i9300: add GPS shim

* AGpsRefLocation changed size between M and N, causing AGPS to
explode. Fix this by passing our own, M version of the struct and
translating between the two ABIs.

Change-Id: Ic755dbcf842fa9e6f928d384a0c504d10656ee9b

6 files changed, 220 insertions, 1 deletions

diff --git a/i9300.mk b/i9300.mk
index b00b0a8..b10b7e9 100644
--- a/i9300.mk
+++ b/i9300.mk
@@ -45,6 +45,9 @@ PRODUCT_COPY_FILES += \
     $(LOCAL_PATH)/configs/gps.xml:system/etc/gps.xml \
     $(LOCAL_PATH)/gps_daemon.sh:system/bin/gps_daemon.sh
 
+PRODUCT_PACKAGES += \
+	gps.smdk4x12
+
 # Keylayout
 PRODUCT_COPY_FILES += \
     $(LOCAL_PATH)/keylayout/sec_touchkey.kl:system/usr/keylayout/sec_touchkey.kl
diff --git a/proprietary-files.txt b/proprietary-files.txt
index 027777e..bc71c03 100644
--- a/proprietary-files.txt
+++ b/proprietary-files.txt
@@ -1,4 +1,4 @@
 system/bin/glgps
-system/lib/hw/gps.exynos4.so:system/lib/hw/gps.tegra3.so
+system/lib/hw/gps.exynos4.vendor.so:system/lib/hw/gps.tegra3.so
 system/lib/libakm.so
 system/lib/libsec-ril.so
diff --git a/shims/Android.mk b/shims/Android.mk
new file mode 100644
index 0000000..07abb16
--- /dev/null
+++ b/shims/Android.mk
@@ -0,0 +1,17 @@
+# Copyright (C) 2016 The CyanogenMod 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 $(call all-makefiles-under, $(LOCAL_PATH))
diff --git a/shims/libgps-shim/Android.mk b/shims/libgps-shim/Android.mk
new file mode 100644
index 0000000..cfcedb2
--- /dev/null
+++ b/shims/libgps-shim/Android.mk
@@ -0,0 +1,28 @@
+# Copyright (C) 2016 The CyanogenMod 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 $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := gps.c
+
+LOCAL_SHARED_LIBRARIES := \
+	libcutils \
+	liblog
+
+LOCAL_MODULE := gps.$(TARGET_BOOTLOADER_BOARD_NAME)
+LOCAL_MODULE_RELATIVE_PATH := hw
+
+include $(BUILD_SHARED_LIBRARY)
diff --git a/shims/libgps-shim/gps.c b/shims/libgps-shim/gps.c
new file mode 100644
index 0000000..1b1a19d
--- /dev/null
+++ b/shims/libgps-shim/gps.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project <http://www.cyanogenmod.org>
+ *
+ * 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.
+ */
+#define LOG_TAG "libgps-shim"
+
+#include <utils/Log.h>
+#include <hardware/gps.h>
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "gps.h"
+#define REAL_GPS_PATH "/system/lib/hw/gps.exynos4.vendor.so"
+
+const GpsInterface* (*vendor_get_gps_interface)(struct gps_device_t* dev);
+const void* (*vendor_get_extension)(const char* name);
+void (*vendor_set_ref_location)(const AGpsRefLocationNoLTE *agps_reflocation, size_t sz_struct);
+
+void shim_set_ref_location(const AGpsRefLocation *agps_reflocation, size_t sz_struct) {
+	// this is mildly ugly
+	AGpsRefLocationNoLTE vendor_ref;
+	if (sizeof(AGpsRefLocationNoLTE) < sz_struct) {
+		ALOGE("%s: AGpsRefLocation is too small, bailing out!", __func__);
+		return;
+	}
+	ALOGE("%s: shimming AGpsRefLocation", __func__);
+	// the two structs are identical, so this is ok
+	memcpy(&vendor_ref, agps_reflocation, sizeof(AGpsRefLocationNoLTE));
+	vendor_set_ref_location(&vendor_ref, sizeof(AGpsRefLocationNoLTE));
+	// copy it back
+	memcpy(agps_reflocation, &vendor_ref, sizeof(AGpsRefLocationNoLTE));
+}
+
+const void* shim_get_extension(const char* name) {
+	ALOGE("%s(%s)", __func__, name);
+	if (strcmp(name, AGPS_RIL_INTERFACE) == 0) {
+		// RIL interface
