[ARM] 3146/1: OMAP 3b/5: Add omap24xx clock framework

Patch from Tony Lindgren

This patch adds omap24xx specific clock code by
Richard Woodruff, Nishant Menon, Tony Lindgren et al.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 1129 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
new file mode 100644
index 000000000000..85818d9f2635
--- /dev/null
+++ b/arch/arm/mach-omap2/clock.c
@@ -0,0 +1,1129 @@
+/*
+ *  linux/arch/arm/mach-omap2/clock.c
+ *
+ *  Copyright (C) 2005 Texas Instruments Inc.
+ *  Richard Woodruff <r-woodruff2@ti.com>
+ *  Created for OMAP2.
+ *
+ *  Cleaned up and modified to use omap shared clock framework by
+ *  Tony Lindgren <tony@atomide.com>
+ *
+ *  Based on omap1 clock.c, Copyright (C) 2004 - 2005 Nokia corporation
+ *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+
+#include <asm/io.h>
+
+#include <asm/hardware/clock.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/sram.h>
+#include <asm/arch/prcm.h>
+
+#include "clock.h"
+
+//#define DOWN_VARIABLE_DPLL 1			/* Experimental */
+
+static struct prcm_config *curr_prcm_set;
+static struct memory_timings mem_timings;
+static u32 curr_perf_level = PRCM_FULL_SPEED;
+
+/*-------------------------------------------------------------------------
+ * Omap2 specific clock functions
+ *-------------------------------------------------------------------------*/
+
+/* Recalculate SYST_CLK */
+static void omap2_sys_clk_recalc(struct clk * clk)
+{
+	u32 div = PRCM_CLKSRC_CTRL;
+	div &= (1 << 7) | (1 << 6);	/* Test if ext clk divided by 1 or 2 */
+	div >>= clk->rate_offset;
+	clk->rate = (clk->parent->rate / div);
+	propagate_rate(clk);
+}
+
+static u32 omap2_get_dpll_rate(struct clk * tclk)
+{
+	int dpll_clk, dpll_mult, dpll_div, amult;
+
+	dpll_mult = (CM_CLKSEL1_PLL >> 12) & 0x03ff;	/* 10 bits */
+	dpll_div = (CM_CLKSEL1_PLL >> 8) & 0x0f;	/* 4 bits */
+	dpll_clk = (tclk->parent->rate * dpll_mult) / (dpll_div + 1);
+	amult = CM_CLKSEL2_PLL & 0x3;
+	dpll_clk *= amult;
+
+	return dpll_clk;
+}
+
+static void omap2_followparent_recalc(struct clk *clk)
+{
+	followparent_recalc(clk);
+}
+
+static void omap2_propagate_rate(struct clk * clk)
+{
+	if (!(clk->flags & RATE_FIXED))
+		clk->rate = clk->parent->rate;
+
+	propagate_rate(clk);
+}
+
+/* Enable an APLL if off */
+static void omap2_clk_fixed_enable(struct clk *clk)
+{
+	u32 cval, i=0;
+
+	if (clk->enable_bit == 0xff)			/* Parent will do it */
+		return;
+
+	cval = CM_CLKEN_PLL;
+
+	if ((cval & (0x3 << clk->enable_bit)) == (0x3 << clk->enable_bit))
+		return;
+
+	cval &= ~(0x3 << clk->enable_bit);
+	cval |= (0x3 << clk->enable_bit);
+	CM_CLKEN_PLL = cval;
+
+	if (clk == &apll96_ck)
+		cval = (1 << 8);
+	else if (clk == &apll54_ck)
+		cval = (1 << 6);
+
+	while (!CM_IDLEST_CKGEN & cval) {		/* Wait for lock */
+		++i;
+		udelay(1);
+		if (i == 100000)
+			break;
+	}
+}
+
+/* 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)
+{
+	u32 regval32;
+
+	if (clk->flags & ALWAYS_ENABLED)
+		return 0;
+
+	if (unlikely(clk->enable_reg == 0)) {
+		printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
+		       clk->name);
+		return 0;
+	}
+
+	if (clk->enable_reg == (void __iomem *)&CM_CLKEN_PLL) {
+		omap2_clk_fixed_enable(clk);
+		return 0;
+	}
+
+	regval32 = __raw_readl(clk->enable_reg);
+	regval32 |= (1 << clk->enable_bit);
+	__raw_writel(regval32, clk->enable_reg);
+
+	return 0;
+}
+
+/* Stop APLL */
