/*
 * tps23880-ops.c
 *
 * TPS23880 PSE port implementation
 *
 * 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/mutex.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/device.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include "../pse-port.h"
#include "tps23880.h"
#include "tps23880-regdefs.h"


static int tps23880_voltage(struct device *dev);
static int tps23880_current(struct device *dev);
static int tps23880_update_detection(struct device *dev);
static int tps23880_apply_power(struct device *dev, unsigned enabled);
static int tps23880_pd_powered(struct device *dev);
static int tps23880_configure_port(struct device *dev, struct pse_port_config *config);
static int tps23880_get_config(struct device *dev, struct pse_port_config *config);
static int tps23880_port_reset(struct device *dev);
static int tps23880_port_set_power_limit(struct device *dev, int current_limit);
static int tps23880_port_get_power_limit(struct device *dev);
static int tps23880_port_enable_classify(struct device *dev, int enable);
static int tps23880_port_enable_detect(struct device *dev, int enable);

/* Caller will lock */
struct pse_port_ops tps23880_port_ops = {
	.pd_voltage = tps23880_voltage,
	.pd_current = tps23880_current,
	.last_classification = NULL,
	.last_detection = NULL,
	.update_detection = tps23880_update_detection,
	.update_classification = tps23880_update_detection,
	.apply_power = tps23880_apply_power,
	.pd_powered = tps23880_pd_powered,
	.configure = tps23880_configure_port,
	.status = NULL,
	.get_config = tps23880_get_config,
	.reset = tps23880_port_reset,
	.set_power_limit = tps23880_port_set_power_limit,
	.get_power_limit = tps23880_port_get_power_limit,
	.enable_classify =  tps23880_port_enable_classify,
	.enable_detect = tps23880_port_enable_detect,
};

static int tps23880_voltage(struct device *dev)
{
	struct pse_port_device *port = to_ppd(dev);
	uint32_t voltage =  0;
	uint32_t channel_voltage =  0;
	int res = 0;
	int i = 0;

	/* Since each port is composed of two channels, each channel can have it's
	 * own voltage and is independent of the other channel. The only product we've
	 * got with a BT PSE is Ironman, and on that product, every port has two
	 * channels; therefore we'll simply take the maximum of either channel and
	 * report that as the port voltage
	 */

	for (i = 0; i < 2; i++) {
		res = tps23880_read_channel_register(port->channel[i], TPS23880_VOLTAGE_BASE, 4, tps23880_read_register_word);
		if (res < 0) {
			dev_warn(dev, "Failed to read channel register in %s, res=%d\n", __func__, res);
			res = 0;
		}
		channel_voltage =  ((uint32_t)(res & TPS23880_VOLTAGE_MASK) * 3662); /* uV */
		if (channel_voltage > voltage) {
			voltage = channel_voltage;
		}
	}

	return (int) (voltage/1000); /* Scale from uV to mV */
}
static int tps23880_current(struct device *dev)
{
	struct pse_port_device *port = to_ppd(dev);
	uint32_t c = 0;
	int res = 0;
	int i = 0;

	for (i = 0; i < 2; i++) {
		res = tps23880_read_channel_register(port->channel[i], TPS23880_CURRENT_BASE, 4, tps23880_read_register_word);
		if (res < 0) {
			dev_info(dev, "Failed to read channel register in %s, res=%d\n", __func__, res);
			res = 0;
		}
		c += ((uint32_t)(res & TPS23880_CURRENT_MASK) * 7019); /* 70.19 uA/bit */
	}

	/* We don't average this because the current is the sum of both channels.
	 * We do /100 because 70.19uA/bit but we multiplied by 7019
	 */

	return (int)(c/100);
}


static int tps23880_update_detection(struct device *dev)
{
	struct pse_port_device *port = to_ppd(dev);

	tps23880_read_discovery_results(port);
	return 0;
}

static int tps23880_apply_power(struct device *dev, unsigned enabled)
{
	struct pse_port_device *port = to_ppd(dev);
	struct tps23880_device *tdev = port_tps23880_device(port);
	uint8_t data = 0;
	uint8_t i = 0;
	struct power_channel *channel;

	dev_dbg(&port->dev, " in %s\n", __func__);
	if (enabled) {
		for (i = 0 ; i < 2; i++) {
			channel = port->channel[i];
			if (channel->detect_result == DETECT_POWERED_DEVICE && channel->class_result != CLASS_INVALID) {
				data |= TPS23880_PWRPB_ON(channel_index(channel));
				dev_info(&port->dev, "Setting the pwron bit for channel %d\n", channel_index(channel));
			}
		}
	} else {
		data = TPS23880_PWRPB_OFF(channel_index(port->channel[0])) | TPS23880_PWRPB_OFF(channel_index(port->channel[1]));
	}
	dev_dbg(&port->dev, "writing 0x%02X to %s port %d\n", data, enabled ? "turn on" : "turn off", port->id);
	return tps23880_write_register(tdev, TPS23880_PWRPB, data);
}

static int tps23880_pd_powered(struct device *dev)
{
	struct pse_port_device *port = to_pse_port_device(dev);
	struct tps23880_device *tdev = port_tps23880_device(port);
	int res = 0;
	uint8_t pwr_gd;

	res = tps23880_read_register(tdev, TPS23880_STATPWR);
	if (res < 0) {
		dev_err(&port->dev, "Failed to read register 0x10 in %s, i2c_smbus_read_byte_data returned %d\n", __func__, res);
		return res;
	}
	pwr_gd = (res & (TPS23880_STATPWR_PG(channel_index(port->channel[0])) | TPS23880_STATPWR_PG(channel_index(port->channel[1]))));
	if (port->dual_signature)
		return (pwr_gd == (TPS23880_STATPWR_PG(channel_index(port->channel[0])) | TPS23880_STATPWR_PG(channel_index(port->channel[1]))));

