TDA4VM: How to use chip select for SPIDEV in device tree

Hi,  Keerthy

SPI3 device node with CS1 appears.

spidev 3.0 works fine, but spidev 3.1 doesn't work, because I do not capture any physical signal from spidev3.1

1. DT Modify as below:

	main_spi3: spi@2130000 {
		compatible = "ti,am654-mcspi","ti,omap4-mcspi";
		reg = <0x0 0x2130000 0x0 0x400>;
		interrupts = <GIC_SPI 187 IRQ_TYPE_LEVEL_HIGH>;
		clocks = <&k3_clks 269 1>;
		power-domains = <&k3_pds 269 TI_SCI_PD_EXCLUSIVE>;
		ti,spi-num-cs = <2>;
		#address-cells = <1>;
		#size-cells = <0>;
	};

2. check spidev node, it's fine

root@j7-evm:~# ls /dev/ | grep spidev
spidev3.0
spidev3.1

3. write data to spi 3.0 and physical signal capture

root@j7-evm:~# ./spidev_test -v -D /dev/spidev3.0 -p "HELLOWORLD"
spi mode: 0x0
bits per word: 8
max speed: 500000 Hz (500 KHz)
TX | 48 45 4C 4C 4F 57 4F 52 4C 44 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __  |HELLOWORLD|
RX | 00 00 00 00 00 00 00 00 00 00 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __  |..........|

if I .set  /spidev_test -v -D /dev/spidev3.1 -p "HELLOWORLD", No signal out.

Do I miss something?

Many Thanks

Gibbs

add more DT information

&main_spi3 {
    pinctrl-names = "default";
    pinctrl-0 = <&main_spi3_pins_default>;
    status="okay";
	/*status = "disabled";*/

    spidev@0 {
       spi-max-frequency = <24000000>;
       reg = <0>;
       compatible = "linux,spidev";

	   //smi130_acc@0{
  	 	//		spi-max-frequency = <500000>;					
  		//		compatible = "smi130_acc";
  		//		reg = <0>;
  				/*interrupt-parent = <&msmgpio>;
  				interrupts = <115 0>; 
  				smi130_acc,gpio_irq = <&msmgpio 115 0>;*/			
  		//};

  		//smi130_gyro@1{
  		//		spi-max-frequency = <500000>;					
  		//		compatible = "smi130_gyro";
  		//		reg = <1>;
  				/*interrupt-parent = <&msmgpio>;
  				interrupts = <13 0>; 
  				smi130_gyro,gpio_irq = <&msmgpio 13 0>;*/
  		//};
	};

	spidev@1 {
       spi-max-frequency = <24000000>;
       reg = <1>;
       compatible = "linux,spidev";

	};

};

Today update,

I wrote a simple SPI read program to test  "/dev/spidev3.1"

cs1 --> no action

miso -> have signal, correct 

mosi -> have signal, corrett

clk -> yes!

code as below:

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

static uint8_t  mode;
static uint8_t  bits = 8;
static uint32_t speed = 2*1000;         //32*100*1000; //500000;
static uint16_t delay = 0;


#if 0
//read operating
static int transfer_r(int fd,unsigned short addr)
{
	int ret;
    unsigned char  cmd[2];
    unsigned char  databuffer[4];
    unsigned char  mydatabuffer[2];
	struct spi_ioc_transfer	xfer[2];
	
    
    cmd[0] = addr & 0x00ff; 
    cmd[1] = 0x80 | (addr >> 8); 
    memset(xfer,0,2*sizeof(struct spi_ioc_transfer));
    memset(databuffer,0x00,2);
    xfer[0].tx_buf          = (unsigned long)cmd;
    xfer[0].rx_buf          = NULL;
    xfer[0].len             = 2;
    xfer[0].delay_usecs     = delay;
    xfer[0].bits_per_word   = bits;	
    xfer[0].speed_hz        = speed;
        
