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project:usb:code:joystick [2007/04/27 01:21] (current)
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 +====== Joystick ======
  
 +This is my near-complete code, I don't think I'll have any time to actually "​finish"​ it, so I'll outline it's shortcomings here:
 +  * A HID-Class Get_Report request has never sent non-zero data in my experiments,​ but this may be because Get_Report and Set_Report were being issued at the same time
 +  * ''​Send_Report()''​ does not appear to handle multi-transfers properly (i.e. when sending reports larger than the endpoint buffer), this may be due to some fudging of the data on my part as there was not enough RAM to do a proper test of this.
 +  * Similarly, multi-transfers for Set_Report requests have not been tested very thoroughly. The little testing done was encouraging and I'm quite confident about the code which handles it.
 +  * X/Y axis of joystick don't seem to be controlled properly. I am sure the error lies in the report descriptor as I had this working before I changed that, and have not altered the code that produces and sends random data.
 +
 +{{project:​usb:​code:​joystick.hex|Download compiled HEX firmware}}
 +
 +<code cpp>
 +#include <​16f877.h>​
 +#include <​STDLIB.H>​ //​ Gives us RAND()
 +
 +//​--------------------------------------------------------
 +// Setup PIC and CCS compiler
 +#fuses XT, PUT, NOWDT, NOPROTECT
 +#use delay(clock = 4000000)
 +#case
 +
 +// By using C6 and C7, we will make use of the 877's hardware USART abilities
 +#use rs232(baud = 19200, xmit = PIN_C4, rcv = PIN_C5, stream=DEBUG)
 +
 +#use fast_io(a)
 +#use standard_io(c)
 +#byte port_a = 5
 +set_tris_a(0xFF);​ //​ All input
 +
 +#use standard_io(b)
 +#byte port_d = 8
 +
 +//​--------------------------------------------------------
 +// Debug options
 +// 0 is most verbose, 1 less so etc
 +
 +// Comment out the following line to bulid without debugging
 +// NB: This creates a LOT of warnings during compilation:​
 +//     a "Code has no effect"​ for each DEBUGx statement
 +
 +#define __DEBUGGING_ENABLED
 +
 +#ifdef __DEBUGGING_ENABLED
 + #define DEBUG0 if(DEBUG_LEVEL <= 0)DEBUGGED=1;​ if(DEBUG_LEVEL <= 0)printf
 + #define DEBUG1 if(DEBUG_LEVEL <= 1)DEBUGGED=1;​ if(DEBUG_LEVEL <= 1)printf
 + #define DEBUG2 if(DEBUG_LEVEL <= 2)DEBUGGED=1;​ if(DEBUG_LEVEL <= 2)printf
 + #define DEBUG3 if(DEBUG_LEVEL <= 3)DEBUGGED=1;​ if(DEBUG_LEVEL <= 3)printf
 + #define DEBUG4 if(DEBUG_LEVEL <= 4)DEBUGGED=1;​ if(DEBUG_LEVEL <= 4)printf
 + #define DEBUG5 if(DEBUG_LEVEL <= 5)DEBUGGED=1;​ if(DEBUG_LEVEL <= 5)printf
 + #define DEBUG6 if(DEBUG_LEVEL <= 6)DEBUGGED=1;​ if(DEBUG_LEVEL <= 6)printf
 + #define DEBUG7 if(DEBUG_LEVEL <= 7)DEBUGGED=1;​ if(DEBUG_LEVEL <= 7)printf
 +#else
 + #define DEBUG0
 + #define DEBUG1
 + #define DEBUG2
 + #define DEBUG3
 + #define DEBUG4
 + #define DEBUG5
 + #define DEBUG6
 + #define DEBUG7
 +#endif
 +
 +//​--------------------------------------------------------
 +// Definitions
 +
 +// Yellow LED
 +#define LED_N PIN_B7
 +
 +// Constants
 +#define ON 1
 +#define OFF 0
 +
 +#define D12_DATA 0
 +#define D12_COMMAND 1
 +
 +// D12 pins
 +#define D12_A0 PIN_B6
 +#define D12_WR_N PIN_B2
 +#define D12_RD_N PIN_B1
 +#define D12_SUSPEND PIN_B4
 +#define D12_INT_N PIN_B0
 +
 +// D12 Constants
 +#define D12_CTRL_BUFFER_SIZE 16 //​ (Bytes) Control buffer
 +#define D12_MAIN_BUFFER_SIZE 64 //​ (Bytes) Endpoint 2
 +
 +// D12 Endpoint indexes (for bitwise OR'ing with base commands)
 +#define CTRL_OUT 0
 +#define CTRL_IN 1
 +#define ENDPT1_OUT 2
 +#define ENDPT1_IN 3
 +#define ENDPT2_OUT 4
 +#define ENDPT2_IN 5
 +
 +// D12 Commands
 +#define SET_ADDRESS 0xD0
 +#define SET_ENDPT_ENABLE 0xD8
 +#define SET_MODE 0xF3
 +#define SET_DMA 0xFB
 +#define READ_INT 0xF4
 +#define SELECT_ENDPT 0x00 // + endpoint index
 +#define READ_ENDPT_STATUS 0x40 // + endpoint index
 +#define READ_BUFFER 0xF0
 +#define WRITE_BUFFER 0xF0
 +#define SET_ENDPT_STATUS 0x40 // + endpoint index
 +#define ACK_SETUP 0xF1
 +#define CLEAR_BUFFER 0xF2
 +#define VALIDATE_BUFFER 0xFA
 +#define SEND_RESUME 0xF6
 +#define READ_FRAME_NUM 0xF5
 +
 +// D12 Interrupt byte 1
 +#define INT_CTRL_OUT 0x01 // bit 0
 +#define INT_CTRL_IN 0x02 // bit 1
 +#define INT_ENDPT1_OUT 0x04 // bit 2
 +#define INT_ENDPT1_IN 0x08 // bit 3
 +#define INT_ENDPT2_OUT 0x10 // bit 4
 +#define INT_ENDPT2_IN 0x20 // bit 5
 +#define INT_BUS_RESET 0x40 // bit 6
 +#define INT_SUSPEND_CHANGE 0x80 // bit 7
 +
 +// D12 Interrupt byte 2
 +#define DMA_EOT_INT 0x01 // bit 0
 +
 +// D12 Last transaction status
 +#define STAT_XFER_SUCCESS 0x01 //​ bit 0 (1=Success)
 +#define STAT_ERROR 0x1E //​ bits 1-4
 +#define STAT_SETUP 0x20 //​ bit 5 (1=Last packet has setup token)
 +#define STAT_DATA 0x40 //​ bit 6 (0/1 to indicate DATA0 / DATA1 tag of packet)
 +#define STAT_NOT_READ 0x80 //​ bit 7 (1=Previous status not read (i.e. missed))
 +
 +// USB bmRequestTypes
 +#define REQTYPE_XFER_DIRECTION 0x80 //​ 0=OUT (Host to device), 1=IN (Device to host)
 +#define REQTYPE_CMD_TYPE 0x60 //​ 0=Standard 1=Class 3=Vendor
 +#define REQTYPE_RECIPIENT 0x1F //​ 0=Device, 1=Interface,​ 2=Endpoint, 3=Other
 +
 +// USB Standard request types
 +#define GET_STATUS_REQ 0x00
 +#define CLEAR_FEATURE_REQ 0x01
 +#define SET_FEATURE_REQ 0x03
 +#define SET_ADDRESS_REQ 0x05
 +#define GET_DESCRIPTOR_REQ 0x06
 +#define SET_DESCRIPTOR_REQ 0x07
 +#define GET_CONFIGURATION_REQ 0x08
 +#define SET_CONFIGURATION_REQ 0x09
 +#define GET_INTERFACE_REQ 0x0A
 +#define SET_INTERFACE_REQ 0x0B
 +#define SYNCH_FRAME_REQ 0x0C
 +
 +// USB HID Class request types
 +#define GET_REPORT 0x01
 +#define GET_IDLE 0x02
 +#define GET_PROTOCOL 0x03
 +#define SET_REPORT 0x09
