1 | // SPDX-License-Identifier: GPL-2.0 |
---|---|
2 | #include <linux/console.h> |
3 | #include <linux/types.h> |
4 | #include <linux/wait.h> |
5 | |
6 | #include "speakup.h" |
7 | #include "spk_priv.h" |
8 | |
9 | #define SYNTH_BUF_SIZE 8192 /* currently 8K bytes */ |
10 | |
11 | static u16 synth_buffer[SYNTH_BUF_SIZE]; /* guess what this is for! */ |
12 | static u16 *buff_in = synth_buffer; |
13 | static u16 *buff_out = synth_buffer; |
14 | static u16 *buffer_end = synth_buffer + SYNTH_BUF_SIZE - 1; |
15 | |
16 | /* These try to throttle applications by stopping the TTYs |
17 | * Note: we need to make sure that we will restart them eventually, which is |
18 | * usually not possible to do from the notifiers. TODO: it should be possible |
19 | * starting from linux 2.6.26. |
20 | * |
21 | * So we only stop when we know alive == 1 (else we discard the data anyway), |
22 | * and the alive synth will eventually call start_ttys from the thread context. |
23 | */ |
24 | void speakup_start_ttys(void) |
25 | { |
26 | int i; |
27 | |
28 | for (i = 0; i < MAX_NR_CONSOLES; i++) { |
29 | if (speakup_console[i] && speakup_console[i]->tty_stopped) |
30 | continue; |
31 | if (vc_cons[i].d && vc_cons[i].d->port.tty) |
32 | start_tty(tty: vc_cons[i].d->port.tty); |
33 | } |
34 | } |
35 | EXPORT_SYMBOL_GPL(speakup_start_ttys); |
36 | |
37 | static void speakup_stop_ttys(void) |
38 | { |
39 | int i; |
40 | |
41 | for (i = 0; i < MAX_NR_CONSOLES; i++) |
42 | if (vc_cons[i].d && vc_cons[i].d->port.tty) |
43 | stop_tty(tty: vc_cons[i].d->port.tty); |
44 | } |
45 | |
46 | static int synth_buffer_free(void) |
47 | { |
48 | int chars_free; |
49 | |
50 | if (buff_in >= buff_out) |
51 | chars_free = SYNTH_BUF_SIZE - (buff_in - buff_out); |
52 | else |
53 | chars_free = buff_out - buff_in; |
54 | return chars_free; |
55 | } |
56 | |
57 | int synth_buffer_empty(void) |
58 | { |
59 | return (buff_in == buff_out); |
60 | } |
61 | EXPORT_SYMBOL_GPL(synth_buffer_empty); |
62 | |
63 | void synth_buffer_add(u16 ch) |
64 | { |
65 | if (!synth->alive) { |
66 | /* This makes sure that we won't stop TTYs if there is no synth |
67 | * to restart them |
68 | */ |
69 | return; |
70 | } |
71 | if (synth_buffer_free() <= 100) { |
72 | synth_start(); |
73 | speakup_stop_ttys(); |
74 | } |
75 | if (synth_buffer_free() <= 1) |
76 | return; |
77 | *buff_in++ = ch; |
78 | if (buff_in > buffer_end) |
79 | buff_in = synth_buffer; |
80 | /* We have written something to the speech synthesis, so we are not |
81 | * paused any more. |
82 | */ |
83 | spk_paused = false; |
84 | } |
85 | |
86 | u16 synth_buffer_getc(void) |
87 | { |
88 | u16 ch; |
89 | |
90 | if (buff_out == buff_in) |
91 | return 0; |
92 | ch = *buff_out++; |
93 | if (buff_out > buffer_end) |
94 | buff_out = synth_buffer; |
95 | return ch; |
96 | } |
97 | EXPORT_SYMBOL_GPL(synth_buffer_getc); |
98 | |
99 | u16 synth_buffer_peek(void) |
100 | { |
101 | if (buff_out == buff_in) |
102 | return 0; |
103 | return *buff_out; |
104 | } |
105 | EXPORT_SYMBOL_GPL(synth_buffer_peek); |
106 | |
107 | void synth_buffer_skip_nonlatin1(void) |
108 | { |
109 | while (buff_out != buff_in) { |
110 | if (*buff_out < 0x100) |
111 | return; |
112 | buff_out++; |
113 | if (buff_out > buffer_end) |
114 | buff_out = synth_buffer; |
115 | } |
116 | } |
117 | EXPORT_SYMBOL_GPL(synth_buffer_skip_nonlatin1); |
118 | |
119 | void synth_buffer_clear(void) |
120 | { |
121 | buff_in = synth_buffer; |
122 | buff_out = synth_buffer; |
123 | } |
124 | EXPORT_SYMBOL_GPL(synth_buffer_clear); |
125 |