    
    
    xfer[1].rx_buf          = (unsigned long)databuffer;
    xfer[1].tx_buf          = NULL;
    xfer[1].len             = 4;
    xfer[1].delay_usecs     = delay;
    xfer[1].bits_per_word   = bits;	
    xfer[1].speed_hz        = speed;
    


    ret = ioctl(fd, SPI_IOC_MESSAGE(2), &xfer);
	if (ret == -1 )
	    printf("can't transfer");

	printf("databuffer[0]=0x%x\n",databuffer[0]);
	printf("databuffer[1]=0x%x\n",databuffer[1]);
	printf("databuffer[2]=0x%x\n",databuffer[2]);
	printf("databuffer[3]=0x%x\n",databuffer[3]);

	return ((databuffer[1] << 8) + databuffer[0]);
}
#else
static int transfer_r(int fd,unsigned short addr)
{
	int ret;
    unsigned char  cmd[2];
    unsigned char  databuffer[4];
    unsigned char  mydatabuffer[2];
	struct spi_ioc_transfer	xfer[2];
    
    cmd[0] = addr & 0x00ff; 
    cmd[1] = 0x80 | (addr >> 8); 
    memset(xfer,0,2*sizeof(struct spi_ioc_transfer));
    memset(databuffer,0x00,2);
    xfer[0].tx_buf          = (unsigned long)cmd;
    xfer[0].rx_buf      = (unsigned long)databuffer;
    xfer[0].len             = 2;
    xfer[0].delay_usecs     = delay;
    xfer[0].bits_per_word   = bits;	
    xfer[0].speed_hz        = speed;
        

	ret = ioctl(fd, SPI_IOC_MESSAGE(1), &xfer);
	if (ret == -1 )
	    printf("can't transfer");

	printf("databuffer[0]=0x%x\n",databuffer[0]);
	printf("databuffer[1]=0x%x\n",databuffer[1]);
	printf("databuffer[2]=0x%x\n",databuffer[2]);
	printf("databuffer[3]=0x%x\n",databuffer[3]);

	return ((databuffer[1] << 8) + databuffer[0]);
	
}
#endif

int smi130_read(char *s, unsigned short addr){
	
	int len, status, fd;
	
	fd = open(s, O_RDWR);
	
	if (fd < 0) {
		perror("open");
		return 1;
	}else {
		printf("Open SPI Port %s\n", s);
	}
	
	status = ioctl(fd, SPI_IOC_WR_MODE, &mode);
	if (status == -1)
		printf("can't set spi mode");

	status = ioctl(fd, SPI_IOC_RD_MODE, &mode);
	if (status == -1)
		printf("can't get spi mode");

	status = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
	if (status == -1)
		printf("can't set bits per word");

	status = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
	if (status == -1)
		printf("can't get bits per word");

	status = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
	if (status == -1)
		printf("can't set max speed hz");

	status = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
	if (status == -1)
		printf("can't get max speed hz");
	
	
	printf("spi mode: %d\n", mode);
	printf("bits per word: %d\n", bits);
	printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
	
	status = transfer_r(fd, addr);
	close(fd);
	
	return status;
    
}



int main(int argc, char **argv)
{
	char *name;
	int ret;
	//struct spi_ioc_transfer xfer[2];
	//unsigned char buf[32], *bp;
	
	name = argv[1];
	
	while(1){
		ret = smi130_read(name, 0x00);
		printf("ret = %d\n", ret);
		usleep(300);
		
		ret = smi130_read(name, 0x40);
		printf("ret = %d\n", ret);
		usleep(300);
		
	    ret = smi130_read(name, 0x60);
		printf("ret = %d\n", ret);
		usleep(300);
	}
	



	return 0;
}

the problem is why chip select 1 do not work?

Any Comment?

Many Thanks

Keerthy ,

You are right! 

Our HW make a mistake,  CS1 & MOSI are short.

The scope shows correct work after HW re-work

Many Thanks

Gibbs