/* Copyright (c) 2012-2015, The Linux Foundation. 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/slab.h>
#include <soc/qcom/pm.h>

#define GET_CPU_OF_ATTR(attr) \
	(container_of(attr, struct msm_pm_kobj_attribute, ka)->cpu)

struct msm_pm_platform_data {
	u8 idle_supported;   /* Allow device to enter mode during idle */
	u8 suspend_supported; /* Allow device to enter mode during suspend */
	u8 suspend_enabled;  /* enabled for suspend */
	u8 idle_enabled;     /* enabled for idle low power */
	u32 latency;         /* interrupt latency in microseconds when entering
				and exiting the low power mode */
	u32 residency;       /* time threshold in microseconds beyond which
				staying in the low power mode saves power */
};

static struct msm_pm_platform_data msm_pm_sleep_modes[] = {
	[MSM_PM_MODE(0, MSM_PM_SLEEP_MODE_POWER_COLLAPSE_SUSPEND)] = {
		.idle_supported = 0,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 1,
	},

	[MSM_PM_MODE(0, MSM_PM_SLEEP_MODE_POWER_COLLAPSE)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(0, MSM_PM_SLEEP_MODE_POWER_COLLAPSE_STANDALONE)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(0, MSM_PM_SLEEP_MODE_RETENTION)] = {
		.idle_supported = 1,
		.suspend_supported = 0,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(0, MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 1,
		.suspend_enabled = 1,
	},

	[MSM_PM_MODE(1, MSM_PM_SLEEP_MODE_POWER_COLLAPSE)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 1,
	},

	[MSM_PM_MODE(1, MSM_PM_SLEEP_MODE_POWER_COLLAPSE_SUSPEND)] = {
		.idle_supported = 0,
		.suspend_supported = 0,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(1, MSM_PM_SLEEP_MODE_POWER_COLLAPSE_STANDALONE)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(1, MSM_PM_SLEEP_MODE_RETENTION)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(1, MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT)] = {
		.idle_supported = 1,
		.suspend_supported = 0,
		.idle_enabled = 1,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(2, MSM_PM_SLEEP_MODE_POWER_COLLAPSE_SUSPEND)] = {
		.idle_supported = 0,
		.suspend_supported = 0,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(2, MSM_PM_SLEEP_MODE_POWER_COLLAPSE)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 1,
	},

	[MSM_PM_MODE(2, MSM_PM_SLEEP_MODE_POWER_COLLAPSE_STANDALONE)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(2, MSM_PM_SLEEP_MODE_RETENTION)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(2, MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT)] = {
		.idle_supported = 1,
		.suspend_supported = 0,
		.idle_enabled = 1,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(3, MSM_PM_SLEEP_MODE_POWER_COLLAPSE_SUSPEND)] = {
		.idle_supported = 0,
		.suspend_supported = 0,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(3, MSM_PM_SLEEP_MODE_POWER_COLLAPSE)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 1,
	},

	[MSM_PM_MODE(3, MSM_PM_SLEEP_MODE_POWER_COLLAPSE_STANDALONE)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(3, MSM_PM_SLEEP_MODE_RETENTION)] = {
		.idle_supported = 1,
		.suspend_supported = 1,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(3, MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT)] = {
		.idle_supported = 1,
		.suspend_supported = 0,
		.idle_enabled = 1,
		.suspend_enabled = 0,
	},

	[MSM_PM_MODE(3, MSM_PM_SLEEP_MODE_NR)] = {
		.idle_supported = 0,
		.suspend_supported = 0,
		.idle_enabled = 0,
		.suspend_enabled = 0,
	},
};

enum {
	MSM_PM_MODE_ATTR_SUSPEND,
	MSM_PM_MODE_ATTR_IDLE,
	MSM_PM_MODE_ATTR_NR,
};

static char *msm_pm_mode_attr_labels[MSM_PM_MODE_ATTR_NR] = {
	[MSM_PM_MODE_ATTR_SUSPEND] = "suspend_enabled",
	[MSM_PM_MODE_ATTR_IDLE] = "idle_enabled",
};

struct msm_pm_kobj_attribute {
	unsigned int cpu;
	struct kobj_attribute ka;
};

