1 files changed, 607 insertions, 181 deletions

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index dd285f001467..b87ad66f083e 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -1,10 +1,11 @@
 /*
- * OMAP2/3 clockdomain framework functions
+ * OMAP2/3/4 clockdomain framework functions
  *
- * Copyright (C) 2008 Texas Instruments, Inc.
- * Copyright (C) 2008-2009 Nokia Corporation
+ * 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
@@ -26,43 +27,124 @@
 
 #include <linux/bitops.h>
 
-#include <plat/clock.h>
-
 #include "prm.h"
 #include "prm-regbits-24xx.h"
 #include "cm.h"
 
+#include <plat/clock.h>
 #include <plat/powerdomain.h>
 #include <plat/clockdomain.h>
+#include <plat/prcm.h>
 
 /* clkdm_list contains all registered struct clockdomains */
 static LIST_HEAD(clkdm_list);
 
-/* clkdm_mutex protects clkdm_list add and del ops */
-static DEFINE_MUTEX(clkdm_mutex);
-
-/* array of powerdomain deps to be added/removed when clkdm in hwsup mode */
-static struct clkdm_pwrdm_autodep *autodeps;
+/* array of clockdomain deps to be added/removed when clkdm in hwsup mode */
+static struct clkdm_autodep *autodeps;
 
 
 /* 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 pwrdm names to pwrdm pointers; store
- * @autodep: struct clkdm_pwrdm_autodep * to resolve
+ * _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store
+ * @autodep: struct clkdm_autodep * to resolve
  *
- * Resolve autodep powerdomain names to powerdomain pointers via
- * pwrdm_lookup() and store the pointers in the autodep structure.  An
- * "autodep" is a powerdomain sleep/wakeup dependency that is
+ * 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.
  */
-static void _autodep_lookup(struct clkdm_pwrdm_autodep *autodep)
+static void _autodep_lookup(struct clkdm_autodep *autodep)
 {
-        struct powerdomain *pwrdm;
+        struct clockdomain *clkdm;
 
         if (!autodep)
                 return;
@@ -70,13 +152,13 @@ static void _autodep_lookup(struct clkdm_pwrdm_autodep *autodep)
         if (!omap_chip_is(autodep->omap_chip))
                 return;
 
-        pwrdm = pwrdm_lookup(autodep->pwrdm.name);
-        if (!pwrdm) {
-                pr_err("clockdomain: autodeps: powerdomain %s does not exist\n",
-                         autodep->pwrdm.name);
-                pwrdm = ERR_PTR(-ENOENT);
+        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->pwrdm.ptr = pwrdm;
+        autodep->clkdm.ptr = clkdm;
 }
 
 /*
@@ -89,21 +171,24 @@ static void _autodep_lookup(struct clkdm_pwrdm_autodep *autodep)
  */
 static void _clkdm_add_autodeps(struct clockdomain *clkdm)
 {
-        struct clkdm_pwrdm_autodep *autodep;
+        struct clkdm_autodep *autodep;
 
-        for (autodep = autodeps; autodep->pwrdm.ptr; autodep++) {
-                if (IS_ERR(autodep->pwrdm.ptr))
+        if (!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 "
-                         "pwrdm %s\n", autodep->pwrdm.ptr->name,
-                         clkdm->pwrdm.ptr->name);
+                         "clkdm %s\n", autodep->clkdm.ptr->name,
+                         clkdm->name);
 
-                pwrdm_add_sleepdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
-                pwrdm_add_wkdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
+                clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
+                clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
         }
 }
 
@@ -117,21 +202,24 @@ static void _clkdm_add_autodeps(struct clockdomain *clkdm)
  */
 static void _clkdm_del_autodeps(struct clockdomain *clkdm)
 {
-        struct clkdm_pwrdm_autodep *autodep;
+        struct clkdm_autodep *autodep;
+
+        if (!autodeps)
+                return;
 
-        for (autodep = autodeps; autodep->pwrdm.ptr; autodep++) {
-                if (IS_ERR(autodep->pwrdm.ptr))
+        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 "
-                         "pwrdm %s\n", autodep->pwrdm.ptr->name,
-                         clkdm->pwrdm.ptr->name);
+                         "clkdm %s\n", autodep->clkdm.ptr->name,
+                         clkdm->name);
 
-                pwrdm_del_sleepdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
-                pwrdm_del_wkdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
+                clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
+                clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
         }
 }
 
