adv748x_read
int adv748x_read(struct adv748x_state *state, u8 addr, u8 reg);
#define io_read(s, r) adv748x_read(s, ADV748X_PAGE_IO, r)
#define hdmi_read(s, r) adv748x_read(s, ADV748X_PAGE_HDMI, r)
#define repeater_read(s, r) adv748x_read(s, ADV748X_PAGE_REPEATER, r)
#define sdp_read(s, r) adv748x_read(s, ADV748X_PAGE_SDP, r)
#define cp_read(s, r) adv748x_read(s, ADV748X_PAGE_CP, r)
#define tx_read(t, r) adv748x_read(t->state, t->page, r)