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>

diff --git a/Documentation/nvmem/nvmem.rst b/Documentation/nvmem/nvmem.rst
new file mode 100644 (file)
index 0000000..3866b6e
--- /dev/null
+++ b/Documentation/nvmem/nvmem.rst
@@ -0,0 +1,189 @@
+: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.
+
+1. Introduction
+===============
+*NVMEM* is the abbreviation for Non Volatile Memory layer. It is used to
+retrieve configuration of SOC or Device specific data from non volatile
+memories like eeprom, efuses and so on.
+
+Before this framework existed, NVMEM drivers like eeprom were stored in
+drivers/misc, where they all had to duplicate pretty much the same code to
+register a sysfs file, allow in-kernel users to access the content of the
+devices they were driving, etc.
+
+This was also a problem as far as other in-kernel users were involved, since
+the solutions used were pretty much different from one driver to another, there
+was a rather big abstraction leak.
+
+This framework aims at solve these problems. It also introduces DT
+representation for consumer devices to go get the data they require (MAC
+Addresses, SoC/Revision ID, part numbers, and so on) from the NVMEMs. This
+framework is based on regmap, so that most of the abstraction available in
+regmap can be reused, across multiple types of buses.
+
+NVMEM Providers
++++++++++++++++
+
+NVMEM provider refers to an entity that implements methods to initialize, read
+and write the non-volatile memory.
+
+2. Registering/Unregistering the NVMEM provider
+===============================================
+
+A NVMEM provider can register with NVMEM core by supplying relevant
+nvmem configuration to nvmem_register(), on success core would return a valid
+nvmem_device pointer.
+
+nvmem_unregister(nvmem) is used to unregister a previously registered provider.
+
+For example, a simple qfprom case::
+
+  static struct nvmem_config econfig = {
+       .name = "qfprom",
+       .owner = THIS_MODULE,
+  };
+
+  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::
+
+  static struct nvmem_cell_info foo_nvmem_cells[] = {
+       {
+               .name           = "macaddr",
+               .offset         = 0x7f00,
+               .bytes          = ETH_ALEN,
+       }
+  };
+
+  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);
+
+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 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 Consumers
++++++++++++++++
+
+NVMEM consumers are the entities which make use of the NVMEM provider to
+read from and to NVMEM.
+
+3. NVMEM cell based consumer APIs
+=================================
+
+NVMEM cells are the data entries/fields in the NVMEM.
+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);
+
+  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);
+
+`*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.
+
+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::
+
+  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,
+                     size_t bytes, void *buf);
+  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,
+                          struct nvmem_cell_info *info, void *buf);
+  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.
+
+The difference between these apis and cell based apis is that these apis always
+take nvmem_device as parameter.
+
+5. Releasing a reference to the NVMEM
+=====================================
+
+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::
+
+  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
+with this NVMEM.
+
+Userspace
++++++++++
+
+6. Userspace binary interface
+==============================
+
+Userspace can read/write the raw NVMEM file located at::
+
+       /sys/bus/nvmem/devices/*/nvmem
+
+ex::
+
+  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
+
+7. DeviceTree Binding
+=====================
+
+See Documentation/devicetree/bindings/nvmem/nvmem.txt

diff --git a/Documentation/nvmem/nvmem.txt b/Documentation/nvmem/nvmem.txt
deleted file mode 100644 (file)
index fc2fe4b..0000000
--- a/Documentation/nvmem/nvmem.txt
+++ /dev/null
@@ -1,183 +0,0 @@
-                           NVMEM SUBSYSTEM
-         Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
-
-This document explains the NVMEM Framework along with the APIs provided,
-and how to use it.
-
-1. Introduction
-===============
-*NVMEM* is the abbreviation for Non Volatile Memory layer. It is used to
-retrieve configuration of SOC or Device specific data from non volatile
-memories like eeprom, efuses and so on.
-
-Before this framework existed, NVMEM drivers like eeprom were stored in
-drivers/misc, where they all had to duplicate pretty much the same code to
-register a sysfs file, allow in-kernel users to access the content of the
-devices they were driving, etc.
-
-This was also a problem as far as other in-kernel users were involved, since
-the solutions used were pretty much different from one driver to another, there
-was a rather big abstraction leak.
-
-This framework aims at solve these problems. It also introduces DT
-representation for consumer devices to go get the data they require (MAC
-Addresses, SoC/Revision ID, part numbers, and so on) from the NVMEMs. This
-framework is based on regmap, so that most of the abstraction available in
-regmap can be reused, across multiple types of buses.
-
-NVMEM Providers
-+++++++++++++++
-
-NVMEM provider refers to an entity that implements methods to initialize, read
-and write the non-volatile memory.
-
-2. Registering/Unregistering the NVMEM provider
-===============================================
-
-A NVMEM provider can register with NVMEM core by supplying relevant
-nvmem configuration to nvmem_register(), on success core would return a valid
-nvmem_device pointer.
-
-nvmem_unregister(nvmem) is used to unregister a previously registered provider.
-
-For example, a simple qfprom case:
-
-static struct nvmem_config econfig = {
-       .name = "qfprom",
-       .owner = THIS_MODULE,
-};
-
-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:
-
-static struct nvmem_cell_info foo_nvmem_cells[] = {
-       {
-               .name           = "macaddr",
-               .offset         = 0x7f00,
-               .bytes          = ETH_ALEN,
-       }
-};
-
-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);
-
-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 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 Consumers
-+++++++++++++++
-
-NVMEM consumers are the entities which make use of the NVMEM provider to
-read from and to NVMEM.
-
-3. NVMEM cell based consumer APIs
-=================================
-
-NVMEM cells are the data entries/fields in the NVMEM.
-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);
-
-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);
-
-*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.
-
-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.
-
-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,
-                     size_t bytes, void *buf);
-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,
-                          struct nvmem_cell_info *info, void *buf);
-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.
-
-The difference between these apis and cell based apis is that these apis always
-take nvmem_device as parameter.
-
-5. Releasing a reference to the NVMEM
-=====================================
-
-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.
-
-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
-with this NVMEM.
-
-Userspace
-+++++++++
-
-6. Userspace binary interface
-==============================
-
-Userspace can read/write the raw NVMEM file located at
-/sys/bus/nvmem/devices/*/nvmem
-
-ex:
-
-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
-
-7. DeviceTree Binding
-=====================
-
-See Documentation/devicetree/bindings/nvmem/nvmem.txt