I wan't to implement a display contrast adjustment machanism in linear mode, but I don't know how to do it.
according to Gamma correction on i.MX6 , following steps can do gamma correction:
1 - Declare a variable as mxcfb_gamma:
struct mxcfb_gamma fb_gamma;
2 - Enable the gama correction:
fb_gamma.enable = 1;
3 - Set the constk and slopek values, where i = 0 to 15 and x and y are respectively the new constk and slopek constant values:
fb_gamma.constk[i] = x;
fb_gamma.slopek[i] = y;
4 - Open the framebuffer device and call MXCFB_SET_GAMMA:
fd_fb = open("/dev/fb0", O_RDWR, 0)
ioctl(fd_fb, MXCFB_SET_GAMMA, &fb_gamma)
how do I choose the constk & slopek values to insure the contrast vary in linear mode?
