/*
 * \file
 *
 * \brief SAM Direct Memory Access Controller Driver
 *
 * Copyright (C) 2014-2015 Atmel Corporation. All rights reserved.
 *
 * \asf_license_start
 *
 * \page License
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. The name of Atmel may not be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * 4. This software may only be redistributed and used in connection with an
 *    Atmel microcontroller product.
 *
 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * \asf_license_stop
 *
 */
/*
 * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
 */

#include <string.h>
#include "dma.h"
#include "clock.h"
#include "system_interrupt.h"

struct _dma_module {
    volatile bool _dma_init;
    volatile uint32_t allocated_channels;
    uint8_t free_channels;
};

struct _dma_module _dma_inst = {
    ._dma_init = false,
    .allocated_channels = 0,
    .free_channels = CONF_MAX_USED_CHANNEL_NUM,
};

/** Maximum retry counter for resuming a job transfer. */
#define MAX_JOB_RESUME_COUNT    10000

/** DMA channel mask. */
#define DMA_CHANNEL_MASK   (0x1f)

COMPILER_ALIGNED(16)
DmacDescriptor descriptor_section[CONF_MAX_USED_CHANNEL_NUM] SECTION_DMAC_DESCRIPTOR;

/** Initial write back memory section. */
COMPILER_ALIGNED(16)
static DmacDescriptor _write_back_section[CONF_MAX_USED_CHANNEL_NUM] SECTION_DMAC_DESCRIPTOR;

/** Internal DMA resource pool. */
static struct dma_resource* _dma_active_resource[CONF_MAX_USED_CHANNEL_NUM];

/* DMA channel interrup flag. */
uint8_t g_chan_interrupt_flag[CONF_MAX_USED_CHANNEL_NUM]= {0};

/**
 * \brief Find a free channel for a DMA resource.
 *
 * Find a channel for the requested DMA resource.
 *
 * \return Status of channel allocation.
 * \retval DMA_INVALID_CHANNEL  No channel available
 * \retval count          Allocated channel for the DMA resource
 */
static uint8_t _dma_find_first_free_channel_and_allocate(void)
{
    uint8_t count;
    uint32_t tmp;
    bool allocated = false;

    system_interrupt_enter_critical_section();

    tmp = _dma_inst.allocated_channels;

    for (count = 0; count < CONF_MAX_USED_CHANNEL_NUM; ++count) {
        if (!(tmp & 0x00000001)) {
            /* If free channel found, set as allocated and return
             *number */

            _dma_inst.allocated_channels |= 1 << count;
            _dma_inst.free_channels--;
            allocated = true;

            break;
        }

        tmp = tmp >> 1;
    }

    system_interrupt_leave_critical_section();

    if (!allocated) {
        return DMA_INVALID_CHANNEL;
    } else {
        return count;
    }
}

/**
 * \brief Release an allocated DMA channel.
 *
 * \param[in]  channel  Channel id to be released
 *
 */
static void _dma_release_channel(uint8_t channel)
{
    _dma_inst.allocated_channels &= ~(1 << channel);
    _dma_inst.free_channels++;
}

/**
 * \brief Configure the DMA resource.
 *
 * \param[in]  dma_resource Pointer to a DMA resource instance
 * \param[out] resource_config Configurations of the DMA resource
 *
 */
static void _dma_set_config(struct dma_resource *resource,
                            struct dma_resource_config *resource_config)
{
    Assert(resource);
    Assert(resource_config);
    uint32_t temp_CHCTRLB_reg;
    system_interrupt_enter_critical_section();

    /** Select the DMA channel and clear software trigger */
    DMAC->CHID.reg = DMAC_CHID_ID(resource->channel_id);
    DMAC->SWTRIGCTRL.reg &= (uint32_t)(~(1 << resource->channel_id));

    temp_CHCTRLB_reg = DMAC_CHCTRLB_LVL(resource_config->priority) | \
                       DMAC_CHCTRLB_TRIGSRC(resource_config->peripheral_trigger) | \
                       DMAC_CHCTRLB_TRIGACT(resource_config->trigger_action);


    if(resource_config->event_config.input_action) {
        temp_CHCTRLB_reg |= DMAC_CHCTRLB_EVIE | DMAC_CHCTRLB_EVACT(
                                resource_config->event_config.input_action);
    }

