arch/arm/mach-omap1/clock.c - kernel/msm-4.9 - Gitiles

 /*
  *  linux/arch/arm/mach-omap1/clock.c
  *
  *  Copyright (C) 2004 - 2005, 2009-2010 Nokia Corporation
  *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
  *
  *  Modified to use omap shared clock framework by
  *  Tony Lindgren <tony@atomide.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/kernel.h>
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>

 #include <asm/mach-types.h>

 #include <plat/cpu.h>
 #include <plat/usb.h>
 #include <plat/clock.h>
 #include <plat/sram.h>
 #include <plat/clkdev_omap.h>

 #include <mach/hardware.h>

 #include "iomap.h"
 #include "clock.h"
 #include "opp.h"

 __u32 arm_idlect1_mask;
 struct clk *api_ck_p, *ck_dpll1_p, *ck_ref_p;

 /*
  * Omap1 specific clock functions
  */

 unsigned long omap1_uart_recalc(struct clk *clk)
 {
 	unsigned int val = __raw_readl(clk->enable_reg);
 	return val & clk->enable_bit ? 48000000 : 12000000;
 }

 unsigned long omap1_sossi_recalc(struct clk *clk)
 {
 	u32 div = omap_readl(MOD_CONF_CTRL_1);

 	div = (div >> 17) & 0x7;
 	div++;

 	return clk->parent->rate / div;
 }

 static void omap1_clk_allow_idle(struct clk *clk)
 {
 	struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;

 	if (!(clk->flags & CLOCK_IDLE_CONTROL))
 		return;

 	if (iclk->no_idle_count > 0 && !(--iclk->no_idle_count))
 		arm_idlect1_mask |= 1 << iclk->idlect_shift;
 }

 static void omap1_clk_deny_idle(struct clk *clk)
 {
 	struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;

 	if (!(clk->flags & CLOCK_IDLE_CONTROL))
 		return;

 	if (iclk->no_idle_count++ == 0)
 		arm_idlect1_mask &= ~(1 << iclk->idlect_shift);
 }

 static __u16 verify_ckctl_value(__u16 newval)
 {
 	/* This function checks for following limitations set
 	 * by the hardware (all conditions must be true):
 	 * DSPMMU_CK == DSP_CK  or  DSPMMU_CK == DSP_CK/2
 	 * ARM_CK >= TC_CK
 	 * DSP_CK >= TC_CK
 	 * DSPMMU_CK >= TC_CK
 	 *
 	 * In addition following rules are enforced:
 	 * LCD_CK <= TC_CK
 	 * ARMPER_CK <= TC_CK
 	 *
 	 * However, maximum frequencies are not checked for!
 	 */
 	__u8 per_exp;
 	__u8 lcd_exp;
 	__u8 arm_exp;
 	__u8 dsp_exp;
 	__u8 tc_exp;
 	__u8 dspmmu_exp;

 	per_exp = (newval >> CKCTL_PERDIV_OFFSET) & 3;
 	lcd_exp = (newval >> CKCTL_LCDDIV_OFFSET) & 3;
 	arm_exp = (newval >> CKCTL_ARMDIV_OFFSET) & 3;
 	dsp_exp = (newval >> CKCTL_DSPDIV_OFFSET) & 3;
 	tc_exp = (newval >> CKCTL_TCDIV_OFFSET) & 3;
 	dspmmu_exp = (newval >> CKCTL_DSPMMUDIV_OFFSET) & 3;

 	if (dspmmu_exp < dsp_exp)
 		dspmmu_exp = dsp_exp;
 	if (dspmmu_exp > dsp_exp+1)
 		dspmmu_exp = dsp_exp+1;
 	if (tc_exp < arm_exp)
 		tc_exp = arm_exp;
 	if (tc_exp < dspmmu_exp)
 		tc_exp = dspmmu_exp;
 	if (tc_exp > lcd_exp)
 		lcd_exp = tc_exp;
 	if (tc_exp > per_exp)
 		per_exp = tc_exp;

 	newval &= 0xf000;
 	newval |= per_exp << CKCTL_PERDIV_OFFSET;
 	newval |= lcd_exp << CKCTL_LCDDIV_OFFSET;
 	newval |= arm_exp << CKCTL_ARMDIV_OFFSET;
 	newval |= dsp_exp << CKCTL_DSPDIV_OFFSET;
 	newval |= tc_exp << CKCTL_TCDIV_OFFSET;
 	newval |= dspmmu_exp << CKCTL_DSPMMUDIV_OFFSET;

