Re: [PATCH 2/5] Powerdomains: add base OMAP2/3 powerdomain code

[Tony Lindgren <tony@atomide.com>]

* Paul Walmsley <paul@pwsan.com> [080410 10:16]:
> This patch adds an interface to the powerdomain registers in the
> PRM/CM modules on OMAP2/3.  This interface is intended to be used by 
> PM code, e.g., pm.c; not by device drivers directly.
> 
> Each powerdomain will be defined in later patches as static
> structures.  Also definable are dependencies between powerdomains,
> used for adding and removing PM_WKDEP and CM_SLEEPDEP bits.  The
> powerdomain structures are linked into a list at boot by
> pwrdm_register(), similar to the OMAP clock code.
> 
> The patch adds a Kconfig option, CONFIG_OMAP_DEBUG_POWERDOMAIN, which 
> when enabled will emit verbose debug messages via pr_debug().
> 
> Signed-off-by: Paul Walmsley <paul@pwsan.com>
> 
> ---
>  arch/arm/mach-omap2/Makefile            |    2 
>  arch/arm/mach-omap2/io.c                |    3 
>  arch/arm/mach-omap2/powerdomain.c       |  884 ++++++++++++++++++++++++++++++++
>  arch/arm/plat-omap/Kconfig              |   12 
>  include/asm-arm/arch-omap/powerdomain.h |  137 ++++
>  5 files changed, 1037 insertions(+), 1 deletion(-)
> 
> Index: linux-omap/arch/arm/mach-omap2/Makefile
> ===================================================================
> --- linux-omap.orig/arch/arm/mach-omap2/Makefile	2008-04-10 08:00:56.000000000 -0600
> +++ linux-omap/arch/arm/mach-omap2/Makefile	2008-04-10 08:00:58.000000000 -0600
> @@ -4,7 +4,7 @@
>  
>  # Common support
>  obj-y := irq.o id.o io.o memory.o control.o prcm.o clock.o mux.o \
> -		devices.o serial.o gpmc.o timer-gp.o
> +		devices.o serial.o gpmc.o timer-gp.o powerdomain.o
>  
>  # Functions loaded to SRAM
>  obj-$(CONFIG_ARCH_OMAP2)		+= sram24xx.o
> Index: linux-omap/arch/arm/mach-omap2/io.c
> ===================================================================
> --- linux-omap.orig/arch/arm/mach-omap2/io.c	2008-04-10 08:00:56.000000000 -0600
> +++ linux-omap/arch/arm/mach-omap2/io.c	2008-04-10 08:00:58.000000000 -0600
> @@ -27,6 +27,8 @@
>  #include <asm/arch/mux.h>
>  #include <asm/arch/omapfb.h>
>  
> +#include <asm/arch/powerdomain.h>
> +
>  extern void omap_sram_init(void);
>  extern int omap2_clk_init(void);
>  extern void omap2_check_revision(void);
> @@ -188,6 +190,7 @@
>  void __init omap2_init_common_hw(void)
>  {
>  	omap2_mux_init();
> +	pwrdm_init(NULL);
>  	omap2_clk_init();
>  	omap2_init_memory();
>  	gpmc_init();

The pwrdm_init() above does not do anything, is the plan to make it do
something later on?


> Index: linux-omap/arch/arm/mach-omap2/powerdomain.c
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-omap/arch/arm/mach-omap2/powerdomain.c	2008-04-10 08:01:08.000000000 -0600
> @@ -0,0 +1,884 @@
> +/*
> + * OMAP powerdomain control
> + *
> + * Copyright (C) 2007-2008 Texas Instruments, Inc.
> + * Copyright (C) 2007-2008 Nokia Corporation
> + *
> + * Written by Paul Walmsley
> + *
> + * 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.
> + */
> +#ifdef CONFIG_OMAP_DEBUG_POWERDOMAIN
> +# define DEBUG
> +#endif
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/types.h>
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/list.h>
> +#include <linux/errno.h>
> +#include <linux/err.h>
> +
> +#include <asm/atomic.h>
> +
> +#include "cm.h"
> +#include "cm-regbits-34xx.h"
> +#include "prm.h"
> +#include "prm-regbits-34xx.h"
> +
> +#include <asm/arch/cpu.h>
> +#include <asm/arch/powerdomain.h>
> +
> +/* pwrdm_list contains all registered struct powerdomains */
> +static LIST_HEAD(pwrdm_list);
> +
> +/* pwrdm_mutex protects pwrdm_list add and del ops */
> +static DEFINE_MUTEX(pwrdm_mutex);
> +
> +/* Private functions */
> +
> +static u32 __attribute__((unused)) prm_read_mod_bits_shift(s16 domain, s16 idx, u32 mask)
> +{
> +	u32 v;
> +
> +	v = prm_read_mod_reg(domain, idx);
> +	v &= mask;
> +	v >>= __ffs(mask);
> +
> +	return v;
> +}
> +
> +/* _pwrdm_deps_lookup - look up the specified powerdomain in a pwrdm list */
> +static struct powerdomain *_pwrdm_deps_lookup(struct powerdomain *pwrdm,
> +					      const struct pwrdm_dep *deps)
> +{
> +	const struct pwrdm_dep *pd;
> +
> +	if (!pwrdm || !deps || !omap_chip_is(pwrdm->omap_chip))
> +		return ERR_PTR(-EINVAL);
> +
> +	for (pd = deps; pd; pd++)
> +		if (pd->pwrdm == pwrdm && omap_chip_is(pd->omap_chip))
> +			break;
> +
> +	if (!pd)
> +		return ERR_PTR(-ENOENT);
> +
> +	return pd->pwrdm;
> +}
> +
> +
> +/* Public functions */
> +
> +/**
> + * pwrdm_init - set up the powerdomain layer
> + *
> + *  * Loop through the list of powerdomains, registering all that are
> + * available on the current CPU. If pwrdm_list is supplied and not
> + * null, all of the referenced powerdomains will be registered.	 No
> + * return value.
