Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / arch / arm / mach-omap2 / powerdomain.c
diff --git a/kernel/arch/arm/mach-omap2/powerdomain.c b/kernel/arch/arm/mach-omap2/powerdomain.c
new file mode 100644 (file)
index 0000000..78af6d8
--- /dev/null
@@ -0,0 +1,1208 @@
+/*
+ * OMAP powerdomain control
+ *
+ * Copyright (C) 2007-2008, 2011 Texas Instruments, Inc.
+ * Copyright (C) 2007-2011 Nokia Corporation
+ *
+ * Written by Paul Walmsley
+ * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
+ * State counting code by Tero Kristo <tero.kristo@nokia.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/types.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/spinlock.h>
+#include <trace/events/power.h>
+
+#include "cm2xxx_3xxx.h"
+#include "prcm44xx.h"
+#include "cm44xx.h"
+#include "prm2xxx_3xxx.h"
+#include "prm44xx.h"
+
+#include <asm/cpu.h>
+
+#include "powerdomain.h"
+#include "clockdomain.h"
+#include "voltage.h"
+
+#include "soc.h"
+#include "pm.h"
+
+#define PWRDM_TRACE_STATES_FLAG        (1<<31)
+
+enum {
+       PWRDM_STATE_NOW = 0,
+       PWRDM_STATE_PREV,
+};
+
+/*
+ * Types of sleep_switch used internally in omap_set_pwrdm_state()
+ * and its associated static functions
+ *
+ * XXX Better documentation is needed here
+ */
+#define ALREADYACTIVE_SWITCH           0
+#define FORCEWAKEUP_SWITCH             1
+#define LOWPOWERSTATE_SWITCH           2
+
+/* pwrdm_list contains all registered struct powerdomains */
+static LIST_HEAD(pwrdm_list);
+
+static struct pwrdm_ops *arch_pwrdm;
+
+/* Private functions */
+
+static struct powerdomain *_pwrdm_lookup(const char *name)
+{
+       struct powerdomain *pwrdm, *temp_pwrdm;
+
+       pwrdm = NULL;
+
+       list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
+               if (!strcmp(name, temp_pwrdm->name)) {
+                       pwrdm = temp_pwrdm;
+                       break;
+               }
+       }
+
+       return pwrdm;
+}
+
+/**
+ * _pwrdm_register - register a powerdomain
+ * @pwrdm: struct powerdomain * to register
+ *
+ * Adds a powerdomain to the internal powerdomain list.  Returns
+ * -EINVAL if given a null pointer, -EEXIST if a powerdomain is
+ * already registered by the provided name, or 0 upon success.
+ */
+static int _pwrdm_register(struct powerdomain *pwrdm)
+{
+       int i;
+       struct voltagedomain *voltdm;
+
+       if (!pwrdm || !pwrdm->name)
+               return -EINVAL;
+
+       if (cpu_is_omap44xx() &&
+           pwrdm->prcm_partition == OMAP4430_INVALID_PRCM_PARTITION) {
+               pr_err("powerdomain: %s: missing OMAP4 PRCM partition ID\n",
+                      pwrdm->name);
+               return -EINVAL;
+       }
+
+       if (_pwrdm_lookup(pwrdm->name))
+               return -EEXIST;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_has_voltdm)
+               if (!arch_pwrdm->pwrdm_has_voltdm())
+                       goto skip_voltdm;
+
+       voltdm = voltdm_lookup(pwrdm->voltdm.name);
+       if (!voltdm) {
+               pr_err("powerdomain: %s: voltagedomain %s does not exist\n",
+                      pwrdm->name, pwrdm->voltdm.name);
+               return -EINVAL;
+       }
+       pwrdm->voltdm.ptr = voltdm;
+       INIT_LIST_HEAD(&pwrdm->voltdm_node);
+skip_voltdm:
+       spin_lock_init(&pwrdm->_lock);
+
+       list_add(&pwrdm->node, &pwrdm_list);
+
+       /* Initialize the powerdomain's state counter */
+       for (i = 0; i < PWRDM_MAX_PWRSTS; i++)
+               pwrdm->state_counter[i] = 0;
+
+       pwrdm->ret_logic_off_counter = 0;
+       for (i = 0; i < pwrdm->banks; i++)
+               pwrdm->ret_mem_off_counter[i] = 0;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_wait_transition)
+               arch_pwrdm->pwrdm_wait_transition(pwrdm);
+       pwrdm->state = pwrdm_read_pwrst(pwrdm);
+       pwrdm->state_counter[pwrdm->state] = 1;
+
+       pr_debug("powerdomain: registered %s\n", pwrdm->name);
+
+       return 0;
+}
+
+static void _update_logic_membank_counters(struct powerdomain *pwrdm)
+{
+       int i;
+       u8 prev_logic_pwrst, prev_mem_pwrst;
+
+       prev_logic_pwrst = pwrdm_read_prev_logic_pwrst(pwrdm);
+       if ((pwrdm->pwrsts_logic_ret == PWRSTS_OFF_RET) &&
+           (prev_logic_pwrst == PWRDM_POWER_OFF))
+               pwrdm->ret_logic_off_counter++;
+
+       for (i = 0; i < pwrdm->banks; i++) {
+               prev_mem_pwrst = pwrdm_read_prev_mem_pwrst(pwrdm, i);
