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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * OMAP2/3/4 clockdomain framework functions
  *
  * Copyright (C) 2008-2011 Texas Instruments, Inc.
  * Copyright (C) 2008-2011 Nokia Corporation
  *
  * Written by Paul Walmsley and Jouni Högander
  * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
  */
 #undef DEBUG
 
 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/delay.h>
 #include <linux/clk.h>
 #include <linux/limits.h>
 #include <linux/err.h>
 #include <linux/clk-provider.h>
 #include <linux/cpu_pm.h>
 
 #include <linux/io.h>
 
 #include <linux/bitops.h>
 
 #include "soc.h"
 #include "clock.h"
 #include "clockdomain.h"
 #include "pm.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;
 void clkdm_save_context(void);
 void clkdm_restore_context(void);
 
 /* 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;
 
     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)
         return ERR_PTR(-EINVAL);
 
     for (cd = deps; cd->clkdm_name; cd++) {
         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;
 
     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;
 }
 
 /**
  * _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 (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);
     }
 }
 
 /**
  * _clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1 (lockless)
  * @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.
  */
 static 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;
     }
 
     cd->wkdep_usecount++;
     if (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 dep from clkdm2 to clkdm1 (lockless)
  * @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.
  */
 static 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;
     }
 
     cd->wkdep_usecount--;
     if (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_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1 (lockless)
  * @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.
  */
 static 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;
     }
 
     cd->sleepdep_usecount++;
     if (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 dep from clkdm2 to clkdm1 (lockless)
  * @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.
  */
 static 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;
     }
 
     cd->sleepdep_usecount--;
     if (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;
 }
 
 /* Public functions */
 
 /**
  * clkdm_register_platform_funcs - register clockdomain implementation fns
  * @co: func pointers for arch specific implementations
  *
  * Register the list of function pointers used to implement the
  * clockdomain functions on different OMAP SoCs.  Should be called
  * before any other clkdm_register*() function.  Returns -EINVAL if
  * @co is null, -EEXIST if platform functions have already been
  * registered, or 0 upon success.
  */
 int clkdm_register_platform_funcs(struct clkdm_ops *co)
 {
     if (!co)
         return -EINVAL;
 
     if (arch_clkdm)
         return -EEXIST;
 
     arch_clkdm = co;
 
     return 0;
 };
 
 /**
  * clkdm_register_clkdms - register SoC clockdomains
  * @cs: pointer to an array of struct clockdomain to register
  *
  * Register the clockdomains available on a particular OMAP SoC.  Must
  * be called after clkdm_register_platform_funcs().  May be called
  * multiple times.  Returns -EACCES if called before
  * clkdm_register_platform_funcs(); -EINVAL if the argument @cs is
  * null; or 0 upon success.
  */
 int clkdm_register_clkdms(struct clockdomain **cs)
 {
     struct clockdomain **c = NULL;
 
     if (!arch_clkdm)
         return -EACCES;
 
     if (!cs)
         return -EINVAL;
 
     for (c = cs; *c; c++)
         _clkdm_register(*c);
 
     return 0;
 }
 
 /**
  * clkdm_register_autodeps - register autodeps (if required)
  * @ia: pointer to a static array of struct clkdm_autodep to register
  *
  * Register clockdomain "automatic dependencies."  These are
  * clockdomain wakeup and sleep dependencies that are automatically
  * added whenever the first clock inside a clockdomain is enabled, and
  * removed whenever the last clock inside a clockdomain is disabled.
  * These are currently only used on OMAP3 devices, and are deprecated,
  * since they waste energy.  However, until the OMAP2/3 IP block
  * enable/disable sequence can be converted to match the OMAP4
  * sequence, they are needed.
  *
  * Must be called only after all of the SoC clockdomains are
  * registered, since the function will resolve autodep clockdomain
  * names into clockdomain pointers.
  *
  * The struct clkdm_autodep @ia array must be static, as this function
  * does not copy the array elements.
  *
  * Returns -EACCES if called before any clockdomains have been
  * registered, -EINVAL if called with a null @ia argument, -EEXIST if
  * autodeps have already been registered, or 0 upon success.
  */
 int clkdm_register_autodeps(struct clkdm_autodep *ia)
 {
     struct clkdm_autodep *a = NULL;
 
     if (list_empty(&clkdm_list))
         return -EACCES;
 
     if (!ia)
         return -EINVAL;
 
     if (autodeps)
         return -EEXIST;
 
     autodeps = ia;
     for (a = autodeps; a->clkdm.ptr; a++)
         _autodep_lookup(a);
 
