/******************************************************************************* Copyright 2016 Microchip Technology Inc. (www.microchip.com) Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. To request to license the code under the MLA license (www.microchip.com/mla_license), please contact mla_licensing@microchip.com *******************************************************************************/ /******************************************************************** -usb_descriptors.c- ------------------------------------------------------------------- Filling in the descriptor values in the usb_descriptors.c file: ------------------------------------------------------------------- [Device Descriptors] The device descriptor is defined as a USB_DEVICE_DESCRIPTOR type. This type is defined in usb_ch9.h Each entry into this structure needs to be the correct length for the data type of the entry. [Configuration Descriptors] The configuration descriptor was changed in v2.x from a structure to a uint8_t array. Given that the configuration is now a byte array each byte of multi-byte fields must be listed individually. This means that for fields like the total size of the configuration where the field is a 16-bit value "64,0," is the correct entry for a configuration that is only 64 bytes long and not "64," which is one too few bytes. The configuration attribute must always have the _DEFAULT definition at the minimum. Additional options can be ORed to the _DEFAULT attribute. Available options are _SELF and _RWU. These definitions are defined in the usb_device.h file. The _SELF tells the USB host that this device is self-powered. The _RWU tells the USB host that this device supports Remote Wakeup. [Endpoint Descriptors] Like the configuration descriptor, the endpoint descriptors were changed in v2.x of the stack from a structure to a uint8_t array. As endpoint descriptors also has a field that are multi-byte entities, please be sure to specify both bytes of the field. For example, for the endpoint size an endpoint that is 64 bytes needs to have the size defined as "64,0," instead of "64," Take the following example: // Endpoint Descriptor // 0x07, //the size of this descriptor // USB_DESCRIPTOR_ENDPOINT, //Endpoint Descriptor _EP02_IN, //EndpointAddress _INT, //Attributes 0x08,0x00, //size (note: 2 bytes) 0x02, //Interval The first two parameters are self-explanatory. They specify the length of this endpoint descriptor (7) and the descriptor type. The next parameter identifies the endpoint, the definitions are defined in usb_device.h and has the following naming convention: _EP<##>_ where ## is the endpoint number and dir is the direction of transfer. The dir has the value of either 'OUT' or 'IN'. The next parameter identifies the type of the endpoint. Available options are _BULK, _INT, _ISO, and _CTRL. The _CTRL is not typically used because the default control transfer endpoint is not defined in the USB descriptors. When _ISO option is used, addition options can be ORed to _ISO. Example: _ISO|_AD|_FE This describes the endpoint as an isochronous pipe with adaptive and feedback attributes. See usb_device.h and the USB specification for details. The next parameter defines the size of the endpoint. The last parameter in the polling interval. ------------------------------------------------------------------- Adding a USB String ------------------------------------------------------------------- A string descriptor array should have the following format: rom struct{byte bLength;byte bDscType;word string[size];}sdxxx={ sizeof(sdxxx),DSC_STR,}; The above structure provides a means for the C compiler to calculate the length of string descriptor sdxxx, where xxx is the index number. The first two bytes of the descriptor are descriptor length and type. The rest are string texts which must be in the unicode format. The unicode format is achieved by declaring each character as a word type. The whole text string is declared as a word array with the number of characters equals to . has to be manually counted and entered into the array declaration. Let's study this through an example: if the string is "USB" , then the string descriptor should be: (Using index 02) rom struct{byte bLength;byte bDscType;word string[3];}sd002={ sizeof(sd002),DSC_STR,'U','S','B'}; A USB project may have multiple strings and the firmware supports the management of multiple strings through a look-up table. The look-up table is defined as: rom const unsigned char *rom USB_SD_Ptr[]={&sd000,&sd001,&sd002}; The above declaration has 3 strings, sd000, sd001, and sd002. Strings can be removed or added. sd000 is a specialized string descriptor. It defines the language code, usually this is US English (0x0409). The index of the string must match the index position of the USB_SD_Ptr array, &sd000 must be in position USB_SD_Ptr[0], &sd001 must be in position USB_SD_Ptr[1] and so on. The look-up table USB_SD_Ptr is used by the get string handler function. ------------------------------------------------------------------- The look-up table scheme also applies to the configuration descriptor. A USB device may have multiple configuration descriptors, i.e. CFG01, CFG02, etc. To add a configuration descriptor, user must implement a structure similar to CFG01. The next step is to add the configuration descriptor name, i.e. cfg01, cfg02,.., to the look-up table USB_CD_Ptr. USB_CD_Ptr[0] is a dummy place holder since configuration 