static const struct old_serial_port *serstate;
 static int timeouts;
 
+static int spk_serial_out(struct spk_synth *in_synth, const char ch);
+struct spk_io_ops spk_serial_io_ops = {
+       .synth_out = spk_serial_out,
+};
+EXPORT_SYMBOL_GPL(spk_serial_io_ops);
+
 const struct old_serial_port *spk_serial_init(int index)
 {
        int baud = 9600, quot = 0;
        }
        return 0;
 }
-EXPORT_SYMBOL_GPL(spk_serial_out);
 
 void spk_serial_release(void)
 {
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = synth_probe,
        .release = accent_release,
        .synth_immediate = synth_immediate,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = spk_serial_synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
                set_current_state(TASK_INTERRUPTIBLE);
                full_time_val = full_time->u.n.value;
                spin_unlock_irqrestore(&speakup_info.spinlock, flags);
-               if (!spk_serial_out(synth, ch)) {
+               if (!synth->io_ops->synth_out(synth, ch)) {
                        outb(UART_MCR_DTR, speakup_info.port_tts + UART_MCR);
                        outb(UART_MCR_DTR | UART_MCR_RTS,
                                        speakup_info.port_tts + UART_MCR);
                        full_time_val = full_time->u.n.value;
                        delay_time_val = delay_time->u.n.value;
                        spin_unlock_irqrestore(&speakup_info.spinlock, flags);
-                       if (spk_serial_out(synth, synth->procspeech))
+                       if (synth->io_ops->synth_out(synth, synth->procspeech))
                                schedule_timeout(msecs_to_jiffies
                                                 (delay_time_val));
                        else
                synth_buffer_getc();
                spin_unlock_irqrestore(&speakup_info.spinlock, flags);
        }
-       spk_serial_out(synth, PROCSPEECH);
+       synth->io_ops->synth_out(synth, PROCSPEECH);
 }
 
 module_param_named(ser, synth_apollo.ser, int, 0444);
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
                udelay(1);
        }
        outb(SYNTH_CLEAR, speakup_info.port_tts);
-       spk_serial_out(synth, PROCSPEECH);
+       synth->io_ops->synth_out(synth, PROCSPEECH);
 }
 
 static void synth_version(struct spk_synth *synth)
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = spk_serial_synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = spk_serial_synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
                spin_unlock_irqrestore(&speakup_info.spinlock, flags);
                if (ch == '\n')
                        ch = 0x0D;
-               if (synth_full() || !spk_serial_out(synth, ch)) {
+               if (synth_full() || !synth->io_ops->synth_out(synth, ch)) {
                        schedule_timeout(msecs_to_jiffies(delay_time_val));
                        continue;
                }
                        in_escape = 0;
                else if (ch <= SPACE) {
                        if (!in_escape && strchr(",.!?;:", last))
-                               spk_serial_out(synth, PROCSPEECH);
+                               synth->io_ops->synth_out(synth, PROCSPEECH);
                        if (time_after_eq(jiffies, jiff_max)) {
                                if (!in_escape)
-                                       spk_serial_out(synth, PROCSPEECH);
+                                       synth->io_ops->synth_out(synth, PROCSPEECH);
                                spin_lock_irqsave(&speakup_info.spinlock,
                                                        flags);
                                jiffy_delta_val = jiffy_delta->u.n.value;
                last = ch;
        }
        if (!in_escape)
-               spk_serial_out(synth, PROCSPEECH);
+               synth->io_ops->synth_out(synth, PROCSPEECH);
 }
 
 static void synth_flush(struct spk_synth *synth)
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = synth_probe,
        .release = dtpc_release,
        .synth_immediate = synth_immediate,
 
