/*
* OMAP2/3/4 clockdomain framework functions
*
* Copyright (C) 2008-2010 Texas Instruments, Inc.
* Copyright (C) 2008-2010 Nokia Corporation
*
* Written by Paul Walmsley and Jouni Högander
* Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@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.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/limits.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <plat/clock.h>
#include "clockdomain.h"
/* clkdm_list contains all registered struct clockdomains */
static LIST_HEAD(clkdm_list);
/* array of clockdomain deps to be added/removed when clkdm in hwsup mode */
static struct clkdm_autodep *autodeps;
static struct clkdm_ops *arch_clkdm;
/* Private functions */
static struct clockdomain *_clkdm_lookup(const char *name)
{
struct clockdomain *clkdm, *temp_clkdm;
if (!name)
return NULL;
clkdm = NULL;
list_for_each_entry(temp_clkdm, &clkdm_list, node) {
if (!strcmp(name, temp_clkdm->name)) {
clkdm = temp_clkdm;
break;
}
}
return clkdm;
}
/**
* _clkdm_register - register a clockdomain
* @clkdm: struct clockdomain * to register
*
* Adds a clockdomain to the internal clockdomain list.
* Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
* already registered by the provided name, or 0 upon success.
*/
static int _clkdm_register(struct clockdomain *clkdm)
{
struct powerdomain *pwrdm;
if (!clkdm || !clkdm->name)
return -EINVAL;
if (!omap_chip_is(clkdm->omap_chip))
return -EINVAL;
pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
if (!pwrdm) {
pr_err("clockdomain: %s: powerdomain %s does not exist\n",
clkdm->name, clkdm->pwrdm.name);
return -EINVAL;
}
clkdm->pwrdm.ptr = pwrdm;
/* Verify that the clockdomain is not already registered */
if (_clkdm_lookup(clkdm->name))
return -EEXIST;
list_add(&clkdm->node, &clkdm_list);
pwrdm_add_clkdm(pwrdm, clkdm);
pr_debug("clockdomain: registered %s\n", clkdm->name);
return 0;
}
/* _clkdm_deps_lookup - look up the specified clockdomain in a clkdm list */
static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
struct clkdm_dep *deps)
{
struct clkdm_dep *cd;
if (!clkdm || !deps || !omap_chip_is(clkdm->omap_chip))
return ERR_PTR(-EINVAL);
for (cd = deps; cd->clkdm_name; cd++) {
if (!omap_chip_is(cd->omap_chip))
continue;
if (!cd->clkdm && cd->clkdm_name)
cd->clkdm = _clkdm_lookup(cd->clkdm_name);
if (cd->clkdm == clkdm)
break;
}
if (!cd->clkdm_name)
return ERR_PTR(-ENOENT);
return cd;
}
/*
* _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store
* @autodep: struct clkdm_autodep * to resolve
*
* Resolve autodep clockdomain names to clockdomain pointers via
* clkdm_lookup() and store the pointers in the autodep structure. An
* "autodep" is a clockdomain sleep/wakeup dependency that is
* automatically added and removed whenever clocks in the associated
* clockdomain are enabled or disabled (respectively) when the
* clockdomain is in hardware-supervised mode. Meant to be called
* once at clockdomain layer initialization, since these should remain
* fixed for a particular architecture. No return value.
*
* XXX autodeps are deprecated and should be removed at the earliest
* opportunity
*/
static void _autodep_lookup(struct clkdm_autodep *autodep)
{
struct clockdomain *clkdm;
if (!autodep)
return;
if (!omap_chip_is(autodep->omap_chip))
return;
clkdm = clkdm_lookup(autodep->clkdm.name);
if (!clkdm) {
pr_err("clockdomain: autodeps: clockdomain %s does not exist\n",
autodep->clkdm.name);
clkdm = ERR_PTR(-ENOENT);
}
autodep->clkdm.ptr = clkdm;
}
/*
* _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
* @clkdm: struct clockdomain *
*
* Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
* in hardware-supervised mode. Meant to be called from clock framework
* when a clock inside clockdomain 'clkdm' is enabled. No return value.
*
* XXX autodeps are deprecated and should be removed at the earliest
* opportunity
*/
void _clkdm_add_autodeps(struct clockdomain *clkdm)
{
struct clkdm_autodep *autodep;
if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
return;
for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
if (IS_ERR(autodep->clkdm.ptr))
continue;
if (!omap_chip_is(autodep->omap_chip))
continue;
pr_debug("clockdomain: adding %s sleepdep/wkdep for "
"clkdm %s\n", autodep->clkdm.ptr->name,
clkdm->name);
clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
}
}
/*
* _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
* @clkdm: struct clockdomain *
*
* Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
* in hardware-supervised mode. Meant to be called from clock framework
* when a clock inside clockdomain 'clkdm' is disabled. No return value.