 +#define SET_IDLE 0x0A
 +#define SET_PROTOCOL 0x0B
 +
 +// STATE
 +#define STATE_DEFAULT 0x00
 +#define STATE_ADDRESSED 0x01
 +#define STATE_CONFIGURED 0x02
 +
 +//​--------------------------------------------------------
 +// Structures and Enumerations
 +struct REQUEST {
 + int8 bmRequestType;​
 + int8 bRequest;​
 + int16 wValue;​
 + int16 wIndex;​
 + int16 wLength;​ //​ Data Phase'​s data length
 +};
 +
 +struct REPORT {
 + int8 buttons;​
 + int8 x;
 + int8 y;
 +};
 +
 +//​--------------------------------------------------------
 +// Global Variable Declarations
 +short DEBUGGED;​ //​ Flags if a DEBUGx statement was executed
 +short CTRL_IN_BUSY;​ //​ Used to determine if D12 CTRL_IN interrupt is because the buffer was (successfully) sent
 +short CTRL_IN_SEND_REPORT;​ //​ Flags if we need to send a report
 +unsigned char DEBUG_LEVEL;​ //​ Set by DIP switches on power up, and determines how verbose debugging is, via DEBUGx statements
 +unsigned char LOAD_CIN_OFFSET;​ //​ Used when sending descriptors via CTRL_IN
 +unsigned int16 LOAD_CIN_LENGTH;​
 +unsigned char REPORT_OUT[2];​
 +unsigned char LOAD_COUT_OFFSET;​ //​ Used when receiving reports via CTRL_OUT.
 +unsigned int16 LOAD_COUT_LENGTH;​
 +unsigned char SEND_REPORT_OFFSET;​ //​ Used when sending reports (any endpoint, assumes never sending more than one at a time)
 +unsigned char SET_ADDRESS_PENDING;​ //​ Flags the next CTRL_IN handler to send a null packet and then change the D12 address
 +unsigned char CONFIGURATION;​ //​ Indicates the selected configuration
 +unsigned char STATE;​ //​ USB device state. One of {Default, Addressed, Configured}
 +unsigned char ADDRESS;​ //​ Current device address on USB bus (used in state checks for standard requests)
 +struct REPORT REPORT_IN;
 +
 +//​--------------------------------------------------------
 +// USB Descriptors
 +
 +// Constants are stored in ROM, and hence cannot be accessed via pointers.
 +// Instead of having to duplicate code for each descriptor, we instead
 +// store them in a large block and '​parse'​ this block when a descriptor
 +// is requested.
 +unsigned char const DESCRIPTORS[] = {
 +// Device
 + 0x12,​ //​BYTE bLength
 + 0x01,​ //​BYTE bDescriptorType
 + 0x10,​ //​WORD (Lo) bcdUSB version supported
 + 0x01,​ //​WORD (Hi) bcdUSB version supported
 + 0x00,​ //​BYTE bDeviceClass
 + 0x00,​ //​BYTE bDeviceSubClass
 + 0x00,​ //​BYTE bDeviceProtocol
 + D12_CTRL_BUFFER_SIZE,​ //​BYTE bMaxPacketSize (probably 16 bytes)
 + 0x25,​ //​WORD (Lo) idVendor (Lakeview Research (of USB Complete))
 + 0x09,​ //​WORD (Hi) idVendor (Lakeview Research (of USB Complete))
 + 0x34,​ //​WORD (Lo) idProduct (for compatability with HID Class app)
 + 0x12,​ //​WORD (Hi) idProduct (for compatability with HID Class app)
 + 0x88,​ //​WORD (Lo) bcdDevice
 + 0x02,​ //​WORD (Hi) bcdDevice
 + 0x01,​ //​BYTE iManufacturer
 + 0x02,​ //​BYTE iProduct
 + 0x03,​ //​BYTE iSerialNumber
 + 0x01 //BYTE bNumConfigurations
 +
 +// Configuration & associated subdescriptors
 + // Configuration
 + 0x09,​ //​BYTE bLength (Configuration descriptor)
 + 0x02,​ //​BYTE bDescriptorType //Assigned by USB
 + 0x22,​ //​WORD (Lo) wTotalLength
 + 0x00,​ //​WORD (Hi) wTotalLength
 + 0x01,​ //​BYTE bNumInterfaces
 + 0x01,​ //​BYTE bConfigurationValue
 + 0x00,​ //​BYTE iConfiguration
 + 0xa0,​ //​BYTE bmAttributes,​ Bus powered and remote wakeup
 + 0x32,​ //​BYTE MaxPower, 100mA
 +
 + // Interface
 + 0x09,​ //​BYTE bLength (Interface descriptor)
 + 0x04,​ //​BYTE bDescriptionType,​ assigned by USB
 + 0x00,​ //​BYTE bInterfaceNumber
 + 0x00,​ //​BYTE bAlternateSetting
 + 0x01,​ //​BYTE bNumEndpoints,​ uses 1 endpoints
 + 0x03,​ //​BYTE bInterfaceClass,​ HID Class - 0x03
 + 0x00,​ //​BYTE bInterfaceSubClass
 + 0x00,​ //​BYTE bInterfaceProtocol
 + 0x00 //BYTE iInterface
 +
 + // HID
 + 0x09,​ //​BYTE bLength (HID Descriptor)
 + 0x21,​ //​BYTE bDescriptorType,​ assigned by USB
 + 0x10,​ //​WORD (Lo) bcdHID
 + 0x01,​ //​WORD (Hi) bcdHID
 + 0x00,​ //​BYTE bCountryCode
 + 0x01,​ //​BYTE bNumDescriptors
 + 0x22,​ //​BYTE bReportDescriptorType
 + 0x3D,​ //​WORD (Lo) wItemLength
 + 0x00,​ //​WORD (Hi) wItemLength
 +
 + // Endpoint
 + 0x07,​ //​BYTE bLength (Endpoint Descriptor)
 + 0x05,​ //​BYTE bDescriptorType,​ assigned by USB
 + 0x82,​ //​BYTE bEndpointAddress,​ IN endpoint, endpoint 1
 + 0x03,​ //​BYTE bmAttributes,​ Interrupt endpoint
 + 0x10,​ //​WORD (Lo) wMaxPacketSize
 + 0x00,​ //​WORD (Hi) wMaxPacketSize
 + 0xFF,​ //​BYTE bInterval
 +
 +// Lang_ID (String0)
 + 0x04,​ //​ bLength
 + 0x03,​ //​ bDescriptorType = String Desc
 + 0x09,​ //​ wLangID (Lo) (Lang ID for English = 0x0409)
 + 0x04,​ //​ wLangID (Hi) (Lang ID for English = 0x0409)
 +
 +// String1
 + 28+2,​ //​ bLength
 + 0x03 //​ bDescriptorType = String Desc
 + // Noting that text is always unicode, hence the '​padding'​
 + '​R',​ 00, '​o',​ 00, '​b',​ 00, '​e',​ 00, '​r',​ 00,
 + '​t',​ 00, ' ', 00, '​M',​ 00, '​e',​ 00, '​e',​ 00,
 + '​r',​ 00, '​m',​ 00, '​a',​ 00, '​n',​ 00,
 +
 +// String2
 + 22+2, // bLength
 + 0x03, // bDescriptorType = String Desc
 + // Noting that text is always unicode, hence the '​padding'​
 + '​R',​ 00, '​o',​ 00, '​b',​ 00, '​\'',​ 00, '​s',​ 00,
 + ' ', 00, '​G',​ 00, '​i',​ 00, '​z',​ 00, '​m',​ 00,
 + '​o',​ 00,
 +
 +// String3
 + 28+2, // bLength
 + 0x03, // bDescriptorType = String Desc
 + // Noting that text is always unicode, hence the '​padding'​
 + '​L',​ 00, '​i',​ 00, '​m',​ 00, '​i',​ 00, '​t',​ 00,
 + '​e',​ 00, '​d',​ 00, '​E',​ 00, '​d',​ 00, '​i',​ 00,
 + '​t',​ 00, '​i',​ 00, '​o',​ 00, '​n',​ 00,
 +
 +// Report, NOTE that bLength and bDescriptorType are NOT part of the report descriptor,
 +// and have been addded so that Get_Descriptor() can parse this char array.