> + */

There seems to be a tab befoe No above.


> +void pwrdm_init(struct powerdomain **pwrdm_list)
> +{
> +	struct powerdomain **p = NULL;
> +
> +	if (pwrdm_list)
> +		for (p = pwrdm_list; *p; p++)
> +			pwrdm_register(*p);
> +}
> +
> +
> +/**
> + * pwrdm_register - register a powerdomain
> + * @pwrdm: struct powerdomain * to register
> + *
> + * Adds a powerdomain to the internal powerdomain list.	 Returns
> + * -EINVAL if given a null pointer, -EEXIST if a powerdomain is
> + * already registered by the provided name, or 0 upon success.
> + */
> +int pwrdm_register(struct powerdomain *pwrdm)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	if (!omap_chip_is(pwrdm->omap_chip))
> +		return -EINVAL;
> +
> +	/* Verify that the powerdomain is not already registered */
> +	if (pwrdm_lookup(pwrdm->name))
> +		return -EEXIST;
> +
> +	mutex_lock(&pwrdm_mutex);
> +	list_add(&pwrdm->node, &pwrdm_list);
> +	mutex_unlock(&pwrdm_mutex);
> +
> +	pr_debug("powerdomain: registered %s\n", pwrdm->name);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_register);

Maybe you should have unlocked _pwrdm_lookup() and mutex_locked()
pwrdm_lookup() that calls _pwrdm_lookup(). Then mutex_lock() the
lookup and addition of new chip in pwrdm_register()?

Otherwise there's a slight chance that powerdomain gets added
between pwrdm_lookup() and list_add().


> +
> +/**
> + * pwrdm_unregister - unregister a powerdomain
> + * @pwrdm: struct powerdomain * to unregister
> + *
> + * Removes a powerdomain from the internal powerdomain list.  Returns
> + * -EINVAL if pwrdm argument is NULL.
> + */
> +int pwrdm_unregister(struct powerdomain *pwrdm)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	mutex_lock(&pwrdm_mutex);
> +	list_del(&pwrdm->node);
> +	mutex_unlock(&pwrdm_mutex);
> +
> +	pr_debug("powerdomain: unregistered %s\n", pwrdm->name);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_unregister);
> +
> +/**
> + * pwrdm_lookup - look up a powerdomain by name, return a pointer
> + * @name: name of powerdomain
> + *
> + * Find a registered powerdomain by its name.  Returns a pointer to the
> + * struct powerdomain if found, or NULL otherwise.
> + */
> +struct powerdomain *pwrdm_lookup(const char *name)
> +{
> +	struct powerdomain *pwrdm, *temp_pwrdm;
> +
> +	if (!name)
> +		return NULL;
> +
> +	pwrdm = NULL;
> +
> +	mutex_lock(&pwrdm_mutex);
> +	list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
> +		if (!strcmp(name, temp_pwrdm->name)) {
> +			pwrdm = temp_pwrdm;
> +			break;
> +		}
> +	}
> +	mutex_unlock(&pwrdm_mutex);
> +
> +	return pwrdm;
> +}
> +EXPORT_SYMBOL(pwrdm_lookup);
> +
> +/**
> + * pwrdm_for_each - call function on each registered clockdomain
> + * @fn: callback function *
> + *
> + * Call the supplied function for each registered powerdomain.
> + * The callback function can return anything but 0 to bail
> + * out early from the iterator.	 The callback function is called with
> + * the pwrdm_mutex held, so no powerdomain structure manipulation
> + * functions should be called from the callback, although hardware
> + * powerdomain control functions are fine.  Returns the last return
> + * value of the callback function, which should be 0 for success or
> + * anything else to indicate failure; or -EINVAL if the function pointer
> + * is null.
> + */
> +int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm))
> +{
> +	struct powerdomain *temp_pwrdm;
> +	int ret = 0;
> +
> +	if (!fn)
> +		return -EINVAL;
> +
> +	mutex_lock(&pwrdm_mutex);
> +	list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
> +		ret = (*fn)(temp_pwrdm);
> +		if (ret)
> +			break;
> +	}
> +	mutex_unlock(&pwrdm_mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(pwrdm_for_each);
> +
> +/**
> + * pwrdm_add_wkdep - add a wakeup dependency from pwrdm2 to pwrdm1
> + * @pwrdm1: wake this struct powerdomain * up (dependent)
> + * @pwrdm2: when this struct powerdomain * wakes up (source)
> + *
> + * When the powerdomain represented by pwrdm2 wakes up (due to an
> + * interrupt), wake up pwrdm1.	Implemented in hardware on the OMAP,
> + * this feature is designed to reduce wakeup latency of the dependent
> + * powerdomain.	 Returns -EINVAL if presented with invalid powerdomain
> + * pointers, -ENOENT if pwrdm2 cannot wake up pwrdm1 in hardware, or
> + * 0 upon success.
