// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Western Digital Corporation

#include <linux/err.h>
#include <linux/string.h>

#include "ufs-sysfs.h"

static const char *ufschd_uic_link_state_to_string(
			enum uic_link_state state)
{
	switch (state) {
	case UIC_LINK_OFF_STATE:	return "OFF";
	case UIC_LINK_ACTIVE_STATE:	return "ACTIVE";
	case UIC_LINK_HIBERN8_STATE:	return "HIBERN8";
	default:			return "UNKNOWN";
	}
}

static const char *ufschd_ufs_dev_pwr_mode_to_string(
			enum ufs_dev_pwr_mode state)
{
	switch (state) {
	case UFS_ACTIVE_PWR_MODE:	return "ACTIVE";
	case UFS_SLEEP_PWR_MODE:	return "SLEEP";
	case UFS_POWERDOWN_PWR_MODE:	return "POWERDOWN";
	default:			return "UNKNOWN";
	}
}

static inline ssize_t ufs_sysfs_pm_lvl_store(struct device *dev,
					     struct device_attribute *attr,
					     const char *buf, size_t count,
					     bool rpm)
{
	struct ufs_hba *hba = dev_get_drvdata(dev);
	unsigned long flags, value;

	if (kstrtoul(buf, 0, &value))
		return -EINVAL;

	if (value >= UFS_PM_LVL_MAX)
		return -EINVAL;

	spin_lock_irqsave(hba->host->host_lock, flags);
	if (rpm)
		hba->rpm_lvl = value;
	else
		hba->spm_lvl = value;
	spin_unlock_irqrestore(hba->host->host_lock, flags);
	return count;
}

static ssize_t rpm_lvl_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct ufs_hba *hba = dev_get_drvdata(dev);
	int curr_len;
	u8 lvl;

	curr_len = snprintf(buf, PAGE_SIZE,
			    "\nCurrent Runtime PM level [%d] => dev_state [%s] link_state [%s]\n",
			    hba->rpm_lvl,
			    ufschd_ufs_dev_pwr_mode_to_string(
				ufs_pm_lvl_states[hba->rpm_lvl].dev_state),
			    ufschd_uic_link_state_to_string(
				ufs_pm_lvl_states[hba->rpm_lvl].link_state));

	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
			     "\nAll available Runtime PM levels info:\n");
	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
				     "\tRuntime PM level [%d] => dev_state [%s] link_state [%s]\n",
				    lvl,
				    ufschd_ufs_dev_pwr_mode_to_string(
					ufs_pm_lvl_states[lvl].dev_state),
				    ufschd_uic_link_state_to_string(
					ufs_pm_lvl_states[lvl].link_state));

	return curr_len;
}

static ssize_t rpm_lvl_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return ufs_sysfs_pm_lvl_store(dev, attr, buf, count, true);
}

static ssize_t spm_lvl_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct ufs_hba *hba = dev_get_drvdata(dev);
	int curr_len;
	u8 lvl;

	curr_len = snprintf(buf, PAGE_SIZE,
			    "\nCurrent System PM level [%d] => dev_state [%s] link_state [%s]\n",
			    hba->spm_lvl,
			    ufschd_ufs_dev_pwr_mode_to_string(
				ufs_pm_lvl_states[hba->spm_lvl].dev_state),
			    ufschd_uic_link_state_to_string(
				ufs_pm_lvl_states[hba->spm_lvl].link_state));

	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
			     "\nAll available System PM levels info:\n");
	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
				     "\tSystem PM level [%d] => dev_state [%s] link_state [%s]\n",
				    lvl,
				    ufschd_ufs_dev_pwr_mode_to_string(
					ufs_pm_lvl_states[lvl].dev_state),
				    ufschd_uic_link_state_to_string(
					ufs_pm_lvl_states[lvl].link_state));

	return curr_len;
}

static ssize_t spm_lvl_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return ufs_sysfs_pm_lvl_store(dev, attr, buf, count, false);
}

static DEVICE_ATTR_RW(rpm_lvl);
static DEVICE_ATTR_RW(spm_lvl);

static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
	&dev_attr_rpm_lvl.attr,
	&dev_attr_spm_lvl.attr,
	NULL
};

static const struct attribute_group ufs_sysfs_default_group = {
	.attrs = ufs_sysfs_ufshcd_attrs,
};

static const struct attribute_group *ufs_sysfs_groups[] = {
	&ufs_sysfs_default_group,
	NULL,
};

void ufs_sysfs_add_nodes(struct device *dev)
{
	int ret;

	ret = sysfs_create_groups(&dev->kobj, ufs_sysfs_groups);
	if (ret)
		dev_err(dev,
			"%s: sysfs groups creation failed (err = %d)\n",
			__func__, ret);
}

void ufs_sysfs_remove_nodes(struct device *dev)
{
	sysfs_remove_groups(&dev->kobj, ufs_sysfs_groups);
}