 	return newval;
 }

 static int calc_dsor_exp(struct clk *clk, unsigned long rate)
 {
 	/* Note: If target frequency is too low, this function will return 4,
 	 * which is invalid value. Caller must check for this value and act
 	 * accordingly.
 	 *
 	 * Note: This function does not check for following limitations set
 	 * by the hardware (all conditions must be true):
 	 * DSPMMU_CK == DSP_CK  or  DSPMMU_CK == DSP_CK/2
 	 * ARM_CK >= TC_CK
 	 * DSP_CK >= TC_CK
 	 * DSPMMU_CK >= TC_CK
 	 */
 	unsigned long realrate;
 	struct clk * parent;
 	unsigned  dsor_exp;

 	parent = clk->parent;
 	if (unlikely(parent == NULL))
 		return -EIO;

 	realrate = parent->rate;
 	for (dsor_exp=0; dsor_exp<4; dsor_exp++) {
 		if (realrate <= rate)
 			break;

 		realrate /= 2;
 	}

 	return dsor_exp;
 }

 unsigned long omap1_ckctl_recalc(struct clk *clk)
 {
 	/* Calculate divisor encoded as 2-bit exponent */
 	int dsor = 1 << (3 & (omap_readw(ARM_CKCTL) >> clk->rate_offset));

 	return clk->parent->rate / dsor;
 }

 unsigned long omap1_ckctl_recalc_dsp_domain(struct clk *clk)
 {
 	int dsor;

 	/* Calculate divisor encoded as 2-bit exponent
 	 *
 	 * The clock control bits are in DSP domain,
 	 * so api_ck is needed for access.
 	 * Note that DSP_CKCTL virt addr = phys addr, so
 	 * we must use __raw_readw() instead of omap_readw().
 	 */
 	omap1_clk_enable(api_ck_p);
 	dsor = 1 << (3 & (__raw_readw(DSP_CKCTL) >> clk->rate_offset));
 	omap1_clk_disable(api_ck_p);

 	return clk->parent->rate / dsor;
 }

 /* MPU virtual clock functions */
 int omap1_select_table_rate(struct clk *clk, unsigned long rate)
 {
 	/* Find the highest supported frequency <= rate and switch to it */
 	struct mpu_rate * ptr;
 	unsigned long ref_rate;

 	ref_rate = ck_ref_p->rate;

 	for (ptr = omap1_rate_table; ptr->rate; ptr++) {
 		if (!(ptr->flags & cpu_mask))
 			continue;

 		if (ptr->xtal != ref_rate)
 			continue;

 		/* Can check only after xtal frequency check */
 		if (ptr->rate <= rate)
 			break;
 	}

 	if (!ptr->rate)
 		return -EINVAL;

 	/*
 	 * In most cases we should not need to reprogram DPLL.
 	 * Reprogramming the DPLL is tricky, it must be done from SRAM.
 	 */
 	omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val);

 	/* XXX Do we need to recalculate the tree below DPLL1 at this point? */
 	ck_dpll1_p->rate = ptr->pll_rate;

 	return 0;
 }

 int omap1_clk_set_rate_dsp_domain(struct clk *clk, unsigned long rate)
 {
 	int dsor_exp;
 	u16 regval;

 	dsor_exp = calc_dsor_exp(clk, rate);
 	if (dsor_exp > 3)
 		dsor_exp = -EINVAL;
 	if (dsor_exp < 0)
 		return dsor_exp;

 	regval = __raw_readw(DSP_CKCTL);
 	regval &= ~(3 << clk->rate_offset);
 	regval |= dsor_exp << clk->rate_offset;
 	__raw_writew(regval, DSP_CKCTL);
 	clk->rate = clk->parent->rate / (1 << dsor_exp);

 	return 0;
 }

 long omap1_clk_round_rate_ckctl_arm(struct clk *clk, unsigned long rate)
 {
 	int dsor_exp = calc_dsor_exp(clk, rate);
 	if (dsor_exp < 0)
 		return dsor_exp;
 	if (dsor_exp > 3)
 		dsor_exp = 3;
 	return clk->parent->rate / (1 << dsor_exp);
 }

 int omap1_clk_set_rate_ckctl_arm(struct clk *clk, unsigned long rate)
 {
 	int dsor_exp;
 	u16 regval;

 	dsor_exp = calc_dsor_exp(clk, rate);
 	if (dsor_exp > 3)
 		dsor_exp = -EINVAL;
 	if (dsor_exp < 0)
 		return dsor_exp;

 	regval = omap_readw(ARM_CKCTL);
 	regval &= ~(3 << clk->rate_offset);
 	regval |= dsor_exp << clk->rate_offset;
 	regval = verify_ckctl_value(regval);
 	omap_writew(regval, ARM_CKCTL);
 	clk->rate = clk->parent->rate / (1 << dsor_exp);
 	return 0;
 }

 long omap1_round_to_table_rate(struct clk *clk, unsigned long rate)
 {
 	/* Find the highest supported frequency <= rate */
 	struct mpu_rate * ptr;
 	long highest_rate;
 	unsigned long ref_rate;

 	ref_rate = ck_ref_p->rate;

 	highest_rate = -EINVAL;

 	for (ptr = omap1_rate_table; ptr->rate; ptr++) {
 		if (!(ptr->flags & cpu_mask))
 			continue;

 		if (ptr->xtal != ref_rate)
 			continue;

 		highest_rate = ptr->rate;

