summaryrefslogtreecommitdiffstats
path: root/Documentation/nvmem
diff options
context:
space:
mode:
authorMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-04-16 00:25:27 +0200
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-07-15 14:20:24 +0200
commita278295ccc2ddd1dc0ac8423a12ff6dd74f0d502 (patch)
tree44a1081449f60bd9ed3ea224f9d5a241be8ba88b /Documentation/nvmem
parentdocs: bus-devices: ti-gpmc.rst: convert it to ReST (diff)
downloadlinux-a278295ccc2ddd1dc0ac8423a12ff6dd74f0d502.tar.xz
linux-a278295ccc2ddd1dc0ac8423a12ff6dd74f0d502.zip
docs: nvmem: convert docs to ReST and rename to *.rst
In order to be able to add it into a doc book, we need first convert it to ReST. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - mark literal blocks; - adjust title markups. While this is not part of any book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'Documentation/nvmem')
-rw-r--r--Documentation/nvmem/nvmem.rst (renamed from Documentation/nvmem/nvmem.txt)112
1 files changed, 59 insertions, 53 deletions
diff --git a/Documentation/nvmem/nvmem.txt b/Documentation/nvmem/nvmem.rst
index fc2fe4b18655..3866b6e066d5 100644
--- a/Documentation/nvmem/nvmem.txt
+++ b/Documentation/nvmem/nvmem.rst
@@ -1,5 +1,10 @@
- NVMEM SUBSYSTEM
- Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+:orphan:
+
+===============
+NVMEM Subsystem
+===============
+
+ Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
This document explains the NVMEM Framework along with the APIs provided,
and how to use it.
@@ -40,54 +45,54 @@ nvmem_device pointer.
nvmem_unregister(nvmem) is used to unregister a previously registered provider.
-For example, a simple qfprom case:
+For example, a simple qfprom case::
-static struct nvmem_config econfig = {
+ static struct nvmem_config econfig = {
.name = "qfprom",
.owner = THIS_MODULE,
-};
+ };
-static int qfprom_probe(struct platform_device *pdev)
-{
+ static int qfprom_probe(struct platform_device *pdev)
+ {
...
econfig.dev = &pdev->dev;
nvmem = nvmem_register(&econfig);
...
-}
+ }
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().
Users of board files can define and register nvmem cells using the
-nvmem_cell_table struct:
+nvmem_cell_table struct::
-static struct nvmem_cell_info foo_nvmem_cells[] = {
+ static struct nvmem_cell_info foo_nvmem_cells[] = {
{
.name = "macaddr",
.offset = 0x7f00,
.bytes = ETH_ALEN,
}
-};
+ };
-static struct nvmem_cell_table foo_nvmem_cell_table = {
+ static struct nvmem_cell_table foo_nvmem_cell_table = {
.nvmem_name = "i2c-eeprom",
.cells = foo_nvmem_cells,
.ncells = ARRAY_SIZE(foo_nvmem_cells),
-};
+ };
-nvmem_add_cell_table(&foo_nvmem_cell_table);
+ nvmem_add_cell_table(&foo_nvmem_cell_table);
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:
+them with the nvmem framework from machine code as shown in the example below::
-static struct nvmem_cell_lookup foo_nvmem_lookup = {
+ static struct nvmem_cell_lookup foo_nvmem_lookup = {
.nvmem_name = "i2c-eeprom",
.cell_name = "macaddr",
.dev_id = "foo_mac.0",
.con_id = "mac-address",
-};
+ };
-nvmem_add_cell_lookups(&foo_nvmem_lookup, 1);
+ nvmem_add_cell_lookups(&foo_nvmem_lookup, 1);
NVMEM Consumers
+++++++++++++++
@@ -99,43 +104,43 @@ read from and to NVMEM.
=================================
NVMEM cells are the data entries/fields in the NVMEM.
-The NVMEM framework provides 3 APIs to read/write NVMEM cells.
+The NVMEM framework provides 3 APIs to read/write NVMEM cells::
-struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *name);
-struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *name);
+ struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *name);
+ struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *name);
-void nvmem_cell_put(struct nvmem_cell *cell);
-void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell);
+ void nvmem_cell_put(struct nvmem_cell *cell);
+ void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell);
-void *nvmem_cell_read(struct nvmem_cell *cell, ssize_t *len);
-int nvmem_cell_write(struct nvmem_cell *cell, void *buf, ssize_t len);
+ void *nvmem_cell_read(struct nvmem_cell *cell, ssize_t *len);
+ int nvmem_cell_write(struct nvmem_cell *cell, void *buf, ssize_t len);
-*nvmem_cell_get() apis will get a reference to nvmem cell for a given id,
+`*nvmem_cell_get()` apis will get a reference to nvmem cell for a given id,
and nvmem_cell_read/write() can then read or write to the cell.
