ST7571_PAGE_HEIGHT
ST7571_SET_PAGE(y / ST7571_PAGE_HEIGHT),
u32 npixels = st7571->ncols * round_up(st7571->nlines, ST7571_PAGE_HEIGHT) * st7571->bpp;
rect->y1 = round_down(rect->y1, ST7571_PAGE_HEIGHT);
rect->y2 = min_t(unsigned int, round_up(rect->y2, ST7571_PAGE_HEIGHT), st7571->nlines);
for (int y = rect->y1; y < rect->y2; y += ST7571_PAGE_HEIGHT) {
rect->y1 = round_down(rect->y1, ST7571_PAGE_HEIGHT);
rect->y2 = min_t(unsigned int, round_up(rect->y2, ST7571_PAGE_HEIGHT), st7571->nlines);
for (int y = rect->y1; y < rect->y2; y += ST7571_PAGE_HEIGHT) {