#include "rtl8139.h"

#include "string.h"
#include "stdio.h"
#include "stdlib.h"

#define DEBUG

static rtl8139_vtable_t const rtl8139_vtable = {
	{
	rtl8139_activate,
	rtl8139_deactivate,
	rtl8139_deinit,
	rtl8139_print_name,
	rtl8139_print_info
	}
};

// registers
#define REG_MAC0 0x00
#define REG_RBSTART 0x30
#define REG_CMD 0x37
#define REG_IMR 0x3C
#define REG_ISR 0x3E
#define REG_TCR 0x40
#define REG_RCR 0x44

// commands for REG_CMD (command register)
#define CMD_RESET 0x10
#define CMD_RECEIVER_ENABLE 0x08
#define CMD_TRANSMITTER_ENABLE 0x04

// mask for reading the version in from the REG_TCR (transmit configuration register)
#define TCR_MODEL_VERSION_AM 0x7C000000
#define TCR_MODEL_VERSION_BM 0x00C00000

// vendor identifiers received from the REG_TCR (transmit configuration register)
#define	TCR_MODEL_VERSION_RTL8139 0x60000000
#define	TCR_MODEL_VERSION_RTL8139A 0x70000000
#define	TCR_MODEL_VERSION_RTL8139B 0x78000000
#define	TCR_MODEL_VERSION_RTL8130 0x78000000
#define	TCR_MODEL_VERSION_RTL8139AG 0x74000000
#define	TCR_MODEL_VERSION_RTL8139C 0x74000000
#define	TCR_MODEL_VERSION_RTL8100 0x78800000
#define	TCR_MODEL_VERSION_RTL8100B 0x74400000
#define	TCR_MODEL_VERSION_RTL8139CP 0x74800000
#define	TCR_MODEL_VERSION_RTL8101 0x74C00000

// values for REG_TCR (transmit configuration register)
#define TCR_IFG_STANDARD 0x03000000
#define TCR_MXDMA_2048 0x00000700

// values for REG_RCR (receive configuration register)
#define RCR_MXDMA_UNLIMITED 0x00000700
#define RCR_ACCEPT_BROADCAST 0x00000008
#define RCR_ACCEPT_PHYS_MATCH 0x00000002

// values for REG_IMR/REG_ISR (interrupt mask/status registers)
#define ISR_SYSTEM_ERROR 0x8000
#define ISR_TIMEOUT 0x4000
#define ISR_CABLE_LENGTH_CHANGED 0x2000
#define ISR_RECEIVE_FIFO_OVERFLOW 0x0040
#define ISR_PACKET_UNDERRUN_LINK_CHANGED 0x0020
#define ISR_RECEIVE_BUFFER_OVERFLOW 0x0010
#define ISR_TRANSMIT_ERROR 0x0008
#define ISR_TRANSMIT_OK 0x0004
#define ISR_RECEIVE_ERROR 0x0002
#define ISR_RECEIVE_OK 0x0001

#define ISR_ALL \
	ISR_CABLE_LENGTH_CHANGED | ISR_TIMEOUT | ISR_SYSTEM_ERROR | \
	ISR_RECEIVE_FIFO_OVERFLOW | ISR_PACKET_UNDERRUN_LINK_CHANGED | \
	ISR_RECEIVE_BUFFER_OVERFLOW | ISR_TRANSMIT_ERROR | ISR_TRANSMIT_OK | \
	ISR_RECEIVE_ERROR | ISR_RECEIVE_OK

// for now we follow the guide line on OSDEV on the size of the receive buffer
#define RECEIVE_BUFFER_SIZE 8192 + 16 
 
void rtl8139_init( rtl8139_t *rtl8139, pci_device_descriptor_t *descriptor, interrupt_t *interrupt, void *context )
{
	memset( rtl8139, 0, sizeof( rtl8139_t ) );

	network_init( (network_t *)rtl8139, interrupt, context );

	rtl8139->pci_descriptor = *descriptor;

	puts( "Initializing driver for Realtek 8139 network card.." );

	for( int i = 0; i < NOF_MAC_REGISTERS; i++ ) {
		port8_init( &rtl8139->MAC_port[i], descriptor->port_base + REG_MAC0 + i );
	}
	port8_init( &rtl8139->CMD_port, descriptor->port_base + REG_CMD );
	port32_init( &rtl8139->RBSTART_port, descriptor->port_base + REG_RBSTART );
	port16_init( &rtl8139->IMR_port, descriptor->port_base + REG_IMR );
	port16_init( &rtl8139->ISR_port, descriptor->port_base + REG_ISR );
	port32_init( &rtl8139->TCR_port, descriptor->port_base + REG_TCR );
	port32_init( &rtl8139->RCR_port, descriptor->port_base + REG_RCR );

