arch/arm/mach-omap2/prm33xx.c - linux - Git at Google

 /*
  * AM33XX PRM functions
  *
  * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation version 2.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  * kind, whether express or implied; without even the implied warranty
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/io.h>

 #include "powerdomain.h"
 #include "prm33xx.h"
 #include "prm-regbits-33xx.h"

 #define AM33XX_PRM_RSTCTRL_OFFSET		0x0000

 #define AM33XX_RST_GLOBAL_WARM_SW_MASK		(1 << 0)

 /* Read a register in a PRM instance */
 static u32 am33xx_prm_read_reg(s16 inst, u16 idx)
 {
 	return readl_relaxed(prm_base + inst + idx);
 }

 /* Write into a register in a PRM instance */
 static void am33xx_prm_write_reg(u32 val, s16 inst, u16 idx)
 {
 	writel_relaxed(val, prm_base + inst + idx);
 }

 /* Read-modify-write a register in PRM. Caller must lock */
 static u32 am33xx_prm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx)
 {
 	u32 v;

 	v = am33xx_prm_read_reg(inst, idx);
 	v &= ~mask;
 	v |= bits;
 	am33xx_prm_write_reg(v, inst, idx);

 	return v;
 }

 /**
  * am33xx_prm_is_hardreset_asserted - read the HW reset line state of
  * submodules contained in the hwmod module
  * @shift: register bit shift corresponding to the reset line to check
  * @part: PRM partition, ignored for AM33xx
  * @inst: CM instance register offset (*_INST macro)
  * @rstctrl_offs: RM_RSTCTRL register address offset for this module
  *
  * Returns 1 if the (sub)module hardreset line is currently asserted,
  * 0 if the (sub)module hardreset line is not currently asserted, or
  * -EINVAL upon parameter error.
  */
 static int am33xx_prm_is_hardreset_asserted(u8 shift, u8 part, s16 inst,
 					    u16 rstctrl_offs)
 {
 	u32 v;

 	v = am33xx_prm_read_reg(inst, rstctrl_offs);
 	v &= 1 << shift;
 	v >>= shift;

 	return v;
 }

 /**
  * am33xx_prm_assert_hardreset - assert the HW reset line of a submodule
  * @shift: register bit shift corresponding to the reset line to assert
  * @part: CM partition, ignored for AM33xx
  * @inst: CM instance register offset (*_INST macro)
  * @rstctrl_reg: RM_RSTCTRL register address for this module
  *
  * Some IPs like dsp, ipu or iva contain processors that require an HW
  * reset line to be asserted / deasserted in order to fully enable the
  * IP.  These modules may have multiple hard-reset lines that reset
  * different 'submodules' inside the IP block.  This function will
  * place the submodule into reset.  Returns 0 upon success or -EINVAL
  * upon an argument error.
  */
 static int am33xx_prm_assert_hardreset(u8 shift, u8 part, s16 inst,
 				       u16 rstctrl_offs)
 {
 	u32 mask = 1 << shift;

 	am33xx_prm_rmw_reg_bits(mask, mask, inst, rstctrl_offs);

 	return 0;
 }

 /**
  * am33xx_prm_deassert_hardreset - deassert a submodule hardreset line and
  * wait
  * @shift: register bit shift corresponding to the reset line to deassert
  * @st_shift: reset status register bit shift corresponding to the reset line
  * @part: PRM partition, not used for AM33xx
  * @inst: CM instance register offset (*_INST macro)
  * @rstctrl_reg: RM_RSTCTRL register address for this module
  * @rstst_reg: RM_RSTST register address for this module
  *
  * Some IPs like dsp, ipu or iva contain processors that require an HW
  * reset line to be asserted / deasserted in order to fully enable the
  * IP.  These modules may have multiple hard-reset lines that reset
  * different 'submodules' inside the IP block.  This function will
  * take the submodule out of reset and wait until the PRCM indicates
  * that the reset has completed before returning.  Returns 0 upon success or
  * -EINVAL upon an argument error, -EEXIST if the submodule was already out
  * of reset, or -EBUSY if the submodule did not exit reset promptly.
  */
 static int am33xx_prm_deassert_hardreset(u8 shift, u8 st_shift, u8 part,
 					 s16 inst, u16 rstctrl_offs,
 					 u16 rstst_offs)
 {
 	int c;
 	u32 mask = 1 << st_shift;