+
+               if ((pwrdm->pwrsts_mem_ret[i] == PWRSTS_OFF_RET) &&
+                   (prev_mem_pwrst == PWRDM_POWER_OFF))
+                       pwrdm->ret_mem_off_counter[i]++;
+       }
+}
+
+static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag)
+{
+
+       int prev, next, state, trace_state = 0;
+
+       if (pwrdm == NULL)
+               return -EINVAL;
+
+       state = pwrdm_read_pwrst(pwrdm);
+
+       switch (flag) {
+       case PWRDM_STATE_NOW:
+               prev = pwrdm->state;
+               break;
+       case PWRDM_STATE_PREV:
+               prev = pwrdm_read_prev_pwrst(pwrdm);
+               if (pwrdm->state != prev)
+                       pwrdm->state_counter[prev]++;
+               if (prev == PWRDM_POWER_RET)
+                       _update_logic_membank_counters(pwrdm);
+               /*
+                * If the power domain did not hit the desired state,
+                * generate a trace event with both the desired and hit states
+                */
+               next = pwrdm_read_next_pwrst(pwrdm);
+               if (next != prev) {
+                       trace_state = (PWRDM_TRACE_STATES_FLAG |
+                                      ((next & OMAP_POWERSTATE_MASK) << 8) |
+                                      ((prev & OMAP_POWERSTATE_MASK) << 0));
+                       trace_power_domain_target(pwrdm->name, trace_state,
+                                                 smp_processor_id());
+               }
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       if (state != prev)
+               pwrdm->state_counter[state]++;
+
+       pm_dbg_update_time(pwrdm, prev);
+
+       pwrdm->state = state;
+
+       return 0;
+}
+
+static int _pwrdm_pre_transition_cb(struct powerdomain *pwrdm, void *unused)
+{
+       pwrdm_clear_all_prev_pwrst(pwrdm);
+       _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);
+       return 0;
+}
+
+static int _pwrdm_post_transition_cb(struct powerdomain *pwrdm, void *unused)
+{
+       _pwrdm_state_switch(pwrdm, PWRDM_STATE_PREV);
+       return 0;
+}
+
+/**
+ * _pwrdm_save_clkdm_state_and_activate - prepare for power state change
+ * @pwrdm: struct powerdomain * to operate on
+ * @curr_pwrst: current power state of @pwrdm
+ * @pwrst: power state to switch to
+ * @hwsup: ptr to a bool to return whether the clkdm is hardware-supervised
+ *
+ * Determine whether the powerdomain needs to be turned on before
+ * attempting to switch power states.  Called by
+ * omap_set_pwrdm_state().  NOTE that if the powerdomain contains
+ * multiple clockdomains, this code assumes that the first clockdomain
+ * supports software-supervised wakeup mode - potentially a problem.
+ * Returns the power state switch mode currently in use (see the
+ * "Types of sleep_switch" comment above).
+ */
+static u8 _pwrdm_save_clkdm_state_and_activate(struct powerdomain *pwrdm,
+                                              u8 curr_pwrst, u8 pwrst,
+                                              bool *hwsup)
+{
+       u8 sleep_switch;
+
+       if (curr_pwrst < PWRDM_POWER_ON) {
+               if (curr_pwrst > pwrst &&
+                   pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
+                   arch_pwrdm->pwrdm_set_lowpwrstchange) {
+                       sleep_switch = LOWPOWERSTATE_SWITCH;
+               } else {
+                       *hwsup = clkdm_in_hwsup(pwrdm->pwrdm_clkdms[0]);
+                       clkdm_wakeup_nolock(pwrdm->pwrdm_clkdms[0]);
+                       sleep_switch = FORCEWAKEUP_SWITCH;
+               }
+       } else {
+               sleep_switch = ALREADYACTIVE_SWITCH;
+       }
+
+       return sleep_switch;
+}
+
+/**
+ * _pwrdm_restore_clkdm_state - restore the clkdm hwsup state after pwrst change
+ * @pwrdm: struct powerdomain * to operate on
+ * @sleep_switch: return value from _pwrdm_save_clkdm_state_and_activate()
+ * @hwsup: should @pwrdm's first clockdomain be set to hardware-supervised mode?
+ *
+ * Restore the clockdomain state perturbed by
+ * _pwrdm_save_clkdm_state_and_activate(), and call the power state
+ * bookkeeping code.  Called by omap_set_pwrdm_state().  NOTE that if
+ * the powerdomain contains multiple clockdomains, this assumes that
+ * the first associated clockdomain supports either
+ * hardware-supervised idle control in the register, or
+ * software-supervised sleep.  No return value.
