@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
+#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <trace/events/power.h>
@@ -104,6 +105,12 @@ static int _pwrdm_register(struct powerdomain *pwrdm)
for (i = 0; i < pwrdm->banks; i++)
pwrdm->ret_mem_off_counter[i] = 0;
+ /* Initialize the per-od wake-up constraints list and spinlock */
+ spin_lock_init(&pwrdm->wkup_lat_plist_lock);
+ plist_head_init(&pwrdm->wkup_lat_plist_head,
+ &pwrdm->wkup_lat_plist_lock);
+
+ /* Initialize the pwrdm state */
pwrdm_wait_transition(pwrdm);
pwrdm->state = pwrdm_read_pwrst(pwrdm);
pwrdm->state_counter[pwrdm->state] = 1;
@@ -191,6 +198,103 @@ static int _pwrdm_post_transition_cb(struct powerdomain *pwrdm, void *unused)
return 0;
}
+/**
+ * pwrdm_wakeuplat_update_pwrst - Update power domain power state if needed
+ * @pwrdm: struct powerdomain * to which requesting device belongs to.
+ * @min_latency: the allowed wake-up latency for the given power domain. A
+ * value of 0 means 'no constraint' on the pwrdm.
+ *
+ * Finds the power domain next power state that fulfills the constraint.
+ * Programs a new target state if it is different from current power state.
+ *
+ * Note about PM QOS: the MPU and CORE power domains get the next power
+ * state via cpuidle, which get the strongest wake-up latency constraint
+ * by querying PM QOS. The usage of PM QOS is temporary, until a generic
+ * solution is in place.
+ * The power domains other then MPU and CORE get the next power state
+ * programmed directly in the registers.
+ *
+ * Returns 0 upon success.
+ */
+static int pwrdm_wakeuplat_update_pwrst(struct powerdomain *pwrdm,
+ long min_latency)
+{
+ int ret = 0, new_state = 0;
+
+ if (!pwrdm) {
+ WARN(1, "powerdomain: %s: invalid parameter(s)", __func__);
+ return -EINVAL;
+ }
+
+ /*
+ * Apply constraints to MPU and CORE via the PM QOS API.
+ * Every power domain struct has a pm_qos_request_list field
+ */
+ if (pwrdm->flags & PWRDM_USES_PM_QOS_CONSTRAINTS) {
+ if (pm_qos_request_active(&pwrdm->pm_qos_request))
+ pm_qos_remove_request(&pwrdm->pm_qos_request);
+
+ if (min_latency > 0) {
+ pm_qos_add_request(&pwrdm->pm_qos_request,
+ PM_QOS_CPU_DMA_LATENCY,
+ min_latency);
+ pr_debug("powerdomain: %s: pwrdm %s: "
+ "adding a PM_QOS_CPU_DMA_LATENCY request, "
+ "min_latency=%ld\n", __func__, pwrdm->name,
+ min_latency);
+ }
+
+ return 0;
+ }
+
+ /*
+ * Apply constraints to pwrdm other than MPU and CORE by programming
+ * the pwrdm next power state.
+ */
+
+ /* Find power state with wakeup latency < minimum constraint */
+ for (new_state = 0x0; new_state < PWRDM_MAX_PWRSTS; new_state++) {
+ if (min_latency == 0 ||
+ pwrdm->wakeup_lat[new_state] <= min_latency)
+ break;
+ }
+
+ switch (new_state) {
+ case PWRDM_FUNC_PWRST_OFF:
+ new_state = PWRDM_POWER_OFF;
+ break;
+ case PWRDM_FUNC_PWRST_OSWR:
+ pwrdm_set_logic_retst(pwrdm, PWRDM_POWER_OFF);
+ new_state = PWRDM_POWER_RET;
+ break;
+ case PWRDM_FUNC_PWRST_CSWR:
+ pwrdm_set_logic_retst(pwrdm, PWRDM_POWER_RET);
+ new_state = PWRDM_POWER_RET;
+ break;
+ case PWRDM_FUNC_PWRST_INACTIVE:
+ new_state = PWRDM_POWER_INACTIVE;
+ break;
+ case PWRDM_FUNC_PWRST_ON:
+ new_state = PWRDM_POWER_ON;
+ break;
+ default:
+ pr_warn("powerdomain: requested latency constraint not "
+ "supported %s set to ON state\n", pwrdm->name);
+ new_state = PWRDM_POWER_ON;
+ break;
+ }
+
+ if (pwrdm_read_pwrst(pwrdm) != new_state)
+ ret = omap_set_pwrdm_state(pwrdm, new_state);
+
+ pr_debug("powerdomain: %s pwrst: curr=%d, prev=%d next=%d "
+ "min_latency=%ld, set_state=%d\n", pwrdm->name,
+ pwrdm_read_pwrst(pwrdm), pwrdm_read_prev_pwrst(pwrdm),
+ pwrdm_read_next_pwrst(pwrdm), min_latency, new_state);
+
+ return ret;
+}
+
/* Public functions */
/**
@@ -930,6 +1034,110 @@ int pwrdm_post_transition(void)
return 0;
}
+/*
+ * pwrdm_set_wkup_lat_constraint - Set/update/remove a powerdomain wakeup
+ * latency constraint and apply it
+ * @pwrdm: struct powerdomain * which the constraint applies to
+ * @cookie: constraint identifier, used for tracking.