@@ -145,152 +233,167 @@ static void _clkdm_del_autodeps(struct clockdomain *clkdm)
  */
 static void _omap2_clkdm_set_hwsup(struct clockdomain *clkdm, int enable)
 {
-        u32 v;
+        u32 bits, v;
 
         if (cpu_is_omap24xx()) {
                 if (enable)
-                        v = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
+                        bits = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
                 else
-                        v = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
-        } else if (cpu_is_omap34xx()) {
+                        bits = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
+        } else if (cpu_is_omap34xx() | cpu_is_omap44xx()) {
                 if (enable)
-                        v = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
+                        bits = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
                 else
-                        v = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
+                        bits = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
         } else {
                 BUG();
         }
 
-        cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
-                            v << __ffs(clkdm->clktrctrl_mask),
-                            clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
-}
-
-static struct clockdomain *_clkdm_lookup(const char *name)
-{
-        struct clockdomain *clkdm, *temp_clkdm;
-
-        if (!name)
-                return NULL;
-
-        clkdm = NULL;
+        bits = bits << __ffs(clkdm->clktrctrl_mask);
 
-        list_for_each_entry(temp_clkdm, &clkdm_list, node) {
-                if (!strcmp(name, temp_clkdm->name)) {
-                        clkdm = temp_clkdm;
-                        break;
-                }
-        }
+        v = __raw_readl(clkdm->clkstctrl_reg);
+        v &= ~(clkdm->clktrctrl_mask);
+        v |= bits;
+        __raw_writel(v, clkdm->clkstctrl_reg);
 
-        return clkdm;
 }
 
-
-/* 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
+ * _init_wkdep_usecount - initialize wkdep usecounts to match hardware
+ * @clkdm: clockdomain to initialize wkdep usecounts
  *
- * Set up internal state.  If a pointer to an array of clockdomains
- * 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-powerdomain autodependencies was
- * provided, register those.  No return value.
+ * Initialize the wakeup dependency usecount variables for clockdomain @clkdm.
+ * If a wakeup dependency is present in the hardware, the usecount will be
+ * set to 1; otherwise, it will be set to 0.  Software should clear all
+ * software wakeup dependencies prior to calling this function if it wishes
+ * to ensure that all usecounts start at 0.  No return value.
  */
-void clkdm_init(struct clockdomain **clkdms,
-                struct clkdm_pwrdm_autodep *init_autodeps)
+static void _init_wkdep_usecount(struct clockdomain *clkdm)
 {
-        struct clockdomain **c = NULL;
-        struct clkdm_pwrdm_autodep *autodep = NULL;
+        u32 v;
+        struct clkdm_dep *cd;
 
-        if (clkdms)
-                for (c = clkdms; *c; c++)
-                        clkdm_register(*c);
+        if (!clkdm->wkdep_srcs)
+                return;
 
-        autodeps = init_autodeps;
-        if (autodeps)
-                for (autodep = autodeps; autodep->pwrdm.ptr; autodep++)
-                        _autodep_lookup(autodep);
+        for (cd = clkdm->wkdep_srcs; 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) {
+                        WARN(!cd->clkdm, "clockdomain: %s: wkdep clkdm %s not "
+                             "found\n", clkdm->name, cd->clkdm_name);
+                        continue;
+                }
+
+                v = prm_read_mod_bits_shift(clkdm->pwrdm.ptr->prcm_offs,
+                                            PM_WKDEP,
+                                            (1 << cd->clkdm->dep_bit));
+
+                if (v)
+                        pr_debug("clockdomain: %s: wakeup dependency already "
+                                 "set to wake up when %s wakes\n",
+                                 clkdm->name, cd->clkdm->name);
+
+                atomic_set(&cd->wkdep_usecount, (v) ? 1 : 0);
+        }
 }
 
 /**
- * clkdm_register - register a clockdomain
- * @clkdm: struct clockdomain * to register
+ * _init_sleepdep_usecount - initialize sleepdep usecounts to match hardware
+ * @clkdm: clockdomain to initialize sleepdep usecounts
  *
- * 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.
+ * Initialize the sleep dependency usecount variables for clockdomain @clkdm.
+ * If a sleep dependency is present in the hardware, the usecount will be
+ * set to 1; otherwise, it will be set to 0.  Software should clear all
+ * software sleep dependencies prior to calling this function if it wishes
+ * to ensure that all usecounts start at 0.  No return value.
  */
-int clkdm_register(struct clockdomain *clkdm)
+static void _init_sleepdep_usecount(struct clockdomain *clkdm)
 {
-        int ret = -EINVAL;
-        struct powerdomain *pwrdm;
+        u32 v;
+        struct clkdm_dep *cd;
 