     return 0;
 }
 
 static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
 {
     switch (cmd) {
     case CPU_CLUSTER_PM_ENTER:
         if (enable_off_mode)
             clkdm_save_context();
         break;
     case CPU_CLUSTER_PM_EXIT:
         if (enable_off_mode)
             clkdm_restore_context();
         break;
     }
 
     return NOTIFY_OK;
 }
 
 /**
  * clkdm_complete_init - set up the clockdomain layer
  *
  * Put all clockdomains into software-supervised mode; PM code should
  * later enable hardware-supervised mode as appropriate.  Must be
  * called after clkdm_register_clkdms().  Returns -EACCES if called
  * before clkdm_register_clkdms(), or 0 upon success.
  */
 int clkdm_complete_init(void)
 {
     struct clockdomain *clkdm;
     static struct notifier_block nb;
 
     if (list_empty(&clkdm_list))
         return -EACCES;
 
     list_for_each_entry(clkdm, &clkdm_list, node) {
         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);
     }
 
     /* Only AM43XX can lose clkdm context during rtc-ddr suspend */
     if (soc_is_am43xx()) {
         nb.notifier_call = cpu_notifier;
         cpu_pm_register_notifier(&nb);
     }
 
     return 0;
 }
 
 /**
  * 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;
 
     if (!clkdm1 || !clkdm2)
         return -EINVAL;
 
     cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
     if (IS_ERR(cd))
         return PTR_ERR(cd);
 
     pwrdm_lock(cd->clkdm->pwrdm.ptr);
     ret = _clkdm_add_wkdep(clkdm1, clkdm2);
     pwrdm_unlock(cd->clkdm->pwrdm.ptr);
 
     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;
 
     if (!clkdm1 || !clkdm2)
         return -EINVAL;
 
     cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
     if (IS_ERR(cd))
         return PTR_ERR(cd);
 
     pwrdm_lock(cd->clkdm->pwrdm.ptr);
     ret = _clkdm_del_wkdep(clkdm1, clkdm2);
     pwrdm_unlock(cd->clkdm->pwrdm.ptr);
 
     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 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;
 
     if (!clkdm1 || !clkdm2)
         return -EINVAL;
 
     cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
     if (IS_ERR(cd))
         return PTR_ERR(cd);
 
     pwrdm_lock(cd->clkdm->pwrdm.ptr);
     ret = _clkdm_add_sleepdep(clkdm1, clkdm2);
     pwrdm_unlock(cd->clkdm->pwrdm.ptr);
 
     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;
 
     if (!clkdm1 || !clkdm2)
         return -EINVAL;
 
     cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
     if (IS_ERR(cd))
         return PTR_ERR(cd);
 
     pwrdm_lock(cd->clkdm->pwrdm.ptr);
     ret = _clkdm_del_sleepdep(clkdm1, clkdm2);
     pwrdm_unlock(cd->clkdm->pwrdm.ptr);
 
     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 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_nolock - force clockdomain sleep transition (lockless)
  * @clkdm: struct clockdomain *
  *
  * Instruct the CM to force a sleep transition on the specified
  * clockdomain @clkdm.  Only for use by the powerdomain code.  Returns
  * -EINVAL if @clkdm is NULL or if clockdomain does not support
  * software-initiated sleep; 0 upon success.
  */
 int clkdm_sleep_nolock(struct clockdomain *clkdm)
 {
     int ret;
 
     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);
 
     clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
     ret = arch_clkdm->clkdm_sleep(clkdm);
     ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 
     return ret;
 }
 
 /**
  * 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)
 {
     int ret;
 
     pwrdm_lock(clkdm->pwrdm.ptr);
     ret = clkdm_sleep_nolock(clkdm);
     pwrdm_unlock(clkdm->pwrdm.ptr);
 
     return ret;
 }
 
 /**
  * clkdm_wakeup_nolock - force clockdomain wakeup transition (lockless)
  * @clkdm: struct clockdomain *
  *
  * Instruct the CM to force a wakeup transition on the specified
  * clockdomain @clkdm.  Only for use by the powerdomain code.  Returns
  * -EINVAL if @clkdm is NULL or if the clockdomain does not support
  * software-controlled wakeup; 0 upon success.
  */
 int clkdm_wakeup_nolock(struct clockdomain *clkdm)
 {
     int ret;
 
     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);
 
     clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
     ret = arch_clkdm->clkdm_wakeup(clkdm);
     ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 
     return ret;
 }
 
