diff mbox

[18/19] omap3630+: sr: add support for class 1.5

Message ID 1298116918-30744-19-git-send-email-nm@ti.com (mailing list archive)
State New, archived
Delegated to: Kevin Hilman
Headers show

Commit Message

Nishanth Menon Feb. 19, 2011, 12:01 p.m. UTC
None
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 1c0c2b0..1a82e6d 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -66,6 +66,7 @@  obj-$(CONFIG_ARCH_OMAP4)		+= pm44xx.o voltage.o pm_bus.o
 obj-$(CONFIG_PM_DEBUG)			+= pm-debug.o
 obj-$(CONFIG_OMAP_SMARTREFLEX)          += sr_device.o smartreflex.o
 obj-$(CONFIG_OMAP_SMARTREFLEX_CLASS3)	+= smartreflex-class3.o
+obj-$(CONFIG_OMAP_SMARTREFLEX_CLASS1P5)	+= smartreflex-class1p5.o
 
 AFLAGS_sleep24xx.o			:=-Wa,-march=armv6
 AFLAGS_sleep34xx.o			:=-Wa,-march=armv7-a
diff --git a/arch/arm/mach-omap2/smartreflex-class1p5.c b/arch/arm/mach-omap2/smartreflex-class1p5.c
new file mode 100644
index 0000000..832f10b
--- /dev/null
+++ b/arch/arm/mach-omap2/smartreflex-class1p5.c
@@ -0,0 +1,556 @@ 
+/*
+ * Smart reflex Class 1.5 specific implementations
+ *
+ * Copyright (C) 2010-2011 Texas Instruments, Inc.
+ * Nishanth Menon <nm@ti.com>
+ *
+ * Smart reflex class 1.5 is also called periodic SW Calibration
+ * Some of the highlights are as follows:
+ * – Host CPU triggers OPP calibration when transitioning to non calibrated
+ *   OPP
+ * – SR-AVS + VP modules are used to perform calibration
+ * – Once completed, the SmartReflex-AVS module can be disabled
+ * – Enables savings based on process, supply DC accuracy and aging
+ *
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/kobject.h>
+#include <linux/workqueue.h>
+#include <linux/opp.h>
+
+#include <plat/smartreflex.h>
+#include <plat/voltage.h>
+
+#define MAX_VDDS 3
+#define SR1P5_SAMPLING_DELAY_MS	1
+#define SR1P5_STABLE_SAMPLES	5
+#define SR1P5_MAX_TRIGGERS	5
+
+/*
+ * we expect events in 10uS, if we dont get 2wice times as much,
+ * we could kind of ignore this as a missed event.
+ */
+#define MAX_CHECK_VPTRANS_US	20
+
+/**
+ * struct sr_class1p5_work_data - data meant to be used by calibration work
+ * @work:	calibration work
+ * @voltdm:		voltage domain for which we are triggering
+ * @vdata:	voltage data we are calibrating
+ * @num_calib_triggers:	number of triggers from calibration loop
+ * @num_osc_samples:	number of samples collected by isr
+ * @work_active:	have we scheduled a work item?
+ */
+struct sr_class1p5_work_data {
+	struct delayed_work work;
+	struct voltagedomain *voltdm;
+	struct omap_volt_data *vdata;
+	u8 num_calib_triggers;
+	u8 num_osc_samples;
+	bool work_active;
+};
+
+#if CONFIG_OMAP_SR_CLASS1P5_RECALIBRATION_DELAY
+/* recal_work:	recalibration calibration work */
+static struct delayed_work recal_work;
+#endif
+
+/**
+ * struct sr_class1p5_data - private data for class 1p5
+ * @work_data:		work item data per voltage domain
+ */
+struct sr_class1p5_data {
+	struct sr_class1p5_work_data work_data[MAX_VDDS];
+};
+
+static void sr_class1p5_reset_calib(struct voltagedomain *voltdm, bool reset,
+				    bool recal);
+
+/* our instance of class 1p5 private data */
+static struct sr_class1p5_data class_1p5_data;
+
+static struct sr_class1p5_work_data *get_sr1p5_work(struct voltagedomain
+						    *voltdm)
+{
+	int idx;
+	for (idx = 0; idx < MAX_VDDS; idx++) {
+		if (class_1p5_data.work_data[idx].voltdm && !strcmp
+		    (class_1p5_data.work_data[idx].voltdm->name, voltdm->name))
+			return &class_1p5_data.work_data[idx];
+	}
+	return ERR_PTR(-ENODATA);
+}
+
+/**
+ * sr_class1p5_notify() - isr notifier for status events