    /** Enable event output, the event output selection is configured in
     * each transfer descriptor  */
    if (resource_config->event_config.event_output_enable) {
        temp_CHCTRLB_reg |= DMAC_CHCTRLB_EVOE;
    }

    /* Write config to CTRLB register */
    DMAC->CHCTRLB.reg = temp_CHCTRLB_reg;



    system_interrupt_leave_critical_section();
}

/**
 * \brief DMA interrupt service routine.
 *
 */
void DMAC_Handler( void )
{
    uint8_t active_channel;
    struct dma_resource *resource;
    uint8_t isr;
    uint32_t write_size;
    uint32_t total_size;

    system_interrupt_enter_critical_section();

    /* Get Pending channel */
    active_channel =  DMAC->INTPEND.reg & DMAC_INTPEND_ID_Msk;

    Assert(_dma_active_resource[active_channel]);

    /* Get active DMA resource based on channel */
    resource = _dma_active_resource[active_channel];

    /* Select the active channel */
    DMAC->CHID.reg = DMAC_CHID_ID(resource->channel_id);
    isr = DMAC->CHINTFLAG.reg;

    /* Calculate block transfer size of the DMA transfer */
    total_size = descriptor_section[resource->channel_id].BTCNT.reg;
    write_size = _write_back_section[resource->channel_id].BTCNT.reg;
    resource->transfered_size = total_size - write_size;

    /* DMA channel interrupt handler */
    if (isr & DMAC_CHINTENCLR_TERR) {
        /* Clear transfer error flag */
        DMAC->CHINTFLAG.reg = DMAC_CHINTENCLR_TERR;

        /* Set I/O ERROR status */
        resource->job_status = STATUS_ERR_IO;

        /* Execute the callback function */
        if ((resource->callback_enable & (1<<DMA_CALLBACK_TRANSFER_ERROR)) &&
                (resource->callback[DMA_CALLBACK_TRANSFER_ERROR])) {
            resource->callback[DMA_CALLBACK_TRANSFER_ERROR](resource);
        }
    } else if (isr & DMAC_CHINTENCLR_TCMPL) {
        /* Clear the transfer complete flag */
        DMAC->CHINTFLAG.reg = DMAC_CHINTENCLR_TCMPL;

        /* Set job status */
        resource->job_status = STATUS_OK;

        /* Execute the callback function */
        if ((resource->callback_enable & (1 << DMA_CALLBACK_TRANSFER_DONE)) &&
                (resource->callback[DMA_CALLBACK_TRANSFER_DONE])) {
            resource->callback[DMA_CALLBACK_TRANSFER_DONE](resource);
        }
    } else if (isr & DMAC_CHINTENCLR_SUSP) {
        /* Clear channel suspend flag */
        DMAC->CHINTFLAG.reg = DMAC_CHINTENCLR_SUSP;

        /* Set job status */
        resource->job_status = STATUS_SUSPEND;

        /* Execute the callback function */
        if ((resource->callback_enable & (1 << DMA_CALLBACK_CHANNEL_SUSPEND)) &&
                (resource->callback[DMA_CALLBACK_CHANNEL_SUSPEND])) {
            resource->callback[DMA_CALLBACK_CHANNEL_SUSPEND](resource);
        }
    }

    system_interrupt_leave_critical_section();
}

/**
 * \brief Initializes config with predefined default values.
 *
 * This function will initialize a given DMA configuration structure to
 * a set of known default values. This function should be called on
 * any new instance of the configuration structure before being
 * modified by the user application.
 *
 * The default configuration is as follows:
 *  \li Software trigger is used as the transfer trigger
 *  \li Priority level 0
 *  \li Only software/event trigger
 *  \li Requires a trigger for each transaction
 *  \li No event input /output
 *  \li DMA channel is disabled during sleep mode (if has the feature)
 * \param[out] config Pointer to the configuration
 *
 */
void dma_get_config_defaults(struct dma_resource_config *config)
{
    Assert(config);
    /* Set as priority 0 */
    config->priority = DMA_PRIORITY_LEVEL_0;
    /* Only software/event trigger */
    config->peripheral_trigger = 0;
    /* Transaction trigger */
    config->trigger_action = DMA_TRIGGER_ACTON_TRANSACTION;