+ * @min_latency: minimum wakeup latency constraint (in microseconds) for
+ * the given pwrdm. The value of 0 removes the constraint.
+ *
+ * Tracks the constraints by @cookie.
+ * Constraint set/update: Adds a new entry to powerdomain's wake-up latency
+ * constraint list.
+ * If the constraint identifier already exists in the list, the old value is
+ * overwritten.
+ * Constraint removal: Removes the identifier's entry from powerdomain's
+ * wakeup latency constraint list.
+ *
+ * Applies the strongest constraint value for the given pwrdm by calling
+ * pwrdm_wakeuplat_update_pwrst.
+ *
+ * Returns 0 upon success or a negative value in case of error.
+ *
+ * The caller must check the validity of the parameters.
+ */
+int pwrdm_set_wkup_lat_constraint(struct powerdomain *pwrdm, void *cookie,
+ long min_latency)
+{
+ struct pwrdm_wkup_constraints_entry *user = NULL, *tmp_user;
+ int ret = 0;
+ long value = 0;
+ unsigned long flags;
+
+ pr_debug("powerdomain: %s: pwrdm %s, cookie=0x%p, min_latency=%ld\n",
+ __func__, pwrdm->name, cookie, min_latency);
+
+ /* Check if there already is a constraint for cookie */
+ spin_lock_irqsave(&pwrdm->wkup_lat_plist_lock, flags);
+ plist_for_each_entry(tmp_user, &pwrdm->wkup_lat_plist_head, node) {
+ if (tmp_user->cookie == cookie) {
+ user = tmp_user;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&pwrdm->wkup_lat_plist_lock, flags);
+
+ if (min_latency > 0) {
+ /* Nothing to update, job done */
+ if (user && (user->node.prio == min_latency))
+ goto exit_ok;
+
+ /* Add new entry to the list or update existing request */
+ if (!user) {
+ user = kzalloc(
+ sizeof(struct pwrdm_wkup_constraints_entry),
+ GFP_KERNEL);
+ if (!user) {
+ pr_err("%s: FATAL ERROR: kzalloc failed\n",
+ __func__);
+ ret = -ENOMEM;
+ goto exit_error;
+ }
+ user->cookie = cookie;
+ } else {
+ spin_lock_irqsave(&pwrdm->wkup_lat_plist_lock, flags);
+ plist_del(&user->node, &pwrdm->wkup_lat_plist_head);
+ spin_unlock_irqrestore(&pwrdm->wkup_lat_plist_lock,
+ flags);
+ }
+
+ spin_lock_irqsave(&pwrdm->wkup_lat_plist_lock, flags);
+ plist_node_init(&user->node, min_latency);
+ plist_add(&user->node, &pwrdm->wkup_lat_plist_head);
+ spin_unlock_irqrestore(&pwrdm->wkup_lat_plist_lock, flags);
+ } else {
+ /* Remove the constraint from the list */
+ if (!user) {
+ pr_err("%s: Error: no prior constraint to release\n",
+ __func__);
+ ret = -EINVAL;
+ goto exit_error;
+ }
+
+ spin_lock_irqsave(&pwrdm->wkup_lat_plist_lock, flags);
+ plist_del(&user->node, &pwrdm->wkup_lat_plist_head);
+ spin_unlock_irqrestore(&pwrdm->wkup_lat_plist_lock, flags);
+ kfree(user);
+ }
+
+exit_ok:
+ /* Find the strongest constraint from the list */
+ if (!plist_head_empty(&pwrdm->wkup_lat_plist_head)) {
+ spin_lock_irqsave(&pwrdm->wkup_lat_plist_lock, flags);
+ value = plist_first(&pwrdm->wkup_lat_plist_head)->prio;
+ spin_unlock_irqrestore(&pwrdm->wkup_lat_plist_lock, flags);
