/*
FreeRTOS+TCP V2.0.11
Copyright (C) 2017 Amazon.com, Inc. or its affiliates.  All Rights Reserved.

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 http://aws.amazon.com/freertos
 http://www.FreeRTOS.org
*/

/* Standard includes. */
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "semphr.h"

/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_Sockets.h"
#include "FreeRTOS_IP_Private.h"
#include "NetworkBufferManagement.h"
#include "NetworkInterface.h"

#include "sam4e_xplained_pro.h"
#include "hr_gettime.h"
#include "conf_eth.h"
#include "ksz8851snl.h"
#include "ksz8851snl_reg.h"

/* Some files from the Atmel Software Framework */
#include <sysclk.h>
#include <pdc/pdc.h>
#include <spi/spi.h>

/*
	Sending a packet:

		1) Called by UP-task, add buffer to the TX-list:
			xNetworkInterfaceOutput()
				tx_buffers[ us_tx_head ] = pxNetworkBuffer;
				tx_busy[ us_tx_head ] = pdTRUE;
				us_tx_head++;

		2) Called by EMAC-Task: start SPI transfer
			ksz8851snl_update()
			if( ul_spi_pdc_status == SPI_PDC_IDLE )
			{
				if( ( tx_busy[ us_tx_tail ] != pdFALSE ) &&
					( us_pending_frame == 0 ) &&
					( ul_had_intn_interrupt == 0 ) )
				{
					// disable all interrupts.
					ksz8851_reg_write( REG_INT_MASK, 0 );
					Bring KSZ8851SNL_CSN_GPIO low
					ksz8851_fifo_write( pxNetworkBuffer->pucEthernetBuffer, xLength, xLength );
					ul_spi_pdc_status = SPI_PDC_TX_START;
					tx_cur_buffer = pxNetworkBuffer;
				}
			}
		3) Wait for SPI RXBUFF interrupt
			SPI_Handler()
				if( ul_spi_pdc_status == SPI_PDC_TX_START )
				{
					if( SPI_Status & SPI_SR_RXBUFF )
					{
						ul_spi_pdc_status = SPI_PDC_TX_COMPLETE;
					}
				}

		4) Called by EMAC-Task: finish SPI transfer
			ksz8851snl_update()
				if( ul_spi_pdc_status == SPI_PDC_TX_COMPLETE )
				{
					ul_spi_pdc_status = SPI_PDC_IDLE;
					Bring KSZ8851SNL_CSN_GPIO high
					// TX step12: disable TXQ write access.
					ksz8851_reg_clrbits( REG_RXQ_CMD, RXQ_START );
					// TX step12.1: enqueue frame in TXQ.
					ksz8851_reg_setbits( REG_TXQ_CMD, TXQ_ENQUEUE );

					// RX step13: enable INT_RX flag.
					ksz8851_reg_write( REG_INT_MASK, INT_RX );

					// Buffer sent, free the corresponding buffer and mark descriptor as owned by software.
					vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );

					tx_buffers[ us_tx_tail ] = NULL;
					tx_busy[ us_tx_tail ] = pdFALSE;
					us_tx_tail++
				}

	Receiving a packet:

		1) Wait for a INTN interrupt
			INTN_Handler()
				ul_had_intn_interrupt = 1
				vTaskNotifyGiveFromISR();	// Wake up the EMAC task

		2) Called by EMAC-Task: check for new fragments and start SPI transfer
			ksz8851snl_update()
				if( ul_spi_pdc_status == SPI_PDC_IDLE )
				{
					if( ( ul_had_intn_interrupt != 0 ) || ( us_pending_frame > 0 ) )
					{
						if( us_pending_frame == 0 )
						{
							us_pending_frame = ksz8851_reg_read(REG_RX_FRAME_CNT_THRES) >> 8;
							if( us_pending_frame == 0 )
							{
								break;
							}
						}
						// RX step2: disable all interrupts.
						ksz8851_reg_write( REG_INT_MASK, 0 );
						Check if there is a valid packet: REG_RX_FHR_STATUS
						Read the length of the next fragment: REG_RX_FHR_BYTE_CNT
						ul_spi_pdc_status = SPI_PDC_RX_START;
						gpio_set_pin_low(KSZ8851SNL_CSN_GPIO);
						// Start SPI data transfer
						ksz8851_fifo_read( pxNetworkBuffer->pucEthernetBuffer, xReadLength );
					}
				}

		3) Wait for SPI RXBUFF interrupt
			SPI_Handler()
			if( ul_spi_pdc_status == SPI_PDC_RX_START:
			{
				if( ( ulCurrentSPIStatus & SPI_SR_RXBUFF ) != 0 )
				{
					// Transfer complete, disable SPI RXBUFF interrupt.
					spi_disable_interrupt( KSZ8851SNL_SPI, SPI_IDR_RXBUFF );

					ul_spi_pdc_status = SPI_PDC_RX_COMPLETE;
				}
			}
		}

		4) Finish SPI transfer
			ksz8851snl_update()
				if( ul_spi_pdc_status == SPI_PDC_RX_COMPLETE )
				{
					ul_spi_pdc_status = SPI_PDC_IDLE;
					Bring KSZ8851SNL_CSN_GPIO high
					// RX step21: end RXQ read access.
					ksz8851_reg_clrbits(REG_RXQ_CMD, RXQ_START);
					// RX step22-23: update frame count to be read.
					us_pending_frame--
					// RX step24: enable INT_RX flag if transfer complete.
					if( us_pending_frame == 0 )
					{
						// Allow more RX interrupts.
						ksz8851_reg_write( REG_INT_MASK, INT_RX );
					}

					// Mark descriptor ready to be read.
					rx_ready[ rxHead ] = pdTRUE;
					rxHead++
				}
*/

#define PHY_REG_00_BMCR            0x00 // Basic mode control register
#define PHY_REG_01_BMSR            0x01 // Basic mode status register
#define PHY_REG_02_PHYSID1         0x02 // PHYS ID 1
#define PHY_REG_03_PHYSID2         0x03 // PHYS ID 2
#define PHY_REG_04_ADVERTISE       0x04 // Advertisement control reg
#define PHY_REG_05_LPA             0x05 // Link partner ability reg
#define	PHY_REG_06_ANER            0x06 //	6	RW		Auto-Negotiation Expansion Register
#define	PHY_REG_07_ANNPTR          0x07 //	7	RW		Auto-Negotiation Next Page TX
#define	PHY_REG_08_RESERVED0       0x08 // 0x08..0x0Fh	8-15	RW		RESERVED