 	/* Check the current status to avoid  de-asserting the line twice */
 	if (am33xx_prm_is_hardreset_asserted(shift, 0, inst, rstctrl_offs) == 0)
 		return -EEXIST;

 	/* Clear the reset status by writing 1 to the status bit */
 	am33xx_prm_rmw_reg_bits(0xffffffff, mask, inst, rstst_offs);

 	/* de-assert the reset control line */
 	mask = 1 << shift;

 	am33xx_prm_rmw_reg_bits(mask, 0, inst, rstctrl_offs);

 	/* wait the status to be set */
 	omap_test_timeout(am33xx_prm_is_hardreset_asserted(st_shift, 0, inst,
 							   rstst_offs),
 			  MAX_MODULE_HARDRESET_WAIT, c);

 	return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
 }

 static int am33xx_pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
 {
 	am33xx_prm_rmw_reg_bits(OMAP_POWERSTATE_MASK,
 				(pwrst << OMAP_POWERSTATE_SHIFT),
 				pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 	return 0;
 }

 static int am33xx_pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
 {
 	u32 v;

 	v = am33xx_prm_read_reg(pwrdm->prcm_offs,  pwrdm->pwrstctrl_offs);
 	v &= OMAP_POWERSTATE_MASK;
 	v >>= OMAP_POWERSTATE_SHIFT;

 	return v;
 }

 static int am33xx_pwrdm_read_pwrst(struct powerdomain *pwrdm)
 {
 	u32 v;

 	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 	v &= OMAP_POWERSTATEST_MASK;
 	v >>= OMAP_POWERSTATEST_SHIFT;

 	return v;
 }

 static int am33xx_pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
 {
 	u32 v;

 	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 	v &= AM33XX_LASTPOWERSTATEENTERED_MASK;
 	v >>= AM33XX_LASTPOWERSTATEENTERED_SHIFT;

 	return v;
 }

 static int am33xx_pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm)
 {
 	am33xx_prm_rmw_reg_bits(AM33XX_LOWPOWERSTATECHANGE_MASK,
 				(1 << AM33XX_LOWPOWERSTATECHANGE_SHIFT),
 				pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 	return 0;
 }

 static int am33xx_pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
 {
 	am33xx_prm_rmw_reg_bits(AM33XX_LASTPOWERSTATEENTERED_MASK,
 				AM33XX_LASTPOWERSTATEENTERED_MASK,
 				pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 	return 0;
 }

 static int am33xx_pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
 {
 	u32 m;

 	m = pwrdm->logicretstate_mask;
 	if (!m)
 		return -EINVAL;

 	am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
 				pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);

 	return 0;
 }

 static int am33xx_pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
 {
 	u32 v;

 	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 	v &= AM33XX_LOGICSTATEST_MASK;
 	v >>= AM33XX_LOGICSTATEST_SHIFT;

 	return v;
 }

 static int am33xx_pwrdm_read_logic_retst(struct powerdomain *pwrdm)
 {
 	u32 v, m;

 	m = pwrdm->logicretstate_mask;
 	if (!m)
 		return -EINVAL;

 	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 	v &= m;
 	v >>= __ffs(m);

 	return v;
 }

 static int am33xx_pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank,
 		u8 pwrst)
 {
 	u32 m;

 	m = pwrdm->mem_on_mask[bank];
 	if (!m)
 		return -EINVAL;

 	am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
 				pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);

 	return 0;
 }

 static int am33xx_pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank,
 					u8 pwrst)
 {
 	u32 m;

 	m = pwrdm->mem_ret_mask[bank];
 	if (!m)
 		return -EINVAL;

 	am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
 				pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);

 	return 0;
 }

 static int am33xx_pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
 {
 	u32 m, v;

 	m = pwrdm->mem_pwrst_mask[bank];
 	if (!m)
 		return -EINVAL;

