/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/bug.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/cpu.h>
#include <mach/rpm.h>
#include <mach/msm_iomap.h>
#include <asm/mach-types.h>
#include <linux/io.h>
#include <mach/socinfo.h>
#include "mpm.h"
#include "rpm_resources.h"
#include "spm.h"

/******************************************************************************
 * Debug Definitions
 *****************************************************************************/

enum {
	MSM_RPMRS_DEBUG_OUTPUT = BIT(0),
	MSM_RPMRS_DEBUG_BUFFER = BIT(1),
};

static int msm_rpmrs_debug_mask;
module_param_named(
	debug_mask, msm_rpmrs_debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP
);

static struct msm_rpmrs_level *msm_rpmrs_levels;
static int msm_rpmrs_level_count;

static bool msm_rpmrs_pxo_beyond_limits(struct msm_rpmrs_limits *limits);
static void msm_rpmrs_aggregate_pxo(struct msm_rpmrs_limits *limits);
static void msm_rpmrs_restore_pxo(void);
static bool msm_rpmrs_l2_cache_beyond_limits(struct msm_rpmrs_limits *limits);
static void msm_rpmrs_aggregate_l2_cache(struct msm_rpmrs_limits *limits);
static void msm_rpmrs_restore_l2_cache(void);
static bool msm_rpmrs_vdd_mem_beyond_limits(struct msm_rpmrs_limits *limits);
static void msm_rpmrs_aggregate_vdd_mem(struct msm_rpmrs_limits *limits);
static void msm_rpmrs_restore_vdd_mem(void);
static bool msm_rpmrs_vdd_dig_beyond_limits(struct msm_rpmrs_limits *limits);
static void msm_rpmrs_aggregate_vdd_dig(struct msm_rpmrs_limits *limits);
static void msm_rpmrs_restore_vdd_dig(void);

#ifdef CONFIG_MSM_L2_SPM
static  void *msm_rpmrs_l2_counter_addr;
static  int msm_rpmrs_l2_reset_count;
#define L2_PC_COUNTER_ADDR 0x660
#endif

#define MSM_RPMRS_MAX_RS_REGISTER_COUNT 2

struct msm_rpmrs_resource {
	struct msm_rpm_iv_pair rs[MSM_RPMRS_MAX_RS_REGISTER_COUNT];
	uint32_t size;
	char *name;

	uint32_t enable_low_power;

	bool (*beyond_limits)(struct msm_rpmrs_limits *limits);
	void (*aggregate)(struct msm_rpmrs_limits *limits);
	void (*restore)(void);
};

static struct msm_rpmrs_resource msm_rpmrs_pxo = {
	.rs[0].id = MSM_RPMRS_ID_PXO_CLK,
	.size = 1,
	.name = "pxo",
	.beyond_limits = msm_rpmrs_pxo_beyond_limits,
	.aggregate = msm_rpmrs_aggregate_pxo,
	.restore = msm_rpmrs_restore_pxo,
};

static struct msm_rpmrs_resource msm_rpmrs_l2_cache = {
	.rs[0].id = MSM_RPMRS_ID_APPS_L2_CACHE_CTL,
	.size = 1,
	.name = "L2_cache",
	.beyond_limits = msm_rpmrs_l2_cache_beyond_limits,
	.aggregate = msm_rpmrs_aggregate_l2_cache,
	.restore = msm_rpmrs_restore_l2_cache,
};

static struct msm_rpmrs_resource msm_rpmrs_vdd_mem = {
	.rs[0].id = MSM_RPMRS_ID_VDD_MEM_0,
	.rs[1].id = MSM_RPMRS_ID_VDD_MEM_1,
	.size = 2,
	.name = "vdd_mem",
	.beyond_limits = msm_rpmrs_vdd_mem_beyond_limits,
	.aggregate = msm_rpmrs_aggregate_vdd_mem,
	.restore = msm_rpmrs_restore_vdd_mem,
};

static struct msm_rpmrs_resource msm_rpmrs_vdd_dig = {
	.rs[0].id = MSM_RPMRS_ID_VDD_DIG_0,
	.rs[1].id = MSM_RPMRS_ID_VDD_DIG_1,
	.size = 2,
	.name = "vdd_dig",
	.beyond_limits = msm_rpmrs_vdd_dig_beyond_limits,
	.aggregate = msm_rpmrs_aggregate_vdd_dig,
	.restore = msm_rpmrs_restore_vdd_dig,
};

