diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-20 19:39:23 -0500 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-20 19:39:23 -0500 |
commit | fc887b15d935ead2a00aef5779a18034e7c69ee1 (patch) | |
tree | 30daa1c9bafbf179047047c67d11ccd98e27d809 /drivers/tty/hvc/hvc_dcc.c | |
parent | 466c19063b4b426d5c362572787cb249fbf4296b (diff) | |
parent | df6212529c646710502657b18d8f42927f3dda81 (diff) |
Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
tty: update MAINTAINERS file due to driver movement
tty: move drivers/serial/ to drivers/tty/serial/
tty: move hvc drivers to drivers/tty/hvc/
Diffstat (limited to 'drivers/tty/hvc/hvc_dcc.c')
-rw-r--r-- | drivers/tty/hvc/hvc_dcc.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c new file mode 100644 index 000000000000..6470f63deb4b --- /dev/null +++ b/drivers/tty/hvc/hvc_dcc.c | |||
@@ -0,0 +1,133 @@ | |||
1 | /* Copyright (c) 2010, Code Aurora Forum. All rights reserved. | ||
2 | * | ||
3 | * This program is free software; you can redistribute it and/or modify | ||
4 | * it under the terms of the GNU General Public License version 2 and | ||
5 | * only version 2 as published by the Free Software Foundation. | ||
6 | * | ||
7 | * This program is distributed in the hope that it will be useful, | ||
8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
10 | * GNU General Public License for more details. | ||
11 | * | ||
12 | * You should have received a copy of the GNU General Public License | ||
13 | * along with this program; if not, write to the Free Software | ||
14 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | ||
15 | * 02110-1301, USA. | ||
16 | */ | ||
17 | |||
18 | #include <linux/console.h> | ||
19 | #include <linux/delay.h> | ||
20 | #include <linux/err.h> | ||
21 | #include <linux/init.h> | ||
22 | #include <linux/moduleparam.h> | ||
23 | #include <linux/types.h> | ||
24 | |||
25 | #include <asm/processor.h> | ||
26 | |||
27 | #include "hvc_console.h" | ||
28 | |||
29 | /* DCC Status Bits */ | ||
30 | #define DCC_STATUS_RX (1 << 30) | ||
31 | #define DCC_STATUS_TX (1 << 29) | ||
32 | |||
33 | static inline u32 __dcc_getstatus(void) | ||
34 | { | ||
35 | u32 __ret; | ||
36 | |||
37 | asm("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg" | ||
38 | : "=r" (__ret) : : "cc"); | ||
39 | |||
40 | return __ret; | ||
41 | } | ||
42 | |||
43 | |||
44 | #if defined(CONFIG_CPU_V7) | ||
45 | static inline char __dcc_getchar(void) | ||
46 | { | ||
47 | char __c; | ||
48 | |||
49 | asm("get_wait: mrc p14, 0, pc, c0, c1, 0 \n\ | ||
50 | bne get_wait \n\ | ||
51 | mrc p14, 0, %0, c0, c5, 0 @ read comms data reg" | ||
52 | : "=r" (__c) : : "cc"); | ||
53 | |||
54 | return __c; | ||
55 | } | ||
56 | #else | ||
57 | static inline char __dcc_getchar(void) | ||
58 | { | ||
59 | char __c; | ||
60 | |||
61 | asm("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg" | ||
62 | : "=r" (__c)); | ||
63 | |||
64 | return __c; | ||
65 | } | ||
66 | #endif | ||
67 | |||
68 | #if defined(CONFIG_CPU_V7) | ||
69 | static inline void __dcc_putchar(char c) | ||
70 | { | ||
71 | asm("put_wait: mrc p14, 0, pc, c0, c1, 0 \n\ | ||
72 | bcs put_wait \n\ | ||
73 | mcr p14, 0, %0, c0, c5, 0 " | ||
74 | : : "r" (c) : "cc"); | ||
75 | } | ||
76 | #else | ||
77 | static inline void __dcc_putchar(char c) | ||
78 | { | ||
79 | asm("mcr p14, 0, %0, c0, c5, 0 @ write a char" | ||
80 | : /* no output register */ | ||
81 | : "r" (c)); | ||
82 | } | ||
83 | #endif | ||
84 | |||
85 | static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count) | ||
86 | { | ||
87 | int i; | ||
88 | |||
89 | for (i = 0; i < count; i++) { | ||
90 | while (__dcc_getstatus() & DCC_STATUS_TX) | ||
91 | cpu_relax(); | ||
92 | |||
93 | __dcc_putchar((char)(buf[i] & 0xFF)); | ||
94 | } | ||
95 | |||
96 | return count; | ||
97 | } | ||
98 | |||
99 | static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count) | ||
100 | { | ||
101 | int i; | ||
102 | |||
103 | for (i = 0; i < count; ++i) { | ||
104 | int c = -1; | ||
105 | |||
106 | if (__dcc_getstatus() & DCC_STATUS_RX) | ||
107 | c = __dcc_getchar(); | ||
108 | if (c < 0) | ||
109 | break; | ||
110 | buf[i] = c; | ||
111 | } | ||
112 | |||
113 | return i; | ||
114 | } | ||
115 | |||
116 | static const struct hv_ops hvc_dcc_get_put_ops = { | ||
117 | .get_chars = hvc_dcc_get_chars, | ||
118 | .put_chars = hvc_dcc_put_chars, | ||
119 | }; | ||
120 | |||
121 | static int __init hvc_dcc_console_init(void) | ||
122 | { | ||
123 | hvc_instantiate(0, 0, &hvc_dcc_get_put_ops); | ||
124 | return 0; | ||
125 | } | ||
126 | console_initcall(hvc_dcc_console_init); | ||
127 | |||
128 | static int __init hvc_dcc_init(void) | ||
129 | { | ||
130 | hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128); | ||
131 | return 0; | ||
132 | } | ||
133 | device_initcall(hvc_dcc_init); | ||