	// software reset, the CR_RESET bit remains high till the
	// reset is finished
	port8_write( &rtl8139->CMD_port, CMD_RESET );
	while( ( port8_read( &rtl8139->CMD_port ) & CMD_RESET ) == CMD_RESET );

	// get MAC
	for( int i = 0; i < NOF_MAC_REGISTERS; i++ ) {
		rtl8139->base.mac_address.byte[i] = port8_read( &rtl8139->MAC_port[i] );
	}

	// enable receiver and transmitter early
	port8_write( &rtl8139->CMD_port, CMD_RECEIVER_ENABLE | CMD_TRANSMITTER_ENABLE );

	// get model
	rtl8139->model_id = port32_read( &rtl8139->TCR_port ) & ( TCR_MODEL_VERSION_AM | TCR_MODEL_VERSION_BM );
	switch( rtl8139->model_id ) {

		case TCR_MODEL_VERSION_RTL8139:
			rtl8139->model = "RTL8139";
			break;

		case TCR_MODEL_VERSION_RTL8139A:
			rtl8139->model = "RTL8139A";
			break;

		// case TCR_MODEL_VERSION_RTL8139B:
		case TCR_MODEL_VERSION_RTL8130:
			rtl8139->model = "RTL8130/RTL8130B";
			break;

		// case TCR_MODEL_VERSION_RTL8139AG:
		case TCR_MODEL_VERSION_RTL8139C:
			rtl8139->model = "RTL8139A-G/RTL8139C";
			break;

		case TCR_MODEL_VERSION_RTL8100:
			rtl8139->model = "RTL8100";
			break;

		case TCR_MODEL_VERSION_RTL8100B:
			rtl8139->model = "RTL8100B";
			break;

		case TCR_MODEL_VERSION_RTL8139CP:
			rtl8139->model = "RTL8139C+";
			break;

		case TCR_MODEL_VERSION_RTL8101:
			rtl8139->model = "RTL8101";
			break;

		default:
			rtl8139->model = NULL;
			break;
	}

	// initialize TCR/RCR (take Lowlevel suggestions: TCR = 0x03000700, RCR = 0x0000070a)
	port32_write( &rtl8139->TCR_port, TCR_IFG_STANDARD | TCR_MXDMA_2048 );
	port32_write( &rtl8139->RCR_port, RCR_MXDMA_UNLIMITED | RCR_ACCEPT_BROADCAST | RCR_ACCEPT_PHYS_MATCH );

	// allocate receive buffer and register it
	rtl8139->receive_buffer = (uint8_t *)malloc( RECEIVE_BUFFER_SIZE );
	port32_write( &rtl8139->RBSTART_port, (uint32_t)rtl8139->receive_buffer );

	// register interrupts we are interested in (we want all and
	// filter them in the interrupt handler), read ISR to clear
	// the current values (if there are bits set)
	port16_write( &rtl8139->IMR_port, ISR_ALL );
	(void)port16_read( &rtl8139->ISR_port );

	interrupt_handler_init( &rtl8139->interrupt_handler, IRQ_BASE + descriptor->interrupt, interrupt, rtl8139_handle_interrupt, rtl8139 );
	interrupts_register_interrupt_handler( rtl8139->interrupt_handler );
	
	rtl8139_print_info( rtl8139 );

	((driver_t *)rtl8139)->vtable = (driver_vtable_t *)&rtl8139_vtable;
}

void rtl8139_activate( void *obj )
{
	puts( "Activating driver for Realtek 8139 network card.." );

	rtl8139_t *rtl8139 = obj;
}

void rtl8139_deactivate( void *obj )
{
	puts( "Dectivating driver for Realtek 8139 network card.." );

	rtl8139_t *rtl8139 = obj;
}

void rtl8139_deinit( void *obj )
{
	rtl8139_t *rtl8139 = (rtl8139_t *)obj;
	
	free( rtl8139->receive_buffer );
}

uint32_t rtl8139_handle_interrupt( interrupt_handler_t *handler, uint32_t esp )
{
	rtl8139_t *rtl8139 = (rtl8139_t *)handler->driver;

#ifdef DEBUG
	printf( "RTL8139 INTERRUPT\n" );
#endif

	return esp;
}

void rtl8139_print_name( void *obj )
{
	puts( "Realtek 8139 network card driver" );
}

void rtl8139_print_info( void *obj )
{
	rtl8139_t *rtl8139 = (rtl8139_t *)obj;

	char buf[20];
	char buf2[30];
	snprintf( buf2, 30, "unknown submodel 0x%X", rtl8139->model_id );
	network_mac_to_string( rtl8139->base.mac_address, buf, 20 );
	printf( "rtl8139 NIC type %s\n  at I/O base 0x%X, interrupt 0x%X, MAC: %s\n",
		( rtl8139->model != NULL ) ? rtl8139->model : buf2,
		rtl8139->pci_descriptor.port_base, rtl8139->pci_descriptor.interrupt, buf );
}