static struct msm_rpmrs_resource msm_rpmrs_rpm_cpu = {
	.rs[0].id = MSM_RPMRS_ID_RPM_CTL,
	.size = 1,
	.name = "rpm_cpu",
	.beyond_limits = NULL,
	.aggregate = NULL,
	.restore = NULL,
};

static struct msm_rpmrs_resource *msm_rpmrs_resources[] = {
	&msm_rpmrs_pxo,
	&msm_rpmrs_l2_cache,
	&msm_rpmrs_vdd_mem,
	&msm_rpmrs_vdd_dig,
	&msm_rpmrs_rpm_cpu,
};

static uint32_t msm_rpmrs_buffer[MSM_RPM_ID_LAST + 1];
static DECLARE_BITMAP(msm_rpmrs_buffered, MSM_RPM_ID_LAST + 1);
static DECLARE_BITMAP(msm_rpmrs_listed, MSM_RPM_ID_LAST + 1);
static DEFINE_SPINLOCK(msm_rpmrs_lock);

#define MSM_RPMRS_VDD_MASK  0xfff
#define MSM_RPMRS_VDD(v)  ((v) & (MSM_RPMRS_VDD_MASK))

/******************************************************************************
 * Attribute Definitions
 *****************************************************************************/

struct msm_rpmrs_kboj_attribute {
	struct msm_rpmrs_resource *rs;
	struct kobj_attribute ka;
};

#define GET_RS_FROM_ATTR(attr) \
	(container_of(attr, struct msm_rpmrs_kboj_attribute, ka)->rs)

struct msm_rpmrs_resource_sysfs {
	struct attribute_group attr_group;
	struct attribute *attrs[2];
	struct msm_rpmrs_kboj_attribute kas;
};

/******************************************************************************
 * Resource Specific Functions
 *****************************************************************************/

static void msm_rpmrs_aggregate_sclk(uint32_t sclk_count)
{
	msm_rpmrs_buffer[MSM_RPM_ID_TRIGGER_TIMED_TO] = 0;
	set_bit(MSM_RPM_ID_TRIGGER_TIMED_TO, msm_rpmrs_buffered);
	msm_rpmrs_buffer[MSM_RPM_ID_TRIGGER_TIMED_SCLK_COUNT] = sclk_count;
	set_bit(MSM_RPM_ID_TRIGGER_TIMED_SCLK_COUNT, msm_rpmrs_buffered);
}

static void msm_rpmrs_restore_sclk(void)
{
	clear_bit(MSM_RPM_ID_TRIGGER_TIMED_SCLK_COUNT, msm_rpmrs_buffered);
	msm_rpmrs_buffer[MSM_RPM_ID_TRIGGER_TIMED_SCLK_COUNT] = 0;
	clear_bit(MSM_RPM_ID_TRIGGER_TIMED_TO, msm_rpmrs_buffered);
	msm_rpmrs_buffer[MSM_RPM_ID_TRIGGER_TIMED_TO] = 0;
}

static bool msm_rpmrs_pxo_beyond_limits(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_pxo;
	uint32_t pxo;

	if (rs->enable_low_power && test_bit(rs->rs[0].id, msm_rpmrs_buffered))
		pxo = msm_rpmrs_buffer[rs->rs[0].id];
	else
		pxo = MSM_RPMRS_PXO_ON;

	return pxo > limits->pxo;
}

static void msm_rpmrs_aggregate_pxo(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_pxo;
	uint32_t *buf = &msm_rpmrs_buffer[rs->rs[0].id];

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered)) {
		rs->rs[0].value = *buf;
		if (limits->pxo > *buf)
			*buf = limits->pxo;
		if (MSM_RPMRS_DEBUG_OUTPUT & msm_rpmrs_debug_mask)
			pr_info("%s: %d (0x%x)\n", __func__, *buf, *buf);
	}
}

static void msm_rpmrs_restore_pxo(void)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_pxo;

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered))
		msm_rpmrs_buffer[rs->rs[0].id] = rs->rs[0].value;
}

static bool msm_rpmrs_l2_cache_beyond_limits(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_l2_cache;
	uint32_t l2_cache;

	if (rs->enable_low_power && test_bit(rs->rs[0].id, msm_rpmrs_buffered))
		l2_cache = msm_rpmrs_buffer[rs->rs[0].id];
	else
		l2_cache = MSM_RPMRS_L2_CACHE_ACTIVE;

	return l2_cache > limits->l2_cache;
}

static void msm_rpmrs_aggregate_l2_cache(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_l2_cache;
	uint32_t *buf = &msm_rpmrs_buffer[rs->rs[0].id];