> + */
> +int pwrdm_add_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
> +{
> +	struct powerdomain *p;
> +
> +	if (!pwrdm1)
> +		return -EINVAL;
> +
> +	p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->wkdep_srcs);
> +	if (IS_ERR(p)) {
> +		pr_debug("powerdomain: hardware cannot set/clear wake up of "
> +			 "%s when %s wakes up\n", pwrdm1->name, pwrdm2->name);
> +		return IS_ERR(p);
> +	}
> +
> +	pr_debug("powerdomain: hardware will wake up %s when %s wakes up\n",
> +		 pwrdm1->name, pwrdm2->name);
> +
> +	prm_set_mod_reg_bits((1 << pwrdm2->dep_bit),
> +			     pwrdm1->prcm_offs, PM_WKDEP);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_add_wkdep);
> +
> +/**
> + * pwrdm_del_wkdep - remove a wakeup dependency from pwrdm2 to pwrdm1
> + * @pwrdm1: wake this struct powerdomain * up (dependent)
> + * @pwrdm2: when this struct powerdomain * wakes up (source)
> + *
> + * Remove a wakeup dependency that causes pwrdm1 to wake up when pwrdm2
> + * wakes up.  Returns -EINVAL if presented with invalid powerdomain
> + * pointers, -ENOENT if pwrdm2 cannot wake up pwrdm1 in hardware, or
> + * 0 upon success.
> + */
> +int pwrdm_del_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
> +{
> +	struct powerdomain *p;
> +
> +	if (!pwrdm1)
> +		return -EINVAL;
> +
> +	p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->wkdep_srcs);
> +	if (IS_ERR(p)) {
> +		pr_debug("powerdomain: hardware cannot set/clear wake up of "
> +			 "%s when %s wakes up\n", pwrdm1->name, pwrdm2->name);
> +		return IS_ERR(p);
> +	}
> +
> +	pr_debug("powerdomain: hardware will no longer wake up %s after %s "
> +		 "wakes up\n", pwrdm1->name, pwrdm2->name);
> +
> +	prm_clear_mod_reg_bits((1 << pwrdm2->dep_bit),
> +			       pwrdm1->prcm_offs, PM_WKDEP);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_del_wkdep);
> +
> +/**
> + * pwrdm_read_wkdep - read wakeup dependency state from pwrdm2 to pwrdm1
> + * @pwrdm1: wake this struct powerdomain * up (dependent)
> + * @pwrdm2: when this struct powerdomain * wakes up (source)
> + *
> + * Return 1 if a hardware wakeup dependency exists wherein pwrdm1 will be
> + * awoken when pwrdm2 wakes up; 0 if dependency is not set; -EINVAL
> + * if either powerdomain pointer is invalid; or -ENOENT if the hardware
> + * is incapable.
> + *
> + * REVISIT: Currently this function only represents software-controllable
> + * wakeup dependencies.	 Wakeup dependencies fixed in hardware are not
> + * yet handled here.
> + */
> +int pwrdm_read_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
> +{
> +	struct powerdomain *p;
> +
> +	if (!pwrdm1)
> +		return -EINVAL;
> +
> +	p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->wkdep_srcs);
> +	if (IS_ERR(p)) {
> +		pr_debug("powerdomain: hardware cannot set/clear wake up of "
> +			 "%s when %s wakes up\n", pwrdm1->name, pwrdm2->name);
> +		return IS_ERR(p);
> +	}
> +
> +	return prm_read_mod_bits_shift(pwrdm1->prcm_offs, PM_WKDEP,
> +					(1 << pwrdm2->dep_bit));
> +}
> +EXPORT_SYMBOL(pwrdm_read_wkdep);
> +
> +/**
> + * pwrdm_add_sleepdep - add a sleep dependency from pwrdm2 to pwrdm1
> + * @pwrdm1: prevent this struct powerdomain * from sleeping (dependent)
> + * @pwrdm2: when this struct powerdomain * is active (source)
> + *
> + * Prevent pwrdm1 from automatically going inactive (and then to
> + * retention or off) if pwrdm2 is still active.	 Returns -EINVAL if
> + * presented with invalid powerdomain pointers or called on a machine
> + * that does not support software-configurable hardware sleep dependencies,
> + * -ENOENT if the specified dependency cannot be set in hardware, or
> + * 0 upon success.
