arch/arm/mach-omap2/cm2xxx.c - kernel/mindspeed - Git at Google

 /*
  * OMAP2xxx CM module functions
  *
  * Copyright (C) 2009 Nokia Corporation
  * Copyright (C) 2008-2010, 2012 Texas Instruments, Inc.
  * Paul Walmsley
  * Rajendra Nayak <rnayak@ti.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/types.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/io.h>

 #include "prm2xxx.h"
 #include "cm.h"
 #include "cm2xxx.h"
 #include "cm-regbits-24xx.h"
 #include "clockdomain.h"

 /* CM_AUTOIDLE_PLL.AUTO_* bit values for DPLLs */
 #define DPLL_AUTOIDLE_DISABLE				0x0
 #define OMAP2XXX_DPLL_AUTOIDLE_LOW_POWER_STOP		0x3

 /* CM_AUTOIDLE_PLL.AUTO_* bit values for APLLs (OMAP2xxx only) */
 #define OMAP2XXX_APLL_AUTOIDLE_DISABLE			0x0
 #define OMAP2XXX_APLL_AUTOIDLE_LOW_POWER_STOP		0x3

 /* CM_IDLEST_PLL bit value offset for APLLs (OMAP2xxx only) */
 #define EN_APLL_LOCKED					3

 static const u8 omap2xxx_cm_idlest_offs[] = {
 	CM_IDLEST1, CM_IDLEST2, OMAP2430_CM_IDLEST3, OMAP24XX_CM_IDLEST4
 };

 /*
  *
  */

 static void _write_clktrctrl(u8 c, s16 module, u32 mask)
 {
 	u32 v;

 	v = omap2_cm_read_mod_reg(module, OMAP2_CM_CLKSTCTRL);
 	v &= ~mask;
 	v |= c << __ffs(mask);
 	omap2_cm_write_mod_reg(v, module, OMAP2_CM_CLKSTCTRL);
 }

 static bool omap2xxx_cm_is_clkdm_in_hwsup(s16 module, u32 mask)
 {
 	u32 v;

 	v = omap2_cm_read_mod_reg(module, OMAP2_CM_CLKSTCTRL);
 	v &= mask;
 	v >>= __ffs(mask);

 	return (v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO) ? 1 : 0;
 }

 static void omap2xxx_cm_clkdm_enable_hwsup(s16 module, u32 mask)
 {
 	_write_clktrctrl(OMAP24XX_CLKSTCTRL_ENABLE_AUTO, module, mask);
 }

 static void omap2xxx_cm_clkdm_disable_hwsup(s16 module, u32 mask)
 {
 	_write_clktrctrl(OMAP24XX_CLKSTCTRL_DISABLE_AUTO, module, mask);
 }

 /*
  * DPLL autoidle control
  */

 static void _omap2xxx_set_dpll_autoidle(u8 m)
 {
 	u32 v;

 	v = omap2_cm_read_mod_reg(PLL_MOD, CM_AUTOIDLE);
 	v &= ~OMAP24XX_AUTO_DPLL_MASK;
 	v |= m << OMAP24XX_AUTO_DPLL_SHIFT;
 	omap2_cm_write_mod_reg(v, PLL_MOD, CM_AUTOIDLE);
 }

 void omap2xxx_cm_set_dpll_disable_autoidle(void)
 {
 	_omap2xxx_set_dpll_autoidle(OMAP2XXX_DPLL_AUTOIDLE_LOW_POWER_STOP);
 }

 void omap2xxx_cm_set_dpll_auto_low_power_stop(void)
 {
 	_omap2xxx_set_dpll_autoidle(DPLL_AUTOIDLE_DISABLE);
 }