struct msm_pm_sysfs_sleep_mode {
	struct kobject *kobj;
	struct attribute_group attr_group;
	struct attribute *attrs[MSM_PM_MODE_ATTR_NR + 1];
	struct msm_pm_kobj_attribute kas[MSM_PM_MODE_ATTR_NR];
};

static char *msm_pm_sleep_mode_labels[MSM_PM_SLEEP_MODE_NR] = {
	[MSM_PM_SLEEP_MODE_POWER_COLLAPSE] = "power_collapse",
	[MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT] = "wfi",
	[MSM_PM_SLEEP_MODE_RETENTION] = "retention",
	[MSM_PM_SLEEP_MODE_POWER_COLLAPSE_STANDALONE] =
		"standalone_power_collapse",
	[MSM_PM_SLEEP_MODE_FASTPC] =
		"fpc",
};

/*
 * Write out the attribute.
 */
static ssize_t msm_pm_mode_attr_show(
	struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
	int ret = -EINVAL;
	int i;

	for (i = 0; i < MSM_PM_SLEEP_MODE_NR; i++) {
		struct kernel_param kp;
		unsigned int cpu;
		struct msm_pm_platform_data *mode;

		if (msm_pm_sleep_mode_labels[i] == NULL)
			continue;

		if (strcmp(kobj->name, msm_pm_sleep_mode_labels[i]))
			continue;

		cpu = GET_CPU_OF_ATTR(attr);
		mode = &msm_pm_sleep_modes[MSM_PM_MODE(cpu, i)];

		if (!strcmp(attr->attr.name,
			msm_pm_mode_attr_labels[MSM_PM_MODE_ATTR_SUSPEND])) {
			u32 arg = mode->suspend_enabled;
			kp.arg = &arg;
			ret = param_get_int(buf, &kp);
		} else if (!strcmp(attr->attr.name,
			msm_pm_mode_attr_labels[MSM_PM_MODE_ATTR_IDLE])) {
			u32 arg = mode->idle_enabled;
			kp.arg = &arg;
			ret = param_get_int(buf, &kp);
		}

		break;
	}

	if (ret > 0) {
		strlcat(buf, "\n", PAGE_SIZE);
		ret++;
	}

	return ret;
}

static ssize_t msm_pm_mode_attr_store(struct kobject *kobj,
	struct kobj_attribute *attr, const char *buf, size_t count)
{
	int ret = -EINVAL;
	int i;

	for (i = 0; i < MSM_PM_SLEEP_MODE_NR; i++) {
		struct kernel_param kp;
		unsigned int cpu;
		struct msm_pm_platform_data *mode;

		if (msm_pm_sleep_mode_labels[i] == NULL)
			continue;

		if (strcmp(kobj->name, msm_pm_sleep_mode_labels[i]))
			continue;

		cpu = GET_CPU_OF_ATTR(attr);
		mode = &msm_pm_sleep_modes[MSM_PM_MODE(cpu, i)];

		if (!strcmp(attr->attr.name,
			msm_pm_mode_attr_labels[MSM_PM_MODE_ATTR_SUSPEND])) {
			kp.arg = &mode->suspend_enabled;
			ret = param_set_byte(buf, &kp);
		} else if (!strcmp(attr->attr.name,
			msm_pm_mode_attr_labels[MSM_PM_MODE_ATTR_IDLE])) {
			kp.arg = &mode->idle_enabled;
			ret = param_set_byte(buf, &kp);
		}

		break;
	}

	return ret ? ret : count;
}

static int msm_pm_mode_sysfs_add_cpu(
	unsigned int cpu, struct kobject *modes_kobj)
{
	char cpu_name[8];
	struct kobject *cpu_kobj;
	struct msm_pm_sysfs_sleep_mode *mode = NULL;
	int i, j, k;
	int ret;

	snprintf(cpu_name, sizeof(cpu_name), "cpu%u", cpu);
	cpu_kobj = kobject_create_and_add(cpu_name, modes_kobj);
	if (!cpu_kobj) {
		pr_err("%s: cannot create %s kobject\n", __func__, cpu_name);
		ret = -ENOMEM;
		goto mode_sysfs_add_cpu_exit;
	}

