TI中文支持网我们用am5726开发板在不接触摸屏的时候dmesg有如下信息root@am57xx-evm:~# dmesg |grep i2c
[ 0.553624] gpiochip_add: registered GPIOs 504 to 511 on device: 48070000.i2c
:tps659038@58:tps659038_gpio
[ 0.554034] omap_i2c 48070000.i2c: bus 0 rev0.12 at 400 kHz
[ 0.554538] omap_i2c 48060000.i2c: bus 2 rev0.12 at 400 kHz
[ 0.555111] omap_i2c 4807c000.i2c: bus 4 rev0.12 at 400 kHz
[ 1.800765] i2c /dev entries driver
[ 6.082145] of_get_named_gpiod_flags: can't parse 'gpio-reset' property of no
de '/ocp/i2c@48070000/tlv320aic3104@18[0]'
[ 6.263581] of_get_named_gpiod_flags: can't parse 'attb-gpios' property of no
de '/ocp/i2c@4807c000/pixcir_ts@5c[0]'
[ 6.263618] of_get_named_gpiod_flags: parsed 'attb-gpio' property of node '/o
cp/i2c@4807c000/pixcir_ts@5c[0]' – status (0)
[ 6.263657] of_get_named_gpiod_flags: can't parse 'reset-gpios' property of n
ode '/ocp/i2c@4807c000/pixcir_ts@5c[0]'
[ 6.263691] of_get_named_gpiod_flags: parsed 'reset-gpio' property of node '/
ocp/i2c@4807c000/pixcir_ts@5c[0]' – status (0)
[ 6.292526] rtc rtc1: 48070000.i2c:tps659: dev (254:1)
[ 6.292545] palmas-rtc 48070000.i2c:tps659038@58:tps659038_rtc: rtc core: reg
istered 48070000.i2c:tps659 as rtc1
[ 6.329956] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: GPIO lookup f
or consumer id
[ 6.329971] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: using devicetree for GPIO lookup
[ 6.329984] of_get_named_gpiod_flags: can't parse 'id-gpios' property of node
'/ocp/i2c@48070000/tps659038@58/tps659038_usb[0]'
[ 6.329994] of_get_named_gpiod_flags: can't parse 'id-gpio' property of node'/ocp/i2c@48070000/tps659038@58/tps659038_usb[0]'
[ 6.330003] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: using lookuptables for GPIO lookup
[ 6.330014] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: lookup for GP
IO id failed
[ 6.330023] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: GPIO lookup f
or consumer vbus
[ 6.330032] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: using devicetree for GPIO lookup
[ 6.330041] of_get_named_gpiod_flags: can't parse 'vbus-gpios' property of no
de '/ocp/i2c@48070000/tps659038@58/tps659038_usb[0]'
[ 6.330097] of_get_named_gpiod_flags: parsed 'vbus-gpio' property of node '/o
cp/i2c@48070000/tps659038@58/tps659038_usb[0]' – status (0)
[ 6.546022] of_get_named_gpiod_flags: parsed 'reset-gpios' property of node '
/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
[ 6.546081] of_get_named_gpiod_flags: parsed 'powerdown-gpios' property of no
de '/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
[ 6.546131] of_get_named_gpiod_flags: parsed 'oscen-gpios' property of node '
/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
[ 6.546181] of_get_named_gpiod_flags: parsed 'bufen-gpios' property of node '
/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
[ 6.546231] of_get_named_gpiod_flags: parsed 'camen-gpios' property of node '
/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
我们自己设计的版卡root@am57xx-evm:~# dmesg |grep i2c
[ 0.553624] gpiochip_add: registered GPIOs 504 to 511 on device: 48070000.i2c
:tps659038@58:tps659038_gpio
[ 0.554034] omap_i2c 48070000.i2c: bus 0 rev0.12 at 400 kHz
[ 0.554538] omap_i2c 48060000.i2c: bus 2 rev0.12 at 400 kHz
[ 1.800765] i2c /dev entries driver
[ 6.082145] of_get_named_gpiod_flags: can't parse 'gpio-reset' property of no
de '/ocp/i2c@48070000/tlv320aic3104@18[0]'
[ 6.292526] rtc rtc1: 48070000.i2c:tps659: dev (254:1)
[ 6.292545] palmas-rtc 48070000.i2c:tps659038@58:tps659038_rtc: rtc core: reg
istered 48070000.i2c:tps659 as rtc1
[ 6.329956] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: GPIO lookup f
or consumer id
[ 6.329971] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: using devicetree for GPIO lookup
[ 6.329984] of_get_named_gpiod_flags: can't parse 'id-gpios' property of node
'/ocp/i2c@48070000/tps659038@58/tps659038_usb[0]'
[ 6.329994] of_get_named_gpiod_flags: can't parse 'id-gpio' property of node'/ocp/i2c@48070000/tps659038@58/tps659038_usb[0]'
[ 6.330003] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: using lookuptables for GPIO lookup
[ 6.330014] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: lookup for GP
IO id failed
[ 6.330023] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: GPIO lookup f
or consumer vbus
[ 6.330032] palmas-usb 48070000.i2c:tps659038@58:tps659038_usb: using devicetree for GPIO lookup
[ 6.330041] of_get_named_gpiod_flags: can't parse 'vbus-gpios' property of no
de '/ocp/i2c@48070000/tps659038@58/tps659038_usb[0]'
[ 6.330097] of_get_named_gpiod_flags: parsed 'vbus-gpio' property of node '/o
cp/i2c@48070000/tps659038@58/tps659038_usb[0]' – status (0)
[ 6.546022] of_get_named_gpiod_flags: parsed 'reset-gpios' property of node '
/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
[ 6.546081] of_get_named_gpiod_flags: parsed 'powerdown-gpios' property of no
de '/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
[ 6.546131] of_get_named_gpiod_flags: parsed 'oscen-gpios' property of node '
/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
[ 6.546181] of_get_named_gpiod_flags: parsed 'bufen-gpios' property of node '
/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
[ 6.546231] of_get_named_gpiod_flags: parsed 'camen-gpios' property of node '
/ocp/i2c@4807c000/mt9t11x@3C[0]' – status (0)
同样的内核为什么开发板可以检测到omap_i2c 4807c000.i2c: bus 4 rev0.12 at 400 kHz
而我们的版卡却没有这句打印，硬件设计也一样和开发板一样触摸屏接在i2c5上，谢谢ti工程师们的解答！
Jian Zhou：
你们的板子上，内核没有检测到I2C设备么？
lu Cao2：
回复 Jian Zhou:
谢谢您的回答 我倒是解决了 不过很疑惑 我在设备树下am57xx-beagle-x15.dtb添加了i2c5，就可以检测到i2c5了，但是开发板也没有添加也可以检测到啊，为什么我们自己的板子需要添加一下