> + */
> +int pwrdm_add_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
> +{
> +	struct powerdomain *p;
> +
> +	if (!pwrdm1)
> +		return -EINVAL;
> +
> +	if (!cpu_is_omap34xx())
> +		return -EINVAL;
> +
> +	p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->sleepdep_srcs);
> +	if (IS_ERR(p)) {
> +		pr_debug("powerdomain: hardware cannot set/clear sleep "
> +			 "dependency affecting %s from %s\n", pwrdm1->name,
> +			 pwrdm2->name);
> +		return IS_ERR(p);
> +	}
> +
> +	pr_debug("powerdomain: will prevent %s from sleeping if %s is active\n",
> +		 pwrdm1->name, pwrdm2->name);
> +
> +	cm_set_mod_reg_bits((1 << pwrdm2->dep_bit),
> +			    pwrdm1->prcm_offs, OMAP3430_CM_SLEEPDEP);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_add_sleepdep);
> +
> +/**
> + * pwrdm_del_sleepdep - remove a sleep dependency from pwrdm2 to pwrdm1
> + * @pwrdm1: prevent this struct powerdomain * from sleeping (dependent)
> + * @pwrdm2: when this struct powerdomain * is active (source)
> + *
> + * Allow pwrdm1 to automatically go inactive (and then to retention or
> + * off), independent of the activity state of pwrdm2.  Returns -EINVAL
> + * if presented with invalid powerdomain pointers or called on a machine
> + * that does not support software-configurable hardware sleep dependencies,
> + * -ENOENT if the specified dependency cannot be cleared in hardware, or
> + * 0 upon success.
> + */
> +int pwrdm_del_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
> +{
> +	struct powerdomain *p;
> +
> +	if (!pwrdm1)
> +		return -EINVAL;
> +
> +	if (!cpu_is_omap34xx())
> +		return -EINVAL;
> +
> +	p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->sleepdep_srcs);
> +	if (IS_ERR(p)) {
> +		pr_debug("powerdomain: hardware cannot set/clear sleep "
> +			 "dependency affecting %s from %s\n", pwrdm1->name,
> +			 pwrdm2->name);
> +		return IS_ERR(p);
> +	}
> +
> +	pr_debug("powerdomain: will no longer prevent %s from sleeping if "
> +		 "%s is active\n", pwrdm1->name, pwrdm2->name);
> +
> +	cm_clear_mod_reg_bits((1 << pwrdm2->dep_bit),
> +			      pwrdm1->prcm_offs, OMAP3430_CM_SLEEPDEP);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_del_sleepdep);
> +
> +/**
> + * pwrdm_read_sleepdep - read sleep dependency state from pwrdm2 to pwrdm1
> + * @pwrdm1: prevent this struct powerdomain * from sleeping (dependent)
> + * @pwrdm2: when this struct powerdomain * is active (source)
> + *
> + * Return 1 if a hardware sleep dependency exists wherein pwrdm1 will
> + * not be allowed to automatically go inactive if pwrdm2 is active;
> + * 0 if pwrdm1's automatic power state inactivity transition is independent
> + * of pwrdm2's; -EINVAL if either powerdomain pointer is invalid or called
> + * on a machine that does not support software-configurable hardware sleep
> + * dependencies; or -ENOENT if the hardware is incapable.
> + *
> + * REVISIT: Currently this function only represents software-controllable
> + * sleep dependencies.	Sleep dependencies fixed in hardware are not
> + * yet handled here.
> + */
> +int pwrdm_read_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
> +{
> +	struct powerdomain *p;
> +
> +	if (!pwrdm1)
> +		return -EINVAL;
> +
> +	if (!cpu_is_omap34xx())
> +		return -EINVAL;
> +
> +	p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->sleepdep_srcs);
> +	if (IS_ERR(p)) {
> +		pr_debug("powerdomain: hardware cannot set/clear sleep "
> +			 "dependency affecting %s from %s\n", pwrdm1->name,
> +			 pwrdm2->name);
> +		return IS_ERR(p);
> +	}
> +
> +	return prm_read_mod_bits_shift(pwrdm1->prcm_offs, OMAP3430_CM_SLEEPDEP,
> +					(1 << pwrdm2->dep_bit));
> +}
> +EXPORT_SYMBOL(pwrdm_read_sleepdep);
> +
> +
> +/**
> + * pwrdm_set_next_pwrst - set next powerdomain power state
> + * @pwrdm: struct powerdomain * to set
> + * @pwrst: one of the PWRDM_POWER_* macros
> + *
> + * Set the powerdomain pwrdm's next power state to pwrst.  The powerdomain
> + * may not enter this state immediately if the preconditions for this state
> + * have not been satisfied.  Returns -EINVAL if the powerdomain pointer is
> + * null or if the power state is invalid for the powerdomin, or returns 0
> + * upon success.
> + */
> +int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	if (!(pwrdm->pwrsts & (1 << pwrst)))
> +		return -EINVAL;
> +
> +	pr_debug("powerdomain: setting next powerstate for %s to %0x\n",
> +		 pwrdm->name, pwrst);
> +
> +	prm_rmw_mod_reg_bits(OMAP_POWERSTATE_MASK,
> +			     (pwrst << OMAP_POWERSTATE_SHIFT),
> +			     pwrdm->prcm_offs, PM_PWSTCTRL);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_set_next_pwrst);
> +
> +/**
> + * pwrdm_read_next_pwrst - get next powerdomain power state
> + * @pwrdm: struct powerdomain * to get power state
> + *
> + * Return the powerdomain pwrdm's next power state.  Returns -EINVAL
> + * if the powerdomain pointer is null or returns the next power state
> + * upon success.
