GPIO is not enough on WP7607

mangOH Yellow
1

Because GPIO is not enough on WP7607 , can I use pcm , uart1 or wake_on_wwan pin as GPIO(is it support multi function? ) ?

2

You can use ioctl to control 8 wire uart

You can also modify the yocto source to make those uart pin to be gpio

1 Like
3

Hi jyijyi,

I tried to use ioctl() call to control uart1 RTS pin (and check pin status on CN601.15) , but did not see the status change

#include <sys/ioctl.h> //ioctl() call defenitions
#include <fcntl.h>

main()
{
   int fd;
   fd = open("/dev/ttyHS0",O_RDWR | O_NOCTTY );//Open Serial Port
   int RTS_flag;
   RTS_flag = TIOCM_RTS;
   while(1){
    printf("RTS High\n");
    ioctl(fd,TIOCMBIS,&RTS_flag);//Set RTS pin
    sleep 2
    //getchar();
    printf("RTS Low\n");
    ioctl(fd,TIOCMBIC,&RTS_flag);//Clear RTS pin       
   }

   close(fd);
}

So I use sysfs way to do it DCD control (should it be GPIO24?) , But it seems that there is no state change

echo 24 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio24/direction
echo 1 > /sys/class/gpio/gpio24/value

Do I want to modify the kernel or is there any error in setting? (on mangOH yellow)

4

You can see here on how to control the cts pin

Also you need to recompile yocto image to control dcd dtr dsr as gpio

5

Hi jyijyi,

Thank you for kind explanation, but I use ioctl to execute on mangoh yellow and still cannot make RTS, DCD, DTR, CTS… and other pin output status change

   int fd;
   fd = open("/dev/ttyHS0",O_RDWR | O_NOCTTY );//Open Serial Port
   
   int RTS_flag = TIOCM_RTS;
   int DCD_flag = TIOCM_CD;
   int DTR_flag = TIOCM_DTR;
   int CTS_flag = TIOCM_CTS;
   while(1){
    printf("RTS High\n");
    ioctl(fd,TIOCMBIS,&RTS_flag);//Set RTS pin
    sleep(1);
    ioctl(fd,TIOCMBIC,&RTS_flag);
    ioctl(fd, TIOCMSET, &DCD_flag);
    sleep(1);
    ioctl(fd,TIOCMBIC,&DCD_flag);
    ioctl(fd, TIOCMSET, &DTR_flag);
    sleep(1);
    ioctl(fd,TIOCMBIC,&DTR_flag);
    ioctl(fd, TIOCMSET, &CTS_flag);
    sleep(1);
    ioctl(fd,TIOCMBIC,&CTS_flag);

(The FW version on my platform)

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image942Ă—305 10.6 KB

So I tried to modify gpiolib-sysfs so that flow-control can be changed by sysfs , and I found that there is no “ext_gpio_map ext_gpio_wp” in my gpiolib-sysfs.c , the yocto sourcecode I used is “Legato-Dist-Source-mdm9x28-SWI9X07Y_02.37.07.00.tar.bz2” (R16 firmware).

Where can I download the appropriate FW version for compilation?

6

Is that you must use R16?
I remember i used R13 at that time.

Your code is not changing the pin status
This is the code to change CTS pin

     int arg;
	 if (ioctl(fd1, TIOCMGET, &arg) == -1)
	 {
	 	LE_DEBUG("ERROR: %s", strerror(errno));
	 }

	 if (level)
		  arg |= TIOCM_RTS;
	   else
	   	  arg &= ~TIOCM_RTS;

	  if (ioctl(fd1, TIOCMSET, &arg) == -1) {
	    		LE_DEBUG("ERROR: %s", strerror(errno));
	      }
7

Hi jyijyi,

Thanks for your quick reply

I tried to rebuild the source code of Yocto and change gpiolib-sysfs.c
After generating the .cwe file, combine cwe into custom-firmware image and -reflash

image
image1688Ă—550 113 KB

Some error occurred when we type
echo 17> /sys/class/gpio/export
image

I checked the kernel build date and found that the build date has not been updated

image
image871Ă—288 41.2 KB

Is my burning method wrong? (Or choose the wrong file)

8

You can directly update the yocto_wp76xx.cwe

9

Thanks your comment
I’d re-flash mangoh with yocto_wp76xx.4k.cwe only, but the test result is still the same, the build date and gpio sysfs have not been updated

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image1007Ă—62 10 KB

test result:

image
image869Ă—123 24.2 KB

10

didn’t Apr19 22:05:25 already updated?

How do you change for gpiolib-sysfs.c ?

You can use my yocto image for WP76 on R13:
root@swi-mdm9x28-wp:~# echo 101 > /sys/class/gpio/export
root@swi-mdm9x28-wp:~# echo 102 > /sys/class/gpio/export
root@swi-mdm9x28-wp:~# microcom /dev/ttyAT
ati8
Legato Ver: 20.04.0_96205776d64ef766ba918ebe5586c885_modified
Yocto Ver: SWI9X07Y_02.28.03.05 2020-03-09_02:35:57
OS Ver: Linux version 3.18.131 (oe-user@oe-host) (gcc version 7.3.0 (GCC) ) #1 PREEMPT Wed Feb 26 04:17:04 UTC 2020
LK Ver: SWI9X07Y_02.28.03.05
RootFS Ver: SWI9X07Y_02.28.03.05 2020-03-09_02:35:57
UserFS Ver: unknown
MCU Ver: 002.011

OK

11

Thanks

It looks like an incorrect flash command caused no update

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image1094Ă—272 40 KB