AM335X SDK-PROCESSOR 3.02版本Pinmux以及devmem2问题

user4796556

想请教下2个问题

1.关于pinmux怎么通过devmem2读取状态，比如U14 pin脚，我配置成GPIO的话，需要设置成MODE7，这个怎么用devmem2把U14 pin设置成GPIO模式？

或则我用/sys/class/gpio配置成GPIO后，我怎么用devmem2判断我配置成功了。目前碰到个问题，调试SDIO WIFI的时候，MMC2的CLK pin和D3 pin 配置成输出后，拉高拉低，用/sys/class/gpio/gpioxx/value读出来正常，但是我们用示波器测量，高低无法被改变，所以我想通过devmem2知道这2个pin是否被正确配置。

2.为什么有些寄存器无法用devmem2读取，比如MMC2，其dts中的寄存器地址是0x481d8000,但是读取这个寄存器，会出现下面的错误，这个是为什么？

root@am335x-evm:~# devmem2 0x481d8000
/dev/mem opened.[ 282.075273] Unhandled fault: external abort on non-linefetch (0x1018) at 0xb6fc1000
[ 282.084187] pgd = dc724000
[ 282.086903] [b6fc1000] *pgd=9ab46831, *pte=481d8303, *ppte=481d8a33

Memory mapped at address 0xb6fc1000.
Bus error (core dumped)

