/* * ./kernel_modules/pse/pse-sysfs.c
 *
 * This file defines the sysfs interface for the PSE class
 *
 * Author: Cradlepoint Technology, Inc.  <source@cradlepoint.com>
 *		Kyle Swenson <kswenson@cradlepoint.com>
 *
 * Copyright 2017 Cradlepoint Technology, Inc.
 *
 * 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.
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/idr.h>
#include <linux/spinlock.h>
#include <linux/list_sort.h>
#include <linux/sort.h>

#include "pse-port.h"
#include "pse-class.h"
#include "pse-sysfs.h"

char *pse_detect_strings[] = {
	"0:DETECT_NO_DEVICE",
	"1:DETECT_NORMAL_DEVICE", /* Short */
	"2:DETECT_LEGACY_DEVICE", /* High cap devices */
	"3:DETECT_POWERED_DEVICE",/* Signature resistance good */ /* Maybe we want to even break this down into detect Type of device iff that's a detect-time thing */
	"4:DETECT_ERROR",
	NULL
};
EXPORT_SYMBOL(pse_detect_strings);
char *pse_class_strings[] = {
	"0:PD_CLASS_UNKNOWN",
	"1:PD_CLASS_1",
	"2:PD_CLASS_2",
	"3:PD_CLASS_3",
	"4:PD_CLASS_4",
	"5:PD_CLASS_5",
	"6:PD_CLASS_6",
	"7:PD_CLASS_7",
	"8:PD_CLASS_8",
	"1D:PD_CLASS_1D",
	"2D:PD_CLASS_2D",
	"3D:PD_CLASS_3D",
	"4D:PD_CLASS_4D",
	"5D:PD_CLASS_5D",
	"9:PD_CLASS_INVALID",
	NULL
};
EXPORT_SYMBOL(pse_class_strings);

uint16_t pse_port_current_table[] = {
			375, /* Class 0 (unknown) */
			112, /* Class 1 */
			206, /* Class 2 */
			375, /* Class 3 */
			638, /* Class 4 (Type 2) */
			938, /* Class 5 */
			1250, /* Class 6 */
			1563, /* Class 7 */
			1875, /* Class 8 */
			2*112, /* Class 1D */
			2*206, /* Class 2D */
			2*375, /* Class 3D */
			2*638, /* Class 4D  */
			2*938 /* Class 5D */
};

uint32_t pse_port_power_table[] = {
			15400, /* Class 0 (unknown) */
			4000, /* Class 1  */
			7000, /* Class 2 */
			15400, /* Class 3  */
			30000, /* Class 4  */
			45000, /* Class 5 */
			60000, /* Class 6 */
			75000, /* Class 7 */
			90000, /* Class 8 */
			2*4000, /* Class 1D  */
			2*7000, /* Class 2D */
			2*15400, /* Class 3D  */
			2*30000, /* Class 4D  */
			2*45000, /* Class 5D */
};
EXPORT_SYMBOL(pse_port_power_table);
/* ============ PSE CLASS ATTRIBUTES =================
* PSE Class level attributes; these appear under /sys/class/pse/
*/
static ssize_t
pse_version_show(struct class *class, struct class_attribute *attr, char *buf)
{
	return sprintf(buf, "%s\n", PSE_VERSION_STR);
}

static struct class_attribute pse_version = __ATTR_RO(pse_version);


/* -1 for false
 * 0 for no idea
 * +1 for true
 */
static int is_trueish(const char *buf, size_t len)
{
	if (len == 0)
		return 0;

	switch (buf[0]) {
	case '1':
		/* ASCII char 0x31 => '1' means true*/
	case 'y':
	case 'Y':
		/* [yY].*  */
	case 't':
	case 'T':
		/* [tT].*  */
	case 'e':
	case 'E':
		/* [eE] for enable */
		return 1;
	case '0':
		/* ASCII char 0x30 => '0' means false */
	case 'n':
	case 'N':
		/* [nN].* for No  */
	case 'F':
	case 'f':
		/* [fF].* for false */
	case 'd':
	case 'D':
		/* [dD] for disable*/
		return -1;
	case 'o':
	case 'O':
		/* Could be On, or Off need to look more */
		break;
	default:
		/* Bail if we don't recognize the first char */
		return 0;
	}
	/*If we're here we know the first char is [oO] */
	/* But if we've only got one char in the buffer, we can't determine so bail*/
	if (len == 1)
		return 0;