> + */
> +int pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	return prm_read_mod_bits_shift(pwrdm->prcm_offs, PM_PWSTCTRL,
> +					OMAP_POWERSTATE_MASK);
> +}
> +EXPORT_SYMBOL(pwrdm_read_next_pwrst);
> +
> +/**
> + * pwrdm_read_pwrst - get current powerdomain power state
> + * @pwrdm: struct powerdomain * to get power state
> + *
> + * Return the powerdomain pwrdm's current power state.	Returns -EINVAL
> + * if the powerdomain pointer is null or returns the current power state
> + * upon success.
> + */
> +int pwrdm_read_pwrst(struct powerdomain *pwrdm)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	return prm_read_mod_bits_shift(pwrdm->prcm_offs, PM_PWSTST,
> +					OMAP_POWERSTATEST_MASK);
> +}
> +EXPORT_SYMBOL(pwrdm_read_pwrst);
> +
> +/**
> + * pwrdm_read_prev_pwrst - get previous powerdomain power state
> + * @pwrdm: struct powerdomain * to get previous power state
> + *
> + * Return the powerdomain pwrdm's previous power state.	 Returns -EINVAL
> + * if the powerdomain pointer is null or returns the previous power state
> + * upon success.
> + */
> +int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	return prm_read_mod_bits_shift(pwrdm->prcm_offs, OMAP3430_PM_PREPWSTST,
> +					OMAP3430_LASTPOWERSTATEENTERED_MASK);
> +}
> +EXPORT_SYMBOL(pwrdm_read_prev_pwrst);
> +
> +/**
> + * pwrdm_set_logic_retst - set powerdomain logic power state upon retention
> + * @pwrdm: struct powerdomain * to set
> + * @pwrst: one of the PWRDM_POWER_* macros
> + *
> + * Set the next power state that the logic portion of the powerdomain
> + * pwrdm will enter when the powerdomain enters retention.  This will
> + * be either RETENTION or OFF, if supported.  Returns -EINVAL if the
> + * powerdomain pointer is null or the target power state is not not
> + * supported, or returns 0 upon success.
> + */
> +int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	if (!(pwrdm->pwrsts_logic_ret & (1 << pwrst)))
> +		return -EINVAL;
> +
> +	pr_debug("powerdomain: setting next logic powerstate for %s to %0x\n",
> +		 pwrdm->name, pwrst);
> +
> +	/*
> +	 * The register bit names below may not correspond to the
> +	 * actual names of the bits in each powerdomain's register,
> +	 * but the type of value returned is the same for each
> +	 * powerdomain.
> +	 */
> +	prm_rmw_mod_reg_bits(OMAP3430_LOGICL1CACHERETSTATE,
> +			     (pwrst << __ffs(OMAP3430_LOGICL1CACHERETSTATE)),
> +			     pwrdm->prcm_offs, PM_PWSTCTRL);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_set_logic_retst);
> +
> +/**
> + * pwrdm_set_mem_onst - set memory power state while powerdomain ON
> + * @pwrdm: struct powerdomain * to set
> + * @bank: memory bank number to set (0-3)
> + * @pwrst: one of the PWRDM_POWER_* macros
> + *
> + * Set the next power state that memory bank x of the powerdomain
> + * pwrdm will enter when the powerdomain enters the ON state.  Bank
> + * will be a number from 0 to 3, and represents different types of
> + * memory, depending on the powerdomain.  Returns -EINVAL if the
> + * powerdomain pointer is null or the target power state is not not
> + * supported for this memory bank, -EEXIST if the target memory bank
> + * does not exist or is not controllable, or returns 0 upon success.
> + */
> +int pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
> +{
> +	u32 m;
> +
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	if (pwrdm->banks < (bank + 1))
> +		return -EEXIST;
> +
> +	if (!(pwrdm->pwrsts_mem_on[bank] & (1 << pwrst)))
> +		return -EINVAL;
> +
> +	pr_debug("powerdomain: setting next memory powerstate for domain %s "
> +		 "bank %0x while pwrdm-ON to %0x\n", pwrdm->name, bank, pwrst);
> +
> +	/*
> +	 * The register bit names below may not correspond to the
> +	 * actual names of the bits in each powerdomain's register,
> +	 * but the type of value returned is the same for each
> +	 * powerdomain.
> +	 */
> +	switch (bank) {
> +	case 0:
> +		m = OMAP3430_SHAREDL1CACHEFLATONSTATE_MASK;
> +		break;
> +	case 1:
> +		m = OMAP3430_L1FLATMEMONSTATE_MASK;
> +		break;
> +	case 2:
> +		m = OMAP3430_SHAREDL2CACHEFLATONSTATE_MASK;
> +		break;
> +	case 3:
> +		m = OMAP3430_L2FLATMEMONSTATE_MASK;
> +		break;
> +	default:
> +		WARN_ON(1); /* should never happen */
> +		return -EEXIST;
> +	}
> +
> +	prm_rmw_mod_reg_bits(m, (pwrst << __ffs(m)),
> +			     pwrdm->prcm_offs, PM_PWSTCTRL);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_set_mem_onst);
> +
> +/**
> + * pwrdm_set_mem_retst - set memory power state while powerdomain in RET
> + * @pwrdm: struct powerdomain * to set
> + * @bank: memory bank number to set (0-3)
> + * @pwrst: one of the PWRDM_POWER_* macros
> + *
> + * Set the next power state that memory bank x of the powerdomain
> + * pwrdm will enter when the powerdomain enters the RETENTION state.