#define BMSR_LINK_STATUS            0x0004  //!< Link status

#ifndef	PHY_LS_HIGH_CHECK_TIME_MS
	/* Check if the LinkSStatus in the PHY is still high after 15 seconds of not
	receiving packets. */
	#define PHY_LS_HIGH_CHECK_TIME_MS	15000
#endif

#ifndef	PHY_LS_LOW_CHECK_TIME_MS
	/* Check if the LinkSStatus in the PHY is still low every second. */
	#define PHY_LS_LOW_CHECK_TIME_MS	1000
#endif

/* Interrupt events to process.  Currently only the Rx event is processed
although code for other events is included to allow for possible future
expansion. */
#define EMAC_IF_RX_EVENT				1UL
#define EMAC_IF_TX_EVENT				2UL
#define EMAC_IF_ERR_EVENT				4UL
#define EMAC_IF_ALL_EVENT				( EMAC_IF_RX_EVENT | EMAC_IF_TX_EVENT | EMAC_IF_ERR_EVENT )

#define ETHERNET_CONF_PHY_ADDR	BOARD_GMAC_PHY_ADDR

#ifdef ipconfigHAS_TX_CRC_OFFLOADING
	#undef ipconfigHAS_TX_CRC_OFFLOADING
#endif
/* Override this define because the KSZ8851 is programmed to set all outgoing CRC's */
#define	ipconfigHAS_TX_CRC_OFFLOADING	1

#ifndef	EMAC_MAX_BLOCK_TIME_MS
	#define	EMAC_MAX_BLOCK_TIME_MS	100ul
#endif

/* Default the size of the stack used by the EMAC deferred handler task to 4x
the size of the stack used by the idle task - but allow this to be overridden in
FreeRTOSConfig.h as configMINIMAL_STACK_SIZE is a user definable constant. */
#ifndef configEMAC_TASK_STACK_SIZE
	#define configEMAC_TASK_STACK_SIZE ( 6 * configMINIMAL_STACK_SIZE )
#endif

#define SPI_PDC_IDLE			0
#define SPI_PDC_RX_START		1
#define SPI_PDC_TX_ERROR		2
#define SPI_PDC_RX_COMPLETE		3
#define SPI_PDC_TX_START		4
#define SPI_PDC_RX_ERROR		5
#define SPI_PDC_TX_COMPLETE		6

/**
 * ksz8851snl driver structure.
 */
typedef struct {
	/** Set to 1 when owner is software (ready to read), 0 for Micrel. */
	uint32_t rx_ready[MICREL_RX_BUFFERS];
	/** Set to 1 when owner is Micrel, 0 for software. */
	uint32_t tx_busy[MICREL_TX_BUFFERS];
	/** RX NetworkBufferDescriptor_t pointer list */
	NetworkBufferDescriptor_t *rx_buffers[MICREL_RX_BUFFERS];
	/** TX NetworkBufferDescriptor_t pointer list */
	NetworkBufferDescriptor_t *tx_buffers[MICREL_TX_BUFFERS];
	NetworkBufferDescriptor_t *tx_cur_buffer;

	/** Circular buffer head pointer for packet received. */
	uint32_t us_rx_head;
	/** Circular buffer tail pointer for packet to be read. */
	uint32_t us_rx_tail;
	/** Circular buffer head pointer by upper layer (buffer to be sent). */
	uint32_t us_tx_head;
	/** Circular buffer tail pointer incremented by handlers (buffer sent). */
	uint32_t us_tx_tail;

	uint32_t ul_total_tx;
	uint32_t ul_total_rx;
	uint32_t tx_space;

	/** Still experimental: hash table to allow certain multicast addresses. */
	uint16_t pusHashTable[ 4 ];

	/* ul_spi_pdc_status has "SPI_PDC_xxx" values. */
	volatile uint32_t ul_spi_pdc_status;

	/* ul_had_intn_interrupt becomes true within the INTN interrupt. */
	volatile uint32_t ul_had_intn_interrupt;

	uint16_t us_pending_frame;
} xKSZ8851_Device_t;

/* SPI PDC register base.
Declared in ASF\sam\components\ksz8851snl\ksz8851snl.c */
extern Pdc *g_p_spi_pdc;

/* Temporary buffer for PDC reception.
declared in ASF\sam\components\ksz8851snl\ksz8851snl.c */
extern uint8_t tmpbuf[1536];

COMPILER_ALIGNED(8)
static xKSZ8851_Device_t xMicrelDevice;

static TaskHandle_t xTransmitHandle;

/*-----------------------------------------------------------*/

/*
 * Wait a fixed time for the link status to indicate the network is up.
 */
static BaseType_t xGMACWaitLS( TickType_t xMaxTime );

/*
 * A deferred interrupt handler task that processes GMAC interrupts.
 */
static void prvEMACHandlerTask( void *pvParameters );

/*
 * Try to obtain an Rx packet from the hardware.
 */
static uint32_t prvEMACRxPoll( void );

static inline unsigned long ulReadMDIO( unsigned uAddress );

static void ksz8851snl_low_level_init( void );

static NetworkBufferDescriptor_t *ksz8851snl_low_level_input( void );

/*-----------------------------------------------------------*/

/* Bit map of outstanding ETH interrupt events for processing.  Currently only
the Rx interrupt is handled, although code is included for other events to
enable future expansion. */
static volatile uint32_t ulISREvents;

/* A copy of PHY register 1: 'PHY_REG_01_BMSR' */
static uint32_t ulPHYLinkStatus = 0;
static volatile BaseType_t xGMACSwitchRequired;

static void ksz8851snl_update( void );

static void ksz8851snl_rx_init( void );

static void ksz8851snl_tx_init( void );

