DM365 DM368 SPI Interface

Yes, you are correct that one cannot read/write from/to two data flashes to the same SPI interface due to the CS1 pin is muxed with the SOMI at every SPI module.

You can use one read/write device and one write-only device on the same SPI but it requires the pin mux reconfigured between when accessing between the two devices.

I would recommend to use two SPI's to interface two flashes.

Thanks and regards,

Tai  

Another alternative is to use a GPIO for the second chip select.

The DM365 2.6.18 kernel SPI driver supports passing in the desired GPIO in the platform data:

static u8 dm365_spi1_chipselects[] = {
     DAVINCI_SPI_INTERN_CS, // Chip select 0 - internal
     32,                    // Chip select 1 - use GIO32
};

static struct davinci_spi_platform_data dm365_spi_pdata = {
    .version = DAVINCI_SPI_VERSION_1,
    .num_chipselect = 2,
    .chip_sel = &dm365_spi1_chipselects[0],
    .clk_name = "SPI1CLK",
};

That is a very good idea - if all other 4 SPI's are used.

Thanks for sharing it.

-Tai Nguyen