    /* Event configurations, no event input/output */
    config->event_config.input_action = DMA_EVENT_INPUT_NOACT;
    config->event_config.event_output_enable = false;
#ifdef FEATURE_DMA_CHANNEL_STANDBY
    config->run_in_standby = false;
#endif
}

/**
 * \brief Allocate a DMA with configurations.
 *
 * This function will allocate a proper channel for a DMA transfer request.
 *
 * \param[in,out]  dma_resource Pointer to a DMA resource instance
 * \param[in] transfer_config Configurations of the DMA transfer
 *
 * \return Status of the allocation procedure.
 *
 * \retval STATUS_OK The DMA resource was allocated successfully
 * \retval STATUS_ERR_NOT_FOUND DMA resource allocation failed
 */
enum status_code dma_allocate(struct dma_resource *resource,
                              struct dma_resource_config *config)
{
    uint8_t new_channel;

    Assert(resource);

    system_interrupt_enter_critical_section();

    if (!_dma_inst._dma_init) {
        /* Initialize clocks for DMA */
#if (SAML21) || (SAMC20) || (SAMC21)
        system_ahb_clock_set_mask(MCLK_AHBMASK_DMAC);
#else
        system_ahb_clock_set_mask(PM_AHBMASK_DMAC);
        system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBB,
                                  PM_APBBMASK_DMAC);
#endif

        /* Perform a software reset before enable DMA controller */
        DMAC->CTRL.reg &= ~DMAC_CTRL_DMAENABLE;
        DMAC->CTRL.reg = DMAC_CTRL_SWRST;

        /* Setup descriptor base address and write back section base
         * address */
        DMAC->BASEADDR.reg = (uint32_t)descriptor_section;
        DMAC->WRBADDR.reg = (uint32_t)_write_back_section;

        /* Enable all priority level at the same time */
        DMAC->CTRL.reg = DMAC_CTRL_DMAENABLE | DMAC_CTRL_LVLEN(0xf);

        _dma_inst._dma_init = true;
    }

    /* Find the proper channel */
    new_channel = _dma_find_first_free_channel_and_allocate();

    /* If no channel available, return not found */
    if (new_channel == DMA_INVALID_CHANNEL) {
        system_interrupt_leave_critical_section();

        return STATUS_ERR_NOT_FOUND;
    }

    /* Set the channel */
    resource->channel_id = new_channel;

    /** Perform a reset for the allocated channel */
    DMAC->CHID.reg = DMAC_CHID_ID(resource->channel_id);
    DMAC->CHCTRLA.reg &= ~DMAC_CHCTRLA_ENABLE;
    DMAC->CHCTRLA.reg = DMAC_CHCTRLA_SWRST;

#ifdef FEATURE_DMA_CHANNEL_STANDBY
    if(config->run_in_standby) {
        DMAC->CHCTRLA.reg |= DMAC_CHCTRLA_RUNSTDBY;
    }
#endif

    /** Configure the DMA control,channel registers and descriptors here */
    _dma_set_config(resource, config);

    resource->descriptor = NULL;

    /* Log the DMA resource into the internal DMA resource pool */
    _dma_active_resource[resource->channel_id] = resource;

    system_interrupt_leave_critical_section();

    return STATUS_OK;
}

/**
 * \brief Free an allocated DMA resource.
 *
 * This function will free an allocated DMA resource.
 *
 * \param[in,out] resource Pointer to the DMA resource
 *
 * \return Status of the free procedure.
 *
 * \retval STATUS_OK The DMA resource was freed successfully
 * \retval STATUS_BUSY The DMA resource was busy and can't be freed
 * \retval STATUS_ERR_NOT_INITIALIZED DMA resource was not initialized
 */
enum status_code dma_free(struct dma_resource *resource)
{
    Assert(resource);
    Assert(resource->channel_id != DMA_INVALID_CHANNEL);

    system_interrupt_enter_critical_section();

    /* Check if channel is busy */
    if (dma_is_busy(resource)) {
        system_interrupt_leave_critical_section();
        return STATUS_BUSY;
    }

    /* Check if DMA resource was not allocated */
    if (!(_dma_inst.allocated_channels & (1 << resource->channel_id))) {
        system_interrupt_leave_critical_section();
        return STATUS_ERR_NOT_INITIALIZED;
    }

