/*
 * Copyright (c) 2016 Intel Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <errno.h>

#include <device.h>
#include <init.h>
#include <drivers/ioapic.h>
#include <counter.h>
#include <power.h>
#include <soc.h>

#include "qm_aon_counters.h"
#include "qm_isr.h"

static void aonpt_int_callback(void *user_data);

static counter_callback_t user_cb;

struct aon_data {
#ifdef CONFIG_AON_API_REENTRANCY
	struct k_sem sem;
#endif
#ifdef CONFIG_DEVICE_POWER_MANAGEMENT
	uint32_t device_power_state;
#endif
};

#define AONPT_HAS_CONTEXT_DATA \
	(CONFIG_AON_API_REENTRANCY || CONFIG_DEVICE_POWER_MANAGEMENT)

#if AONPT_HAS_CONTEXT_DATA
static struct aon_data aonpt_context;
#define AONPT_CONTEXT (&aonpt_context)
#else
#define AONPT_CONTEXT (NULL)
#endif

#ifdef CONFIG_AON_API_REENTRANCY
static const int reentrancy_protection = 1;
#define RP_GET(dev) (&((struct aon_data *)(dev->driver_data))->sem)
#else
static const int reentrancy_protection;
#define RP_GET(dev) (NULL)
#endif

static void aon_reentrancy_init(struct device *dev)
{
	if (!reentrancy_protection) {
		return;
	}

	k_sem_init(RP_GET(dev), 0, UINT_MAX);
	k_sem_give(RP_GET(dev));
}

static void aon_critical_region_start(struct device *dev)
{
	if (!reentrancy_protection) {
		return;
	}

	k_sem_take(RP_GET(dev), K_FOREVER);
}

static void aon_critical_region_end(struct device *dev)
{
	if (!reentrancy_protection) {
		return;
	}

	k_sem_give(RP_GET(dev));
}

static int aon_timer_qmsi_start(struct device *dev)
{
	qm_aonpt_config_t qmsi_cfg;
	int result = 0;

	user_cb = NULL;

	qmsi_cfg.callback = NULL;
	qmsi_cfg.int_en = false;
	/* AONPT is a countdown timer. So, set the initial value to
	 * the maximum value.
	 */
	qmsi_cfg.count = 0xffffffff;
	qmsi_cfg.callback_data = NULL;

	aon_critical_region_start(dev);
	if (qm_aonpt_set_config(QM_AONC_0, &qmsi_cfg)) {
		result = -EIO;
	}
	aon_critical_region_end(dev);

	return result;
}

static int aon_timer_qmsi_stop(struct device *dev)
{
	qm_aonpt_config_t qmsi_cfg;

	qmsi_cfg.callback = NULL;
	qmsi_cfg.int_en = false;
	qmsi_cfg.count = 0;
	qmsi_cfg.callback_data = NULL;

	aon_critical_region_start(dev);
	qm_aonpt_set_config(QM_AONC_0, &qmsi_cfg);
	aon_critical_region_end(dev);

	return 0;
}

static uint32_t aon_timer_qmsi_read(void)
{
	uint32_t value;

	qm_aonpt_get_value(QM_AONC_0, &value);

	return value;
}

static int aon_timer_qmsi_set_alarm(struct device *dev,
				    counter_callback_t callback,
				    uint32_t count, void *user_data)
{
	qm_aonpt_config_t qmsi_cfg;
	int result = 0;

	/* Check if timer has been started */
	if (QM_AONC[QM_AONC_0].aonpt_cfg == 0) {
		return -ENOTSUP;
	}

	user_cb = callback;

	qmsi_cfg.callback = aonpt_int_callback;
	qmsi_cfg.int_en = true;
	qmsi_cfg.count = count;
	qmsi_cfg.callback_data = user_data;

	aon_critical_region_start(dev);
	if (qm_aonpt_set_config(QM_AONC_0, &qmsi_cfg)) {
		user_cb = NULL;
		result = -EIO;
	}
	aon_critical_region_end(dev);

	return result;
}

static uint32_t aon_timer_qmsi_get_pending_int(struct device *dev)
{
	return QM_AONC[QM_AONC_0].aonpt_stat;
}

static const struct counter_driver_api aon_timer_qmsi_api = {
	.start = aon_timer_qmsi_start,
	.stop = aon_timer_qmsi_stop,
	.read = aon_timer_qmsi_read,
	.set_alarm = aon_timer_qmsi_set_alarm,
	.get_pending_int = aon_timer_qmsi_get_pending_int,
};

