diff mbox

[RFC] OMAP PM: Device wakeup latency constraint framework

Message ID 1281469214-12176-1-git-send-email-vvardhan@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Vibhore Vardhan Aug. 10, 2010, 7:40 p.m. UTC
None
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index 6527ec3..16edec6 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -23,6 +23,7 @@ 
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/slab.h>
 
 #include <asm/atomic.h>
 
@@ -133,6 +134,13 @@  static int _pwrdm_register(struct powerdomain *pwrdm)
 	pwrdm->state = pwrdm_read_pwrst(pwrdm);
 	pwrdm->state_counter[pwrdm->state] = 1;
 
+	/* Initialize priority ordered list for wakeup latency constraint */
+	spin_lock_init(&pwrdm->wakeuplat_lock);
+	plist_head_init(&pwrdm->wakeuplat_dev_list, &pwrdm->wakeuplat_lock);
+
+	/* res_mutex protects res_list add and del ops */
+	mutex_init(&pwrdm->wakeuplat_mutex);
+
 	pr_debug("powerdomain: registered %s\n", pwrdm->name);
 
 	return 0;
@@ -1075,3 +1083,159 @@  int pwrdm_post_transition(void)
 	return 0;
 }
 
+/**
+ * pwrdm_wakeuplat_set_constraint - Set powerdomain wakeup latency constraint
+ * @pwrdm: struct powerdomain * to which requesting device belongs to
+ * @dev: struct device * of requesting device
+ * @t: wakeup latency constraint in microseconds
+ *
+ * Adds new entry to powerdomain's wakeup latency constraint list.
+ * If the requesting device already exists in the list, old value is
+ * overwritten. Checks whether current power state is still adequate.
+ * Returns -EINVAL if the powerdomain or device pointer is NULL,
+ * or -ENOMEM if kmalloc fails, or -ERANGE if constraint can't be met,
+ * or returns 0 upon success.
+ */
+int pwrdm_wakeuplat_set_constraint (struct powerdomain *pwrdm,
+				    struct device *dev, unsigned long t)
+{
+	struct  wakeuplat_dev_list *user;
+	int found = 0, ret = 0;
+
+	if (!pwrdm || !dev) {
+		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
+		return -EINVAL;
+	}
+
+	mutex_lock(&pwrdm->wakeuplat_mutex);
+
+	plist_for_each_entry(user, &pwrdm->wakeuplat_dev_list, node) {
+		if (user->dev == dev) {
+			found = 1;
+			break;
+		}
+	}
+
+	/* Add new entry to the list or update existing request */
+	if (found && user->constraint_us == t) {
+		goto exit_set;
+	} else if (!found) {
+		user = kzalloc(sizeof(struct wakeuplat_dev_list), GFP_KERNEL);
+		if (!user) {
+			pr_err("OMAP PM: FATAL ERROR: kzalloc failed\n");
+			ret = -ENOMEM;
+			goto exit_set;
+		}
+		user->dev = dev;
+	} else {
+		plist_del(&user->node, &pwrdm->wakeuplat_dev_list);
+	}
+
+	plist_node_init(&user->node, t);
+	plist_add(&user->node, &pwrdm->wakeuplat_dev_list);
+	user->node.prio = user->constraint_us = t;
+
+	ret = pwrdm_wakeuplat_update_pwrst(pwrdm);
+
+exit_set:
+	mutex_unlock(&pwrdm->wakeuplat_mutex);
+
+	return ret;
+}
+
+/**
+ * pwrdm_wakeuplat_release_constraint - Release powerdomain wkuplat constraint
+ * @pwrdm: struct powerdomain * to which requesting device belongs to
+ * @dev: struct device * of requesting device
+ *
+ * Removes device's entry from powerdomain's wakeup latency constraint list.