 	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 	v &= m;
 	v >>= __ffs(m);

 	return v;
 }

 static int am33xx_pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
 {
 	u32 m, v;

 	m = pwrdm->mem_retst_mask[bank];
 	if (!m)
 		return -EINVAL;

 	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 	v &= m;
 	v >>= __ffs(m);

 	return v;
 }

 static int am33xx_pwrdm_wait_transition(struct powerdomain *pwrdm)
 {
 	u32 c = 0;

 	/*
 	 * REVISIT: pwrdm_wait_transition() may be better implemented
 	 * via a callback and a periodic timer check -- how long do we expect
 	 * powerdomain transitions to take?
 	 */

 	/* XXX Is this udelay() value meaningful? */
 	while ((am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs)
 			& OMAP_INTRANSITION_MASK) &&
 			(c++ < PWRDM_TRANSITION_BAILOUT))
 		udelay(1);

 	if (c > PWRDM_TRANSITION_BAILOUT) {
 		pr_err("powerdomain: %s: waited too long to complete transition\n",
 		       pwrdm->name);
 		return -EAGAIN;
 	}

 	pr_debug("powerdomain: completed transition in %d loops\n", c);

 	return 0;
 }

 static int am33xx_check_vcvp(void)
 {
 	/* No VC/VP on am33xx devices */
 	return 0;
 }

 /**
  * am33xx_prm_global_warm_sw_reset - reboot the device via warm reset
  *
  * Immediately reboots the device through warm reset.
  */
 static void am33xx_prm_global_warm_sw_reset(void)
 {
 	am33xx_prm_rmw_reg_bits(AM33XX_RST_GLOBAL_WARM_SW_MASK,
 				AM33XX_RST_GLOBAL_WARM_SW_MASK,
 				AM33XX_PRM_DEVICE_MOD,
 				AM33XX_PRM_RSTCTRL_OFFSET);

 	/* OCP barrier */
 	(void)am33xx_prm_read_reg(AM33XX_PRM_DEVICE_MOD,
 				  AM33XX_PRM_RSTCTRL_OFFSET);
 }

 struct pwrdm_ops am33xx_pwrdm_operations = {
 	.pwrdm_set_next_pwrst		= am33xx_pwrdm_set_next_pwrst,
 	.pwrdm_read_next_pwrst		= am33xx_pwrdm_read_next_pwrst,
 	.pwrdm_read_pwrst		= am33xx_pwrdm_read_pwrst,
 	.pwrdm_read_prev_pwrst		= am33xx_pwrdm_read_prev_pwrst,
 	.pwrdm_set_logic_retst		= am33xx_pwrdm_set_logic_retst,
 	.pwrdm_read_logic_pwrst		= am33xx_pwrdm_read_logic_pwrst,
 	.pwrdm_read_logic_retst		= am33xx_pwrdm_read_logic_retst,
 	.pwrdm_clear_all_prev_pwrst	= am33xx_pwrdm_clear_all_prev_pwrst,
 	.pwrdm_set_lowpwrstchange	= am33xx_pwrdm_set_lowpwrstchange,
 	.pwrdm_read_mem_pwrst		= am33xx_pwrdm_read_mem_pwrst,
 	.pwrdm_read_mem_retst		= am33xx_pwrdm_read_mem_retst,
 	.pwrdm_set_mem_onst		= am33xx_pwrdm_set_mem_onst,
 	.pwrdm_set_mem_retst		= am33xx_pwrdm_set_mem_retst,
 	.pwrdm_wait_transition		= am33xx_pwrdm_wait_transition,
 	.pwrdm_has_voltdm		= am33xx_check_vcvp,
 };

 static struct prm_ll_data am33xx_prm_ll_data = {
 	.assert_hardreset		= am33xx_prm_assert_hardreset,
 	.deassert_hardreset		= am33xx_prm_deassert_hardreset,
 	.is_hardreset_asserted		= am33xx_prm_is_hardreset_asserted,
 	.reset_system			= am33xx_prm_global_warm_sw_reset,
 };

 int __init am33xx_prm_init(void)
 {
 	return prm_register(&am33xx_prm_ll_data);
 }

 static void __exit am33xx_prm_exit(void)
 {
 	prm_unregister(&am33xx_prm_ll_data);
 }
 __exitcall(am33xx_prm_exit);
	/*
	* AM33XX PRM functions
	*
	* Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation version 2.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	* kind, whether express or implied; without even the implied warranty
	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/errno.h>
	#include <linux/err.h>
	#include <linux/io.h>