 /**
  * 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)
 {
     int ret;
 
     pwrdm_lock(clkdm->pwrdm.ptr);
     ret = clkdm_wakeup_nolock(clkdm);
     pwrdm_unlock(clkdm->pwrdm.ptr);
 
     return ret;
 }
 
 /**
  * clkdm_allow_idle_nolock - 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.  Only for use by
  * the powerdomain code.  No return value.
  */
 void clkdm_allow_idle_nolock(struct clockdomain *clkdm)
 {
     if (!clkdm)
         return;
 
     if (!WARN_ON(!clkdm->forcewake_count))
         clkdm->forcewake_count--;
 
     if (clkdm->forcewake_count)
         return;
 
     if (!clkdm->usecount && (clkdm->flags & CLKDM_CAN_FORCE_SLEEP))
         clkdm_sleep_nolock(clkdm);
 
     if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO))
         return;
 
     if (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING)
         return;
 
     if (!arch_clkdm || !arch_clkdm->clkdm_allow_idle)
         return;
 
     pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
          clkdm->name);
 
     clkdm->_flags |= _CLKDM_FLAG_HWSUP_ENABLED;
     arch_clkdm->clkdm_allow_idle(clkdm);
     pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 }
 
 /**
  * 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)
 {
     pwrdm_lock(clkdm->pwrdm.ptr);
     clkdm_allow_idle_nolock(clkdm);
     pwrdm_unlock(clkdm->pwrdm.ptr);
 }
 
 /**
  * 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.  Only for use by the powerdomain
  * code.  No return value.
  */
 void clkdm_deny_idle_nolock(struct clockdomain *clkdm)
 {
     if (!clkdm)
         return;
 
     if (clkdm->forcewake_count++)
         return;
 
     if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
         clkdm_wakeup_nolock(clkdm);
 
     if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO))
         return;
 
     if (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING)
         return;
 
     if (!arch_clkdm || !arch_clkdm->clkdm_deny_idle)
         return;
 
     pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
          clkdm->name);
 
     clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
     arch_clkdm->clkdm_deny_idle(clkdm);
     pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 }
 
 /**
  * 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)
 {
     pwrdm_lock(clkdm->pwrdm.ptr);
     clkdm_deny_idle_nolock(clkdm);
     pwrdm_unlock(clkdm->pwrdm.ptr);
 }
 
 /**
  * clkdm_in_hwsup - is clockdomain @clkdm have hardware-supervised idle enabled?
  * @clkdm: struct clockdomain *
  *
  * Returns true if clockdomain @clkdm currently has
  * hardware-supervised idle enabled, or false if it does not or if
  * @clkdm is NULL.  It is only valid to call this function after
  * clkdm_init() has been called.  This function does not actually read
  * bits from the hardware; it instead tests an in-memory flag that is
  * changed whenever the clockdomain code changes the auto-idle mode.
  */
 bool clkdm_in_hwsup(struct clockdomain *clkdm)
 {
     bool ret;
 
     if (!clkdm)
         return false;
 
     ret = (clkdm->_flags & _CLKDM_FLAG_HWSUP_ENABLED) ? true : false;
 
     return ret;
 }
 
 /**
  * clkdm_missing_idle_reporting - can @clkdm enter autoidle even if in use?
  * @clkdm: struct clockdomain *
  *
  * Returns true if clockdomain @clkdm has the
  * CLKDM_MISSING_IDLE_REPORTING flag set, or false if not or @clkdm is
  * null.  More information is available in the documentation for the
  * CLKDM_MISSING_IDLE_REPORTING macro.
  */
 bool clkdm_missing_idle_reporting(struct clockdomain *clkdm)
 {
     if (!clkdm)
         return false;
 
     return (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING) ? true : false;
 }
 
 /* Public autodep handling functions (deprecated) */
 
 /**
  * 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;
 
         pr_debug("clockdomain: %s: adding %s sleepdep/wkdep\n",
              clkdm->name, autodep->clkdm.ptr->name);
 
         _clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
         _clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
     }
 }
 
 /**
  * clkdm_del_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;
 
         pr_debug("clockdomain: %s: removing %s sleepdep/wkdep\n",
              clkdm->name, autodep->clkdm.ptr->name);
 
         _clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
         _clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
     }
 }
 
 /* Clockdomain-to-clock/hwmod 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 *unused)
 {
     if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_enable)
         return -EINVAL;
 
     pwrdm_lock(clkdm->pwrdm.ptr);
 