+ */
+static void _pwrdm_restore_clkdm_state(struct powerdomain *pwrdm,
+                                      u8 sleep_switch, bool hwsup)
+{
+       switch (sleep_switch) {
+       case FORCEWAKEUP_SWITCH:
+               if (hwsup)
+                       clkdm_allow_idle_nolock(pwrdm->pwrdm_clkdms[0]);
+               else
+                       clkdm_sleep_nolock(pwrdm->pwrdm_clkdms[0]);
+               break;
+       case LOWPOWERSTATE_SWITCH:
+               if (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
+                   arch_pwrdm->pwrdm_set_lowpwrstchange)
+                       arch_pwrdm->pwrdm_set_lowpwrstchange(pwrdm);
+               pwrdm_state_switch_nolock(pwrdm);
+               break;
+       }
+}
+
+/* Public functions */
+
+/**
+ * pwrdm_register_platform_funcs - register powerdomain implementation fns
+ * @po: func pointers for arch specific implementations
+ *
+ * Register the list of function pointers used to implement the
+ * powerdomain functions on different OMAP SoCs.  Should be called
+ * before any other pwrdm_register*() function.  Returns -EINVAL if
+ * @po is null, -EEXIST if platform functions have already been
+ * registered, or 0 upon success.
+ */
+int pwrdm_register_platform_funcs(struct pwrdm_ops *po)
+{
+       if (!po)
+               return -EINVAL;
+
+       if (arch_pwrdm)
+               return -EEXIST;
+
+       arch_pwrdm = po;
+
+       return 0;
+}
+
+/**
+ * pwrdm_register_pwrdms - register SoC powerdomains
+ * @ps: pointer to an array of struct powerdomain to register
+ *
+ * Register the powerdomains available on a particular OMAP SoC.  Must
+ * be called after pwrdm_register_platform_funcs().  May be called
+ * multiple times.  Returns -EACCES if called before
+ * pwrdm_register_platform_funcs(); -EINVAL if the argument @ps is
+ * null; or 0 upon success.
+ */
+int pwrdm_register_pwrdms(struct powerdomain **ps)
+{
+       struct powerdomain **p = NULL;
+
+       if (!arch_pwrdm)
+               return -EEXIST;
+
+       if (!ps)
+               return -EINVAL;
+
+       for (p = ps; *p; p++)
+               _pwrdm_register(*p);
+
+       return 0;
+}
+
+/**
+ * pwrdm_complete_init - set up the powerdomain layer
+ *
+ * Do whatever is necessary to initialize registered powerdomains and
+ * powerdomain code.  Currently, this programs the next power state
+ * for each powerdomain to ON.  This prevents powerdomains from
+ * unexpectedly losing context or entering high wakeup latency modes
+ * with non-power-management-enabled kernels.  Must be called after
+ * pwrdm_register_pwrdms().  Returns -EACCES if called before
+ * pwrdm_register_pwrdms(), or 0 upon success.
+ */
+int pwrdm_complete_init(void)
+{
+       struct powerdomain *temp_p;
+
+       if (list_empty(&pwrdm_list))
+               return -EACCES;
+
+       list_for_each_entry(temp_p, &pwrdm_list, node)
+               pwrdm_set_next_pwrst(temp_p, PWRDM_POWER_ON);
+
+       return 0;
+}
+
+/**
+ * pwrdm_lock - acquire a Linux spinlock on a powerdomain
+ * @pwrdm: struct powerdomain * to lock
+ *
+ * Acquire the powerdomain spinlock on @pwrdm.  No return value.
+ */
+void pwrdm_lock(struct powerdomain *pwrdm)
+       __acquires(&pwrdm->_lock)
+{
+       spin_lock_irqsave(&pwrdm->_lock, pwrdm->_lock_flags);
+}
+
+/**
+ * pwrdm_unlock - release a Linux spinlock on a powerdomain
+ * @pwrdm: struct powerdomain * to unlock
+ *
+ * Release the powerdomain spinlock on @pwrdm.  No return value.
+ */
+void pwrdm_unlock(struct powerdomain *pwrdm)
+       __releases(&pwrdm->_lock)
+{
+       spin_unlock_irqrestore(&pwrdm->_lock, pwrdm->_lock_flags);
+}
+
+/**
+ * pwrdm_lookup - look up a powerdomain by name, return a pointer
+ * @name: name of powerdomain
+ *
+ * Find a registered powerdomain by its name @name.  Returns a pointer
+ * to the struct powerdomain if found, or NULL otherwise.
+ */
+struct powerdomain *pwrdm_lookup(const char *name)
+{
+       struct powerdomain *pwrdm;
+
+       if (!name)
+               return NULL;
+
+       pwrdm = _pwrdm_lookup(name);
+
+       return pwrdm;
+}
+
+/**
+ * pwrdm_for_each - call function on each registered clockdomain
+ * @fn: callback function *
+ *
+ * Call the supplied function @fn for each registered powerdomain.