	/* Here, we know len > 1, so at least two  */
	switch (buf[1]) {
	case 'n':
	case 'N':
		/* for [oO][nN].* */
		return 1;
	case 'f':
	case 'F':
		/* for [oO][fF].* */
		return -1;
	default:
		return 0;
	}
	return 0;
}

static ssize_t
port_priority_show(struct class *class, struct class_attribute *attr, char *buf)
{
	struct class_dev_iter iter;
	struct device *dev;
	int bput = 0;

	class_dev_iter_init(&iter, class, NULL, NULL);
	dev = class_dev_iter_next(&iter);
	while (dev) {
		bput += snprintf((char *)(buf+bput), 32,  "port%d -> priority %d\n", to_pse_port_device(dev)->id, to_pse_port_device(dev)->priority);
		dev = class_dev_iter_next(&iter);
	}
	class_dev_iter_exit(&iter);
	return bput;
}

/* We are implying port and specifying priority:
 * |Port 0 relative priority 2
 * | |Port 1 is priority 3
 * | | |Port 2 has priority 1
 * | | | |Port 3 is priority 0 (highest)
 * 2 3 1 0
 *
*/
static ssize_t
port_priority_store(struct class *class, struct class_attribute *attr, const char *buff, size_t count)
{
	struct device *dev;
	struct class_dev_iter iter;
	char *substr;
	char *lbuffs;

	int vi = 0;
	size_t bget = 0;
	uint8_t port_priority = 0;
	struct pse_data *pse_data = get_pse_data(class);
	struct pse_port_device *port;
	char *local_buff = kcalloc(count, sizeof(char), GFP_KERNEL);

	lbuffs = memcpy((char *) local_buff, (const char *) buff, count);

	mutex_lock(&pse_data->pse_lock);
	while (bget < count && vi < PSE_MAX_PORTS) {
		substr = strsep(&lbuffs, " ");
		if (substr == NULL) {
			break;
		}
		printk(KERN_INFO "Looking at substr = %s\n", substr);
		if (kstrtou8(substr, 0, &port_priority) == 0) {
			pse_data->port_priorities[vi++] = port_priority;
			bget += strlen(substr);
		} else {
			printk(KERN_WARNING "Unable to parse the number out of %s\n", substr);
		}
	}
	class_dev_iter_init(&iter, class, NULL, NULL);
	dev = class_dev_iter_next(&iter);
	while (dev) {
		port = to_pse_port_device(dev);
		port->priority = pse_data->port_priorities[port->id];
		dev_dbg(dev, "Storing port_priority %hhu to port%u", port->priority,  port->id);
		dev = class_dev_iter_next(&iter);
	}
	class_dev_iter_exit(&iter);
	relink_priority_list(class); /* Rebuild the dubly linked list */
	redistribute_power(class); /* Force every port off & on again, to get them to repower in correct, priority order */
	mutex_unlock(&pse_data->pse_lock);

	kfree(local_buff);
	return count;
}
static struct class_attribute port_priority = __ATTR_RW(port_priority);

static ssize_t
power_budget_show(struct class *class, struct class_attribute *attr, char *buf)
{
	struct pse_data *pse_data = get_pse_data(class);

	return sprintf(buf, "%d", pse_data->power_budget);
}
static ssize_t
power_budget_store(struct class *class, struct class_attribute *attr, const char *buff, size_t count)
{
	int new;
	int res;
	struct pse_data *pse_data = get_pse_data(class);

	res = kstrtoint(buff, 0, &new);
	if (res != 0)
		return res;
	mutex_lock(&pse_data->pse_lock);
	pse_data->power_budget = new;
	redistribute_power(&pse_data->cls);
	mutex_unlock(&pse_data->pse_lock);
	return count;
}
static struct class_attribute power_budget = __ATTR_RW(power_budget);

static ssize_t
enable_show(struct class *class, struct class_attribute *attr, char *buf)
{
	struct pse_data *pse_data = get_pse_data(class);

	return sprintf(buf, pse_data->enabled ? "True" : "False");
}

static ssize_t
enable_store(struct class *class, struct class_attribute *attr, const char *buf, size_t count)
{

	struct pse_data *pse_data = get_pse_data(class);
	int t = is_trueish(buf, count);

	if (t == 0)
		return -EINVAL;

	mutex_lock(&pse_data->pse_lock);
	if (t > 0)
		pse_data->enabled = 1;
	else
		pse_data->enabled = 0;

	redistribute_power(class);
	mutex_unlock(&pse_data->pse_lock);
	return count;
}
static struct class_attribute enable = __ATTR_RW(enable);

static ssize_t
power_used_show(struct class *class, struct class_attribute *attr, char *buf)
{
	struct pse_data *pse_data = get_pse_data(class);

	return sprintf(buf, "%d", pse_data->power_used);
}
static struct class_attribute power_used = __ATTR_RO(power_used);

int pse_class_sysfs_init(struct class *class)
{
	int err;