-        if (!clkdm || !clkdm->name)
-                return -EINVAL;
+        if (!cpu_is_omap34xx())
+                return;
 
-        if (!omap_chip_is(clkdm->omap_chip))
-                return -EINVAL;
+        if (!clkdm->sleepdep_srcs)
+                return;
 
-        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;
+        for (cd = clkdm->sleepdep_srcs; cd->clkdm_name; cd++) {
+                if (!omap_chip_is(cd->omap_chip))
+                        continue;
 
-        mutex_lock(&clkdm_mutex);
-        /* Verify that the clockdomain is not already registered */
-        if (_clkdm_lookup(clkdm->name)) {
-                ret = -EEXIST;
-                goto cr_unlock;
-        }
+                if (!cd->clkdm && cd->clkdm_name)
+                        cd->clkdm = _clkdm_lookup(cd->clkdm_name);
 
-        list_add(&clkdm->node, &clkdm_list);
+                if (!cd->clkdm) {
+                        WARN(!cd->clkdm, "clockdomain: %s: sleepdep clkdm %s "
+                             "not found\n", clkdm->name, cd->clkdm_name);
+                        continue;
+                }
 
-        pwrdm_add_clkdm(pwrdm, clkdm);
+                v = prm_read_mod_bits_shift(clkdm->pwrdm.ptr->prcm_offs,
+                                            OMAP3430_CM_SLEEPDEP,
+                                            (1 << cd->clkdm->dep_bit));
 
-        pr_debug("clockdomain: registered %s\n", clkdm->name);
-        ret = 0;
+                if (v)
+                        pr_debug("clockdomain: %s: sleep dependency already "
+                                 "set to prevent from idling until %s "
+                                 "idles\n", clkdm->name, cd->clkdm->name);
 
-cr_unlock:
-        mutex_unlock(&clkdm_mutex);
+                atomic_set(&cd->sleepdep_usecount, (v) ? 1 : 0);
+        }
+};
 
-        return ret;
-}
+/* Public functions */
 
 /**
- * clkdm_unregister - unregister a clockdomain
- * @clkdm: struct clockdomain * to unregister
+ * 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
  *
- * Removes a clockdomain from the internal clockdomain list.  Returns
- * -EINVAL if clkdm argument is NULL.
+ * 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.
  */
-int clkdm_unregister(struct clockdomain *clkdm)
+void clkdm_init(struct clockdomain **clkdms,
+                struct clkdm_autodep *init_autodeps)
 {
-        if (!clkdm)
-                return -EINVAL;
-
-        pwrdm_del_clkdm(clkdm->pwrdm.ptr, clkdm);
+        struct clockdomain **c = NULL;
+        struct clockdomain *clkdm;
+        struct clkdm_autodep *autodep = NULL;
 
-        mutex_lock(&clkdm_mutex);
-        list_del(&clkdm->node);
-        mutex_unlock(&clkdm_mutex);
+        if (clkdms)
+                for (c = clkdms; *c; c++)
+                        _clkdm_register(*c);
 
-        pr_debug("clockdomain: unregistered %s\n", clkdm->name);
+        autodeps = init_autodeps;
+        if (autodeps)
+                for (autodep = autodeps; autodep->clkdm.ptr; autodep++)
+                        _autodep_lookup(autodep);
 
-        return 0;
+        /*
+         * Ensure that the *dep_usecount registers reflect the current
+         * state of the PRCM.
+         */
+        list_for_each_entry(clkdm, &clkdm_list, node) {
+                _init_wkdep_usecount(clkdm);
+                _init_sleepdep_usecount(clkdm);
+        }
 }
 
 /**
  * clkdm_lookup - look up a clockdomain by name, return a pointer
  * @name: name of clockdomain
  *
- * Find a registered clockdomain by its name.  Returns a pointer to the
- * struct clockdomain if found, or NULL otherwise.
+ * 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)
 {
@@ -301,14 +404,12 @@ struct clockdomain *clkdm_lookup(const char *name)
 
         clkdm = NULL;
 