+ * The callback function @fn can return anything but 0 to bail out
+ * early from the iterator.  Returns the last return value of the
+ * callback function, which should be 0 for success or anything else
+ * to indicate failure; or -EINVAL if the function pointer is null.
+ */
+int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm, void *user),
+                  void *user)
+{
+       struct powerdomain *temp_pwrdm;
+       int ret = 0;
+
+       if (!fn)
+               return -EINVAL;
+
+       list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
+               ret = (*fn)(temp_pwrdm, user);
+               if (ret)
+                       break;
+       }
+
+       return ret;
+}
+
+/**
+ * pwrdm_add_clkdm - add a clockdomain to a powerdomain
+ * @pwrdm: struct powerdomain * to add the clockdomain to
+ * @clkdm: struct clockdomain * to associate with a powerdomain
+ *
+ * Associate the clockdomain @clkdm with a powerdomain @pwrdm.  This
+ * enables the use of pwrdm_for_each_clkdm().  Returns -EINVAL if
+ * presented with invalid pointers; -ENOMEM if memory could not be allocated;
+ * or 0 upon success.
+ */
+int pwrdm_add_clkdm(struct powerdomain *pwrdm, struct clockdomain *clkdm)
+{
+       int i;
+       int ret = -EINVAL;
+
+       if (!pwrdm || !clkdm)
+               return -EINVAL;
+
+       pr_debug("powerdomain: %s: associating clockdomain %s\n",
+                pwrdm->name, clkdm->name);
+
+       for (i = 0; i < PWRDM_MAX_CLKDMS; i++) {
+               if (!pwrdm->pwrdm_clkdms[i])
+                       break;
+#ifdef DEBUG
+               if (pwrdm->pwrdm_clkdms[i] == clkdm) {
+                       ret = -EINVAL;
+                       goto pac_exit;
+               }
+#endif
+       }
+
+       if (i == PWRDM_MAX_CLKDMS) {
+               pr_debug("powerdomain: %s: increase PWRDM_MAX_CLKDMS for clkdm %s\n",
+                        pwrdm->name, clkdm->name);
+               WARN_ON(1);
+               ret = -ENOMEM;
+               goto pac_exit;
+       }
+
+       pwrdm->pwrdm_clkdms[i] = clkdm;
+
+       ret = 0;
+
+pac_exit:
+       return ret;
+}
+
+/**
+ * pwrdm_get_mem_bank_count - get number of memory banks in this powerdomain
+ * @pwrdm: struct powerdomain *
+ *
+ * Return the number of controllable memory banks in powerdomain @pwrdm,
+ * starting with 1.  Returns -EINVAL if the powerdomain pointer is null.
+ */
+int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm)
+{
+       if (!pwrdm)
+               return -EINVAL;
+
+       return pwrdm->banks;
+}
+
+/**
+ * pwrdm_set_next_pwrst - set next powerdomain power state
+ * @pwrdm: struct powerdomain * to set
+ * @pwrst: one of the PWRDM_POWER_* macros
+ *
+ * Set the powerdomain @pwrdm's next power state to @pwrst.  The powerdomain
+ * may not enter this state immediately if the preconditions for this state
+ * have not been satisfied.  Returns -EINVAL if the powerdomain pointer is
+ * null or if the power state is invalid for the powerdomin, or returns 0
+ * upon success.
+ */
+int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (!(pwrdm->pwrsts & (1 << pwrst)))
+               return -EINVAL;
+
+       pr_debug("powerdomain: %s: setting next powerstate to %0x\n",
+                pwrdm->name, pwrst);
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) {
+               /* Trace the pwrdm desired target state */
+               trace_power_domain_target(pwrdm->name, pwrst,
+                                         smp_processor_id());
+               /* Program the pwrdm desired target state */
+               ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst);
+       }
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_next_pwrst - get next powerdomain power state
+ * @pwrdm: struct powerdomain * to get power state
+ *
+ * Return the powerdomain @pwrdm's next power state.  Returns -EINVAL
+ * if the powerdomain pointer is null or returns the next power state
+ * upon success.
+ */
+int pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_next_pwrst)
+               ret = arch_pwrdm->pwrdm_read_next_pwrst(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_pwrst - get current powerdomain power state
+ * @pwrdm: struct powerdomain * to get power state
+ *
+ * Return the powerdomain @pwrdm's current power state.        Returns -EINVAL
+ * if the powerdomain pointer is null or returns the current power state
+ * upon success. Note that if the power domain only supports the ON state
+ * then just return ON as the current state.
+ */
+int pwrdm_read_pwrst(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (pwrdm->pwrsts == PWRSTS_ON)
+               return PWRDM_POWER_ON;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_pwrst)
+               ret = arch_pwrdm->pwrdm_read_pwrst(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_prev_pwrst - get previous powerdomain power state
+ * @pwrdm: struct powerdomain * to get previous power state
+ *
+ * Return the powerdomain @pwrdm's previous power state.  Returns -EINVAL
+ * if the powerdomain pointer is null or returns the previous power state
+ * upon success.
