Diff: usbdevice.cpp

Revision:

0:237d5ef643e9

diff -r 000000000000 -r 237d5ef643e9 usbdevice.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/usbdevice.cpp	Fri May 11 13:35:59 2012 +0000
@@ -0,0 +1,532 @@
+/* usbdevice.cpp */
+/* Generic USB device */
+/* Copyright (c) Phil Wright 2008 */
+
+#include "mbed.h"
+#include "usbdevice.h"
+
+/* Standard requests */
+#define GET_STATUS        (0)
+#define CLEAR_FEATURE     (1)
+#define SET_FEATURE       (3)
+#define SET_ADDRESS       (5)
+#define GET_DESCRIPTOR    (6)
+#define SET_DESCRIPTOR    (7)
+#define GET_CONFIGURATION (8)
+#define SET_CONFIGURATION (9)
+#define GET_INTERFACE     (10)
+#define SET_INTERFACE     (11)
+
+/* Device status */
+#define DEVICE_STATUS_SELF_POWERED  (1<<0)
+#define DEVICE_STATUS_REMOTE_WAKEUP (1<<1)
+
+/* Endpoint status */
+#define ENDPOINT_STATUS_HALT        (1<<0)
+
+/* Standard feature selectors */
+#define DEVICE_REMOTE_WAKEUP        (1)
+#define ENDPOINT_HALT               (0)
+
+/* Macro to convert wIndex endpoint number to physical endpoint number */
+#define WINDEX_TO_PHYSICAL(endpoint) (((endpoint & 0x0f) << 1) + ((endpoint & 0x80) ? 1 : 0))
+
+CONTROL_TRANSFER transfer;
+USB_DEVICE device;
+    
+usbdevice::usbdevice()
+{
+    /* Set initial device state */
+    device.state = POWERED;
+    device.configuration = 0;
+    device.suspended = false;
+    
+    /* Set the maximum packet size for the control endpoints */
+    realiseEndpoint(EP0IN, MAX_PACKET_SIZE_EP0);
+    realiseEndpoint(EP0OUT, MAX_PACKET_SIZE_EP0);
+    
+    /* Enable endpoint events for EP0 */
+    enableEndpointEvent(EP0IN);
+    enableEndpointEvent(EP0OUT);
+}
+
+void usbdevice::endpointEventEP0Setup(void)
+{
+    /* Endpoint 0 setup event */
+    if (!controlSetup())
+    {    
+        /* Protocol stall; this will stall both endpoints */
+        stallEndpoint(EP0OUT);
+    }
+}
+
+void usbdevice::endpointEventEP0Out(void)
+{
+    /* Endpoint 0 OUT data event */
+    if (!controlOut())
+    {    
+        /* Protocol stall; this will stall both endpoints */
+        stallEndpoint(EP0OUT);
+    }    
+}
+
+void usbdevice::endpointEventEP0In(void)
+{
+    /* Endpoint 0 IN data event */
+    if (!controlIn())
+    {    
+        /* Protocol stall; this will stall both endpoints */
+        stallEndpoint(EP0OUT);
+    }
+}
+
+void usbdevice::deviceEventReset(void)
+{
+    device.state = DEFAULT;
+    device.configuration = 0;
+    device.suspended = false;
+}
+
+void usbdevice::decodeSetupPacket(unsigned char *data, SETUP_PACKET *packet)
+{
+    /* Fill in the elements of a SETUP_PACKET structure from raw data */
+    packet->bmRequestType.dataTransferDirection = (data[0] & 0x80) >> 7;
+    packet->bmRequestType.Type = (data[0] & 0x60) >> 5;
+    packet->bmRequestType.Recipient = data[0] & 0x1f;
+    packet->bRequest = data[1];
+    packet->wValue = (data[2] | (unsigned short)data[3] << 8);
+    packet->wIndex = (data[4] | (unsigned short)data[5] << 8);
+    packet->wLength = (data[6] | (unsigned short)data[7] << 8);
+}
+
+bool usbdevice::controlSetup(void)
+{
+    /* Control transfer setup stage */
+    unsigned char buffer[MAX_PACKET_SIZE_EP0];
+    unsigned long count;
+
+    count = endpointRead(EP0OUT, buffer);
+    
+    /* Must be 8 bytes of data */
+    if (count != 8)
+    {    
+        return false;
+    }
+    
+    /* Initialise control transfer state */
+    decodeSetupPacket(buffer, &transfer.setup);        
+    transfer.ptr = NULL;
+    transfer.remaining = 0;
+    transfer.direction = 0;
+    transfer.zlp = false;
+    
+    /* Process request */
+    if (!requestSetup())
+    {
+        return false;
+    }
+
+    /* Check transfer size and direction  */
+    if (transfer.setup.wLength>0)
+    {
+        if (transfer.setup.bmRequestType.dataTransferDirection==DEVICE_TO_HOST)
+        {
+            /* IN data stage is required */
+            if (transfer.direction != DEVICE_TO_HOST)
+            {
+                return false;
+            }
+            
+            /* Transfer must be less than or equal to the size requested by the host */
+            if (transfer.remaining > transfer.setup.wLength)
+            {
+                transfer.remaining = transfer.setup.wLength;
+            }
+        }
+        else
+        {
+            /* OUT data stage is required */
+            if (transfer.direction != HOST_TO_DEVICE)
+            {
+                return false;
+            }
+            
+            /* Transfer must be equal to the size requested by the host */
+            if (transfer.remaining != transfer.setup.wLength)
+            {
+                return false;
+            }
+        }
+    }
+    else
+    {
+        /* No data stage; transfer size must be zero */
+        if (transfer.remaining != 0)