+ * @voltdm:	voltage domain for which we were triggered
+ * @status:	notifier event to use
+ *
+ * This basically collects data for the work to use.
+ */
+static int sr_class1p5_notify(struct voltagedomain *voltdm, u32 status)
+{
+	struct sr_class1p5_work_data *work_data;
+	int idx = 0;
+	work_data = get_sr1p5_work(voltdm);
+
+	if (unlikely(!work_data)) {
+		pr_err("%s:%s no work data!!\n", __func__, voltdm->name);
+		return -EINVAL;
+	}
+
+	/* Wait for transdone so that we know the voltage to read */
+	do {
+		if (omap_vp_is_transdone(voltdm))
+			break;
+		idx++;
+		/* get some constant delay */
+		udelay(1);
+	} while (idx < MAX_CHECK_VPTRANS_US);
+
+	/*
+	 * If we timeout, we still read the data,
+	 * if we are oscillating+irq latencies are too high, we could
+	 * have scenarios where we miss transdone event. since
+	 * we waited long enough, it is still safe to read the voltage
+	 * as we would have waited long enough - still flag it..
+	 */
+	if (idx >= MAX_CHECK_VPTRANS_US)
+		pr_warning("%s: timed out waiting for transdone!!\n", __func__);
+
+	omap_vp_clear_transdone(voltdm);
+
+	idx = (work_data->num_osc_samples) % SR1P5_STABLE_SAMPLES;
+	work_data->num_osc_samples++;
+
+	return 0;
+}
+
+/**
+ * do_calibrate() - work which actually does the calibration
+ * @work: pointer to the work
+ *
+ * calibration routine uses the following logic:
+ * on the first trigger, we start the isr to collect sr voltages
+ * wait for stabilization delay (reschdule self instead of sleeping)
+ * after the delay, see if we collected any isr events
+ * if none, we have calibrated voltage.
+ * if there are any, we retry untill we giveup.
+ * on retry timeout, select a voltage to use as safe voltage.
+ */
+static void do_calibrate(struct work_struct *work)
+{
+	struct sr_class1p5_work_data *work_data =
+	    container_of(work, struct sr_class1p5_work_data, work.work);
+	unsigned long u_volt_safe = 0, u_volt_current = 0;
+	struct omap_volt_data *volt_data;
+	struct voltagedomain *voltdm;
+
+	if (unlikely(!work_data)) {
+		pr_err("%s: ooops.. null work_data?\n", __func__);
+		return;
+	}
+
+	/*
+	 * TODO:Handle the case where we might have just been scheduled AND
+	 * 1.5 disable was called. check and HOLD dvfs
+	 */
+
+	voltdm = work_data->voltdm;
+	/*
+	 * In the unlikely case that we did get through when unplanned,
+	 * flag and return.
+	 */
+	if (unlikely(!work_data->work_active)) {
+		pr_err("%s:%s unplanned work invocation!\n", __func__,
+		       voltdm->name);
+		/* TODO release the dvfs */
+		return;
+	}
+
+	work_data->num_calib_triggers++;
+	/* if we are triggered first time, we need to start isr to sample */
+	if (work_data->num_calib_triggers == 1)
+		goto start_sampling;
+
+	/* Stop isr from interrupting our measurements :) */
+	sr_notifier_control(voltdm, false);
+
+	volt_data = work_data->vdata;
+
+	/* if there are no samples captured.. SR is silent, aka stability! */
+	if (!work_data->num_osc_samples) {
+		u_volt_safe = omap_vp_get_curr_volt(voltdm);
+		u_volt_current = u_volt_safe;
+		goto done_calib;
+	}
+	if (work_data->num_calib_triggers == SR1P5_MAX_TRIGGERS) {
+		pr_warning("%s: %s recalib timeout!\n", __func__,
+			   work_data->voltdm->name);
+		goto oscillating_calib;
+	}
+
+	/* we have potential oscillations/first sample */
+start_sampling:
+	work_data->num_osc_samples = 0;
+	/* Clear pending events */
+	sr_notifier_control(voltdm, false);
+	/* Clear all transdones */
+	while (omap_vp_is_transdone(voltdm))
+		omap_vp_clear_transdone(voltdm);
+	/* trigger sampling */