 +// !! Remember to update wItemLength (which is in Hex) in the HID Descriptor !!
 + 61+2, // bLength (NOT PART OF DESCRIPTOR!)
 + 0x22, // bDescriptorType (NOT PART OF DESCRIPTOR!)
 +
 +    // Report descriptor proper
 +    0x05, 0x01,                    // USAGE_PAGE (Generic Desktop)
 +    0x09, 0x04,                    // USAGE (Joystick)
 +    0xa1, 0x01,                    // COLLECTION (Application)
 +    0x09, 0x01,                    //   USAGE (Pointer)
 +    0xa1, 0x00,                    //   ​COLLECTION (Physical)
 +    0x05, 0x09,                    //     ​USAGE_PAGE (Button)
 +    0x19, 0x01,                    //     ​USAGE_MINIMUM (Button 1)
 +    0x29, 0x03,                    //     ​USAGE_MAXIMUM (Button 3)
 +    0x15, 0x00,                    //     ​LOGICAL_MINIMUM (0)
 +    0x25, 0x01,                    //     ​LOGICAL_MAXIMUM (1)
 +    0x95, 0x03,                    //     ​REPORT_COUNT (3)
 +    0x75, 0x01,                    //     ​REPORT_SIZE (1)
 +    0x81, 0x02,                    //     INPUT (Data,​Var,​Abs)
 +    0x95, 0x01,                    //     ​REPORT_COUNT (1)
 +    0x75, 0x05,                    //     ​REPORT_SIZE (5)
 +    0x81, 0x03,                    //     INPUT (Cnst,​Var,​Abs)
 +    0x05, 0x01,                    //     ​USAGE_PAGE (Generic Desktop)
 +    0x09, 0x30,                    //     USAGE (X)
 +    0x09, 0x31,                    //     USAGE (Y)
 +    0x15, 0x81,                    //     ​LOGICAL_MINIMUM (-127)
 +    0x25, 0x7f,                    //     ​LOGICAL_MAXIMUM (127)
 +    0x75, 0x08,                    //     ​REPORT_SIZE (8)
 +    0x95, 0x02,                    //     ​REPORT_COUNT (2)
 +    0x81, 0x06,                    //     INPUT (Data,​Var,​Rel)
 +    0x06, 0x00, 0xff,              //     ​USAGE_PAGE (Generic Desktop)
 +    0x09, 0x01,                    //     USAGE (Vendor Usage 1)
 +    0x75, 0x08,                    //     ​REPORT_SIZE (8)
 +    0x95, 0x02,                    //     ​REPORT_COUNT (2)
 +    0x91, 0x02,                    //     ​OUTPUT (Data,​Var,​Abs)
 +    0xc0,                          //   ​END_COLLECTION
 +    0xc0                           // END_COLLECTION
 +};
 +
 +//​--------------------------------------------------------
 +// Function prototypes
 +void Init_PIC();
 +void Init_D12();
 +void D12_Write(unsigned char, int);
 +void D12_Read(unsigned char, int);
 +void D12_Interrupt_Handler();​
 +#SEPARATE void Handle_Ctrl_Out_EP();​
 +#SEPARATE void Stall_Endpt(int8);​
 +void Standard_Request(struct REQUEST *pReq);
 +void Get_Descriptor(struct REQUEST *pReq);
 +void Send_Null_Packet(int8);​
 +void Set_Address(struct REQUEST *pReq);
 +void Set_Configuration(struct REQUEST *pReq);
 +void Class_Request(struct REQUEST *pReq);
 +#SEPARATE void Handle_Ctrl_In_EP();​
 +#SEPARATE void Transaction_Error(int8);​
 +#SEPARATE void Debug_Request(struct REQUEST *pReq);
 +short Send_Report(int8);​
 +
 +//​--------------------------------------------------------
 +// Entry point
 +void main(void){
 +
 + DEBUGGED = 0;
 + Init_PIC();​ //​ Put pins in known state, reset D12 etc
 +
 + REPORT_IN.x = 0;
 + REPORT_IN.y = 0;
 + REPORT_IN.buttons = 0;
 +
 + // No need to init the D12, as it will trigger a bus reset interrupt as soon
 + // as it is powered / connects to the USB bus (not too sure which though)
 +
 + if(input(D12_INT_N) == 0) D12_Interrupt_Handler();​
 +
 + // Random data, or GBA controlled?