 /*
  * APLL control
  */

 static void _omap2xxx_set_apll_autoidle(u8 m, u32 mask)
 {
 	u32 v;

 	v = omap2_cm_read_mod_reg(PLL_MOD, CM_AUTOIDLE);
 	v &= ~mask;
 	v |= m << __ffs(mask);
 	omap2_cm_write_mod_reg(v, PLL_MOD, CM_AUTOIDLE);
 }

 void omap2xxx_cm_set_apll54_disable_autoidle(void)
 {
 	_omap2xxx_set_apll_autoidle(OMAP2XXX_APLL_AUTOIDLE_LOW_POWER_STOP,
 				    OMAP24XX_AUTO_54M_MASK);
 }

 void omap2xxx_cm_set_apll54_auto_low_power_stop(void)
 {
 	_omap2xxx_set_apll_autoidle(OMAP2XXX_APLL_AUTOIDLE_DISABLE,
 				    OMAP24XX_AUTO_54M_MASK);
 }

 void omap2xxx_cm_set_apll96_disable_autoidle(void)
 {
 	_omap2xxx_set_apll_autoidle(OMAP2XXX_APLL_AUTOIDLE_LOW_POWER_STOP,
 				    OMAP24XX_AUTO_96M_MASK);
 }

 void omap2xxx_cm_set_apll96_auto_low_power_stop(void)
 {
 	_omap2xxx_set_apll_autoidle(OMAP2XXX_APLL_AUTOIDLE_DISABLE,
 				    OMAP24XX_AUTO_96M_MASK);
 }

 /* Enable an APLL if off */
 static int _omap2xxx_apll_enable(u8 enable_bit, u8 status_bit)
 {
 	u32 v, m;

 	m = EN_APLL_LOCKED << enable_bit;

 	v = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKEN);
 	if (v & m)
 		return 0;   /* apll already enabled */

 	v |= m;
 	omap2_cm_write_mod_reg(v, PLL_MOD, CM_CLKEN);

 	omap2xxx_cm_wait_module_ready(0, PLL_MOD, 1, status_bit);

 	/*
 	 * REVISIT: Should we return an error code if
 	 * omap2xxx_cm_wait_module_ready() fails?
 	 */
 	return 0;
 }

 /* Stop APLL */
 static void _omap2xxx_apll_disable(u8 enable_bit)
 {
 	u32 v;

 	v = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKEN);
 	v &= ~(EN_APLL_LOCKED << enable_bit);
 	omap2_cm_write_mod_reg(v, PLL_MOD, CM_CLKEN);
 }

 /* Enable an APLL if off */
 int omap2xxx_cm_apll54_enable(void)
 {
 	return _omap2xxx_apll_enable(OMAP24XX_EN_54M_PLL_SHIFT,
 				     OMAP24XX_ST_54M_APLL_SHIFT);
 }

 /* Enable an APLL if off */
 int omap2xxx_cm_apll96_enable(void)
 {
 	return _omap2xxx_apll_enable(OMAP24XX_EN_96M_PLL_SHIFT,
 				     OMAP24XX_ST_96M_APLL_SHIFT);
 }

 /* Stop APLL */
 void omap2xxx_cm_apll54_disable(void)
 {
 	_omap2xxx_apll_disable(OMAP24XX_EN_54M_PLL_SHIFT);
 }

 /* Stop APLL */
 void omap2xxx_cm_apll96_disable(void)
 {
 	_omap2xxx_apll_disable(OMAP24XX_EN_96M_PLL_SHIFT);
 }

 /**
  * omap2xxx_cm_split_idlest_reg - split CM_IDLEST reg addr into its components
  * @idlest_reg: CM_IDLEST* virtual address
  * @prcm_inst: pointer to an s16 to return the PRCM instance offset
  * @idlest_reg_id: pointer to a u8 to return the CM_IDLESTx register ID
  *
  * XXX This function is only needed until absolute register addresses are
  * removed from the OMAP struct clk records.
  */
 static int omap2xxx_cm_split_idlest_reg(void __iomem *idlest_reg,
 					s16 *prcm_inst,
 					u8 *idlest_reg_id)
 {
 	unsigned long offs;
 	u8 idlest_offs;
 	int i;

 	if (idlest_reg < cm_base || idlest_reg > (cm_base + 0x0fff))
 		return -EINVAL;

 	idlest_offs = (unsigned long)idlest_reg & 0xff;
 	for (i = 0; i < ARRAY_SIZE(omap2xxx_cm_idlest_offs); i++) {
 		if (idlest_offs == omap2xxx_cm_idlest_offs[i]) {
 			*idlest_reg_id = i + 1;
 			break;
 		}
 	}

 	if (i == ARRAY_SIZE(omap2xxx_cm_idlest_offs))
 		return -EINVAL;

