Commit | Line | Data |
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1cad1de1 CP |
1 | /* |
2 | * L3 code | |
3 | * | |
4 | * Copyright (C) 2008, Christian Pellegrin <chripell@evolware.org> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * | |
11 | * based on: | |
12 | * | |
13 | * L3 bus algorithm module. | |
14 | * | |
15 | * Copyright (C) 2001 Russell King, All Rights Reserved. | |
16 | * | |
17 | * | |
18 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/delay.h> | |
23 | ||
24 | #include <sound/l3.h> | |
25 | ||
26 | /* | |
27 | * Send one byte of data to the chip. Data is latched into the chip on | |
28 | * the rising edge of the clock. | |
29 | */ | |
30 | static void sendbyte(struct l3_pins *adap, unsigned int byte) | |
31 | { | |
32 | int i; | |
33 | ||
34 | for (i = 0; i < 8; i++) { | |
35 | adap->setclk(0); | |
36 | udelay(adap->data_hold); | |
37 | adap->setdat(byte & 1); | |
38 | udelay(adap->data_setup); | |
39 | adap->setclk(1); | |
40 | udelay(adap->clock_high); | |
41 | byte >>= 1; | |
42 | } | |
43 | } | |
44 | ||
45 | /* | |
46 | * Send a set of bytes to the chip. We need to pulse the MODE line | |
47 | * between each byte, but never at the start nor at the end of the | |
48 | * transfer. | |
49 | */ | |
50 | static void sendbytes(struct l3_pins *adap, const u8 *buf, | |
51 | int len) | |
52 | { | |
53 | int i; | |
54 | ||
55 | for (i = 0; i < len; i++) { | |
56 | if (i) { | |
57 | udelay(adap->mode_hold); | |
58 | adap->setmode(0); | |
59 | udelay(adap->mode); | |
60 | } | |
61 | adap->setmode(1); | |
62 | udelay(adap->mode_setup); | |
63 | sendbyte(adap, buf[i]); | |
64 | } | |
65 | } | |
66 | ||
67 | int l3_write(struct l3_pins *adap, u8 addr, u8 *data, int len) | |
68 | { | |
69 | adap->setclk(1); | |
70 | adap->setdat(1); | |
71 | adap->setmode(1); | |
72 | udelay(adap->mode); | |
73 | ||
74 | adap->setmode(0); | |
75 | udelay(adap->mode_setup); | |
76 | sendbyte(adap, addr); | |
77 | udelay(adap->mode_hold); | |
78 | ||
79 | sendbytes(adap, data, len); | |
80 | ||
81 | adap->setclk(1); | |
82 | adap->setdat(1); | |
83 | adap->setmode(0); | |
84 | ||
85 | return len; | |
86 | } | |
87 | EXPORT_SYMBOL_GPL(l3_write); | |
88 | ||
89 | MODULE_DESCRIPTION("L3 bit-banging driver"); | |
90 | MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>"); | |
91 | MODULE_LICENSE("GPL"); |