    /* Release the DMA resource */
    _dma_release_channel(resource->channel_id);

    /* Reset the item in the DMA resource pool */
    _dma_active_resource[resource->channel_id] = NULL;

    system_interrupt_leave_critical_section();

    return STATUS_OK;
}

/**
 * \brief Start a DMA transfer.
 *
 * This function will start a DMA transfer through an allocated DMA resource.
 *
 * \param[in,out] resource Pointer to the DMA resource
 *
 * \return Status of the transfer start procedure.
 *
 * \retval STATUS_OK The transfer was started successfully
 * \retval STATUS_BUSY The DMA resource was busy and the transfer was not started
 * \retval STATUS_ERR_INVALID_ARG Transfer size is 0 and transfer was not started
 */
enum status_code dma_start_transfer_job(struct dma_resource *resource)
{
    Assert(resource);
    Assert(resource->channel_id != DMA_INVALID_CHANNEL);

    system_interrupt_enter_critical_section();

    /* Check if resource was busy */
    if (resource->job_status == STATUS_BUSY) {
        system_interrupt_leave_critical_section();
        return STATUS_BUSY;
    }

    /* Check if transfer size is valid */
    if (resource->descriptor->BTCNT.reg == 0) {
        system_interrupt_leave_critical_section();
        return STATUS_ERR_INVALID_ARG;
    }

    /* Enable DMA interrupt */
    system_interrupt_enable(SYSTEM_INTERRUPT_MODULE_DMA);

    /* Set the interrupt flag */
    DMAC->CHID.reg = DMAC_CHID_ID(resource->channel_id);
    DMAC->CHINTENSET.reg = (DMAC_CHINTENSET_MASK & g_chan_interrupt_flag[resource->channel_id]);
    /* Set job status */
    resource->job_status = STATUS_BUSY;

    /* Set channel x descriptor 0 to the descriptor base address */
    memcpy(&descriptor_section[resource->channel_id], resource->descriptor,
           sizeof(DmacDescriptor));

    /* Enable the transfer channel */
    DMAC->CHCTRLA.reg |= DMAC_CHCTRLA_ENABLE;

    system_interrupt_leave_critical_section();

    return STATUS_OK;
}

/**
 * \brief Abort a DMA transfer.
 *
 * This function will abort a DMA transfer. The DMA channel used for the DMA
 * resource will be disabled.
 * The block transfer count will be also calculated and written to the DMA
 * resource structure.
 *
 * \note The DMA resource will not be freed after calling this function.
 *       The function \ref dma_free() can be used to free an allocated resource.
 *
 * \param[in,out] resource Pointer to the DMA resource
 *
 */
void dma_abort_job(struct dma_resource *resource)
{
    uint32_t write_size;
    uint32_t total_size;

    Assert(resource);
    Assert(resource->channel_id != DMA_INVALID_CHANNEL);

    system_interrupt_enter_critical_section();

    DMAC->CHID.reg = DMAC_CHID_ID(resource->channel_id);
    DMAC->CHCTRLA.reg = 0;

    system_interrupt_leave_critical_section();

    /* Get transferred size */
    total_size = descriptor_section[resource->channel_id].BTCNT.reg;
    write_size = _write_back_section[resource->channel_id].BTCNT.reg;
    resource->transfered_size = total_size - write_size;

    resource->job_status = STATUS_ABORTED;
}

/**
 * \brief Suspend a DMA transfer.
 *
 * This function will request to suspend the transfer of the DMA resource.
 * The channel is kept enabled, can receive transfer triggers (the transfer
 * pending bit will be set), but will be removed from the arbitration scheme.
 * The channel operation can be resumed by calling \ref dma_resume_job().
 *
 * \note This function sets the command to suspend the DMA channel
 * associated with a DMA resource. The channel suspend interrupt flag
 * indicates whether the transfer is truly suspended.
 *
 * \param[in] resource Pointer to the DMA resource
 *
 */
void dma_suspend_job(struct dma_resource *resource)
{
    Assert(resource);
    Assert(resource->channel_id != DMA_INVALID_CHANNEL);

    system_interrupt_enter_critical_section();

    /* Select the channel */
    DMAC->CHID.reg = DMAC_CHID_ID(resource->channel_id);

