OMAP: add PM_CONSTRAINTS framework

363 lines not on this page · raw message

index 9af0847..9860630 100644
@@ -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

78 lines not on this page · raw message

index 469a920..72fe278 100644
@@ -31,6 +31,13 @@
 
 /*
  * Powerdomains
+ *
+ * The wakeup_lat values are derived from measurements on
+ * the actual target.
+ *
+ * Note: the latency figures are preliminary and only used
+ * for the constraints framework validation.
+ * Actual figures and measurements conditions shall be added.
  */
 
 static struct powerdomain iva2_pwrdm = {

@@ -52,6 +59,13 @@ static struct powerdomain iva2_pwrdm = {
 		[2] = PWRSTS_OFF_ON,
 		[3] = PWRSTS_ON,
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 1100,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 350,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain mpu_3xxx_pwrdm = {

@@ -60,7 +74,8 @@ static struct powerdomain mpu_3xxx_pwrdm = {
 	.omap_chip	  = OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
 	.pwrsts		  = PWRSTS_OFF_RET_ON,
 	.pwrsts_logic_ret = PWRSTS_OFF_RET,
-	.flags		  = PWRDM_HAS_MPU_QUIRK,
+	.flags		  = PWRDM_HAS_MPU_QUIRK |
+			    PWRDM_USES_PM_QOS_CONSTRAINTS,
 	.banks		  = 1,
 	.pwrsts_mem_ret	  = {
 		[0] = PWRSTS_OFF_RET,

@@ -68,6 +83,13 @@ static struct powerdomain mpu_3xxx_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRSTS_OFF_ON,
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 95,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 45,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 /*

@@ -90,6 +112,7 @@ static struct powerdomain core_3xxx_pre_es3_1_pwrdm = {
 	.pwrsts		  = PWRSTS_OFF_RET_ON,
 	.pwrsts_logic_ret = PWRSTS_OFF_RET,
 	.banks		  = 2,
+	.flags		  = PWRDM_USES_PM_QOS_CONSTRAINTS,
 	.pwrsts_mem_ret	  = {
 		[0] = PWRSTS_OFF_RET,	 /* MEM1RETSTATE */
 		[1] = PWRSTS_OFF_RET,	 /* MEM2RETSTATE */

@@ -98,6 +121,13 @@ static struct powerdomain core_3xxx_pre_es3_1_pwrdm = {
 		[0] = PWRSTS_OFF_RET_ON, /* MEM1ONSTATE */
 		[1] = PWRSTS_OFF_RET_ON, /* MEM2ONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 100,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 60,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain core_3xxx_es3_1_pwrdm = {

@@ -111,7 +141,8 @@ static struct powerdomain core_3xxx_es3_1_pwrdm = {
 	 * Setting the SAR flag for errata ID i478 which applies
 	 *  to 3430 <= ES3.1
 	 */
-	.flags		  = PWRDM_HAS_HDWR_SAR, /* for USBTLL only */
+	.flags		  = PWRDM_HAS_HDWR_SAR /* for USBTLL only */ |
+			    PWRDM_USES_PM_QOS_CONSTRAINTS,
 	.banks		  = 2,
 	.pwrsts_mem_ret	  = {
 		[0] = PWRSTS_OFF_RET,	 /* MEM1RETSTATE */

@@ -121,6 +152,13 @@ static struct powerdomain core_3xxx_es3_1_pwrdm = {
 		[0] = PWRSTS_OFF_RET_ON, /* MEM1ONSTATE */
 		[1] = PWRSTS_OFF_RET_ON, /* MEM2ONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 100,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 60,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain dss_pwrdm = {

@@ -136,6 +174,13 @@ static struct powerdomain dss_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRSTS_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 70,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 20,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 /*

@@ -157,6 +202,13 @@ static struct powerdomain sgx_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRSTS_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 1000,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain cam_pwrdm = {