+static void omap2_clk_fixed_disable(struct clk *clk)
+{
+	u32 cval;
+
+	if(clk->enable_bit == 0xff)		/* let parent off do it */
+		return;
+
+	cval = CM_CLKEN_PLL;
+	cval &= ~(0x3 << clk->enable_bit);
+	CM_CLKEN_PLL = cval;
+}
+
+/* Disables clock without considering parent dependencies or use count */
+static void omap2_clk_disable(struct clk *clk)
+{
+	u32 regval32;
+
+	if (clk->enable_reg == 0)
+		return;
+
+	if (clk->enable_reg == (void __iomem *)&CM_CLKEN_PLL) {
+		omap2_clk_fixed_disable(clk);
+		return;
+	}
+
+	regval32 = __raw_readl(clk->enable_reg);
+	regval32 &= ~(1 << clk->enable_bit);
+	__raw_writel(regval32, clk->enable_reg);
+}
+
+static int omap2_clk_use(struct clk *clk)
+{
+	int ret = 0;
+
+	if (clk->usecount++ == 0) {
+		if (likely((u32)clk->parent))
+			ret = omap2_clk_use(clk->parent);
+
+		if (unlikely(ret != 0)) {
+			clk->usecount--;
+			return ret;
+		}
+
+		ret = omap2_clk_enable(clk);
+
+		if (unlikely(ret != 0) && clk->parent) {
+			omap2_clk_unuse(clk->parent);
+			clk->usecount--;
+		}
+	}
+
+	return ret;
+}
+
+static void omap2_clk_unuse(struct clk *clk)
+{
+	if (clk->usecount > 0 && !(--clk->usecount)) {
+		omap2_clk_disable(clk);
+		if (likely((u32)clk->parent))
+			omap2_clk_unuse(clk->parent);
+	}
+}
+
+/*
+ * Uses the current prcm set to tell if a rate is valid.
+ * You can go slower, but not faster within a given rate set.
+ */
+static u32 omap2_dpll_round_rate(unsigned long target_rate)
+{
+	u32 high, low;
+
+	if ((CM_CLKSEL2_PLL & 0x3) == 1) {	/* DPLL clockout */
+		high = curr_prcm_set->dpll_speed * 2;
+		low = curr_prcm_set->dpll_speed;
+	} else {				/* DPLL clockout x 2 */
+		high = curr_prcm_set->dpll_speed;
+		low = curr_prcm_set->dpll_speed / 2;
+	}
+
+#ifdef DOWN_VARIABLE_DPLL
+	if (target_rate > high)
+		return high;
+	else
+		return target_rate;
+#else
+	if (target_rate > low)
+		return high;
+	else
+		return low;
+#endif
+
+}
+
+/*
+ * Used for clocks that are part of CLKSEL_xyz governed clocks.
+ * REVISIT: Maybe change to use clk->enable() functions like on omap1?
+ */
+static void omap2_clksel_recalc(struct clk * clk)
+{
+	u32 fixed = 0, div = 0;
+
+	if (clk == &dpll_ck) {
+		clk->rate = omap2_get_dpll_rate(clk);
+		fixed = 1;
+		div = 0;
+	}
+
+	if (clk == &iva1_mpu_int_ifck) {
+		div = 2;
+		fixed = 1;
+	}
+
+	if ((clk == &dss1_fck) && ((CM_CLKSEL1_CORE & (0x1f << 8)) == 0)) {
+		clk->rate = sys_ck.rate;
+		return;
+	}
+
+	if (!fixed) {
+		div = omap2_clksel_get_divisor(clk);
+		if (div == 0)
+			return;
+	}
+
+	if (div != 0) {
+		if (unlikely(clk->rate == clk->parent->rate / div))
+			return;
+		clk->rate = clk->parent->rate / div;
+	}
+
+	if (unlikely(clk->flags & RATE_PROPAGATES))
+		propagate_rate(clk);
+}
+
+/*
+ * Finds best divider value in an array based on the source and target
+ * rates. The divider array must be sorted with smallest divider first.
+ */
+static inline u32 omap2_divider_from_table(u32 size, u32 *div_array,
+					   u32 src_rate, u32 tgt_rate)
+{
+	int i, test_rate;
+
+	if (div_array == NULL)
+		return ~1;
+
+	for (i=0; i < size; i++) {
+		test_rate = src_rate / *div_array;
+		if (test_rate <= tgt_rate)
+			return *div_array;
+		++div_array;
+	}
+
+	return ~0;	/* No acceptable divider */
+}
+
+/*
+ * Find divisor for the given clock and target rate.
+ *
+ * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
+ * they are only settable as part of virtual_prcm set.