	err = class_create_file(class, &pse_version);
	if (err) {
		pr_err("couldn't register pse class version file\n");
		return err;
	}
	err = class_create_file(class, &port_priority);
	if (err) {
		pr_err("couldn't register pse class port priority file\n");
		return err;
	}
	err = class_create_file(class, &power_budget);
	if (err) {
		pr_err("couldn't register pse class port priority file\n");
		return err;
	}
	err = class_create_file(class, &enable);
	if (err) {
		pr_err("couldn't register pse class enable file\n");
		return err;
	}
	err = class_create_file(class, &power_used);
	if (err) {
		pr_err("couldn't register pse class enable file\n");
		return err;
	}
	return 0;
}
void pse_class_sysfs_close(struct class *class)
{
	class_remove_file(class, &pse_version);
	class_remove_file(class, &port_priority);
	class_remove_file(class, &power_budget);
	class_remove_file(class, &enable);
	class_remove_file(class, &power_used);
}


/* ============= PSE PORT DEVICE ATTRIBUTES ==================
 * These are attributes that appear at /sys/class/pse/portX/<attribute>
 * These Attributes DO NOT EXIST until a device driver has registered a port device with the pse class!
 */

/* current_show : Display the current in mA being sourced by the port
*/
static ssize_t
pd_current_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	int pd_current = 0;
	struct pse_port_device *port = to_pse_port_device(dev);

	dev_dbg(dev, "%s:%d\n", __func__, __LINE__);
	if (!port || !port->ops->pd_current || !port->ops->pd_powered)
		return -EINVAL;

	if (port->enabled && port->ops->pd_powered(dev))
		pd_current = to_pse_port_device(dev)->ops->pd_current(dev);

	return sprintf(buf, "%d\n", pd_current);
}

static struct device_attribute port_current = __ATTR_RO(pd_current);

/* voltage_show: Show the port's voltage
 */
static ssize_t
port_enable_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	return sprintf(buf,
		to_pse_port_device(dev)->enabled ? "True" : "False");
}

static ssize_t
port_enable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	int t = is_trueish(buf, count);
	struct pse_port_device *port = to_pse_port_device(dev);

	if (t == 0)
		return -EINVAL;

	mutex_lock(&port->lock);

	if (t < 0) {
		port->enabled = 0;
		queue_work(port->wq, &port->disconnect);
	} else {
		port->enabled = 1;
	}
	mutex_unlock(&port->lock);

	return count;
}
static struct device_attribute port_enable = __ATTR_RW(port_enable);
/* voltage_show: Show the port's voltage
 */
static ssize_t
pd_voltage_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	int pd_voltage = 0;
	struct pse_port_device *port = to_pse_port_device(dev);

	if (!port || !port->ops->pd_voltage || !port->ops->pd_powered)
		return -EINVAL;

	if (port->enabled && port->ops->pd_powered(dev)) {
		pd_voltage = port->ops->pd_voltage(dev);
	}
	return sprintf(buf, "%d\n", pd_voltage);
}

static struct device_attribute port_voltage = __ATTR_RO(pd_voltage);

/* class_show : Show the port's last classification result
*/
static ssize_t
class_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	uint8_t lc;
	struct pse_port_device *p = to_pse_port_device(dev);

	if (!p->enabled) {
		return sprintf(buf, "%s", pse_class_strings[CLASS_INVALID]);
	}
	if (p->ops->update_classification) {
		p->ops->update_classification(dev);
	} else {
		mutex_lock(&p->lock);
		p->last_class_result = p->ops->last_classification(dev);
		mutex_unlock(&p->lock);
	}

	mutex_lock(&p->lock);
	lc = p->last_class_result;
	mutex_unlock(&p->lock);

	if (lc > CLASS_INVALID) {
		dev_warn(dev, "PSE Class saw invalid class code 0x%02X\n", lc);
		lc = CLASS_INVALID;
	}
	return sprintf(buf, "%s", pse_class_strings[lc]);
}

static ssize_t
class_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	int t;
	struct pse_port_device *port = to_pse_port_device(dev);

	if (!port || !port->ops->enable_classify)
		return -EINVAL;

	t = is_trueish(buf, count);
	if (t == 0)
		return -EINVAL;

	if (t < 0) {
		dev_dbg(dev, "disabling classification for port %d\n", to_pse_port_device(dev)->port_id);
		port->ops->enable_classify(dev, 0);
	} else {
		dev_dbg(dev, "enabling classification for port %d\n", to_pse_port_device(dev)->port_id);
		port->ops->enable_classify(dev, 1);
	}
	return count;
}
static struct device_attribute port_class = __ATTR_RW(class);