*
* XXX autodeps are deprecated and should be removed at the earliest
* opportunity
*/
void _clkdm_del_autodeps(struct clockdomain *clkdm)
{
struct clkdm_autodep *autodep;
if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
return;
for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
if (IS_ERR(autodep->clkdm.ptr))
continue;
if (!omap_chip_is(autodep->omap_chip))
continue;
pr_debug("clockdomain: removing %s sleepdep/wkdep for "
"clkdm %s\n", autodep->clkdm.ptr->name,
clkdm->name);
clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
}
}
/**
* _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms
* @clkdm: clockdomain that we are resolving dependencies for
* @clkdm_deps: ptr to array of struct clkdm_deps to resolve
*
* Iterates through @clkdm_deps, looking up the struct clockdomain named by
* clkdm_name and storing the clockdomain pointer in the struct clkdm_dep.
* No return value.
*/
static void _resolve_clkdm_deps(struct clockdomain *clkdm,
struct clkdm_dep *clkdm_deps)
{
struct clkdm_dep *cd;
for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) {
if (!omap_chip_is(cd->omap_chip))
continue;
if (cd->clkdm)
continue;
cd->clkdm = _clkdm_lookup(cd->clkdm_name);
WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen",
clkdm->name, cd->clkdm_name);
}
}
/* Public functions */
/**
* clkdm_init - set up the clockdomain layer
* @clkdms: optional pointer to an array of clockdomains to register
* @init_autodeps: optional pointer to an array of autodeps to register
* @custom_funcs: func pointers for arch specific implementations
*
* Set up internal state. If a pointer to an array of clockdomains
* @clkdms was supplied, loop through the list of clockdomains,
* register all that are available on the current platform. Similarly,
* if a pointer to an array of clockdomain autodependencies
* @init_autodeps was provided, register those. No return value.
*/
void clkdm_init(struct clockdomain **clkdms,
struct clkdm_autodep *init_autodeps,
struct clkdm_ops *custom_funcs)
{
struct clockdomain **c = NULL;
struct clockdomain *clkdm;
struct clkdm_autodep *autodep = NULL;
if (!custom_funcs)
WARN(1, "No custom clkdm functions registered\n");
else
arch_clkdm = custom_funcs;
if (clkdms)
for (c = clkdms; *c; c++)
_clkdm_register(*c);
autodeps = init_autodeps;
if (autodeps)
for (autodep = autodeps; autodep->clkdm.ptr; autodep++)
_autodep_lookup(autodep);
/*
* Put all clockdomains into software-supervised mode; PM code
* should later enable hardware-supervised mode as appropriate
*/
list_for_each_entry(clkdm, &clkdm_list, node) {
if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
clkdm_wakeup(clkdm);
else if (clkdm->flags & CLKDM_CAN_DISABLE_AUTO)
clkdm_deny_idle(clkdm);
_resolve_clkdm_deps(clkdm, clkdm->wkdep_srcs);
clkdm_clear_all_wkdeps(clkdm);
_resolve_clkdm_deps(clkdm, clkdm->sleepdep_srcs);
clkdm_clear_all_sleepdeps(clkdm);
}
}
/**
* clkdm_lookup - look up a clockdomain by name, return a pointer
* @name: name of clockdomain
*
* Find a registered clockdomain by its name @name. Returns a pointer
* to the struct clockdomain if found, or NULL otherwise.
*/
struct clockdomain *clkdm_lookup(const char *name)
{
struct clockdomain *clkdm, *temp_clkdm;
if (!name)
return NULL;
clkdm = NULL;
list_for_each_entry(temp_clkdm, &clkdm_list, node) {
if (!strcmp(name, temp_clkdm->name)) {
clkdm = temp_clkdm;
break;
}
}
return clkdm;
}
/**
* clkdm_for_each - call function on each registered clockdomain
* @fn: callback function *
*
* Call the supplied function @fn for each registered clockdomain.