+ }
+
+ /* Apply the constraint to the pwrdm */
+ pr_debug("powerdomain: %s: pwrdm %s, value=%ld\n",
+ __func__, pwrdm->name, value);
+ pwrdm_wakeuplat_update_pwrst(pwrdm, value);
+
+exit_error:
+ return ret;
+}
+
/**
* pwrdm_get_context_loss_count - get powerdomain's context loss count
* @pwrdm: struct powerdomain * to wait for
@@ -19,7 +19,10 @@
#include <linux/types.h>
#include <linux/list.h>
-
+#include <linux/plist.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/pm_qos_params.h>
#include <linux/atomic.h>
#include <plat/cpu.h>
@@ -43,6 +46,16 @@
#define PWRSTS_RET_ON (PWRSTS_RET | PWRSTS_ON)
#define PWRSTS_OFF_RET_ON (PWRSTS_OFF_RET | PWRSTS_ON)
+/* Powerdomain functional power states */
+#define PWRDM_FUNC_PWRST_OFF 0x0
+#define PWRDM_FUNC_PWRST_OSWR 0x1
+#define PWRDM_FUNC_PWRST_CSWR 0x2
+#define PWRDM_FUNC_PWRST_INACTIVE 0x3
+#define PWRDM_FUNC_PWRST_ON 0x4
+
+#define PWRDM_MAX_FUNC_PWRSTS 5
+
+#define UNSUP_STATE -1
/* Powerdomain flags */
#define PWRDM_HAS_HDWR_SAR (1 << 0) /* hardware save-and-restore support */
@@ -56,6 +69,12 @@
* state without waking up the
* powerdomain
*/
+#define PWRDM_USES_PM_QOS_CONSTRAINTS (1 << 3) /* Uses the PM QOS framework
+ * for wake-up latency
+ * constraints.
+ * Note: temporary until the
+ * generic OMAP PM is in place
+ */
/*
* Number of memory banks that are power-controllable. On OMAP4430, the
@@ -93,7 +112,13 @@ struct powerdomain;
* @state_counter:
* @timer:
* @state_timer:
- *
+ * @wakeup_lat: wakeup latencies (in us) for possible powerdomain power states
+ * Note about the wakeup latencies ordering: the values must be sorted
+ * in decremental order
+ * @wkup_lat_plist_head: pwrdm wake-up latency constraints list
+ * @wkup_lat_plist_lock: spinlock that protects the constraints lists
+ * @pm_qos_request: PM QOS handle, only used to control the MPU and CORE power
+ * domains states; to be removed when a generic solution is in place.
* @prcm_partition possible values are defined in mach-omap2/prcm44xx.h.
*/
struct powerdomain {
@@ -118,6 +143,16 @@ struct powerdomain {
s64 timer;
s64 state_timer[PWRDM_MAX_PWRSTS];
#endif
+ const u32 wakeup_lat[PWRDM_MAX_FUNC_PWRSTS];
+ struct plist_head wkup_lat_plist_head;
+ spinlock_t wkup_lat_plist_lock;
+ struct pm_qos_request_list pm_qos_request;
+};
+
+/* Linked list for the wake-up latency constraints */
+struct pwrdm_wkup_constraints_entry {
+ void *cookie;
+ struct plist_node node;
};
/**
@@ -207,6 +242,9 @@ int pwrdm_clkdm_state_switch(struct clockdomain *clkdm);
int pwrdm_pre_transition(void);
int pwrdm_post_transition(void);
int pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm);
+
+int pwrdm_set_wkup_lat_constraint(struct powerdomain *pwrdm, void *cookie,
+ long min_latency);
u32 pwrdm_get_context_loss_count(struct powerdomain *pwrdm);
bool pwrdm_can_ever_lose_context(struct powerdomain *pwrdm);