 	offs = idlest_reg - cm_base;
 	offs &= 0xff00;
 	*prcm_inst = offs;

 	return 0;
 }

 /*
  *
  */

 /**
  * omap2xxx_cm_wait_module_ready - wait for a module to leave idle or standby
  * @part: PRCM partition, ignored for OMAP2
  * @prcm_mod: PRCM module offset
  * @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
  * @idlest_shift: shift of the bit in the CM_IDLEST* register to check
  *
  * Wait for the PRCM to indicate that the module identified by
  * (@prcm_mod, @idlest_id, @idlest_shift) is clocked.  Return 0 upon
  * success or -EBUSY if the module doesn't enable in time.
  */
 int omap2xxx_cm_wait_module_ready(u8 part, s16 prcm_mod, u16 idlest_id,
 				  u8 idlest_shift)
 {
 	int ena = 0, i = 0;
 	u8 cm_idlest_reg;
 	u32 mask;

 	if (!idlest_id || (idlest_id > ARRAY_SIZE(omap2xxx_cm_idlest_offs)))
 		return -EINVAL;

 	cm_idlest_reg = omap2xxx_cm_idlest_offs[idlest_id - 1];

 	mask = 1 << idlest_shift;
 	ena = mask;

 	omap_test_timeout(((omap2_cm_read_mod_reg(prcm_mod, cm_idlest_reg) &
 			    mask) == ena), MAX_MODULE_READY_TIME, i);

 	return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
 }

 /* Clockdomain low-level functions */

 static void omap2xxx_clkdm_allow_idle(struct clockdomain *clkdm)
 {
 	omap2xxx_cm_clkdm_enable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 				       clkdm->clktrctrl_mask);
 }

 static void omap2xxx_clkdm_deny_idle(struct clockdomain *clkdm)
 {
 	omap2xxx_cm_clkdm_disable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 					clkdm->clktrctrl_mask);
 }

 static int omap2xxx_clkdm_clk_enable(struct clockdomain *clkdm)
 {
 	bool hwsup = false;

 	if (!clkdm->clktrctrl_mask)
 		return 0;

 	hwsup = omap2xxx_cm_is_clkdm_in_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 					      clkdm->clktrctrl_mask);
 	if (!hwsup && clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
 		omap2xxx_clkdm_wakeup(clkdm);

 	return 0;
 }

 static int omap2xxx_clkdm_clk_disable(struct clockdomain *clkdm)
 {
 	bool hwsup = false;

 	if (!clkdm->clktrctrl_mask)
 		return 0;

 	hwsup = omap2xxx_cm_is_clkdm_in_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 					      clkdm->clktrctrl_mask);

 	if (!hwsup && clkdm->flags & CLKDM_CAN_FORCE_SLEEP)
 		omap2xxx_clkdm_sleep(clkdm);

 	return 0;
 }

 struct clkdm_ops omap2_clkdm_operations = {
 	.clkdm_add_wkdep	= omap2_clkdm_add_wkdep,
 	.clkdm_del_wkdep	= omap2_clkdm_del_wkdep,
 	.clkdm_read_wkdep	= omap2_clkdm_read_wkdep,
 	.clkdm_clear_all_wkdeps	= omap2_clkdm_clear_all_wkdeps,
 	.clkdm_sleep		= omap2xxx_clkdm_sleep,
 	.clkdm_wakeup		= omap2xxx_clkdm_wakeup,
 	.clkdm_allow_idle	= omap2xxx_clkdm_allow_idle,
 	.clkdm_deny_idle	= omap2xxx_clkdm_deny_idle,
 	.clkdm_clk_enable	= omap2xxx_clkdm_clk_enable,
 	.clkdm_clk_disable	= omap2xxx_clkdm_clk_disable,
 };

 int omap2xxx_cm_fclks_active(void)
 {
 	u32 f1, f2;

 	f1 = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
 	f2 = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);

 	return (f1 | f2) ? 1 : 0;
 }

 int omap2xxx_cm_mpu_retention_allowed(void)
 {
 	u32 l;