+ */
+static u32 omap2_clksel_round_rate(struct clk *tclk, u32 target_rate,
+	u32 *new_div)
+{
+	u32 gfx_div[] = {2, 3, 4};
+	u32 sysclkout_div[] = {1, 2, 4, 8, 16};
+	u32 dss1_div[] = {1, 2, 3, 4, 5, 6, 8, 9, 12, 16};
+	u32 vylnq_div[] = {1, 2, 3, 4, 6, 8, 9, 12, 16, 18};
+	u32 best_div = ~0, asize = 0;
+	u32 *div_array = NULL;
+
+	switch (tclk->flags & SRC_RATE_SEL_MASK) {
+	case CM_GFX_SEL1:
+		asize = 3;
+		div_array = gfx_div;
+		break;
+	case CM_PLL_SEL1:
+		return omap2_dpll_round_rate(target_rate);
+	case CM_SYSCLKOUT_SEL1:
+		asize = 5;
+		div_array = sysclkout_div;
+		break;
+	case CM_CORE_SEL1:
+		if(tclk == &dss1_fck){
+			if(tclk->parent == &core_ck){
+				asize = 10;
+				div_array = dss1_div;
+			} else {
+				*new_div = 0; /* fixed clk */
+				return(tclk->parent->rate);
+			}
+		} else if((tclk == &vlynq_fck) && cpu_is_omap2420()){
+			if(tclk->parent == &core_ck){
+				asize = 10;
+				div_array = vylnq_div;
+			} else {
+				*new_div = 0; /* fixed clk */
+				return(tclk->parent->rate);
+			}
+		}
+		break;
+	}
+
+	best_div = omap2_divider_from_table(asize, div_array,
+	 tclk->parent->rate, target_rate);
+	if (best_div == ~0){
+		*new_div = 1;
+		return best_div; /* signal error */
+	}
+
+	*new_div = best_div;
+	return (tclk->parent->rate / best_div);
+}
+
+/* Given a clock and a rate apply a clock specific rounding function */
+static long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	u32 new_div = 0;
+	int valid_rate;
+
+	if (clk->flags & RATE_FIXED)
+		return clk->rate;
+
+	if (clk->flags & RATE_CKCTL) {
+		valid_rate = omap2_clksel_round_rate(clk, rate, &new_div);
+		return valid_rate;
+	}
+
+	if (clk->round_rate != 0)
+		return clk->round_rate(clk, rate);
+
+	return clk->rate;
+}
+
+/*
+ * Check the DLL lock state, and return tue if running in unlock mode.
+ * This is needed to compenste for the shifted DLL value in unlock mode.
+ */
+static u32 omap2_dll_force_needed(void)
+{
+	u32 dll_state = SDRC_DLLA_CTRL;		/* dlla and dllb are a set */
+
+	if ((dll_state & (1 << 2)) == (1 << 2))
+		return 1;
+	else
+		return 0;
+}
+
+static void omap2_init_memory_params(u32 force_lock_to_unlock_mode)
+{
+	unsigned long dll_cnt;
+	u32 fast_dll = 0;
+
+	mem_timings.m_type = !((SDRC_MR_0 & 0x3) == 0x1); /* DDR = 1, SDR = 0 */
+
+	/* 2422 es2.05 and beyond has a single SIP DDR instead of 2 like others.
+	 * In the case of 2422, its ok to use CS1 instead of CS0.
+	 */
+
+#if 0	/* FIXME: Enable after 24xx cpu detection works */
+	ctype = get_cpu_type();
+	if (cpu_is_omap2422())
+		mem_timings.base_cs = 1;
+	else
+#endif
+		mem_timings.base_cs = 0;
+
+	if (mem_timings.m_type != M_DDR)
+		return;
+
+	/* With DDR we need to determine the low frequency DLL value */
+	if (((mem_timings.fast_dll_ctrl & (1 << 2)) == M_LOCK_CTRL))
+		mem_timings.dll_mode = M_UNLOCK;
+	else
+		mem_timings.dll_mode = M_LOCK;
+
+	if (mem_timings.base_cs == 0) {
+		fast_dll = SDRC_DLLA_CTRL;
+		dll_cnt = SDRC_DLLA_STATUS & 0xff00;
+	} else {
+		fast_dll = SDRC_DLLB_CTRL;
+		dll_cnt = SDRC_DLLB_STATUS & 0xff00;
+	}
+	if (force_lock_to_unlock_mode) {
+		fast_dll &= ~0xff00;
+		fast_dll |= dll_cnt;		/* Current lock mode */
+	}
+	mem_timings.fast_dll_ctrl = fast_dll;
+
+	/* No disruptions, DDR will be offline & C-ABI not followed */
+	omap2_sram_ddr_init(&mem_timings.slow_dll_ctrl,
