Define the developer interface for GPIO.

This CL defines the C API that will be used by developers.

Bug: 26778811

Change-Id: I1d5d3e3232f058eb573df49a02ee9f3da1e9e9ce

3 files changed, 206 insertions, 21 deletions

diff --git a/include/peripheralmanager/errors.h b/include/peripheralmanager/errors.h
new file mode 100644
index 0000000..d0019ce
--- /dev/null
+++ b/include/peripheralmanager/errors.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef SYSTEM_PERIPHERALMANAGER_ERRORS_H_
+#define SYSTEM_PERIPHERALMANAGER_ERRORS_H_
+
+#include <sys/cdefs.h>
+
+enum peripheral_error_t {
+  PERIPHERAL_IO_OK,
+  PERIPHERAL_IO_UNKNOWN_DEVICE,
+  PERIPHERAL_IO_DEVICE_IN_USE,
+  PERIPHERAL_IO_FUNCTION_NOT_IMPLEMENTED,
+  PERIPHERAL_IO_UNKNOWN_ERROR,
+};
+
+#endif  // SYSTEM_PERIPHERALMANAGER_ERRORS_H_
diff --git a/include/peripheralmanager/gpio.h b/include/peripheralmanager/gpio.h
new file mode 100644
index 0000000..883d15e
--- /dev/null
+++ b/include/peripheralmanager/gpio.h
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef SYSTEM_PERIPHERALMANAGER_GPIO_H_
+#define SYSTEM_PERIPHERALMANAGER_GPIO_H_
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+// Edge trigger types.
+enum {
+  NONE_EDGE,
+  RISING_EDGE,
+  FALLING_EDGE,
+  BOTH_EDGE,
+};
+
+// GPIO direction types.
+enum {
+  DIRECTION_IN,
+  DIRECTION_OUT_INITIALLY_HIGH,
+  DIRECTION_OUT_INITIALLY_LOW,
+};
+
+// Possible active types.
+enum {
+  ACTIVE_LOW,
+  ACTIVE_HIGH,
+};
+
+typedef struct BGpio BGpio;
+
+// Sets the GPIO direction to output.
+//
+// The physical initial value may be different from the logical value based
+// on the active low status
+//
+// Arguments:
+//    gpio: Pointer to the BGpio struct.
+//    direction: One of DIRECTION_IN, DIRECTION_OUT_INITIALLY_HIGH,
+//        DIRECTION_OUT_INITIALLY_LOW.
+//
+// Returns:
+//    Error code (one of peripheral_error_t).
+int BGpio_setDirection(const BGpio* gpio, int direction);
+
+// Sets the interrupt edge trigger type.
+//
+// Arguments:
+//    gpio: Pointer to the BGpio struct.
+//    type: One of NONE_EDGE, RISING_EDGE, FALLING_EDGE or BOTH_EDGE.
+//
+// Returns:
+//    Error code (one of peripheral_error_t).
+int BGpio_setEdgeTriggerType(const BGpio* gpio, int type);
+
+// Sets the GPIO’s active low/high status.
+//
+// Arguments:
+//    gpio: Pointer to the BGpio struct.
+//    type: One of ACTIVE_HIGH, ACTIVE_LOW.
+//
+// Returns:
+//    Error code (one of peripheral_error_t).
+int BGpio_setActiveType(const BGpio* gpio, int type);
+
+// Sets the GPIO value (for output GPIO only).
+//
+// Arguments:
+//    gpio: Pointer to the BGpio struct.
+//    value: Value to set.
+//
+// Returns:
+//    Error code (one of peripheral_error_t).
+int BGpio_setValue(const BGpio* gpio, int value);
+
+// Gets the GPIO value (for input GPIO only).
+//
+// Arguments:
+//    gpio: Pointer to the BGpio struct.
+//    value: Output pointer to the value of the GPIO.
+//
+// Returns:
+//    Error code (one of peripheral_error_t).
+int BGpio_getValue(const BGpio* gpio, int* value);
+
+// Returns a file descriptor that can be used to poll on new data.
+//
+// Can be passed to select/epoll to wait for data to become available.
+//
+// Arguments:
+//    gpio: Pointer to the BGpio struct.
+//    fd: Output pointer to the file descriptor number.
+//
+// Returns:
+//    Error code (one of peripheral_error_t).
+int BGpio_getPollFd(const BGpio* gpio, int* fd);
+
+// Destroys a BGpio struct.
+//
+// Arguments:
+//    gpio: Pointer to the BGpio struct.
+void BGpio_delete(BGpio* gpio);
+
+__END_DECLS
+
+#endif  // SYSTEM_PERIPHERALMANAGER_GPIO_H_
diff --git a/include/peripheralmanager/peripheral_manager_client.h b/include/peripheralmanager/peripheral_manager_client.h
index 9eabb8c..48273ca 100644
--- a/include/peripheralmanager/peripheral_manager_client.h
+++ b/include/peripheralmanager/peripheral_manager_client.h
@@ -17,34 +17,67 @@
 #ifndef SYSTEM_PERIPHERALMANAGER_PERIPHERAL_MANAGER_CLIENT_H_
 #define SYSTEM_PERIPHERALMANAGER_PERIPHERAL_MANAGER_CLIENT_H_
 
