判断I2C总线设备是否存在，每次都去查dmesg，实在是烦了，于是还是移植一个i2c-tools比较好，不用翻那长长内核信息。
/**************************************************************************
* I.MX6 Android i2c-tools porting
* 说明：
* 判断I2C总线设备是否存在，每次都去查dmesg，实在是烦了，于是还是移植
* 一个i2c-tools比较好，不用翻那长长内核信息。
*
* 2016-3-31 深圳 南山平山村 曾剑锋
*************************************************************************/
一、参考资料：
1. Android 平台下使用 i2c-tools
http://my.oschina.net/luoly/blog/368881
2. 树莓派学习笔记——I2C Tools 学习笔记
http://blog.csdn.net/xukai871105/article/details/15029843
3. Linux I2C工具查看配置I2C设备
http://blog.chinaunix.net/uid-26895763-id-3478882.html
二、download:
groeck/i2c-tools:
https://github.com/groeck/i2c-tools
三、Decompress：
zengjf@zengjf:~$ unzip i2c-tools-master.zip
zengjf@zengjf:~$ mv i2c-tools-master ~/myandroid/external/i2c-tools/
四、cat external/i2c-tools/Android.mk
# external/i2c-tools/Android.mk
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE_TAGS := eng
LOCAL_C_INCLUDES += $(LOCAL_PATH) $(LOCAL_PATH)/$(KERNEL_DIR)/include
LOCAL_SRC_FILES :=tools/util.c tools/i2cbusses.c
LOCAL_MODULE := i2c-tools
include $(BUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE_TAGS := eng
LOCAL_SRC_FILES:=tools/i2cdetect.c
LOCAL_MODULE:=i2cdetect
LOCAL_CPPFLAGS += -DANDROID
LOCAL_SHARED_LIBRARIES:=libc
LOCAL_STATIC_LIBRARIES := i2c-tools
LOCAL_C_INCLUDES += $(LOCAL_PATH) $(LOCAL_PATH)/$(KERNEL_DIR)/include
include $(BUILD_EXECUTABLE)
include $(CLEAR_VARS)
LOCAL_MODULE_TAGS := eng
LOCAL_SRC_FILES:=tools/i2cget.c
LOCAL_MODULE:=i2cget
LOCAL_CPPFLAGS += -DANDROID
LOCAL_SHARED_LIBRARIES:=libc
LOCAL_STATIC_LIBRARIES := i2c-tools
LOCAL_C_INCLUDES += $(LOCAL_PATH) $(LOCAL_PATH)/$(KERNEL_DIR)/include
include $(BUILD_EXECUTABLE)
include $(CLEAR_VARS)
LOCAL_MODULE_TAGS := eng
LOCAL_SRC_FILES:=tools/i2cset.c
LOCAL_MODULE:=i2cset
LOCAL_CPPFLAGS += -DANDROID
LOCAL_SHARED_LIBRARIES:=libc
LOCAL_STATIC_LIBRARIES := i2c-tools
LOCAL_C_INCLUDES += $(LOCAL_PATH) $(LOCAL_PATH)/$(KERNEL_DIR)/include
include $(BUILD_EXECUTABLE)
include $(CLEAR_VARS)
LOCAL_MODULE_TAGS := eng
LOCAL_SRC_FILES:=tools/i2cdump.c
LOCAL_MODULE:=i2cdump
LOCAL_CPPFLAGS += -DANDROID
LOCAL_SHARED_LIBRARIES:=libc
LOCAL_STATIC_LIBRARIES := i2c-tools
LOCAL_C_INCLUDES += $(LOCAL_PATH) $(LOCAL_PATH)/$(KERNEL_DIR)/include
include $(BUILD_EXECUTABLE)
五、compile error:
1. 现象：
......
PRODUCT_COPY_FILES frameworks/base/data/sounds/ringtones/ogg/Solarium.ogg:system/media/audio/ringtones/Solarium.ogg ignored.
No private recovery resources for TARGET_DEVICE sabresd_6dq
make: Entering directory `/home/zengjf/myandroid'
target thumb C: i2c-tools <= /home/zengjf/myandroid/external/i2c-tools//lib/smbus.c
target StaticLib: i2c-tools (out/target/product/sabresd_6dq/obj/STATIC_LIBRARIES/i2c-tools_intermediates/i2c-tools.a)
target thumb C: i2cdetect <= /home/zengjf/myandroid/external/i2c-tools/lib/smbus.c
target thumb C: i2cdetect <= /home/zengjf/myandroid/external/i2c-tools/tools/i2cdetect.c
/home/zengjf/myandroid/external/i2c-tools/tools/i2cdetect.c:157:13: error: 'I2C_FUNC_SMBUS_PEC' undeclared here (not in a function)
make: *** [out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cdetect_intermediates/tools/i2cdetect.o] Error 1
make: Leaving directory `/home/zengjf/myandroid'
2. 解决办法：
cat external/i2c-tools/include/i2c/smbus.h
.....