@@ -172,6 +224,13 @@ static struct powerdomain cam_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRSTS_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 850,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 35,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain per_pwrdm = {

@@ -187,6 +246,13 @@ static struct powerdomain per_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRSTS_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 200,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 110,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain emu_pwrdm = {

@@ -201,6 +267,13 @@ static struct powerdomain neon_pwrdm = {
 	.omap_chip	  = OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
 	.pwrsts		  = PWRSTS_OFF_RET_ON,
 	.pwrsts_logic_ret = PWRSTS_RET,
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 200,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 35,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain usbhost_pwrdm = {

@@ -223,6 +296,13 @@ static struct powerdomain usbhost_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRSTS_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 800,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 150,
+		[PWRDM_FUNC_PWRST_INACTIVE] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain dpll1_pwrdm = {

index e034294..af0441e 100644
@@ -142,6 +142,7 @@
 #include "powerdomain.h"
 #include <plat/clock.h>
 #include <plat/omap_hwmod.h>
+#include <plat/omap_device.h>
 #include <plat/prcm.h>
 
 #include "cm2xxx_3xxx.h"

@@ -2322,11 +2323,34 @@ ohsps_unlock:
 	return ret;
 }
 
+/*
+ * omap_hwmod_set_wkup_constraint- set/release a wake-up latency constraint
+ *
+ * @oh: struct omap_hwmod* to which the target device belongs to.
+ * @cookie: identifier of the constraints list for @oh.
+ * @min_latency: the minimum allowed wake-up latency for @oh.
+ *
+ * Returns 0 upon success.
+ */
+int omap_hwmod_set_wkup_lat_constraint(struct omap_hwmod *oh,
+				       void *cookie, long min_latency)
+{
+	struct powerdomain *pwrdm = omap_hwmod_get_pwrdm(oh);
+
+	if (!pwrdm) {
+		pr_err("%s: Error: could not find powerdomain "
+		       "for %s\n", __func__, oh->name);
+		return -EINVAL;
+	}
+
+	return pwrdm_set_wkup_lat_constraint(pwrdm, cookie, min_latency);
+}
+
 /**
  * omap_hwmod_get_context_loss_count - get lost context count
  * @oh: struct omap_hwmod *
  *
- * Query the powerdomain of of @oh to get the context loss
+ * Query the powerdomain of @oh to get the context loss
  * count for this device.
  *
  * Returns the context loss count of the powerdomain assocated with @oh

index 1adea9c..bf9e81d 100644
@@ -598,6 +598,8 @@ int omap_hwmod_for_each_by_class(const char *classname,
 				 void *user);
 
 int omap_hwmod_set_postsetup_state(struct omap_hwmod *oh, u8 state);
+int omap_hwmod_set_wkup_lat_constraint(struct omap_hwmod *oh, void *cookie,
+				       long min_latency);
 u32 omap_hwmod_get_context_loss_count(struct omap_hwmod *oh);
 
 int omap_hwmod_no_setup_reset(struct omap_hwmod *oh);

index c0a7520..5f19cb2 100644
@@ -70,6 +70,10 @@ void omap_pm_if_exit(void);
  * Device-driver-originated constraints (via board-*.c files, platform_data)
  */
 
+enum omap_pm_constraint_class {
+	OMAP_PM_CONSTRAINT_WKUP_LAT,
+	OMAP_PM_CONSTRAINT_THROUGHPUT
+};
 
 /**
  * omap_pm_set_max_mpu_wakeup_lat - set the maximum MPU wakeup latency

index e4c349f..9a47b47 100644
@@ -32,9 +32,11 @@
 #define __ARCH_ARM_PLAT_OMAP_INCLUDE_MACH_OMAP_DEVICE_H
 
 #include <linux/kernel.h>
+#include <linux/plist.h>
 #include <linux/platform_device.h>
 
 #include <plat/omap_hwmod.h>
+#include <plat/omap-pm.h>
 
 extern struct device omap_device_parent;
 