/* Holds the handle of the task used as a deferred interrupt processor.  The
handle is used so direct notifications can be sent to the task for all EMAC/DMA
related interrupts. */
TaskHandle_t xEMACTaskHandle = NULL;


/*-----------------------------------------------------------*/

BaseType_t xNetworkInterfaceInitialise( void )
{
const TickType_t x5_Seconds = 5000UL;

	if( xEMACTaskHandle == NULL )
	{
		ksz8851snl_low_level_init();

		/* Wait at most 5 seconds for a Link Status in the PHY. */
		xGMACWaitLS( pdMS_TO_TICKS( x5_Seconds ) );

		/* The handler task is created at the highest possible priority to
		ensure the interrupt handler can return directly to it. */
		xTaskCreate( prvEMACHandlerTask, "KSZ8851", configEMAC_TASK_STACK_SIZE, NULL, configMAX_PRIORITIES - 1, &xEMACTaskHandle );
		configASSERT( xEMACTaskHandle );
	}

	/* When returning non-zero, the stack will become active and
    start DHCP (in configured) */
	ulPHYLinkStatus = ulReadMDIO( PHY_REG_01_BMSR );

	return ( ulPHYLinkStatus & BMSR_LINK_STATUS ) != 0;
}
/*-----------------------------------------------------------*/

BaseType_t xGetPhyLinkStatus( void )
{
BaseType_t xResult;

	/* This function returns true if the Link Status in the PHY is high. */
	if( ( ulPHYLinkStatus & BMSR_LINK_STATUS ) != 0 )
	{
		xResult = pdTRUE;
	}
	else
	{
		xResult = pdFALSE;
	}

	return xResult;
}
/*-----------------------------------------------------------*/

BaseType_t xNetworkInterfaceOutput( NetworkBufferDescriptor_t * const pxNetworkBuffer, BaseType_t bReleaseAfterSend )
{
BaseType_t xResult = pdFALSE;
int txHead = xMicrelDevice.us_tx_head;

	/* Make sure the next descriptor is free. */
	if( xMicrelDevice.tx_busy[ txHead ] != pdFALSE )
	{
		/* All TX buffers busy. */
	}
	else if( ( ulPHYLinkStatus & BMSR_LINK_STATUS ) == 0 )
	{
		/* Output: LS low. */
	}
	else
	{
		/* Pass the packet. */
		xMicrelDevice.tx_buffers[ txHead ] = pxNetworkBuffer;
		/* The descriptor is now owned by Micrel. */
		xMicrelDevice.tx_busy[ txHead ] = pdTRUE;

		/* Move the head pointer. */
		if( ++txHead == MICREL_TX_BUFFERS )
		{
			txHead = 0;
		}
		xMicrelDevice.us_tx_head = txHead;
		if( xEMACTaskHandle != NULL )
		{
			xTaskNotifyGive( xEMACTaskHandle );
		}

	#if( ipconfigZERO_COPY_TX_DRIVER != 1 )
		#warning Please ipconfigZERO_COPY_TX_DRIVER as 1
	#endif
		configASSERT( bReleaseAfterSend != pdFALSE );
		xResult = pdTRUE;
	}
	if( ( xResult == pdFALSE ) && ( bReleaseAfterSend  != pdFALSE ) )
	{
		vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
	}
	return xResult;
}
/*-----------------------------------------------------------*/

/* This Micrel has numbered it's PHY registers in a different way.
Translate the register index. */
static int ks8851_phy_reg( int reg )
{
	switch (reg) {
	case PHY_REG_00_BMCR:
		return REG_PHY_CNTL;	// P1MBCR;
	case PHY_REG_01_BMSR:
		return REG_PHY_STATUS;
	case PHY_REG_02_PHYSID1:
		return REG_PHY_ID_LOW;
	case PHY_REG_03_PHYSID2:
		return REG_PHY_ID_HIGH;
	case PHY_REG_04_ADVERTISE:
		return REG_PHY_AUTO_NEGOTIATION;
	case PHY_REG_05_LPA:
		return REG_PHY_REMOTE_CAPABILITY;
	}

	return 0x0;
}
/*-----------------------------------------------------------*/

static inline unsigned long ulReadMDIO( unsigned uAddress )
{
uint16_t usPHYStatus;
int ks8851_reg = ks8851_phy_reg( uAddress );

	if( ks8851_reg != 0 )
	{
		usPHYStatus = ksz8851_reg_read( ks8851_reg );
	}
	else
	{
		/* Other addresses not yet implemented. */
		usPHYStatus = 0;
	}
	return usPHYStatus;
}
/*-----------------------------------------------------------*/

static BaseType_t xGMACWaitLS( TickType_t xMaxTime )
{
TickType_t xStartTime = xTaskGetTickCount();
TickType_t xEndTime;
BaseType_t xReturn;
const TickType_t xShortTime = pdMS_TO_TICKS( 100UL );
const uint32_t ulHz_Per_MHz = 1000000UL;

	for( ;; )
	{
		xEndTime = xTaskGetTickCount();

		if( ( xEndTime - xStartTime ) > xMaxTime )
		{
			/* Wated more than xMaxTime, return. */
			xReturn = pdFALSE;
			break;
		}

		/* Check the link status again. */
		ulPHYLinkStatus = ulReadMDIO( PHY_REG_01_BMSR );

		if( ( ulPHYLinkStatus & BMSR_LINK_STATUS ) != 0 )
		{
			/* Link is up - return. */
			xReturn = pdTRUE;
			break;
		}

		/* Link is down - wait in the Blocked state for a short while (to allow
		other tasks to execute) before checking again. */
		vTaskDelay( xShortTime );
	}

	FreeRTOS_printf( ( "xGMACWaitLS: %ld freq %lu Mz\n",
		xReturn,
		sysclk_get_cpu_hz() / ulHz_Per_MHz ) );

	return xReturn;
}
/*-----------------------------------------------------------*/

static void vPioSetPinHigh(uint32_t ul_pin)
{
	Pio *p_pio = (Pio *)((uint32_t)PIOA + (PIO_DELTA * (ul_pin >> 5)));
	// Value to be driven on the I/O line: 1.
	p_pio->PIO_SODR = 1 << (ul_pin & 0x1F);
}