+	sr_notifier_control(voltdm, true);
+	schedule_delayed_work(&work_data->work,
+			      msecs_to_jiffies(SR1P5_SAMPLING_DELAY_MS *
+					       SR1P5_STABLE_SAMPLES));
+	/* TODO: release dvfs */
+	return;
+
+oscillating_calib:
+	/* Use the nominal voltage as the safe voltage */
+	u_volt_safe = volt_data->volt_nominal;
+	/* pick up current voltage to switch if needed */
+	u_volt_current = omap_vp_get_curr_volt(voltdm);
+
+	/* Fall through to close up common stuff */
+done_calib:
+	omap_vp_disable(voltdm);
+	sr_disable(voltdm);
+
+	volt_data->volt_calibrated = u_volt_safe;
+	/* Setup my dynamic voltage for the next calibration for this opp */
+	volt_data->volt_dynamic_nominal = omap_get_dyn_nominal(volt_data);
+
+	/*
+	 * if the voltage we decided as safe is not the current voltage,
+	 * switch
+	 */
+	if (volt_data->volt_calibrated != u_volt_current) {
+		pr_debug("%s:%s reconfiguring to voltage %d\n",
+			 __func__, voltdm->name, volt_data->volt_calibrated);
+		omap_voltage_scale_vdd(voltdm, volt_data);
+	}
+
+	/*
+	 * TODO: Setup my wakeup voltage to allow immediate going to OFF and
+	 * on - Pending twl and voltage layer cleanups.
+	 * This is necessary, as this is not done as part of regular
+	 * Dvfs flow.
+	 * vc_setup_on_voltage(voltdm, volt_data->volt_calibrated);
+	 */
+	work_data->work_active = false;
+	/* TODO: release dvfs */
+}
+
+#if CONFIG_OMAP_SR_CLASS1P5_RECALIBRATION_DELAY
+/**
+ * do_recalibrate() - work which actually does the calibration
+ * @work: pointer to the work
+ *
+ * on a periodic basis, we come and reset our calibration setup
+ * so that a recalibration of the OPPs take place. This takes
+ * care of aging factor in the system.
+ */
+static void do_recalibrate(struct work_struct *work)
+{
+	struct voltagedomain *voltdm;
+	int idx;
+	static struct sr_class1p5_work_data *work_data;
+
+	for (idx = 0; idx < MAX_VDDS; idx++) {
+		work_data = &class_1p5_data.work_data[idx];
+		voltdm = work_data->voltdm;
+		if (voltdm) {
+			/* if sr is not enabled, we check later */
+			if (!is_sr_enabled(voltdm))
+				continue;
+			/* TODO: Pause the dvfs transitions */
+			/* if sr is not enabled, we check later */
+
+			/* Reset and force a recalibration for current opp */
+			sr_class1p5_reset_calib(voltdm, true, true);
+
+			/* TODO: unpause DVFS transitions */
+		}
+	}
+	/* We come back again after time the usual delay */
+	schedule_delayed_work(&recal_work,
+	      msecs_to_jiffies(CONFIG_OMAP_SR_CLASS1P5_RECALIBRATION_DELAY));
+}
+#endif /* CONFIG_OMAP_SR_CLASS1P5_RECALIBRATION_DELAY */
+
+/**
+ * sr_class1p5_enable() - class 1.5 mode of enable
+ * @voltdm:		voltage domain to enable SR for
+ * @volt_data:	voltdata to the voltage transition taking place
+ *
+ * when this gets called, we use the h/w loop to setup our voltages
+ * to an calibrated voltage, detect any oscillations, recover from the same
+ * and finally store the optimized voltage as the calibrated voltage in the
+ * system
+ */
+static int sr_class1p5_enable(struct voltagedomain *voltdm,
+			      struct omap_volt_data *volt_data)
+{
+	int r;
+	struct sr_class1p5_work_data *work_data;
+	/* if already calibrated, nothing to do here.. */
+	if (volt_data->volt_calibrated)
+		return 0;
+
+	work_data = get_sr1p5_work(voltdm);
+	if (unlikely(!work_data)) {
+		pr_err("%s: aieeee.. bad work data??\n", __func__);
+		return -EINVAL;
+	}
+
+	if (work_data->work_active)
+		return 0;
+
+	omap_vp_enable(voltdm);
+	r = sr_enable(voltdm, volt_data);
+	if (r) {
+		pr_err("%s: sr[%s] failed\n", __func__, voltdm->name);