+ * Checks whether current power state is still adequate.
+ * Returns -EINVAL if the powerdomain or device pointer is NULL or
+ * no such entry exists in the list, or returns 0 upon success.
+ */
+int pwrdm_wakeuplat_release_constraint (struct powerdomain *pwrdm,
+					struct device *dev)
+{
+	struct wakeuplat_dev_list *user;
+	int found = 0, ret = 0;
+
+	if (!pwrdm || !dev) {
+		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
+		return -EINVAL;
+	}
+
+	mutex_lock(&pwrdm->wakeuplat_mutex);
+
+	plist_for_each_entry(user, &pwrdm->wakeuplat_dev_list, node) {
+		if (user->dev == dev) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found) {
+		pr_err("OMAP PM: Error: no prior constraint to release\n");
+		ret = -EINVAL;
+		goto exit_rls;
+	}
+
+	plist_del(&user->node, &pwrdm->wakeuplat_dev_list);
+	kfree(user);
+
+	ret = pwrdm_wakeuplat_update_pwrst(pwrdm);
+
+exit_rls:
+	mutex_unlock(&pwrdm->wakeuplat_mutex);
+
+	return ret;
+}
+
+/**
+ * pwrdm_wakeuplat_update_pwrst - Update power domain power state if needed
+ * @pwrdm: struct powerdomain * to which requesting device belongs to
+ *
+ * Finds minimum latency value from all entries in the list and
+ * the power domain power state neeting the constraint. Programs
+ * new state if it is different from current power state.
+ * Returns -EINVAL if the powerdomain or device pointer is NULL or
+ * no such entry exists in the list, or -ERANGE if constraint can't be met,
+ * or returns 0 upon success.
+ */
+int pwrdm_wakeuplat_update_pwrst(struct powerdomain *pwrdm)
+{
+	struct plist_node *node;
+	int ret = 0, new_state;
+	unsigned long min_latency = -1;
+
+	if (!plist_head_empty(&pwrdm->wakeuplat_dev_list)) {
+		node = plist_last(&pwrdm->wakeuplat_dev_list);
+		min_latency = node->prio;
+	}
+
+	/* Find power state with wakeup latency < minimum constraint. */
+	for (new_state = 0x0; new_state < PWRDM_MAX_PWRSTS; new_state++) {
+		if (min_latency == -1 ||
+			pwrdm->wakeup_lat[new_state] < min_latency)
+			break;
+	}
+
+	/* No power state wkuplat met constraint. Keep power domain ON. */
+	if (new_state == PWRDM_MAX_PWRSTS) {
+		new_state = PWRDM_FUNC_PWRST_ON;
+		ret = -ERANGE;
+	}
+
+	/* OSWR is not supported, set CSWR instead. TODO: add OSWR support */
+	if (new_state == PWRDM_FUNC_PWRST_OSWR)
+		new_state = PWRDM_FUNC_PWRST_CSWR;
+
+	if (pwrdm->state != new_state)
+		set_pwrdm_state(pwrdm, new_state);
+
+	pr_debug("OMAP PM: %s pwrst: curr= %d, prev= %d next= %d "
+			"wkuplat_min= %lu, 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;
+}
diff --git a/arch/arm/mach-omap2/powerdomains34xx.h b/arch/arm/mach-omap2/powerdomains34xx.h
index fa90486..7be94ea 100644
--- a/arch/arm/mach-omap2/powerdomains34xx.h
+++ b/arch/arm/mach-omap2/powerdomains34xx.h
@@ -57,6 +57,12 @@  static struct powerdomain iva2_pwrdm = {
 		[2] = PWRSTS_OFF_ON,
 		[3] = PWRDM_POWER_ON,
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 1100,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 350,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain mpu_3xxx_pwrdm = {
@@ -73,6 +79,12 @@  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_ON] = 0,
+	},
 };
 