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered)) {
		rs->rs[0].value = *buf;
		if (limits->l2_cache > *buf)
			*buf = limits->l2_cache;

		if (MSM_RPMRS_DEBUG_OUTPUT & msm_rpmrs_debug_mask)
			pr_info("%s: %d (0x%x)\n", __func__, *buf, *buf);
	}
}

#ifdef CONFIG_MSM_L2_SPM
static bool msm_spm_l2_cache_beyond_limits(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_l2_cache;
	uint32_t l2_cache = rs->rs[0].value;

	if (!rs->enable_low_power)
		l2_cache = MSM_RPMRS_L2_CACHE_ACTIVE;

	return l2_cache > limits->l2_cache;
}
#endif

static void msm_rpmrs_restore_l2_cache(void)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_l2_cache;

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered))
		msm_rpmrs_buffer[rs->rs[0].id] = rs->rs[0].value;
}

static bool msm_rpmrs_vdd_mem_beyond_limits(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_vdd_mem;
	uint32_t vdd_mem;

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered)) {
		uint32_t buffered_value = msm_rpmrs_buffer[rs->rs[0].id];

		if (rs->enable_low_power == 0)
			vdd_mem = MSM_RPMRS_VDD_MEM_ACTIVE;
		else if (rs->enable_low_power == 1)
			vdd_mem = MSM_RPMRS_VDD_MEM_RET_HIGH;
		else
			vdd_mem = MSM_RPMRS_VDD_MEM_RET_LOW;

		if (MSM_RPMRS_VDD(buffered_value) > MSM_RPMRS_VDD(vdd_mem))
			vdd_mem = buffered_value;
	} else {
		vdd_mem = MSM_RPMRS_VDD_MEM_ACTIVE;
	}

	return MSM_RPMRS_VDD(vdd_mem) >=
				MSM_RPMRS_VDD(limits->vdd_mem_upper_bound);
}

static void msm_rpmrs_aggregate_vdd_mem(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_vdd_mem;
	uint32_t *buf = &msm_rpmrs_buffer[rs->rs[0].id];

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered)) {
		rs->rs[0].value = *buf;
		if (MSM_RPMRS_VDD(limits->vdd_mem) > MSM_RPMRS_VDD(*buf)) {
			*buf &= ~MSM_RPMRS_VDD_MASK;
			*buf |= MSM_RPMRS_VDD(limits->vdd_mem);
		}

		if (MSM_RPMRS_DEBUG_OUTPUT & msm_rpmrs_debug_mask)
			pr_info("%s: vdd %d (0x%x)\n", __func__,
				MSM_RPMRS_VDD(*buf), MSM_RPMRS_VDD(*buf));
	}
}

static void msm_rpmrs_restore_vdd_mem(void)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_vdd_mem;

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered))
		msm_rpmrs_buffer[rs->rs[0].id] = rs->rs[0].value;
}

static bool msm_rpmrs_vdd_dig_beyond_limits(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_vdd_dig;
	uint32_t vdd_dig;

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered)) {
		uint32_t buffered_value = msm_rpmrs_buffer[rs->rs[0].id];

		if (rs->enable_low_power == 0)
			vdd_dig = MSM_RPMRS_VDD_DIG_ACTIVE;
		else if (rs->enable_low_power == 1)
			vdd_dig = MSM_RPMRS_VDD_DIG_RET_HIGH;
		else
			vdd_dig = MSM_RPMRS_VDD_DIG_RET_LOW;

		if (MSM_RPMRS_VDD(buffered_value) > MSM_RPMRS_VDD(vdd_dig))
			vdd_dig = buffered_value;
	} else {
		vdd_dig = MSM_RPMRS_VDD_DIG_ACTIVE;
	}

	return MSM_RPMRS_VDD(vdd_dig) >=
				MSM_RPMRS_VDD(limits->vdd_dig_upper_bound);
}

static void msm_rpmrs_aggregate_vdd_dig(struct msm_rpmrs_limits *limits)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_vdd_dig;
	uint32_t *buf = &msm_rpmrs_buffer[rs->rs[0].id];