 + if(port_a & 0x08){ // PIN_A3
 + while(TRUE){
 + REPORT_IN.x = rand();
 + REPORT_IN.y = rand();
 + REPORT_IN.buttons = rand();
 + }
 + } else {
 + #use rs232(baud = 9600, xmit = PIN_C6, rcv = PIN_C7)
 + DEBUG7("​GBA Controller enabled!"​);​
 + #use rs232(baud = 19200, xmit = PIN_C4, rcv = PIN_C5)
 +
 + enable_interrupts(INT_RDA);​ //​ Enable RecieveDataAvailable (hardware USART double buffer has data)
 + while(TRUE);​ //​ Wait for (USART / D12) interrupt
 + }
 +
 +}
 +
 +//​--------------------------------------------------------
 +// Used for passing commands or data to the PDIUSBD12
 +void D12_Write(unsigned char type, int data)
 +{
 + int8 t;
 + switch(type)
 + {
 + case D12_DATA:
 + case D12_COMMAND:​
 + set_tris_d(0x00);​ //​ Set bus to output mode
 + output_high(D12_RD_N);​ //​ Ensure we don't conflict with RD_N
 +
 + if(type == D12_COMMAND)
 + output_high(D12_A0);​
 + else
 + output_low(D12_A0);​
 +
 + port_d = data; // Setup bus
 + t = 64;
 + while(t--);​ //​ Settling time (in PIC cycles)
 + output_low(D12_WR_N);​ //​ strobe for at least 20ns
 + output_high(D12_WR_N);​
 +
 + if(type == D12_COMMAND)
 + output_low(D12_A0);​
 + break;
 + default:
 + DEBUG7("​Error in D12_Write(),​ unknown type: 0x%x!\r\n",​ type);
 + DEBUG7("​Expecting one of:\r\n\t 0x%x\r\n\t0x%x\r\n",​ D12_COMMAND,​ D12_DATA);
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Used for reading data from the PDIUSBD12
 +void D12_Read(unsigned char* buffer, int reads)
 +{
 + int i, t;
 +
 + set_tris_d(0xFF);​ //​ Set bus to intput mode
 + for(i = 0; i<reads; i++)
 + {
 + output_low(D12_RD_N);​
 + t = 64;
 + while(t--);​ //​ Settling time (in PIC cycles)
 + buffer[i] = port_d; // Latch in the bus
 + output_high(D12_RD_N);​
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// FIXME: Probably want to save some registers when handling
 +//        this interrupt, as it takes quite a long time.
 +#INT_EXT
 +void D12_Interrupt_Handler()
 +{
 + unsigned char buffer[2], endpt_int, other_int;
 +
 + // Loop in case another interrupt is triggered while we handle this one
 + while(! input(D12_INT_N)){
 + // Don't add newlines if we've not sent any data to the terminal
 + if(DEBUGGED == 1){DEBUG7("​\r\n"​);​} //​ DEBUG7 is a two-statement macro, so it need braces
 + DEBUGGED = 0;
 +
 + D12_Write(D12_COMMAND,​ READ_INT);
 + D12_Read(buffer,​ 2);
 + endpt_int = buffer[0];
 + other_int = buffer[1];
 +
 + DEBUG0("​IR=%x,​%x ", endpt_int, other_int);
 +
 + if (endpt_int & INT_BUS_RESET) {
 + DEBUG7("​BR ");
 + // D12 Firmware programming guide recommends using a flag for this... ahh well
 + Init_D12();​ //​ Reset D12 settings and many global variables (not a chip reset)
 + } else
 + if (endpt_int & INT_SUSPEND_CHANGE) {
 + DEBUG1("​SC ");
 + } else
 + if(endpt_int & INT_CTRL_OUT) {
 + // Control Out Endpoint interrupt
 + DEBUG3("​CO ");
 + Handle_Ctrl_Out_EP();​
 + } else
 + if (endpt_int & INT_CTRL_IN) {
 + DEBUG2("​CI ");
 + Handle_Ctrl_In_EP();​
 + } else
 + if (endpt_int & INT_ENDPT1_OUT){
 + DEBUG3("​1O ");
 + }
 + if (endpt_int & INT_ENDPT1_IN) {
 + DEBUG3("​1I ");
 + } else
 + if(endpt_int & INT_ENDPT2_OUT) {
 + DEBUG3("​2O ");
 + } else
 + if (endpt_int & INT_ENDPT2_IN) {
 + DEBUG0("​2I ");
 + Send_Report(ENDPT2_IN);​
 + }
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Setups the hardware at its most basic level
 +void Init_PIC(){
 + output_low(LED_N);​ //​ Turn on the yellow LED
 +
 + set_tris_b(0x01);​ //​PIN_B1 (D12's INT) is input, the rest are output.
 + set_tris_d(0x00);​ //​All output
 + port_d = 0xFF;​ //​Set bus high, useful for checking the ribbon has not come loose
 +
 + output_high(D12_RD_N);​
 + output_high(D12_WR_N);​
 +
 + output_low(D12_A0);​ //​ Indicates bus is for data
 + output_low(D12_SUSPEND);​ //​ Prevent D12 from going into suspend
 +
 + disable_interrupts(GLOBAL);​ //​ Stop interrupts from interrupting us while we setup ;)
 +
 + ext_int_edge(H_TO_L);​ //​ Set up when to trigger
 + enable_interrupts(INT_EXT);​ //​ Enable external interrupts (connected to the D12's INT_N)
 + clear_interrupt(INT_EXT);​ //​ Remove pending interrupts
 + enable_interrupts(GLOBAL);​ //​ Enable all interrupts
 +
 + DEBUG_LEVEL = port_a & 0x07;// Read DIP switches (3 lower digits only)
 + DEBUG7("​\r\n\r\n%d ", DEBUG_LEVEL);​
 +}
 +
 +//​--------------------------------------------------------
 +// Takes the D12 out of reset and connects it to the USB bus
 +void Init_D12(){
 + STATE = STATE_DEFAULT;​ //​ Revert to default USB state
 + CONFIGURATION = 0; // Unconfigured
 + ADDRESS = 0; // Revert to default address
 + SET_ADDRESS_PENDING = 0; // Is not pending
 + LOAD_CIN_OFFSET = 0; // Start at beginning on next request
 + LOAD_CIN_LENGTH = 0; // Explicity state there is nothing to send
 + CTRL_IN_BUSY = 0; // It isn't
 + CTRL_IN_SEND_REPORT = 0; // Shouldn'​t be sending anything
 + SEND_REPORT_OFFSET = 0; // Ensure we start sending from the beginning
 +
 + D12_Write(D12_COMMAND,​ SET_ADDRESS);​
 + D12_Write(D12_DATA,​ 0x00 | 0x80);
 +
 + D12_Write(D12_COMMAND,​ SET_ENDPT_ENABLE);​
 + D12_Write(D12_DATA,​ 0x01);
 +
 + D12_Write(D12_COMMAND,​ SET_MODE);
 + D12_Write(D12_DATA,​ 0x1E); // Non-ISO, Softconnect,​ Interrupt for all, Clock running, no Lazyclock