    /* Send the suspend request */
    DMAC->CHCTRLB.reg |= DMAC_CHCTRLB_CMD_SUSPEND;

    system_interrupt_leave_critical_section();
}

/**
 * \brief Resume a suspended DMA transfer.
 *
 * This function try to resume a suspended transfer of a DMA resource.
 *
 * \param[in] resource Pointer to the DMA resource
 *
 */
void dma_resume_job(struct dma_resource *resource)
{
    uint32_t bitmap_channel;
    uint32_t count = 0;

    Assert(resource);
    Assert(resource->channel_id != DMA_INVALID_CHANNEL);

    /* Get bitmap of the allocated DMA channel */
    bitmap_channel = (1 << resource->channel_id);

    /* Check if channel was suspended */
    if (resource->job_status != STATUS_SUSPEND) {
        return;
    }

    system_interrupt_enter_critical_section();

    /* Send resume request */
    DMAC->CHID.reg = DMAC_CHID_ID(resource->channel_id);
    DMAC->CHCTRLB.reg |= DMAC_CHCTRLB_CMD_RESUME;

    system_interrupt_leave_critical_section();

    /* Check if transfer job resumed */
    for (count = 0; count < MAX_JOB_RESUME_COUNT; count++) {
        if ((DMAC->BUSYCH.reg & bitmap_channel) == bitmap_channel) {
            break;
        }
    }

    if (count < MAX_JOB_RESUME_COUNT) {
        /* Job resumed */
        resource->job_status = STATUS_BUSY;
    } else {
        /* Job resume timeout */
        resource->job_status = STATUS_ERR_TIMEOUT;
    }
}

/**
 * \brief Create a DMA transfer descriptor with configurations.
 *
 * This function will set the transfer configurations to the DMA transfer
 * descriptor.
 *
 * \param[in] descriptor Pointer to the DMA transfer descriptor
 * \param[in] config Pointer to the descriptor configuration structure
 *
 */
void dma_descriptor_create(DmacDescriptor* descriptor,
                           struct dma_descriptor_config *config)
{
    /* Set block transfer control */
    descriptor->BTCTRL.bit.VALID = config->descriptor_valid;
    descriptor->BTCTRL.bit.EVOSEL = config->event_output_selection;
    descriptor->BTCTRL.bit.BLOCKACT = config->block_action;
    descriptor->BTCTRL.bit.BEATSIZE = config->beat_size;
    descriptor->BTCTRL.bit.SRCINC = config->src_increment_enable;
    descriptor->BTCTRL.bit.DSTINC = config->dst_increment_enable;
    descriptor->BTCTRL.bit.STEPSEL = config->step_selection;
    descriptor->BTCTRL.bit.STEPSIZE = config->step_size;

    /* Set transfer size, source address and destination address */
    descriptor->BTCNT.reg = config->block_transfer_count;
    descriptor->SRCADDR.reg = config->source_address;
    descriptor->DSTADDR.reg = config->destination_address;

    /* Set next transfer descriptor address */
    descriptor->DESCADDR.reg = config->next_descriptor_address;
}

/**
 * \brief Add a DMA transfer descriptor to a DMA resource.
 *
 * This function will add a DMA transfer descriptor to a DMA resource.
 * If there was a transfer descriptor already allocated to the DMA resource,
 * the descriptor will be linked to the next descriptor address.
 *
 * \param[in] resource Pointer to the DMA resource
 * \param[in] descriptor Pointer to the transfer descriptor
 *
 * \retval STATUS_OK The descriptor is added to the DMA resource
 * \retval STATUS_BUSY The DMA resource was busy and the descriptor is not added
 */
enum status_code dma_add_descriptor(struct dma_resource *resource,
                                    DmacDescriptor* descriptor)
{
    DmacDescriptor* desc = resource->descriptor;

    if (resource->job_status == STATUS_BUSY) {
        return STATUS_BUSY;
    }

    /* Look up for an empty space for the descriptor */
    if (desc == NULL) {
        resource->descriptor = descriptor;
    } else {
        /* Looking for end of descriptor link */
        while(desc->DESCADDR.reg != 0) {
            desc = (DmacDescriptor*)(desc->DESCADDR.reg);
        }

        /* Set to the end of descriptor list */
        desc->DESCADDR.reg = (uint32_t)descriptor;
    }

    return STATUS_OK;
}