 /*
@@ -99,6 +111,12 @@  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_ON] = 0,
+	},
 };
 
 static struct powerdomain core_3xxx_es3_1_pwrdm = {
@@ -118,6 +136,12 @@  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_ON] = 0,
+	},
 };
 
 static struct powerdomain dss_pwrdm = {
@@ -133,6 +157,12 @@  static struct powerdomain dss_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRDM_POWER_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 70,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 20,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 /*
@@ -154,6 +184,12 @@  static struct powerdomain sgx_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRDM_POWER_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 1000,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain cam_pwrdm = {
@@ -169,6 +205,12 @@  static struct powerdomain cam_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRDM_POWER_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 850,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 35,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain per_pwrdm = {
@@ -184,6 +226,12 @@  static struct powerdomain per_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRDM_POWER_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 200,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 110,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain emu_pwrdm = {
@@ -198,6 +246,12 @@  static struct powerdomain neon_pwrdm = {
 	.omap_chip	  = OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
 	.pwrsts		  = PWRSTS_OFF_RET_ON,
 	.pwrsts_logic_ret = PWRDM_POWER_RET,
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 200,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 35,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain usbhost_pwrdm = {
@@ -220,6 +274,12 @@  static struct powerdomain usbhost_pwrdm = {
 	.pwrsts_mem_on	  = {
 		[0] = PWRDM_POWER_ON,  /* MEMONSTATE */
 	},
+	.wakeup_lat = {
+		[PWRDM_FUNC_PWRST_OFF] = 800,
+		[PWRDM_FUNC_PWRST_OSWR] = UNSUP_STATE,
+		[PWRDM_FUNC_PWRST_CSWR] = 150,
+		[PWRDM_FUNC_PWRST_ON] = 0,
+	},
 };
 
 static struct powerdomain dpll1_pwrdm = {
diff --git a/arch/arm/plat-omap/include/plat/powerdomain.h b/arch/arm/plat-omap/include/plat/powerdomain.h
index fb6ec74..6ae5499 100644
--- a/arch/arm/plat-omap/include/plat/powerdomain.h
+++ b/arch/arm/plat-omap/include/plat/powerdomain.h
@@ -16,6 +16,9 @@ 
 
 #include <linux/types.h>
 #include <linux/list.h>
+#include <linux/plist.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
 
 #include <asm/atomic.h>
 
@@ -72,6 +75,16 @@ 
 /* XXX A completely arbitrary number. What is reasonable here? */
 #define PWRDM_TRANSITION_BAILOUT 100000
 
+/* 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_ON	0x3
+
+#define PWRDM_MAX_FUNC_PWRSTS	4
+
+#define UNSUP_STATE -1
+
 struct clockdomain;
 struct powerdomain;
 
@@ -92,6 +105,10 @@  struct powerdomain;
  * @state_counter:
  * @timer:
  * @state_timer:
+ * @wakeup_lat: Wakeup latencies for possible powerdomain power states
+ * @wakeuplat_lock: spinlock for plist
+ * @wakeuplat_dev_list: plist_head linking all devices placing constraint
+ * @wakeuplat_mutex: mutex to protect per powerdomain list ops
  */
 struct powerdomain {
 	const char *name;
@@ -114,8 +131,17 @@  struct powerdomain {
 	s64 timer;
 	s64 state_timer[PWRDM_MAX_PWRSTS];
 #endif
+	const u32 wakeup_lat[PWRDM_MAX_FUNC_PWRSTS];
+	spinlock_t wakeuplat_lock;
+	struct plist_head wakeuplat_dev_list;
+	struct mutex wakeuplat_mutex;
 };
 
+struct wakeuplat_dev_list {
+	struct device *dev;
+	unsigned long constraint_us;
+	struct plist_node node;
+};
 
 void pwrdm_init(struct powerdomain **pwrdm_list);
 
@@ -162,4 +188,10 @@  int pwrdm_clkdm_state_switch(struct clockdomain *clkdm);
 int pwrdm_pre_transition(void);
 int pwrdm_post_transition(void);
 
+int pwrdm_wakeuplat_set_constraint(struct powerdomain *pwrdm,
+				   struct device *dev, unsigned long t);
+int pwrdm_wakeuplat_release_constraint(struct powerdomain *pwrdm,
+				       struct device *dev);
+int pwrdm_wakeuplat_update_pwrst(struct powerdomain *pwrdm);
+
 #endif