 		/* Can check only after xtal frequency check */
 		if (ptr->rate <= rate)
 			break;
 	}

 	return highest_rate;
 }

 static unsigned calc_ext_dsor(unsigned long rate)
 {
 	unsigned dsor;

 	/* MCLK and BCLK divisor selection is not linear:
 	 * freq = 96MHz / dsor
 	 *
 	 * RATIO_SEL range: dsor <-> RATIO_SEL
 	 * 0..6: (RATIO_SEL+2) <-> (dsor-2)
 	 * 6..48:  (8+(RATIO_SEL-6)*2) <-> ((dsor-8)/2+6)
 	 * Minimum dsor is 2 and maximum is 96. Odd divisors starting from 9
 	 * can not be used.
 	 */
 	for (dsor = 2; dsor < 96; ++dsor) {
 		if ((dsor & 1) && dsor > 8)
 			continue;
 		if (rate >= 96000000 / dsor)
 			break;
 	}
 	return dsor;
 }

 /* XXX Only needed on 1510 */
 int omap1_set_uart_rate(struct clk *clk, unsigned long rate)
 {
 	unsigned int val;

 	val = __raw_readl(clk->enable_reg);
 	if (rate == 12000000)
 		val &= ~(1 << clk->enable_bit);
 	else if (rate == 48000000)
 		val |= (1 << clk->enable_bit);
 	else
 		return -EINVAL;
 	__raw_writel(val, clk->enable_reg);
 	clk->rate = rate;

 	return 0;
 }

 /* External clock (MCLK & BCLK) functions */
 int omap1_set_ext_clk_rate(struct clk *clk, unsigned long rate)
 {
 	unsigned dsor;
 	__u16 ratio_bits;

 	dsor = calc_ext_dsor(rate);
 	clk->rate = 96000000 / dsor;
 	if (dsor > 8)
 		ratio_bits = ((dsor - 8) / 2 + 6) << 2;
 	else
 		ratio_bits = (dsor - 2) << 2;

 	ratio_bits |= __raw_readw(clk->enable_reg) & ~0xfd;
 	__raw_writew(ratio_bits, clk->enable_reg);

 	return 0;
 }

 int omap1_set_sossi_rate(struct clk *clk, unsigned long rate)
 {
 	u32 l;
 	int div;
 	unsigned long p_rate;

 	p_rate = clk->parent->rate;
 	/* Round towards slower frequency */
 	div = (p_rate + rate - 1) / rate;
 	div--;
 	if (div < 0 || div > 7)
 		return -EINVAL;

 	l = omap_readl(MOD_CONF_CTRL_1);
 	l &= ~(7 << 17);
 	l |= div << 17;
 	omap_writel(l, MOD_CONF_CTRL_1);

 	clk->rate = p_rate / (div + 1);

 	return 0;
 }

 long omap1_round_ext_clk_rate(struct clk *clk, unsigned long rate)
 {
 	return 96000000 / calc_ext_dsor(rate);
 }

 void omap1_init_ext_clk(struct clk *clk)
 {
 	unsigned dsor;
 	__u16 ratio_bits;

 	/* Determine current rate and ensure clock is based on 96MHz APLL */
 	ratio_bits = __raw_readw(clk->enable_reg) & ~1;
 	__raw_writew(ratio_bits, clk->enable_reg);

 	ratio_bits = (ratio_bits & 0xfc) >> 2;
 	if (ratio_bits > 6)
 		dsor = (ratio_bits - 6) * 2 + 8;
 	else
 		dsor = ratio_bits + 2;

 	clk-> rate = 96000000 / dsor;
 }

 int omap1_clk_enable(struct clk *clk)
 {
 	int ret = 0;

 	if (clk->usecount++ == 0) {
 		if (clk->parent) {
 			ret = omap1_clk_enable(clk->parent);
 			if (ret)
 				goto err;

 			if (clk->flags & CLOCK_NO_IDLE_PARENT)
 				omap1_clk_deny_idle(clk->parent);
 		}

 		ret = clk->ops->enable(clk);
 		if (ret) {
 			if (clk->parent)
 				omap1_clk_disable(clk->parent);
 			goto err;
 		}
 	}
 	return ret;

 err:
 	clk->usecount--;
 	return ret;
 }

 void omap1_clk_disable(struct clk *clk)
 {
 	if (clk->usecount > 0 && !(--clk->usecount)) {
 		clk->ops->disable(clk);
 		if (likely(clk->parent)) {
 			omap1_clk_disable(clk->parent);
 			if (clk->flags & CLOCK_NO_IDLE_PARENT)
 				omap1_clk_allow_idle(clk->parent);
 		}
 	}
 }