+        {
+            return false;
+        }
+    }                
+    
+    /* Data or status stage if applicable */
+    if (transfer.setup.wLength>0)
+    {
+        if (transfer.setup.bmRequestType.dataTransferDirection==DEVICE_TO_HOST)
+        {            
+            /* Check if we'll need to send a zero length packet at the end of this transfer */
+            if (transfer.setup.wLength > transfer.remaining)
+            {
+                /* Device wishes to transfer less than host requested */
+                if ((transfer.remaining % MAX_PACKET_SIZE_EP0) == 0)
+                {
+                    /* Transfer is a multiple of EP0 max packet size */
+                    transfer.zlp = true;
+                }            
+            }
+            
+            /* IN stage */
+            controlIn();
+        }
+    }
+    else
+    {
+        /* Status stage */
+        endpointWrite(EP0IN, NULL, 0);
+    }
+    
+    return true;
+}
+
+bool usbdevice::controlOut(void)
+{    
+    /* Control transfer data OUT stage */
+    unsigned char buffer[MAX_PACKET_SIZE_EP0];
+    unsigned long packetSize;
+
+    /* Check we should be transferring data OUT */
+    if (transfer.direction != HOST_TO_DEVICE)
+    {
+        return false;
+    }
+    
+    /* Read from endpoint */
+    packetSize = endpointRead(EP0OUT, buffer);
+    
+    /* Check if transfer size is valid */
+    if (packetSize > transfer.remaining)
+    {
+        /* Too big */
+        return false;
+    }
+    
+    /* Update transfer */
+    transfer.ptr += packetSize;
+    transfer.remaining -= packetSize;
+    
+    /* Check if transfer has completed */
+    if (transfer.remaining == 0)
+    {
+        /* Process request */        
+        if (!requestOut())
+        {
+            return false;
+        }
+        
+        /* Status stage */
+        endpointWrite(EP0IN, NULL, 0);
+    }
+    
+    return true;
+}
+
+bool usbdevice::controlIn(void)
+{
+    /* Control transfer data IN stage */    
+    unsigned packetSize;
+    
+    /* Check if transfer has completed (status stage transactions also have transfer.remaining == 0) */
+    if (transfer.remaining == 0)
+    {
+        if (transfer.zlp)
+        {
+            /* Send zero length packet */
+            endpointWrite(EP0IN, NULL, 0);
+            transfer.zlp = false;
+        }
+        
+        /* Completed */
+        return true;
+    }
+    
+    /* Check we should be transferring data IN */
+    if (transfer.direction != DEVICE_TO_HOST)
+    {
+        return false;
+    }
+    
+    packetSize = transfer.remaining;
+    
+    if (packetSize > MAX_PACKET_SIZE_EP0)
+    {
+        packetSize = MAX_PACKET_SIZE_EP0;
+    }
+    
+    /* Write to endpoint */
+    endpointWrite(EP0IN, transfer.ptr, packetSize);
+    
+    /* Update transfer */
+    transfer.ptr += packetSize;
+    transfer.remaining -= packetSize;
+    
+    return true;
+}
+
+bool usbdevice::requestSetup(void)
+{
+    bool success = false;
+
+    /* Process standard requests */
+    if ((transfer.setup.bmRequestType.Type == STANDARD_TYPE))
+    {
+        switch (transfer.setup.bRequest)
+        {
+             case GET_STATUS:
+                 success = requestGetStatus();
+                 break;
+             case CLEAR_FEATURE:
+                 success = requestClearFeature();
+                 break;
+             case SET_FEATURE:
+                 success = requestSetFeature();
+                 break;
+             case SET_ADDRESS:
+                success = requestSetAddress();
+                 break;    
+             case GET_DESCRIPTOR:
+                 success = requestGetDescriptor();
+                 break;
+             case SET_DESCRIPTOR:
+                 /* TODO: Support is optional, not implemented here */
+                 success = false;
+                 break;
+             case GET_CONFIGURATION:
+                 success = requestGetConfiguration();
+                 break;
+             case SET_CONFIGURATION:
+                 success = requestSetConfiguration();
+                 break;
+             case GET_INTERFACE:
+                 success = requestGetInterface();
+                 break;
+             case SET_INTERFACE:
+                 success = requestSetInterface();
+                 break;
+             default:
+                 break;
+        }
+    }
+    
+    return success;
+}
+
+bool usbdevice::requestOut(void)
+{
+    return true;
+}
+
+bool usbdevice::requestSetAddress(void)
+{
+    /* Set the device address */
+    setAddress(transfer.setup.wValue);    
+    
+    if (transfer.setup.wValue == 0)
+    {
+        device.state = DEFAULT;
+    }
+    else
+    {
+        device.state = ADDRESS;
+    }
+        
+    return true;
+}
+
