diff options
author | Shawn S <shawnshen@google.com> | 2015-10-20 14:36:22 -0700 |
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committer | Shawn S <shawnshen@google.com> | 2015-10-27 10:45:46 -0700 |
commit | 66566d404e7dc463b3b7b117a034f1206367e038 (patch) | |
tree | 45c36e11976d18ea45412bee32c32b9bee37cff1 | |
parent | e9f549b42c29abb6f58935d0d77591df0705320b (diff) | |
download | common-66566d404e7dc463b3b7b117a034f1206367e038.tar.gz |
Brillo GPIO sample: write to output pin and read input pin
Usage: gpio_playground --gin=28 --gout=24 --goffset=902
BUG:24751824
Change-Id: Id79379b1eccf83d61baac6b044eb74d48cd2180f
-rw-r--r-- | brillo_gpios/AndroidProducts.mk | 16 | ||||
-rw-r--r-- | brillo_gpios/README | 43 | ||||
-rw-r--r-- | brillo_gpios/brillo_gpios.mk | 22 | ||||
-rw-r--r-- | brillo_gpios/src/gpio_playground/Android.mk | 24 | ||||
-rw-r--r-- | brillo_gpios/src/gpio_playground/gpio_playground.cpp | 210 | ||||
-rw-r--r-- | brillo_gpios/vendorsetup.sh | 1 |
6 files changed, 316 insertions, 0 deletions
diff --git a/brillo_gpios/AndroidProducts.mk b/brillo_gpios/AndroidProducts.mk new file mode 100644 index 0000000..e31e144 --- /dev/null +++ b/brillo_gpios/AndroidProducts.mk @@ -0,0 +1,16 @@ +# +# Copyright 2015 The Android Open Source Project +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +PRODUCT_MAKEFILES := $(LOCAL_DIR)/brillo_gpios.mk diff --git a/brillo_gpios/README b/brillo_gpios/README new file mode 100644 index 0000000..be80916 --- /dev/null +++ b/brillo_gpios/README @@ -0,0 +1,43 @@ +README for Brillo GPIO sample + +This GPIO sample demonstrates how to set up GPIO and write/read to GPIO pins. +Specifically this app does the following. + + - Export an input and output GPIO pins + - Set output e.g. pin 24 direction to "out" and value to 1 + - Set input e.g. pin 28 direction to "in" and edge to "both" + - Read input pin by polling + - Once input pin is triggered to input value 1, set output value to 0 + +Once built, you can find the binary inside your tree at: + +out/target/product/dragonboard/symbols/system/bin/gpio_playground + +Do the following to deploy the sample: + - adb root + - adb remount + - adb sync + +Hardware setup: + - You need to connect a GPIO pin as output to an LED + - You need to connect a GPIO pin as input to a push button switch + +Do the following to run the sample on Dragonboard and check logs for info: + - Open a shell window and run: adb logcat + - Open another shell window and run: + - Default input pin 28 and output pin 24 + - adb shell '/system/bin/gpio_playground &' + - Choose your own output and input pins + - adb shell '/system/bin/gpio_playground --gin=<input> --gout=<output> &' + - For example, adb shell '/system/bin/gpio_playground --gin=28 --gout=24 &' + - Observe the logging info from the first window + - Observe that the LED of pin 24 is turned on + - Now push the switch of pin 28 and see that the LED gets turned off + +Notes: + - There is a GPIO port offset defined by const kDefaultGpioOffset that depends + on what kind of boards you use. For Dragonboard it is 902. This offset can + also be configured by a commandline parameter. + - There is an output pin and input pin defined by const kDefaultGpioOut and + kDefaultGpioIn respectively. They can both be configured by commandline + parameters. diff --git a/brillo_gpios/brillo_gpios.mk b/brillo_gpios/brillo_gpios.mk new file mode 100644 index 0000000..2c92214 --- /dev/null +++ b/brillo_gpios/brillo_gpios.mk @@ -0,0 +1,22 @@ +# +# Copyright 