-#include <base/macros.h>
-#include <utils/StrongPointer.h>
+#include <sys/cdefs.h>
 
-namespace android {
+#include "peripheralmanager/errors.h"
+#include "peripheralmanager/gpio.h"
 
-namespace os {
-class IPeripheralManager;
-}
+__BEGIN_DECLS
 
-// Used to communicate with the peripheral manager.
-class PeripheralManagerClient {
- public:
-  PeripheralManagerClient();
-  ~PeripheralManagerClient();
+typedef struct BPeripheralManagerClient BPeripheralManagerClient;
 
-  // Initializes the object, returning true on success. Must be called before
-  // any other methods.
-  bool Init();
+// Returns the list of GPIOs.
+//
+// This does not take ownership into account.
+// The list must be freed by the caller.
+//
+// Arguments:
+//    client: Pointer to the BPeripheralManagerClient struct.
+//    num_gpio: Output pointer to the number of element in the list.
+//
+// Returns:
+//    The list of gpios.
+char** BPeripheralManagerClient_listGpio(const BPeripheralManagerClient* client,
+                                         int* num_gpio);
 
-  // Dummy method to test IPC
-  int AddInts(int a, int b);
+// Returns the list of available GPIOs.
+//
+// The list must be freed by the caller.
+//
+// Arguments:
+//    client: Pointer to the BPeripheralManagerClient struct.
+//    num_buses: Output pointer to the number of element in the list.
+//
+// Returns:
+//    The list of buses.
+char** BPeripheralManagerClient_listAvailableGpio(
+    const BPeripheralManagerClient* client, int* num_gpio);
 
- private:
-  sp<os::IPeripheralManager> pmanager_;
+// Opens a GPIO and takes ownership of it.
+//
+// Arguments:
+//    client: Pointer to the BPeripheralManagerClient struct.
+//    name: Name of the GPIO.
+//    gpio: Output pointer to the BGpio struct. Empty on error.
+//
+// Returns:
+//    Error code (one of peripheral_error_t).
+int BPeripheralManagerClient_openGpio(const BPeripheralManagerClient* client,
+                                      const char* name,
+                                      BGpio** gpio);
 
-  DISALLOW_COPY_AND_ASSIGN(PeripheralManagerClient);
-};
+// Creates a new client.
+//
+// Returns:
+//    A pointer to the created client. nullptr on errors.
+BPeripheralManagerClient* BPeripheralManagerClient_new();
 
-}  // namespace android
+// Destroys the peripheral manager client.
+//
+// Arguments:
+//    client: Pointer to the BPeripheralManagerClient struct.
+void BPeripheralManagerClient_delete(BPeripheralManagerClient* client);
+
+__END_DECLS
 
 #endif  //  SYSTEM_PERIPHERALMANAGER_PERIPHERAL_MANAGER_CLIENT_H_