+		omap_vp_disable(voltdm);
+		return r;
+	}
+	work_data->vdata = volt_data;
+	work_data->work_active = true;
+	work_data->num_calib_triggers = 0;
+	/* program the workqueue and leave it to calibrate offline.. */
+	schedule_delayed_work(&work_data->work,
+			      msecs_to_jiffies(SR1P5_SAMPLING_DELAY_MS *
+					       SR1P5_STABLE_SAMPLES));
+
+	return 0;
+}
+
+/**
+ * sr_class1p5_disable() - disable for class 1p5
+ * @voltdm: voltage domain for the sr which needs disabling
+ * @volt_data:	voltagedata to disable
+ * @is_volt_reset: reset the voltage?
+ *
+ * we dont do anything if the class 1p5 is being used. this is because we
+ * already disable sr at the end of calibration and no h/w loop is actually
+ * active when this is called.
+ */
+static int sr_class1p5_disable(struct voltagedomain *voltdm,
+			       struct omap_volt_data *volt_data,
+			       int is_volt_reset)
+{
+	struct sr_class1p5_work_data *work_data;
+
+	work_data = get_sr1p5_work(voltdm);
+	if (work_data->work_active) {
+		/* if volt reset and work is active, we dont allow this */
+		if (is_volt_reset)
+			return -EBUSY;
+		/* flag work is dead and remove the old work */
+		work_data->work_active = false;
+		cancel_delayed_work_sync(&work_data->work);
+		sr_notifier_control(voltdm, false);
+		omap_vp_disable(voltdm);
+		sr_disable(voltdm);
+	}
+
+	/* if already calibrated, nothin special to do here.. */
+	if (volt_data->volt_calibrated)
+		return 0;
+
+	if (is_volt_reset)
+		omap_voltage_reset(voltdm);
+	return 0;
+}
+
+/**
+ * sr_class1p5_configure() - configuration function
+ * @voldm:	configure for which voltage domain
+ *
+ * we dont do much here other than setup some registers for
+ * the sr module involved.
+ */
+static int sr_class1p5_configure(struct voltagedomain *voltdm)
+{
+	return sr_configure_errgen(voltdm);
+}
+
+/**
+ * sr_class1p5_reset_calib() - reset all calibrated voltages
+ * @srid:	srid to reset the calibration for
+ * @reset:	reset voltage before we recal?
+ * @recal:	should I recalibrate my current opp?
+ *
+ * if we call this, it means either periodic calibration trigger was
+ * fired(either from sysfs or other mechanisms) or we have disabled class 1p5,
+ * meaning we cant trust the calib voltages anymore, it is better to use
+ * nominal in the system
+ */
+static void sr_class1p5_reset_calib(struct voltagedomain *voltdm, bool reset,
+				    bool recal)
+{
+	struct sr_class1p5_work_data *work_data;
+
+	/* I dont need to go further if sr is not present */
+	if (!is_sr_enabled(voltdm))
+		return;
+
+	work_data = get_sr1p5_work(voltdm);
+
+	if (work_data->work_active)
+		sr_class1p5_disable(voltdm, work_data->vdata, 0);
+
+	omap_voltage_calib_reset(voltdm);
+
+	/*
+	 * I should now reset the voltages to my nominal to be safe
+	 */
+	if (reset)
+		omap_voltage_reset(voltdm);
+
+	/*
+	 * I should fire a recalibration for current opp if needed
+	 * Note: i have just reset my calibrated voltages, and if
+	 * i call sr_enable equivalent, I will cause a recalibration
+	 * loop, even though the function is called sr_enable.. we
+	 * are in class 1.5 ;)
+	 */
+	if (reset && recal)
+		sr_class1p5_enable(voltdm, work_data->vdata);
+}
+
+/**
+ * sr_class1p5_cinit() - class 1p5 init
+ * @voltdm:		sr voltage domain
+ * @class_priv_data:	private data for the class
+ *
+ * we do class specific initialization like creating sysfs/debugfs entries
+ * needed, spawning of a kthread if needed etc.
+ */
+static int sr_class1p5_cinit(struct voltagedomain *voltdm,
+			     void *class_priv_data)
+{
+	struct sr_class1p5_work_data *work_data;