-        mutex_lock(&clkdm_mutex);
         list_for_each_entry(temp_clkdm, &clkdm_list, node) {
                 if (!strcmp(name, temp_clkdm->name)) {
                         clkdm = temp_clkdm;
                         break;
                 }
         }
-        mutex_unlock(&clkdm_mutex);
 
         return clkdm;
 }
@@ -317,8 +418,8 @@ struct clockdomain *clkdm_lookup(const char *name)
  * clkdm_for_each - call function on each registered clockdomain
  * @fn: callback function *
  *
- * Call the supplied function for each registered clockdomain.
- * The callback function can return anything but 0 to bail
+ * 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
@@ -336,13 +437,11 @@ int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
         if (!fn)
                 return -EINVAL;
 
-        mutex_lock(&clkdm_mutex);
         list_for_each_entry(clkdm, &clkdm_list, node) {
                 ret = (*fn)(clkdm, user);
                 if (ret)
                         break;
         }
-        mutex_unlock(&clkdm_mutex);
 
         return ret;
 }
@@ -353,7 +452,7 @@ int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
  * @clkdm: struct clockdomain *
  *
  * Return a pointer to the struct powerdomain that the specified clockdomain
- * 'clkdm' exists in, or returns NULL if clkdm argument is NULL.
+ * @clkdm exists in, or returns NULL if @clkdm is NULL.
  */
 struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
 {
@@ -367,11 +466,309 @@ struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
 /* 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;
+
+        if (!clkdm1 || !clkdm2)
+                return -EINVAL;
+
+        cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+        if (IS_ERR(cd)) {
+                pr_debug("clockdomain: hardware cannot set/clear wake up of "
+                         "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
+                return PTR_ERR(cd);
+        }
+
+        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);
+
+                prm_set_mod_reg_bits((1 << clkdm2->dep_bit),
+                                     clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
+        }
+
+        return 0;
+}
+
+/**
+ * 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;
+
+        if (!clkdm1 || !clkdm2)
+                return -EINVAL;
+
+        cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+        if (IS_ERR(cd)) {
+                pr_debug("clockdomain: hardware cannot set/clear wake up of "
+                         "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
+                return PTR_ERR(cd);
+        }
+
+        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);
+
+                prm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
+                                       clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
+        }
+
+        return 0;
+}
+
+/**
+ * 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;
+
+        if (!clkdm1 || !clkdm2)
+                return -EINVAL;
+
+        cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+        if (IS_ERR(cd)) {
+                pr_debug("clockdomain: hardware cannot set/clear wake up of "
+                         "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
+                return PTR_ERR(cd);
+        }
+
+        /* XXX It's faster to return the atomic wkdep_usecount */
+        return prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP,
+                                       (1 << clkdm2->dep_bit));
+}
+
+/**
+ * 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)
+{
+        struct clkdm_dep *cd;
+        u32 mask = 0;
+
+        if (!clkdm)
+                return -EINVAL;
+
+        for (cd = clkdm->wkdep_srcs; cd && cd->clkdm_name; cd++) {
+                if (!omap_chip_is(cd->omap_chip))
+                        continue;
+
+                /* PRM accesses are slow, so minimize them */
+                mask |= 1 << cd->clkdm->dep_bit;
+                atomic_set(&cd->wkdep_usecount, 0);
+        }
+
+        prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs, PM_WKDEP);
+
+        return 0;
+}
+
+/**
+ * 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;
+
+        if (!cpu_is_omap34xx())
+                return -EINVAL;
+
+        if (!clkdm1 || !clkdm2)
+                return -EINVAL;
+
+        cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
+        if (IS_ERR(cd)) {
+                pr_debug("clockdomain: hardware cannot set/clear sleep "
+                         "dependency affecting %s from %s\n", clkdm1->name,
+                         clkdm2->name);
+                return PTR_ERR(cd);
+        }
+
+        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);
+
+                cm_set_mod_reg_bits((1 << clkdm2->dep_bit),
+                                    clkdm1->pwrdm.ptr->prcm_offs,
+                                    OMAP3430_CM_SLEEPDEP);
+        }
+
+        return 0;
+}
+
+/**
+ * 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;
+
+        if (!cpu_is_omap34xx())
+                return -EINVAL;
+
+        if (!clkdm1 || !clkdm2)
+                return -EINVAL;
+
+        cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
+        if (IS_ERR(cd)) {
+                pr_debug("clockdomain: hardware cannot set/clear sleep "
+                         "dependency affecting %s from %s\n", clkdm1->name,
+                         clkdm2->name);
+                return PTR_ERR(cd);
+        }
+
+        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);
+
+                cm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
+                                      clkdm1->pwrdm.ptr->prcm_offs,
+                                      OMAP3430_CM_SLEEPDEP);
+        }
+
+        return 0;
+}
+
+/**
+ * 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;
+
+        if (!cpu_is_omap34xx())
+                return -EINVAL;
+
+        if (!clkdm1 || !clkdm2)
+                return -EINVAL;
+
+        cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
+        if (IS_ERR(cd)) {
+                pr_debug("clockdomain: hardware cannot set/clear sleep "
+                         "dependency affecting %s from %s\n", clkdm1->name,
+                         clkdm2->name);
+                return PTR_ERR(cd);
+        }
+
+        /* XXX It's faster to return the atomic sleepdep_usecount */
+        return prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs,
+                                       OMAP3430_CM_SLEEPDEP,
+                                       (1 << clkdm2->dep_bit));
+}
+
+/**
+ * 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)
+{
+        struct clkdm_dep *cd;
+        u32 mask = 0;
+
+        if (!cpu_is_omap34xx())
+                return -EINVAL;
+
+        if (!clkdm)
+                return -EINVAL;
+
+        for (cd = clkdm->sleepdep_srcs; cd && cd->clkdm_name; cd++) {
+                if (!omap_chip_is(cd->omap_chip))
+                        continue;
+
+                /* PRM accesses are slow, so minimize them */
+                mask |= 1 << cd->clkdm->dep_bit;
+                atomic_set(&cd->sleepdep_usecount, 0);
+        }
+
+        prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs,
+                               OMAP3430_CM_SLEEPDEP);
+
+        return 0;
+}
+
+/**
  * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode
- * @clk: struct clk * of a clockdomain
+ * @clkdm: struct clkdm * of a clockdomain
  *
- * Return the clockdomain's current state transition mode from the
- * corresponding domain CM_CLKSTCTRL register.  Returns -EINVAL if clk
+ * Return the clockdomain @clkdm current state transition mode from the
+ * corresponding domain CM_CLKSTCTRL register.  Returns -EINVAL if @clkdm
  * is NULL or the current mode upon success.
  */
 static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
@@ -381,7 +778,7 @@ static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
         if (!clkdm)
                 return -EINVAL;
 