 static int omap1_clk_enable_generic(struct clk *clk)
 {
 	__u16 regval16;
 	__u32 regval32;

 	if (unlikely(clk->enable_reg == NULL)) {
 		printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
 		       clk->name);
 		return -EINVAL;
 	}

 	if (clk->flags & ENABLE_REG_32BIT) {
 		regval32 = __raw_readl(clk->enable_reg);
 		regval32 |= (1 << clk->enable_bit);
 		__raw_writel(regval32, clk->enable_reg);
 	} else {
 		regval16 = __raw_readw(clk->enable_reg);
 		regval16 |= (1 << clk->enable_bit);
 		__raw_writew(regval16, clk->enable_reg);
 	}

 	return 0;
 }

 static void omap1_clk_disable_generic(struct clk *clk)
 {
 	__u16 regval16;
 	__u32 regval32;

 	if (clk->enable_reg == NULL)
 		return;

 	if (clk->flags & ENABLE_REG_32BIT) {
 		regval32 = __raw_readl(clk->enable_reg);
 		regval32 &= ~(1 << clk->enable_bit);
 		__raw_writel(regval32, clk->enable_reg);
 	} else {
 		regval16 = __raw_readw(clk->enable_reg);
 		regval16 &= ~(1 << clk->enable_bit);
 		__raw_writew(regval16, clk->enable_reg);
 	}
 }

 const struct clkops clkops_generic = {
 	.enable		= omap1_clk_enable_generic,
 	.disable	= omap1_clk_disable_generic,
 };

 static int omap1_clk_enable_dsp_domain(struct clk *clk)
 {
 	int retval;

 	retval = omap1_clk_enable(api_ck_p);
 	if (!retval) {
 		retval = omap1_clk_enable_generic(clk);
 		omap1_clk_disable(api_ck_p);
 	}

 	return retval;
 }

 static void omap1_clk_disable_dsp_domain(struct clk *clk)
 {
 	if (omap1_clk_enable(api_ck_p) == 0) {
 		omap1_clk_disable_generic(clk);
 		omap1_clk_disable(api_ck_p);
 	}
 }

 const struct clkops clkops_dspck = {
 	.enable		= omap1_clk_enable_dsp_domain,
 	.disable	= omap1_clk_disable_dsp_domain,
 };

 /* XXX SYSC register handling does not belong in the clock framework */
 static int omap1_clk_enable_uart_functional_16xx(struct clk *clk)
 {
 	int ret;
 	struct uart_clk *uclk;

 	ret = omap1_clk_enable_generic(clk);
 	if (ret == 0) {
 		/* Set smart idle acknowledgement mode */
 		uclk = (struct uart_clk *)clk;
 		omap_writeb((omap_readb(uclk->sysc_addr) & ~0x10) | 8,
 			    uclk->sysc_addr);
 	}

 	return ret;
 }

 /* XXX SYSC register handling does not belong in the clock framework */
 static void omap1_clk_disable_uart_functional_16xx(struct clk *clk)
 {
 	struct uart_clk *uclk;

 	/* Set force idle acknowledgement mode */
 	uclk = (struct uart_clk *)clk;
 	omap_writeb((omap_readb(uclk->sysc_addr) & ~0x18), uclk->sysc_addr);

 	omap1_clk_disable_generic(clk);
 }

 /* XXX SYSC register handling does not belong in the clock framework */
 const struct clkops clkops_uart_16xx = {
 	.enable		= omap1_clk_enable_uart_functional_16xx,
 	.disable	= omap1_clk_disable_uart_functional_16xx,
 };

 long omap1_clk_round_rate(struct clk *clk, unsigned long rate)
 {
 	if (clk->round_rate != NULL)
 		return clk->round_rate(clk, rate);

 	return clk->rate;
 }

 int omap1_clk_set_rate(struct clk *clk, unsigned long rate)
 {
 	int  ret = -EINVAL;

 	if (clk->set_rate)
 		ret = clk->set_rate(clk, rate);
 	return ret;
 }

 /*
  * Omap1 clock reset and init functions
  */

 #ifdef CONFIG_OMAP_RESET_CLOCKS

 void omap1_clk_disable_unused(struct clk *clk)
 {
 	__u32 regval32;

 	/* Clocks in the DSP domain need api_ck. Just assume bootloader
 	 * has not enabled any DSP clocks */
 	if (clk->enable_reg == DSP_IDLECT2) {
 		printk(KERN_INFO "Skipping reset check for DSP domain "
 		       "clock \"%s\"\n", clk->name);
 		return;
 	}