+	int idx;
+
+	if (!class_priv_data) {
+		pr_err("%s: bad param? no priv data!\n", __func__);
+		return -EINVAL;
+	}
+
+	/* setup our work params */
+	work_data = get_sr1p5_work(voltdm);
+	if (!IS_ERR_OR_NULL(work_data)) {
+		pr_err("%s: ooopps.. class already initialized for %s! bug??\n",
+		       __func__, voltdm->name);
+		return -EINVAL;
+	}
+	work_data = NULL;
+	/* get the next spare work_data */
+	for (idx = 0; idx < MAX_VDDS; idx++) {
+		if (!class_1p5_data.work_data[idx].voltdm) {
+			work_data = &class_1p5_data.work_data[idx];
+			break;
+		}
+	}
+	if (!work_data) {
+		pr_err("%s: no more space for work data for domains!\n",
+			__func__);
+		return -ENOMEM;
+	}
+	work_data->voltdm = voltdm;
+	INIT_DELAYED_WORK_DEFERRABLE(&work_data->work, do_calibrate);
+	return 0;
+}
+
+/**
+ * sr_class1p5_cdeinit() - class 1p5 deinitialization
+ * @voltdm:	voltage domain for which to do this.
+ * @class_priv_data: class private data for deinitialiation
+ *
+ * currently only resets the calibrated voltage forcing dvfs voltages
+ * to be used in the system
+ */
+static int sr_class1p5_cdeinit(struct voltagedomain *voltdm,
+			       void *class_priv_data)
+{
+	struct sr_class1p5_work_data *work_data;
+
+	/* setup our work params */
+	work_data = get_sr1p5_work(voltdm);
+	if (IS_ERR_OR_NULL(work_data)) {
+		pr_err("%s: ooopps.. class not initialized for %s! bug??\n",
+		       __func__, voltdm->name);
+		return -EINVAL;
+	}
+
+	/*
+	 * we dont have SR periodic calib anymore.. so reset calibs
+	 * we are already protected by sr debugfs lock, so no lock needed
+	 * here.
+	 */
+	sr_class1p5_reset_calib(voltdm, true, false);
+
+	/* reset all data for this work data */
+	memset(work_data, 0, sizeof(*work_data));
+
+	return 0;
+}
+
+/* SR class1p5 structure */
+static struct omap_sr_class_data class1p5_data = {
+	.enable = sr_class1p5_enable,
+	.disable = sr_class1p5_disable,
+	.configure = sr_class1p5_configure,
+	.class_type = SR_CLASS1P5,
+	.class_init = sr_class1p5_cinit,
+	.class_deinit = sr_class1p5_cdeinit,
+	.notify = sr_class1p5_notify,
+	/*
+	 * trigger for bound - this tells VP that SR has a voltage
+	 * change. we should ensure transdone is set before reading
+	 * vp voltage.
+	 */
+	.notify_flags = SR_NOTIFY_MCUBOUND,
+	.class_priv_data = (void *)&class_1p5_data,
+};
+
+/**
+ * sr_class1p5_init() - register class 1p5 as default
+ *
+ * board files call this function to use class 1p5, we register with the
+ * smartreflex subsystem
+ */
+static int __init sr_class1p5_init(void)
+{
+	int r;
+
+	/* Enable this class only for OMAP3630 and OMAP4 */
+	if (!(cpu_is_omap3630() || cpu_is_omap44xx()))
+		return -EINVAL;
+
+	r = sr_register_class(&class1p5_data);
+	if (r) {
+		pr_err("SmartReflex class 1.5 driver: "
+		       "failed to register with %d\n", r);
+	} else {
+#if CONFIG_OMAP_SR_CLASS1P5_RECALIBRATION_DELAY
+		INIT_DELAYED_WORK_DEFERRABLE(&recal_work, do_recalibrate);
+		schedule_delayed_work(&recal_work, msecs_to_jiffies(
+				CONFIG_OMAP_SR_CLASS1P5_RECALIBRATION_DELAY));
+#endif
+		pr_info("SmartReflex class 1.5 driver: initialized (%dms)\n",
+			CONFIG_OMAP_SR_CLASS1P5_RECALIBRATION_DELAY);
+	}
+	return r;
+}
+late_initcall(sr_class1p5_init);
diff --git a/arch/arm/mach-omap2/smartreflex-class3.c b/arch/arm/mach-omap2/smartreflex-class3.c
index 7ac88da..5f7a33e 100644
--- a/arch/arm/mach-omap2/smartreflex-class3.c
+++ b/arch/arm/mach-omap2/smartreflex-class3.c
@@ -21,7 +21,9 @@  static int sr_class3_enable(struct voltagedomain *voltdm,
 	return sr_enable(voltdm, volt_data);
 }
 