0 is the un-configured state according to the definition in the USB specification. ********************************************************************/ /********************************************************************* * Descriptor specific type definitions are defined in: * usb_device.h * * Configuration options are defined in: * usb_config.h ********************************************************************/ #ifndef __USB_DESCRIPTORS_C #define __USB_DESCRIPTORS_C /** INCLUDES *******************************************************/ #include "usb.h" #include "usb_device_cdc.h" /** CONSTANTS ******************************************************/ #if defined(__18CXX) #pragma romdata #endif /* Device Descriptor */ const USB_DEVICE_DESCRIPTOR device_dsc= { 0x12, // Size of this descriptor in bytes USB_DESCRIPTOR_DEVICE, // DEVICE descriptor type 0x0200, // USB Spec Release Number in BCD format CDC_DEVICE, // Class Code 0x00, // Subclass code 0x00, // Protocol code USB_EP0_BUFF_SIZE, // Max packet size for EP0, see usb_config.h 0x04D8, // Vendor ID 0x000A, // Product ID: CDC RS-232 Emulation Demo 0x0100, // Device release number in BCD format 0x01, // Manufacturer string index 0x02, // Product string index 0x00, // Device serial number string index 0x01 // Number of possible configurations }; /* Configuration 1 Descriptor */ const uint8_t configDescriptor1[]={ /* Configuration Descriptor */ 0x09,//sizeof(USB_CFG_DSC), // Size of this descriptor in bytes USB_DESCRIPTOR_CONFIGURATION, // CONFIGURATION descriptor type 67,0, // Total length of data for this cfg 2, // Number of interfaces in this cfg 1, // Index value of this configuration 0, // Configuration string index _DEFAULT | _SELF, // Attributes, see usb_device.h 50, // Max power consumption (2X mA) /* Interface Descriptor */ 9,//sizeof(USB_INTF_DSC), // Size of this descriptor in bytes USB_DESCRIPTOR_INTERFACE, // INTERFACE descriptor type 0, // Interface Number 0, // Alternate Setting Number 1, // Number of endpoints in this intf COMM_INTF, // Class code ABSTRACT_CONTROL_MODEL, // Subclass code V25TER, // Protocol code 0, // Interface string index /* CDC Class-Specific Descriptors */ sizeof(USB_CDC_HEADER_FN_DSC), CS_INTERFACE, DSC_FN_HEADER, 0x10,0x01, sizeof(USB_CDC_ACM_FN_DSC), CS_INTERFACE, DSC_FN_ACM, USB_CDC_ACM_FN_DSC_VAL, sizeof(USB_CDC_UNION_FN_DSC), CS_INTERFACE, DSC_FN_UNION, CDC_COMM_INTF_ID, CDC_DATA_INTF_ID, sizeof(USB_CDC_CALL_MGT_FN_DSC), CS_INTERFACE, DSC_FN_CALL_MGT, 0x00, CDC_DATA_INTF_ID, /* Endpoint Descriptor */ //sizeof(USB_EP_DSC),DSC_EP,_EP02_IN,_INT,CDC_INT_EP_SIZE,0x02, 0x07,/*sizeof(USB_EP_DSC)*/ USB_DESCRIPTOR_ENDPOINT, //Endpoint Descriptor _EP01_IN, //EndpointAddress _INTERRUPT, //Attributes 0x0A,0x00, //size 0x02, //Interval /* Interface Descriptor */ 9,//sizeof(USB_INTF_DSC), // Size of this descriptor in bytes USB_DESCRIPTOR_INTERFACE, // INTERFACE descriptor type 1, // Interface Number 0, // Alternate Setting Number 2, // Number of endpoints in this intf DATA_INTF, // Class code 0, // Subclass code NO_PROTOCOL, // Protocol code 0, // Interface string index /* Endpoint Descriptor */ //sizeof(USB_EP_DSC),DSC_EP,_EP03_OUT,_BULK,CDC_BULK_OUT_EP_SIZE,0x00, 0x07,/*sizeof(USB_EP_DSC)*/ USB_DESCRIPTOR_ENDPOINT, //Endpoint Descriptor _EP02_OUT, //EndpointAddress _BULK, //Attributes 0x40,0x00, //size 0x00, //Interval /* Endpoint Descriptor */ //sizeof(USB_EP_DSC),DSC_EP,_EP03_IN,_BULK,CDC_BULK_IN_EP_SIZE,0x00 0x07,/*sizeof(USB_EP_DSC)*/ USB_DESCRIPTOR_ENDPOINT, //Endpoint Descriptor _EP02_IN, //EndpointAddress _BULK, //Attributes 0x40,0x00, //size 0x00, //Interval }; //Language code string descriptor const struct{uint8_t bLength;uint8_t bDscType;uint16_t string[1];}sd000={ sizeof(sd000),USB_DESCRIPTOR_STRING,{0x0409}}; //Manufacturer string descriptor const struct{uint8_t bLength;uint8_t bDscType;uint16_t string[25];}sd001={ sizeof(sd001),USB_DESCRIPTOR_STRING, {'M','i','c','r','o','c','h','i','p',' ', 'T','e','c','h','n','o','l','o','g','y',' ','I','n','c','.' }}; //Product string descriptor const struct{uint8_t bLength;uint8_t bDscType;uint16_t string[25];}sd002={ sizeof(sd002),USB_DESCRIPTOR_STRING, {'C','D','C',' ','R','S','-','2','3','2',' ', 'E','m','u','l','a','t','i','o','n',' ','D','e','m','o'} }; //Serial number string descriptor. If a serial number string is implemented, //it should be unique for every single device coming off the production assembly //line. Plugging two devices with the same serial number into a computer //simultaneously will cause problems (in extreme cases BSOD). //Note: Common OSes put restrictions on the possible values that are allowed. //For best OS compatibility, the serial number string should only consist //of UNICODE encoded numbers 0 through 9 and capital letters A through F. //ROM struct{BYTE bLength;BYTE bDscType;WORD string[10];}sd003={ //sizeof(sd003),USB_DESCRIPTOR_STRING, //{'0','1','2','3','4','5','6','7','8','9'}}; //Array of configuration descriptors const uint8_t *const USB_CD_Ptr[]= { (const uint8_t *const)&configDescriptor1 }; //Array of string descriptors const uint8_t *const USB_SD_Ptr[USB_NUM_STRING_DESCRIPTORS]= { (const uint8_t *const)&sd000, (const uint8_t *const)&sd001, (const uint8_t *const)&sd002 //(const uint8_t *const)&sd003 //uncomment if implementing a serial number string descriptor named sd003 }; #if defined(__18CXX) #pragma code #endif #endif /** EOF usb_descriptors.c ****************************************************/