From 7fbb75928749b74a0964ad159159066967191243 Mon Sep 17 00:00:00 2001 From: Dean Camera Date: Mon, 31 Aug 2009 07:48:32 +0000 Subject: Changed the parameters and behaviour of the USB_GetDeviceConfigDescriptor() function so that it now performs size checks and data validations internally, to simplify user code. --- Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c | 39 +++++++++------------- 1 file changed, 16 insertions(+), 23 deletions(-) (limited to 'Demos/Host/LowLevel/PrinterHost') diff --git a/Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c b/Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c index d4eaff94a..22d84c5aa 100644 --- a/Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c +++ b/Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c @@ -36,32 +36,26 @@ uint8_t PrinterAltSetting; uint8_t ProcessConfigurationDescriptor(void) { - uint8_t* ConfigDescriptorData; - uint16_t ConfigDescriptorSize; - uint8_t ErrorCode; + uint8_t ConfigDescriptorData[512]; + uint8_t* CurrConfigLocation = ConfigDescriptorData; + uint16_t CurrConfigBytesRem; uint8_t FoundEndpoints = 0; - - /* Get Configuration Descriptor size from the device */ - if (USB_GetDeviceConfigDescriptor(1, &ConfigDescriptorSize, NULL) != HOST_SENDCONTROL_Successful) - return ControlError; - - /* Ensure that the Configuration Descriptor isn't too large */ - if (ConfigDescriptorSize > MAX_CONFIG_DESCRIPTOR_SIZE) - return DescriptorTooLarge; - - /* Allocate enough memory for the entire config descriptor */ - ConfigDescriptorData = alloca(ConfigDescriptorSize); /* Retrieve the entire configuration descriptor into the allocated buffer */ - USB_GetDeviceConfigDescriptor(1, &ConfigDescriptorSize, ConfigDescriptorData); - - /* Validate returned data - ensure first entry is a configuration header descriptor */ - if (DESCRIPTOR_TYPE(ConfigDescriptorData) != DTYPE_Configuration) - return InvalidConfigDataReturned; + switch (USB_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData))) + { + case HOST_GETCONFIG_Successful: + break; + case HOST_GETCONFIG_InvalidData: + return InvalidConfigDataReturned; + case HOST_GETCONFIG_BuffOverflow: + return DescriptorTooLarge; + default: + return ControlError; + } /* Get the printer interface from the configuration descriptor */ - if ((ErrorCode = USB_GetNextDescriptorComp(&ConfigDescriptorSize, &ConfigDescriptorData, - DComp_NextBidirectionalPrinterInterface))) + if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DComp_NextBidirectionalPrinterInterface)) { /* Descriptor not found, error out */ return NoInterfaceFound; @@ -74,8 +68,7 @@ uint8_t ProcessConfigurationDescriptor(void) while (FoundEndpoints != ((1 << PRINTER_DATA_OUT_PIPE) | (1 << PRINTER_DATA_IN_PIPE))) { /* Fetch the next bulk endpoint from the current printer interface */ - if ((ErrorCode = USB_GetNextDescriptorComp(&ConfigDescriptorSize, &ConfigDescriptorData, - DComp_NextInterfaceBulkDataEndpoint))) + if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DComp_NextInterfaceBulkDataEndpoint)) { /* Descriptor not found, error out */ return NoEndpointFound; -- cgit v1.2.3