HOW TO ADD sound codes linux driver

1、由于我linux版本为4.14,所以想把高版本linux5.0 里的源码里 AK5558(==ADAU1977)的驱动(驱动时正常的)添加我目前用的linux源码里

2、我修改了sound/soc/codes/ 下 Kconfig  和 Makefile文件 ,改动如下:

kconfig 添加:

select SND_SOC_AK5558 if I2C

config SND_SOC_AK5558
         tristate "AKM AK5558 CODEC"
        depends on I2C
        select REGMAP_I2C

Makefile 添加:

snd-soc-ak5558-objs := ak5558.o

obj-$(CONFIG_SND_SOC_AK5558) += snd-soc-ak5558.o

然后menuconfig 配置好 选中 AK5558驱动选项,编译内核时出现

make[3]: *** No rule to make target 'sound/soc/codecs/ak5558.o', needed by 'sound/soc/codecs/snd-soc-ak5558.o'. Stop.
scripts/Makefile.build:573: recipe for target 'sound/soc/codecs' failed
make[2]: *** [sound/soc/codecs] Error 2
make[2]: *** Waiting for unfinished jobs....
scripts/Makefile.build:573: recipe for target 'sound/soc' failed
make[1]: *** [sound/soc] Error 2
Makefile:1024: recipe for target 'sound' failed
make: *** [sound] Error 2
make: *** Waiting for unfinished jobs....
AR kernel/built-in.o

这种现象应该是少修改了哪个地方?  是不是与  select REGMAP_I2C有关!谢谢了