	return !!(pwr_gd);
}

static int tps23880_configure_port(struct device *dev, struct pse_port_config *config)
{
	dev_dbg(dev, " in %s\n", __func__);
	return 0;
}
static int tps23880_port_enable_classify(struct device *dev, int enable)
{
	struct pse_port_device *port = to_pse_port_device(dev);
	struct tps23880_device *tdev = port_tps23880_device(port);
	uint8_t data = 0x00;

	data = TPS23880_DETENA_CLS((channel_index(port->channel[0]))) | TPS23880_DETENA_CLS(channel_index(port->channel[1]));
	dev_dbg(&port->dev, "in %s, operating on port->port-id=%d (port->id=%d) using  data=0x%02X\n", __func__, port->port_id, port->id, data);
	if (enable) {
		dev_dbg(&port->dev, " Enabling classification for port %d\n", port->port_id);
		return tps23880_write_register(tdev, TPS23880_DETENA_PB, data);
	}

	return tps23880_read_modify_write_byte(tdev, TPS23880_DETENA, data, 0); /*Data is acting as the "mask" here because we want to set zeros */
}
static int tps23880_port_enable_detect(struct device *dev, int enable)
{
	struct pse_port_device *port = to_ppd(dev);
	struct i2c_client *client =  container_of(dev->parent, struct i2c_client, dev);
	struct tps23880_device *tdev = i2c_get_clientdata(client);
	uint8_t data = 0x00;

	data = TPS23880_DETENA_DET((channel_index(port->channel[0]))) | TPS23880_DETENA_DET(channel_index(port->channel[1]));

	if (enable) {
		dev_dbg(&port->dev, " Enabling detection for port%d by writing 0x%02X to 0x%02X\n", port->id, data, TPS23880_DETENA_PB);
		return tps23880_write_register(tdev, TPS23880_DETENA_PB, data);
	}

	dev_dbg(&port->dev, " Disabling detection for port%d by writing 0x%02X to 0x%02X\n", port->id, data, TPS23880_DETENA);
	return tps23880_read_modify_write_byte(tdev, TPS23880_DETENA, data, 0);
}

int tps23880_get_config(struct device *dev, struct pse_port_config *config)
{
	struct pse_port_device *port = to_pse_port_device(dev);

	dev_dbg(dev, " in %s\n", __func__);

	config->enabled =  port->enabled;
	config->managed = 1;
	config->disconnect_event = (tps23880_read_register(port_tps23880_device(port), TPS23880_DISENA) & (TPS23880_DISENA_DC(channel_index(port->channel[0])) | TPS23880_DISENA_DC(channel_index(port->channel[1])))) ? 1 : 0;

	config->detect_enable = (tps23880_read_register(port_tps23880_device(port), TPS23880_DETENA) & (TPS23880_DETENA_DET(channel_index(port->channel[0])) | TPS23880_DETENA_DET(channel_index(port->channel[1])))) ? 1 : 0;
	config->classify_enable = (tps23880_read_register(port_tps23880_device(port), TPS23880_DETENA) & (TPS23880_DETENA_CLS(channel_index(port->channel[0])) | TPS23880_DETENA_CLS(channel_index(port->channel[1])))) ? 1 : 0;
	config->legacy_enable = 0;
	config->current_limit = 0;
	return 0;

}
static int tps23880_port_get_power_limit(struct device *dev)
{
	dev_dbg(dev, " in %s\n", __func__);
	struct pse_port_device * port = to_ppd(dev);
	int power_limit = 0;

	power_limit = tps23880_read_register(port_tps23880_device(port), TPS23880_4P_POLICE(channel_index(port->channel[0])));

	dev_info(dev, "in %s, read 0x%02X = %d mW\n", __func__, power_limit, (power_limit*1000)/2);
	return (1000*power_limit)/2;
}

static int tps23880_port_set_power_limit(struct device *dev, int power_limit)
{
	struct pse_port_device * port = to_ppd(dev);
	uint8_t police_limit = (uint8_t) ((power_limit * 2)/1000);
	dev_info(dev, "Setting the power limit to %d mW, writing 0x%02X\n", power_limit, police_limit);
	tps23880_write_register(port_tps23880_device(port), TPS23880_2P_POLICE(channel_index(port->channel[0])), police_limit);

	tps23880_write_register(port_tps23880_device(port), TPS23880_4P_POLICE(channel_index(port->channel[0])), police_limit);
	return 0;
}


static int tps23880_port_reset(struct device *dev)
{
	struct pse_port_device *port = to_ppd(dev);
	int ret = 0;

	/* Tickle the reset push-button register for this port*/
	/* And then re-init the port */

	pse_port_reset(port);
	ret = tps23880_port_init(port);

	if (ret < 0) {
		dev_warn(dev, "Port init has failed\n");
		goto reset_unlock_ret;
	}

	ret = port->ops->enable_detect(dev, 1);
	if (ret < 0) {
		dev_warn(dev, "Failed to enable detection\n");
		goto reset_unlock_ret;
	}

	ret = port->ops->enable_classify(dev, 1);
	if (ret < 0) {
		dev_warn(dev, "Failed to enable classification\n");
		goto reset_unlock_ret;
	}

reset_unlock_ret:
	return ret;
}