/**
 * \brief Handler for SPI interrupt.
 */
void SPI_Handler(void)
{
BaseType_t xDoWakeup = pdFALSE;
BaseType_t xKSZTaskWoken = pdFALSE;
uint32_t ulCurrentSPIStatus;
uint32_t ulEnabledSPIStatus;

	ulCurrentSPIStatus = spi_read_status( KSZ8851SNL_SPI );
	ulEnabledSPIStatus = spi_read_interrupt_mask( KSZ8851SNL_SPI );
	ulCurrentSPIStatus &= ulEnabledSPIStatus;
	spi_disable_interrupt( KSZ8851SNL_SPI, ulCurrentSPIStatus );


	switch( xMicrelDevice.ul_spi_pdc_status )
	{
		case SPI_PDC_RX_START:
		{
			if( ( ulCurrentSPIStatus & SPI_SR_OVRES ) != 0 )
			{
				pdc_disable_transfer(g_p_spi_pdc, PERIPH_PTCR_RXTDIS | PERIPH_PTCR_TXTDIS);
				xMicrelDevice.ul_spi_pdc_status = SPI_PDC_RX_ERROR;
				xDoWakeup = pdTRUE;
			}
			else
			{
				if( ( ulCurrentSPIStatus & SPI_SR_RXBUFF ) != 0 )
				{
					xMicrelDevice.ul_spi_pdc_status = SPI_PDC_RX_COMPLETE;
					xDoWakeup = pdTRUE;
				}
			}
		}
		break;

		case SPI_PDC_TX_START:
		{
			/* Middle of TX. */
			if( ( ulCurrentSPIStatus & SPI_SR_OVRES ) != 0 )
			{
				pdc_disable_transfer(g_p_spi_pdc, PERIPH_PTCR_RXTDIS | PERIPH_PTCR_TXTDIS);
				xMicrelDevice.ul_spi_pdc_status = SPI_PDC_TX_ERROR;
				xDoWakeup = pdTRUE;
			}
			else
			{
				if( ( ulCurrentSPIStatus & SPI_SR_ENDRX ) != 0 )
				{
					/* Enable RX complete interrupt. */
					spi_enable_interrupt( KSZ8851SNL_SPI, SPI_IER_RXBUFF );
				}
				/* End of TX. */
				if( ( ulCurrentSPIStatus & SPI_END_OF_TX ) != 0 )
				{
					xMicrelDevice.ul_spi_pdc_status = SPI_PDC_TX_COMPLETE;
					xDoWakeup = pdTRUE;
				}
			}
		}
		break;
	}	/* switch( xMicrelDevice.ul_spi_pdc_status ) */

	if( xDoWakeup != pdFALSE )
	{
		if( xEMACTaskHandle != NULL )
		{
			vTaskNotifyGiveFromISR( xEMACTaskHandle, ( BaseType_t * ) &xKSZTaskWoken );
		}
	}
	else
	{
	}
	portEND_SWITCHING_ISR( xKSZTaskWoken );
}
/*-----------------------------------------------------------*/

static void INTN_Handler(uint32_t id, uint32_t mask)
{
BaseType_t xKSZTaskWoken = pdFALSE;

	if( ( id == INTN_ID ) &&
		( mask == INTN_PIN_MSK ) )
	{
		/* Clear the PIO interrupt flags. */
		pio_get_interrupt_status( INTN_PIO );

		/* Set the INTN flag. */
		xMicrelDevice.ul_had_intn_interrupt++;
		if( xEMACTaskHandle != NULL )
		{
			vTaskNotifyGiveFromISR( xEMACTaskHandle, &( xKSZTaskWoken ) );
		}
	}
	portEND_SWITCHING_ISR( xKSZTaskWoken );
}
/*-----------------------------------------------------------*/

/**
 * \brief Populate the RX descriptor ring buffers with pbufs.
 *
 * \param p_ksz8851snl_dev Pointer to driver data structure.
 */
static void ksz8851snl_rx_populate_queue( void )
{
	uint32_t ul_index = 0;
	NetworkBufferDescriptor_t *pxNetworkBuffer;

	/* Set up the RX descriptors */
	for (ul_index = 0; ul_index < MICREL_RX_BUFFERS; ul_index++) {
		if( xMicrelDevice.rx_buffers[ ul_index ] == NULL )
		{
			/* Allocate a new NetworkBufferDescriptor_t with the maximum size. */
			pxNetworkBuffer = pxGetNetworkBufferWithDescriptor( ipconfigNETWORK_MTU + 36, 100 );
			if( pxNetworkBuffer == NULL )
			{
				FreeRTOS_printf( ( "ksz8851snl_rx_populate_queue: NetworkBufferDescriptor_t allocation failure\n" ) );
				configASSERT( 1 == 2 );
			}

			/* Make sure lwIP is well configured so one NetworkBufferDescriptor_t can contain the maximum packet size. */
			//LWIP_ASSERT("ksz8851snl_rx_populate_queue: NetworkBufferDescriptor_t size too small!", pbuf_clen(pxNetworkBuffer) <= 1);

			/* Save NetworkBufferDescriptor_t pointer to be sent to lwIP upper layer. */
			xMicrelDevice.rx_buffers[ ul_index ] = pxNetworkBuffer;
			/* Pass it to Micrel for reception. */
			xMicrelDevice.rx_ready[ ul_index ] = pdFALSE;
		}
	}
}

unsigned tx_space, wait_tx_space, tx_status, fhr_status;
unsigned rx_debug = 0;
/**
 * \brief Update Micrel state machine and perform required actions.
 *
 * \param netif the lwIP network interface structure for this ethernetif.
 */
static void ksz8851snl_update()
{
	uint16_t txmir = 0;

/* Check for free PDC. */
	switch( xMicrelDevice.ul_spi_pdc_status )
	{
	case SPI_PDC_TX_ERROR:
		{
		uint32_t ulValue;
	//		/* TX step11: end TX transfer. */
			gpio_set_pin_high( KSZ8851SNL_CSN_GPIO );

			vTaskDelay( 2 ); gpio_set_pin_low( KSZ8851SNL_CSN_GPIO );
			vTaskDelay( 1 ); gpio_set_pin_high( KSZ8851SNL_CSN_GPIO );
			vTaskDelay( 1 );

