Hi all,
 
I write a small function to modify the uart baud rate at the setup of the link between the stack bluez
and the chip bluetooth. This function is highly inspired from functions in the hciattach.c file
thanks to marcel. This function is specific to the development kit of Semtech-Xemics based on the
SX1441 (bluetooth v1.2).
 
I don't know if that can be usefull but I send you the output of the "diff"
command between the original hciattach.c and thus modified.
 
regards.
 
Michel 
 

------------------ output of the diff command --------------------------------
 
804a805,900
>
>
>
>
>
> /*
>  * Specific initialization for semtech-xemics
>  * development kit based on the SX1441 Bluetooth v1.2
>  *
>  */
> static int xemics(int fd, struct uart_t *u, struct termios *ti)
> {
>  struct timespec tm = {0, 50000};
>  char cmd[13];
>   
>  
>  
>  cmd[0] = HCI_COMMAND_PKT;
>  cmd[1] = 0x0b;   // OCF = Hci_Cmd_xemics_Set_Uart_Baud_Rate
>  cmd[2] = 0xfc;   // OGF = Vendor specific
>  cmd[3] = 0x09;
>  cmd[4] = 0x08;   
>  cmd[5] = 0x02;   
>  cmd[6] = 0x00;
>  
>  
>  
>  /* Xemics set baud rate command */ 
>  /*   BaudRate cmd[7]---cmd[10]
>  /* 115200 = 0x01C200
>   230400 = 0x038400
>   460800 = 0x070800
>   921600 = 0x0E1000
>   
>   Important : cmd[7] = LSB first        */
>   
>  
>  switch (u->speed) {
>  
>  case 115200:
>   cmd[7] = 0x00 ;
>   cmd[8] = 0xC2;
>   cmd[9] = 0x01;
>   cmd[10] = 0x00 ;
>   
>   break;
>  case 230400:
>   cmd[7] = 0x00 ;
>   cmd[8] = 0x84;
>   cmd[9] = 0x03;
>   cmd[10] = 0x00 ;
>   break;
>  case 460800:
>   cmd[7] = 0x00;
>   cmd[8] = 0x08;
>   cmd[9] = 0x07;
>   cmd[10] = 0x00;
>   break;
>  case 921600:
>   cmd[7] = 0x00;
>   cmd[8] = 0x10;
>   cmd[9] = 0x0E;
>   cmd[10] = 0x00 ;
>   break;
>  default:
>   cmd[7] = 0x00 ;
>   cmd[8] = 0xC2;
>   cmd[9] = 0x01;
>   cmd[10] = 0x00 ;
>   
>   u->speed = 115200;
>   break;
>  }
>  
>    
>  cmd[11] = 0xb1;   
>  cmd[12] = 0x03;
>
>  
>  /* Send  uart rate */
>  if (write(fd, cmd, 13) != 13) {
>   perror("Can't write reset cmd.");
>   return -1;
>  }
>
>  nanosleep(&tm, NULL);
>
>
>
>  
>  return 0;
> }
>
>
>
>
857a954,957
>  /* Semtech Xemics development kit  based on the SX1441 (bluetooth chip v1.2) */
>  { "xemics",      0x0000, 0x0000, HCI_UART_H4,   115200, 115200, FLOW_CTL , xemics   },
>  
>