Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#include <linux/console.h>
2#include <linux/types.h>
3#include <linux/wait.h>
4
5#include "speakup.h"
6#include "spk_priv.h"
7
8#define SYNTH_BUF_SIZE 8192 /* currently 8K bytes */
9
10static u16 synth_buffer[SYNTH_BUF_SIZE]; /* guess what this is for! */
11static u16 *buff_in = synth_buffer;
12static u16 *buff_out = synth_buffer;
13static u16 *buffer_end = synth_buffer + SYNTH_BUF_SIZE - 1;
14
15/* These try to throttle applications by stopping the TTYs
16 * Note: we need to make sure that we will restart them eventually, which is
17 * usually not possible to do from the notifiers. TODO: it should be possible
18 * starting from linux 2.6.26.
19 *
20 * So we only stop when we know alive == 1 (else we discard the data anyway),
21 * and the alive synth will eventually call start_ttys from the thread context.
22 */
23void speakup_start_ttys(void)
24{
25 int i;
26
27 for (i = 0; i < MAX_NR_CONSOLES; i++) {
28 if (speakup_console[i] && speakup_console[i]->tty_stopped)
29 continue;
30 if ((vc_cons[i].d) && (vc_cons[i].d->port.tty))
31 start_tty(vc_cons[i].d->port.tty);
32 }
33}
34EXPORT_SYMBOL_GPL(speakup_start_ttys);
35
36static void speakup_stop_ttys(void)
37{
38 int i;
39
40 for (i = 0; i < MAX_NR_CONSOLES; i++)
41 if ((vc_cons[i].d && (vc_cons[i].d->port.tty)))
42 stop_tty(vc_cons[i].d->port.tty);
43}
44
45static int synth_buffer_free(void)
46{
47 int chars_free;
48
49 if (buff_in >= buff_out)
50 chars_free = SYNTH_BUF_SIZE - (buff_in - buff_out);
51 else
52 chars_free = buff_out - buff_in;
53 return chars_free;
54}
55
56int synth_buffer_empty(void)
57{
58 return (buff_in == buff_out);
59}
60EXPORT_SYMBOL_GPL(synth_buffer_empty);
61
62void synth_buffer_add(u16 ch)
63{
64 if (!synth->alive) {
65 /* This makes sure that we won't stop TTYs if there is no synth
66 * to restart them
67 */
68 return;
69 }
70 if (synth_buffer_free() <= 100) {
71 synth_start();
72 speakup_stop_ttys();
73 }
74 if (synth_buffer_free() <= 1)
75 return;
76 *buff_in++ = ch;
77 if (buff_in > buffer_end)
78 buff_in = synth_buffer;
79}
80
81u16 synth_buffer_getc(void)
82{
83 u16 ch;
84
85 if (buff_out == buff_in)
86 return 0;
87 ch = *buff_out++;
88 if (buff_out > buffer_end)
89 buff_out = synth_buffer;
90 return ch;
91}
92EXPORT_SYMBOL_GPL(synth_buffer_getc);
93
94u16 synth_buffer_peek(void)
95{
96 if (buff_out == buff_in)
97 return 0;
98 return *buff_out;
99}
100EXPORT_SYMBOL_GPL(synth_buffer_peek);
101
102void synth_buffer_skip_nonlatin1(void)
103{
104 while (buff_out != buff_in) {
105 if (*buff_out < 0x100)
106 return;
107 buff_out++;
108 if (buff_out > buffer_end)
109 buff_out = synth_buffer;
110 }
111}
112EXPORT_SYMBOL_GPL(synth_buffer_skip_nonlatin1);
113
114void synth_buffer_clear(void)
115{
116 buff_in = synth_buffer;
117 buff_out = synth_buffer;
118}
119EXPORT_SYMBOL_GPL(synth_buffer_clear);