-        v = cm_read_mod_reg(clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
+        v = __raw_readl(clkdm->clkstctrl_reg);
         v &= clkdm->clktrctrl_mask;
         v >>= __ffs(clkdm->clktrctrl_mask);
 
@@ -393,7 +790,7 @@ static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
  * @clkdm: struct clockdomain *
  *
  * Instruct the CM to force a sleep transition on the specified
- * clockdomain 'clkdm'.  Returns -EINVAL if clk is NULL or if
+ * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if
  * clockdomain does not support software-initiated sleep; 0 upon
  * success.
  */
@@ -413,15 +810,17 @@ int omap2_clkdm_sleep(struct clockdomain *clkdm)
         if (cpu_is_omap24xx()) {
 
                 cm_set_mod_reg_bits(OMAP24XX_FORCESTATE,
-                                    clkdm->pwrdm.ptr->prcm_offs, PM_PWSTCTRL);
+                            clkdm->pwrdm.ptr->prcm_offs, OMAP2_PM_PWSTCTRL);
 
-        } else if (cpu_is_omap34xx()) {
+        } else if (cpu_is_omap34xx() | cpu_is_omap44xx()) {
 
-                u32 v = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP <<
+                u32 bits = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP <<
                          __ffs(clkdm->clktrctrl_mask));
 
-                cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
-                                    clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
+                u32 v = __raw_readl(clkdm->clkstctrl_reg);
+                v &= ~(clkdm->clktrctrl_mask);
+                v |= bits;
+                __raw_writel(v, clkdm->clkstctrl_reg);
 
         } else {
                 BUG();
@@ -435,7 +834,7 @@ int omap2_clkdm_sleep(struct clockdomain *clkdm)
  * @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 @clkdm.  Returns -EINVAL if @clkdm is NULL or if the
  * clockdomain does not support software-controlled wakeup; 0 upon
  * success.
  */
@@ -455,15 +854,17 @@ int omap2_clkdm_wakeup(struct clockdomain *clkdm)
         if (cpu_is_omap24xx()) {
 
                 cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE,
-                                      clkdm->pwrdm.ptr->prcm_offs, PM_PWSTCTRL);
+                              clkdm->pwrdm.ptr->prcm_offs, OMAP2_PM_PWSTCTRL);
 
-        } else if (cpu_is_omap34xx()) {
+        } else if (cpu_is_omap34xx() | cpu_is_omap44xx()) {
 
-                u32 v = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP <<
+                u32 bits = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP <<
                          __ffs(clkdm->clktrctrl_mask));
 
