usbh_hid_parser.c

00001 /**
00002   ******************************************************************************
00003   * @file    usbh_hid_parser.c
00004   * @author  MCD Application Team
00005   * @version V3.2.2
00006   * @date    07-July-2015
00007   * @brief   This file is the HID Layer Handlers for USB Host HID class.
00008   ******************************************************************************
00009   * @attention
00010   *
00011   * <h2><center>&copy; COPYRIGHT 2015 STMicroelectronics</center></h2>
00012   *
00013   * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
00014   * You may not use this file except in compliance with the License.
00015   * You may obtain a copy of the License at:
00016   *
00017   *        http://www.st.com/software_license_agreement_liberty_v2
00018   *
00019   * Unless required by applicable law or agreed to in writing, software 
00020   * distributed under the License is distributed on an "AS IS" BASIS, 
00021   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00022   * See the License for the specific language governing permissions and
00023   * limitations under the License.
00024   *
00025   ******************************************************************************
00026   */
00027 /* Includes ------------------------------------------------------------------*/
00028 #include "usbh_hid_parser.h"
00029 
00030 
00031 /** @addtogroup USBH_LIB
00032   * @{
00033   */
00034 
00035 /** @addtogroup USBH_CLASS
00036   * @{
00037   */
00038 
00039 /** @addtogroup USBH_HID_CLASS
00040   * @{
00041   */
00042   
00043 /** @defgroup USBH_HID_PARSER 
00044   * @brief    This file includes HID parsers for USB Host HID class.
00045   * @{
00046   */ 
00047 
00048 /** @defgroup USBH_HID_PARSER_Private_TypesDefinitions
00049   * @{
00050   */ 
00051 /**
00052   * @}
00053   */ 
00054 
00055 
00056 /** @defgroup USBH_HID_PARSER_Private_Defines
00057   * @{
00058   */ 
00059 /**
00060   * @}
00061   */ 
00062 
00063 
00064 /** @defgroup USBH_HID_PARSER_Private_Macros
00065   * @{
00066   */ 
00067 /**
00068   * @}
00069   */ 
00070 
00071 /** @defgroup USBH_HID_PARSER_Private_FunctionPrototypes
00072   * @{
00073   */ 
00074 
00075 /**
00076   * @}
00077   */ 
00078 
00079 
00080 /** @defgroup USBH_HID_PARSER_Private_Variables
00081   * @{
00082   */
00083 
00084 /**
00085   * @}
00086   */ 
00087 
00088 
00089 /** @defgroup USBH_HID_PARSER_Private_Functions
00090   * @{
00091   */ 
00092 
00093 /**
00094   * @brief  HID_ReadItem 
00095   *         The function read a report item.
00096   * @param  ri: report item
00097   * @param  ndx: report index
00098 * @retval status (0 : fail / otherwise: item value)
00099   */
00100 uint32_t HID_ReadItem(HID_Report_ItemTypedef *ri, uint8_t ndx)
00101 {
00102   uint32_t val=0;
00103   uint32_t x=0;
00104   uint32_t bofs;
00105   uint8_t *data=ri->data;
00106   uint8_t shift=ri->shift;
00107   
00108   /* get the logical value of the item */
00109   
00110   /* if this is an array, wee may need to offset ri->data.*/
00111   if (ri->count > 0)
00112   { 
00113     /* If app tries to read outside of the array. */
00114     if (ri->count <= ndx)
00115     {
00116       return(0);
00117     }
00118     
00119     /* calculate bit offset */
00120     bofs = ndx*ri->size;
00121     bofs += shift;
00122     /* calculate byte offset + shift pair from bit offset. */    
00123     data+=bofs/8;
00124     shift=(uint8_t)(bofs%8);
00125   }
00126   /* read data bytes in little endian order */
00127   for(x=0; x < ((ri->size & 0x7) ? (ri->size/8)+1 : (ri->size/8)); x++)
00128   {
00129     val=(uint32_t)(*data << (x*8));
00130   }    
00131   val=(val >> shift) & ((1<<ri->size)-1);
00132   
00133   if (val < ri->logical_min || val > ri->logical_max)
00134   {
00135     return(0);
00136   }
00137   
00138   /* convert logical value to physical value */
00139   /* See if the number is negative or not. */
00140   if ((ri->sign) && (val & (1<<(ri->size-1))))
00141   {
00142     /* yes, so sign extend value to 32 bits. */
00143     int vs=(int)((-1 & ~((1<<(ri->size))-1)) | val);
00144     
00145     if(ri->resolution == 1)
00146     {
00147       return((uint32_t)vs);
00148     }
00149     return((uint32_t)(vs*ri->resolution));
00150   }
00151   else
00152   {
00153     if(ri->resolution == 1)
00154     {
00155       return(val);
00156     }
00157     return(val*ri->resolution);    
00158   }  
00159 }
00160 
00161 /**
00162   * @brief  HID_WriteItem 
00163   *         The function write a report item.
00164   * @param  ri: report item
00165   * @param  ndx: report index
00166   * @retval status (1: fail/ 0 : Ok)
00167   */
00168 uint32_t HID_WriteItem(HID_Report_ItemTypedef *ri, uint32_t value, uint8_t ndx)
00169 {
00170   uint32_t x;
00171   uint32_t mask;
00172   uint32_t bofs;
00173   uint8_t *data=ri->data;
00174   uint8_t shift=ri->shift;
00175   
00176   if (value < ri->physical_min || value > ri->physical_max)  
00177   {
00178     return(1);
00179   }
00180   
00181     /* if this is an array, wee may need to offset ri->data.*/
00182   if (ri->count > 0)
00183   { 
00184     /* If app tries to read outside of the array. */
00185     if (ri->count >= ndx)
00186     {
00187       return(0);
00188     }
00189     /* calculate bit offset */
00190     bofs = ndx*ri->size;
00191     bofs += shift;
00192     /* calculate byte offset + shift pair from bit offset. */    
00193     data+=bofs/8;
00194     shift=(uint8_t)(bofs%8);
00195 
00196   }
00197 
00198   /* Convert physical value to logical value. */  
00199   if (ri->resolution != 1)
00200   {
00201     value=value/ri->resolution;
00202   }
00203 
00204   /* Write logical value to report in little endian order. */
00205   mask=(uint32_t)((1<<ri->size)-1);
00206   value = (value & mask) << shift;
00207   
00208   for(x=0; x < ((ri->size & 0x7) ? (ri->size/8)+1 : (ri->size/8)); x++)
00209   {
00210     *(ri->data+x)=(uint8_t)((*(ri->data+x) & ~(mask>>(x*8))) | ((value>>(x*8)) & (mask>>(x*8))));
00211   }
00212   return(0);
00213 }
00214 
00215 /**
00216   * @}
00217   */ 
00218 
00219 /**
00220   * @}
00221   */ 
00222 
00223 /**
00224   * @}
00225   */
00226 
00227 /**
00228   * @}
00229   */
00230 
00231 
00232 /**
00233   * @}
00234   */
00235 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/