2015 The Android Open Source Project +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +$(call inherit-product, device/generic/brillo/brillo_base.mk) + +PRODUCT_NAME := brillo_gpios +PRODUCT_BRAND := Brillo + +PRODUCT_DEVICE := dragonboard +PRODUCT_PACKAGES += gpio_playground diff --git a/brillo_gpios/src/gpio_playground/Android.mk b/brillo_gpios/src/gpio_playground/Android.mk new file mode 100644 index 0000000..275151f --- /dev/null +++ b/brillo_gpios/src/gpio_playground/Android.mk @@ -0,0 +1,24 @@ +# +# Copyright 2015 The Android Open Source Project +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +LOCAL_PATH := $(call my-dir) + +include $(CLEAR_VARS) +LOCAL_MODULE := gpio_playground +LOCAL_SRC_FILES := gpio_playground.cpp +LOCAL_SHARED_LIBRARIES := libchrome libchromeos libchromeos-stream +LOCAL_C_INCLUDES := external/gtest/include +LOCAL_CFLAGS := -Wall -Werror +include $(BUILD_EXECUTABLE) diff --git a/brillo_gpios/src/gpio_playground/gpio_playground.cpp b/brillo_gpios/src/gpio_playground/gpio_playground.cpp new file mode 100644 index 0000000..64e3d0e --- /dev/null +++ b/brillo_gpios/src/gpio_playground/gpio_playground.cpp @@ -0,0 +1,210 @@ +/* Copyright 2015 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <string> +#include <sys/poll.h> +#include <sys/signalfd.h> +#include <sys/timerfd.h> + +#include <base/files/file_path.h> +#include <base/format_macros.h> +#include <base/logging.h> +#include <base/strings/stringprintf.h> +#include <base/strings/string_number_conversions.h> +#include <base/strings/string_util.h> + +#include <brillo/flag_helper.h> +#include <brillo/streams/file_stream.h> +#include <brillo/streams/stream_utils.h> + +// Define defaults that work on the Dragonboard 410c. +const int kDefaultGpioPortOffset = 902; +const int kDefaultGpioOut = 24; +const int kDefaultGpioIn = 28; + +// GPIO sysfs path +const char* const kGPIOSysfsPath = "/sys/class/gpio"; +// GPIO polling timeout in milliseconds +const int kPollTimeoutMsecs = 3000; /* 3 seconds */ +const int kBufSize = 10; + +namespace { + +/* + * Get a file stream for GPIO export + * bool write: access mode with true for write + * return: file stream pointer + */ +brillo::StreamPtr GetGPIOExportStream(bool write) { + std::string gpio_path; + gpio_path = base::StringPrintf("%s/export", kGPIOSysfsPath); + base::FilePath dev_path{gpio_path}; + auto access_mode = brillo::stream_utils::MakeAccessMode(!write, write); + return brillo::FileStream::Open( + dev_path, access_mode, brillo::FileStream::Disposition::OPEN_EXISTING, + nullptr); +} + +/* + * Get a file stream for GPIO data + * int gpio: GPIO pin number + * std::string type: GPIO type e.g. direction, edge, value + * bool write: access mode with true for write + * return: file stream pointer + */ +brillo::StreamPtr GetGPIODataStream(int gpio, const std::string type, bool write) { + std::string gpio_path; + gpio_path = base::StringPrintf("%s/gpio%d/%s", kGPIOSysfsPath, gpio, type.c_str()); + base::FilePath dev_path{gpio_path}; + auto access_mode = brillo::stream_utils::MakeAccessMode(!write, write); + return brillo::FileStream::Open( + dev_path, access_mode, brillo::FileStream::Disposition::OPEN_EXISTING, + nullptr); +} + +} // anonymous namespace + +/* + * Export GPIO to user space + * int gpio: GPIO pin number + */ +void export_gpio(int gpio) { + + brillo::StreamPtr stream = GetGPIOExportStream(true); + if (!stream) + return; + + std::string value = base::StringPrintf("%d", gpio); + stream->WriteAllBlocking(value.data(), value.size(), nullptr); +} + +/* + * Write