 	/* Is the clock already disabled? */
 	if (clk->flags & ENABLE_REG_32BIT)
 		regval32 = __raw_readl(clk->enable_reg);
 	else
 		regval32 = __raw_readw(clk->enable_reg);

 	if ((regval32 & (1 << clk->enable_bit)) == 0)
 		return;

 	printk(KERN_INFO "Disabling unused clock \"%s\"... ", clk->name);
 	clk->ops->disable(clk);
 	printk(" done\n");
 }

 #endif
	/*
	* linux/arch/arm/mach-omap1/clock.c
	*
	* Copyright (C) 2004 - 2005, 2009-2010 Nokia Corporation
	* Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
	*
	* Modified to use omap shared clock framework by
	* Tony Lindgren <tony@atomide.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/kernel.h>
	#include <linux/list.h>
	#include <linux/errno.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/clk.h>
	#include <linux/clkdev.h>

	#include <asm/mach-types.h>

	#include <plat/cpu.h>
	#include <plat/usb.h>
	#include <plat/clock.h>
	#include <plat/sram.h>
	#include <plat/clkdev_omap.h>

	#include <mach/hardware.h>

	#include "iomap.h"
	#include "clock.h"
	#include "opp.h"

	__u32 arm_idlect1_mask;
	struct clk api_ck_p, ck_dpll1_p, *ck_ref_p;

	/*
	* Omap1 specific clock functions
	*/

	unsigned long omap1_uart_recalc(struct clk *clk)
	{
	unsigned int val = __raw_readl(clk->enable_reg);
	return val & clk->enable_bit ? 48000000 : 12000000;
	}

	unsigned long omap1_sossi_recalc(struct clk *clk)
	{
	u32 div = omap_readl(MOD_CONF_CTRL_1);

	div = (div >> 17) & 0x7;
	div++;

	return clk->parent->rate / div;
	}

	static void omap1_clk_allow_idle(struct clk *clk)
	{
	struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;

	if (!(clk->flags & CLOCK_IDLE_CONTROL))
	return;

	if (iclk->no_idle_count > 0 && !(--iclk->no_idle_count))
	arm_idlect1_mask \|= 1 << iclk->idlect_shift;
	}

	static void omap1_clk_deny_idle(struct clk *clk)
	{
	struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;

	if (!(clk->flags & CLOCK_IDLE_CONTROL))
	return;

	if (iclk->no_idle_count++ == 0)
	arm_idlect1_mask &= ~(1 << iclk->idlect_shift);
	}

	static __u16 verify_ckctl_value(__u16 newval)
	{
	/* This function checks for following limitations set
	* by the hardware (all conditions must be true):
	* DSPMMU_CK == DSP_CK or DSPMMU_CK == DSP_CK/2
	* ARM_CK >= TC_CK
	* DSP_CK >= TC_CK
	* DSPMMU_CK >= TC_CK
	*
	* In addition following rules are enforced:
	* LCD_CK <= TC_CK
	* ARMPER_CK <= TC_CK
	*
	* However, maximum frequencies are not checked for!
	*/
	__u8 per_exp;
	__u8 lcd_exp;
	__u8 arm_exp;
	__u8 dsp_exp;
	__u8 tc_exp;
	__u8 dspmmu_exp;

	per_exp = (newval >> CKCTL_PERDIV_OFFSET) & 3;
	lcd_exp = (newval >> CKCTL_LCDDIV_OFFSET) & 3;
	arm_exp = (newval >> CKCTL_ARMDIV_OFFSET) & 3;
	dsp_exp = (newval >> CKCTL_DSPDIV_OFFSET) & 3;
	tc_exp = (newval >> CKCTL_TCDIV_OFFSET) & 3;
	dspmmu_exp = (newval >> CKCTL_DSPMMUDIV_OFFSET) & 3;

	if (dspmmu_exp < dsp_exp)
	dspmmu_exp = dsp_exp;
	if (dspmmu_exp > dsp_exp+1)
	dspmmu_exp = dsp_exp+1;
	if (tc_exp < arm_exp)
	tc_exp = arm_exp;
	if (tc_exp < dspmmu_exp)
	tc_exp = dspmmu_exp;
	if (tc_exp > lcd_exp)
	lcd_exp = tc_exp;
	if (tc_exp > per_exp)
	per_exp = tc_exp;

	newval &= 0xf000;
	newval \|= per_exp << CKCTL_PERDIV_OFFSET;
	newval \|= lcd_exp << CKCTL_LCDDIV_OFFSET;
	newval \|= arm_exp << CKCTL_ARMDIV_OFFSET;
	newval \|= dsp_exp << CKCTL_DSPDIV_OFFSET;
	newval \|= tc_exp << CKCTL_TCDIV_OFFSET;
	newval \|= dspmmu_exp << CKCTL_DSPMMUDIV_OFFSET;

