pi@raspberrypi:~ $ udevadm info -a -n /dev/mmcblk0
Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.
looking at device '/devices/platform/soc/3f202000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0':
KERNEL=="mmcblk0"
SUBSYSTEM=="block"
DRIVER==""
ATTR{alignment_offset}=="0"
ATTR{capability}=="50"
ATTR{discard_alignment}=="0"
ATTR{ext_range}=="256"
ATTR{force_ro}=="0"
ATTR{inflight}==" 0 0"
ATTR{range}=="32"
ATTR{removable}=="0"
ATTR{ro}=="0"
ATTR{size}=="62521344"
ATTR{stat}==" 369 14985 19483 1090 2 0 2 0 0 550 1090"
looking at parent device '/devices/platform/soc/3f202000.mmc/mmc_host/mmc0/mmc0:0001':
KERNELS=="mmc0:0001"
SUBSYSTEMS=="mmc"
DRIVERS=="mmcblk"
ATTRS{cid}=="5d53424c32424d31013917ca53010459"
ATTRS{csd}=="400e00325b590000ee7f7f800a405067"
ATTRS{date}=="04/2016"
ATTRS{dsr}=="0x404"
ATTRS{erase_size}=="512"
ATTRS{fwrev}=="0x1"
ATTRS{hwrev}=="0x0"
ATTRS{manfid}=="0x00005d"
ATTRS{name}=="L2BM1"
ATTRS{ocr}=="0x00200000"
ATTRS{oemid}=="0x5342"
ATTRS{preferred_erase_size}=="4194304"
ATTRS{scr}=="02b5800200000000"
ATTRS{serial}=="0x3917ca53"
ATTRS{ssr}=="00000000050000000400900000011c00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
ATTRS{type}=="SD"
looking at parent device '/devices/platform/soc/3f202000.mmc/mmc_host/mmc0':
KERNELS=="mmc0"
SUBSYSTEMS=="mmc_host"
DRIVERS==""
looking at parent device '/devices/platform/soc/3f202000.mmc':
KERNELS=="3f202000.mmc"
SUBSYSTEMS=="platform"
DRIVERS=="sdhost-bcm2835"
ATTRS{driver_override}=="(null)"
looking at parent device '/devices/platform/soc':
KERNELS=="soc"
SUBSYSTEMS=="platform"
DRIVERS==""
ATTRS{driver_override}=="(null)"
looking at parent device '/devices/platform':
KERNELS=="platform"
SUBSYSTEMS==""
DRIVERS==""