+			    mem_timings.fast_dll_ctrl,
+			    mem_timings.base_cs,
+			    force_lock_to_unlock_mode);
+	mem_timings.slow_dll_ctrl &= 0xff00;	/* Keep lock value */
+
+	/* Turn status into unlock ctrl */
+	mem_timings.slow_dll_ctrl |=
+		((mem_timings.fast_dll_ctrl & 0xF) | (1 << 2));
+
+	/* 90 degree phase for anything below 133Mhz */
+	mem_timings.slow_dll_ctrl |= (1 << 1);
+}
+
+static u32 omap2_reprogram_sdrc(u32 level, u32 force)
+{
+	u32 prev = curr_perf_level, flags;
+
+	if ((curr_perf_level == level) && !force)
+		return prev;
+
+	if (level == PRCM_HALF_SPEED) {
+		local_irq_save(flags);
+		PRCM_VOLTSETUP = 0xffff;
+		omap2_sram_reprogram_sdrc(PRCM_HALF_SPEED,
+					  mem_timings.slow_dll_ctrl,
+					  mem_timings.m_type);
+		curr_perf_level = PRCM_HALF_SPEED;
+		local_irq_restore(flags);
+	}
+	if (level == PRCM_FULL_SPEED) {
+		local_irq_save(flags);
+		PRCM_VOLTSETUP = 0xffff;
+		omap2_sram_reprogram_sdrc(PRCM_FULL_SPEED,
+					  mem_timings.fast_dll_ctrl,
+					  mem_timings.m_type);
+		curr_perf_level = PRCM_FULL_SPEED;
+		local_irq_restore(flags);
+	}
+
+	return prev;
+}
+
+static int omap2_reprogram_dpll(struct clk * clk, unsigned long rate)
+{
+	u32 flags, cur_rate, low, mult, div, valid_rate, done_rate;
+	u32 bypass = 0;
+	struct prcm_config tmpset;
+	int ret = -EINVAL;
+
+	local_irq_save(flags);
+	cur_rate = omap2_get_dpll_rate(&dpll_ck);
+	mult = CM_CLKSEL2_PLL & 0x3;
+
+	if ((rate == (cur_rate / 2)) && (mult == 2)) {
+		omap2_reprogram_sdrc(PRCM_HALF_SPEED, 1);
+	} else if ((rate == (cur_rate * 2)) && (mult == 1)) {
+		omap2_reprogram_sdrc(PRCM_FULL_SPEED, 1);
+	} else if (rate != cur_rate) {
+		valid_rate = omap2_dpll_round_rate(rate);
+		if (valid_rate != rate)
+			goto dpll_exit;
+
+		if ((CM_CLKSEL2_PLL & 0x3) == 1)
+			low = curr_prcm_set->dpll_speed;
+		else
+			low = curr_prcm_set->dpll_speed / 2;
+
+		tmpset.cm_clksel1_pll = CM_CLKSEL1_PLL;
+		tmpset.cm_clksel1_pll &= ~(0x3FFF << 8);
+		div = ((curr_prcm_set->xtal_speed / 1000000) - 1);
+		tmpset.cm_clksel2_pll = CM_CLKSEL2_PLL;
+		tmpset.cm_clksel2_pll &= ~0x3;
+		if (rate > low) {
+			tmpset.cm_clksel2_pll |= 0x2;
+			mult = ((rate / 2) / 1000000);
+			done_rate = PRCM_FULL_SPEED;
+		} else {
+			tmpset.cm_clksel2_pll |= 0x1;
+			mult = (rate / 1000000);
+			done_rate = PRCM_HALF_SPEED;
+		}
+		tmpset.cm_clksel1_pll |= ((div << 8) | (mult << 12));
+
+		/* Worst case */
+		tmpset.base_sdrc_rfr = V24XX_SDRC_RFR_CTRL_BYPASS;
+
+		if (rate == curr_prcm_set->xtal_speed)	/* If asking for 1-1 */
+			bypass = 1;
+
+		omap2_reprogram_sdrc(PRCM_FULL_SPEED, 1); /* For init_mem */
+
+		/* Force dll lock mode */
+		omap2_set_prcm(tmpset.cm_clksel1_pll, tmpset.base_sdrc_rfr,
+			       bypass);
+
+		/* Errata: ret dll entry state */
+		omap2_init_memory_params(omap2_dll_force_needed());
+		omap2_reprogram_sdrc(done_rate, 0);
+	}
+	omap2_clksel_recalc(&dpll_ck);
+	ret = 0;
+
+dpll_exit:
+	local_irq_restore(flags);
+	return(ret);
+}
+
+/* Just return the MPU speed */
+static void omap2_mpu_recalc(struct clk * clk)
+{
+	clk->rate = curr_prcm_set->mpu_speed;
+}
+
+/*
+ * Look for a rate equal or less than the target rate given a configuration set.
+ *
+ * What's not entirely clear is "which" field represents the key field.
+ * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
+ * just uses the ARM rates.