	return newval;
	}

	static int calc_dsor_exp(struct clk *clk, unsigned long rate)
	{
	/* Note: If target frequency is too low, this function will return 4,
	* which is invalid value. Caller must check for this value and act
	* accordingly.
	*
	* Note: This function does not check for following limitations set
	* by the hardware (all conditions must be true):
	* DSPMMU_CK == DSP_CK or DSPMMU_CK == DSP_CK/2
	* ARM_CK >= TC_CK
	* DSP_CK >= TC_CK
	* DSPMMU_CK >= TC_CK
	*/
	unsigned long realrate;
	struct clk * parent;
	unsigned dsor_exp;

	parent = clk->parent;
	if (unlikely(parent == NULL))
	return -EIO;

	realrate = parent->rate;
	for (dsor_exp=0; dsor_exp<4; dsor_exp++) {
	if (realrate <= rate)
	break;

	realrate /= 2;
	}

	return dsor_exp;
	}

	unsigned long omap1_ckctl_recalc(struct clk *clk)
	{
	/* Calculate divisor encoded as 2-bit exponent */
	int dsor = 1 << (3 & (omap_readw(ARM_CKCTL) >> clk->rate_offset));

	return clk->parent->rate / dsor;
	}

	unsigned long omap1_ckctl_recalc_dsp_domain(struct clk *clk)
	{
	int dsor;

	/* Calculate divisor encoded as 2-bit exponent
	*
	* The clock control bits are in DSP domain,
	* so api_ck is needed for access.
	* Note that DSP_CKCTL virt addr = phys addr, so
	* we must use __raw_readw() instead of omap_readw().
	*/
	omap1_clk_enable(api_ck_p);
	dsor = 1 << (3 & (__raw_readw(DSP_CKCTL) >> clk->rate_offset));
	omap1_clk_disable(api_ck_p);

	return clk->parent->rate / dsor;
	}

	/* MPU virtual clock functions */
	int omap1_select_table_rate(struct clk *clk, unsigned long rate)
	{
	/* Find the highest supported frequency <= rate and switch to it */
	struct mpu_rate * ptr;
	unsigned long ref_rate;

	ref_rate = ck_ref_p->rate;

	for (ptr = omap1_rate_table; ptr->rate; ptr++) {
	if (!(ptr->flags & cpu_mask))
	continue;

	if (ptr->xtal != ref_rate)
	continue;

	/* Can check only after xtal frequency check */
	if (ptr->rate <= rate)
	break;
	}

	if (!ptr->rate)
	return -EINVAL;

	/*
	* In most cases we should not need to reprogram DPLL.
	* Reprogramming the DPLL is tricky, it must be done from SRAM.
	*/
	omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val);

	/* XXX Do we need to recalculate the tree below DPLL1 at this point? */
	ck_dpll1_p->rate = ptr->pll_rate;

	return 0;
	}

	int omap1_clk_set_rate_dsp_domain(struct clk *clk, unsigned long rate)
	{
	int dsor_exp;
	u16 regval;

	dsor_exp = calc_dsor_exp(clk, rate);
	if (dsor_exp > 3)
	dsor_exp = -EINVAL;
	if (dsor_exp < 0)
	return dsor_exp;

	regval = __raw_readw(DSP_CKCTL);
	regval &= ~(3 << clk->rate_offset);
	regval \|= dsor_exp << clk->rate_offset;
	__raw_writew(regval, DSP_CKCTL);
	clk->rate = clk->parent->rate / (1 << dsor_exp);

	return 0;
	}

	long omap1_clk_round_rate_ckctl_arm(struct clk *clk, unsigned long rate)
	{
	int dsor_exp = calc_dsor_exp(clk, rate);
	if (dsor_exp < 0)
	return dsor_exp;
	if (dsor_exp > 3)
	dsor_exp = 3;
	return clk->parent->rate / (1 << dsor_exp);
	}

	int omap1_clk_set_rate_ckctl_arm(struct clk *clk, unsigned long rate)
	{
	int dsor_exp;
	u16 regval;

	dsor_exp = calc_dsor_exp(clk, rate);
	if (dsor_exp > 3)
	dsor_exp = -EINVAL;
	if (dsor_exp < 0)
	return dsor_exp;

	regval = omap_readw(ARM_CKCTL);
	regval &= ~(3 << clk->rate_offset);
	regval \|= dsor_exp << clk->rate_offset;
	regval = verify_ckctl_value(regval);
	omap_writew(regval, ARM_CKCTL);
	clk->rate = clk->parent->rate / (1 << dsor_exp);
	return 0;
	}

	long omap1_round_to_table_rate(struct clk *clk, unsigned long rate)
	{
	/* Find the highest supported frequency <= rate */
	struct mpu_rate * ptr;
	long highest_rate;
	unsigned long ref_rate;

	ref_rate = ck_ref_p->rate;

	highest_rate = -EINVAL;

	for (ptr = omap1_rate_table; ptr->rate; ptr++) {
	if (!(ptr->flags & cpu_mask))
	continue;

	if (ptr->xtal != ref_rate)
	continue;

	highest_rate = ptr->rate;