 	/* Check for MMC, UART2, UART1, McSPI2, McSPI1 and DSS1. */
 	l = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
 	if (l & (OMAP2420_EN_MMC_MASK | OMAP24XX_EN_UART2_MASK |
 		 OMAP24XX_EN_UART1_MASK | OMAP24XX_EN_MCSPI2_MASK |
 		 OMAP24XX_EN_MCSPI1_MASK | OMAP24XX_EN_DSS1_MASK))
 		return 0;
 	/* Check for UART3. */
 	l = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);
 	if (l & OMAP24XX_EN_UART3_MASK)
 		return 0;

 	return 1;
 }

 u32 omap2xxx_cm_get_core_clk_src(void)
 {
 	u32 v;

 	v = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
 	v &= OMAP24XX_CORE_CLK_SRC_MASK;

 	return v;
 }

 u32 omap2xxx_cm_get_core_pll_config(void)
 {
 	return omap2_cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
 }

 void omap2xxx_cm_set_mod_dividers(u32 mpu, u32 dsp, u32 gfx, u32 core, u32 mdm)
 {
 	u32 tmp;

 	omap2_cm_write_mod_reg(mpu, MPU_MOD, CM_CLKSEL);
 	omap2_cm_write_mod_reg(dsp, OMAP24XX_DSP_MOD, CM_CLKSEL);
 	omap2_cm_write_mod_reg(gfx, GFX_MOD, CM_CLKSEL);
 	tmp = omap2_cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) &
 		OMAP24XX_CLKSEL_DSS2_MASK;
 	omap2_cm_write_mod_reg(core | tmp, CORE_MOD, CM_CLKSEL1);
 	if (mdm)
 		omap2_cm_write_mod_reg(mdm, OMAP2430_MDM_MOD, CM_CLKSEL);
 }

 /*
  *
  */

 static struct cm_ll_data omap2xxx_cm_ll_data = {
 	.split_idlest_reg	= &omap2xxx_cm_split_idlest_reg,
 	.wait_module_ready	= &omap2xxx_cm_wait_module_ready,
 };

 int __init omap2xxx_cm_init(const struct omap_prcm_init_data *data)
 {
 	return cm_register(&omap2xxx_cm_ll_data);
 }

 static void __exit omap2xxx_cm_exit(void)
 {
 	cm_unregister(&omap2xxx_cm_ll_data);
 }
 __exitcall(omap2xxx_cm_exit);
	/*
	* OMAP2xxx CM module functions
	*
	* Copyright (C) 2009 Nokia Corporation
	* Copyright (C) 2008-2010, 2012 Texas Instruments, Inc.
	* Paul Walmsley
	* Rajendra Nayak <rnayak@ti.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/types.h>
	#include <linux/delay.h>
	#include <linux/errno.h>
	#include <linux/err.h>
	#include <linux/io.h>

	#include "prm2xxx.h"
	#include "cm.h"
	#include "cm2xxx.h"
	#include "cm-regbits-24xx.h"
	#include "clockdomain.h"

	/* CM_AUTOIDLE_PLL.AUTO_* bit values for DPLLs */
	#define DPLL_AUTOIDLE_DISABLE 0x0
	#define OMAP2XXX_DPLL_AUTOIDLE_LOW_POWER_STOP 0x3

	/* CM_AUTOIDLE_PLL.AUTO_* bit values for APLLs (OMAP2xxx only) */
	#define OMAP2XXX_APLL_AUTOIDLE_DISABLE 0x0
	#define OMAP2XXX_APLL_AUTOIDLE_LOW_POWER_STOP 0x3

	/* CM_IDLEST_PLL bit value offset for APLLs (OMAP2xxx only) */
	#define EN_APLL_LOCKED 3

	static const u8 omap2xxx_cm_idlest_offs[] = {
	CM_IDLEST1, CM_IDLEST2, OMAP2430_CM_IDLEST3, OMAP24XX_CM_IDLEST4
	};

