读写SPI FLASH--驱动部分（9） FLASH

yuyang911220

static int write_byte(uint32_t addr, uint8_t byte)
{
    uint32_t word, var, val;
   
    var = byte;
    writel(var, (void *)(spi_char.mem_virt+SPI_DATA0));
    writel(addr, (void*)(spi_char.mem_virt+SPI_ADDR));
    word = readw((void *)(spi_char.mem_virt+SPI_CTRL));
    word |= SPI_CTRL_SCGO; /* set cycle */
    word |= SPI_CTRL_ACS; /* Enable Atomic Cycle Sequence */
    word &= ~SPI_CTRL_SPOP;
    word &= ~SPI_CTRL_COP;     
    word = word | SPI_CTRL_OPMENU_WR<<SPI_CTRL_COP_SHIFT; /* write */
    word &= ~SPI_CTRL_DBC;     
    word = word | 0x00<<SPI_CTRL_DBC_SHIFT; /* write count=1 */
    word |= SPI_CTRL_DC;
     
     /* check the status */
     val = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     while(val & SPI_STATUS_SCIP)
     {
            val = readw((void *)(spi_char.mem_virt+SPI_STATUS));/* check the status */
     }
         
     writew(word, (void *)(spi_char.mem_virt+SPI_CTRL));
         
     /* check the status */
     val = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     while(val & SPI_STATUS_SCIP)
     {
        val = readw((void *)(spi_char.mem_virt+SPI_STATUS));/* check the status */
     }
     
     word = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     word |= SPI_STATUS_CDS; /* clear Cycle Done Status flag */
     word |= SPI_STATUS_BAS;  /* clear blocked flag */
     writew(word, (void *)(spi_char.mem_virt+SPI_STATUS));
     
    return (1);
}


static uint8_t read_byte(uint32_t addr)
{
    uint32_t word, var, val;
    uint8_t ret;
   
     word = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     word |= SPI_STATUS_CDS; /* clear Cycle Done Status flag */
     word |= SPI_STATUS_BAS;  /* clear blocked flag */
     writew(word, (void *)(spi_char.mem_virt+SPI_STATUS));
    writel(addr, (void*)(spi_char.mem_virt+SPI_ADDR));
    word = readw((void *)(spi_char.mem_virt+SPI_CTRL));
    word |= SPI_CTRL_SCGO; /* set cycle */
    word &= ~SPI_CTRL_ACS; /* Diable Atomic Cycle Sequence */
    //word &= ~SPI_CTRL_SPOP;
    word &= ~SPI_CTRL_COP;     
    word = word | SPI_CTRL_OPMENU_RD<<SPI_CTRL_COP_SHIFT; /* read */
    word &= ~SPI_CTRL_DBC;     
    word = word | 0x00<<SPI_CTRL_DBC_SHIFT; /* read count=1 */
    word |= SPI_CTRL_DC;
     
     /* check the status */
      val = readw((void *)(spi_char.mem_virt+SPI_STATUS));/* check the status */
     while(val & SPI_STATUS_SCIP)
     {
          val = readw((void *)(spi_char.mem_virt+SPI_STATUS));/* check the status */
     }
         
     writew(word, (void *)(spi_char.mem_virt+SPI_CTRL));
     SPI_DBG("read_byte: ctrl=%08x/n", word);
         
     /* check the status */
     val = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     while(val & SPI_STATUS_SCIP)
     {
        val = readw((void *)(spi_char.mem_virt+SPI_STATUS));/* check the status */
     }
     var = readl((void *)(spi_char.mem_virt+SPI_DATA0));
     SPI_DBG("read_byte: data=%08x", var);
     ret = var & 0xFF;
   
     word = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     word |= SPI_STATUS_CDS; /* clear Cycle Done Status flag */
     word |= SPI_STATUS_BAS;  /* clear blocked flag */
     writew(word, (void *)(spi_char.mem_virt+SPI_STATUS));
     
    return (ret);
}

static int erase_chip(void)
{
     uint32_t word, var, val;
     
    /* disable flash protection */
    if(is_flash_protection())
    {
        if(!disable_flash_protection())
        {
            SPI_ERR("can't disable flash protection/n");
            return (0);
        }
        SPI_DBG("erase_chip is_flash_protection/n") ;
    }
   
    word = readw((void *)(spi_char.mem_virt+SPI_CTRL));
    word |= SPI_CTRL_SCGO; /* set cycle */
    word |= SPI_CTRL_ACS; /* Enable Atomic Cycle Sequence */
    word &= ~SPI_CTRL_SPOP;
    word &= ~SPI_CTRL_COP;     
    word = word | SPI_CTRL_OPMENU_CHIPERASE<<SPI_CTRL_COP_SHIFT; /* write */
    word &= ~SPI_CTRL_DBC;     
    word = word | 0x00<<SPI_CTRL_DBC_SHIFT; /* write count=1 */
    word &= ~SPI_CTRL_DC;
     
     /* check the status */
     val = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     while(val & SPI_STATUS_SCIP)
     {
            val = readw((void *)(spi_char.mem_virt+SPI_STATUS));/* check the status */
     }
         
     writew(word, (void *)(spi_char.mem_virt+SPI_CTRL));
         
     /* check the status */
     val = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     while(val & SPI_STATUS_SCIP)
     {
        val = readw((void *)(spi_char.mem_virt+SPI_STATUS));/* check the status */
     }
     
     word = readw((void *)(spi_char.mem_virt+SPI_STATUS));
     word |= SPI_STATUS_CDS; /* clear Cycle Done Status flag */
     word |= SPI_STATUS_BAS;  /* clear blocked flag */
     writew(word, (void *)(spi_char.mem_virt+SPI_STATUS));
     SPI_DBG("erase_chip() end/n");
     
     return (1);
}