	#include "powerdomain.h"
	#include "prm33xx.h"
	#include "prm-regbits-33xx.h"

	#define AM33XX_PRM_RSTCTRL_OFFSET 0x0000

	#define AM33XX_RST_GLOBAL_WARM_SW_MASK (1 << 0)

	/* Read a register in a PRM instance */
	static u32 am33xx_prm_read_reg(s16 inst, u16 idx)
	{
	return readl_relaxed(prm_base + inst + idx);
	}

	/* Write into a register in a PRM instance */
	static void am33xx_prm_write_reg(u32 val, s16 inst, u16 idx)
	{
	writel_relaxed(val, prm_base + inst + idx);
	}

	/* Read-modify-write a register in PRM. Caller must lock */
	static u32 am33xx_prm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx)
	{
	u32 v;

	v = am33xx_prm_read_reg(inst, idx);
	v &= ~mask;
	v \|= bits;
	am33xx_prm_write_reg(v, inst, idx);

	return v;
	}

	/**
	* am33xx_prm_is_hardreset_asserted - read the HW reset line state of
	* submodules contained in the hwmod module
	* @shift: register bit shift corresponding to the reset line to check
	* @part: PRM partition, ignored for AM33xx
	* @inst: CM instance register offset (*_INST macro)
	* @rstctrl_offs: RM_RSTCTRL register address offset for this module
	*
	* Returns 1 if the (sub)module hardreset line is currently asserted,
	* 0 if the (sub)module hardreset line is not currently asserted, or
	* -EINVAL upon parameter error.
	*/
	static int am33xx_prm_is_hardreset_asserted(u8 shift, u8 part, s16 inst,
	u16 rstctrl_offs)
	{
	u32 v;

	v = am33xx_prm_read_reg(inst, rstctrl_offs);
	v &= 1 << shift;
	v >>= shift;

	return v;
	}

	/**
	* am33xx_prm_assert_hardreset - assert the HW reset line of a submodule
	* @shift: register bit shift corresponding to the reset line to assert
	* @part: CM partition, ignored for AM33xx
	* @inst: CM instance register offset (*_INST macro)
	* @rstctrl_reg: RM_RSTCTRL register address for this module
	*
	* Some IPs like dsp, ipu or iva contain processors that require an HW
	* reset line to be asserted / deasserted in order to fully enable the
	* IP. These modules may have multiple hard-reset lines that reset
	* different 'submodules' inside the IP block. This function will
	* place the submodule into reset. Returns 0 upon success or -EINVAL
	* upon an argument error.
	*/
	static int am33xx_prm_assert_hardreset(u8 shift, u8 part, s16 inst,
	u16 rstctrl_offs)
	{
	u32 mask = 1 << shift;

	am33xx_prm_rmw_reg_bits(mask, mask, inst, rstctrl_offs);

	return 0;
	}

	/**
	* am33xx_prm_deassert_hardreset - deassert a submodule hardreset line and
	* wait
	* @shift: register bit shift corresponding to the reset line to deassert
	* @st_shift: reset status register bit shift corresponding to the reset line
	* @part: PRM partition, not used for AM33xx
	* @inst: CM instance register offset (*_INST macro)
	* @rstctrl_reg: RM_RSTCTRL register address for this module
	* @rstst_reg: RM_RSTST register address for this module
	*
	* Some IPs like dsp, ipu or iva contain processors that require an HW
	* reset line to be asserted / deasserted in order to fully enable the
	* IP. These modules may have multiple hard-reset lines that reset
	* different 'submodules' inside the IP block. This function will
	* take the submodule out of reset and wait until the PRCM indicates
	* that the reset has completed before returning. Returns 0 upon success or
	* -EINVAL upon an argument error, -EEXIST if the submodule was already out
	* of reset, or -EBUSY if the submodule did not exit reset promptly.
	*/
	static int am33xx_prm_deassert_hardreset(u8 shift, u8 st_shift, u8 part,
	s16 inst, u16 rstctrl_offs,
	u16 rstst_offs)
	{
	int c;
	u32 mask = 1 << st_shift;