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered)) {
		rs->rs[0].value = *buf;
		if (MSM_RPMRS_VDD(limits->vdd_dig) > MSM_RPMRS_VDD(*buf)) {
			*buf &= ~MSM_RPMRS_VDD_MASK;
			*buf |= MSM_RPMRS_VDD(limits->vdd_dig);
		}


		if (MSM_RPMRS_DEBUG_OUTPUT & msm_rpmrs_debug_mask)
			pr_info("%s: vdd %d (0x%x)\n", __func__,
				MSM_RPMRS_VDD(*buf), MSM_RPMRS_VDD(*buf));
	}
}

static void msm_rpmrs_restore_vdd_dig(void)
{
	struct msm_rpmrs_resource *rs = &msm_rpmrs_vdd_dig;

	if (test_bit(rs->rs[0].id, msm_rpmrs_buffered))
		msm_rpmrs_buffer[rs->rs[0].id] = rs->rs[0].value;
}

/******************************************************************************
 * Buffering Functions
 *****************************************************************************/

static bool msm_rpmrs_irqs_detectable(struct msm_rpmrs_limits *limits,
		bool irqs_detect, bool gpio_detect)
{

	if (limits->vdd_dig <= MSM_RPMRS_VDD_DIG_RET_HIGH)
		return irqs_detect;

	if (limits->pxo == MSM_RPMRS_PXO_OFF)
		return gpio_detect;

	return true;
}

static bool msm_rpmrs_use_mpm(struct msm_rpmrs_limits *limits)
{
	return (limits->pxo == MSM_RPMRS_PXO_OFF) ||
		(limits->vdd_dig <= MSM_RPMRS_VDD_DIG_RET_HIGH);
}

static void msm_rpmrs_update_levels(void)
{
	int i, k;

	for (i = 0; i < msm_rpmrs_level_count; i++) {
		struct msm_rpmrs_level *level = &msm_rpmrs_levels[i];

		if (level->sleep_mode != MSM_PM_SLEEP_MODE_POWER_COLLAPSE)
			continue;

		level->available = true;

		for (k = 0; k < ARRAY_SIZE(msm_rpmrs_resources); k++) {
			struct msm_rpmrs_resource *rs = msm_rpmrs_resources[k];

			if (rs->beyond_limits &&
					rs->beyond_limits(&level->rs_limits)) {
				level->available = false;
				break;
			}
		}
	}
}

/*
 * Return value:
 *   0: no entries in <req> is on our resource list
 *   1: one or more entries in <req> is on our resource list
 *   -EINVAL: invalid id in <req> array
 */
static int msm_rpmrs_buffer_request(struct msm_rpm_iv_pair *req, int count)
{
	bool listed;
	int i;

	for (i = 0; i < count; i++)
		if (req[i].id > MSM_RPM_ID_LAST)
			return -EINVAL;

	for (i = 0, listed = false; i < count; i++) {
		msm_rpmrs_buffer[req[i].id] = req[i].value;
		set_bit(req[i].id, msm_rpmrs_buffered);

		if (MSM_RPMRS_DEBUG_BUFFER & msm_rpmrs_debug_mask)
			pr_info("%s: reg %d: 0x%x\n",
				__func__, req[i].id, req[i].value);

		if (listed)
			continue;

		if (test_bit(req[i].id, msm_rpmrs_listed))
			listed = true;
	}

	return listed ? 1 : 0;
}

/*
 * Return value:
 *   0: no entries in <req> is on our resource list
 *   1: one or more entries in <req> is on our resource list
 *   -EINVAL: invalid id in <req> array
 */
static int msm_rpmrs_clear_buffer(struct msm_rpm_iv_pair *req, int count)
{
	bool listed;
	int i;

	for (i = 0; i < count; i++)
		if (req[i].id > MSM_RPM_ID_LAST)
			return -EINVAL;

	for (i = 0, listed = false; i < count; i++) {
		msm_rpmrs_buffer[req[i].id] = 0;
		clear_bit(req[i].id, msm_rpmrs_buffered);

		if (MSM_RPMRS_DEBUG_BUFFER & msm_rpmrs_debug_mask)
			pr_info("%s: reg %d\n", __func__, req[i].id);

		if (listed)
			continue;

		if (test_bit(req[i].id, msm_rpmrs_listed))
			listed = true;
	}

	return listed ? 1 : 0;
}

#ifdef CONFIG_MSM_L2_SPM
static int msm_rpmrs_flush_L2(struct msm_rpmrs_limits *limits, int notify_rpm)
{
	int rc = 0;
	int lpm;

