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Topic: SPI based radio interface with AR9331

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Post #1
lshah21
18 Sep 2014, 12:11

Hi all,

I would like to connect SPI based RF radio with AR9331.

I have gone through data sheet for AR9331 and it shows it has three different chip select for SPI.

The SPI_CS0 is used for SPI flash memory. I would like to use SPI_CS1 for interfacing my radio.

I have tried to disable the SPI_CS0 and try to use SPI_CS1, but i was not able to achieve this with the same.

I have try to read and write SPI register with different configuration but not able to achieve the same.

Regards,
Lalit Shah

(Last edited by lshah21 on 18 Sep 2014, 12:12)

Post #2
Deoptim
18 Sep 2014, 22:03

For example, profile for device:

...
...
static struct ath79_spi_controller_data device_spi0_cdata = {
    .cs_type = ATH79_SPI_CS_TYPE_INTERNAL,
    .cs_line = 0,
    .is_flash = true,
};

static struct ath79_spi_controller_data device_spi1_cdata = {
    .cs_type = ATH79_SPI_CS_TYPE_INTERNAL,
    .cs_line = 1,
};

static struct spi_board_info device_spi_info[] = {
    {
        .bus_num    = 0,
        .chip_select    = 0,
        .max_speed_hz    = 25000000,
        .modalias    = "m25p80",
        .platform_data  = &device_spi_flash_data,
        .controller_data = &device_spi0_cdata
    }, {
        .bus_num    = 0,
        .chip_select    = 1,
        .max_speed_hz    = 25000000,
        .modalias    = "spidev",
        .platform_data  = &device_spi_flash_data,
        .controller_data = &device_spi1_cdata
    }
};

static struct ath79_spi_platform_data device_spi_data __initdata = {
            .bus_num = 0,
            .num_chipselect = 2,
    };

...
...

spi_register_board_info(device_spi_info,
            ARRAY_SIZE(device_spi_info));
...
...

(Last edited by Deoptim on 18 Sep 2014, 22:05)

Post #3
lshah21
19 Sep 2014, 08:03

Hi,

I have added two SPI interface (SPI Chip Select 0 and 1) based on above code in my plateform.c file for AR9331 Board.

Then, I have compiled linux kernel image and flashed it into my AR9331 Board.

But, I haven't found any entries of both SPI devices into /dev as well as /sys/class directory. Also, I couldn't found any debug message regarding SPI devices in bootup message of kernel.

Do you have any idea about this issue?

Regards,
Lalit Shah

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