【轉】RK3288 GPIO 輸出問題

cat /sys/kernel/debug/gpio

cat /proc/bus/input/devices 

 

#define GPIO_BANK0              (0 << RK_GPIO_BANK_OFFSET)                                                                                                             

#define GPIO_BANK1              (1 << RK_GPIO_BANK_OFFSET)
#define GPIO_BANK2              (2 << RK_GPIO_BANK_OFFSET)
#define GPIO_BANK3              (3 << RK_GPIO_BANK_OFFSET)
#define GPIO_BANK4              (4 << RK_GPIO_BANK_OFFSET)
#define GPIO_BANK5              (5 << RK_GPIO_BANK_OFFSET)
#define GPIO_BANK6              (6 << RK_GPIO_BANK_OFFSET)
#define GPIO_BANK7              (7 << RK_GPIO_BANK_OFFSET)
#define GPIO_BANK8              (8 << RK_GPIO_BANK_OFFSET)

#define RK_GPIO_BANK_OFFSET   8

#define GPIO_A0                 0
#define GPIO_A1                 1
#define GPIO_A2                 2
#define GPIO_A3                 3
#define GPIO_A4                 4
#define GPIO_A5                 5
#define GPIO_A6                 6
#define GPIO_A7                 7
#define GPIO_B0                 8
#define GPIO_B1                 9
#define GPIO_B2                 10
#define GPIO_B3                 11
#define GPIO_B4                 12
#define GPIO_B5                 13
#define GPIO_B6                 14
#define GPIO_B7                 15
#define GPIO_C0                 16
#define GPIO_C1                 17
#define GPIO_C2                 18
#define GPIO_C3                 19
#define GPIO_C4                 20
#define GPIO_C5                 21
#define GPIO_C6                 22
#define GPIO_C7                 23
#define GPIO_D0                 24
#define GPIO_D1                 25
#define GPIO_D2                 26
#define GPIO_D3                 27
#define GPIO_D4                 28
#define GPIO_D5                 29
#define GPIO_D6                 30
#define GPIO_D7                 31

如gpio7 GPIO_B4就是(7 << RK_GPIO_BANK_OFFSET) | GPIO_D2
簡單點的寫法就是7x32+12=236

GPIO7_B4=236   //M180_V3 << SPICLLK

GPIO7_B5=237   //M180_V3 << SPICSN



shell  測試GPIO輸出驅動

echo 236 > /sys/class/gpio/export             //打開指定GPIO

echo out > /sys/class/gpio/gpio236/direction  //修改爲輸出

echo 1 >/sys/class/gpio/gpio236/value        //寫入輸出值  0 或者1



//poll示例：


memset((void *)xfds, 0, sizeof(xfds));
xfds[0].fd = fd;
xfds[0].events = POLLPRI;
ret = poll(xfds, 1, -1);
if(ret <= 0)
ERREXIT("poll value");
if(xfds[0].revents & POLLPRI)
{
/* get value */
ret = lseek(fd, 0, SEEK_SET);
if(ret < 0)
ERREXIT("lseek value");
ret = read(fd, buf, 2);
buf[1] = '\0';
printf("read ret = %d, value = %s\n", ret, buf);
if(ret != 2)
ERREXIT("read value");
}
//select示例：
FD_ZERO(&exceptfds);
FD_SET(fd, &exceptfds);
ret = select(fd+1,NULL,NULL,&exceptfds,NULL);
if(ret < 0)
ERREXIT("select value");
//else if(ret > 0)
if(ret > 0)
{
/* get value */
ret = lseek(fd, 0, SEEK_SET);
if(ret < 0)
ERREXIT("lseek value");
ret = read(fd, buf, 2);
buf[1] = '\0';
printf("read ret = %d, value = %x\n", ret, buf[0]);
if(ret != 2)
ERREXIT("read value");
}
//RK3288  GPIO 輸出驅動電流能力有限，請知悉！！！max_current  <=100MA

轉自：RK3288 GPIO 輸出問題