 + D12_Write(D12_DATA,​ 0x0B); // Clock 4MHz, Set-to-one isn't, no SOF interrupts
 +}
 +
 +//​--------------------------------------------------------
 +// Check for a SETUP token, and act upon it
 +#SEPARATE
 +void Handle_Ctrl_Out_EP() {
 +
 + unsigned char buffer[2];
 + unsigned char data[D12_CTRL_BUFFER_SIZE];​
 + struct REQUEST *pReq; // Will be pointed to to data[] when appropriate
 + int i;
 +
 + D12_Write(D12_COMMAND,​ READ_ENDPT_STATUS + CTRL_OUT);​ //​ Clear interrupt
 + D12_Read(buffer,​ 1);
 + DEBUG3("​LT=%x ", buffer[0]);
 +
 + if(TRUE/​*buffer[0] & STAT_XFER_SUCCESS*/​){ //​ HID-Class "​Set_Report"​ never flags '​XFER_SUCCESS'​ :-\
 + if(buffer[0] & STAT_SETUP){ //​ Setup token
 +
 + D12_Write(D12_COMMAND,​ SELECT_ENDPT + CTRL_OUT);
 + D12_Read(data,​ 1);
 + DEBUG2("​SE=%x ", data[0]);
 +
 + D12_Write(D12_COMMAND,​ READ_BUFFER);​
 + D12_Read(data,​ D12_CTRL_BUFFER_SIZE);​
 + DEBUG2("​DL=%x ", data[1]);​ //​ Note that [0] is reserved, so [1] contains the data length
 +
 + // Acknowledge that we like this (NB CTRL_OUT is already selected)
 + D12_Write(D12_COMMAND,​ ACK_SETUP);
 + D12_Write(D12_COMMAND,​ CLEAR_BUFFER);​
 +
 + // Prevent previous data from being sent (need to ack_setup to re-enable clear buffer)
 + D12_Write(D12_COMMAND,​ SELECT_ENDPT + CTRL_IN);
 + D12_Write(D12_COMMAND,​ ACK_SETUP);
 + D12_Write(D12_COMMAND,​ CLEAR_BUFFER);​
 +
 + // Cancel any current control endpoint transactions
 + SEND_REPORT_OFFSET = 0;
 + LOAD_COUT_LENGTH = 0;
 + LOAD_CIN_LENGTH = 0;
 + CTRL_IN_SEND_REPORT = FALSE;
 +
 +
 + if(data[1] == 0x08){ // Valid setup token is 8 bytes
 + for(i=2;​ i<10; i++){
 + DEBUG0("​%x ", data[i]);
 + }
 + pReq = (struct REQUEST *) &​data[2];​ //​ [0] is reserved, [1] is data length, so [2] is actual data
 +
 + // Output some debugging info
 + if(DEBUG_LEVEL <= 1)Debug_Request(pReq);​
 +
 + switch((pReq->​bmRequestType & REQTYPE_CMD_TYPE) >> 5){
 + // Standard request
 + case 0x00:
 + DEBUG4("​SREQ ");
 + Standard_Request(pReq);​
 + break;
 +
 + // Class request
 + case 0x01:
 + DEBUG4("​CREQ ");
 + Class_Request(pReq);​
 + break;
 +
 + // Endpoint request
 + case 0x02:
 + DEBUG4("​EREQ ");
 + break;
 +
 + // Unsupported
 + default:​
 + DEBUG7("​\x07"​);​ //​ Bell character (^G)
 + DEBUG7("?​REQ=%x ", (pReq->​bmRequestType & REQTYPE_CMD_TYPE) >> 5);
 + // Stall this endpoint (indicating we cannot handle the request)
 + Stall_Endpt(CTRL_OUT);​
 + Debug_Request(pReq);​
 + break;
 + }
 + } else {
 + // Setup token is an invalid length
 + Stall_Endpt(CTRL_OUT);​
 + Debug_Request(pReq);​
 + }
 + } else
 + if(LOAD_COUT_LENGTH - LOAD_COUT_OFFSET){ //​ Are we expecting data?
 +
 + // Smaller of "how much we're expecting"​ and "how much the buffer can hold".
 + buffer[0] = ((LOAD_COUT_LENGTH - LOAD_COUT_OFFSET) > D12_CTRL_BUFFER_SIZE) ? D12_CTRL_BUFFER_SIZE : (LOAD_COUT_LENGTH - LOAD_COUT_OFFSET);​
 +
 + D12_Write(D12_COMMAND,​ SELECT_ENDPT + CTRL_OUT);
 + D12_Write(D12_COMMAND,​ READ_BUFFER);​
 + D12_Read(data,​ buffer[0]+2);​ //​ Get reserved byte and D12 buffer length as well
 +
 + DEBUG4("​EDl=%x ", buffer[0]);​ //​ Expected Data length
 + DEBUG4("​RDl=%x ", data[1]);​ //​ Received data length
 +
 + buffer[0] += 2; // Avoid calculating "​buffer[0]+2"​ each iter (we skip the reserved byte and D12 buffer length)
 + for(i=2; i<​buffer[0];​ i++){
 + REPORT_OUT[LOAD_COUT_OFFSET] = data[i];
 + LOAD_COUT_OFFSET++;​
 + }
 + D12_Write(D12_COMMAND,​ CLEAR_BUFFER);​
 +
 + // Print recieved data to GBA if we're done
 + if(LOAD_COUT_LENGTH - LOAD_COUT_OFFSET == 0){
 + #use rs232(baud = 9600, xmit = PIN_C6, rcv = PIN_C7) // Hardware USART (GBA)
 + printf("​["​);​
 + for(i=0;​ i<​LOAD_COUT_LENGTH;​ i++){
 + printf("​%x ", REPORT_OUT[i]);​
 + }
 + printf("​]"​);​
 + #use rs232(baud = 19200, xmit = PIN_C4, rcv = PIN_C5) // Software USART (Debug)
 + }
 + } else {
 + // Not a setup token and we're not expecting data
 + DEBUG7("​!Setup ");
 + D12_Write(D12_COMMAND,​ SELECT_ENDPT + CTRL_OUT);
 +
 + D12_Write(D12_COMMAND,​ READ_BUFFER);​
 + D12_Read(data,​ D12_CTRL_BUFFER_SIZE + 2); // Get preceeding reserved byte and D12 buffer length as well
 +
 + if(data[1] == 0){
 + DEBUG2("​N "); // Null
 + } else {
 + data[1] = (data[1] < D12_CTRL_BUFFER_SIZE) ? data[1] : D12_CTRL_BUFFER_SIZE;​
 +
 + data[1] += 2; // Avoid calculating "​data[1]+2"​ each iter (we skip the reserved byte and D12 buffer length)
 + for(i=2;​ i<​data[1];​ i++){
 + DEBUG7("​%x ", data[i]);
 + }
 + }
 + }
 + } else
 + if (buffer[0] & STAT_ERROR) //​ Last transaction wasn't successful
 + {
 + Transaction_Error(buffer[0] & STAT_ERROR);​
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Stalls an enpoint, so the D12 will return STALL to the host,
 +// which usually indicates we don't understand / support the host's
 +// request
 +#SEPARATE
 +void Stall_Endpt(int8 ENDPT)
 +{
 + DEBUG7("​S_"​);​
 + switch(ENDPT){
 + case 0: DEBUG7("​CO "); break;
 + case 1: DEBUG7("​CI "); break;
 + case 2: DEBUG7("​EO "); break;
 + case 3: DEBUG7("​EI "); break;
 + case 4: DEBUG7("​MO "); break;
 + case 5: DEBUG7("​MI "); break;
 + default: DEBUG7("?​(%x) ", ENDPT); break;
 + }
 + D12_Write(D12_COMMAND,​ SET_ENDPT_STATUS + ENDPT);
 + D12_Write(D12_DATA,​ 0x01);
 +}
 +
 +//​--------------------------------------------------------