> + * Bank will be a number from 0 to 3, and represents different types
> + * of memory, depending on the powerdomain.  pwrst will be either
> + * RETENTION or OFF, if supported. Returns -EINVAL if the powerdomain
> + * pointer is null or the target power state is not not supported for
> + * this memory bank, -EEXIST if the target memory bank does not exist
> + * or is not controllable, or returns 0 upon success.
> + */
> +int pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
> +{
> +	u32 m;
> +
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	if (pwrdm->banks < (bank + 1))
> +		return -EEXIST;
> +
> +	if (!(pwrdm->pwrsts_mem_ret[bank] & (1 << pwrst)))
> +		return -EINVAL;
> +
> +	pr_debug("powerdomain: setting next memory powerstate for domain %s "
> +		 "bank %0x while pwrdm-RET to %0x\n", pwrdm->name, bank, pwrst);
> +
> +	/*
> +	 * The register bit names below may not correspond to the
> +	 * actual names of the bits in each powerdomain's register,
> +	 * but the type of value returned is the same for each
> +	 * powerdomain.
> +	 */
> +	switch (bank) {
> +	case 0:
> +		m = OMAP3430_SHAREDL1CACHEFLATRETSTATE;
> +		break;
> +	case 1:
> +		m = OMAP3430_L1FLATMEMRETSTATE;
> +		break;
> +	case 2:
> +		m = OMAP3430_SHAREDL2CACHEFLATRETSTATE;
> +		break;
> +	case 3:
> +		m = OMAP3430_L2FLATMEMRETSTATE;
> +		break;
> +	default:
> +		WARN_ON(1); /* should never happen */
> +		return -EEXIST;
> +	}
> +
> +	prm_rmw_mod_reg_bits(m, (pwrst << __ffs(m)), pwrdm->prcm_offs,
> +			     PM_PWSTCTRL);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_set_mem_retst);
> +
> +/**
> + * pwrdm_read_logic_pwrst - get current powerdomain logic retention power state
> + * @pwrdm: struct powerdomain * to get current logic retention power state
> + *
> + * Return the current power state that the logic portion of
> + * powerdomain pwrdm will enter
> + * Returns -EINVAL if the powerdomain pointer is null or returns the
> + * current logic retention power state upon success.
> + */
> +int pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	return prm_read_mod_bits_shift(pwrdm->prcm_offs, PM_PWSTST,
> +					OMAP3430_LOGICSTATEST);
> +}
> +EXPORT_SYMBOL(pwrdm_read_logic_pwrst);
> +
> +/**
> + * pwrdm_read_prev_logic_pwrst - get previous powerdomain logic power state
> + * @pwrdm: struct powerdomain * to get previous logic power state
> + *
> + * Return the powerdomain pwrdm's logic power state.  Returns -EINVAL
> + * if the powerdomain pointer is null or returns the previous logic
> + * power state upon success.
> + */
> +int pwrdm_read_prev_logic_pwrst(struct powerdomain *pwrdm)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	/*
> +	 * The register bit names below may not correspond to the
> +	 * actual names of the bits in each powerdomain's register,
> +	 * but the type of value returned is the same for each
> +	 * powerdomain.
> +	 */
> +	return prm_read_mod_bits_shift(pwrdm->prcm_offs, OMAP3430_PM_PREPWSTST,
> +					OMAP3430_LASTLOGICSTATEENTERED);
> +}
> +EXPORT_SYMBOL(pwrdm_read_prev_logic_pwrst);
> +
> +/**
> + * pwrdm_read_mem_pwrst - get current memory bank power state
> + * @pwrdm: struct powerdomain * to get current memory bank power state
> + * @bank: memory bank number (0-3)
> + *
> + * Return the powerdomain pwrdm's current memory power state for bank
> + * x.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
> + * the target memory bank does not exist or is not controllable, or
> + * returns the current memory power state upon success.
> + */
> +int pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
> +{
> +	u32 m;
> +
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	if (pwrdm->banks < (bank + 1))
> +		return -EEXIST;
> +
> +	/*
> +	 * The register bit names below may not correspond to the
> +	 * actual names of the bits in each powerdomain's register,
> +	 * but the type of value returned is the same for each
> +	 * powerdomain.
> +	 */
> +	switch (bank) {
> +	case 0:
> +		m = OMAP3430_SHAREDL1CACHEFLATSTATEST_MASK;
> +		break;
> +	case 1:
> +		m = OMAP3430_L1FLATMEMSTATEST_MASK;
> +		break;
> +	case 2:
> +		m = OMAP3430_SHAREDL2CACHEFLATSTATEST_MASK;
> +		break;
> +	case 3:
> +		m = OMAP3430_L2FLATMEMSTATEST_MASK;
> +		break;
> +	default:
> +		WARN_ON(1); /* should never happen */
> +		return -EEXIST;
> +	}
> +
> +	return prm_read_mod_bits_shift(pwrdm->prcm_offs, PM_PWSTST, m);
> +}
> +EXPORT_SYMBOL(pwrdm_read_mem_pwrst);
> +
> +/**
> + * pwrdm_read_prev_mem_pwrst - get previous memory bank power state
> + * @pwrdm: struct powerdomain * to get previous memory bank power state
> + * @bank: memory bank number (0-3)
> + *
> + * Return the powerdomain pwrdm's previous memory power state for bank
> + * x.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
> + * the target memory bank does not exist or is not controllable, or
> + * returns the previous memory power state upon success.