			/* Disable asynchronous transfer mode. */
			xMicrelDevice.ul_spi_pdc_status = SPI_PDC_IDLE;

			/* TX step12: disable TXQ write access. */
			ksz8851_reg_clrbits( REG_RXQ_CMD, RXQ_START );

			ulValue = ksz8851snl_reset_tx();

			xMicrelDevice.tx_space = ksz8851_reg_read( REG_TX_MEM_INFO ) & TX_MEM_AVAILABLE_MASK;

			FreeRTOS_printf( ("SPI_PDC_TX_ERROR %02X\n", ulValue ) );
		}
		break;

	case SPI_PDC_RX_ERROR:
		{
		uint32_t ulValue;
			/* TX step11: end TX transfer. */
			gpio_set_pin_high( KSZ8851SNL_CSN_GPIO );

			vTaskDelay( 2 ); gpio_set_pin_low( KSZ8851SNL_CSN_GPIO );
			vTaskDelay( 1 ); gpio_set_pin_high( KSZ8851SNL_CSN_GPIO );
			vTaskDelay( 1 );

			/* Disable asynchronous transfer mode. */
			xMicrelDevice.ul_spi_pdc_status = SPI_PDC_IDLE;

			/* TX step12: disable TXQ write access. */
			ksz8851_reg_clrbits( REG_RXQ_CMD, RXQ_START );

			//ulValue = ksz8851snl_reset_rx();
			ulValue = ksz8851snl_reinit();

			xGMACWaitLS( pdMS_TO_TICKS( 5000UL ) );

			FreeRTOS_printf( ("SPI_PDC_RX_ERROR %02X\n", ulValue ) );
		}
		break;
	}
	switch( xMicrelDevice.ul_spi_pdc_status )
	{
		case SPI_PDC_IDLE:
		{
		int txTail = xMicrelDevice.us_tx_tail;

			/*
			 * ========================== Handle RX ==========================
			 */
			if( ( xMicrelDevice.ul_had_intn_interrupt != 0 ) || ( xMicrelDevice.us_pending_frame > 0 ) )
			{
			int rxHead = xMicrelDevice.us_rx_head;
			NetworkBufferDescriptor_t *pxNetworkBuffer;
#warning try
				xMicrelDevice.ul_had_intn_interrupt = 0;

				if( xMicrelDevice.us_pending_frame == 0 )
				{
				uint16_t int_status;
					/* RX step1: read interrupt status for INT_RX flag. */
					int_status = ksz8851_reg_read( REG_INT_STATUS );


					/* RX step2: disable all interrupts. */
					ksz8851_reg_write( REG_INT_MASK, 0 );

					/* RX step3: clear INT_RX flag. */
					ksz8851_reg_setbits( REG_INT_STATUS, INT_RX );

					/* RX step4-5: check for received frames. */
					xMicrelDevice.us_pending_frame = ksz8851_reg_read(REG_RX_FRAME_CNT_THRES) >> 8;
					if( xMicrelDevice.us_pending_frame == 0 )
					{
						/* RX step24: enable INT_RX flag. */
						ksz8851_reg_write(REG_INT_MASK, INT_RX);
						return;
					}
				}
#warning try
				xMicrelDevice.ul_had_intn_interrupt = 0;

				/* Now xMicrelDevice.us_pending_frame != 0 */

				/* Don't break Micrel state machine, wait for a free descriptor first! */
				if( xMicrelDevice.rx_ready[ rxHead ] != pdFALSE )
				{
					FreeRTOS_printf( ( "ksz8851snl_update: out of free descriptor! [tail=%u head=%u]\n",
							xMicrelDevice.us_rx_tail, rxHead ) );
					return;
				}
				pxNetworkBuffer = xMicrelDevice.rx_buffers[ rxHead ];

				if( pxNetworkBuffer == NULL )
				{
					ksz8851snl_rx_populate_queue();
					FreeRTOS_printf( ( "ksz8851snl_update: no buffer set [head=%u]\n", rxHead ) );
					return;
				}

				/* RX step6: get RX packet status. */
				fhr_status = ksz8851_reg_read( REG_RX_FHR_STATUS );
				if( ( ( fhr_status & RX_VALID ) == 0 ) || ( ( fhr_status & RX_ERRORS ) != 0 ) )
				{
					ksz8851_reg_setbits(REG_RXQ_CMD, RXQ_CMD_FREE_PACKET);
					FreeRTOS_printf( ( "ksz8851snl_update: RX packet error!\n" ) );

					/* RX step4-5: check for received frames. */
					xMicrelDevice.us_pending_frame = ksz8851_reg_read(REG_RX_FRAME_CNT_THRES) >> 8;
					if( xMicrelDevice.us_pending_frame == 0 )
					{
						/* RX step24: enable INT_RX flag. */
						ksz8851_reg_write(REG_INT_MASK, INT_RX);
					}
					ulISREvents |= EMAC_IF_ERR_EVENT;
				}
				else
				{
				size_t xLength;
					/* RX step7: read frame length. */
					xLength = ksz8851_reg_read(REG_RX_FHR_BYTE_CNT) & RX_BYTE_CNT_MASK;

					/* RX step8: Drop packet if len is invalid or no descriptor available. */
					if( xLength == 0 )
					{
						ksz8851_reg_setbits( REG_RXQ_CMD, RXQ_CMD_FREE_PACKET );
						FreeRTOS_printf( ( "ksz8851snl_update: RX bad len!\n" ) );
						ulISREvents |= EMAC_IF_ERR_EVENT;
					}
					else
					{
					size_t xReadLength = xLength;

						xMicrelDevice.ul_total_rx++;
						/* RX step9: reset RX frame pointer. */
						ksz8851_reg_clrbits(REG_RX_ADDR_PTR, ADDR_PTR_MASK);

						/* RX step10: start RXQ read access. */
						ksz8851_reg_setbits(REG_RXQ_CMD, RXQ_START);
						/* RX step11-17: start asynchronous FIFO read operation. */
						xMicrelDevice.ul_spi_pdc_status = SPI_PDC_RX_START;
						gpio_set_pin_low( KSZ8851SNL_CSN_GPIO );
						if( ( xReadLength & ( sizeof( size_t ) - 1 ) ) != 0 )
						{
							xReadLength = ( xReadLength | ( sizeof( size_t ) - 1 ) ) + 1;
						}

