'struct timing_generator_funcs' are not modified in these drivers.
Constifying these structures moves some data to a read-only section, so
increases overall security, especially when the structure holds some
function pointers.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
        REG_GET(OTG_DRR_CONTROL, OTG_V_TOTAL_LAST_USED_BY_DRR, refresh_rate);
 }
 
-static struct timing_generator_funcs dcn20_tg_funcs = {
+static const struct timing_generator_funcs dcn20_tg_funcs = {
                .validate_timing = optc1_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,
 
        *num_of_src_opp = 1;
 }
 
-static struct timing_generator_funcs dcn201_tg_funcs = {
+static const struct timing_generator_funcs dcn201_tg_funcs = {
                .validate_timing = optc201_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,
 
        optc1_clear_optc_underflow(optc);
 }
 
-static struct timing_generator_funcs dcn30_tg_funcs = {
+static const struct timing_generator_funcs dcn30_tg_funcs = {
                .validate_timing = optc1_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,
 
                        OTG_TRIGA_CLEAR, 1);
 }
 
-static struct timing_generator_funcs dcn30_tg_funcs = {
+static const struct timing_generator_funcs dcn30_tg_funcs = {
                .validate_timing = optc1_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,
 
        s->otg_double_buffer_control = REG_READ(OTG_DOUBLE_BUFFER_CONTROL);
 }
 
-static struct timing_generator_funcs dcn31_tg_funcs = {
+static const struct timing_generator_funcs dcn31_tg_funcs = {
                .validate_timing = optc1_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,
 
 }
 
 
-static struct timing_generator_funcs dcn314_tg_funcs = {
+static const struct timing_generator_funcs dcn314_tg_funcs = {
                .validate_timing = optc1_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,
 
        optc32_setup_manual_trigger(optc);
 }
 
-static struct timing_generator_funcs dcn32_tg_funcs = {
+static const struct timing_generator_funcs dcn32_tg_funcs = {
                .validate_timing = optc1_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,
 
        }
 }
 
-static struct timing_generator_funcs dcn35_tg_funcs = {
+static const struct timing_generator_funcs dcn35_tg_funcs = {
                .validate_timing = optc1_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,
 
        return true;
 }
 
-static struct timing_generator_funcs dcn401_tg_funcs = {
+static const struct timing_generator_funcs dcn401_tg_funcs = {
                .validate_timing = optc1_validate_timing,
                .program_timing = optc1_program_timing,
                .setup_vertical_interrupt0 = optc1_setup_vertical_interrupt0,