> + */
> +int pwrdm_read_prev_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
> +{
> +	u32 m;
> +
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	if (pwrdm->banks < (bank + 1))
> +		return -EEXIST;
> +
> +	/*
> +	 * The register bit names below may not correspond to the actual
> +	 * names of the bits in each powerdomain's register,
> +	 * but the type of value returned is the same for each powerdomain.
> +	 */
> +	switch (bank) {
> +	case 0:
> +		m = OMAP3430_LASTMEM1STATEENTERED_MASK;
> +		break;
> +	case 1:
> +		m = OMAP3430_LASTMEM2STATEENTERED_MASK;
> +		break;
> +	case 2:
> +		m = OMAP3430_LASTSHAREDL2CACHEFLATSTATEENTERED_MASK;
> +		break;
> +	case 3:
> +		m = OMAP3430_LASTL2FLATMEMSTATEENTERED_MASK;
> +		break;
> +	default:
> +		WARN_ON(1); /* should never happen */
> +		return -EEXIST;
> +	}
> +
> +	return prm_read_mod_bits_shift(pwrdm->prcm_offs,
> +					OMAP3430_PM_PREPWSTST, m);
> +}
> +EXPORT_SYMBOL(pwrdm_read_prev_mem_pwrst);
> +
> +/**
> + * pwrdm_clear_all_prev_pwrst - clear previous powerstate register for a pwrdm
> + * @pwrdm: struct powerdomain * to clear
> + *
> + * Clear the powerdomain's previous power state register.  Clears the
> + * entire register, including logic and memory bank previous power states.
> + * Returns -EINVAL if the powerdomain pointer is null, or returns 0 upon
> + * success.
> + */
> +int pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
> +{
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	/*
> +	 * XXX should get the powerdomain's current state here;
> +	 * warn & fail if it is not ON.
> +	 */
> +
> +	pr_debug("powerdomain: clearing previous power state reg for %s\n",
> +		 pwrdm->name);
> +
> +	prm_write_mod_reg(0, pwrdm->prcm_offs, OMAP3430_PM_PREPWSTST);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_clear_all_prev_pwrst);
> +
> +/**
> + * pwrdm_wait_transition - wait for powerdomain power transition to finish
> + * @pwrdm: struct powerdomain * to wait for
> + *
> + * If the powerdomain pwrdm is in the process of a state transition,
> + * spin until it completes the power transition, or until an iteration
> + * bailout value is reached. Returns -EINVAL if the powerdomain
> + * pointer is null, -EAGAIN if the bailout value was reached, or
> + * returns 0 upon success.
> + */
> +int pwrdm_wait_transition(struct powerdomain *pwrdm)
> +{
> +	u32 c = 0;
> +
> +	if (!pwrdm)
> +		return -EINVAL;
> +
> +	/*
> +	 * 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 ((prm_read_mod_reg(pwrdm->prcm_offs, PM_PWSTST) &
> +		OMAP_INTRANSITION) &&
> +	       (c++ < PWRDM_TRANSITION_BAILOUT))
> +		udelay(1);
> +
> +	if (c >= PWRDM_TRANSITION_BAILOUT) {
> +		printk(KERN_ERR "powerdomain: waited too long for "
> +		       "powerdomain %s to complete transition\n", pwrdm->name);
> +		return -EAGAIN;
> +	}
> +
> +	pr_debug("powerdomain: completed transition in %d loops\n", c);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pwrdm_wait_transition);
> +
> +
> Index: linux-omap/arch/arm/plat-omap/Kconfig
> ===================================================================
> --- linux-omap.orig/arch/arm/plat-omap/Kconfig	2008-04-10 08:00:56.000000000 -0600
> +++ linux-omap/arch/arm/plat-omap/Kconfig	2008-04-10 08:00:58.000000000 -0600
> @@ -42,6 +42,18 @@
>  	  confident in your SRAM code, disabling this will save
>  	  about 600 bytes.
>  
> +config OMAP_DEBUG_POWERDOMAIN
> +	bool "Emit debug messages from powerdomain layer"
> +	depends on ARCH_OMAP2 || ARCH_OMAP3
> +	default n
> +	help
> +	  Say Y here if you want to compile in powerdomain layer
> +	  debugging messages for OMAP2/3.   These messages can
> +	  provide more detail as to why some powerdomain calls
> +	  may be failing, and will also emit a descriptive message
> +	  for every powerdomain register write.  However, the
> +	  extra detail costs some memory.
