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Hardware Configuration in mach-W5300e-1.c

아래 경로의 Target board 설정파일인 mach-w5300e01.c를 이용하여 W5500관련한 Hardware관련 Configuration을 한다.
linux/arch/arm/mach-s3c2410/

• SPI pin configuration

  //static void __init w5300e01_init(void)
  
  /* W5500 SPI pin */
  s3c2410_gpio_cfgpin(S3C2410_GPF1, S3C2410_GPF1_OUTP); //SCS
  s3c2410_gpio_setpin(S3C2410_GPF1, 1); //low active
  s3c2410_gpio_cfgpin(S3C2410_GPE13, S3C2410_GPE13_SPICLK0); //SCLK
  s3c2410_gpio_setpin(S3C2410_GPE13, 1);
  s3c2410_gpio_cfgpin(S3C2410_GPE12, S3C2410_GPE12_SPIMOSI0); //MOSI
  s3c2410_gpio_setpin(S3C2410_GPE12, 1);
  s3c2410_gpio_cfgpin(S3C2410_GPE11, S3C2410_GPE11_SPIMISO0); //MISO
  s3c2410_gpio_setpin(S3C2410_GPE11, 1);
  
  

• Interrupt Reauest (IRQ) pin Configaration

  //static void __init w5300e01_init(void)
  
  /* W5500 interrupt pin */
  s3c2410_gpio_cfgpin(S3C2410_GPG2, S3C2410_GPG2_EINT10); //GPG2 Interrupt
  s3c2410_gpio_setpin(S3C2410_GPG2, 1); //low active
  

• Reset pin configration

  //static void __init w5300e01_init(void)
  
  /* W5500 Reset pin */
  s3c2410_gpio_cfgpin(S3C2410_GPF6, S3C2410_GPF6_OUTP);
  s3c2410_gpio_setpin(S3C2410_GPF6, 1);
  

• Virtual Base address configration

  static struct map_desc w5300e01_iodesc[] __initdata = {
    { 0xf0000000, __phys_to_pfn(S3C2410_CS2), SZ_1M, MT_DEVICE },
    { 0xf8000000, __phys_to_pfn(S3C2410_CS3), SZ_1M, MT_DEVICE },
    { 0xe8000000, __phys_to_pfn(S3C2410_PA_SPI), SZ_1M, MT_DEVICE } 
  };
  
  

W5500 Linux Driver Porting

이부분은 Target MCU와 Target MCU의 SPI에 의존적인 부분으로 Target MCU와 SPI의 특성을 이해하고 설정하여야 한다.

• Enable PCLK into SPI block

  //dev.c
  void iinchip_spiclock_init(void)
  {
      ...
      reg = ioremap((unsigned long)rCLKCON, 4);
      *reg |= 0x40000;
      ...
  }
  

• Control: polling mode / SPI Clock enable / master select / CPOL =0 / CPHA =0 /etc…

  //spi.h
  (*(volatile unsigned char *)(_rSPCON0) = (0x18)) 
  

• baudrate: PCLK / 2 / ((SPPRE0) + 1)

  //spi.h
  (*(volatile unsigned char *)(_rSPPRE0) = (0x02));
  

• IRQ

  //module.c
  wiz_module_init(void)
  {
      ...
      gDrvInfo.irq  = IRQ_EINT10;
      ...
  }
  

• Chip Select

  //spi.h
  #define IINCHIP_CSon(Cs)                    (*_rGPFDAT) |= 0x2
  #define IINCHIP_CSoff(Cs)                   (*_rGPFDAT) &= 0xfffffffd
  

• Default MAC address
  W5500에 Default MAC address를 Write하는 부분이며, kernel에서 ifconfig를 이용하여 MAC Address를 변경할 수 도 있다.

  //module.c
  static unsigned char defmac[] = { 0x00, 0x08, 0xDC, 0x91, 0x97, 0x98 };
  
  static int __init
  wiz_module_init(void)
  {
      ...
      /* mac address */
      memcpy(gDrvInfo.macaddr, defmac, 6);
      ...
  }
  

• Socket buffer size 설정
  W5500에는 8개의 Socket이 존재하나, MACRAW type으로 W5500을 MAC/PHY로 사용할 것이기 때문에
  Socket 0번에만 TX/RX buffer를 각각 8KBytes로 설정한다. (MACRAW mode는 Socket 0번 사용가능하다.)

  //dev.cstatic unsigned char txsize[MAX_SOCK_NUM] = {
  8, 0, 0, 0, 0, 0, 0, 0
  };
  static unsigned char rxsize[MAX_SOCK_NUM] = {
  8, 0, 0, 0, 0, 0, 0, 0
  };
  
  void iinchip_sysinit(void)
  {
      ...
      for (i = 0 ; i < MAX_SOCK_NUM; i++) {
  
          /* Set Buffer Size */
          iinchip_outb(TX_BUF_SIZE_PTR(i), txsize[i]);
          iinchip_outb(RX_BUF_SIZE_PTR(i), rxsize[i]);
  
      ...
  }
  

• SPI READ / WRITE Functions
  Target MCU가 변경시 아래의 #define부분 들을 수정하여 SPI Read/Write를 구현할 수 있다.

  //spi.h
  #define SPI0_RxData()                   (*(volatile unsigned char *)(_rSPRDAT0)) //(ioread8(_rSPRDAT0))
  
  #define SPI0_TxData(Data)               (*(volatile unsigned char *)(_rSPTDAT0) = (Data)) //(iowrite8(Data, _rSPTDAT0
  #define SPI0_WaitForSend()              while(!((*(volatile unsigned char *)(_rSPSTA0)) & 0x01)) //while(!(ioread8(_rSPSTA0) & 0x01))
  
  #define SPI0_SendByte(Data)             SPI0_TxData(Data);SPI0_WaitForSend()
  #define SPI0_RecvBute()                 SPI0_RxData()
  
  

• Hardware Reset for W5500

  //dev.c
  void iinchip_hwreset(void)
  {
      s3c2410_gpio_setpin(S3C2410_GPF6, 0);
      mdelay(1);
      s3c2410_gpio_setpin(S3C2410_GPF6, 1);
      mdelay(2);
      mdelay(3000);// WIZ550IO Need for MCU which is embedded on Board.
  }
  
  

NEXT: Note4 – How to test the W5500 Linux driver