-static int sr_class3_disable(struct voltagedomain *voltdm, int is_volt_reset)
+static int sr_class3_disable(struct voltagedomain *voltdm,
+				struct omap_volt_data *vdata,
+				int is_volt_reset)
 {
 	omap_vp_disable(voltdm);
 	sr_disable(voltdm);
diff --git a/arch/arm/mach-omap2/smartreflex.c b/arch/arm/mach-omap2/smartreflex.c
index 3a5f2f6..bb55b65 100644
--- a/arch/arm/mach-omap2/smartreflex.c
+++ b/arch/arm/mach-omap2/smartreflex.c
@@ -317,7 +317,9 @@  static void sr_stop_vddautocomp(struct omap_sr *sr)
 	}
 
 	if (sr->autocomp_active) {
-		sr_class->disable(sr->voltdm, 1);
+		sr_class->disable(sr->voltdm,
+				omap_voltage_get_nom_volt(sr->voltdm),
+				1);
 		if (sr_class->class_deinit &&
 		    sr_class->class_deinit(sr->voltdm,
 			    sr_class->class_priv_data)) {
@@ -471,6 +473,28 @@  static u32 sr_retrieve_nvalue(struct omap_sr *sr, u32 efuse_offs)
 /* Public Functions */
 
 /**
+ * is_sr_enabled() - is Smart reflex enabled for this domain?
+ * @voltdm: voltage domain to check
+ *
+ * Returns 0 if SR is enabled for this domain, else returns err
+ */
+bool is_sr_enabled(struct voltagedomain *voltdm)
+{
+	struct omap_sr *sr;
+	if (IS_ERR_OR_NULL(voltdm)) {
+		pr_warning("%s: invalid param voltdm\n", __func__);
+		return false;
+	}
+	sr = _sr_lookup(voltdm);
+	if (IS_ERR(sr)) {
+		pr_warning("%s: omap_sr struct for sr_%s not found\n",
+			__func__, voltdm->name);
+		return false;
+	}
+	return sr->autocomp_active;
+}
+
+/**
  * sr_configure_errgen() - Configures the smrtreflex to perform AVS using the
  *			 error generator module.
  * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
@@ -839,6 +863,7 @@  void omap_sr_enable(struct voltagedomain *voltdm,
  * omap_sr_disable() - API to disable SR without resetting the voltage
  *			processor voltage
  * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
+ * @volt_data:	Voltage data to go to
  *
  * This API is to be called from the kernel in order to disable
  * a particular smartreflex module. This API will in turn call
@@ -846,7 +871,8 @@  void omap_sr_enable(struct voltagedomain *voltdm,
  * the smartreflex class disable not to reset the VP voltage after
  * disabling smartreflex.
  */
-void omap_sr_disable(struct voltagedomain *voltdm)
+void omap_sr_disable(struct voltagedomain *voltdm,
+		struct omap_volt_data *vdata)
 {
 	struct omap_sr *sr = _sr_lookup(voltdm);
 