+ */
+int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_pwrst)
+               ret = arch_pwrdm->pwrdm_read_prev_pwrst(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_set_logic_retst - set powerdomain logic power state upon retention
+ * @pwrdm: struct powerdomain * to set
+ * @pwrst: one of the PWRDM_POWER_* macros
+ *
+ * Set the next power state @pwrst that the logic portion of the
+ * powerdomain @pwrdm will enter when the powerdomain enters retention.
+ * This will be either RETENTION or OFF, if supported.  Returns
+ * -EINVAL if the powerdomain pointer is null or the target power
+ * state is not not supported, or returns 0 upon success.
+ */
+int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (!(pwrdm->pwrsts_logic_ret & (1 << pwrst)))
+               return -EINVAL;
+
+       pr_debug("powerdomain: %s: setting next logic powerstate to %0x\n",
+                pwrdm->name, pwrst);
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_set_logic_retst)
+               ret = arch_pwrdm->pwrdm_set_logic_retst(pwrdm, pwrst);
+
+       return ret;
+}
+
+/**
+ * pwrdm_set_mem_onst - set memory power state while powerdomain ON
+ * @pwrdm: struct powerdomain * to set
+ * @bank: memory bank number to set (0-3)
+ * @pwrst: one of the PWRDM_POWER_* macros
+ *
+ * Set the next power state @pwrst that memory bank @bank of the
+ * powerdomain @pwrdm will enter when the powerdomain enters the ON
+ * state.  @bank will be a number from 0 to 3, and represents different
+ * types of memory, depending on the powerdomain.  Returns -EINVAL if
+ * the powerdomain pointer is null or the target power state is not
+ * not supported for this memory bank, -EEXIST if the target memory
+ * bank does not exist or is not controllable, or returns 0 upon
+ * success.
+ */
+int pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (pwrdm->banks < (bank + 1))
+               return -EEXIST;
+
+       if (!(pwrdm->pwrsts_mem_on[bank] & (1 << pwrst)))
+               return -EINVAL;
+
+       pr_debug("powerdomain: %s: setting next memory powerstate for bank %0x while pwrdm-ON to %0x\n",
+                pwrdm->name, bank, pwrst);
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_set_mem_onst)
+               ret = arch_pwrdm->pwrdm_set_mem_onst(pwrdm, bank, pwrst);
+
+       return ret;
+}
+
+/**
+ * pwrdm_set_mem_retst - set memory power state while powerdomain in RET
+ * @pwrdm: struct powerdomain * to set
+ * @bank: memory bank number to set (0-3)
+ * @pwrst: one of the PWRDM_POWER_* macros
+ *
+ * Set the next power state @pwrst that memory bank @bank of the
+ * powerdomain @pwrdm will enter when the powerdomain enters the
+ * RETENTION state.  Bank will be a number from 0 to 3, and represents
+ * different types of memory, depending on the powerdomain.  @pwrst
+ * will be either RETENTION or OFF, if supported.  Returns -EINVAL if
+ * the powerdomain pointer is null or the target power state is not
+ * not supported for this memory bank, -EEXIST if the target memory
+ * bank does not exist or is not controllable, or returns 0 upon
+ * success.
+ */
+int pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (pwrdm->banks < (bank + 1))
+               return -EEXIST;
+
+       if (!(pwrdm->pwrsts_mem_ret[bank] & (1 << pwrst)))
+               return -EINVAL;
+
+       pr_debug("powerdomain: %s: setting next memory powerstate for bank %0x while pwrdm-RET to %0x\n",
+                pwrdm->name, bank, pwrst);
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_set_mem_retst)
+               ret = arch_pwrdm->pwrdm_set_mem_retst(pwrdm, bank, pwrst);
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_logic_pwrst - get current powerdomain logic retention power state
+ * @pwrdm: struct powerdomain * to get current logic retention power state
+ *
+ * Return the power state that the logic portion of powerdomain @pwrdm
+ * will enter when the powerdomain enters retention.  Returns -EINVAL
+ * if the powerdomain pointer is null or returns the logic retention
+ * power state upon success.
+ */
+int pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_logic_pwrst)
+               ret = arch_pwrdm->pwrdm_read_logic_pwrst(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_prev_logic_pwrst - get previous powerdomain logic power state
+ * @pwrdm: struct powerdomain * to get previous logic power state
+ *
+ * Return the powerdomain @pwrdm's previous logic power state.  Returns
+ * -EINVAL if the powerdomain pointer is null or returns the previous
+ * logic power state upon success.