	switch (limits->l2_cache) {
	case MSM_RPMRS_L2_CACHE_HSFS_OPEN:
		lpm = MSM_SPM_L2_MODE_POWER_COLLAPSE;
		/* Increment the counter for TZ to init L2  on warmboot */
		/* Barrier in msm_spm_l2_set_low_power_mode */
		BUG_ON(!msm_rpmrs_l2_counter_addr);
		writel_relaxed(++msm_rpmrs_l2_reset_count,
				msm_rpmrs_l2_counter_addr);
		break;
	case MSM_RPMRS_L2_CACHE_GDHS:
		lpm = MSM_SPM_L2_MODE_GDHS;
		break;
	case MSM_RPMRS_L2_CACHE_RETENTION:
		lpm = MSM_SPM_L2_MODE_RETENTION;
		break;
	default:
	case MSM_RPMRS_L2_CACHE_ACTIVE:
		lpm = MSM_SPM_L2_MODE_DISABLED;
		break;
	}

	rc = msm_spm_l2_set_low_power_mode(lpm, notify_rpm);
	if (MSM_RPMRS_DEBUG_BUFFER & msm_rpmrs_debug_mask)
		pr_info("%s: Requesting low power mode %d returned %d\n",
				__func__, lpm, rc);

	return rc;
}
#else
static int msm_rpmrs_flush_L2(struct msm_rpmrs_limits *limits, int notify_rpm)
{
	return 0;
}
#endif

static int msm_rpmrs_flush_buffer(
	uint32_t sclk_count, struct msm_rpmrs_limits *limits, int from_idle)
{
	struct msm_rpm_iv_pair *req;
	int count;
	int rc;
	int i;

	msm_rpmrs_aggregate_sclk(sclk_count);
	for (i = 0; i < ARRAY_SIZE(msm_rpmrs_resources); i++) {
		if (msm_rpmrs_resources[i]->aggregate)
			msm_rpmrs_resources[i]->aggregate(limits);
	}

	count = bitmap_weight(msm_rpmrs_buffered, MSM_RPM_ID_LAST + 1);

	req = kmalloc(sizeof(*req) * count, GFP_ATOMIC);
	if (!req) {
		rc = -ENOMEM;
		goto flush_buffer_restore;
	}

	count = 0;
	i = find_first_bit(msm_rpmrs_buffered, MSM_RPM_ID_LAST + 1);

	while (i < MSM_RPM_ID_LAST + 1) {
		if (MSM_RPMRS_DEBUG_OUTPUT & msm_rpmrs_debug_mask)
			pr_info("%s: reg %d: 0x%x\n",
				__func__, i, msm_rpmrs_buffer[i]);

		req[count].id = i;
		req[count].value = msm_rpmrs_buffer[i];
		count++;

		i = find_next_bit(msm_rpmrs_buffered, MSM_RPM_ID_LAST+1, i+1);
	}

	rc = msm_rpm_set_noirq(MSM_RPM_CTX_SET_SLEEP, req, count);
	kfree(req);

	if (rc)
		goto flush_buffer_restore;

	bitmap_and(msm_rpmrs_buffered,
		msm_rpmrs_buffered, msm_rpmrs_listed, MSM_RPM_ID_LAST + 1);

flush_buffer_restore:
	for (i = 0; i < ARRAY_SIZE(msm_rpmrs_resources); i++) {
		if (msm_rpmrs_resources[i]->restore)
			msm_rpmrs_resources[i]->restore();
	}
	msm_rpmrs_restore_sclk();

	if (rc)
		pr_err("%s: failed: %d\n", __func__, rc);
	return rc;
}

static int msm_rpmrs_set_common(
	int ctx, struct msm_rpm_iv_pair *req, int count, bool noirq)
{
	if (ctx == MSM_RPM_CTX_SET_SLEEP) {
		unsigned long flags;
		int rc;

		spin_lock_irqsave(&msm_rpmrs_lock, flags);
		rc = msm_rpmrs_buffer_request(req, count);
		if (rc > 0) {
			msm_rpmrs_update_levels();
			rc = 0;
		}
		spin_unlock_irqrestore(&msm_rpmrs_lock, flags);

		return rc;
	}

	if (noirq)
		return msm_rpm_set_noirq(ctx, req, count);
	else
		return msm_rpm_set(ctx, req, count);
}

static int msm_rpmrs_clear_common(
	int ctx, struct msm_rpm_iv_pair *req, int count, bool noirq)
{
	if (ctx == MSM_RPM_CTX_SET_SLEEP) {
		unsigned long flags;
		int rc;

		spin_lock_irqsave(&msm_rpmrs_lock, flags);
		rc = msm_rpmrs_clear_buffer(req, count);
		if (rc > 0) {
			msm_rpmrs_update_levels();
			rc = 0;
		}
		spin_unlock_irqrestore(&msm_rpmrs_lock, flags);

		if (rc < 0)
			return rc;
	}

	if (noirq)
		return msm_rpm_clear_noirq(ctx, req, count);
	else
		return msm_rpm_clear(ctx, req, count);
}