						/* Pass the buffer minus 2 bytes, see ksz8851snl.c: RXQ_TWOBYTE_OFFSET. */
						ksz8851_fifo_read( pxNetworkBuffer->pucEthernetBuffer - 2, xReadLength );
						/* Remove CRC and update buffer length. */
						xLength -= 4;
						pxNetworkBuffer->xDataLength = xLength;
						/* Wait for SPI interrupt to set status 'SPI_PDC_RX_COMPLETE'. */
					}
				}
				break;
			} /* ul_had_intn_interrupt || us_pending_frame */
			/*
			 * ========================== Handle TX ==========================
			 */

			/* Fetch next packet to be sent. */
			if( ( xMicrelDevice.tx_busy[ txTail ] != pdFALSE ) &&
				( xMicrelDevice.us_pending_frame == 0 ) &&
				( xMicrelDevice.ul_had_intn_interrupt == 0 ) )
			{
			NetworkBufferDescriptor_t *pxNetworkBuffer = xMicrelDevice.tx_buffers[ txTail ];
			size_t xLength = pxNetworkBuffer->xDataLength;
			int iIndex = xLength;

				xLength = 4 * ( ( xLength + 3 ) / 4 );
				while( iIndex < ( int ) xLength )
				{
					pxNetworkBuffer->pucEthernetBuffer[ iIndex ] = '\0';
					iIndex++;
				}
				pxNetworkBuffer->xDataLength = xLength;

				/* TX step1: check if TXQ memory size is available for transmit. */
				txmir = ksz8851_reg_read( REG_TX_MEM_INFO );
				txmir = txmir & TX_MEM_AVAILABLE_MASK;

				if( txmir < ( xLength + 8 ) )
				{
					if( wait_tx_space == pdFALSE )
					{
						tx_status = ksz8851_reg_read( REG_TX_STATUS );
						fhr_status = ksz8851_reg_read( REG_RX_FHR_STATUS );
						wait_tx_space = pdTRUE;
					}
					//return;
					rx_debug = 1;
					tx_space = txmir;
				}
				else
				{
					tx_space = txmir;

					/* TX step2: disable all interrupts. */
					ksz8851_reg_write( REG_INT_MASK, 0 );

					xMicrelDevice.tx_space -= xLength;

					/* TX step3: enable TXQ write access. */
					ksz8851_reg_setbits( REG_RXQ_CMD, RXQ_START );
					/* TX step4-8: perform FIFO write operation. */
					xMicrelDevice.ul_spi_pdc_status = SPI_PDC_TX_START;
					xMicrelDevice.tx_cur_buffer = pxNetworkBuffer;
					/* Bring SPI SS low. */
					gpio_set_pin_low( KSZ8851SNL_CSN_GPIO );
					xMicrelDevice.ul_total_tx++;

					ksz8851_fifo_write( pxNetworkBuffer->pucEthernetBuffer, xLength, xLength );
				}
			}
		}
		break;	/* SPI_PDC_IDLE */

	case SPI_PDC_RX_COMPLETE:
		{
		int rxHead = xMicrelDevice.us_rx_head;
			/* RX step18-19: pad with dummy data to keep dword alignment. */
			/* Packet lengths will be rounded up to a multiple of "sizeof size_t". */
//			xLength = xMicrelDevice.rx_buffers[ rxHead ]->xDataLength & 3;
//			if( xLength != 0 )
//			{
//				ksz8851_fifo_dummy( 4 - xLength );
//			}

			/* RX step20: end RX transfer. */
			gpio_set_pin_high( KSZ8851SNL_CSN_GPIO );

			/* Disable asynchronous transfer mode. */
			xMicrelDevice.ul_spi_pdc_status = SPI_PDC_IDLE;

			/* RX step21: end RXQ read access. */
			ksz8851_reg_clrbits(REG_RXQ_CMD, RXQ_START);

			/* RX step22-23: update frame count to be read. */
			xMicrelDevice.us_pending_frame -= 1;

			/* RX step24: enable INT_RX flag if transfer complete. */
			if( xMicrelDevice.us_pending_frame == 0 )
			{
				ksz8851_reg_write(REG_INT_MASK, INT_RX);
			}

			/* Mark descriptor ready to be read. */
			xMicrelDevice.rx_ready[ rxHead ] = pdTRUE;
			if( ++rxHead == MICREL_RX_BUFFERS )
			{
				rxHead = 0;
			}
			xMicrelDevice.us_rx_head = rxHead;
			if( rx_debug != 0 )
			{
			uint32_t txmir;
				rx_debug = 0;
				txmir = ksz8851_reg_read( REG_TX_MEM_INFO );
				txmir = txmir & TX_MEM_AVAILABLE_MASK;
			}
			/* Tell prvEMACHandlerTask that RX packets are available. */
			ulISREvents |= EMAC_IF_RX_EVENT;
		}	/* case SPI_PDC_RX_COMPLETE */
		break;

	case SPI_PDC_TX_COMPLETE:
		{
		int txTail = xMicrelDevice.us_tx_tail;
		NetworkBufferDescriptor_t *pxNetworkBuffer = xMicrelDevice.tx_buffers[ txTail ];

		size_t xLength;
			/* TX step9-10: pad with dummy data to keep dword alignment. */
			/* Not necessary: length is already a multiple of 4. */
			xLength = pxNetworkBuffer->xDataLength & 3;
			if( xLength != 0 )
			{
//				ksz8851_fifo_dummy( 4 - xLength );
			}

//			/* TX step11: end TX transfer. */
			gpio_set_pin_high( KSZ8851SNL_CSN_GPIO );

			/* Disable asynchronous transfer mode. */
			xMicrelDevice.ul_spi_pdc_status = SPI_PDC_IDLE;

			/* TX step12: disable TXQ write access. */
			ksz8851_reg_clrbits( REG_RXQ_CMD, RXQ_START );

			xMicrelDevice.tx_space = ksz8851_reg_read( REG_TX_MEM_INFO ) & TX_MEM_AVAILABLE_MASK;