	/* Check the current status to avoid de-asserting the line twice */
	if (am33xx_prm_is_hardreset_asserted(shift, 0, inst, rstctrl_offs) == 0)
	return -EEXIST;

	/* Clear the reset status by writing 1 to the status bit */
	am33xx_prm_rmw_reg_bits(0xffffffff, mask, inst, rstst_offs);

	/* de-assert the reset control line */
	mask = 1 << shift;

	am33xx_prm_rmw_reg_bits(mask, 0, inst, rstctrl_offs);

	/* wait the status to be set */
	omap_test_timeout(am33xx_prm_is_hardreset_asserted(st_shift, 0, inst,
	rstst_offs),
	MAX_MODULE_HARDRESET_WAIT, c);

	return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
	}

	static int am33xx_pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
	{
	am33xx_prm_rmw_reg_bits(OMAP_POWERSTATE_MASK,
	(pwrst << OMAP_POWERSTATE_SHIFT),
	pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
	return 0;
	}

	static int am33xx_pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
	{
	u32 v;

	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
	v &= OMAP_POWERSTATE_MASK;
	v >>= OMAP_POWERSTATE_SHIFT;

	return v;
	}

	static int am33xx_pwrdm_read_pwrst(struct powerdomain *pwrdm)
	{
	u32 v;

	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
	v &= OMAP_POWERSTATEST_MASK;
	v >>= OMAP_POWERSTATEST_SHIFT;

	return v;
	}

	static int am33xx_pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
	{
	u32 v;

	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
	v &= AM33XX_LASTPOWERSTATEENTERED_MASK;
	v >>= AM33XX_LASTPOWERSTATEENTERED_SHIFT;

	return v;
	}

	static int am33xx_pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm)
	{
	am33xx_prm_rmw_reg_bits(AM33XX_LOWPOWERSTATECHANGE_MASK,
	(1 << AM33XX_LOWPOWERSTATECHANGE_SHIFT),
	pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
	return 0;
	}

	static int am33xx_pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
	{
	am33xx_prm_rmw_reg_bits(AM33XX_LASTPOWERSTATEENTERED_MASK,
	AM33XX_LASTPOWERSTATEENTERED_MASK,
	pwrdm->prcm_offs, pwrdm->pwrstst_offs);
	return 0;
	}

	static int am33xx_pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
	{
	u32 m;

	m = pwrdm->logicretstate_mask;
	if (!m)
	return -EINVAL;

	am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
	pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);

	return 0;
	}

	static int am33xx_pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
	{
	u32 v;

	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
	v &= AM33XX_LOGICSTATEST_MASK;
	v >>= AM33XX_LOGICSTATEST_SHIFT;

	return v;
	}

	static int am33xx_pwrdm_read_logic_retst(struct powerdomain *pwrdm)
	{
	u32 v, m;

	m = pwrdm->logicretstate_mask;
	if (!m)
	return -EINVAL;

	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
	v &= m;
	v >>= __ffs(m);

	return v;
	}

	static int am33xx_pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank,
	u8 pwrst)
	{
	u32 m;

	m = pwrdm->mem_on_mask[bank];
	if (!m)
	return -EINVAL;

	am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
	pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);

	return 0;
	}

	static int am33xx_pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank,
	u8 pwrst)
	{
	u32 m;

	m = pwrdm->mem_ret_mask[bank];
	if (!m)
	return -EINVAL;

	am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
	pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);

	return 0;
	}

	static int am33xx_pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
	{
	u32 m, v;

	m = pwrdm->mem_pwrst_mask[bank];
	if (!m)
	return -EINVAL;

