How to set gpio0_4 as chipselect for spi2

Hi,
I really don't know how to configure the SPI and gpio,could you give me some suggestions?
Thank you very much.
Bob

Bob,

Ensure gpio0_4 pin is mux correctly. I can also provide you the below pointers:

processors.wiki.ti.com/.../TI81XX_PSP_McSPI_Driver_User_Guide
processors.wiki.ti.com/.../OMAP-L1x
processors.wiki.ti.com/.../MontaVista_Linux_SPI_Driver

e2e.ti.com/.../299820
e2e.ti.com/.../368940

BR
Pavel

Hi Pavel,

I add controller_data in struct spi_board_info __initdata ti8148_spi_slave_info[],but the kernel is panic when read spi.

 {
  .modalias = "spidev",
  .irq  = -1,
  .max_speed_hz = 500000,
  .bus_num = 2,
  .chip_select = 0,
  .mode = SPI_MODE_3,
  .controller_data    =  (void *) 4, // gpio0_4
 },

Do you tell me how to modify the code ?

Thank you

Bob

Bob,

At which physical pin you export the gpio0_4 signal? And do you connect this pin to the CS external chip? Are you driving gpio0_4 to low to select this external chip?

Regards,
Pavel

Hi Pavel,

At which physical pin you export the gpio0_4 signal?

The physical pin is Y5.

And do you connect this pin to the CS external chip?

Yes

Are you driving gpio0_4 to low to select this external chip?

Yes

I use dvrrdk_04.01.00.02 and our board is based on dm8148.

I think I don't modify the code correctly,that is ,maybe I don't know how to add the gpio as chipselect in the code.

Need your more help.Thank you.

Bob

Bob,

I do not have ready made patch for your custom board. You can have a look in the below resources, they might be in help:

bob lee said:

I use dvrrdk_04.01.00.02

Check the below post regarding DVR RDK support:

Regards,
Pavel

Hi Pavel,

I just find the c file spi_gpio.c and spi_bitbang.c in the linux source code.

So I want to know whether the gpio/cs are related to the spi_gpio.c and spi_bitbang.c or not.

Thank you.

Bob

Hi Pavel,

And I also find there is no chip_sel member int the struct davinci_spi_platform_data in out source code .

Here is the struct in my kernel.

struct davinci_spi_platform_data {
 u8 version;
 u8 num_chipselect;
 u8 wdelay;
 u8 odd_parity;
 u8 parity_enable;
 u8 wait_enable;
 u8 timer_disable;
 u8 clk_internal;
 u8 cs_hold;
 u8 intr_level;
 u8 poll_mode;
 u8 use_dma;
 u8 c2tdelay;
 u8 t2cdelay;
};

Bob

Hi Pavel,

From the post,I can see chip_sel  in devices-da8xx.c.

struct davinci_spi_platform_data da8xx_spi_pdata[] = {
 [0] = {
  .version = SPI_VERSION_2,
  .intr_line = 1,
  .dma_event_q = EVENTQ_0,
                .num_chipselect = ARRAY_SIZE(csi_spi0_chip_selects),
                .chip_sel       = (void*)csi_spi0_chip_selects,
 },
 [1] = {
  .version = SPI_VERSION_2,
  .intr_line = 1,
  .dma_event_q = EVENTQ_0,
                .num_chipselect = ARRAY_SIZE(csi_spi1_chip_selects),
                .chip_sel       = (void*)csi_spi1_chip_selects,
 },
};

BR

Bob