/******************************************************************************
 * Attribute Functions
 *****************************************************************************/

static ssize_t msm_rpmrs_resource_attr_show(
	struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
	struct kernel_param kp;
	unsigned long flags;
	unsigned int temp;
	int rc;

	spin_lock_irqsave(&msm_rpmrs_lock, flags);
	temp = GET_RS_FROM_ATTR(attr)->enable_low_power;
	spin_unlock_irqrestore(&msm_rpmrs_lock, flags);

	kp.arg = &temp;
	rc = param_get_uint(buf, &kp);

	if (rc > 0) {
		strcat(buf, "\n");
		rc++;
	}

	return rc;
}

static ssize_t msm_rpmrs_resource_attr_store(struct kobject *kobj,
	struct kobj_attribute *attr, const char *buf, size_t count)
{
	struct kernel_param kp;
	unsigned long flags;
	unsigned int temp;
	int rc;

	kp.arg = &temp;
	rc = param_set_uint(buf, &kp);
	if (rc)
		return rc;

	spin_lock_irqsave(&msm_rpmrs_lock, flags);
	GET_RS_FROM_ATTR(attr)->enable_low_power = temp;

	/* special case active-set signal for MSM_RPMRS_ID_RPM_CTL */
	if (GET_RS_FROM_ATTR(attr)->rs[0].id == MSM_RPMRS_ID_RPM_CTL) {
		struct msm_rpm_iv_pair req;
		req.id = MSM_RPMRS_ID_RPM_CTL;
		req.value = GET_RS_FROM_ATTR(attr)->enable_low_power ? 0 : 1;

		rc = msm_rpm_set_noirq(MSM_RPM_CTX_SET_0, &req, 1);
		if (rc) {
			pr_err("%s: failed to request RPM_CTL to %d: %d\n",
				__func__, req.value, rc);
		}
	}

	msm_rpmrs_update_levels();
	spin_unlock_irqrestore(&msm_rpmrs_lock, flags);

	return count;
}

static int __init msm_rpmrs_resource_sysfs_add(void)
{
	struct kobject *module_kobj;
	struct kobject *low_power_kboj;
	struct msm_rpmrs_resource_sysfs *rs;
	int i;
	int rc;

	module_kobj = kset_find_obj(module_kset, KBUILD_MODNAME);
	if (!module_kobj) {
		pr_err("%s: cannot find kobject for module %s\n",
			__func__, KBUILD_MODNAME);
		rc = -ENOENT;
		goto resource_sysfs_add_exit;
	}

	low_power_kboj = kobject_create_and_add(
				"enable_low_power", module_kobj);
	if (!low_power_kboj) {
		pr_err("%s: cannot create kobject\n", __func__);
		rc = -ENOMEM;
		goto resource_sysfs_add_exit;
	}

	for (i = 0; i < ARRAY_SIZE(msm_rpmrs_resources); i++) {
		rs = kzalloc(sizeof(*rs), GFP_KERNEL);
		if (!rs) {
			pr_err("%s: cannot allocate memory for attributes\n",
				__func__);
			rc = -ENOMEM;
			goto resource_sysfs_add_exit;
		}

		rs->kas.rs = msm_rpmrs_resources[i];
		rs->kas.ka.attr.name = msm_rpmrs_resources[i]->name;
		rs->kas.ka.attr.mode = 0644;
		rs->kas.ka.show = msm_rpmrs_resource_attr_show;
		rs->kas.ka.store = msm_rpmrs_resource_attr_store;

		rs->attrs[0] = &rs->kas.ka.attr;
		rs->attrs[1] = NULL;
		rs->attr_group.attrs = rs->attrs;

		rc = sysfs_create_group(low_power_kboj, &rs->attr_group);
		if (rc) {
			pr_err("%s: cannot create kobject attribute group\n",
				__func__);
			goto resource_sysfs_add_exit;
		}
	}

	rc = 0;

resource_sysfs_add_exit:
	return rc;
}

/******************************************************************************
 * Public Functions
 *****************************************************************************/

int msm_rpmrs_set(int ctx, struct msm_rpm_iv_pair *req, int count)
{
	return msm_rpmrs_set_common(ctx, req, count, false);
}

