| Message ID | 20180810080526.27207-3-brgl@bgdev.pl |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | at24: remove at24_platform_data | expand |
On Fri, Aug 10, 2018 at 10:04:59AM +0200, Bartosz Golaszewski wrote: > From: Bartosz Golaszewski <bgolaszewski@baylibre.com> > > Describe the usage of nvmem cell lookup tables. > > Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> > --- > Documentation/nvmem/nvmem.txt | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/Documentation/nvmem/nvmem.txt b/Documentation/nvmem/nvmem.txt > index 8d8d8f58f96f..9d5e3ca2b4f3 100644 > --- a/Documentation/nvmem/nvmem.txt > +++ b/Documentation/nvmem/nvmem.txt > @@ -58,6 +58,34 @@ static int qfprom_probe(struct platform_device *pdev) > It is mandatory that the NVMEM provider has a regmap associated with its > struct device. Failure to do would return error code from nvmem_register(). > > +Additionally it is possible to create nvmem cell lookup entries and register > +them with the nvmem framework from machine code as shown in the example below: Maybe it's partially a lacking in the existing documentation, but what does the "name" and the "nvmem_name" mean here? AFAICT, "nvmem_name" is akin to a provider identifier; and "name" is a key to match with the consumer. It feels like this should be in either the header / kerneldoc or this file. Or maybe both. Does this mean there can only be a single "mac-address" cell in the system? I have systems where there are multiple MACs provided in flash storage, and we need to map them to ethernet0 and ethernet1. Is that supported here? Brian > +static struct nvmem_cell_lookup foobar_lookup = { > + .info = { > + .name = "mac-address", > + .offset = 0xd000, > + .bytes = ERH_ALEN, > + }, > + .nvmem_name = "foobar", > +}; > + > +static void foobar_register(void) > +{ > + ... > + nvmem_add_lookup_table(&foobar_lookup, 1); > + ... > +} > + > +A lookup entry table can be later removed if needed: > + > +static void foobar_fini(void) > +{ > + ... > + nvmem_del_lookup_table(&foobar_lookup, 1); > + ... > +} > + > NVMEM Consumers > +++++++++++++++ > > -- > 2.18.0 >
2018-08-31 22:30 GMT+02:00 Brian Norris <computersforpeace@gmail.com>: > On Fri, Aug 10, 2018 at 10:04:59AM +0200, Bartosz Golaszewski wrote: >> From: Bartosz Golaszewski <bgolaszewski@baylibre.com> >> >> Describe the usage of nvmem cell lookup tables. >> >> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> >> --- >> Documentation/nvmem/nvmem.txt | 28 ++++++++++++++++++++++++++++ >> 1 file changed, 28 insertions(+) >> >> diff --git a/Documentation/nvmem/nvmem.txt b/Documentation/nvmem/nvmem.txt >> index 8d8d8f58f96f..9d5e3ca2b4f3 100644 >> --- a/Documentation/nvmem/nvmem.txt >> +++ b/Documentation/nvmem/nvmem.txt >> @@ -58,6 +58,34 @@ static int qfprom_probe(struct platform_device *pdev) >> It is mandatory that the NVMEM provider has a regmap associated with its >> struct device. Failure to do would return error code from nvmem_register(). >> >> +Additionally it is possible to create nvmem cell lookup entries and register >> +them with the nvmem framework from machine code as shown in the example below: > > Maybe it's partially a lacking in the existing documentation, but what > does the "name" and the "nvmem_name" mean here? AFAICT, "nvmem_name" is > akin to a provider identifier; and "name" is a key to match with the > consumer. It feels like this should be in either the header / kerneldoc > or this file. Or maybe both. > > Does this mean there can only be a single "mac-address" cell in the > system? I have systems where there are multiple MACs provided in flash > storage, and we need to map them to ethernet0 and ethernet1. Is that > supported here? > This is a shortcoming of the nvmem subsystem we discussed under another patch in this series with Boris and Srinivas. I will try to post a series addressing this next week. Basically there's a global list of nvmem cells referenced only by name and unless you're using DT you can only have a single cell with given name. I will address it by introducing the standard dev_id/con_id resource association. Bart > Brian > >> +static struct nvmem_cell_lookup foobar_lookup = { >> + .info = { >> + .name = "mac-address", >> + .offset = 0xd000, >> + .bytes = ERH_ALEN, >> + }, >> + .nvmem_name = "foobar", >> +}; >> + >> +static void foobar_register(void) >> +{ >> + ... >> + nvmem_add_lookup_table(&foobar_lookup, 1); >> + ... >> +} >> + >> +A lookup entry table can be later removed if needed: >> + >> +static void foobar_fini(void) >> +{ >> + ... >> + nvmem_del_lookup_table(&foobar_lookup, 1); >> + ... >> +} >> + >> NVMEM Consumers >> +++++++++++++++ >> >> -- >> 2.18.0 >>
diff --git a/Documentation/nvmem/nvmem.txt b/Documentation/nvmem/nvmem.txt index 8d8d8f58f96f..9d5e3ca2b4f3 100644 --- a/Documentation/nvmem/nvmem.txt +++ b/Documentation/nvmem/nvmem.txt @@ -58,6 +58,34 @@ static int qfprom_probe(struct platform_device *pdev) It is mandatory that the NVMEM provider has a regmap associated with its struct device. Failure to do would return error code from nvmem_register(). +Additionally it is possible to create nvmem cell lookup entries and register +them with the nvmem framework from machine code as shown in the example below: + +static struct nvmem_cell_lookup foobar_lookup = { + .info = { + .name = "mac-address", + .offset = 0xd000, + .bytes = ERH_ALEN, + }, + .nvmem_name = "foobar", +}; + +static void foobar_register(void) +{ + ... + nvmem_add_lookup_table(&foobar_lookup, 1); + ... +} + +A lookup entry table can be later removed if needed: + +static void foobar_fini(void) +{ + ... + nvmem_del_lookup_table(&foobar_lookup, 1); + ... +} + NVMEM Consumers +++++++++++++++