 +// Handle standard USB requests, such as those encountered in
 +// SETUP tokens
 +void Standard_Request(struct REQUEST *pReq) {
 + short RequestOK = TRUE;
 +
 + switch(pReq->​bRequest){
 + case GET_STATUS_REQ:​
 + DEBUG4("​Get_Staus ");
 + if(STATE == STATE_CONFIGURED || (STATE == STATE_ADDRESSED && ADDRESS == 0)){
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case CLEAR_FEATURE_REQ:​
 + DEBUG4("​Clear_Feature ");
 + if(STATE == STATE_CONFIGURED || (STATE == STATE_ADDRESSED && ADDRESS == 0)){
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case SET_FEATURE_REQ:​
 + DEBUG4("​Set_feature ");
 + if(STATE == STATE_CONFIGURED || (STATE == STATE_ADDRESSED && ADDRESS == 0)){
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case SET_ADDRESS_REQ:​
 + DEBUG4("​Set_Address ");
 + if(STATE == STATE_DEFAULT || STATE == STATE_ADDRESSED){
 + Set_Address(pReq);​
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case GET_DESCRIPTOR_REQ:​
 + DEBUG4("​Get_Descriptor ");
 + if(STATE == STATE_DEFAULT || STATE == STATE_ADDRESSED || STATE == STATE_CONFIGURED){
 + Get_Descriptor(pReq);​
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case SET_DESCRIPTOR_REQ:​
 + DEBUG4("​Set_Descriptor ");
 + if(STATE == STATE_ADDRESSED || STATE == STATE_CONFIGURED){
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case GET_CONFIGURATION_REQ:​
 + DEBUG4("​Get_Configuration ");
 + if(STATE == STATE_ADDRESSED || STATE == STATE_CONFIGURED){ //​ Returns 0 if in addressed state
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case SET_CONFIGURATION_REQ:​
 + DEBUG4("​Set_Configuration ");
 + if(STATE == STATE_ADDRESSED || STATE == STATE_CONFIGURED){
 + Set_Configuration(pReq);​
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case GET_INTERFACE_REQ:​
 + DEBUG4("​Get_Interface ");
 + if(STATE == STATE_CONFIGURED){
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case SET_INTERFACE_REQ:​
 + DEBUG4("​Set_Interface ");
 + if(STATE == STATE_CONFIGURED){
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + case SYNCH_FRAME_REQ:​
 + DEBUG4("​Synch_Frame ");
 + if(STATE == STATE_CONFIGURED){
 + } else {
 + RequestOK = FALSE;
 + }
 + break;
 +
 + default:
 + RequestOK = FALSE;
 + DEBUG7("​\x07"​);​ //​ Bell character (^G)
 + DEBUG7("?​SREQ=%x ", pReq->​bRequest);​
 + break;
 + }
 +
 + if(RequestOK == FALSE){
 + DEBUG7("​StateIncompatable(%x,​%x) ", STATE, ADDRESS );
 + Stall_Endpt(CTRL_OUT);​
 + Debug_Request(pReq);​
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Service the host's request for a descriptor.
 +// Descriptos are stored end-to-end in a large block of ROM
 +// as the constant '​DESCRIPTORS'​.
 +// This block of ROM is searched/​parsed to see if it contains
 +// the requested descriptor.
 +void Get_Descriptor(struct REQUEST *pReq){
 +
 + unsigned int16 ReqDataLen, size;
 + unsigned char i, type, stringCount;​
 + ReqDataLen = pReq->​wLength;​
 + LOAD_CIN_LENGTH = 0; // Ensure we don't send unrelated data
 +
 + DEBUG0("​GD(%x) ", pReq->​wValue >> 8);
 + i = 0;
 + stringCount = 0;
 + while(i < sizeof(DESCRIPTORS)-1){
 + // Read details from current descriptor
 + size = (unsigned int16) DESCRIPTORS[i];​
 + type = DESCRIPTORS[i+1];​
 + DEBUG0("​i=%x(%x,​ %x) ", i, size, type);
 +
 + if(type == (pReq->​wValue >> 8)){ // High byte contains type
 +
 + // Take care of exceptions
 + switch(type){
 +
 + // Configuration descriptors are expected to be sent with all their subordinate
 + // descriptors.
 +
 + case 0x02: // Configuration descriptor
 + size =  (unsigned int16) DESCRIPTORS[i+2];​ //​ wTotalLength low-byte
 + size |= (unsigned int16) DESCRIPTORS[i+3] << 8; // wTotalLength high-byte
 + DEBUG0("​*CD(%x) ", size);
 + break;
 +
 + // There can be multiple string descriptors,​ addressed by index.
 +
 + case 0x03: // String descriptor
 + // Is there a need to try the next string?
 + if( (pReq->​wValue & 0x00FF) != stringCount){ //​ Low byte contains index for strings
 + stringCount++;​ //​ Note that we've checked a string
 + i = i + size; // Jump to next descriptor in loop
 + continue;​ //​ Restart while() loop
 + }
 + break;
 +
 +
 + // Some descriptors do NOT contain bLength and bType bytes, these have been added
 + // by the author to facilitate this parsing approach. Hence we reduce the size by 2
 + // bytes and increase the LOAD_CIN_OFFSET by 2 bytes in such cases.
 + // The artificial bLength value denotes the number of bytes until the next descriptor,
 + // to ensure this code can 'step into' the next descriptor.
 +
 + case 0x22: // Report descriptor
 + i = i + 2;
 + size = size - 2;
 + DEBUG0("​*RD(%x) ", size);
 + break;
 + }
 +
 + // Don't transmit more than we need to
 + if( ReqDataLen > size) ReqDataLen = size;
 +
 + // Setup globals for the Ctrl_IN interrupt handler
 + LOAD_CIN_OFFSET = i; // Start of descriptor
 + LOAD_CIN_LENGTH = ReqDataLen;
 +
 + DEBUG0("​Lo=%x Ll=%x ", LOAD_CIN_OFFSET,​ LOAD_CIN_LENGTH);​
 +
 + break; // Quit while() loop
 + } else {
 + // Types didn't match, try the next descriptor
 + i = i + size;
 + }
 + }
 +
 + if(LOAD_CIN_LENGTH == 0){ // We didn't find a match
 + DEBUG7("​\x07"​);​ //​ Bell character (^G)
 + DEBUG7("?​DR=%x ",​(pReq->​wValue >> 8));
 + // Not sure which endpoint would need to be stalled..