+ */
+static long omap2_round_to_table_rate(struct clk * clk, unsigned long rate)
+{
+	struct prcm_config * ptr;
+	long highest_rate;
+
+	if (clk != &virt_prcm_set)
+		return -EINVAL;
+
+	highest_rate = -EINVAL;
+
+	for (ptr = rate_table; ptr->mpu_speed; ptr++) {
+		if (ptr->xtal_speed != sys_ck.rate)
+			continue;
+
+		highest_rate = ptr->mpu_speed;
+
+		/* Can check only after xtal frequency check */
+		if (ptr->mpu_speed <= rate)
+			break;
+	}
+	return highest_rate;
+}
+
+/*
+ * omap2_convert_field_to_div() - turn field value into integer divider
+ */
+static u32 omap2_clksel_to_divisor(u32 div_sel, u32 field_val)
+{
+	u32 i;
+	u32 clkout_array[] = {1, 2, 4, 8, 16};
+
+	if ((div_sel & SRC_RATE_SEL_MASK) == CM_SYSCLKOUT_SEL1) {
+		for (i = 0; i < 5; i++) {
+			if (field_val == i)
+				return clkout_array[i];
+		}
+		return ~0;
+	} else
+		return field_val;
+}
+
+/*
+ * Returns the CLKSEL divider register value
+ * REVISIT: This should be cleaned up to work nicely with void __iomem *
+ */
+static u32 omap2_get_clksel(u32 *div_sel, u32 *field_mask,
+			    struct clk *clk)
+{
+	int ret = ~0;
+	u32 reg_val, div_off;
+	u32 div_addr = 0;
+	u32 mask = ~0;
+
+	div_off = clk->rate_offset;
+
+	switch ((*div_sel & SRC_RATE_SEL_MASK)) {
+	case CM_MPU_SEL1:
+		div_addr = (u32)&CM_CLKSEL_MPU;
+		mask = 0x1f;
+		break;
+	case CM_DSP_SEL1:
+		div_addr = (u32)&CM_CLKSEL_DSP;
+		if (cpu_is_omap2420()) {
+			if ((div_off == 0) || (div_off == 8))
+				mask = 0x1f;
+			else if (div_off == 5)
+				mask = 0x3;
+		} else if (cpu_is_omap2430()) {
+			if (div_off == 0)
+				mask = 0x1f;
+			else if (div_off == 5)
+				mask = 0x3;
+		}
+		break;
+	case CM_GFX_SEL1:
+		div_addr = (u32)&CM_CLKSEL_GFX;
+		if (div_off == 0)
+			mask = 0x7;
+		break;
+	case CM_MODEM_SEL1:
+		div_addr = (u32)&CM_CLKSEL_MDM;
+		if (div_off == 0)
+			mask = 0xf;
+		break;
+	case CM_SYSCLKOUT_SEL1:
+		div_addr = (u32)&PRCM_CLKOUT_CTRL;
+		if ((div_off == 3) || (div_off = 11))
+			mask= 0x3;
+		break;
+	case CM_CORE_SEL1:
+		div_addr = (u32)&CM_CLKSEL1_CORE;
+		switch (div_off) {
+		case 0:					/* l3 */
+		case 8:					/* dss1 */
+		case 15:				/* vylnc-2420 */
+		case 20:				/* ssi */
+			mask = 0x1f; break;
+		case 5:					/* l4 */
+			mask = 0x3; break;
+		case 13:				/* dss2 */
+			mask = 0x1; break;
+		case 25:				/* usb */
+			mask = 0xf; break;
+		}
+	}
+
+	*field_mask = mask;
+
+	if (unlikely(mask == ~0))
+		div_addr = 0;
+
+	*div_sel = div_addr;
+
+	if (unlikely(div_addr == 0))
+		return ret;
+
+	/* Isolate field */
+	reg_val = __raw_readl((void __iomem *)div_addr) & (mask << div_off);
+
+	/* Normalize back to divider value */
+	reg_val >>= div_off;
+
+	return reg_val;
+}
+
+/*
+ * Return divider to be applied to parent clock.
+ * Return 0 on error.