+bool usbdevice::requestSetConfiguration(void)
+{
+    /* Set the device configuration */    
+    if (transfer.setup.wValue == 0)
+    {
+        /* Not configured */
+        unconfigureDevice();
+        device.state = ADDRESS;
+    }
+    else
+    {
+        configureDevice();
+        device.state = CONFIGURED;
+    }
+    
+    /* TODO: We do not currently support multiple configurations, just keep a record of the configuration value */
+    device.configuration = transfer.setup.wValue;
+    
+    return true;
+}
+
+bool usbdevice::requestGetConfiguration(void)
+{
+    /* Send the device configuration */
+    transfer.ptr = &device.configuration;
+    transfer.remaining = sizeof(device.configuration);
+    transfer.direction = DEVICE_TO_HOST;
+    return true;
+}
+
+bool usbdevice::requestGetInterface(void)
+{
+    static unsigned char alternateSetting;
+    
+    /* Return the selected alternate setting for an interface */
+    
+    if (device.state != CONFIGURED)
+    {
+        return false;
+    }
+    
+    /* TODO: We currently do not support alternate settings so always return zero */
+    /* TODO: Should check that the interface number is valid */    
+    alternateSetting = 0;
+    
+    /* Send the alternate setting */
+    transfer.ptr = &alternateSetting;
+    transfer.remaining = sizeof(alternateSetting);
+    transfer.direction = DEVICE_TO_HOST;
+    return true;    
+}
+
+bool usbdevice::requestSetInterface(void)
+{
+    /* TODO: We currently do not support alternate settings, return false */
+    return false;
+}    
+
+bool usbdevice::requestSetFeature()
+{
+    bool success = false;
+    
+    if (device.state != CONFIGURED)
+    {
+        /* Endpoint or interface must be zero */
+        if (transfer.setup.wIndex != 0)
+        {
+            return false;
+        }
+    }
+    
+    switch (transfer.setup.bmRequestType.Recipient)
+    {
+        case DEVICE_RECIPIENT:
+            /* TODO: Remote wakeup feature not supported */
+            break;
+        case ENDPOINT_RECIPIENT:    
+            if (transfer.setup.wValue == ENDPOINT_HALT)
+            {
+                /* TODO: We should check that the endpoint number is valid */
+                stallEndpoint(WINDEX_TO_PHYSICAL(transfer.setup.wIndex));
+                success = true;
+            }            
+            break;
+        default:
+            break;
+    }
+    
+    return success;
+}
+
+bool usbdevice::requestClearFeature()
+{
+    bool success = false;
+    
+    if (device.state != CONFIGURED)
+    {
+        /* Endpoint or interface must be zero */
+        if (transfer.setup.wIndex != 0)
+        {
+            return false;
+        }
+    }
+    
+    switch (transfer.setup.bmRequestType.Recipient)
+    {
+        case DEVICE_RECIPIENT:
+            /* TODO: Remote wakeup feature not supported */
+            break;
+        case ENDPOINT_RECIPIENT:
+            /* TODO: We should check that the endpoint number is valid */    
+            if (transfer.setup.wValue == ENDPOINT_HALT)
+            {
+                unstallEndpoint(WINDEX_TO_PHYSICAL(transfer.setup.wIndex));
+                success = true;
+            }            
+            break;
+        default:
+            break;
+    }
+    
+    return success;
+}
+
+bool usbdevice::requestGetStatus(void)
+{
+    static unsigned short status;
+    bool success = false;
+    
+    if (device.state != CONFIGURED)
+    {
+        /* Endpoint or interface must be zero */
+        if (transfer.setup.wIndex != 0)
+        {
+            return false;
+        }
+    }
+    
+    switch (transfer.setup.bmRequestType.Recipient)
+    {
+        case DEVICE_RECIPIENT:
+            /* TODO: Currently only supports self powered devices */
+            status = DEVICE_STATUS_SELF_POWERED;
+            success = true;
+            break;
+        case INTERFACE_RECIPIENT:
+            status = 0;
+            success = true;
+            break;
+        case ENDPOINT_RECIPIENT:
+            /* TODO: We should check that the endpoint number is valid */
+            if (getEndpointStallState(WINDEX_TO_PHYSICAL(transfer.setup.wIndex)))
+            {
+                status = ENDPOINT_STATUS_HALT;
+            }
+            else
+            {
+                status = 0;
+            } 
+            success = true;
+            break;
+        default:
+            break;
+    }
+    
+    if (success)
+    {
+        /* Send the status */ 
+        transfer.ptr = (unsigned char *)&status; /* Assumes little endian */
+        transfer.remaining = sizeof(status); 
+        transfer.direction = DEVICE_TO_HOST;
+    }
+    
+    return success;
+}
+
+bool usbdevice::requestGetDescriptor(void)
+{
+    return false;
+}
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