@@ -54,8 +56,8 @@ extern struct device omap_device_parent;
  * @pm_lat_level: array index of the last odpl entry executed - -1 if never
  * @dev_wakeup_lat: dev wakeup latency in nanoseconds
  * @_dev_wakeup_lat_limit: dev wakeup latency limit in nsec - set by OMAP PM
+ * @wkup_lat_plist_head: devices wake-up latency constraints list
  * @_state: one of OMAP_DEVICE_STATE_* (see above)
- * @flags: device flags
  *
  * Integrates omap_hwmod data into Linux platform_device.
  *

@@ -67,6 +69,7 @@ struct omap_device {
 	struct platform_device		pdev;
 	struct omap_hwmod		**hwmods;
 	struct omap_device_pm_latency	*pm_lats;
+	struct plist_head		wkup_lat_plist_head;
 	u32				dev_wakeup_lat;
 	u32				_dev_wakeup_lat_limit;
 	u8				pm_lats_cnt;

@@ -75,6 +78,13 @@ struct omap_device {
 	u8				_state;
 };
 
+/* Linked list for the devices constraints entries */
+struct omap_device_constraints_entry {
+	struct device			*dev;
+	struct device			*req_dev;
+	struct plist_node		node;
+};
+
 /* Device driver interface (call via platform_data fn ptrs) */
 
 int omap_device_enable(struct platform_device *pdev);

@@ -107,6 +117,9 @@ void __iomem *omap_device_get_rt_va(struct omap_device *od);
 int omap_device_align_pm_lat(struct platform_device *pdev,
 			     u32 new_wakeup_lat_limit);
 struct powerdomain *omap_device_get_pwrdm(struct omap_device *od);
+int omap_device_set_dev_constraint(enum omap_pm_constraint_class class,
+				   struct device *req_dev,
+				   struct device *dev, long t);
 u32 omap_device_get_context_loss_count(struct platform_device *pdev);
 
 /* Other */

213 lines not on this page · raw message

index c8b4e4c..805dba3 100644
@@ -24,6 +24,7 @@
 /* Interface documentation is in mach/omap-pm.h */
 #include <plat/omap-pm.h>
 #include <plat/omap_device.h>
+#include <plat/common.h>
 
 static bool off_mode_enabled;
 static u32 dummy_context_loss_counter;

@@ -32,119 +33,124 @@ static u32 dummy_context_loss_counter;
  * Device-driver-originated constraints (via board-*.c files)
  */
 
-int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t)
+/*
+ * Generic function to omap_device layer for the constraints API.
+ */
+static int _set_dev_constraint(enum omap_pm_constraint_class class,
+			       struct device *req_dev, struct device *dev,
+			       long t)
 {
-	if (!dev || t < -1) {
+	int ret = 0;
+
+	if (!req_dev || !dev || t < -1) {
 		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
 		return -EINVAL;
-	};
-
-	if (t == -1)
-		pr_debug("OMAP PM: remove max MPU wakeup latency constraint: "
-			 "dev %s\n", dev_name(dev));
-	else
-		pr_debug("OMAP PM: add max MPU wakeup latency constraint: "
-			 "dev %s, t = %ld usec\n", dev_name(dev), t);
+	}
 
-	/*
-	 * For current Linux, this needs to map the MPU to a
-	 * powerdomain, then go through the list of current max lat
-	 * constraints on the MPU and find the smallest.  If
-	 * the latency constraint has changed, the code should
-	 * recompute the state to enter for the next powerdomain
-	 * state.
-	 *
-	 * TI CDP code can call constraint_set here.
-	 */
+	/* Only valid for omap_devices */
+	if (dev->parent == &omap_device_parent) {
+		if (t == -1)
+			pr_debug("OMAP PM: remove constraint of class %d "
+				 "from req_dev %s on dev %s\n",
+				 class, dev_name(req_dev), dev_name(dev));
+		else
+			pr_debug("OMAP PM: add constraint of class %d "
+				 "from req_dev %s on dev %s, t = %ld\n",
+				 class, dev_name(req_dev), dev_name(dev), t);
+
+		ret = omap_device_set_dev_constraint(class, req_dev, dev, t);
+	} else {
+		pr_err("OMAP-PM: %s: Error: not an omap_device\n", __func__);
+		return -EINVAL;
+	}
 