     /*
      * For arch's with no autodeps, clkcm_clk_enable
      * should be called for every clock instance or hwmod that is
      * enabled, so the clkdm can be force woken up.
      */
     clkdm->usecount++;
     if (clkdm->usecount > 1 && autodeps) {
         pwrdm_unlock(clkdm->pwrdm.ptr);
         return 0;
     }
 
     arch_clkdm->clkdm_clk_enable(clkdm);
     pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
     pwrdm_unlock(clkdm->pwrdm.ptr);
 
     pr_debug("clockdomain: %s: enabled\n", clkdm->name);
 
     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; or returns 0
  * upon success or if the clockdomain is in hwsup idle mode.
  */
 int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
 {
     if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
         return -EINVAL;
 
     pwrdm_lock(clkdm->pwrdm.ptr);
 
     /* corner case: disabling unused clocks */
     if (clk && (__clk_get_enable_count(clk) == 0) && clkdm->usecount == 0)
         goto ccd_exit;
 
     if (clkdm->usecount == 0) {
         pwrdm_unlock(clkdm->pwrdm.ptr);
         WARN_ON(1); /* underflow */
         return -ERANGE;
     }
 
     clkdm->usecount--;
     if (clkdm->usecount > 0) {
         pwrdm_unlock(clkdm->pwrdm.ptr);
         return 0;
     }
 
     arch_clkdm->clkdm_clk_disable(clkdm);
     pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 
     pr_debug("clockdomain: %s: disabled\n", clkdm->name);
 
 ccd_exit:
     pwrdm_unlock(clkdm->pwrdm.ptr);
 
     return 0;
 }
 
 /**
  * clkdm_hwmod_enable - add an enabled downstream hwmod to this clkdm
  * @clkdm: struct clockdomain *
  * @oh: struct omap_hwmod * of the enabled downstream hwmod
  *
  * Increment the usecount of the clockdomain @clkdm and ensure that it
  * is awake before @oh is enabled. Intended to be called by
  * module_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_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh)
 {
     /* The clkdm attribute does not exist yet prior OMAP4 */
     if (cpu_is_omap24xx() || cpu_is_omap34xx())
         return 0;
 
     /*
      * XXX Rewrite this code to maintain a list of enabled
      * downstream hwmods for debugging purposes?
      */
 
     if (!oh)
         return -EINVAL;
 
     return clkdm_clk_enable(clkdm, NULL);
 }
 
 /**
  * clkdm_hwmod_disable - remove an enabled downstream hwmod from this clkdm
  * @clkdm: struct clockdomain *
  * @oh: struct omap_hwmod * of the disabled downstream hwmod
  *
  * Decrement the usecount of this clockdomain @clkdm when @oh is
  * disabled. Intended to be called by module_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; or returns 0 upon success or if the clockdomain is in hwsup
  * idle mode.
  */
 int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
 {
     /* The clkdm attribute does not exist yet prior OMAP4 */
     if (cpu_is_omap24xx() || cpu_is_omap34xx())
         return 0;
 
     if (!oh)
         return -EINVAL;
 
     return clkdm_clk_disable(clkdm, NULL);
 }
 
 /**
  * _clkdm_save_context - save the context for the control of this clkdm
  *
  * Due to a suspend or hibernation operation, the state of the registers
  * controlling this clkdm will be lost, save their context.
  */
 static int _clkdm_save_context(struct clockdomain *clkdm, void *unused)
 {
     if (!arch_clkdm || !arch_clkdm->clkdm_save_context)
         return -EINVAL;
 
     return arch_clkdm->clkdm_save_context(clkdm);
 }
 
 /**
  * _clkdm_restore_context - restore context for control of this clkdm
  *
  * Restore the register values for this clockdomain.
  */
 static int _clkdm_restore_context(struct clockdomain *clkdm, void *unused)
 {
     if (!arch_clkdm || !arch_clkdm->clkdm_restore_context)
         return -EINVAL;
 
     return arch_clkdm->clkdm_restore_context(clkdm);
 }
 
 /**
  * clkdm_save_context - Saves the context for each registered clkdm
  *
  * Save the context for each registered clockdomain.
  */
 void clkdm_save_context(void)
 {
     clkdm_for_each(_clkdm_save_context, NULL);
 }
 
 /**
  * clkdm_restore_context - Restores the context for each registered clkdm
  *
  * Restore the context for each registered clockdomain.
  */
 void clkdm_restore_context(void)
 {
     clkdm_for_each(_clkdm_restore_context, NULL);
 }

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