			/* TX step12.1: enqueue frame in TXQ. */
			ksz8851_reg_setbits( REG_TXQ_CMD, TXQ_ENQUEUE );

			/* RX step13: enable INT_RX flag. */
//			ksz8851_reg_write( REG_INT_MASK, INT_RX );
			/* Buffer sent, free the corresponding buffer and mark descriptor as owned by software. */
			vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );

			xMicrelDevice.tx_buffers[ txTail ] = NULL;
			xMicrelDevice.tx_busy[ txTail ] = pdFALSE;
			if( ++txTail == MICREL_TX_BUFFERS )
			{
				txTail = 0;
			}

			xMicrelDevice.us_tx_tail = txTail;
			/* Experiment. */
			//xMicrelDevice.ul_had_intn_interrupt = 1;
			if( xTransmitHandle != NULL )
			{
				xTaskNotifyGive( xTransmitHandle );
			}
#warning moved downward
			/* RX step13: enable INT_RX flag. */
			ksz8851_reg_write( REG_INT_MASK, INT_RX );
			/* Prevent the EMAC task from sleeping a single time. */
			ulISREvents |= EMAC_IF_TX_EVENT;
		}	/* case SPI_PDC_TX_COMPLETE */
		break;
	}	/* switch( xMicrelDevice.ul_spi_pdc_status ) */
}

/**
 * \brief Set up the RX descriptor ring buffers.
 *
 * This function sets up the descriptor list used for RX packets.
 *
 */
static void ksz8851snl_rx_init()
{
	uint32_t ul_index = 0;

	/* Init pointer index. */
	xMicrelDevice.us_rx_head = 0;
	xMicrelDevice.us_rx_tail = 0;

	/* Set up the RX descriptors. */
	for (ul_index = 0; ul_index < MICREL_RX_BUFFERS; ul_index++) {
		xMicrelDevice.rx_buffers[ul_index] = NULL;
		xMicrelDevice.rx_ready[ul_index] = pdFALSE;
	}

	/* Build RX buffer and descriptors. */
	ksz8851snl_rx_populate_queue();
}

/**
 * \brief Set up the TX descriptor ring buffers.
 *
 * This function sets up the descriptor list used for TX packets.
 *
 */
static void ksz8851snl_tx_init()
{
	uint32_t ul_index = 0;

	/* Init TX index pointer. */
	xMicrelDevice.us_tx_head = 0;
	xMicrelDevice.us_tx_tail = 0;

	/* Set up the TX descriptors */
	for( ul_index = 0; ul_index < MICREL_TX_BUFFERS; ul_index++ )
	{
		xMicrelDevice.tx_busy[ul_index] = pdFALSE;
	}
	xMicrelDevice.tx_space = 6144;
}

/**
 * \brief Initialize ksz8851snl ethernet controller.
 *
 * \note Called from ethernetif_init().
 *
 * \param netif the lwIP network interface structure for this ethernetif.
 */
static void ksz8851snl_low_level_init( void )
{
	ksz8851snl_rx_init();
	ksz8851snl_tx_init();

	/* Enable NVIC interrupts. */
	NVIC_SetPriority(SPI_IRQn, INT_PRIORITY_SPI);
	NVIC_EnableIRQ(SPI_IRQn);

	/* Initialize SPI link. */
	if( ksz8851snl_init() < 0 )
	{
		FreeRTOS_printf( ( "ksz8851snl_low_level_init: failed to initialize the Micrel driver!\n" ) );
		configASSERT(0 == 1);
	}
	memset( xMicrelDevice.pusHashTable, 255, sizeof( xMicrelDevice.pusHashTable ) );
	ksz8851_reg_write( REG_MAC_HASH_0, FreeRTOS_htons( xMicrelDevice.pusHashTable[ 0 ] ) );
	ksz8851_reg_write( REG_MAC_HASH_2, FreeRTOS_htons( xMicrelDevice.pusHashTable[ 1 ] ) );
	ksz8851_reg_write( REG_MAC_HASH_4, FreeRTOS_htons( xMicrelDevice.pusHashTable[ 2 ] ) );
	ksz8851_reg_write( REG_MAC_HASH_6, FreeRTOS_htons( xMicrelDevice.pusHashTable[ 3 ] ) );

	/* Initialize interrupt line INTN. */
	configure_intn( INTN_Handler );
}

/**
 * \brief Use pre-allocated pbuf as DMA source and return the incoming packet.
 *
 * \param netif the lwIP network interface structure for this ethernetif.
 *
 * \return a pbuf filled with the received packet (including MAC header).
 * 0 on memory error.
 */
static NetworkBufferDescriptor_t *ksz8851snl_low_level_input( void )
{
NetworkBufferDescriptor_t *pxNetworkBuffer = NULL;
int rxTail = xMicrelDevice.us_rx_tail;

	/* Check that descriptor is owned by software (ie packet received). */
	if( xMicrelDevice.rx_ready[ rxTail ] != pdFALSE )
	{

		/* Fetch pre-allocated buffer */
		pxNetworkBuffer = xMicrelDevice.rx_buffers[ rxTail ];

		/* Remove this pbuf from its descriptor. */
		xMicrelDevice.rx_buffers[ rxTail ] = NULL;