@@ -865,7 +891,7 @@  void omap_sr_disable(struct voltagedomain *voltdm)
 		return;
 	}
 
-	sr_class->disable(voltdm, 0);
+	sr_class->disable(voltdm, vdata, 0);
 }
 
 /**
@@ -898,7 +924,7 @@  void omap_sr_disable_reset_volt(struct voltagedomain *voltdm)
 		return;
 	}
 
-	sr_class->disable(voltdm, 1);
+	sr_class->disable(voltdm, omap_voltage_get_nom_volt(voltdm), 1);
 }
 
 /**
diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
index 77cb0cd..c451835 100644
--- a/arch/arm/mach-omap2/voltage.c
+++ b/arch/arm/mach-omap2/voltage.c
@@ -374,9 +374,45 @@  static int nom_volt_debug_get(void *data, u64 *val)
 	return 0;
 }
 
+static int dyn_volt_debug_get(void *data, u64 *val)
+{
+	struct omap_vdd_info *vdd = (struct omap_vdd_info *) data;
+	struct omap_volt_data *volt_data;
+
+	if (!vdd) {
+		pr_warning("Wrong paramater passed\n");
+		return -EINVAL;
+	}
+	volt_data = omap_voltage_get_nom_volt(&vdd->voltdm);
+
+	*val = volt_data->volt_dynamic_nominal;
+
+	return 0;
+}
+
+static int calib_volt_debug_get(void *data, u64 *val)
+{
+	struct omap_vdd_info *vdd = (struct omap_vdd_info *) data;
+	struct omap_volt_data *volt_data;
+
+	if (!vdd) {
+		pr_warning("Wrong paramater passed\n");
+		return -EINVAL;
+	}
+	volt_data = omap_voltage_get_nom_volt(&vdd->voltdm);
+
+	*val = volt_data->volt_calibrated;
+
+	return 0;
+}
+
 DEFINE_SIMPLE_ATTRIBUTE(vp_volt_debug_fops, vp_volt_debug_get, NULL, "%llu\n");
 DEFINE_SIMPLE_ATTRIBUTE(nom_volt_debug_fops, nom_volt_debug_get, NULL,
 								"%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(dyn_volt_debug_fops, dyn_volt_debug_get, NULL,
+								"%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(calib_volt_debug_fops, calib_volt_debug_get, NULL,
+								"%llu\n");
 static void vp_latch_vsel(struct omap_vdd_info *vdd)
 {
 	u32 vpconfig;
@@ -504,6 +540,12 @@  static void __init vdd_debugfs_init(struct omap_vdd_info *vdd)
 	(void) debugfs_create_file("curr_nominal_volt", S_IRUGO,
 				vdd->debug_dir, (void *) vdd,
 				&nom_volt_debug_fops);
+	(void) debugfs_create_file("curr_dyn_nominal_volt", S_IRUGO,
+				vdd->debug_dir, (void *) vdd,
+				&dyn_volt_debug_fops);
+	(void) debugfs_create_file("curr_calibrated_volt", S_IRUGO,
+				vdd->debug_dir, (void *) vdd,
+				&calib_volt_debug_fops);
 }
 
 /* Voltage scale and accessory APIs */
@@ -1132,6 +1174,33 @@  struct omap_volt_data *omap_voltage_get_nom_volt(struct voltagedomain *voltdm)
 }
 
 /**
+ * omap_voltage_calib_reset() - reset the calibrated voltage entries
+ * @voltdm: voltage domain to reset the entries for
+ *
+ * when the calibrated entries are no longer valid, this api allows
+ * the calibrated voltages to be reset.
+ */
+int omap_voltage_calib_reset(struct voltagedomain *voltdm)
+{
+	struct omap_vdd_info *vdd;
+	struct omap_volt_data *volt_data;
+
+	if (IS_ERR_OR_NULL(voltdm)) {
+		pr_warning("%s: VDD specified does not exist!\n", __func__);
+		return -EINVAL;
+	}
+
+	vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
+	volt_data = vdd->volt_data;
+	/* reset the calibrated voltages as 0 */
+	while (volt_data->volt_nominal) {
+		volt_data->volt_calibrated = 0;
+		volt_data++;
+	}
+	return 0;
+}
+
+/**
  * omap_vp_get_curr_volt() - API to get the current vp voltage.
  * @voltdm:	pointer to the VDD.
  *
diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index b6333ae..dba7939 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -67,6 +67,23 @@  config OMAP_SMARTREFLEX_CLASS3
 	  Class 3 implementation of Smartreflex employs continuous hardware
 	  voltage calibration.
 
+config OMAP_SMARTREFLEX_CLASS1P5
+	bool "Class 1.5 mode of Smartreflex Implementation"
+	depends on OMAP_SMARTREFLEX && TWL4030_CORE
+	help
+	  Say Y to enable Class 1.5 implementation of Smartreflex
+	  Class 1.5 implementation of Smartreflex employs software controlled
+	  hardware voltage calibration.
+
+config OMAP_SR_CLASS1P5_RECALIBRATION_DELAY
+	int "Class 1.5 mode recalibration recalibration delay(ms)"
+	depends on OMAP_SMARTREFLEX_CLASS1P5
+	default 86400000
+	help
+	  Setup the recalibration delay in milliseconds. Use 0 for never doing
+	  a recalibration. Defaults to recommended recalibration every 24hrs.
+	  If you do not understand this, use the default.
+
 config OMAP_RESET_CLOCKS
 	bool "Reset unused clocks during boot"
 	depends on ARCH_OMAP
diff --git a/arch/arm/plat-omap/include/plat/smartreflex.h b/arch/arm/plat-omap/include/plat/smartreflex.h
index 07f35b2..ee5c58f 100644
--- a/arch/arm/plat-omap/include/plat/smartreflex.h
+++ b/arch/arm/plat-omap/include/plat/smartreflex.h
@@ -167,6 +167,7 @@  struct omap_sr_pmic_data {
 #define SR_CLASS1	0x1
 #define SR_CLASS2	0x2
 #define SR_CLASS3	0x3
+#define SR_CLASS1P5	0x4
 