> +
>  config OMAP_RESET_CLOCKS
>  	bool "Reset unused clocks during boot"
>  	depends on ARCH_OMAP
> Index: linux-omap/include/asm-arm/arch-omap/powerdomain.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-omap/include/asm-arm/arch-omap/powerdomain.h	2008-04-10 08:00:58.000000000 -0600
> @@ -0,0 +1,137 @@
> +/*
> + * OMAP2/3 powerdomain control
> + *
> + * Copyright (C) 2007-8 Texas Instruments, Inc.
> + * Copyright (C) 2007-8 Nokia Corporation
> + *
> + * Written by Paul Walmsley
> + *
> + * 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.
> + */
> +
> +#ifndef ASM_ARM_ARCH_OMAP_POWERDOMAIN
> +#define ASM_ARM_ARCH_OMAP_POWERDOMAIN
> +
> +#include <linux/types.h>
> +#include <linux/list.h>
> +
> +#include <asm/atomic.h>
> +
> +#include <asm/arch/cpu.h>
> +
> +
> +/* Powerdomain basic power states */
> +#define PWRDM_POWER_OFF		0x0
> +#define PWRDM_POWER_RET		0x1
> +#define PWRDM_POWER_INACTIVE	0x2
> +#define PWRDM_POWER_ON		0x3
> +
> +/* Powerdomain allowable state bitfields */
> +#define PWRSTS_OFF_ON		((1 << PWRDM_POWER_OFF) | \
> +				 (1 << PWRDM_POWER_ON))
> +
> +#define PWRSTS_OFF_RET		((1 << PWRDM_POWER_OFF) | \
> +				 (1 << PWRDM_POWER_RET))
> +
> +#define PWRSTS_OFF_RET_ON	(PWRSTS_OFF_RET | (1 << PWRDM_POWER_ON))
> +
> +
> +/*
> + * Number of memory banks that are power-controllable.	On OMAP3430, the
> + * maximum is 4.
> + */
> +#define PWRDM_MAX_MEM_BANKS	4
> +
> +/* XXX A completely arbitrary number. What is reasonable here? */
> +#define PWRDM_TRANSITION_BAILOUT 100000
> +
> +struct powerdomain;
> +
> +/* Encodes dependencies between powerdomains - statically defined */
> +struct pwrdm_dep {
> +
> +	struct powerdomain *pwrdm;
> +
> +	/* Flags to mark OMAP chip restrictions, etc. */
> +	const omap_chip_t omap_chip;
> +
> +};
> +
> +struct powerdomain {
> +
> +	/* Powerdomain name */
> +	const char *name;
> +
> +	/* the address offset from CM_BASE/PRM_BASE */
> +	const s16 prcm_offs;
> +
> +	/* Used to represent the OMAP chip types containing this pwrdm */
> +	const omap_chip_t omap_chip;
> +
> +	/* Bit shift of this powerdomain's PM_WKDEP/CM_SLEEPDEP bit */
> +	const u8 dep_bit;
> +
> +	/* Powerdomains that can be told to wake this powerdomain up */
> +	const struct pwrdm_dep *wkdep_srcs;
> +
> +	/* Powerdomains that can be told to keep this pwrdm from inactivity */
> +	const struct pwrdm_dep *sleepdep_srcs;
> +
> +	/* Possible powerdomain power states */
> +	const u8 pwrsts;
> +
> +	/* Possible logic power states when pwrdm in RETENTION */
> +	const u8 pwrsts_logic_ret;
> +
> +	/* Number of software-controllable memory banks in this powerdomain */
> +	const u8 banks;
> +
> +	/* Possible memory bank pwrstates when pwrdm in RETENTION */
> +	const u8 pwrsts_mem_ret[PWRDM_MAX_MEM_BANKS];
> +
> +	/* Possible memory bank pwrstates when pwrdm is ON */
> +	const u8 pwrsts_mem_on[PWRDM_MAX_MEM_BANKS];
> +
> +	/* List of clockdomains in this powerdomain */
> +	struct list_head pwrdm_clkdms;
> +
> +	struct kobject *kobj;
> +	struct list_head node;
> +
> +};
> +
> +
> +void pwrdm_init(struct powerdomain **pwrdm_list);
> +
> +int pwrdm_register(struct powerdomain *pwrdm);
> +int pwrdm_unregister(struct powerdomain *pwrdm);
> +struct powerdomain *pwrdm_lookup(const char *name);
> +
> +int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm));
> +
> +int pwrdm_add_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2);
> +int pwrdm_del_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2);
> +int pwrdm_read_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2);
> +int pwrdm_add_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2);
> +int pwrdm_del_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2);
> +int pwrdm_read_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2);
> +
> +int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst);
> +int pwrdm_read_next_pwrst(struct powerdomain *pwrdm);
> +int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm);
> +int pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm);
> +
> +int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst);
> +int pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank, u8 pwrst);
> +int pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank, u8 pwrst);
> +
> +int pwrdm_read_logic_pwrst(struct powerdomain *pwrdm);
> +int pwrdm_read_prev_logic_pwrst(struct powerdomain *pwrdm);
> +int pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank);
> +int pwrdm_read_prev_mem_pwrst(struct powerdomain *pwrdm, u8 bank);
> +
> +int pwrdm_wait_transition(struct powerdomain *pwrdm);
> +
> +#endif
> 
> -- 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html