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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> | |
03067410 SN |
23 | #include <linux/device.h> |
24 | #include <linux/gpio.h> | |
1cad1de1 CP |
25 | |
26 | #include <sound/l3.h> | |
27 | ||
28 | /* | |
29 | * Send one byte of data to the chip. Data is latched into the chip on | |
30 | * the rising edge of the clock. | |
31 | */ | |
32 | static void sendbyte(struct l3_pins *adap, unsigned int byte) | |
33 | { | |
34 | int i; | |
35 | ||
36 | for (i = 0; i < 8; i++) { | |
03067410 | 37 | adap->setclk(adap, 0); |
1cad1de1 | 38 | udelay(adap->data_hold); |
03067410 | 39 | adap->setdat(adap, byte & 1); |
1cad1de1 | 40 | udelay(adap->data_setup); |
03067410 | 41 | adap->setclk(adap, 1); |
1cad1de1 CP |
42 | udelay(adap->clock_high); |
43 | byte >>= 1; | |
44 | } | |
45 | } | |
46 | ||
47 | /* | |
48 | * Send a set of bytes to the chip. We need to pulse the MODE line | |
49 | * between each byte, but never at the start nor at the end of the | |
50 | * transfer. | |
51 | */ | |
52 | static void sendbytes(struct l3_pins *adap, const u8 *buf, | |
53 | int len) | |
54 | { | |
55 | int i; | |
56 | ||
57 | for (i = 0; i < len; i++) { | |
58 | if (i) { | |
59 | udelay(adap->mode_hold); | |
03067410 | 60 | adap->setmode(adap, 0); |
1cad1de1 CP |
61 | udelay(adap->mode); |
62 | } | |
03067410 | 63 | adap->setmode(adap, 1); |
1cad1de1 CP |
64 | udelay(adap->mode_setup); |
65 | sendbyte(adap, buf[i]); | |
66 | } | |
67 | } | |
68 | ||
69 | int l3_write(struct l3_pins *adap, u8 addr, u8 *data, int len) | |
70 | { | |
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71 | adap->setclk(adap, 1); |
72 | adap->setdat(adap, 1); | |
73 | adap->setmode(adap, 1); | |
1cad1de1 CP |
74 | udelay(adap->mode); |
75 | ||
03067410 | 76 | adap->setmode(adap, 0); |
1cad1de1 CP |
77 | udelay(adap->mode_setup); |
78 | sendbyte(adap, addr); | |
79 | udelay(adap->mode_hold); | |
80 | ||
81 | sendbytes(adap, data, len); | |
82 | ||
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83 | adap->setclk(adap, 1); |
84 | adap->setdat(adap, 1); | |
85 | adap->setmode(adap, 0); | |
1cad1de1 CP |
86 | |
87 | return len; | |
88 | } | |
89 | EXPORT_SYMBOL_GPL(l3_write); | |
90 | ||
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91 | |
92 | static void l3_set_clk(struct l3_pins *adap, int val) | |
93 | { | |
94 | gpio_set_value(adap->gpio_clk, val); | |
95 | } | |
96 | ||
97 | static void l3_set_data(struct l3_pins *adap, int val) | |
98 | { | |
99 | gpio_set_value(adap->gpio_data, val); | |
100 | } | |
101 | ||
102 | static void l3_set_mode(struct l3_pins *adap, int val) | |
103 | { | |
104 | gpio_set_value(adap->gpio_mode, val); | |
105 | } | |
106 | ||
107 | int l3_set_gpio_ops(struct device *dev, struct l3_pins *adap) | |
108 | { | |
109 | int ret; | |
110 | ||
111 | if (!adap->use_gpios) | |
112 | return -EINVAL; | |
113 | ||
114 | ret = devm_gpio_request_one(dev, adap->gpio_data, | |
115 | GPIOF_OUT_INIT_LOW, "l3_data"); | |
116 | if (ret < 0) | |
117 | return ret; | |
118 | adap->setdat = l3_set_data; | |
119 | ||
120 | ret = devm_gpio_request_one(dev, adap->gpio_clk, | |
121 | GPIOF_OUT_INIT_LOW, "l3_clk"); | |
122 | if (ret < 0) | |
123 | return ret; | |
124 | adap->setclk = l3_set_clk; | |
125 | ||
126 | ret = devm_gpio_request_one(dev, adap->gpio_mode, | |
127 | GPIOF_OUT_INIT_LOW, "l3_mode"); | |
128 | if (ret < 0) | |
129 | return ret; | |
130 | adap->setmode = l3_set_mode; | |
131 | ||
132 | return 0; | |
133 | } | |
134 | EXPORT_SYMBOL_GPL(l3_set_gpio_ops); | |
135 | ||
1cad1de1 CP |
136 | MODULE_DESCRIPTION("L3 bit-banging driver"); |
137 | MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>"); | |
138 | MODULE_LICENSE("GPL"); |