	for (i = 0; i < MSM_PM_SLEEP_MODE_NR; i++) {
		int idx = MSM_PM_MODE(cpu, i);

		if ((!msm_pm_sleep_modes[idx].suspend_supported)
			&& (!msm_pm_sleep_modes[idx].idle_supported))
			continue;

		if (!msm_pm_sleep_mode_labels[i] ||
				!msm_pm_sleep_mode_labels[i][0])
			continue;

		mode = kzalloc(sizeof(*mode), GFP_KERNEL);
		if (!mode) {
			pr_err("%s: cannot allocate memory for attributes\n",
				__func__);
			ret = -ENOMEM;
			goto mode_sysfs_add_cpu_exit;
		}

		mode->kobj = kobject_create_and_add(
				msm_pm_sleep_mode_labels[i], cpu_kobj);
		if (!mode->kobj) {
			pr_err("%s: cannot create kobject\n", __func__);
			ret = -ENOMEM;
			goto mode_sysfs_add_cpu_exit;
		}

		for (k = 0, j = 0; k < MSM_PM_MODE_ATTR_NR; k++) {
			if ((k == MSM_PM_MODE_ATTR_IDLE) &&
				!msm_pm_sleep_modes[idx].idle_supported)
				continue;
			if ((k == MSM_PM_MODE_ATTR_SUSPEND) &&
			     !msm_pm_sleep_modes[idx].suspend_supported)
				continue;
			sysfs_attr_init(&mode->kas[j].ka.attr);
			mode->kas[j].cpu = cpu;
			mode->kas[j].ka.attr.mode = 0644;
			mode->kas[j].ka.show = msm_pm_mode_attr_show;
			mode->kas[j].ka.store = msm_pm_mode_attr_store;
			mode->kas[j].ka.attr.name = msm_pm_mode_attr_labels[k];
			mode->attrs[j] = &mode->kas[j].ka.attr;
			j++;
		}
		mode->attrs[j] = NULL;

		mode->attr_group.attrs = mode->attrs;
		ret = sysfs_create_group(mode->kobj, &mode->attr_group);
		if (ret) {
			pr_err("%s: cannot create kobject attribute group\n",
				__func__);
			goto mode_sysfs_add_cpu_exit;
		}
	}

	ret = 0;

mode_sysfs_add_cpu_exit:
	if (ret) {
		if (mode && mode->kobj)
			kobject_del(mode->kobj);
		kfree(mode);
	}

	return ret;
}

int msm_pm_mode_sysfs_add(const char *pm_modname)
{
	struct kobject *module_kobj;
	struct kobject *modes_kobj;
	unsigned int cpu;
	int ret;

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

	modes_kobj = kobject_create_and_add("modes", module_kobj);
	if (!modes_kobj) {
		pr_err("%s: cannot create modes kobject\n", __func__);
		ret = -ENOMEM;
		goto mode_sysfs_add_exit;
	}

	for_each_possible_cpu(cpu) {
		ret = msm_pm_mode_sysfs_add_cpu(cpu, modes_kobj);
		if (ret)
			goto mode_sysfs_add_exit;
	}

	ret = 0;

mode_sysfs_add_exit:
	return ret;
}

int msm_pm_sleep_mode_supported(unsigned int cpu,
		unsigned int mode, bool idle)
{
	int idx = MSM_PM_MODE(cpu, mode);
	if (idle)
		return msm_pm_sleep_modes[idx].idle_supported;
	else
		return msm_pm_sleep_modes[idx].suspend_supported;
}
EXPORT_SYMBOL(msm_pm_sleep_mode_supported);

int msm_pm_sleep_mode_allow(unsigned int cpu,
		unsigned int mode, bool idle)
{
	int idx = MSM_PM_MODE(cpu, mode);

	if ((mode == MSM_PM_SLEEP_MODE_RETENTION)
			&&  !msm_pm_retention_enabled())
		return false;

	if (idle)
		return msm_pm_sleep_modes[idx].idle_enabled &&
			msm_pm_sleep_modes[idx].idle_supported;
	else
		return msm_pm_sleep_modes[idx].suspend_enabled &&
			msm_pm_sleep_modes[idx].suspend_supported;
}
EXPORT_SYMBOL(msm_pm_sleep_mode_allow);