* The callback function @fn can return anything but 0 to bail
* out early from the iterator. The callback function is called with
* the clkdm_mutex held, so no clockdomain structure manipulation
* functions should be called from the callback, although hardware
* clockdomain 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 clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
void *user)
{
struct clockdomain *clkdm;
int ret = 0;
if (!fn)
return -EINVAL;
list_for_each_entry(clkdm, &clkdm_list, node) {
ret = (*fn)(clkdm, user);
if (ret)
break;
}
return ret;
}
/**
* clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
* @clkdm: struct clockdomain *
*
* Return a pointer to the struct powerdomain that the specified clockdomain
* @clkdm exists in, or returns NULL if @clkdm is NULL.
*/
struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
{
if (!clkdm)
return NULL;
return clkdm->pwrdm.ptr;
}
/* Hardware clockdomain control */
/**
* clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1
* @clkdm1: wake this struct clockdomain * up (dependent)
* @clkdm2: when this struct clockdomain * wakes up (source)
*
* When the clockdomain represented by @clkdm2 wakes up, wake up
* @clkdm1. Implemented in hardware on the OMAP, this feature is
* designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
* Returns -EINVAL if presented with invalid clockdomain pointers,
* -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
* success.
*/
int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
{
struct clkdm_dep *cd;
int ret = 0;
if (!clkdm1 || !clkdm2)
return -EINVAL;
cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
if (IS_ERR(cd))
ret = PTR_ERR(cd);
if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep)
ret = -EINVAL;
if (ret) {
pr_debug("clockdomain: hardware cannot set/clear wake up of "
"%s when %s wakes up\n", clkdm1->name, clkdm2->name);
return ret;
}
if (atomic_inc_return(&cd->wkdep_usecount) == 1) {
pr_debug("clockdomain: hardware will wake up %s when %s wakes "
"up\n", clkdm1->name, clkdm2->name);
ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2);
}
return ret;
}
/**
* clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1
* @clkdm1: wake this struct clockdomain * up (dependent)
* @clkdm2: when this struct clockdomain * wakes up (source)
*
* Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
* wakes up. Returns -EINVAL if presented with invalid clockdomain
* pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
* 0 upon success.
*/
int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
{
struct clkdm_dep *cd;
int ret = 0;
if (!clkdm1 || !clkdm2)
return -EINVAL;
cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
if (IS_ERR(cd))
ret = PTR_ERR(cd);
if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep)
ret = -EINVAL;
if (ret) {
pr_debug("clockdomain: hardware cannot set/clear wake up of "
"%s when %s wakes up\n", clkdm1->name, clkdm2->name);
return ret;
}
if (atomic_dec_return(&cd->wkdep_usecount) == 0) {
pr_debug("clockdomain: hardware will no longer wake up %s "
"after %s wakes up\n", clkdm1->name, clkdm2->name);
ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2);
}
return ret;
}
/**
* clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1
* @clkdm1: wake this struct clockdomain * up (dependent)
* @clkdm2: when this struct clockdomain * wakes up (source)
*
* Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be
* awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL
* if either clockdomain 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 clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
{
struct clkdm_dep *cd;
int ret = 0;
if (!clkdm1 || !clkdm2)
return -EINVAL;
cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
if (IS_ERR(cd))
ret = PTR_ERR(cd);
if (!arch_clkdm || !arch_clkdm->clkdm_read_wkdep)
ret = -EINVAL;
if (ret) {
pr_debug("clockdomain: hardware cannot set/clear wake up of "
"%s when %s wakes up\n", clkdm1->name, clkdm2->name);
return ret;
}
/* XXX It's faster to return the atomic wkdep_usecount */
return arch_clkdm->clkdm_read_wkdep(clkdm1, clkdm2);
}
/**
* clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm
* @clkdm: struct clockdomain * to remove all wakeup dependencies from
*
* Remove all inter-clockdomain wakeup dependencies that could cause
* @clkdm to wake. Intended to be used during boot to initialize the
* PRCM to a known state, after all clockdomains are put into swsup idle
* and woken up. Returns -EINVAL if @clkdm pointer is invalid, or
* 0 upon success.