 + // presumably both as it's a bidirection endpoint of
 + // sorts
 + Stall_Endpt(CTRL_OUT);​
 + Stall_Endpt(CTRL_IN);​
 + Debug_Request(pReq);​
 + } else {
 + Handle_Ctrl_In_EP();​ //​ Kick-start descriptor sending
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// When an error code is encountered from a 'Read Last Transaction Command'​
 +// this function is called to clean up the mess
 +
 +#SEPARATE void Transaction_Error(int8 error){
 + DEBUG7("​!LT=%x ", error);
 + switch (error)
 + {
 + case 0x02 : //0001 PID Encoding Error
 + case 0x04 : //0010 PID Unknown
 + case 0x06 : //0011 Unexpected packet
 + case 0x08 : //0100 Token CRC Error
 + case 0x0A : //0101 Data CRC Error
 + case 0x0C : //0110 Time out Error
 + case 0x0E : //0111 Never happens
 + case 0x10 : //1000 Unexpected End of Packet
 + case 0x12 : //1001 Sent or received NAK
 + case 0x14 : //1010 Sent Stall, token received Endpt Stalled
 + case 0x16 : //1011 Overflow Error
 + case 0x1A : //1101 BitStuff Error
 + case 0x1E : //1111 Wrong DATA PID
 + break;
 + default :
 + DEBUG7("​\x07"​);​ //​ Bell character (^G)
 + DEBUG7("?​LT=%x ", error);
 + break;
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Output debugging info about a USB request
 +
 +#SEPARATE void Debug_Request(struct REQUEST *pReq){
 +#ifdef __DEBUGGING_ENABLED
 + printf("​DIR="​);​
 + if(pReq->​bmRequestType & REQTYPE_XFER_DIRECTION){
 + printf("​I ");
 + } else {
 + printf("​O ");
 + }
 +
 + printf("​TO="​);​
 + switch(pReq->​bmRequestType & REQTYPE_RECIPIENT){
 +
 + case 0x00: printf("​D "); break; // Device
 + case 0x01: printf("​I "); break; // Interface
 + case 0x02: printf("​E "); break; // Endpoint
 + case 0x03: printf("?​ "); break; // Other
 +
 + // Unsupported
 + default:
 + DEBUG7("​\x07"​);​ //​ Bell character (^G)
 + // Stall this endpoint (indicating we cannot handle the request)
 + Stall_Endpt(CTRL_OUT);​
 + break;
 + }
 +
 + printf("​wV=%Lx ", pReq->​wValue);​
 + printf("​wI=%Lx ", pReq->​wIndex);​
 + printf("​wL=%Lx ", pReq->​wLength);​
 +#endif
 +}
 +
 +//​--------------------------------------------------------
 +// Responds to the Set_Address request of the host, and then
 +// sets the D12 address (NB: The D12's address is actually
 +// changed AFTER the null packet phase )
 +void Set_Address(struct REQUEST *pReq){
 +
 + // The D12 buffers the Set_Address command and executes it upon recieving an ACK
 + // in reply to the null packet we'll send in a moment.
 + D12_Write(D12_COMMAND,​ SET_ADDRESS);​
 + D12_Write(D12_DATA,​ (pReq->​wValue | 0x80));
 +
 + ADDRESS = (pReq->​wValue | 0x80); // Update our current address
 + STATE = STATE_ADDRESSED;​
 +
 + // Acknowledge token by replying with a null data packet
 + Send_Null_Packet(CTRL_IN);​
 +
 + CTRL_IN_BUSY = TRUE; // Unless something else is pending, the next CTRL_IN interrupt just means the data was sent
 + DEBUG3("​AS ");
 +
 +}
 +
 +//​--------------------------------------------------------
 +// Send a zero-length packet to the selected endpoint
 +// Useful for empty data stages in setup transactions,​ as well
 +// as signalling the end of a stream when the last packet was
 +// full (i.e. don't let the host assume there is no more data,
 +// tell it!)
 +void Send_Null_Packet(int8 ENDPT) {
 + D12_Write(D12_COMMAND,​ SELECT_ENDPT + ENDPT);
 + D12_Write(D12_COMMAND,​ WRITE_BUFFER);​
 + D12_Write(D12_DATA,​ 0); // First packet is reserved
 + D12_Write(D12_DATA,​ 0); // Data length (zero-length packet)
 + D12_Write(D12_COMMAND,​ VALIDATE_BUFFER);​
 +
 + CTRL_IN_BUSY = TRUE;
 +
 + DEBUG3("​Z ");
 +}
 +
 +//​--------------------------------------------------------
 +// Responds to Set_Confugration request of the host, checks the
 +// requested configuration is supported and responds appropriately with
 +// an ACK or a STALL, and updates the global state variable.
 +void Set_Configuration(struct REQUEST *pReq){
 + short RequestOK = 1;
 +
 + switch(pReq->​wValue & 0x00FF){ // Only interested in lower byte
 + case 0:
 + // Revert to unconfigured state
 + STATE = STATE_ADDRESSED;​
 + CONFIGURATION = 0;
 + break;
 +
 + case 1:
 + STATE = STATE_CONFIGURED;​
 + CONFIGURATION = 1;
 + Send_Report(ENDPT2_IN);​ //​ Kick-start
 + break;
 +
 + default:
 + DEBUG7("​!SetC=%x ", pReq->​wValue & 0x0F);
 + RequestOK = 0;
 + break;
 + }
 +
 + if(RequestOK){
 + // Note that the CTRL_IN buffer was cleared in Handle_Ctrl_Out_EP();​
 + Send_Null_Packet(CTRL_IN);​
 + } else {
 + // Indicate we don't like this request
 + Stall_Endpt(CTRL_IN);​
 + Debug_Request(pReq);​
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Handle USB class requests
 +void Class_Request(struct REQUEST *pReq) {
 + short RequestOK = TRUE;
 +
 + switch(pReq->​bRequest){
 +
 + case SET_REPORT:
 + DEBUG4("​SR ");
 + switch(pReq->​wValue >> 8){ // High byte
 + case 1:​ DEBUG4("​I "​);​ break;​ //​ Input
 + case 2:​ DEBUG4("​O "​);​ break;​ //​ Output
 + case 3:​ DEBUG4("​F "​);​ break;​ //​ Feature
 + default:​ DEBUG7("?​ "​);​ break;​
 + }
 + DEBUG4("​RID=%x ", pReq->​wValue & 0x00FF); // Report ID (Low byte)
 + DEBUG4("​I=%Lx ", pReq->​wIndex);​
 + DEBUG4("​wL=%Lx ", pReq->​wLength);​
 +
 + // Setup globals to recieve data on CTRL_OUT
 + LOAD_COUT_LENGTH = pReq->​wLength;​
 + LOAD_COUT_OFFSET = 0;
 +
 + // Acknowledge
 + Send_Null_Packet(CTRL_IN);​
 + break;
 +
 + case GET_REPORT:
 + DEBUG4("​GR ");
 + switch(pReq->​wValue >> 8){ // High byte
 + case 1:​ DEBUG4("​I "​);​ break;​ //​ Input
 + case 2:​ DEBUG4("​O "​);​ break;​ //​ Output
 + case 3:​ DEBUG4("​F "​);​ break;​ //​ Feature
 + default:​ DEBUG7("?​ "​);​ break;​
 + }
 + DEBUG4("​RID=%x ", pReq->​wValue & 0x00FF); // Report ID (Low byte)
 + DEBUG4("​I=%Lx ", pReq->​wIndex);​
 + DEBUG4("​wL=%Lx ", pReq->​wLength);​
 +
 + // Flag that we want to send a report
 + CTRL_IN_SEND_REPORT = TRUE;
 +
 + // Acknowledge
 + Send_Null_Packet(CTRL_IN);​
 + break;
 +
 + default:
 + RequestOK = FALSE;
 + DEBUG7("​\x07"​);​ //​ Bell character (^G)
 + DEBUG7("?​CREQ=%x ", pReq->​bRequest);​
 + break;
 + }
 +
 + if(RequestOK == FALSE){
 + Stall_Endpt(CTRL_OUT);​
 + Debug_Request(pReq);​
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Responsible for sending data in response to setup tokens among other things.
