spi_misc_test fail

为什么会fail，g_spi.0 is null，是因为dts配置错误，没有挂载驱动上去？

[root@localhost /]#
[root@localhost /]# echo read 0 10 255 > /dev/cspi_misc_test
[ 2232.193462] g_spi.0 is NULL
[ 2232.193742] g_spi.0 is NULL
[ 2232.194010] g_spi.0 is NULL
[ 2232.194276] g_spi.0 is NULL
[ 2232.194627] g_spi.0 is NULL
[ 2232.194893] g_spi.0 is NULL
[ 2232.195157] g_spi.0 is NULL
[ 2232.195443] g_spi.0 is NULL
[ 2232.195698] g_spi.0 is NULL
[ 2232.195962] g_spi.0 is NULL
[ 2232.196232] spi read 255*10 cost 2774us speed:919KB/S
[root@localhost /]#