	/* Can check only after xtal frequency check */
	if (ptr->rate <= rate)
	break;
	}

	return highest_rate;
	}

	static unsigned calc_ext_dsor(unsigned long rate)
	{
	unsigned dsor;

	/* MCLK and BCLK divisor selection is not linear:
	* freq = 96MHz / dsor
	*
	* RATIO_SEL range: dsor <-> RATIO_SEL
	* 0..6: (RATIO_SEL+2) <-> (dsor-2)
	* 6..48: (8+(RATIO_SEL-6)*2) <-> ((dsor-8)/2+6)
	* Minimum dsor is 2 and maximum is 96. Odd divisors starting from 9
	* can not be used.
	*/
	for (dsor = 2; dsor < 96; ++dsor) {
	if ((dsor & 1) && dsor > 8)
	continue;
	if (rate >= 96000000 / dsor)
	break;
	}
	return dsor;
	}

	/* XXX Only needed on 1510 */
	int omap1_set_uart_rate(struct clk *clk, unsigned long rate)
	{
	unsigned int val;

	val = __raw_readl(clk->enable_reg);
	if (rate == 12000000)
	val &= ~(1 << clk->enable_bit);
	else if (rate == 48000000)
	val \|= (1 << clk->enable_bit);
	else
	return -EINVAL;
	__raw_writel(val, clk->enable_reg);
	clk->rate = rate;

	return 0;
	}

	/* External clock (MCLK & BCLK) functions */
	int omap1_set_ext_clk_rate(struct clk *clk, unsigned long rate)
	{
	unsigned dsor;
	__u16 ratio_bits;

	dsor = calc_ext_dsor(rate);
	clk->rate = 96000000 / dsor;
	if (dsor > 8)
	ratio_bits = ((dsor - 8) / 2 + 6) << 2;
	else
	ratio_bits = (dsor - 2) << 2;

	ratio_bits \|= __raw_readw(clk->enable_reg) & ~0xfd;
	__raw_writew(ratio_bits, clk->enable_reg);

	return 0;
	}

	int omap1_set_sossi_rate(struct clk *clk, unsigned long rate)
	{
	u32 l;
	int div;
	unsigned long p_rate;

	p_rate = clk->parent->rate;
	/* Round towards slower frequency */
	div = (p_rate + rate - 1) / rate;
	div--;
	if (div < 0 \|\| div > 7)
	return -EINVAL;

	l = omap_readl(MOD_CONF_CTRL_1);
	l &= ~(7 << 17);
	l \|= div << 17;
	omap_writel(l, MOD_CONF_CTRL_1);

	clk->rate = p_rate / (div + 1);

	return 0;
	}

	long omap1_round_ext_clk_rate(struct clk *clk, unsigned long rate)
	{
	return 96000000 / calc_ext_dsor(rate);
	}

	void omap1_init_ext_clk(struct clk *clk)
	{
	unsigned dsor;
	__u16 ratio_bits;

	/* Determine current rate and ensure clock is based on 96MHz APLL */
	ratio_bits = __raw_readw(clk->enable_reg) & ~1;
	__raw_writew(ratio_bits, clk->enable_reg);

	ratio_bits = (ratio_bits & 0xfc) >> 2;
	if (ratio_bits > 6)
	dsor = (ratio_bits - 6) * 2 + 8;
	else
	dsor = ratio_bits + 2;

	clk-> rate = 96000000 / dsor;
	}

	int omap1_clk_enable(struct clk *clk)
	{
	int ret = 0;

	if (clk->usecount++ == 0) {
	if (clk->parent) {
	ret = omap1_clk_enable(clk->parent);
	if (ret)
	goto err;

	if (clk->flags & CLOCK_NO_IDLE_PARENT)
	omap1_clk_deny_idle(clk->parent);
	}

	ret = clk->ops->enable(clk);
	if (ret) {
	if (clk->parent)
	omap1_clk_disable(clk->parent);
	goto err;
	}
	}
	return ret;

	err:
	clk->usecount--;
	return ret;
	}

	void omap1_clk_disable(struct clk *clk)
	{
	if (clk->usecount > 0 && !(--clk->usecount)) {
	clk->ops->disable(clk);
	if (likely(clk->parent)) {
	omap1_clk_disable(clk->parent);
	if (clk->flags & CLOCK_NO_IDLE_PARENT)
	omap1_clk_allow_idle(clk->parent);
	}
	}
	}

