读写SPI FLASH--驱动部分（10） protection, flash, return, FLASH

yuyang911220

static int erase_4K_sector(unsigned int idx)
{
    uint32_t addr;
    uint32_t word, var, val;
   
    if(((idx+1)<< SPI_FLASH_SECTOR_BIT) > SPI_FLASH_SIZE)
    {
        return (1);
    }
   
     /* disable flash protection */
    if(is_flash_protection())
    {
        if(!disable_flash_protection())
        {
            SPI_ERR("can't disable flash protection/n");
            return (0);
        }
    }
   
    addr = idx<<SPI_FLASH_SECTOR_BIT;
    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_4KERASE<<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("spi_4kerase end/n");
     
    return (1);
}