1 /**
2 * Copyright © 2017 IBM Corporation
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 #include "gpio.hpp"
17
18 #include <fcntl.h>
19 #include <sys/ioctl.h>
20
21 #include <phosphor-logging/elog-errors.hpp>
22 #include <phosphor-logging/elog.hpp>
23 #include <phosphor-logging/log.hpp>
24 #include <xyz/openbmc_project/Common/error.hpp>
25
26 #include <cassert>
27
28 namespace phosphor
29 {
30 namespace gpio
31 {
32
33 using namespace phosphor::logging;
34
35 using InternalFailure =
36 sdbusplus::xyz::openbmc_project::Common::Error::InternalFailure;
37
read()38 Value GPIO::read()
39 {
40 assert(direction == Direction::input);
41
42 requestLine();
43
44 gpiohandle_data data{};
45
46 auto rc = ioctl(lineFD(), GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
47
48 if (rc < 0)
49 {
50 auto e = errno;
51 log<level::ERR>("Failed GET_LINE_VALUES ioctl", entry("ERRNO=%d", e));
52 elog<InternalFailure>();
53 }
54
55 return (data.values[0] == 0) ? Value::low : Value::high;
56 }
57
set(Value value)58 void GPIO::set(Value value)
59 {
60 assert(direction == Direction::output);
61
62 requestLine(value);
63
64 gpiohandle_data data{};
65 data.values[0] = static_cast<gpioValue_t>(value);
66
67 auto rc = ioctl(lineFD(), GPIOHANDLE_SET_LINE_VALUES_IOCTL, &data);
68 if (rc == -1)
69 {
70 auto e = errno;
71 log<level::ERR>("Failed SET_LINE_VALUES ioctl", entry("ERRNO=%d", e));
72 elog<InternalFailure>();
73 }
74 }
75
requestLine(Value defaultValue)76 void GPIO::requestLine(Value defaultValue)
77 {
78 // Only need to do this once
79 if (lineFD)
80 {
81 return;
82 }
83
84 power::util::FileDescriptor fd{open(device.c_str(), 0)};
85 if (fd() == -1)
86 {
87 auto e = errno;
88 log<level::ERR>("Failed opening GPIO device",
89 entry("DEVICE=%s", device.c_str()),
90 entry("ERRNO=%d", e));
91 elog<InternalFailure>();
92 }
93
94 // Make an ioctl call to request the GPIO line, which will
95 // return the descriptor to use to access it.
96 gpiohandle_request request{};
97 strncpy(request.consumer_label, "phosphor-power",
98 sizeof(request.consumer_label));
99
100 request.flags = (direction == Direction::input) ? GPIOHANDLE_REQUEST_INPUT
101 : GPIOHANDLE_REQUEST_OUTPUT;
102
103 request.lineoffsets[0] = gpio;
104 request.lines = 1;
105
106 if (direction == Direction::output)
107 {
108 request.default_values[0] = static_cast<gpioValue_t>(defaultValue);
109 }
110
111 auto rc = ioctl(fd(), GPIO_GET_LINEHANDLE_IOCTL, &request);
112 if (rc == -1)
113 {
114 auto e = errno;
115 log<level::ERR>("Failed GET_LINEHANDLE ioctl", entry("GPIO=%d", gpio),
116 entry("ERRNO=%d", e));
117 elog<InternalFailure>();
118 }
119
120 lineFD.set(request.fd);
121 }
122
123 } // namespace gpio
124 } // namespace phosphor
125