-Once the usage of the cell is finished the consumer should call *nvmem_cell_put()
-to free all the allocation memory for the cell.
+Once the usage of the cell is finished the consumer should call
+`*nvmem_cell_put()` to free all the allocation memory for the cell.
4. Direct NVMEM device based consumer APIs
==========================================
In some instances it is necessary to directly read/write the NVMEM.
-To facilitate such consumers NVMEM framework provides below apis.
+To facilitate such consumers NVMEM framework provides below apis::
-struct nvmem_device *nvmem_device_get(struct device *dev, const char *name);
-struct nvmem_device *devm_nvmem_device_get(struct device *dev,
+ struct nvmem_device *nvmem_device_get(struct device *dev, const char *name);
+ struct nvmem_device *devm_nvmem_device_get(struct device *dev,
const char *name);
-void nvmem_device_put(struct nvmem_device *nvmem);
-int nvmem_device_read(struct nvmem_device *nvmem, unsigned int offset,
+ void nvmem_device_put(struct nvmem_device *nvmem);
+ int nvmem_device_read(struct nvmem_device *nvmem, unsigned int offset,
size_t bytes, void *buf);
-int nvmem_device_write(struct nvmem_device *nvmem, unsigned int offset,
+ int nvmem_device_write(struct nvmem_device *nvmem, unsigned int offset,
size_t bytes, void *buf);
-int nvmem_device_cell_read(struct nvmem_device *nvmem,
+ int nvmem_device_cell_read(struct nvmem_device *nvmem,
struct nvmem_cell_info *info, void *buf);
-int nvmem_device_cell_write(struct nvmem_device *nvmem,
+ int nvmem_device_cell_write(struct nvmem_device *nvmem,
struct nvmem_cell_info *info, void *buf);
Before the consumers can read/write NVMEM directly, it should get hold
-of nvmem_controller from one of the *nvmem_device_get() api.
+of nvmem_controller from one of the `*nvmem_device_get()` api.
The difference between these apis and cell based apis is that these apis always
take nvmem_device as parameter.
@@ -145,12 +150,12 @@ take nvmem_device as parameter.
When a consumer no longer needs the NVMEM, it has to release the reference
to the NVMEM it has obtained using the APIs mentioned in the above section.
-The NVMEM framework provides 2 APIs to release a reference to the NVMEM.
+The NVMEM framework provides 2 APIs to release a reference to the NVMEM::
-void nvmem_cell_put(struct nvmem_cell *cell);
-void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell);
-void nvmem_device_put(struct nvmem_device *nvmem);
-void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem);
+ void nvmem_cell_put(struct nvmem_cell *cell);
+ void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell);
+ void nvmem_device_put(struct nvmem_device *nvmem);
+ void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem);
Both these APIs are used to release a reference to the NVMEM and
devm_nvmem_cell_put and devm_nvmem_device_put destroys the devres associated
@@ -162,20 +167,21 @@ Userspace
6. Userspace binary interface
==============================
-Userspace can read/write the raw NVMEM file located at
-/sys/bus/nvmem/devices/*/nvmem
+Userspace can read/write the raw NVMEM file located at::
+
+ /sys/bus/nvmem/devices/*/nvmem
-ex:
+ex::
-hexdump /sys/bus/nvmem/devices/qfprom0/nvmem
+ hexdump /sys/bus/nvmem/devices/qfprom0/nvmem
-0000000 0000 0000 0000 0000 0000 0000 0000 0000
-*
-00000a0 db10 2240 0000 e000 0c00 0c00 0000 0c00
-0000000 0000 0000 0000 0000 0000 0000 0000 0000
-...
-*
-0001000
+ 0000000 0000 0000 0000 0000 0000 0000 0000 0000
+ *
+ 00000a0 db10 2240 0000 e000 0c00 0c00 0000 0c00
+ 0000000 0000 0000 0000 0000 0000 0000 0000 0000
+ ...
+ *
+ 0001000
7. DeviceTree Binding
=====================