| #include <linux/console.h> |
| #include <linux/types.h> |
| #include <linux/wait.h> |
| |
| #include "speakup.h" |
| #include "spk_priv.h" |
| |
| #define SYNTH_BUF_SIZE 8192 /* currently 8K bytes */ |
| |
| static u16 synth_buffer[SYNTH_BUF_SIZE]; /* guess what this is for! */ |
| static u16 *buff_in = synth_buffer; |
| static u16 *buff_out = synth_buffer; |
| static u16 *buffer_end = synth_buffer + SYNTH_BUF_SIZE - 1; |
| |
| /* These try to throttle applications by stopping the TTYs |
| * Note: we need to make sure that we will restart them eventually, which is |
| * usually not possible to do from the notifiers. TODO: it should be possible |
| * starting from linux 2.6.26. |
| * |
| * So we only stop when we know alive == 1 (else we discard the data anyway), |
| * and the alive synth will eventually call start_ttys from the thread context. |
| */ |
| void speakup_start_ttys(void) |
| { |
| int i; |
| |
| for (i = 0; i < MAX_NR_CONSOLES; i++) { |
| if (speakup_console[i] && speakup_console[i]->tty_stopped) |
| continue; |
| if (vc_cons[i].d && vc_cons[i].d->port.tty) |
| start_tty(vc_cons[i].d->port.tty); |
| } |
| } |
| EXPORT_SYMBOL_GPL(speakup_start_ttys); |
| |
| static void speakup_stop_ttys(void) |
| { |
| int i; |
| |
| for (i = 0; i < MAX_NR_CONSOLES; i++) |
| if (vc_cons[i].d && vc_cons[i].d->port.tty) |
| stop_tty(vc_cons[i].d->port.tty); |
| } |
| |
| static int synth_buffer_free(void) |
| { |
| int chars_free; |
| |
| if (buff_in >= buff_out) |
| chars_free = SYNTH_BUF_SIZE - (buff_in - buff_out); |
| else |
| chars_free = buff_out - buff_in; |
| return chars_free; |
| } |
| |
| int synth_buffer_empty(void) |
| { |
| return (buff_in == buff_out); |
| } |
| EXPORT_SYMBOL_GPL(synth_buffer_empty); |
| |
| void synth_buffer_add(u16 ch) |
| { |
| if (!synth->alive) { |
| /* This makes sure that we won't stop TTYs if there is no synth |
| * to restart them |
| */ |
| return; |
| } |
| if (synth_buffer_free() <= 100) { |
| synth_start(); |
| speakup_stop_ttys(); |
| } |
| if (synth_buffer_free() <= 1) |
| return; |
| *buff_in++ = ch; |
| if (buff_in > buffer_end) |
| buff_in = synth_buffer; |
| } |
| |
| u16 synth_buffer_getc(void) |
| { |
| u16 ch; |
| |
| if (buff_out == buff_in) |
| return 0; |
| ch = *buff_out++; |
| if (buff_out > buffer_end) |
| buff_out = synth_buffer; |
| return ch; |
| } |
| EXPORT_SYMBOL_GPL(synth_buffer_getc); |
| |
| u16 synth_buffer_peek(void) |
| { |
| if (buff_out == buff_in) |
| return 0; |
| return *buff_out; |
| } |
| EXPORT_SYMBOL_GPL(synth_buffer_peek); |
| |
| void synth_buffer_skip_nonlatin1(void) |
| { |
| while (buff_out != buff_in) { |
| if (*buff_out < 0x100) |
| return; |
| buff_out++; |
| if (buff_out > buffer_end) |
| buff_out = synth_buffer; |
| } |
| } |
| EXPORT_SYMBOL_GPL(synth_buffer_skip_nonlatin1); |
| |
| void synth_buffer_clear(void) |
| { |
| buff_in = synth_buffer; |
| buff_out = synth_buffer; |
| } |
| EXPORT_SYMBOL_GPL(synth_buffer_clear); |