	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
	v &= m;
	v >>= __ffs(m);

	return v;
	}

	static int am33xx_pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
	{
	u32 m, v;

	m = pwrdm->mem_retst_mask[bank];
	if (!m)
	return -EINVAL;

	v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
	v &= m;
	v >>= __ffs(m);

	return v;
	}

	static int am33xx_pwrdm_wait_transition(struct powerdomain *pwrdm)
	{
	u32 c = 0;

	/*
	* REVISIT: pwrdm_wait_transition() may be better implemented
	* via a callback and a periodic timer check -- how long do we expect
	* powerdomain transitions to take?
	*/

	/* XXX Is this udelay() value meaningful? */
	while ((am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs)
	& OMAP_INTRANSITION_MASK) &&
	(c++ < PWRDM_TRANSITION_BAILOUT))
	udelay(1);

	if (c > PWRDM_TRANSITION_BAILOUT) {
	pr_err("powerdomain: %s: waited too long to complete transition\n",
	pwrdm->name);
	return -EAGAIN;
	}

	pr_debug("powerdomain: completed transition in %d loops\n", c);

	return 0;
	}

	static int am33xx_check_vcvp(void)
	{
	/* No VC/VP on am33xx devices */
	return 0;
	}

	/**
	* am33xx_prm_global_warm_sw_reset - reboot the device via warm reset
	*
	* Immediately reboots the device through warm reset.
	*/
	static void am33xx_prm_global_warm_sw_reset(void)
	{
	am33xx_prm_rmw_reg_bits(AM33XX_RST_GLOBAL_WARM_SW_MASK,
	AM33XX_RST_GLOBAL_WARM_SW_MASK,
	AM33XX_PRM_DEVICE_MOD,
	AM33XX_PRM_RSTCTRL_OFFSET);

	/* OCP barrier */
	(void)am33xx_prm_read_reg(AM33XX_PRM_DEVICE_MOD,
	AM33XX_PRM_RSTCTRL_OFFSET);
	}

	struct pwrdm_ops am33xx_pwrdm_operations = {
	.pwrdm_set_next_pwrst = am33xx_pwrdm_set_next_pwrst,
	.pwrdm_read_next_pwrst = am33xx_pwrdm_read_next_pwrst,
	.pwrdm_read_pwrst = am33xx_pwrdm_read_pwrst,
	.pwrdm_read_prev_pwrst = am33xx_pwrdm_read_prev_pwrst,
	.pwrdm_set_logic_retst = am33xx_pwrdm_set_logic_retst,
	.pwrdm_read_logic_pwrst = am33xx_pwrdm_read_logic_pwrst,
	.pwrdm_read_logic_retst = am33xx_pwrdm_read_logic_retst,
	.pwrdm_clear_all_prev_pwrst = am33xx_pwrdm_clear_all_prev_pwrst,
	.pwrdm_set_lowpwrstchange = am33xx_pwrdm_set_lowpwrstchange,
	.pwrdm_read_mem_pwrst = am33xx_pwrdm_read_mem_pwrst,
	.pwrdm_read_mem_retst = am33xx_pwrdm_read_mem_retst,
	.pwrdm_set_mem_onst = am33xx_pwrdm_set_mem_onst,
	.pwrdm_set_mem_retst = am33xx_pwrdm_set_mem_retst,
	.pwrdm_wait_transition = am33xx_pwrdm_wait_transition,
	.pwrdm_has_voltdm = am33xx_check_vcvp,
	};

	static struct prm_ll_data am33xx_prm_ll_data = {
	.assert_hardreset = am33xx_prm_assert_hardreset,
	.deassert_hardreset = am33xx_prm_deassert_hardreset,
	.is_hardreset_asserted = am33xx_prm_is_hardreset_asserted,
	.reset_system = am33xx_prm_global_warm_sw_reset,
	};

	int __init am33xx_prm_init(void)
	{
	return prm_register(&am33xx_prm_ll_data);
	}

	static void __exit am33xx_prm_exit(void)
	{
	prm_unregister(&am33xx_prm_ll_data);
	}
	__exitcall(am33xx_prm_exit);