On 24/06/15 13:30, Stefan Wahren wrote:

quoted

quoted

If the question is just about hexdump, then hexdump itself can read
file from given offset and size.

yes, this is my question at first. Let me show the difference between
the current implementation and my expectations as a user.

$ hexdump /sys/class/nvmem/mxs-ocotp/nvmem

Current implementation: dump the complete register range defined in DT

Its dumping the range which is specified in the provider regmap. If the 
requirement is to dump only particular range, this has to be made 
explicit while creating regmap, which is to specify the base address to 
start from "First data register" and max_register to be "Last data 
register "- "First data register"

User expectation: dump only the data from OCOTP block

Let me explain it for i.MX28 OCOTP

0x8002c000 // Start of OCOTP register block (defined in DT)

0x8002c020 // First data register

0x8002c290 // Last data register

0x8002dfff // End of OCOTP register block (defined in DT)

My knowledge about regmap is limited, but how can i achieve that hexdump
give me only the data registers? From my understanding this should be
handled in regmap and not in the read function.

Setup the base and regmap_config correctly in the provider driver before 
calling regmap_init_mmio().

Let me know if you need more details.

--srini

Are my expectations about the raw access wrong?