	/*
	*
	*/

	static void _write_clktrctrl(u8 c, s16 module, u32 mask)
	{
	u32 v;

	v = omap2_cm_read_mod_reg(module, OMAP2_CM_CLKSTCTRL);
	v &= ~mask;
	v \|= c << __ffs(mask);
	omap2_cm_write_mod_reg(v, module, OMAP2_CM_CLKSTCTRL);
	}

	static bool omap2xxx_cm_is_clkdm_in_hwsup(s16 module, u32 mask)
	{
	u32 v;

	v = omap2_cm_read_mod_reg(module, OMAP2_CM_CLKSTCTRL);
	v &= mask;
	v >>= __ffs(mask);

	return (v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO) ? 1 : 0;
	}

	static void omap2xxx_cm_clkdm_enable_hwsup(s16 module, u32 mask)
	{
	_write_clktrctrl(OMAP24XX_CLKSTCTRL_ENABLE_AUTO, module, mask);
	}

	static void omap2xxx_cm_clkdm_disable_hwsup(s16 module, u32 mask)
	{
	_write_clktrctrl(OMAP24XX_CLKSTCTRL_DISABLE_AUTO, module, mask);
	}

	/*
	* DPLL autoidle control
	*/

	static void _omap2xxx_set_dpll_autoidle(u8 m)
	{
	u32 v;

	v = omap2_cm_read_mod_reg(PLL_MOD, CM_AUTOIDLE);
	v &= ~OMAP24XX_AUTO_DPLL_MASK;
	v \|= m << OMAP24XX_AUTO_DPLL_SHIFT;
	omap2_cm_write_mod_reg(v, PLL_MOD, CM_AUTOIDLE);
	}

	void omap2xxx_cm_set_dpll_disable_autoidle(void)
	{
	_omap2xxx_set_dpll_autoidle(OMAP2XXX_DPLL_AUTOIDLE_LOW_POWER_STOP);
	}

	void omap2xxx_cm_set_dpll_auto_low_power_stop(void)
	{
	_omap2xxx_set_dpll_autoidle(DPLL_AUTOIDLE_DISABLE);
	}

	/*
	* APLL control
	*/

	static void _omap2xxx_set_apll_autoidle(u8 m, u32 mask)
	{
	u32 v;

	v = omap2_cm_read_mod_reg(PLL_MOD, CM_AUTOIDLE);
	v &= ~mask;
	v \|= m << __ffs(mask);
	omap2_cm_write_mod_reg(v, PLL_MOD, CM_AUTOIDLE);
	}

	void omap2xxx_cm_set_apll54_disable_autoidle(void)
	{
	_omap2xxx_set_apll_autoidle(OMAP2XXX_APLL_AUTOIDLE_LOW_POWER_STOP,
	OMAP24XX_AUTO_54M_MASK);
	}

	void omap2xxx_cm_set_apll54_auto_low_power_stop(void)
	{
	_omap2xxx_set_apll_autoidle(OMAP2XXX_APLL_AUTOIDLE_DISABLE,
	OMAP24XX_AUTO_54M_MASK);
	}

	void omap2xxx_cm_set_apll96_disable_autoidle(void)
	{
	_omap2xxx_set_apll_autoidle(OMAP2XXX_APLL_AUTOIDLE_LOW_POWER_STOP,
	OMAP24XX_AUTO_96M_MASK);
	}

	void omap2xxx_cm_set_apll96_auto_low_power_stop(void)
	{
	_omap2xxx_set_apll_autoidle(OMAP2XXX_APLL_AUTOIDLE_DISABLE,
	OMAP24XX_AUTO_96M_MASK);
	}

	/* Enable an APLL if off */
	static int _omap2xxx_apll_enable(u8 enable_bit, u8 status_bit)
	{
	u32 v, m;

	m = EN_APLL_LOCKED << enable_bit;

	v = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKEN);
	if (v & m)
	return 0; /* apll already enabled */

	v \|= m;
	omap2_cm_write_mod_reg(v, PLL_MOD, CM_CLKEN);

	omap2xxx_cm_wait_module_ready(0, PLL_MOD, 1, status_bit);

	/*
	* REVISIT: Should we return an error code if
	* omap2xxx_cm_wait_module_ready() fails?
	*/
	return 0;
	}

	/* Stop APLL */
	static void _omap2xxx_apll_disable(u8 enable_bit)
	{
	u32 v;

	v = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKEN);
	v &= ~(EN_APLL_LOCKED << enable_bit);
	omap2_cm_write_mod_reg(v, PLL_MOD, CM_CLKEN);
	}