+ */
+int pwrdm_read_prev_logic_pwrst(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_logic_pwrst)
+               ret = arch_pwrdm->pwrdm_read_prev_logic_pwrst(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_logic_retst - get next powerdomain logic power state
+ * @pwrdm: struct powerdomain * to get next logic power state
+ *
+ * Return the powerdomain pwrdm's logic power state.  Returns -EINVAL
+ * if the powerdomain pointer is null or returns the next logic
+ * power state upon success.
+ */
+int pwrdm_read_logic_retst(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return -EINVAL;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_logic_retst)
+               ret = arch_pwrdm->pwrdm_read_logic_retst(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_mem_pwrst - get current memory bank power state
+ * @pwrdm: struct powerdomain * to get current memory bank power state
+ * @bank: memory bank number (0-3)
+ *
+ * Return the powerdomain @pwrdm's current memory power state for bank
+ * @bank.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
+ * the target memory bank does not exist or is not controllable, or
+ * returns the current memory power state upon success.
+ */
+int pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return ret;
+
+       if (pwrdm->banks < (bank + 1))
+               return ret;
+
+       if (pwrdm->flags & PWRDM_HAS_MPU_QUIRK)
+               bank = 1;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_mem_pwrst)
+               ret = arch_pwrdm->pwrdm_read_mem_pwrst(pwrdm, bank);
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_prev_mem_pwrst - get previous memory bank power state
+ * @pwrdm: struct powerdomain * to get previous memory bank power state
+ * @bank: memory bank number (0-3)
+ *
+ * Return the powerdomain @pwrdm's previous memory power state for
+ * bank @bank.  Returns -EINVAL if the powerdomain pointer is null,
+ * -EEXIST if the target memory bank does not exist or is not
+ * controllable, or returns the previous memory power state upon
+ * success.
+ */
+int pwrdm_read_prev_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return ret;
+
+       if (pwrdm->banks < (bank + 1))
+               return ret;
+
+       if (pwrdm->flags & PWRDM_HAS_MPU_QUIRK)
+               bank = 1;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_mem_pwrst)
+               ret = arch_pwrdm->pwrdm_read_prev_mem_pwrst(pwrdm, bank);
+
+       return ret;
+}
+
+/**
+ * pwrdm_read_mem_retst - get next memory bank power state
+ * @pwrdm: struct powerdomain * to get mext memory bank power state
+ * @bank: memory bank number (0-3)
+ *
+ * Return the powerdomain pwrdm's next memory power state for bank
+ * x.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
+ * the target memory bank does not exist or is not controllable, or
+ * returns the next memory power state upon success.
+ */
+int pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return ret;
+
+       if (pwrdm->banks < (bank + 1))
+               return ret;
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_read_mem_retst)
+               ret = arch_pwrdm->pwrdm_read_mem_retst(pwrdm, bank);
+
+       return ret;
+}
+
+/**
+ * pwrdm_clear_all_prev_pwrst - clear previous powerstate register for a pwrdm
+ * @pwrdm: struct powerdomain * to clear
+ *
+ * Clear the powerdomain's previous power state register @pwrdm.
+ * Clears the entire register, including logic and memory bank
+ * previous power states.  Returns -EINVAL if the powerdomain pointer
+ * is null, or returns 0 upon success.
+ */
+int pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return ret;
+
+       /*
+        * XXX should get the powerdomain's current state here;
+        * warn & fail if it is not ON.
+        */
+
+       pr_debug("powerdomain: %s: clearing previous power state reg\n",
+                pwrdm->name);
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_clear_all_prev_pwrst)
+               ret = arch_pwrdm->pwrdm_clear_all_prev_pwrst(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_enable_hdwr_sar - enable automatic hardware SAR for a pwrdm
+ * @pwrdm: struct powerdomain *
+ *
+ * Enable automatic context save-and-restore upon power state change
+ * for some devices in the powerdomain @pwrdm.  Warning: this only
+ * affects a subset of devices in a powerdomain; check the TRM
+ * closely.  Returns -EINVAL if the powerdomain pointer is null or if
+ * the powerdomain does not support automatic save-and-restore, or
+ * returns 0 upon success.
+ */
+int pwrdm_enable_hdwr_sar(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return ret;
+
+       if (!(pwrdm->flags & PWRDM_HAS_HDWR_SAR))
+               return ret;
+
+       pr_debug("powerdomain: %s: setting SAVEANDRESTORE bit\n", pwrdm->name);
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_enable_hdwr_sar)
+               ret = arch_pwrdm->pwrdm_enable_hdwr_sar(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_disable_hdwr_sar - disable automatic hardware SAR for a pwrdm
+ * @pwrdm: struct powerdomain *
+ *
+ * Disable automatic context save-and-restore upon power state change
+ * for some devices in the powerdomain @pwrdm.  Warning: this only
+ * affects a subset of devices in a powerdomain; check the TRM
+ * closely.  Returns -EINVAL if the powerdomain pointer is null or if
+ * the powerdomain does not support automatic save-and-restore, or
+ * returns 0 upon success.
