Messages in this thread | | | Date | Sun, 16 Jul 2023 15:59:42 +0200 | From | Miquel Raynal <> | Subject | Re: [PATCH RESEND v5 1/3] ABI: sysfs-nvmem-cells: Expose cells through sysfs |
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Hi Randy,
rdunlap@infradead.org wrote on Thu, 13 Jul 2023 08:56:48 -0700:
> Hi, > > On 7/13/23 00:55, Miquel Raynal wrote: > > The binary content of nvmem devices is available to the user so in the > > easiest cases, finding the content of a cell is rather easy as it is > > just a matter of looking at a known and fixed offset. However, nvmem > > layouts have been recently introduced to cope with more advanced > > situations, where the offset and size of the cells is not known in > > advance or is dynamic. When using layouts, more advanced parsers are > > used by the kernel in order to give direct access to the content of each > > cell regardless of their position/size in the underlying device, but > > these information were not accessible to the user. > > > > By exposing the nvmem cells to the user through a dedicated cell/ folder > > containing one file per cell, we provide a straightforward access to > > useful user information without the need for re-writing a userland > > parser. Content of nvmem cells is usually: product names, manufacturing > > date, MAC addresses, etc, > > > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> > > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > > Documentation/ABI/testing/sysfs-nvmem-cells | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > create mode 100644 Documentation/ABI/testing/sysfs-nvmem-cells > > > > diff --git a/Documentation/ABI/testing/sysfs-nvmem-cells b/Documentation/ABI/testing/sysfs-nvmem-cells > > new file mode 100644 > > index 000000000000..641a7d7dad76 > > --- /dev/null > > +++ b/Documentation/ABI/testing/sysfs-nvmem-cells > > @@ -0,0 +1,19 @@ > > +What: /sys/bus/nvmem/devices/.../cells/<cell-name> > > +Date: May 2023 > > +KernelVersion: 6.5 > > +Contact: Miquel Raynal <miquel.raynal@bootlin.com> > > +Description: > > + The cells/ folder contains one file per cell exposed by > > (My shell doesn't show "folders". ;)
What do you mean? Is it your shell that needs fixing? Or is it something that I need to fix?
> > + the nvmem device. The name of the file is the cell name. > > + The length of the file is the size of the cell (when > > + known). The content of the file is the binary content of > > + the cell (may sometimes be ASCII, likely without > > + trailing character). > > + Note: This file is only present if CONFIG_NVMEM_SYSFS > > + is enabled > > add ending '.': enabled. > > > + > > + ex:: > > Example::
Yup, I'll fix it in v6.
> or > E.g.:: > > > + > > + hexdump -C /sys/bus/nvmem/devices/1-00563/cells/product-name > > + 00000000 54 4e 34 38 4d 2d 50 2d 44 4e |TN48M-P-DN| > > + 0000000a >
Thanks, Miquèl
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