	/* Enable an APLL if off */
	int omap2xxx_cm_apll54_enable(void)
	{
	return _omap2xxx_apll_enable(OMAP24XX_EN_54M_PLL_SHIFT,
	OMAP24XX_ST_54M_APLL_SHIFT);
	}

	/* Enable an APLL if off */
	int omap2xxx_cm_apll96_enable(void)
	{
	return _omap2xxx_apll_enable(OMAP24XX_EN_96M_PLL_SHIFT,
	OMAP24XX_ST_96M_APLL_SHIFT);
	}

	/* Stop APLL */
	void omap2xxx_cm_apll54_disable(void)
	{
	_omap2xxx_apll_disable(OMAP24XX_EN_54M_PLL_SHIFT);
	}

	/* Stop APLL */
	void omap2xxx_cm_apll96_disable(void)
	{
	_omap2xxx_apll_disable(OMAP24XX_EN_96M_PLL_SHIFT);
	}

	/**
	* omap2xxx_cm_split_idlest_reg - split CM_IDLEST reg addr into its components
	* @idlest_reg: CM_IDLEST* virtual address
	* @prcm_inst: pointer to an s16 to return the PRCM instance offset
	* @idlest_reg_id: pointer to a u8 to return the CM_IDLESTx register ID
	*
	* XXX This function is only needed until absolute register addresses are
	* removed from the OMAP struct clk records.
	*/
	static int omap2xxx_cm_split_idlest_reg(void __iomem *idlest_reg,
	s16 *prcm_inst,
	u8 *idlest_reg_id)
	{
	unsigned long offs;
	u8 idlest_offs;
	int i;

	if (idlest_reg < cm_base \|\| idlest_reg > (cm_base + 0x0fff))
	return -EINVAL;

	idlest_offs = (unsigned long)idlest_reg & 0xff;
	for (i = 0; i < ARRAY_SIZE(omap2xxx_cm_idlest_offs); i++) {
	if (idlest_offs == omap2xxx_cm_idlest_offs[i]) {
	*idlest_reg_id = i + 1;
	break;
	}
	}

	if (i == ARRAY_SIZE(omap2xxx_cm_idlest_offs))
	return -EINVAL;

	offs = idlest_reg - cm_base;
	offs &= 0xff00;
	*prcm_inst = offs;

	return 0;
	}

	/*
	*
	*/

	/**
	* omap2xxx_cm_wait_module_ready - wait for a module to leave idle or standby
	* @part: PRCM partition, ignored for OMAP2
	* @prcm_mod: PRCM module offset
	* @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
	* @idlest_shift: shift of the bit in the CM_IDLEST* register to check
	*
	* Wait for the PRCM to indicate that the module identified by
	* (@prcm_mod, @idlest_id, @idlest_shift) is clocked. Return 0 upon
	* success or -EBUSY if the module doesn't enable in time.
	*/
	int omap2xxx_cm_wait_module_ready(u8 part, s16 prcm_mod, u16 idlest_id,
	u8 idlest_shift)
	{
	int ena = 0, i = 0;
	u8 cm_idlest_reg;
	u32 mask;

	if (!idlest_id \|\| (idlest_id > ARRAY_SIZE(omap2xxx_cm_idlest_offs)))
	return -EINVAL;

	cm_idlest_reg = omap2xxx_cm_idlest_offs[idlest_id - 1];

	mask = 1 << idlest_shift;
	ena = mask;

	omap_test_timeout(((omap2_cm_read_mod_reg(prcm_mod, cm_idlest_reg) &
	mask) == ena), MAX_MODULE_READY_TIME, i);

	return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
	}

	/* Clockdomain low-level functions */

	static void omap2xxx_clkdm_allow_idle(struct clockdomain *clkdm)
	{
	omap2xxx_cm_clkdm_enable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
	clkdm->clktrctrl_mask);
	}

	static void omap2xxx_clkdm_deny_idle(struct clockdomain *clkdm)
	{
	omap2xxx_cm_clkdm_disable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
	clkdm->clktrctrl_mask);
	}

	static int omap2xxx_clkdm_clk_enable(struct clockdomain *clkdm)
	{
	bool hwsup = false;

	if (!clkdm->clktrctrl_mask)
	return 0;

