLIER) {
 		*m = DPLL_MIN_MULTIPLIER;
 		*new_rate = 0;
-		flags = DPLL_MULT_UNDERFLOW;
+		r = DPLL_MULT_UNDERFLOW;
 	}
 
 	if (*new_rate == 0)
 		*new_rate = _dpll_compute_new_rate(parent_rate, *m, n);
 
-	return flags;
+	return r;
 }
 
 /**
@@ -889,54 +941,65 @@ long omap2_dpll_round_rate(struct clk *clk, unsigned long target_rate)
 	int m, n, r, e, scaled_max_m;
 	unsigned long scaled_rt_rp, new_rate;
 	int min_e = -1, min_e_m = -1, min_e_n = -1;
+	struct dpll_data *dd;
 
 	if (!clk || !clk->dpll_data)
 		return ~0;
 
+	dd = clk->dpll_data;
+
 	pr_debug("clock: starting DPLL round_rate for clock %s, target rate "
 		 "%ld\n", clk->name, target_rate);
 
-	scaled_rt_rp = target_rate / (clk->parent->rate / DPLL_SCALE_FACTOR);
-	scaled_max_m = clk->dpll_data->max_multiplier * DPLL_SCALE_FACTOR;
+	scaled_rt_rp = target_rate / (dd->clk_ref->rate / DPLL_SCALE_FACTOR);
+	scaled_max_m = dd->max_multiplier * DPLL_SCALE_FACTOR;
 
-	clk->dpll_data->last_rounded_rate = 0;
+	dd->last_rounded_rate = 0;
 
-	for (n = clk->dpll_data->max_divider; n >= DPLL_MIN_DIVIDER; n--) {
+	for (n = dd->min_divider; n <= dd->max_divider; n++) {
+
+		/* Is the (input clk, divider) pair valid for the DPLL? */
+		r = _dpll_test_fint(clk, n);
+		if (r == DPLL_FINT_UNDERFLOW)
+			break;
+		else if (r == DPLL_FINT_INVALID)
+			continue;
 
 		/* Compute the scaled DPLL multiplier, based on the divider */
 		m = scaled_rt_rp * n;
 
 		/*
-		 * Since we're counting n down, a m overflow means we can
-		 * can immediately skip to the next n
+		 * Since we're counting n up, a m overflow means we
+		 * can bail out completely (since as n increases in
+		 * the next iteration, there's no way that m can
+		 * increase beyond the current m)
 		 */
 		if (m > scaled_max_m)
-			continue;
+			break;
 
 		r = _dpll_test_mult(&m, n, &new_rate, target_rate,
-				    clk->parent->rate);
+				    dd->clk_ref->rate);
+
+		/* m can't be set low enough for this n - try with a larger n */
+		if (r == DPLL_MULT_UNDERFLOW)
+			continue;
 
 		e = target_rate - new_rate;
 		pr_debug("clock: n = %d: m = %d: rate error is %d "
 			 "(new_rate = %ld)\n", n, m, e, new_rate);
 
 		if (min_e == -1 ||
-		    min_e >= (int)(abs(e) - clk->dpll_data->rate_tolerance)) {
+		    min_e >= (int)(abs(e) - dd->rate_tolerance)) {
 			min_e = e;
 			min_e_m = m;
 			min_e_n = n;
 
 			pr_debug("clock: found new least error %d\n", min_e);
-		}
 
-		/*
-		 * Since we're counting n down, a m underflow means we
-		 * can bail out completely (since as n decreases in
-		 * the next iteration, there's no way that m can
-		 * increase beyond the current m)
-		 */
-		if (r & DPLL_MULT_UNDERFLOW)
-			break;
+			/* We found good settings -- bail out now */
+			if (min_e <= dd->rate_tolerance)
+				break;
+		}
 	}
 
 	if (min_e < 0) {
@@ -944,17 +1007,17 @@ long omap2_dpll_round_rate(struct clk *clk, unsigned long target_rate)
 		return ~0;
 	}
 
-	clk->dpll_data->last_rounded_m = min_e_m;
-	clk->dpll_data->last_rounded_n = min_e_n;
-	clk->dpll_data->last_rounded_rate =
-		_dpll_compute_new_rate(clk->parent->rate, min_e_m,  min_e_n);
+	dd->last_rounded_m = min_e_m;
+	dd->last_rounded_n = min_e_n;
+	dd->last_rounded_rate = _dpll_compute_new_rate(dd->clk_ref->rate,
+						       min_e_m,  min_e_n);
 
 	pr_debug("clock: final least error: e = %d, m = %d, n = %d\n",
 		 min_e, min_e_m, min_e_n);
 	pr_debug("clock: final rate: %ld  (target rate: %ld)\n",
-		 clk->dpll_data->last_rounded_rate, target_rate);
+		 dd->last_rounded_rate, target_rate);
 
-	return clk->dpll_data->last_rounded_rate;
+	return dd->last_rounded_rate;
 }
 
 /*-------------------------------------------------------------------------
@@ -973,6 +1036,10 @@ void omap2_clk_disable_unused(struct clk *clk)
 		return;
 
 	printk(KERN_INFO "Disabling unused clock \"%s\"\n", clk->name);
-	_omap2_clk_disable(clk);
+	if (cpu_is_omap34xx()) {
+		omap2_clk_enable(clk);
+		omap2_clk_disable(clk);
+	} else
+		_omap2_clk_disable(clk);
 }
 #endif