	static int omap1_clk_enable_generic(struct clk *clk)
	{
	__u16 regval16;
	__u32 regval32;

	if (unlikely(clk->enable_reg == NULL)) {
	printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
	clk->name);
	return -EINVAL;
	}

	if (clk->flags & ENABLE_REG_32BIT) {
	regval32 = __raw_readl(clk->enable_reg);
	regval32 \|= (1 << clk->enable_bit);
	__raw_writel(regval32, clk->enable_reg);
	} else {
	regval16 = __raw_readw(clk->enable_reg);
	regval16 \|= (1 << clk->enable_bit);
	__raw_writew(regval16, clk->enable_reg);
	}

	return 0;
	}

	static void omap1_clk_disable_generic(struct clk *clk)
	{
	__u16 regval16;
	__u32 regval32;

	if (clk->enable_reg == NULL)
	return;

	if (clk->flags & ENABLE_REG_32BIT) {
	regval32 = __raw_readl(clk->enable_reg);
	regval32 &= ~(1 << clk->enable_bit);
	__raw_writel(regval32, clk->enable_reg);
	} else {
	regval16 = __raw_readw(clk->enable_reg);
	regval16 &= ~(1 << clk->enable_bit);
	__raw_writew(regval16, clk->enable_reg);
	}
	}

	const struct clkops clkops_generic = {
	.enable = omap1_clk_enable_generic,
	.disable = omap1_clk_disable_generic,
	};

	static int omap1_clk_enable_dsp_domain(struct clk *clk)
	{
	int retval;

	retval = omap1_clk_enable(api_ck_p);
	if (!retval) {
	retval = omap1_clk_enable_generic(clk);
	omap1_clk_disable(api_ck_p);
	}

	return retval;
	}

	static void omap1_clk_disable_dsp_domain(struct clk *clk)
	{
	if (omap1_clk_enable(api_ck_p) == 0) {
	omap1_clk_disable_generic(clk);
	omap1_clk_disable(api_ck_p);
	}
	}

	const struct clkops clkops_dspck = {
	.enable = omap1_clk_enable_dsp_domain,
	.disable = omap1_clk_disable_dsp_domain,
	};

	/* XXX SYSC register handling does not belong in the clock framework */
	static int omap1_clk_enable_uart_functional_16xx(struct clk *clk)
	{
	int ret;
	struct uart_clk *uclk;

	ret = omap1_clk_enable_generic(clk);
	if (ret == 0) {
	/* Set smart idle acknowledgement mode */
	uclk = (struct uart_clk *)clk;
	omap_writeb((omap_readb(uclk->sysc_addr) & ~0x10) \| 8,
	uclk->sysc_addr);
	}

	return ret;
	}

	/* XXX SYSC register handling does not belong in the clock framework */
	static void omap1_clk_disable_uart_functional_16xx(struct clk *clk)
	{
	struct uart_clk *uclk;

	/* Set force idle acknowledgement mode */
	uclk = (struct uart_clk *)clk;
	omap_writeb((omap_readb(uclk->sysc_addr) & ~0x18), uclk->sysc_addr);

	omap1_clk_disable_generic(clk);
	}

	/* XXX SYSC register handling does not belong in the clock framework */
	const struct clkops clkops_uart_16xx = {
	.enable = omap1_clk_enable_uart_functional_16xx,
	.disable = omap1_clk_disable_uart_functional_16xx,
	};

	long omap1_clk_round_rate(struct clk *clk, unsigned long rate)
	{
	if (clk->round_rate != NULL)
	return clk->round_rate(clk, rate);

	return clk->rate;
	}

	int omap1_clk_set_rate(struct clk *clk, unsigned long rate)
	{
	int ret = -EINVAL;

	if (clk->set_rate)
	ret = clk->set_rate(clk, rate);
	return ret;
	}

	/*
	* Omap1 clock reset and init functions
	*/

	#ifdef CONFIG_OMAP_RESET_CLOCKS

	void omap1_clk_disable_unused(struct clk *clk)
	{
	__u32 regval32;

	/* Clocks in the DSP domain need api_ck. Just assume bootloader
	* has not enabled any DSP clocks */
	if (clk->enable_reg == DSP_IDLECT2) {
	printk(KERN_INFO "Skipping reset check for DSP domain "
	"clock \"%s\"\n", clk->name);
	return;
	}

	/* Is the clock already disabled? */
	if (clk->flags & ENABLE_REG_32BIT)
	regval32 = __raw_readl(clk->enable_reg);
	else
	regval32 = __raw_readw(clk->enable_reg);

	if ((regval32 & (1 << clk->enable_bit)) == 0)
	return;

	printk(KERN_INFO "Disabling unused clock \"%s\"... ", clk->name);
	clk->ops->disable(clk);
	printk(" done\n");
	}

	#endif