On 6/1/24 03:41, Thomas Weißschuh wrote:
On 2024-05-31 22:42:24+0000, Guenter Roeck wrote:
On 5/31/24 16:05, Guenter Roeck wrote:
Add support for reading SPD NVRAM data from SPD5118 (Jedec JESD300)
compliant memory modules. NVRAM write operation is not supported.
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
v3: New patch
RFT: I'd like to get some more test coverage before moving forward
with this patch. decode-dimms doesn't recognize the 'spd5118'
driver.
Looks good to me.
Spot-checking against JSED400-5B and the embedded CRC are as expected.
Looking for feedback:
[ ... ]
+
+ nvmem = devm_nvmem_register(dev, &nvmem_config);
This returns ERR_PTR(-EOPNOTSUPP) if CONFIG_NVRAM=n. We have two options:
- Ignore -EOPNOTSUPP and continue registering the hwmon device
or
- Add
select NVRAM
select NVRAM_SYSFS
to the driver's Kconfig entry.
s/NVRAM/NVMEM/g
Any preferences ?
It seems reasonable to support the module without the eeprom logic.
When used in a fixed, embedded environment, the eeprom is of limited
value as it's known beforehand, while the hwmon functionality is still
useful.
Makes sense. Another question:
This:
+ struct nvmem_config nvmem_config = {
+ .type = NVMEM_TYPE_EEPROM,
+ .name = dev_name(dev),
+ .id = NVMEM_DEVID_AUTO,
results in:
$ ls /sys/bus/nvmem/devices
0-00501 0-00512 0-00523 0-00534 cmos_nvram0
^^^^^^^ ^^^^^^^ ^^^^^^^ ^^^^^^^
which really doesn't look good. My current plan is to go with NVMEM_DEVID_NONE,
which results in
$ ls /sys/bus/nvmem/devices
0-0050 0-0051 0-0052 0-0053 cmos_nvram0
We could also used fixed strings, but "spd" results in "spd[1-4]" which
I think would be a bit misleading since the DDR3/4 SPD data format is
different, and "spd5118" would result in "spd5118[1-4]" which again would
look odd. Any suggestions ?
Thanks,
Guenter