		/* Clears rx_ready and sets rx_buffers. */
		ksz8851snl_rx_populate_queue();

		if( ++rxTail == MICREL_RX_BUFFERS )
		{
			rxTail = 0;
		}
		xMicrelDevice.us_rx_tail = rxTail;
	}

	return pxNetworkBuffer;
}
/*-----------------------------------------------------------*/

static uint32_t prvEMACRxPoll( void )
{
NetworkBufferDescriptor_t *pxNetworkBuffer;
IPStackEvent_t xRxEvent = { eNetworkRxEvent, NULL };
uint32_t ulReturnValue = 0;

	for( ;; )
	{
	/* Only for logging. */
	int rxTail = xMicrelDevice.us_rx_tail;
	EthernetHeader_t *pxEthernetHeader;

	pxNetworkBuffer = ksz8851snl_low_level_input();
	
		if( pxNetworkBuffer == NULL )
		{
			break;
		}
		pxEthernetHeader = ( EthernetHeader_t * ) ( pxNetworkBuffer->pucEthernetBuffer );

		if( ( pxEthernetHeader->usFrameType != ipIPv4_FRAME_TYPE ) &&
			( pxEthernetHeader->usFrameType != ipARP_FRAME_TYPE	) )
		{
			FreeRTOS_printf( ( "Frame type %02X received\n", pxEthernetHeader->usFrameType ) );
		}
		ulReturnValue++;

		xRxEvent.pvData = ( void * )pxNetworkBuffer;
		/* Send the descriptor to the IP task for processing. */
		if( xSendEventStructToIPTask( &xRxEvent, 100UL ) != pdTRUE )
		{
			vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
			iptraceETHERNET_RX_EVENT_LOST();
			FreeRTOS_printf( ( "prvEMACRxPoll: Can not queue return packet!\n" ) );
		}
	}

	return ulReturnValue;
}
/*-----------------------------------------------------------*/

static void prvEMACHandlerTask( void *pvParameters )
{
TimeOut_t xPhyTime;
TickType_t xPhyRemTime;
TickType_t xLoggingTime;
UBaseType_t uxLastMinBufferCount = 0;
UBaseType_t uxCurrentCount;
BaseType_t xResult = 0;
uint32_t xStatus;
const TickType_t ulMaxBlockTime = pdMS_TO_TICKS( EMAC_MAX_BLOCK_TIME_MS );
#if( ipconfigCHECK_IP_QUEUE_SPACE != 0 )
	UBaseType_t uxLastMinQueueSpace = 0;
#endif

	/* Remove compiler warnings about unused parameters. */
	( void ) pvParameters;

	configASSERT( xEMACTaskHandle );

	vTaskSetTimeOutState( &xPhyTime );
	xPhyRemTime = pdMS_TO_TICKS( PHY_LS_LOW_CHECK_TIME_MS );
	xLoggingTime = xTaskGetTickCount();

	for( ;; )
	{
		uxCurrentCount = uxGetMinimumFreeNetworkBuffers();
		if( uxLastMinBufferCount != uxCurrentCount )
		{
			/* The logging produced below may be helpful
			while tuning +TCP: see how many buffers are in use. */
			uxLastMinBufferCount = uxCurrentCount;
			FreeRTOS_printf( ( "Network buffers: %lu lowest %lu\n",
				uxGetNumberOfFreeNetworkBuffers(), uxCurrentCount ) );
		}

		#if( ipconfigCHECK_IP_QUEUE_SPACE != 0 )
		{
			uxCurrentCount = uxGetMinimumIPQueueSpace();
			if( uxLastMinQueueSpace != uxCurrentCount )
			{
				/* The logging produced below may be helpful
				while tuning +TCP: see how many buffers are in use. */
				uxLastMinQueueSpace = uxCurrentCount;
				FreeRTOS_printf( ( "Queue space: lowest %lu\n", uxCurrentCount ) );
			}
		}
		#endif /* ipconfigCHECK_IP_QUEUE_SPACE */

		/* Run the state-machine of the ksz8851 driver. */
		ksz8851snl_update();

		if( ( ulISREvents & EMAC_IF_ALL_EVENT ) == 0 )
		{
			/* No events to process now, wait for the next. */
			ulTaskNotifyTake( pdTRUE, ulMaxBlockTime );
		}

		if( ( xTaskGetTickCount() - xLoggingTime ) > 10000 )
		{
			xLoggingTime += 10000;
			FreeRTOS_printf( ( "Now Tx/Rx %7d /%7d\n",
				xMicrelDevice.ul_total_tx, xMicrelDevice.ul_total_rx ) );
		}

		if( ( ulISREvents & EMAC_IF_RX_EVENT ) != 0 )
		{
			ulISREvents &= ~EMAC_IF_RX_EVENT;

			/* Wait for the EMAC interrupt to indicate that another packet has been
			received. */
			xResult = prvEMACRxPoll();
		}

		if( ( ulISREvents & EMAC_IF_TX_EVENT ) != 0 )
		{
			/* Future extension: code to release TX buffers if zero-copy is used. */
			ulISREvents &= ~EMAC_IF_TX_EVENT;
		}

		if( ( ulISREvents & EMAC_IF_ERR_EVENT ) != 0 )
		{
			/* Future extension: logging about errors that occurred. */
			ulISREvents &= ~EMAC_IF_ERR_EVENT;
		}

		if( xResult > 0 )
		{
			/* As long as packets are being received, assume that
			the Link Status is high. */
			ulPHYLinkStatus |= BMSR_LINK_STATUS;
			/* A packet was received. No need to check for the PHY status now,
			but set a timer to check it later on. */
			vTaskSetTimeOutState( &xPhyTime );
			xPhyRemTime = pdMS_TO_TICKS( PHY_LS_HIGH_CHECK_TIME_MS );
			xResult = 0;
		}
		else if( ( xTaskCheckForTimeOut( &xPhyTime, &xPhyRemTime ) != pdFALSE ) &&
			( xMicrelDevice.ul_spi_pdc_status == SPI_PDC_IDLE ) )
		{
			/* Check the link status again. */
			xStatus = ulReadMDIO( PHY_REG_01_BMSR );

			if( ( ulPHYLinkStatus & BMSR_LINK_STATUS ) != ( xStatus & BMSR_LINK_STATUS ) )
			{
				ulPHYLinkStatus = xStatus;
				FreeRTOS_printf( ( "prvEMACHandlerTask: PHY LS now %d\n", ( ulPHYLinkStatus & BMSR_LINK_STATUS ) != 0 ) );
			}

			vTaskSetTimeOutState( &xPhyTime );
			if( ( ulPHYLinkStatus & BMSR_LINK_STATUS ) != 0 )
			{
				xPhyRemTime = pdMS_TO_TICKS( PHY_LS_HIGH_CHECK_TIME_MS );
			}
			else
			{
				xPhyRemTime = pdMS_TO_TICKS( PHY_LS_LOW_CHECK_TIME_MS );
			}
		}
	}
}
/*-----------------------------------------------------------*/