/* Compatibility defines 添加宏声明*/
#ifndef I2C_SMBUS_I2C_BLOCK_BROKEN
#define I2C_SMBUS_I2C_BLOCK_BROKEN I2C_SMBUS_I2C_BLOCK_DATA
#endif
#ifndef I2C_FUNC_SMBUS_PEC
#define I2C_FUNC_SMBUS_PEC I2C_FUNC_SMBUS_HWPEC_CALC
#endif
extern __s32 i2c_smbus_access(int file, char read_write, __u8 command,
int size, union i2c_smbus_data *data);
extern __s32 i2c_smbus_write_quick(int file, __u8 value);
......
3. 正常现象：
No private recovery resources for TARGET_DEVICE sabresd_6dq
make: Entering directory `/home/zengjf/myandroid'
target thumb C: i2cdetect <= /home/zengjf/myandroid/external/i2c-tools/tools/i2cdetect.c
target Executable: i2cdetect (out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cdetect_intermediates/LINKED/i2cdetect)
target Symbolic: i2cdetect (out/target/product/sabresd_6dq/symbols/system/bin/i2cdetect)
Export includes file: /home/zengjf/myandroid/external/i2c-tools/Android.mk -- out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cdetect_intermediates/export_includes
target Strip: i2cdetect (out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cdetect_intermediates/i2cdetect)
Install: out/target/product/sabresd_6dq/system/bin/i2cdetect
Import includes file: out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cget_intermediates/import_includes
target thumb C: i2cget <= /home/zengjf/myandroid/external/i2c-tools/tools/i2cget.c
target Executable: i2cget (out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cget_intermediates/LINKED/i2cget)
target Symbolic: i2cget (out/target/product/sabresd_6dq/symbols/system/bin/i2cget)
Export includes file: /home/zengjf/myandroid/external/i2c-tools/Android.mk -- out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cget_intermediates/export_includes
target Strip: i2cget (out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cget_intermediates/i2cget)
Install: out/target/product/sabresd_6dq/system/bin/i2cget
Import includes file: out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cset_intermediates/import_includes
target thumb C: i2cset <= /home/zengjf/myandroid/external/i2c-tools/tools/i2cset.c
target Executable: i2cset (out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cset_intermediates/LINKED/i2cset)
target Symbolic: i2cset (out/target/product/sabresd_6dq/symbols/system/bin/i2cset)
Export includes file: /home/zengjf/myandroid/external/i2c-tools/Android.mk -- out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cset_intermediates/export_includes
target Strip: i2cset (out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cset_intermediates/i2cset)
Install: out/target/product/sabresd_6dq/system/bin/i2cset
Import includes file: out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cdump_intermediates/import_includes
target thumb C: i2cdump <= /home/zengjf/myandroid/external/i2c-tools/tools/i2cdump.c
target Executable: i2cdump (out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cdump_intermediates/LINKED/i2cdump)
target Symbolic: i2cdump (out/target/product/sabresd_6dq/symbols/system/bin/i2cdump)
Export includes file: /home/zengjf/myandroid/external/i2c-tools/Android.mk -- out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cdump_intermediates/export_includes
target Strip: i2cdump (out/target/product/sabresd_6dq/obj/EXECUTABLES/i2cdump_intermediates/i2cdump)
Install: out/target/product/sabresd_6dq/system/bin/i2cdump
make: Leaving directory `/home/zengjf/myandroid'
zengjf@zengjf:~/myandroid$
4. adb push <编译出来的可执行程序> /data/local
六、i2cdetect test:
1. test1:
1|root@android:/data/local # ./i2cdetect -l
i2c-3 i2c i2c-gpio3 I2C adapter
i2c-0 i2c imx-i2c I2C adapter
i2c-1 i2c imx-i2c I2C adapter
i2c-2 i2c imx-i2c I2C adapter
root@android:/data/local #
2. test2:
root@android:/data/local # ./i2cdetect -y -r 2
1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: UU -- -- -- -- UU -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
七、i2cget test:
1|root@android:/data/local # ./i2cget -y 1 0x08 0x03
Error: Could not set address to 0x08: Device or resource busy
1|root@android:/data/local # ./i2cget -f -y 1 0x08 0x03
0x21
1|root@android:/data/local #