+ */
+static u32 omap2_clksel_get_divisor(struct clk *clk)
+{
+	int ret = 0;
+	u32 div, div_sel, div_off, field_mask, field_val;
+
+	/* isolate control register */
+	div_sel = (SRC_RATE_SEL_MASK & clk->flags);
+
+	div_off = clk->rate_offset;
+	field_val = omap2_get_clksel(&div_sel, &field_mask, clk);
+	if (div_sel == 0)
+		return ret;
+
+	div_sel = (SRC_RATE_SEL_MASK & clk->flags);
+	div = omap2_clksel_to_divisor(div_sel, field_val);
+
+	return div;
+}
+
+/* Set the clock rate for a clock source */
+static int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
+
+{
+	int ret = -EINVAL;
+	void __iomem * reg;
+	u32 div_sel, div_off, field_mask, field_val, reg_val, validrate;
+	u32 new_div = 0;
+
+	if (!(clk->flags & CONFIG_PARTICIPANT) && (clk->flags & RATE_CKCTL)) {
+		if (clk == &dpll_ck)
+			return omap2_reprogram_dpll(clk, rate);
+
+		/* Isolate control register */
+		div_sel = (SRC_RATE_SEL_MASK & clk->flags);
+		div_off = clk->src_offset;
+
+		validrate = omap2_clksel_round_rate(clk, rate, &new_div);
+		if(validrate != rate)
+			return(ret);
+
+		field_val = omap2_get_clksel(&div_sel, &field_mask, clk);
+		if (div_sel == 0)
+			return ret;
+
+		if(clk->flags & CM_SYSCLKOUT_SEL1){
+			switch(new_div){
+			case 16: field_val = 4; break;
+			case 8:  field_val = 3; break;
+			case 4:  field_val = 2; break;
+			case 2:  field_val = 1; break;
+			case 1:  field_val = 0; break;
+			}
+		}
+		else
+			field_val = new_div;
+
+		reg = (void __iomem *)div_sel;
+
+		reg_val = __raw_readl(reg);
+		reg_val &= ~(field_mask << div_off);
+		reg_val |= (field_val << div_off);
+
+		__raw_writel(reg_val, reg);
+		clk->rate = clk->parent->rate / field_val;
+
+		if (clk->flags & DELAYED_APP)
+			__raw_writel(0x1, (void __iomem *)&PRCM_CLKCFG_CTRL);
+		ret = 0;
+	} else if (clk->set_rate != 0)
+		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 */
+static u32 omap2_get_src_field(u32 *type_to_addr, u32 reg_offset,
+			       struct clk *src_clk, u32 *field_mask)
+{
+	u32 val = ~0, src_reg_addr = 0, mask = 0;
+
+	/* Find target control register.*/
+	switch ((*type_to_addr & SRC_RATE_SEL_MASK)) {
+	case CM_CORE_SEL1:
+		src_reg_addr = (u32)&CM_CLKSEL1_CORE;
+		if (reg_offset == 13) {			/* DSS2_fclk */
+			mask = 0x1;
+			if (src_clk == &sys_ck)
+				val = 0;
+			if (src_clk == &func_48m_ck)
+				val = 1;
+		} else if (reg_offset == 8) {		/* DSS1_fclk */
+			mask = 0x1f;
+			if (src_clk == &sys_ck)
+				val = 0;
+			else if (src_clk == &core_ck)	/* divided clock */
+				val = 0x10;		/* rate needs fixing */
+		} else if ((reg_offset == 15) && cpu_is_omap2420()){ /*vlnyq*/
+			mask = 0x1F;
+			if(src_clk == &func_96m_ck)
+				val = 0;
+			else if (src_clk == &core_ck)
+				val = 0x10;
+		}
+		break;
+	case CM_CORE_SEL2:
+		src_reg_addr = (u32)&CM_CLKSEL2_CORE;
+		mask = 0x3;
+		if (src_clk == &func_32k_ck)
+			val = 0x0;
+		if (src_clk == &sys_ck)
+			val = 0x1;
+		if (src_clk == &alt_ck)
+			val = 0x2;
+		break;
+	case CM_WKUP_SEL1:
+		src_reg_addr = (u32)&CM_CLKSEL2_CORE;
+		mask = 0x3;
+		if (src_clk == &func_32k_ck)
+			val = 0x0;
+		if (src_clk == &sys_ck)
+			val = 0x1;
+		if (src_clk == &alt_ck)
+			val = 0x2;
+		break;
+	case CM_PLL_SEL1:
+		src_reg_addr = (u32)&CM_CLKSEL1_PLL;
+		mask = 0x1;
+		if (reg_offset == 0x3) {
+			if (src_clk == &apll96_ck)
+				val = 0;
+			if (src_clk == &alt_ck)
+				val = 1;
+		}
+		else if (reg_offset == 0x5) {
+			if (src_clk == &apll54_ck)
+				val = 0;
+			if (src_clk == &alt_ck)
+				val = 1;
+		}
+		break;
+	case CM_PLL_SEL2:
+		src_reg_addr = (u32)&CM_CLKSEL2_PLL;
+		mask = 0x3;
+		if (src_clk == &func_32k_ck)
+			val = 0x0;
+		if (src_clk == &dpll_ck)
+			val = 0x2;
+		break;
+	case CM_SYSCLKOUT_SEL1:
+		src_reg_addr = (u32)&PRCM_CLKOUT_CTRL;