        .vars = vars,
        .default_pitch = ap_defaults,
        .default_vol = g5_defaults,
+       .io_ops = &spk_serial_io_ops,
        .probe = spk_serial_synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
                spin_unlock_irqrestore(&speakup_info.spinlock, flags);
                if (ch == '\n')
                        ch = 0x0D;
-               if (synth_full_val || !spk_serial_out(synth, ch)) {
+               if (synth_full_val || !synth->io_ops->synth_out(synth, ch)) {
                        schedule_timeout(msecs_to_jiffies(delay_time_val));
                        continue;
                }
                        in_escape = 0;
                else if (ch <= SPACE) {
                        if (!in_escape && strchr(",.!?;:", last))
-                               spk_serial_out(synth, PROCSPEECH);
+                               synth->io_ops->synth_out(synth, PROCSPEECH);
                        if (time_after_eq(jiffies, jiff_max)) {
                                if (!in_escape)
-                                       spk_serial_out(synth, PROCSPEECH);
+                                       synth->io_ops->synth_out(synth, PROCSPEECH);
                                spin_lock_irqsave(&speakup_info.spinlock,
                                                flags);
                                jiffy_delta_val = jiffy_delta->u.n.value;
                last = ch;
        }
        if (!in_escape)
-               spk_serial_out(synth, PROCSPEECH);
+               synth->io_ops->synth_out(synth, PROCSPEECH);
 }
 
 static void synth_flush(struct spk_synth *synth)
 {
        if (in_escape)
                /* if in command output ']' so we don't get an error */
-               spk_serial_out(synth, ']');
+               synth->io_ops->synth_out(synth, ']');
        in_escape = 0;
        is_flushing = 1;
-       spk_serial_out(synth, SYNTH_CLEAR);
+       synth->io_ops->synth_out(synth, SYNTH_CLEAR);
 }
 
 module_param_named(ser, synth_dectlk.ser, int, 0444);
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = synth_probe,
        .release = dtlk_release,
        .synth_immediate = synth_immediate,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = spk_serial_synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = synth_probe,
        .release = keynote_release,
        .synth_immediate = synth_immediate,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = NULL,
        .probe = softsynth_probe,
        .release = softsynth_release,
        .synth_immediate = NULL,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = spk_serial_synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
 
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
+       .io_ops = &spk_serial_io_ops,
        .probe = spk_serial_synth_probe,
        .release = spk_serial_release,
        .synth_immediate = spk_synth_immediate,
 
 int spk_wait_for_xmitr(struct spk_synth *in_synth);
 unsigned char spk_serial_in(void);
 unsigned char spk_serial_in_nowait(void);
-int spk_serial_out(struct spk_synth *in_synth, const char ch);
 void spk_serial_release(void);
 
 void synth_buffer_skip_nonlatin1(void);
 
 extern struct var_t synth_time_vars[];
 
+extern struct spk_io_ops spk_serial_io_ops;
+
 #endif
 
        unsigned char currindex;
 };
 
+struct spk_synth;
+
+struct spk_io_ops {
+       int (*synth_out)(struct spk_synth *synth, const char ch);
+};
+
 struct spk_synth {
        const char *name;
        const char *version;
        struct var_t *vars;
        int *default_pitch;
        int *default_vol;
+       struct spk_io_ops *io_ops;
        int (*probe)(struct spk_synth *synth);
        void (*release)(void);
        const char *(*synth_immediate)(struct spk_synth *synth,
 
                spin_unlock_irqrestore(&speakup_info.spinlock, flags);
                if (ch == '\n')
                        ch = synth->procspeech;
-               if (!spk_serial_out(synth, ch)) {
+               if (!synth->io_ops->synth_out(synth, ch)) {
                        schedule_timeout(msecs_to_jiffies(full_time_val));
                        continue;
                }
                        delay_time_val = delay_time->u.n.value;
                        full_time_val = full_time->u.n.value;
                        spin_unlock_irqrestore(&speakup_info.spinlock, flags);
-                       if (spk_serial_out(synth, synth->procspeech))
+                       if (synth->io_ops->synth_out(synth, synth->procspeech))
                                schedule_timeout(
                                        msecs_to_jiffies(delay_time_val));
                        else
                synth_buffer_getc();
                spin_unlock_irqrestore(&speakup_info.spinlock, flags);
        }
-       spk_serial_out(synth, synth->procspeech);
+       synth->io_ops->synth_out(synth, synth->procspeech);
 }
 EXPORT_SYMBOL_GPL(spk_do_catch_up);
 
 
 void spk_synth_flush(struct spk_synth *synth)
 {
-       spk_serial_out(synth, synth->clear);
+       synth->io_ops->synth_out(synth, synth->clear);
 }
 EXPORT_SYMBOL_GPL(spk_synth_flush);