f1c100s tina pwm背光亮度调整

[ubuntu]

sys_config.fex

[lcd0]
lcd_used            = 1
...
lcd_pwm_used        = 1
lcd_pwm_ch          = 1
lcd_pwm_freq        = 50000
lcd_pwm_pol         = 0
lcd_pwm_max_limit   = 255

[disp]
disp_init_enable         = 1

...
lcd0_backlight           = 255
lcd1_backlight           = 255

lcd0_bright              = 255
lcd0_contrast            = 50
lcd0_saturation          = 57
lcd0_hue                 = 50

lcd1_bright              = 255
lcd1_contrast            = 50
lcd1_saturation          = 57
lcd1_hue                 = 50

[pwm1_para]
pwm_used            = 1
pwm_positive        = port:PE06<3><0><default><default>

用户层调整亮度：

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>

#define DISP_CMD_LCD_SET_BRIGHTNESS  0x102

int dispfd;

void main()
{

        unsigned long arg[3];
        unsigned int bl = 0;
        arg[0] = 0;//显示通道0
        arg[1] = bl;

        dispfd                 = open("/dev/disp", O_RDWR);

        if(dispfd <0)
        {
                printf("open disp error\n");
        }

        ioctl(dispfd, DISP_CMD_LCD_SET_BRIGHTNESS, (void*)arg);

        close(dispfd);

        printf("end\n");
}

[ubuntu]

https://www.cnblogs.com/dakewei/p/13323567.html

或者用pwm直接调整亮度：

echo 1 > /sys/class/pwm/pwmchip0/export

echo 10000 > /sys/class/pwm/pwmchip0/pwm1/period

echo 5000 > /sys/class/pwm/pwmchip0/pwm1/duty_cycle

echo 'normal' > /sys/class/pwm/pwmchip0/pwm1/polarity

echo 1 > /sys/class/pwm/pwmchip0/pwm1/enable