int msm_rpmrs_set_noirq(int ctx, struct msm_rpm_iv_pair *req, int count)
{
	WARN(!irqs_disabled(), "msm_rpmrs_set_noirq can only be called "
		"safely when local irqs are disabled.  Consider using "
		"msm_rpmrs_set or msm_rpmrs_set_nosleep instead.");
	return msm_rpmrs_set_common(ctx, req, count, true);
}

int msm_rpmrs_clear(int ctx, struct msm_rpm_iv_pair *req, int count)
{
	return msm_rpmrs_clear_common(ctx, req, count, false);
}

int msm_rpmrs_clear_noirq(int ctx, struct msm_rpm_iv_pair *req, int count)
{
	WARN(!irqs_disabled(), "msm_rpmrs_clear_noirq can only be called "
		"safely when local irqs are disabled.  Consider using "
		"msm_rpmrs_clear or msm_rpmrs_clear_nosleep instead.");
	return msm_rpmrs_clear_common(ctx, req, count, true);
}

void msm_rpmrs_show_resources(void)
{
	struct msm_rpmrs_resource *rs;
	unsigned long flags;
	int i;

	spin_lock_irqsave(&msm_rpmrs_lock, flags);
	for (i = 0; i < ARRAY_SIZE(msm_rpmrs_resources); i++) {
		rs = msm_rpmrs_resources[i];
		if (rs->rs[0].id < MSM_RPM_ID_LAST + 1)
			pr_info("%s: resource %s: buffered %d, value 0x%x\n",
				__func__, rs->name,
				test_bit(rs->rs[0].id, msm_rpmrs_buffered),
				msm_rpmrs_buffer[rs->rs[0].id]);
		else
			pr_info("%s: resource %s: value %d\n",
				__func__, rs->name, rs->rs[0].value);
	}
	spin_unlock_irqrestore(&msm_rpmrs_lock, flags);
}

struct msm_rpmrs_limits *msm_rpmrs_lowest_limits(
	bool from_idle, enum msm_pm_sleep_mode sleep_mode, uint32_t latency_us,
	uint32_t sleep_us)
{
	unsigned int cpu = smp_processor_id();
	struct msm_rpmrs_level *best_level = NULL;
	bool irqs_detectable = false;
	bool gpio_detectable = false;
	int i;

	if (sleep_mode == MSM_PM_SLEEP_MODE_POWER_COLLAPSE) {
		irqs_detectable = msm_mpm_irqs_detectable(from_idle);
		gpio_detectable = msm_mpm_gpio_irqs_detectable(from_idle);
	}

	for (i = 0; i < msm_rpmrs_level_count; i++) {
		struct msm_rpmrs_level *level = &msm_rpmrs_levels[i];
		uint32_t power;

		if (!level->available)
			continue;

		if (sleep_mode != level->sleep_mode)
			continue;

		if (latency_us < level->latency_us)
			continue;

		if (!msm_rpmrs_irqs_detectable(&level->rs_limits,
					irqs_detectable, gpio_detectable))
			continue;

		if (sleep_us <= 1) {
			power = level->energy_overhead;
		} else if (sleep_us <= level->time_overhead_us) {
			power = level->energy_overhead / sleep_us;
		} else if ((sleep_us >> 10) > level->time_overhead_us) {
			power = level->steady_state_power;
		} else {
			power = (sleep_us - level->time_overhead_us);
			power *= level->steady_state_power;
			power /= sleep_us;
			power += level->energy_overhead / sleep_us;
		}

		if (!best_level ||
				best_level->rs_limits.power[cpu] >= power) {
			level->rs_limits.latency_us[cpu] = level->latency_us;
			level->rs_limits.power[cpu] = power;
			best_level = level;
		}
	}

	return best_level ? &best_level->rs_limits : NULL;
}

int msm_rpmrs_enter_sleep(uint32_t sclk_count, struct msm_rpmrs_limits *limits,
		bool from_idle, bool notify_rpm)
{
	int rc = 0;

	rc = msm_rpmrs_flush_L2(limits, notify_rpm);
	if (rc)
		return rc;

	if (notify_rpm) {
		rc = msm_rpmrs_flush_buffer(sclk_count, limits, from_idle);
		if (rc)
			return rc;

		if (msm_rpmrs_use_mpm(limits))
			msm_mpm_enter_sleep(from_idle);
	}

	return rc;
}

void msm_rpmrs_exit_sleep(struct msm_rpmrs_limits *limits,
		bool from_idle, bool notify_rpm)
{