-	return 0;
+	return ret;
 }
 
+/*
+ * omap_pm_set_min_bus_tput - set/release bus throughput constraints
+ */
 int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r)
 {
+	long t;
+	struct device *req_dev = NULL;
+
 	if (!dev || (agent_id != OCP_INITIATOR_AGENT &&
 	    agent_id != OCP_TARGET_AGENT)) {
 		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
 		return -EINVAL;
 	};
 
+	/*
+	 * This code calls the generic omap_device API function
+	 * _set_dev_constraint with the class OMAP_PM_CONSTRAINT_THROUGHPUT.
+	 * _set_dev_constraint should manage the constraints lists and call
+	 * the appropriate low level code that models the interconnect,
+	 * computes the required clock frequency, converts that to a VDD2
+	 * OPP ID and sets the VDD2 OPP appropriately.
+	 */
+
+	/*
+	 * A value of r == 0 removes the constraint. Convert it to the
+	 * generic _set_dev_constraint convention (-1 for constraint removal)
+	 */
 	if (r == 0)
-		pr_debug("OMAP PM: remove min bus tput constraint: "
-			 "dev %s for agent_id %d\n", dev_name(dev), agent_id);
+		t = -1;
 	else
-		pr_debug("OMAP PM: add min bus tput constraint: "
-			 "dev %s for agent_id %d: rate %ld KiB\n",
-			 dev_name(dev), agent_id, r);
+		t = r;
 
 	/*
-	 * This code should model the interconnect and compute the
-	 * required clock frequency, convert that to a VDD2 OPP ID, then
-	 * set the VDD2 OPP appropriately.
-	 *
-	 * TI CDP code can call constraint_set here on the VDD2 OPP.
+	 * Assign the device for L3 or L4 interconnect to req_dev,
+	 * based on the value of agent_id
 	 */
+	switch (agent_id) {
+	case OCP_INITIATOR_AGENT:
+		req_dev = omap2_get_l3_device();
+		break;
+	case OCP_TARGET_AGENT:
+		/* Fixme: need the device for L4 interconnect */
+		break;
+	}
 
-	return 0;
+	return _set_dev_constraint(OMAP_PM_CONSTRAINT_THROUGHPUT,
+				   req_dev, dev, t);
 }
 
+/*
+ * omap_pm_set_max_dev_wakeup_lat - set/release devices wake-up latency
+ * constraints
+ */
 int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
 				   long t)
 {
-	if (!req_dev || !dev || t < -1) {
-		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
-		return -EINVAL;
-	};
-
-	if (t == -1)
-		pr_debug("OMAP PM: remove max device latency constraint: "
-			 "dev %s\n", dev_name(dev));
-	else
-		pr_debug("OMAP PM: add max device latency constraint: "
-			 "dev %s, t = %ld usec\n", dev_name(dev), t);
-
-	/*
-	 * For current Linux, this needs to map the device to a
-	 * powerdomain, then go through the list of current max lat
-	 * constraints on that powerdomain and find the smallest.  If
-	 * the latency constraint has changed, the code should
-	 * recompute the state to enter for the next powerdomain
-	 * state.  Conceivably, this code should also determine
-	 * whether to actually disable the device clocks or not,
-	 * depending on how long it takes to re-enable the clocks.
-	 *
-	 * TI CDP code can call constraint_set here.
-	 */
-
-	return 0;
+	return _set_dev_constraint(OMAP_PM_CONSTRAINT_WKUP_LAT, req_dev,
+				   dev, t);
 }
 