*/
int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
{
if (!clkdm)
return -EINVAL;
if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_wkdeps)
return -EINVAL;
return arch_clkdm->clkdm_clear_all_wkdeps(clkdm);
}
/**
* clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1
* @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
* @clkdm2: when this struct clockdomain * is active (source)
*
* Prevent @clkdm1 from automatically going inactive (and then to
* retention or off) if @clkdm2 is active. Returns -EINVAL if
* presented with invalid clockdomain 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 clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
{
struct clkdm_dep *cd;
int ret = 0;
if (!clkdm1 || !clkdm2)
return -EINVAL;
cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
if (IS_ERR(cd))
ret = PTR_ERR(cd);
if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep)
ret = -EINVAL;
if (ret) {
pr_debug("clockdomain: hardware cannot set/clear sleep "
"dependency affecting %s from %s\n", clkdm1->name,
clkdm2->name);
return ret;
}
if (atomic_inc_return(&cd->sleepdep_usecount) == 1) {
pr_debug("clockdomain: will prevent %s from sleeping if %s "
"is active\n", clkdm1->name, clkdm2->name);
ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2);
}
return ret;
}
/**
* clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1
* @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
* @clkdm2: when this struct clockdomain * is active (source)
*
* Allow @clkdm1 to automatically go inactive (and then to retention or
* off), independent of the activity state of @clkdm2. Returns -EINVAL
* if presented with invalid clockdomain 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 clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
{
struct clkdm_dep *cd;
int ret = 0;
if (!clkdm1 || !clkdm2)
return -EINVAL;
cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
if (IS_ERR(cd))
ret = PTR_ERR(cd);
if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep)
ret = -EINVAL;
if (ret) {
pr_debug("clockdomain: hardware cannot set/clear sleep "
"dependency affecting %s from %s\n", clkdm1->name,
clkdm2->name);
return ret;
}
if (atomic_dec_return(&cd->sleepdep_usecount) == 0) {
pr_debug("clockdomain: will no longer prevent %s from "
"sleeping if %s is active\n", clkdm1->name,
clkdm2->name);
ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2);
}
return ret;
}
/**
* clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1
* @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
* @clkdm2: when this struct clockdomain * is active (source)
*
* Return 1 if a hardware sleep dependency exists wherein @clkdm1 will
* not be allowed to automatically go inactive if @clkdm2 is active;
* 0 if @clkdm1's automatic power state inactivity transition is independent
* of @clkdm2's; -EINVAL if either clockdomain 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 clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
{
struct clkdm_dep *cd;
int ret = 0;
if (!clkdm1 || !clkdm2)
return -EINVAL;
cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
if (IS_ERR(cd))
ret = PTR_ERR(cd);
if (!arch_clkdm || !arch_clkdm->clkdm_read_sleepdep)
ret = -EINVAL;
if (ret) {
pr_debug("clockdomain: hardware cannot set/clear sleep "
"dependency affecting %s from %s\n", clkdm1->name,
clkdm2->name);
return ret;
}
/* XXX It's faster to return the atomic sleepdep_usecount */
return arch_clkdm->clkdm_read_sleepdep(clkdm1, clkdm2);
}
/**
* clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm
* @clkdm: struct clockdomain * to remove all sleep dependencies from
*
* Remove all inter-clockdomain sleep dependencies that could prevent
* @clkdm from idling. Intended to be used during boot to initialize the
* PRCM to a known state, after all clockdomains are put into swsup idle
* and woken up. Returns -EINVAL if @clkdm pointer is invalid, or
* 0 upon success.
*/
int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
{
if (!clkdm)
return -EINVAL;
if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_sleepdeps)
return -EINVAL;
return arch_clkdm->clkdm_clear_all_sleepdeps(clkdm);
}
/**
* clkdm_sleep - force clockdomain sleep transition
* @clkdm: struct clockdomain *
*
* Instruct the CM to force a sleep transition on the specified
* clockdomain @clkdm. Returns -EINVAL if @clkdm is NULL or if
* clockdomain does not support software-initiated sleep; 0 upon
* success.
*/
int clkdm_sleep(struct clockdomain *clkdm)
{
if (!clkdm)
return -EINVAL;
if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
pr_debug("clockdomain: %s does not support forcing "
"sleep via software\n", clkdm->name);
return -EINVAL;
}
if (!arch_clkdm || !arch_clkdm->clkdm_sleep)
return -EINVAL;
pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
return arch_clkdm->clkdm_sleep(clkdm);
}
/**
* clkdm_wakeup - force clockdomain wakeup transition
* @clkdm: struct clockdomain *
*
* Instruct the CM to force a wakeup transition on the specified
* clockdomain @clkdm. Returns -EINVAL if @clkdm is NULL or if the
* clockdomain does not support software-controlled wakeup; 0 upon
* success.