to GPIO + * std::string type: what GPIO type i.e. direction, value, edge + * std::string v: value to be written + * return: true + */ +bool write_gpio(int gpio, const std::string type, std::string v) { + + brillo::StreamPtr stream = GetGPIODataStream(gpio, type, true); + if (!stream) + return false; + + stream->WriteAllBlocking(v.data(), v.size(), nullptr); + return true; +} + +/* + * This method polls GPIO pin for 0 -> 1 transition. + * int gpio: GPIO pin to be polled. + * return: + * true if polling reads back successfully + * false if GPIO open error or polling error + */ +bool poll_gpio(int gpio) { + char buf[kBufSize]; + struct pollfd fdset[1]; + int nfds = 1; + int fd = -1; + int rc = -1; + int len = -1; + + std::string gpio_path; + gpio_path = base::StringPrintf("%s/gpio%d/value", kGPIOSysfsPath, gpio); + fd = open(gpio_path.c_str(), O_RDONLY | O_NONBLOCK ); + if (fd < 0) { + PLOG(ERROR) << "GPIO open error"; + return false; + } + + // Use this sawZeroValue to ignore the first spurious interrupt. + bool sawZeroValue = false; + + while(1) { + memset((void*)fdset, 0, sizeof(fdset)); + fdset[0].fd = fd; + fdset[0].events = POLLPRI; + + rc = poll(fdset, nfds, kPollTimeoutMsecs); + if (rc < 0) { + PLOG(ERROR) << "poll() failed!"; + close(fd); + return false; + } else if (rc == 0) { + LOG(INFO) << "polling..."; + } else if (fdset[0].revents & POLLPRI) { + len = read(fdset[0].fd, buf, kBufSize - 1); + lseek(fdset[0].fd, 0, SEEK_SET); + if (len >= 0) { + buf[len] = '\0'; + } + if (buf[0] == '0') { + LOG(INFO) << "First interrupt with value 0 ignored."; + sawZeroValue = true; + continue; + } + if (sawZeroValue && buf[0] == '1') { + LOG(INFO) << "GPIO pin reset and interrupt with value 1 caught."; + close(fd); + return true; + } + } + } + close(fd); + return true; +} + +int main(int argc, char **argv) { + int gpio_out = -1; + int gpio_in = -1; + int goffset = kDefaultGpioPortOffset; + + DEFINE_int32(gin, 28, "GPIO input"); + DEFINE_int32(gout, 24, "GPIO output"); + DEFINE_int32(goffset, 902, "GPIO port offset for Dragonboard"); + brillo::FlagHelper::Init(argc, argv, "GPIO Playground."); + + if (argc == 1 || argc == 3 || argc == 4) { + if (FLAGS_goffset) { + goffset = FLAGS_goffset; + } + gpio_out = FLAGS_gout + goffset; + gpio_in = FLAGS_gin + goffset; + } else { + printf("Pass input & output GPIO pin as follows\n"); + printf("adb shell '/system/bin/gpio_playground --gin=28 --gout=24 --goffset=902 &'\n"); + return -1; + } + + LOG(INFO) << "Export pin " << kDefaultGpioOut << " to userspace"; + export_gpio(gpio_out); + LOG(INFO) << "Set pin " << kDefaultGpioOut << " direction to out"; + write_gpio(gpio_out, "direction", "out"); + LOG(INFO) << "Set pin " << kDefaultGpioOut << " value to 1"; + write_gpio(gpio_out, "value", "1"); + + LOG(INFO) << "Export pin " << kDefaultGpioIn << " to userspace"; + export_gpio(gpio_in); + LOG(INFO) << "Set pin " << kDefaultGpioIn << " direction to in"; + write_gpio(gpio_in, "direction", "in"); + LOG(INFO) << "Set pin " << kDefaultGpioIn << " edge to both"; + write_gpio(gpio_in, "edge", "both"); + + if (poll_gpio(gpio_in)) { + LOG(INFO) << "Pin " << kDefaultGpioIn << " pushed. Now turn off LED"; + write_gpio(gpio_out, "value", "0"); + } + return 0; +} diff --git a/brillo_gpios/vendorsetup.sh b/brillo_gpios/vendorsetup.sh new file mode 100644 index 0000000..cdec5ff --- /dev/null +++ b/brillo_gpios/vendorsetup.sh @@ -0,0 +1 @@ +add_lunch_combo brillo_gpios-userdebug |