 +// Activties include sending descriptors.
 +#SEPARATE
 +void Handle_Ctrl_In_EP() {
 + unsigned char buffer[2];
 +
 + // Clear interrupt
 + D12_Write(D12_COMMAND,​ READ_ENDPT_STATUS + CTRL_IN);
 + D12_Read(buffer,​ 1);
 + DEBUG1("​LT=%x ", buffer[0]);
 +
 + if (LOAD_CIN_LENGTH > 0) {
 + unsigned char DataLen, DataEnd;
 +
 + // Smaller of "​length of data to send" and "​buffer size"
 + DataLen = (LOAD_CIN_LENGTH > D12_CTRL_BUFFER_SIZE) ? D12_CTRL_BUFFER_SIZE : LOAD_CIN_LENGTH;​
 + DataEnd = LOAD_CIN_OFFSET + DataLen;
 + DEBUG0("​DataLen=%x ", DataLen);
 +
 + D12_Write(D12_COMMAND,​ SELECT_ENDPT + CTRL_IN);
 + D12_Write(D12_COMMAND,​ WRITE_BUFFER);​
 + D12_Write(D12_DATA,​ 0x00); // First byte is reserved
 + D12_Write(D12_DATA,​ DataLen);​ //​ Num of data bytes
 +
 + for(; LOAD_CIN_OFFSET<​DataEnd;​ LOAD_CIN_OFFSET++)
 + {
 + DEBUG0("​%x ", DESCRIPTORS[LOAD_CIN_OFFSET]);​
 + D12_Write(D12_DATA,​ DESCRIPTORS[LOAD_CIN_OFFSET]);​
 + LOAD_CIN_LENGTH--;​
 + }
 + D12_Write(D12_COMMAND,​ VALIDATE_BUFFER);​ //​ Mark the buffer as ready to go!
 +
 + // Are we done?
 + if(LOAD_CIN_LENGTH == 0){
 + // Did the last packet fill the buffer completely?
 + if((DataLen % D12_CTRL_BUFFER_SIZE) == 0){
 + Send_Null_Packet(CTRL_IN);​ //​ Explicity signal end of data
 + }
 + }
 +
 + CTRL_IN_BUSY = TRUE; // Unless something else is pending, the next CTRL_IN interrupt just means the data was sent
 +
 + DEBUG2("​DS ");
 + }
 + else
 + if (CTRL_IN_SEND_REPORT)
 + {
 + // Send_Report returns true if there is not more data to send
 + CTRL_IN_SEND_REPORT = ~(Send_Report(CTRL_IN));​
 + }
 + else
 + if (CTRL_IN_BUSY)
 + {
 + // This interrupt is just the D12 telling us it's emptied its buffer (i.e. sent it to the host)
 + CTRL_IN_BUSY = FALSE;
 + DEBUG0("​ACK "​);​ //​ Actually D12 telling us the buffer was sent
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Interrupt handler for USART hardware data reception
 +#INT_RDA
 +void Handle_UART_Reception() {
 + char c;
 + #use rs232(baud = 9600, xmit = PIN_C6, rcv = PIN_C7) // Hardware USART (GBA)
 + c = getc();
 + #use rs232(baud = 19200, xmit = PIN_C4, rcv = PIN_C5) // Software USART (Debug)
 + DEBUG1("​%c[%x] ", c, c);
 + output_toggle(LED_N);​
 +
 + switch(c){
 + case '​^':​ REPORT_IN.y += 10; break;
 + case '​v':​ REPORT_IN.y -= 10; break;
 + case '<':​ REPORT_IN.x += 10; break;
 + case '>':​ REPORT_IN.x -= 10; break;
 + case '​A':​ REPORT_IN.buttons ^= 0x01; break; // Toggle bit
 + case '​B':​ REPORT_IN.buttons ^= 0x02; break; // Toggle bit
 + case '​s':​ REPORT_IN.buttons ^= 0x04; break; // Toggle bit
 + case '​L':​
 + REPORT_IN.x = rand();
 + REPORT_IN.y = rand();
 + REPORT_IN.buttons = rand();
 + break;
 + case '​S':​
 + REPORT_IN.x = 0;
 + REPORT_IN.y = 0;
 + REPORT_IN.buttons = 0;
 + break;
 + default:
 + DEBUG1("​%c[%x] ", c, c);
 + break;
 + }
 +}
 +
 +//​--------------------------------------------------------
 +// Fill an endpoint with report data.
 +// Should return false if more data is to follow, and should
 +// return true if all data has been sent.
 +//
 +// Note development of this function was never finished,
 +// the author was not successful in getting multi-part
 +// transfers working (i.e. report larger than the endpoint
 +// buffer).
 +//
 +// Also this function seems to return lots of null data
 +// when sending the report though CTRL_IN.
 +short Send_Report(int8 ENDPT) {
 + int8 DataLen;
 + DEBUG2("​SndR ");
 +
 + switch(ENDPT){
 + case CTRL_OUT:
 + case CTRL_IN:
 + DataLen = D12_CTRL_BUFFER_SIZE;​
 + break;
 +
 + case ENDPT2_OUT:
 + case ENDPT2_IN:
 + DataLen = D12_MAIN_BUFFER_SIZE;​
 + break;
 +
 + default:
 + DEBUG7("​!SR DataLen?"​);​
 + return TRUE; // i.e. no more data to send
 + break;
 + }
 +
 + // Smaller of "data left to send" and "size of endpoint buffer"​
 + DataLen = ((sizeof(struct REPORT) - SEND_REPORT_OFFSET) > DataLen) ? DataLen : (sizeof(struct REPORT) - SEND_REPORT_OFFSET);​
 +
 + DEBUG2("​DL=%x ", DataLen);
 +
 + D12_Write(D12_COMMAND,​ READ_ENDPT_STATUS + ENDPT); // Clear interrupt
 + D12_Write(D12_COMMAND,​ SELECT_ENDPT + ENDPT);
 + D12_Write(D12_COMMAND,​ CLEAR_BUFFER);​ //​ (Probably unnecessary)
 + D12_Write(D12_COMMAND,​ WRITE_BUFFER);​
 + D12_Write(D12_DATA,​ 0x00);​ //​ Reserved byte
 + D12_Write(D12_DATA,​ DataLen);
 +
 + DataLen += SEND_REPORT_OFFSET;​
 + for(; SEND_REPORT_OFFSET < DataLen; SEND_REPORT_OFFSET++){
 + D12_Write(D12_DATA,​ *(&​REPORT_IN + SEND_REPORT_OFFSET));​
 + DEBUG2("​%x ",​*(&​REPORT_IN + SEND_REPORT_OFFSET));​
 + }
 + D12_Write(D12_COMMAND,​ VALIDATE_BUFFER);​ //​ Fit to be sent
 +
 + // Are we done?
 + if(SEND_REPORT_OFFSET == sizeof(struct REPORT)){
 + SEND_REPORT_OFFSET = 0;
 + return TRUE;
 + } else {
 + return FALSE;
 + }
 +
 +}
 +</​code>​
project/usb/code/joystick.txt · Last modified: 2007/04/27 01:21 (external edit)