-int omap_pm_set_max_sdma_lat(struct device *dev, long t)
+/*
+ * omap_pm_set_max_mpu_wakeup_lat - set/release MPU wake-up latency
+ * constraints
+ *
+ * Maps to _set_dev_constraint with OMAP_PM_CONSTRAINT_WKUP_LAT
+ * as constraint class and the MPU device as constraints target.
+ */
+int omap_pm_set_max_mpu_wakeup_lat(struct device *req_dev, long t)
 {
-	if (!dev || t < -1) {
-		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
-		return -EINVAL;
-	};
-
-	if (t == -1)
-		pr_debug("OMAP PM: remove max DMA latency constraint: "
-			 "dev %s\n", dev_name(dev));
-	else
-		pr_debug("OMAP PM: add max DMA latency constraint: "
-			 "dev %s, t = %ld usec\n", dev_name(dev), t);
-
-	/*
-	 * For current Linux PM QOS params, this code should scan the
-	 * list of maximum CPU and DMA latencies and select the
-	 * smallest, then set cpu_dma_latency pm_qos_param
-	 * accordingly.
-	 *
-	 * For future Linux PM QOS params, with separate CPU and DMA
-	 * latency params, this code should just set the dma_latency param.
-	 *
-	 * TI CDP code can call constraint_set here.
-	 */
+	return _set_dev_constraint(OMAP_PM_CONSTRAINT_WKUP_LAT, req_dev,
+				   omap2_get_mpuss_device(), t);
+}
 
-	return 0;
+/*
+ * omap_pm_set_max_sdma_lat - set/release SDMA start latency
+ * constraints
+ *
+ * Currently maps to _set_dev_constraint with OMAP_PM_CONSTRAINT_WKUP_LAT
+ * as constraint class and the L3 device as constraints target.
+ */
+int omap_pm_set_max_sdma_lat(struct device *req_dev, long t)
+{
+	return _set_dev_constraint(OMAP_PM_CONSTRAINT_WKUP_LAT, req_dev,
+				   omap2_get_l3_device(), t);
 }
 
 int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r)

index 0c5e3a4..8d202a7 100644
@@ -840,7 +840,7 @@ static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 	if (!pwrst)
 		return -ENOMEM;
 	pwrst->pwrdm = pwrdm;
-	pwrst->next_state = PWRDM_POWER_RET;
+	pwrst->next_state = pwrdm_read_next_pwrst(pwrdm);
 	list_add(&pwrst->node, &pwrst_list);
 
 	if (pwrdm_has_hdwr_sar(pwrdm))

index 59a870b..049efe9 100644
@@ -84,7 +84,7 @@ static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 	if (!pwrst)
 		return -ENOMEM;
 	pwrst->pwrdm = pwrdm;
-	pwrst->next_state = PWRDM_POWER_ON;
+	pwrdm->state = pwrdm_read_pwrst(pwrdm);
 	list_add(&pwrst->node, &pwrst_list);
 
 	return pwrdm_set_next_pwrst(pwrst->pwrdm, pwrst->next_state);

index 9860630..3294707 100644
@@ -78,6 +78,7 @@ static struct powerdomain *_pwrdm_lookup(const char *name)
 static int _pwrdm_register(struct powerdomain *pwrdm)
 {
 	int i;
+	int next_state = PWRDM_POWER_RET;
 
 	if (!pwrdm || !pwrdm->name)
 		return -EINVAL;

@@ -114,6 +115,10 @@ static int _pwrdm_register(struct powerdomain *pwrdm)
 	pwrdm_wait_transition(pwrdm);
 	pwrdm->state = pwrdm_read_pwrst(pwrdm);
 	pwrdm->state_counter[pwrdm->state] = 1;
+	/* Early init of the next power state */
+	if (cpu_is_omap44xx())
+		next_state = PWRDM_POWER_ON;
+	pwrdm_set_next_pwrst(pwrdm, next_state);
 
 	pr_debug("powerdomain: registered %s\n", pwrdm->name);