/* detect_show : show the ports' last detection_result
*/
static ssize_t
detect_show(struct device *dev, struct device_attribute *attr, char *buf)
{

	uint8_t detval;
	struct pse_port_device *p = to_pse_port_device(dev);

	if (!p->enabled) {
		return sprintf(buf, "%s", pse_detect_strings[DETECT_NO_DEVICE]);
	}
	if (p->ops->update_detection) {
		p->ops->update_detection(dev);
	} else {
		mutex_lock(&p->lock);
		p->last_detect_result = p->ops->last_detection(dev);
		mutex_unlock(&p->lock);
	}
	mutex_lock(&p->lock);
	detval = p->last_detect_result;
	mutex_unlock(&p->lock);

	if (detval >=  PSE_NUM_DETECT_EVENTS) {
		dev_warn(dev, "PSE class saw an invalid detection code 0x%02x\n", detval);
		detval = DETECT_ERROR;
	}
	return sprintf(buf,  "%s", pse_detect_strings[detval]);
}
static ssize_t
detect_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	int enable;
	struct pse_port_device *port = to_pse_port_device(dev);

	if (!port || !port->ops->enable_detect)
		return -EINVAL;

	enable = is_trueish(buf, count);
	if (enable == 0)
		return -EINVAL;

	if (enable < 0) {
		port->ops->enable_detect(dev, 0);
		dev_dbg(dev, "disabling detection for port %d\n", to_pse_port_device(dev)->port_id);
	} else {
		port->ops->enable_detect(dev, 1);
		dev_dbg(dev, "enabling detection for port %d\n", to_pse_port_device(dev)->port_id);
	}
	return count;
}
static struct device_attribute port_detect = __ATTR_RW(detect);

/*port_power_allocation_show: Show the allocation for this port
*/
static ssize_t
port_power_allocation_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pse_port_device *port = to_pse_port_device(dev);

	if (!port)
		return -EINVAL;

	return sprintf(buf, "%d", port->power_allocation);
}

/*port_power_allocation_store: Request a power allocation change for this port
*/
static ssize_t
port_power_allocation_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	uint32_t power_request;
	struct pse_port_device *port = to_pse_port_device(dev);
	if (!port)
		return -EINVAL;

	if (kstrtou32(buf, 0, &power_request) != 0)
		return -EINVAL;

	dev_info(dev, "Got %u mW for power request\n", power_request);
	mutex_lock(&port->lock);
	port->power_request = power_request;
	queue_work(port->wq, &port->request_power);
	mutex_unlock(&port->lock);

	return count;
}
static struct device_attribute port_power_allocation = __ATTR_RW(port_power_allocation);


/* port_power_store : power "on/off" a port */
static ssize_t
port_power_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	int t;

	dev_dbg(dev, "%s:%d\n", __func__, __LINE__);
	if (!to_pse_port_device(dev)->ops->apply_power)
		return -EINVAL;

	t = is_trueish(buf, count);
	if (t == 0)
		return -EINVAL;

	if (t > 0)
		to_pse_port_device(dev)->ops->apply_power(dev, 1);
	else
		to_pse_port_device(dev)->ops->apply_power(dev, 0);

	return count;

}
static ssize_t
port_power_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	if (!to_pse_port_device(dev)->ops->pd_powered)
		return -EINVAL;

	return sprintf(buf, to_pse_port_device(dev)->ops->pd_powered(dev) ? "True" : "False");
}
static struct device_attribute port_power = __ATTR_RW(port_power);


static ssize_t
config_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pse_port_config config;

	if (!to_pse_port_device(dev)->ops->get_config)
		return -EINVAL;

	to_pse_port_device(dev)->ops->get_config(dev, &config);

	return sprintf(buf, "enabled:%s\nmanaged:%s\ntype:%d\n"
						"disconnect_detection:%s\npd_detection_enabled:%s\n"
						"pd_classification_enabled:%s\n"
						"legacy_device_enable:%s\ncurrent_limit:%d\n",
						(config.enabled ? "True" : "False"),
						(config.managed ? "True" : "False"),
						(config.port_type+1),
						(config.disconnect_event ? "True" : "False"),
						(config.detect_enable ? "True" : "False"),
						(config.classify_enable ? "True" : "False"),
						(config.legacy_enable ? "True" : "False"),
						config.current_limit);

}
static struct device_attribute port_config = __ATTR_RO(config);

static ssize_t
reset_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	if (!to_pse_port_device(dev)->ops->reset)
		return -EINVAL;

	to_pse_port_device(dev)->ops->reset(dev);
	return count;
}
static struct device_attribute port_reset = __ATTR_WO(reset);

struct attribute *dev_attrs[] = {
	&port_current.attr,
	&port_voltage.attr,
	&port_class.attr,
	&port_detect.attr,
	&port_power.attr,
	&port_power_allocation.attr,
	&port_enable.attr,
	&port_config.attr,
	&port_reset.attr,
	NULL,
};

struct attribute_group dev_attr_group = {
	.attrs = dev_attrs,

};

const struct attribute_group *pse_port_dev_attr_groups[] = {
	&dev_attr_group,
	NULL,
};