#ifdef CONFIG_DEVICE_POWER_MANAGEMENT
static void aonpt_qmsi_set_power_state(struct device *dev, uint32_t power_state)
{
	struct aon_data *context = dev->driver_data;

	context->device_power_state = power_state;
}

static uint32_t aonpt_qmsi_get_power_state(struct device *dev)
{
	struct aon_data *context = dev->driver_data;

	return context->device_power_state;
}

#ifdef CONFIG_SYS_POWER_DEEP_SLEEP
static int aonpt_suspend_device(struct device *dev)
{
	aonpt_qmsi_set_power_state(dev, DEVICE_PM_SUSPEND_STATE);

	return 0;
}

static int aonpt_resume_device_from_suspend(struct device *dev)
{
	uint32_t int_aonpt_mask;

	/* The interrupt router registers are sticky and retain their
	 * values across warm resets, so we don't need to save them.
	 * But for wake capable peripherals, if their interrupts are
	 * configured to be edge sensitive, the wake event will be lost
	 * by the time the interrupt controller is reconfigured, while
	 * the interrupt is still pending. By masking and unmasking again
	 * the corresponding routing register, the interrupt is forwared
	 * to the core and the ISR will be serviced as expected.
	 */
	int_aonpt_mask = QM_INTERRUPT_ROUTER->aonpt_0_int_mask;
	QM_INTERRUPT_ROUTER->aonpt_0_int_mask = 0xFFFFFFFF;
	QM_INTERRUPT_ROUTER->aonpt_0_int_mask = int_aonpt_mask;

	aonpt_qmsi_set_power_state(dev, DEVICE_PM_ACTIVE_STATE);

	return 0;
}
#endif

/*
* Implements the driver control management functionality
* the *context may include IN data or/and OUT data
*/
static int aonpt_qmsi_device_ctrl(struct device *dev, uint32_t ctrl_command,
				  void *context)
{
	if (ctrl_command == DEVICE_PM_SET_POWER_STATE) {
#ifdef CONFIG_SYS_POWER_DEEP_SLEEP
		if (*((uint32_t *)context) == DEVICE_PM_SUSPEND_STATE) {
			return aonpt_suspend_device(dev);
		} else if (*((uint32_t *)context) == DEVICE_PM_ACTIVE_STATE) {
			return aonpt_resume_device_from_suspend(dev);
		}
#endif
	} else if (ctrl_command == DEVICE_PM_GET_POWER_STATE) {
		*((uint32_t *)context) = aonpt_qmsi_get_power_state(dev);
		return 0;
	}

	return 0;
}
#else
#define aonpt_qmsi_set_power_state(...)
#endif

static int aon_timer_init(struct device *dev)
{
	dev->driver_api = &aon_timer_qmsi_api;

	user_cb = NULL;

	IRQ_CONNECT(IRQ_GET_NUMBER(QM_IRQ_AONPT_0_INT),
		    CONFIG_AON_TIMER_IRQ_PRI, qm_aonpt_0_isr, NULL,
		    IOAPIC_EDGE | IOAPIC_HIGH);

	irq_enable(IRQ_GET_NUMBER(QM_IRQ_AONPT_0_INT));

	QM_IR_UNMASK_INTERRUPTS(QM_INTERRUPT_ROUTER->aonpt_0_int_mask);

	aon_reentrancy_init(dev);

	aonpt_qmsi_set_power_state(dev, DEVICE_PM_ACTIVE_STATE);

	return 0;
}


DEVICE_DEFINE(aon_timer, CONFIG_AON_TIMER_QMSI_DEV_NAME, aon_timer_init,
	      aonpt_qmsi_device_ctrl, AONPT_CONTEXT, NULL, POST_KERNEL,
	      CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
	      &aon_timer_qmsi_api);

static void aonpt_int_callback(void *user_data)
{
	if (user_cb) {
		(*user_cb)(DEVICE_GET(aon_timer), user_data);
	}
}