+		mask = 0x3;
+		if (src_clk == &dpll_ck)
+			val = 0;
+		if (src_clk == &sys_ck)
+			val = 1;
+		if (src_clk == &func_54m_ck)
+			val = 2;
+		if (src_clk == &func_96m_ck)
+			val = 3;
+		break;
+	}
+
+	if (val == ~0)			/* Catch errors in offset */
+		*type_to_addr = 0;
+	else
+		*type_to_addr = src_reg_addr;
+	*field_mask = mask;
+
+	return val;
+}
+
+static int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
+{
+	void __iomem * reg;
+	u32 src_sel, src_off, field_val, field_mask, reg_val, rate;
+	int ret = -EINVAL;
+
+	if (unlikely(clk->flags & CONFIG_PARTICIPANT))
+		return ret;
+
+	if (clk->flags & SRC_SEL_MASK) {	/* On-chip SEL collection */
+		src_sel = (SRC_RATE_SEL_MASK & clk->flags);
+		src_off = clk->src_offset;
+
+		if (src_sel == 0)
+			goto set_parent_error;
+
+		field_val = omap2_get_src_field(&src_sel, src_off, new_parent,
+						&field_mask);
+
+		reg = (void __iomem *)src_sel;
+
+		if (clk->usecount > 0)
+			omap2_clk_disable(clk);
+
+		/* Set new source value (previous dividers if any in effect) */
+		reg_val = __raw_readl(reg) & ~(field_mask << src_off);
+		reg_val |= (field_val << src_off);
+		__raw_writel(reg_val, reg);
+
+		if (clk->flags & DELAYED_APP)
+			__raw_writel(0x1, (void __iomem *)&PRCM_CLKCFG_CTRL);
+
+		if (clk->usecount > 0)
+			omap2_clk_enable(clk);
+
+		clk->parent = new_parent;
+
+		/* SRC_RATE_SEL_MASK clocks follow their parents rates.*/
+		if ((new_parent == &core_ck) && (clk == &dss1_fck))
+			clk->rate = new_parent->rate / 0x10;
+		else
+			clk->rate = new_parent->rate;
+
+		if (unlikely(clk->flags & RATE_PROPAGATES))
+			propagate_rate(clk);
+
+		return 0;
+	} else {
+		clk->parent = new_parent;
+		rate = new_parent->rate;
+		omap2_clk_set_rate(clk, rate);
+		ret = 0;
+	}
+
+ set_parent_error:
+	return ret;
+}
+
+/* Sets basic clocks based on the specified rate */
+static int omap2_select_table_rate(struct clk * clk, unsigned long rate)
+{
+	u32 flags, cur_rate, done_rate, bypass = 0;
+	u8 cpu_mask = 0;
+	struct prcm_config *prcm;
+	unsigned long found_speed = 0;
+
+	if (clk != &virt_prcm_set)
+		return -EINVAL;
+
+	/* FIXME: Change cpu_is_omap2420() to cpu_is_omap242x() */
+	if (cpu_is_omap2420())
+		cpu_mask = RATE_IN_242X;
+	else if (cpu_is_omap2430())
+		cpu_mask = RATE_IN_243X;
+
+	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
+		if (!(prcm->flags & cpu_mask))
+			continue;
+
+		if (prcm->xtal_speed != sys_ck.rate)
+			continue;
+
+		if (prcm->mpu_speed <= rate) {
+			found_speed = prcm->mpu_speed;
+			break;
+		}
+	}
+
+	if (!found_speed) {
+		printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
+	 rate / 1000000);
+		return -EINVAL;
+	}
+
+	curr_prcm_set = prcm;
+	cur_rate = omap2_get_dpll_rate(&dpll_ck);
+
+	if (prcm->dpll_speed == cur_rate / 2) {
+		omap2_reprogram_sdrc(PRCM_HALF_SPEED, 1);
+	} else if (prcm->dpll_speed == cur_rate * 2) {
+		omap2_reprogram_sdrc(PRCM_FULL_SPEED, 1);
+	} else if (prcm->dpll_speed != cur_rate) {
+		local_irq_save(flags);
+
+		if (prcm->dpll_speed == prcm->xtal_speed)
+			bypass = 1;
+
+		if ((prcm->cm_clksel2_pll & 0x3) == 2)
+			done_rate = PRCM_FULL_SPEED;
+		else
+			done_rate = PRCM_HALF_SPEED;
+
+		/* MPU divider */
+		CM_CLKSEL_MPU = prcm->cm_clksel_mpu;
+
+		/* dsp + iva1 div(2420), iva2.1(2430) */
+		CM_CLKSEL_DSP = prcm->cm_clksel_dsp;
+
+		CM_CLKSEL_GFX = prcm->cm_clksel_gfx;
+
+		/* Major subsystem dividers */
+		CM_CLKSEL1_CORE = prcm->cm_clksel1_core;
+		if (cpu_is_omap2430())
+			CM_CLKSEL_MDM = prcm->cm_clksel_mdm;
+
+		/* x2 to enter init_mem */
+		omap2_reprogram_sdrc(PRCM_FULL_SPEED, 1);
+
+		omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
+			       bypass);
+
+		omap2_init_memory_params(omap2_dll_force_needed());