8 年多前

0 Eggsy Pang 8 年多前

TI__Genius 9922 points

使用命令：

cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pins

来查看pinmux是否正确，如果不正确，如果使用PDK，修改DTB文件

0 user4796556 8 年多前回复 Eggsy Pang

Expert 1352 points

Eggsy，谢谢回复。有没有资料来理解打印出来的Pinmux什么意思？每一位各是什么功能。

root@am335x-evm:~# cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pins
registered pins: 142
pin 0 (44e10800.0) 00000030 pinctrl-single
pin 1 (44e10804.0) 00000030 pinctrl-single
pin 2 (44e10808.0) 00000030 pinctrl-single
pin 3 (44e1080c.0) 00000030 pinctrl-single
pin 4 (44e10810.0) 00000030 pinctrl-single
pin 5 (44e10814.0) 00000030 pinctrl-single
pin 6 (44e10818.0) 00000030 pinctrl-single
pin 7 (44e1081c.0) 00000030 pinctrl-single
pin 8 (44e10820.0) 00000009 pinctrl-single
pin 9 (44e10824.0) 00000009 pinctrl-single
pin 10 (44e10828.0) 00000009 pinctrl-single
pin 11 (44e1082c.0) 00000009 pinctrl-single
pin 12 (44e10830.0) 00000009 pinctrl-single
pin 13 (44e10834.0) 00000009 pinctrl-single
pin 14 (44e10838.0) 00000009 pinctrl-single
pin 15 (44e1083c.0) 00000009 pinctrl-single
pin 16 (44e10840.0) 00000027 pinctrl-single
pin 17 (44e10844.0) 00000033 pinctrl-single
pin 18 (44e10848.0) 00000033 pinctrl-single
pin 19 (44e1084c.0) 00000033 pinctrl-single
pin 20 (44e10850.0) 00000027 pinctrl-single
pin 21 (44e10854.0) 00000027 pinctrl-single
pin 22 (44e10858.0) 00000027 pinctrl-single
pin 23 (44e1085c.0) 00000027 pinctrl-single
pin 24 (44e10860.0) 00000027 pinctrl-single
pin 25 (44e10864.0) 00000027 pinctrl-single
pin 26 (44e10868.0) 00000027 pinctrl-single
pin 27 (44e1086c.0) 00000027 pinctrl-single
pin 28 (44e10870.0) 00000030 pinctrl-single
pin 29 (44e10874.0) 00000037 pinctrl-single
pin 30 (44e10878.0) 00000033 pinctrl-single
pin 31 (44e1087c.0) 00000008 pinctrl-single
pin 32 (44e10880.0) 00000037 pinctrl-single
pin 33 (44e10884.0) 00000037 pinctrl-single
pin 34 (44e10888.0) 00000033 pinctrl-single
pin 35 (44e1088c.0) 00000033 pinctrl-single
pin 36 (44e10890.0) 00000008 pinctrl-single
pin 37 (44e10894.0) 00000008 pinctrl-single
pin 38 (44e10898.0) 00000008 pinctrl-single
pin 39 (44e1089c.0) 00000008 pinctrl-single
pin 40 (44e108a0.0) 00000008 pinctrl-single
pin 41 (44e108a4.0) 00000008 pinctrl-single
pin 42 (44e108a8.0) 00000008 pinctrl-single
pin 43 (44e108ac.0) 00000008 pinctrl-single
pin 44 (44e108b0.0) 00000008 pinctrl-single
pin 45 (44e108b4.0) 00000008 pinctrl-single
pin 46 (44e108b8.0) 00000008 pinctrl-single
pin 47 (44e108bc.0) 00000008 pinctrl-single
pin 48 (44e108c0.0) 00000008 pinctrl-single
pin 49 (44e108c4.0) 00000008 pinctrl-single
pin 50 (44e108c8.0) 00000008 pinctrl-single
pin 51 (44e108cc.0) 00000008 pinctrl-single
pin 52 (44e108d0.0) 00000008 pinctrl-single
pin 53 (44e108d4.0) 00000008 pinctrl-single
pin 54 (44e108d8.0) 00000008 pinctrl-single
pin 55 (44e108dc.0) 00000008 pinctrl-single
pin 56 (44e108e0.0) 00000008 pinctrl-single
pin 57 (44e108e4.0) 00000008 pinctrl-single
pin 58 (44e108e8.0) 00000008 pinctrl-single
pin 59 (44e108ec.0) 00000008 pinctrl-single
pin 60 (44e108f0.0) 00000030 pinctrl-single
pin 61 (44e108f4.0) 00000030 pinctrl-single
pin 62 (44e108f8.0) 00000030 pinctrl-single
pin 63 (44e108fc.0) 00000030 pinctrl-single
pin 64 (44e10900.0) 00000030 pinctrl-single
pin 65 (44e10904.0) 00000030 pinctrl-single
pin 66 (44e10908.0) 00000027 pinctrl-single
pin 67 (44e1090c.0) 00000027 pinctrl-single
pin 68 (44e10910.0) 00000027 pinctrl-single
pin 69 (44e10914.0) 00000002 pinctrl-single
pin 70 (44e10918.0) 00000022 pinctrl-single
pin 71 (44e1091c.0) 00000002 pinctrl-single
pin 72 (44e10920.0) 00000002 pinctrl-single
pin 73 (44e10924.0) 00000002 pinctrl-single
pin 74 (44e10928.0) 00000002 pinctrl-single
pin 75 (44e1092c.0) 00000002 pinctrl-single
pin 76 (44e10930.0) 00000022 pinctrl-single
pin 77 (44e10934.0) 00000022 pinctrl-single
pin 78 (44e10938.0) 00000022 pinctrl-single
pin 79 (44e1093c.0) 00000022 pinctrl-single
pin 80 (44e10940.0) 00000022 pinctrl-single
pin 81 (44e10944.0) 00000027 pinctrl-single
pin 82 (44e10948.0) 00000030 pinctrl-single
pin 83 (44e1094c.0) 00000010 pinctrl-single
pin 84 (44e10950.0) 0000002a pinctrl-single
pin 85 (44e10954.0) 0000002a pinctrl-single
pin 86 (44e10958.0) 00000037 pinctrl-single
pin 87 (44e1095c.0) 00000037 pinctrl-single
pin 88 (44e10960.0) 00000029 pinctrl-single
pin 89 (44e10964.0) 00000009 pinctrl-single
pin 90 (44e10968.0) 0000000a pinctrl-single
pin 91 (44e1096c.0) 00000022 pinctrl-single
pin 92 (44e10970.0) 0000000a pinctrl-single
pin 93 (44e10974.0) 0000002a pinctrl-single
pin 94 (44e10978.0) 00000028 pinctrl-single
pin 95 (44e1097c.0) 00000000 pinctrl-single
pin 96 (44e10980.0) 00000030 pinctrl-single
pin 97 (44e10984.0) 00000000 pinctrl-single
pin 98 (44e10988.0) 00000030 pinctrl-single
pin 99 (44e1098c.0) 00000030 pinctrl-single
pin 100 (44e10990.0) 0000002f pinctrl-single
pin 101 (44e10994.0) 00000027 pinctrl-single
pin 102 (44e10998.0) 00000027 pinctrl-single
pin 103 (44e1099c.0) 0000000c pinctrl-single
pin 104 (44e109a0.0) 00000027 pinctrl-single
pin 105 (44e109a4.0) 00000027 pinctrl-single
pin 106 (44e109a8.0) 00000027 pinctrl-single
pin 107 (44e109ac.0) 00000027 pinctrl-single
pin 108 (44e109b0.0) 00000027 pinctrl-single
pin 109 (44e109b4.0) 00000003 pinctrl-single
pin 110 (44e109b8.0) 00000030 pinctrl-single
pin 111 (44e109bc.0) 00000028 pinctrl-single
pin 112 (44e109c0.0) 00000030 pinctrl-single
pin 113 (44e109c4.0) 00000028 pinctrl-single
pin 114 (44e109c8.0) 00000028 pinctrl-single
pin 115 (44e109cc.0) 00000028 pinctrl-single
pin 116 (44e109d0.0) 00000030 pinctrl-single
pin 117 (44e109d4.0) 00000030 pinctrl-single
pin 118 (44e109d8.0) 00000030 pinctrl-single
pin 119 (44e109dc.0) 00000030 pinctrl-single
pin 120 (44e109e0.0) 00000020 pinctrl-single
pin 121 (44e109e4.0) 00000030 pinctrl-single
pin 122 (44e109e8.0) 00000030 pinctrl-single
pin 123 (44e109ec.0) 00000028 pinctrl-single
pin 124 (44e109f0.0) 00000028 pinctrl-single
pin 125 (44e109f4.0) 00000028 pinctrl-single
pin 126 (44e109f8.0) 00000030 pinctrl-single
pin 127 (44e109fc.0) 00000028 pinctrl-single
pin 128 (44e10a00.0) 00000028 pinctrl-single
pin 129 (44e10a04.0) 00000020 pinctrl-single
pin 130 (44e10a08.0) 00000028 pinctrl-single
pin 131 (44e10a0c.0) 00000028 pinctrl-single
pin 132 (44e10a10.0) 00000028 pinctrl-single
pin 133 (44e10a14.0) 00000028 pinctrl-single
pin 134 (44e10a18.0) 00000028 pinctrl-single
pin 135 (44e10a1c.0) 00000020 pinctrl-single
pin 136 (44e10a20.0) 00000028 pinctrl-single
pin 137 (44e10a24.0) 00000028 pinctrl-single
pin 138 (44e10a28.0) 00000028 pinctrl-single
pin 139 (44e10a2c.0) 00000028 pinctrl-single
pin 140 (44e10a30.0) 00000028 pinctrl-single
pin 141 (44e10a34.0) 00000020 pinctrl-single