STV090x_TSTTNR4
{ STV090x_TSTTNR4, 0x21 },
reg = stv090x_read_reg(state, STV090x_TSTTNR4);
if (stv090x_write_reg(state, STV090x_TSTTNR4, reg) < 0)
reg = stv090x_read_reg(state, STV090x_TSTTNR4);
if (stv090x_write_reg(state, STV090x_TSTTNR4, reg) < 0)