+ */
+int pwrdm_disable_hdwr_sar(struct powerdomain *pwrdm)
+{
+       int ret = -EINVAL;
+
+       if (!pwrdm)
+               return ret;
+
+       if (!(pwrdm->flags & PWRDM_HAS_HDWR_SAR))
+               return ret;
+
+       pr_debug("powerdomain: %s: clearing SAVEANDRESTORE bit\n", pwrdm->name);
+
+       if (arch_pwrdm && arch_pwrdm->pwrdm_disable_hdwr_sar)
+               ret = arch_pwrdm->pwrdm_disable_hdwr_sar(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_has_hdwr_sar - test whether powerdomain supports hardware SAR
+ * @pwrdm: struct powerdomain *
+ *
+ * Returns 1 if powerdomain @pwrdm supports hardware save-and-restore
+ * for some devices, or 0 if it does not.
+ */
+bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm)
+{
+       return (pwrdm && pwrdm->flags & PWRDM_HAS_HDWR_SAR) ? 1 : 0;
+}
+
+int pwrdm_state_switch_nolock(struct powerdomain *pwrdm)
+{
+       int ret;
+
+       if (!pwrdm || !arch_pwrdm)
+               return -EINVAL;
+
+       ret = arch_pwrdm->pwrdm_wait_transition(pwrdm);
+       if (!ret)
+               ret = _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);
+
+       return ret;
+}
+
+int __deprecated pwrdm_state_switch(struct powerdomain *pwrdm)
+{
+       int ret;
+
+       pwrdm_lock(pwrdm);
+       ret = pwrdm_state_switch_nolock(pwrdm);
+       pwrdm_unlock(pwrdm);
+
+       return ret;
+}
+
+int pwrdm_pre_transition(struct powerdomain *pwrdm)
+{
+       if (pwrdm)
+               _pwrdm_pre_transition_cb(pwrdm, NULL);
+       else
+               pwrdm_for_each(_pwrdm_pre_transition_cb, NULL);
+
+       return 0;
+}
+
+int pwrdm_post_transition(struct powerdomain *pwrdm)
+{
+       if (pwrdm)
+               _pwrdm_post_transition_cb(pwrdm, NULL);
+       else
+               pwrdm_for_each(_pwrdm_post_transition_cb, NULL);
+
+       return 0;
+}
+
+/**
+ * pwrdm_get_valid_lp_state() - Find best match deep power state
+ * @pwrdm:     power domain for which we want to find best match
+ * @is_logic_state: Are we looking for logic state match here? Should
+ *                 be one of PWRDM_xxx macro values
+ * @req_state: requested power state
+ *
+ * Returns: closest match for requested power state. default fallback
+ * is RET for logic state and ON for power state.
+ *
+ * This does a search from the power domain data looking for the
+ * closest valid power domain state that the hardware can achieve.
+ * PRCM definitions for PWRSTCTRL allows us to program whatever
+ * configuration we'd like, and PRCM will actually attempt such
+ * a transition, however if the powerdomain does not actually support it,
+ * we endup with a hung system. The valid power domain states are already
+ * available in our powerdomain data files. So this function tries to do
+ * the following:
+ * a) find if we have an exact match to the request - no issues.
+ * b) else find if a deeper power state is possible.
+ * c) failing which, it tries to find closest higher power state for the
+ * request.
+ */
+u8 pwrdm_get_valid_lp_state(struct powerdomain *pwrdm,
+                           bool is_logic_state, u8 req_state)
+{
+       u8 pwrdm_states = is_logic_state ? pwrdm->pwrsts_logic_ret :
+                       pwrdm->pwrsts;
+       /* For logic, ret is highest and others, ON is highest */
+       u8 default_pwrst = is_logic_state ? PWRDM_POWER_RET : PWRDM_POWER_ON;
+       u8 new_pwrst;
+       bool found;
+
+       /* If it is already supported, nothing to search */
+       if (pwrdm_states & BIT(req_state))
+               return req_state;
+
+       if (!req_state)
+               goto up_search;
+
+       /*
+        * So, we dont have a exact match
+        * Can we get a deeper power state match?
+        */
+       new_pwrst = req_state - 1;
+       found = true;
+       while (!(pwrdm_states & BIT(new_pwrst))) {
+               /* No match even at OFF? Not available */
+               if (new_pwrst == PWRDM_POWER_OFF) {
+                       found = false;
+                       break;
+               }
+               new_pwrst--;
+       }
+
+       if (found)
+               goto done;
+
+up_search:
+       /* OK, no deeper ones, can we get a higher match? */
+       new_pwrst = req_state + 1;
+       while (!(pwrdm_states & BIT(new_pwrst))) {
+               if (new_pwrst > PWRDM_POWER_ON) {
+                       WARN(1, "powerdomain: %s: Fix max powerstate to ON\n",
+                            pwrdm->name);
+                       return PWRDM_POWER_ON;
+               }
+
+               if (new_pwrst == default_pwrst)
+                       break;
+               new_pwrst++;
+       }
+done:
+       return new_pwrst;
+}
+
+/**
+ * omap_set_pwrdm_state - change a powerdomain's current power state
+ * @pwrdm: struct powerdomain * to change the power state of
+ * @pwrst: power state to change to
+ *
+ * Change the current hardware power state of the powerdomain
+ * represented by @pwrdm to the power state represented by @pwrst.