+		AGpsRilInterface *ril = (AGpsRilInterface*)vendor_get_extension(name);
+		// now we shim the ref_location callback
+		ALOGE("%s: shimming RIL ref_location callback", __func__);
+		vendor_set_ref_location = ril->set_ref_location;
+		ril->set_ref_location = shim_set_ref_location;
+		return ril;
+	} else {
+		return vendor_get_extension(name);
+	}
+}
+
+const GpsInterface* shim_get_gps_interface(struct gps_device_t* dev) {
+	ALOGE("%s: shimming vendor get_extension", __func__);
+	GpsInterface *halInterface = vendor_get_gps_interface(dev);
+
+	vendor_get_extension = halInterface->get_extension;
+	halInterface->get_extension = &shim_get_extension;
+
+	return halInterface;
+}
+
+static int open_gps(const struct hw_module_t* module, char const* name,
+		struct hw_device_t** device) {
+	void *realGpsLib;
+	int gpsHalResult;
+	struct hw_module_t *realHalSym;
+
+	struct gps_device_t **gps = (struct gps_device_t **)device;
+
+	realGpsLib = dlopen(REAL_GPS_PATH, RTLD_LOCAL);
+	if (!realGpsLib) {
+		ALOGE("Failed to load real GPS HAL '" REAL_GPS_PATH "': %s", dlerror());
+		return -EINVAL;
+	}
+
+	realHalSym = (struct hw_module_t*)dlsym(realGpsLib, HAL_MODULE_INFO_SYM_AS_STR);
+	if (!realHalSym) {
+		ALOGE("Failed to locate the GPS HAL module sym: '" HAL_MODULE_INFO_SYM_AS_STR "': %s", dlerror());
+		goto dl_err;
+	}
+
+	int result = realHalSym->methods->open(realHalSym, name, device);
+	if (result < 0) {
+		ALOGE("Real GPS open method failed: %d", result);
+		goto dl_err;
+	}
+	ALOGE("Successfully loaded real GPS hal, shimming get_gps_interface...");
+	// now, we shim hw_device_t
+	vendor_get_gps_interface = (*gps)->get_gps_interface;
+	(*gps)->get_gps_interface = &shim_get_gps_interface;
+
+	return 0;
+dl_err:
+	dlclose(realGpsLib);
+	return -EINVAL;
+}
+
+static struct hw_module_methods_t gps_module_methods = {
+	.open = open_gps
+};
+
+struct hw_module_t HAL_MODULE_INFO_SYM = {
+	.tag = HARDWARE_MODULE_TAG,
+	.module_api_version = 1,
+	.hal_api_version = 0,
+	.id = GPS_HARDWARE_MODULE_ID,
+	.name = "BCM451x GPS shim",
+	.author = "The CyanogenMod Project",
+	.methods = &gps_module_methods
+};
diff --git a/shims/libgps-shim/gps.h b/shims/libgps-shim/gps.h
new file mode 100644
index 0000000..591f464
--- /dev/null
+++ b/shims/libgps-shim/gps.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project <http://www.cyanogenmod.org>
+ *
+ * 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 <hardware/gps.h>
+
+/* CellID for 2G, 3G and LTE, used in AGPS. */
+typedef struct {
+    AGpsRefLocationType type;
+    /** Mobile Country Code. */
+    uint16_t mcc;
+    /** Mobile Network Code .*/
+    uint16_t mnc;
+    /** Location Area Code in 2G, 3G and LTE. In 3G lac is discarded. In LTE,
+     * lac is populated with tac, to ensure that we don't break old clients that
+     * might rely in the old (wrong) behavior.
+     */
+    uint16_t lac;
+    /** Cell id in 2G. Utran Cell id in 3G. Cell Global Id EUTRA in LTE. */
+    uint32_t cid;
+#if 0 // introduced in N.
+    /** Tracking Area Code in LTE. */
+    uint16_t tac;
+    /** Physical Cell id in LTE (not used in 2G and 3G) */
+    uint16_t pcid;
+#endif
+} AGpsRefLocationCellIDNoLTE;
+
+/** Represents ref locations */
+typedef struct {
+    AGpsRefLocationType type;
+    union {
+        AGpsRefLocationCellIDNoLTE	cellID;
+		AGpsRefLocationMac			mac;
+    } u;
+} AGpsRefLocationNoLTE;
+
+