Re: [PATCH v2 02/29] Documentation: nvmem: document lookup entries
From: Brian Norris <computersforpeace@gmail.com>
Date: 2018-08-31 20:30:35
Also in:
linux-arm-kernel, linux-i2c, linux-omap, lkml, netdev
On Fri, Aug 10, 2018 at 10:04:59AM +0200, Bartosz Golaszewski wrote:
quoted hunk ↗ jump to hunk
From: Bartosz Golaszewski <redacted> Describe the usage of nvmem cell lookup tables. Signed-off-by: Bartosz Golaszewski <redacted> --- 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