+ * Returns -EINVAL if @pwrdm is null or invalid or if the
+ * powerdomain's current power state could not be read, or returns 0
+ * upon success or if @pwrdm does not support @pwrst or any
+ * lower-power state.  XXX Should not return 0 if the @pwrdm does not
+ * support @pwrst or any lower-power state: this should be an error.
+ */
+int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
+{
+       u8 next_pwrst, sleep_switch;
+       int curr_pwrst;
+       int ret = 0;
+       bool hwsup = false;
+
+       if (!pwrdm || IS_ERR(pwrdm))
+               return -EINVAL;
+
+       while (!(pwrdm->pwrsts & (1 << pwrst))) {
+               if (pwrst == PWRDM_POWER_OFF)
+                       return ret;
+               pwrst--;
+       }
+
+       pwrdm_lock(pwrdm);
+
+       curr_pwrst = pwrdm_read_pwrst(pwrdm);
+       if (curr_pwrst < 0) {
+               ret = -EINVAL;
+               goto osps_out;
+       }
+
+       next_pwrst = pwrdm_read_next_pwrst(pwrdm);
+       if (curr_pwrst == pwrst && next_pwrst == pwrst)
+               goto osps_out;
+
+       sleep_switch = _pwrdm_save_clkdm_state_and_activate(pwrdm, curr_pwrst,
+                                                           pwrst, &hwsup);
+
+       ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
+       if (ret)
+               pr_err("%s: unable to set power state of powerdomain: %s\n",
+                      __func__, pwrdm->name);
+
+       _pwrdm_restore_clkdm_state(pwrdm, sleep_switch, hwsup);
+
+osps_out:
+       pwrdm_unlock(pwrdm);
+
+       return ret;
+}
+
+/**
+ * pwrdm_get_context_loss_count - get powerdomain's context loss count
+ * @pwrdm: struct powerdomain * to wait for
+ *
+ * Context loss count is the sum of powerdomain off-mode counter, the
+ * logic off counter and the per-bank memory off counter.  Returns negative
+ * (and WARNs) upon error, otherwise, returns the context loss count.
+ */
+int pwrdm_get_context_loss_count(struct powerdomain *pwrdm)
+{
+       int i, count;
+
+       if (!pwrdm) {
+               WARN(1, "powerdomain: %s: pwrdm is null\n", __func__);
+               return -ENODEV;
+       }
+
+       count = pwrdm->state_counter[PWRDM_POWER_OFF];
+       count += pwrdm->ret_logic_off_counter;
+
+       for (i = 0; i < pwrdm->banks; i++)
+               count += pwrdm->ret_mem_off_counter[i];
+
+       /*
+        * Context loss count has to be a non-negative value. Clear the sign
+        * bit to get a value range from 0 to INT_MAX.
+        */
+       count &= INT_MAX;
+
+       pr_debug("powerdomain: %s: context loss count = %d\n",
+                pwrdm->name, count);
+
+       return count;
+}
+
+/**
+ * pwrdm_can_ever_lose_context - can this powerdomain ever lose context?
+ * @pwrdm: struct powerdomain *
+ *
+ * Given a struct powerdomain * @pwrdm, returns 1 if the powerdomain
+ * can lose either memory or logic context or if @pwrdm is invalid, or
+ * returns 0 otherwise.  This function is not concerned with how the
+ * powerdomain registers are programmed (i.e., to go off or not); it's
+ * concerned with whether it's ever possible for this powerdomain to
+ * go off while some other part of the chip is active.  This function
+ * assumes that every powerdomain can go to either ON or INACTIVE.
+ */
+bool pwrdm_can_ever_lose_context(struct powerdomain *pwrdm)
+{
+       int i;
+
+       if (!pwrdm) {
+               pr_debug("powerdomain: %s: invalid powerdomain pointer\n",
+                        __func__);
+               return 1;
+       }
+
+       if (pwrdm->pwrsts & PWRSTS_OFF)
+               return 1;
+
+       if (pwrdm->pwrsts & PWRSTS_RET) {
+               if (pwrdm->pwrsts_logic_ret & PWRSTS_OFF)
+                       return 1;
+
+               for (i = 0; i < pwrdm->banks; i++)
+                       if (pwrdm->pwrsts_mem_ret[i] & PWRSTS_OFF)
+                               return 1;
+       }
+
+       for (i = 0; i < pwrdm->banks; i++)
+               if (pwrdm->pwrsts_mem_on[i] & PWRSTS_OFF)
+                       return 1;
+
+       return 0;
+}