 /**
  * struct omap_sr_class_data - Smartreflex class driver info
@@ -187,7 +188,9 @@  struct omap_sr_pmic_data {
 struct omap_sr_class_data {
 	int (*enable)(struct voltagedomain *voltdm,
 			struct omap_volt_data *volt_data);
-	int (*disable)(struct voltagedomain *voltdm, int is_volt_reset);
+	int (*disable)(struct voltagedomain *voltdm,
+			struct omap_volt_data *volt_data,
+			int is_volt_reset);
 	int (*class_init)(struct voltagedomain *voltdm, void *class_priv_data);
 	int (*class_deinit)(struct voltagedomain *voltdm,
 			void *class_priv_data);
@@ -235,7 +238,8 @@  struct omap_sr_data {
 /* Smartreflex module enable/disable interface */
 void omap_sr_enable(struct voltagedomain *voltdm,
 			struct omap_volt_data *volt_data);
-void omap_sr_disable(struct voltagedomain *voltdm);
+void omap_sr_disable(struct voltagedomain *voltdm,
+			struct omap_volt_data *volt_data);
 void omap_sr_disable_reset_volt(struct voltagedomain *voltdm);
 
 /* API to register the pmic specific data with the smartreflex driver. */
@@ -250,6 +254,7 @@  int sr_configure_minmax(struct voltagedomain *voltdm);
 
 /* API to register the smartreflex class driver with the smartreflex driver */
 int sr_register_class(struct omap_sr_class_data *class_data);
+bool is_sr_enabled(struct voltagedomain *voltdm);
 #else
 static inline void omap_sr_enable(struct voltagedomain *voltdm) {}
 static inline void omap_sr_disable(struct voltagedomain *voltdm) {}
@@ -264,5 +269,9 @@  static inline void omap_sr_disable_reset_volt(
 		struct voltagedomain *voltdm) {}
 static inline void omap_sr_register_pmic(
 		struct omap_sr_pmic_data *pmic_data) {}
+static inline bool is_sr_enabled(struct voltagedomain *voltdm)
+{
+	return false;
+}
 #endif
 #endif
diff --git a/arch/arm/plat-omap/include/plat/voltage.h b/arch/arm/plat-omap/include/plat/voltage.h
index 332c581..54445f0 100644
--- a/arch/arm/plat-omap/include/plat/voltage.h
+++ b/arch/arm/plat-omap/include/plat/voltage.h
@@ -58,6 +58,8 @@ 
 #define OMAP4430_VDD_CORE_OPP50_UV		930000
 #define OMAP4430_VDD_CORE_OPP100_UV		1100000
 
+#define OMAP3PLUS_DYNAMIC_NOMINAL_MARGIN_UV	50000
+
 /**
  * struct voltagedomain - omap voltage domain global structure.
  * @name:	Name of the voltage domain which can be used as a unique
@@ -81,6 +83,8 @@  struct voltagedomain {
  */
 struct omap_volt_data {
 	u32	volt_nominal;
+	u32	volt_calibrated;
+	u32	volt_dynamic_nominal;
 	u32	sr_efuse_offs;
 	u8	sr_errminlimit;
 	u8	vp_errgain;
@@ -127,6 +131,7 @@  struct omap_volt_data *omap_voltage_get_nom_volt(struct voltagedomain *voltdm);
 bool omap_vp_is_transdone(struct voltagedomain *voltdm);
 bool omap_vp_clear_transdone(struct voltagedomain *voltdm);
 struct dentry *omap_voltage_get_dbgdir(struct voltagedomain *voltdm);
+int omap_voltage_calib_reset(struct voltagedomain *voltdm);
 #ifdef CONFIG_PM
 int omap_voltage_register_pmic(struct voltagedomain *voltdm,
 		struct omap_volt_pmic_info *pmic_info);
@@ -160,7 +165,23 @@  static inline unsigned long omap_get_operation_voltage(
 {
 	if (IS_ERR_OR_NULL(vdata))
 		return 0;
-	return vdata->volt_nominal;
+	return (vdata->volt_calibrated) ? vdata->volt_calibrated :
+		(vdata->volt_dynamic_nominal) ? vdata->volt_dynamic_nominal :
+			vdata->volt_nominal;
 }
 
+/* what is my dynamic nominal? */
+static inline unsigned long omap_get_dyn_nominal(struct omap_volt_data *vdata)
+{
+	if (IS_ERR_OR_NULL(vdata))
+		return 0;
+	if (vdata->volt_calibrated) {
+		unsigned long v = vdata->volt_calibrated +
+			OMAP3PLUS_DYNAMIC_NOMINAL_MARGIN_UV;
+		if (v > vdata->volt_nominal)
+			return vdata->volt_nominal;
+		return v;
+	}
+	return vdata->volt_nominal;
+}
 #endif