	hwsup = omap2xxx_cm_is_clkdm_in_hwsup(clkdm->pwrdm.ptr->prcm_offs,
	clkdm->clktrctrl_mask);
	if (!hwsup && clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
	omap2xxx_clkdm_wakeup(clkdm);

	return 0;
	}

	static int omap2xxx_clkdm_clk_disable(struct clockdomain *clkdm)
	{
	bool hwsup = false;

	if (!clkdm->clktrctrl_mask)
	return 0;

	hwsup = omap2xxx_cm_is_clkdm_in_hwsup(clkdm->pwrdm.ptr->prcm_offs,
	clkdm->clktrctrl_mask);

	if (!hwsup && clkdm->flags & CLKDM_CAN_FORCE_SLEEP)
	omap2xxx_clkdm_sleep(clkdm);

	return 0;
	}

	struct clkdm_ops omap2_clkdm_operations = {
	.clkdm_add_wkdep = omap2_clkdm_add_wkdep,
	.clkdm_del_wkdep = omap2_clkdm_del_wkdep,
	.clkdm_read_wkdep = omap2_clkdm_read_wkdep,
	.clkdm_clear_all_wkdeps = omap2_clkdm_clear_all_wkdeps,
	.clkdm_sleep = omap2xxx_clkdm_sleep,
	.clkdm_wakeup = omap2xxx_clkdm_wakeup,
	.clkdm_allow_idle = omap2xxx_clkdm_allow_idle,
	.clkdm_deny_idle = omap2xxx_clkdm_deny_idle,
	.clkdm_clk_enable = omap2xxx_clkdm_clk_enable,
	.clkdm_clk_disable = omap2xxx_clkdm_clk_disable,
	};

	int omap2xxx_cm_fclks_active(void)
	{
	u32 f1, f2;

	f1 = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
	f2 = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);

	return (f1 \| f2) ? 1 : 0;
	}

	int omap2xxx_cm_mpu_retention_allowed(void)
	{
	u32 l;

	/* Check for MMC, UART2, UART1, McSPI2, McSPI1 and DSS1. */
	l = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
	if (l & (OMAP2420_EN_MMC_MASK \| OMAP24XX_EN_UART2_MASK \|
	OMAP24XX_EN_UART1_MASK \| OMAP24XX_EN_MCSPI2_MASK \|
	OMAP24XX_EN_MCSPI1_MASK \| OMAP24XX_EN_DSS1_MASK))
	return 0;
	/* Check for UART3. */
	l = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);
	if (l & OMAP24XX_EN_UART3_MASK)
	return 0;

	return 1;
	}

	u32 omap2xxx_cm_get_core_clk_src(void)
	{
	u32 v;

	v = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
	v &= OMAP24XX_CORE_CLK_SRC_MASK;

	return v;
	}

	u32 omap2xxx_cm_get_core_pll_config(void)
	{
	return omap2_cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
	}

	void omap2xxx_cm_set_mod_dividers(u32 mpu, u32 dsp, u32 gfx, u32 core, u32 mdm)
	{
	u32 tmp;

	omap2_cm_write_mod_reg(mpu, MPU_MOD, CM_CLKSEL);
	omap2_cm_write_mod_reg(dsp, OMAP24XX_DSP_MOD, CM_CLKSEL);
	omap2_cm_write_mod_reg(gfx, GFX_MOD, CM_CLKSEL);
	tmp = omap2_cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) &
	OMAP24XX_CLKSEL_DSS2_MASK;
	omap2_cm_write_mod_reg(core \| tmp, CORE_MOD, CM_CLKSEL1);
	if (mdm)
	omap2_cm_write_mod_reg(mdm, OMAP2430_MDM_MOD, CM_CLKSEL);
	}

	/*
	*
	*/

	static struct cm_ll_data omap2xxx_cm_ll_data = {
	.split_idlest_reg = &omap2xxx_cm_split_idlest_reg,
	.wait_module_ready = &omap2xxx_cm_wait_module_ready,
	};

	int __init omap2xxx_cm_init(const struct omap_prcm_init_data *data)
	{
	return cm_register(&omap2xxx_cm_ll_data);
	}

	static void __exit omap2xxx_cm_exit(void)
	{
	cm_unregister(&omap2xxx_cm_ll_data);
	}
	__exitcall(omap2xxx_cm_exit);