*/
int clkdm_wakeup(struct clockdomain *clkdm)
{
if (!clkdm)
return -EINVAL;
if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
pr_debug("clockdomain: %s does not support forcing "
"wakeup via software\n", clkdm->name);
return -EINVAL;
}
if (!arch_clkdm || !arch_clkdm->clkdm_wakeup)
return -EINVAL;
pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
return arch_clkdm->clkdm_wakeup(clkdm);
}
/**
* clkdm_allow_idle - enable hwsup idle transitions for clkdm
* @clkdm: struct clockdomain *
*
* Allow the hardware to automatically switch the clockdomain @clkdm into
* active or idle states, as needed by downstream clocks. If the
* clockdomain has any downstream clocks enabled in the clock
* framework, wkdep/sleepdep autodependencies are added; this is so
* device drivers can read and write to the device. No return value.
*/
void clkdm_allow_idle(struct clockdomain *clkdm)
{
if (!clkdm)
return;
if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
pr_debug("clock: automatic idle transitions cannot be enabled "
"on clockdomain %s\n", clkdm->name);
return;
}
if (!arch_clkdm || !arch_clkdm->clkdm_allow_idle)
return;
pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
clkdm->name);
arch_clkdm->clkdm_allow_idle(clkdm);
pwrdm_clkdm_state_switch(clkdm);
}
/**
* clkdm_deny_idle - disable hwsup idle transitions for clkdm
* @clkdm: struct clockdomain *
*
* Prevent the hardware from automatically switching the clockdomain
* @clkdm into inactive or idle states. If the clockdomain has
* downstream clocks enabled in the clock framework, wkdep/sleepdep
* autodependencies are removed. No return value.
*/
void clkdm_deny_idle(struct clockdomain *clkdm)
{
if (!clkdm)
return;
if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
pr_debug("clockdomain: automatic idle transitions cannot be "
"disabled on %s\n", clkdm->name);
return;
}
if (!arch_clkdm || !arch_clkdm->clkdm_deny_idle)
return;
pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
clkdm->name);
arch_clkdm->clkdm_deny_idle(clkdm);
}
/* Clockdomain-to-clock framework interface code */
/**
* clkdm_clk_enable - add an enabled downstream clock to this clkdm
* @clkdm: struct clockdomain *
* @clk: struct clk * of the enabled downstream clock
*
* Increment the usecount of the clockdomain @clkdm and ensure that it
* is awake before @clk is enabled. Intended to be called by
* clk_enable() code. If the clockdomain is in software-supervised
* idle mode, force the clockdomain to wake. If the clockdomain is in
* hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to
* ensure that devices in the clockdomain can be read from/written to
* by on-chip processors. Returns -EINVAL if passed null pointers;
* returns 0 upon success or if the clockdomain is in hwsup idle mode.
*/
int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
{
/*
* XXX Rewrite this code to maintain a list of enabled
* downstream clocks for debugging purposes?
*/
if (!clkdm || !clk)
return -EINVAL;
if (!arch_clkdm || !arch_clkdm->clkdm_clk_enable)
return -EINVAL;
if (atomic_inc_return(&clkdm->usecount) > 1)
return 0;
/* Clockdomain now has one enabled downstream clock */
pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
clk->name);
arch_clkdm->clkdm_clk_enable(clkdm);
pwrdm_wait_transition(clkdm->pwrdm.ptr);
pwrdm_clkdm_state_switch(clkdm);
return 0;
}
/**
* clkdm_clk_disable - remove an enabled downstream clock from this clkdm
* @clkdm: struct clockdomain *
* @clk: struct clk * of the disabled downstream clock
*
* Decrement the usecount of this clockdomain @clkdm when @clk is
* disabled. Intended to be called by clk_disable() code. If the
* clockdomain usecount goes to 0, put the clockdomain to sleep
* (software-supervised mode) or remove the clkdm autodependencies
* (hardware-supervised mode). Returns -EINVAL if passed null
* pointers; -ERANGE if the @clkdm usecount underflows and debugging
* is enabled; or returns 0 upon success or if the clockdomain is in
* hwsup idle mode.
*/
int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
{
/*
* XXX Rewrite this code to maintain a list of enabled
* downstream clocks for debugging purposes?
*/
if (!clkdm || !clk)
return -EINVAL;
if (!arch_clkdm || !arch_clkdm->clkdm_clk_disable)
return -EINVAL;
#ifdef DEBUG
if (atomic_read(&clkdm->usecount) == 0) {
WARN_ON(1); /* underflow */
return -ERANGE;
}
#endif
if (atomic_dec_return(&clkdm->usecount) > 0)
return 0;
/* All downstream clocks of this clockdomain are now disabled */
pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
clk->name);
arch_clkdm->clkdm_clk_disable(clkdm);
pwrdm_clkdm_state_switch(clkdm);
return 0;
}