	/* Disable L2 for now, we dont want L2 to do retention by default */
	msm_spm_l2_set_low_power_mode(MSM_SPM_MODE_DISABLED, notify_rpm);

	if (msm_rpmrs_use_mpm(limits))
		msm_mpm_exit_sleep(from_idle);
}

#ifdef CONFIG_MSM_L2_SPM
static int rpmrs_cpu_callback(struct notifier_block *nfb,
		unsigned long action, void *hcpu)
{
	switch (action) {
	case CPU_ONLINE_FROZEN:
	case CPU_ONLINE:
		if (num_online_cpus() > 1)
			msm_rpmrs_l2_cache.rs[0].value =
				MSM_RPMRS_L2_CACHE_ACTIVE;
		break;
	case CPU_DEAD_FROZEN:
	case CPU_DEAD:
		if (num_online_cpus() == 1)
			msm_rpmrs_l2_cache.rs[0].value =
				MSM_RPMRS_L2_CACHE_HSFS_OPEN;
		break;
	}

	msm_rpmrs_update_levels();
	return NOTIFY_OK;
}

static struct notifier_block __refdata rpmrs_cpu_notifier = {
	.notifier_call = rpmrs_cpu_callback,
};
#endif

int __init msm_rpmrs_levels_init(struct msm_rpmrs_level *levels, int size)
{
	msm_rpmrs_levels = kzalloc(sizeof(struct msm_rpmrs_level) * size,
			GFP_KERNEL);
	if (!msm_rpmrs_levels)
		return -ENOMEM;
	msm_rpmrs_level_count = size;
	memcpy(msm_rpmrs_levels, levels, size * sizeof(struct msm_rpmrs_level));

	return 0;
}

static int __init msm_rpmrs_init(void)
{
	struct msm_rpm_iv_pair req;
	int rc;

	BUG_ON(!msm_rpmrs_levels);

	if (cpu_is_msm8x60()) {
		req.id = MSM_RPMRS_ID_APPS_L2_CACHE_CTL;
		req.value = 1;

		rc = msm_rpm_set(MSM_RPM_CTX_SET_0, &req, 1);
		if (rc) {
			pr_err("%s: failed to request L2 cache: %d\n",
				__func__, rc);
			goto init_exit;
		}

		req.id = MSM_RPMRS_ID_APPS_L2_CACHE_CTL;
		req.value = 0;

		rc = msm_rpmrs_set(MSM_RPM_CTX_SET_SLEEP, &req, 1);
		if (rc) {
			pr_err("%s: failed to initialize L2 cache for sleep: "
				"%d\n", __func__, rc);
			goto init_exit;
		}
	}

	/* Enable RPM SWFI on Apps initialization */
	req.id = MSM_RPMRS_ID_RPM_CTL;
	req.value = 0;

	rc = msm_rpmrs_set(MSM_RPM_CTX_SET_0, &req, 1);
	if (rc) {
		pr_err("%s: failed to initialize RPM halt: "
		       "%d\n", __func__, rc);
		goto init_exit;
	}

	rc = msm_rpmrs_resource_sysfs_add();

init_exit:
	return rc;
}
device_initcall(msm_rpmrs_init);

static int __init msm_rpmrs_early_init(void)
{
	int i, k;

	/* Initialize listed bitmap for valid resource IDs */
	for (i = 0; i < ARRAY_SIZE(msm_rpmrs_resources); i++) {
		for (k = 0; k < msm_rpmrs_resources[i]->size; k++)
			set_bit(msm_rpmrs_resources[i]->rs[k].id,
				msm_rpmrs_listed);
	}

	return 0;
}
early_initcall(msm_rpmrs_early_init);

#ifdef CONFIG_MSM_L2_SPM
static int __init msm_rpmrs_l2_counter_init(void)
{
	msm_rpmrs_l2_counter_addr = MSM_IMEM_BASE + L2_PC_COUNTER_ADDR;
	writel_relaxed(msm_rpmrs_l2_reset_count, msm_rpmrs_l2_counter_addr);
	mb();

	msm_rpmrs_l2_cache.beyond_limits = msm_spm_l2_cache_beyond_limits;
	msm_rpmrs_l2_cache.aggregate = NULL;
	msm_rpmrs_l2_cache.restore = NULL;

	register_hotcpu_notifier(&rpmrs_cpu_notifier);

	return 0;
}
early_initcall(msm_rpmrs_l2_counter_init);
#endif