Driving Drv8823 : interface with Dm8127

Hi Akash,

Your post is being moved to the DaVinci forum. This is really a question about the firmware.

In general, the motor driver forum supports the hardware and EVMs.

Hi,

i want to drive my stepper motor with Drv8823 driver chip, which is directly connected to my Dm8127 board via spi interface.

i've built-in support of spi generic driver module in kernel.

and i applied changes in board specific file with spi_board_info structure..
        {
                .modalias       = "spidev",
                .irq            = -1,
                .max_speed_hz   = 100000,
                .bus_num        = 1,
                .chip_select    = 1,
                .mode = SPI_MODE_3,
        },

i've created node in /dev by mknod -m 666 /dev/spidev1.1 c 153 3.
when i use spidev_test file to send data to driver chip...
i got , "can't open device: No such device or address, Aborted".

what's wrong with this. is there any Linux driver available for drv8823?

regards,
Akash Gajjar

Moving to the appropriate forum

Regards,
Gigi Joseph.

Hi Akash,

Akash Gajjar said:

is there any Linux driver available for drv8823?

I made a search in the DM8127 linux kernel code base, but I can not find DRV8823 (DRV8x) driver.

And I think this is the root cause for the issue.

For example, DM814x EVM has SPI flash:

board-ti8148evm.c

struct spi_board_info __initdata ti8148_spi_slave_info[] = {
    {
        .modalias    = "m25p80",
        .platform_data    = &ti8148_spi_flash,
        .irq        = -1,
        .max_speed_hz    = 75000000,
        .bus_num    = 1,
        .chip_select    = 0,
    },

m25p80 driver is located at:

drivers/mtd/devices/m25p80.c

Another example is DM814x IPNC board, it has audio codec attached to SPI:

board-ti8148ipnc.c

struct spi_board_info __initdata ti8148_spi_slave_info[] = {
    {
        .modalias    = "tlv320aic26-codec",
        .irq        = -1,
        .max_speed_hz    = 100000,
        .bus_num    = 1,
        .chip_select    = 0,
        .mode = SPI_MODE_1,
    },
};

tvl320aic26 codec driver is located at:

sound/soc/codecs/tvl320aic26.c

And there is no drv8823.c file in the DM81xx linux kernel.

See also the below wiki page:

BR
Pavel

Hi Akash,

This thread will be merged with your original post.

Akash,

Regarding spidev usage, refer to the below links:

processors.wiki.ti.com/.../RF4CE,_simple_linux_target_application
processors.wiki.ti.com/.../CC3000_Module_with_AM335x_Using_Linux
processors.wiki.ti.com/.../Linux_Core_SPI_User's_Guide

e2e.ti.com/.../354202
e2e.ti.com/.../314145
e2e.ti.com/.../895080
e2e.ti.com/.../776116
e2e.ti.com/.../382636

BR
Pavel

Hi,

now there is littile bit progress on my board.
i am using ioctl to transfer spi packets to the driver chip via spidev driver on spi bus 1.
SPI[1]_SCS[0], SPI[1]_SCLK, SPI[1]_D[1], SPI[1]_D[0] which is muxed with GP1[16], GP1[17], GP1[18], and GP1[26] respectively.
i am doing muxing in uboot code to spi instead of gpio.

i am varifying this muxing using devmem2 command on my board.
but it shows that it is muxed as a gpio instead of spi.

i've also checked in kernel code as there is possibility to undone this muxing.
but didn't found any function..

so what is reason for this.

regards,
Akash