tsiry-sandratraina.com
A modern Music Player Daemon based on Rockbox open source high quality audio player
libadwaita
audio
rust
zig
deno
mpris
rockbox
mpd
1/***************************************************************************
2 * __________ __ ___.
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
7 * \/ \/ \/ \/ \/
8 * $Id$
9 *
10 * Copyright (C) 2006 by Linus Nielsen Feltzing
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
16 *
17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
18 * KIND, either express or implied.
19 *
20 ****************************************************************************/
21#include "config.h"
22#include "cpu.h"
23#include <stdbool.h>
24#include <stdlib.h>
25#include "debug.h"
26#include "generic_i2c.h"
27
28#define MAX_I2C_INTERFACES 5
29
30static int i2c_num_ifs = 0;
31static const struct i2c_interface *i2c_if[MAX_I2C_INTERFACES];
32
33static void i2c_start(const struct i2c_interface *iface)
34{
35 iface->sda_dir(true);
36
37 iface->sda_out(1);
38 iface->scl_out(1);
39 iface->delay(iface->delay_su_sta);
40 iface->sda_out(0);
41 iface->delay(iface->delay_hd_sta);
42 iface->scl_out(0);
43 iface->delay(iface->delay_hd_dat);
44}
45
46static void i2c_stop(const struct i2c_interface *iface)
47{
48 iface->sda_dir(true);
49
50 iface->sda_out(0);
51 iface->delay(iface->delay_su_dat);
52 iface->scl_out(1);
53 iface->delay(iface->delay_su_sto);
54 iface->sda_out(1);
55}
56
57static void i2c_ack(const struct i2c_interface *iface, bool ack)
58{
59 iface->sda_dir(true);
60 iface->sda_out(!ack);
61 iface->delay(iface->delay_su_dat);
62 iface->scl_out(1);
63 iface->delay(iface->delay_thigh);
64 iface->scl_out(0);
65 iface->delay(iface->delay_hd_dat);
66}
67
68static int i2c_getack(const struct i2c_interface *iface)
69{
70 int ret = 1;
71
72 iface->sda_dir(false);
73 iface->delay(iface->delay_su_dat);
74 iface->scl_out(1);
75 iface->delay(iface->delay_thigh);
76 if (iface->sda_in())
77 ret = 0; /* ack failed */
78 iface->scl_out(0);
79 iface->delay(iface->delay_hd_dat);
80 return ret;
81}
82
83static unsigned char i2c_inb(const struct i2c_interface *iface, bool ack)
84{
85 int i;
86 unsigned char byte = 0;
87
88 iface->sda_dir(false);
89
90 /* clock in each bit, MSB first */
91 for ( i=0x80; i; i>>=1 ) {
92 iface->delay(iface->delay_su_dat);
93 iface->scl_out(1);
94 iface->delay(iface->delay_thigh);
95 if (iface->sda_in())
96 byte |= i;
97 iface->scl_out(0);
98 iface->delay(iface->delay_hd_dat);
99 }
100
101 i2c_ack(iface, ack);
102
103 return byte;
104}
105
106static int i2c_outb(const struct i2c_interface *iface, unsigned char byte)
107{
108 int i;
109
110 iface->sda_dir(true);
111
112 /* clock out each bit, MSB first */
113 for (i=0x80; i; i>>=1) {
114 iface->sda_out(i & byte);
115 iface->delay(iface->delay_su_dat);
116 iface->scl_out(1);
117 iface->delay(iface->delay_thigh);
118 iface->scl_out(0);
119 iface->delay(iface->delay_hd_dat);
120 }
121
122 return i2c_getack(iface);
123}
124
125int i2c_write_data(int bus_index, int bus_address, int address,
126 const unsigned char* buf, int count)
127{
128 int i;
129 int ret = 0;
130 const struct i2c_interface *iface = i2c_if[bus_index];
131
132 i2c_start(iface);
133 if (!i2c_outb(iface, bus_address & 0xfe))
134 {
135 ret = -2;
136 goto end;
137 }
138
139 if (address != -1)
140 {
141 if (!i2c_outb(iface, address))
142 {
143 ret = -3;
144 goto end;
145 }
146 }
147
148 for(i = 0;i < count;i++)
149 {
150 if (!i2c_outb(iface, buf[i]))
151 {
152 ret = -4;
153 break;
154 }
155 }
156
157end:
158 i2c_stop(iface);
159 return ret;
160}
161
162int i2c_read_data(int bus_index, int bus_address, int address,
163 unsigned char* buf, int count)
164{
165 int i;
166 int ret = 0;
167 const struct i2c_interface *iface = i2c_if[bus_index];
168
169 if (address != -1)
170 {
171 i2c_start(iface);
172 if (!i2c_outb(iface, bus_address & 0xfe))
173 {
174 ret = -2;
175 goto end;
176 }
177 if (!i2c_outb(iface, address))
178 {
179 ret = -3;
180 goto end;
181 }
182 }
183
184 i2c_start(iface);
185 if (!i2c_outb(iface, bus_address | 1))
186 {
187 ret = -4;
188 goto end;
189 }
190
191 for(i = 0;i < count-1;i++)
192 buf[i] = i2c_inb(iface, true);
193
194 buf[i] = i2c_inb(iface, false);
195
196end:
197 i2c_stop(iface);
198 return ret;
199}
200
201int i2c_write_read_data(int bus_index, int bus_address,
202 const unsigned char* buf_write, int count_write,
203 unsigned char* buf_read, int count_read)
204{
205 int i;
206 int ret = 0;
207 const struct i2c_interface *iface = i2c_if[bus_index];
208
209 i2c_start(iface);
210 if (!i2c_outb(iface, bus_address))
211 {
212 ret = -2;
213 goto end;
214 }
215
216 for(i = 0;i < count_write;i++)
217 {
218 if (!i2c_outb(iface, buf_write[i]))
219 {
220 ret = -3;
221 goto end;
222 }
223 }
224
225 for(i = 0;i < count_read-1;i++)
226 buf_read[i] = i2c_inb(iface, true);
227
228 buf_read[i] = i2c_inb(iface, false);
229
230end:
231 i2c_stop(iface);
232 return ret;
233}
234
235/* returns bus index which can be used as a handle, or <0 on error */
236int i2c_add_node(const struct i2c_interface *iface)
237{
238 int bus_index;
239
240 if (i2c_num_ifs == MAX_I2C_INTERFACES)
241 return -1;
242
243 bus_index = i2c_num_ifs++;
244 i2c_if[bus_index] = iface;
245
246 iface->scl_dir(true);
247
248 return bus_index;
249}