-                cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
-                                    clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
+                u32 v = __raw_readl(clkdm->clkstctrl_reg);
+                v &= ~(clkdm->clktrctrl_mask);
+                v |= bits;
+                __raw_writel(v, clkdm->clkstctrl_reg);
 
         } else {
                 BUG();
@@ -476,7 +877,7 @@ int omap2_clkdm_wakeup(struct clockdomain *clkdm)
  * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
  * @clkdm: struct clockdomain *
  *
- * Allow the hardware to automatically switch the clockdomain into
+ * 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
@@ -496,8 +897,17 @@ void omap2_clkdm_allow_idle(struct clockdomain *clkdm)
         pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
                  clkdm->name);
 
-        if (atomic_read(&clkdm->usecount) > 0)
-                _clkdm_add_autodeps(clkdm);
+        /*
+         * XXX This should be removed once TI adds wakeup/sleep
+         * dependency code and data for OMAP4.
+         */
+        if (cpu_is_omap44xx()) {
+                WARN_ONCE(1, "clockdomain: OMAP4 wakeup/sleep dependency "
+                          "support is not yet implemented\n");
+        } else {
+                if (atomic_read(&clkdm->usecount) > 0)
+                        _clkdm_add_autodeps(clkdm);
+        }
 
         _omap2_clkdm_set_hwsup(clkdm, 1);
 
@@ -509,8 +919,8 @@ void omap2_clkdm_allow_idle(struct clockdomain *clkdm)
  * @clkdm: struct clockdomain *
  *
  * Prevent the hardware from automatically switching the clockdomain
- * into inactive or idle states.  If the clockdomain has downstream
- * clocks enabled in the clock framework, wkdep/sleepdep
+ * @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 omap2_clkdm_deny_idle(struct clockdomain *clkdm)
@@ -529,8 +939,17 @@ void omap2_clkdm_deny_idle(struct clockdomain *clkdm)
 
         _omap2_clkdm_set_hwsup(clkdm, 0);
 
-        if (atomic_read(&clkdm->usecount) > 0)
-                _clkdm_del_autodeps(clkdm);
+        /*
+         * XXX This should be removed once TI adds wakeup/sleep
+         * dependency code and data for OMAP4.
+         */
+        if (cpu_is_omap44xx()) {
+                WARN_ONCE(1, "clockdomain: OMAP4 wakeup/sleep dependency "
+                          "support is not yet implemented\n");
+        } else {
+                if (atomic_read(&clkdm->usecount) > 0)
+                        _clkdm_del_autodeps(clkdm);
+        }
 }
 
 
@@ -541,14 +960,14 @@ void omap2_clkdm_deny_idle(struct clockdomain *clkdm)
  * @clkdm: struct clockdomain *
  * @clk: struct clk * of the enabled downstream clock
  *
- * Increment the usecount of this clockdomain 'clkdm' and ensure that
- * it is awake.  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.
+ * 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 omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
 {
@@ -559,7 +978,7 @@ int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
          * downstream clocks for debugging purposes?
          */
 
-        if (!clkdm || !clk || !clkdm->clktrctrl_mask)
+        if (!clkdm || !clk)
                 return -EINVAL;
 
         if (atomic_inc_return(&clkdm->usecount) > 1)
@@ -570,6 +989,9 @@ int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
         pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
                  clk->name);
 
+        if (!clkdm->clkstctrl_reg)
+                return 0;
+
         v = omap2_clkdm_clktrctrl_read(clkdm);
 
         if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
@@ -593,13 +1015,14 @@ int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
  * @clkdm: struct clockdomain *
  * @clk: struct clk * of the disabled downstream clock
  *
- * Decrement the usecount of this clockdomain 'clkdm'. Intended to be
- * called by clk_disable() code.  If the usecount goes to 0, put the
- * clockdomain to sleep (software-supervised mode) or remove the
- * clkdm-pwrdm 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.
+ * 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 omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
 {
@@ -610,7 +1033,7 @@ int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
          * downstream clocks for debugging purposes?
          */
 
-        if (!clkdm || !clk || !clkdm->clktrctrl_mask)
+        if (!clkdm || !clk)
                 return -EINVAL;
 
 #ifdef DEBUG
@@ -628,6 +1051,9 @@ int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
         pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
                  clk->name);
 
+        if (!clkdm->clkstctrl_reg)
+                return 0;
+
         v = omap2_clkdm_clktrctrl_read(clkdm);
 
         if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||