+		omap2_reprogram_sdrc(done_rate, 0);
+
+		local_irq_restore(flags);
+	}
+	omap2_clksel_recalc(&dpll_ck);
+
+	return 0;
+}
+
+/*-------------------------------------------------------------------------
+ * Omap2 clock reset and init functions
+ *-------------------------------------------------------------------------*/
+
+static struct clk_functions omap2_clk_functions = {
+	.clk_enable		= omap2_clk_enable,
+	.clk_disable		= omap2_clk_disable,
+	.clk_use		= omap2_clk_use,
+	.clk_unuse		= omap2_clk_unuse,
+	.clk_round_rate		= omap2_clk_round_rate,
+	.clk_set_rate		= omap2_clk_set_rate,
+	.clk_set_parent		= omap2_clk_set_parent,
+};
+
+static void __init omap2_get_crystal_rate(struct clk *osc, struct clk *sys)
+{
+	u32 div, aplls, sclk = 13000000;
+
+	aplls = CM_CLKSEL1_PLL;
+	aplls &= ((1 << 23) | (1 << 24) | (1 << 25));
+	aplls >>= 23;			/* Isolate field, 0,2,3 */
+
+	if (aplls == 0)
+		sclk = 19200000;
+	else if (aplls == 2)
+		sclk = 13000000;
+	else if (aplls == 3)
+		sclk = 12000000;
+
+	div = PRCM_CLKSRC_CTRL;
+	div &= ((1 << 7) | (1 << 6));
+	div >>= sys->rate_offset;
+
+	osc->rate = sclk * div;
+	sys->rate = sclk;
+}
+
+#ifdef CONFIG_OMAP_RESET_CLOCKS
+static void __init omap2_disable_unused_clocks(void)
+{
+	struct clk *ck;
+	u32 regval32;
+
+	list_for_each_entry(ck, &clocks, node) {
+		if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
+			ck->enable_reg == 0)
+			continue;
+
+		regval32 = __raw_readl(ck->enable_reg);
+		if ((regval32 & (1 << ck->enable_bit)) == 0)
+			continue;
+
+		printk(KERN_INFO "Disabling unused clock \"%s\"\n", ck->name);
+		omap2_clk_disable(ck);
+	}
+}
+late_initcall(omap2_disable_unused_clocks);
+#endif
+
+/*
+ * Switch the MPU rate if specified on cmdline.
+ * We cannot do this early until cmdline is parsed.
+ */
+static int __init omap2_clk_arch_init(void)
+{
+	if (!mpurate)
+		return -EINVAL;
+
+	if (omap2_select_table_rate(&virt_prcm_set, mpurate))
+		printk(KERN_ERR "Could not find matching MPU rate\n");
+
+	propagate_rate(&osc_ck);		/* update main root fast */
+	propagate_rate(&func_32k_ck);		/* update main root slow */
+
+	printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL/MPU): "
+	       "%ld.%01ld/%ld/%ld MHz\n",
+	       (sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
+	       (dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;
+
+	return 0;
+}
+arch_initcall(omap2_clk_arch_init);
+
+int __init omap2_clk_init(void)
+{
+	struct prcm_config *prcm;
+	struct clk ** clkp;
+	u32 clkrate;
+
+	clk_init(&omap2_clk_functions);
+	omap2_get_crystal_rate(&osc_ck, &sys_ck);
+
+	for (clkp = onchip_clks; clkp < onchip_clks + ARRAY_SIZE(onchip_clks);
+	     clkp++) {
+
+		if ((*clkp)->flags & CLOCK_IN_OMAP242X && cpu_is_omap2420()) {
+			clk_register(*clkp);
+			continue;
+		}
+
+		if ((*clkp)->flags & CLOCK_IN_OMAP243X && cpu_is_omap2430()) {
+			clk_register(*clkp);
+			continue;
+		}
+	}
+
+	/* Check the MPU rate set by bootloader */
+	clkrate = omap2_get_dpll_rate(&dpll_ck);
+	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
+		if (prcm->xtal_speed != sys_ck.rate)
+			continue;
+		if (prcm->dpll_speed <= clkrate)
+			 break;
+	}
+	curr_prcm_set = prcm;
+
+	propagate_rate(&osc_ck);		/* update main root fast */
+	propagate_rate(&func_32k_ck);		/* update main root slow */
+
+	printk(KERN_INFO "Clocking rate (Crystal/DPLL/MPU): "
+	       "%ld.%01ld/%ld/%ld MHz\n",
+	       (sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
+	       (dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;
+
+	/*
+	 * Only enable those clocks we will need, let the drivers
+	 * enable other clocks as necessary
+	 */
+	clk_use(&sync_32k_ick);
+	clk_use(&omapctrl_ick);
+	if (cpu_is_omap2430())
+		clk_use(&sdrc_ick);
+
+	return 0;
+}