nvmem: Add nvmem_device based consumer apis.

This patch adds read/write apis which are based on nvmem_device. It is
common that the drivers like omap cape manager or qcom cpr driver to
access bytes directly at particular offset in the eeprom and not from
nvmem cell info in DT. These driver would need to get access to the nvmem
directly, which is what these new APIS provide.

These wrapper apis would help such users to avoid code duplication in
there drivers and also avoid them reading a big eeprom blob and parsing
it internally in there driver.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 73 insertions, 0 deletions

diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index 297cc67b7211..9bb77d3ed6e0 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -16,6 +16,7 @@ struct device;
 struct device_node;
 /* consumer cookie */
 struct nvmem_cell;
+struct nvmem_device;
 
 struct nvmem_cell_info {
         const char              *name;
@@ -35,6 +36,21 @@ void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell);
 void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len);
 int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len);
 
+/* direct nvmem device read/write interface */
+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);
+void devm_nvmem_device_put(struct device *dev, 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);
+ssize_t 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);
+
 #else
 
 static inline struct nvmem_cell *nvmem_cell_get(struct device *dev,
@@ -68,17 +84,74 @@ static inline int nvmem_cell_write(struct nvmem_cell *cell,
 {
         return -ENOSYS;
 }
+
+static inline struct nvmem_device *nvmem_device_get(struct device *dev,
+                                                    const char *name)
+{
+        return ERR_PTR(-ENOSYS);
+}
+
+static inline struct nvmem_device *devm_nvmem_device_get(struct device *dev,
+                                                         const char *name)
+{
+        return ERR_PTR(-ENOSYS);
+}
+
+static inline void nvmem_device_put(struct nvmem_device *nvmem)
+{
+}
+
+static inline void devm_nvmem_device_put(struct device *dev,
+                                         struct nvmem_device *nvmem)
+{
+}
+
+static inline ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
+                                         struct nvmem_cell_info *info,
+                                         void *buf)
+{
+        return -ENOSYS;
+}
+
+static inline int nvmem_device_cell_write(struct nvmem_device *nvmem,
+                                          struct nvmem_cell_info *info,
+                                          void *buf)
+{
+        return -ENOSYS;
+}
+
+static inline int nvmem_device_read(struct nvmem_device *nvmem,
+                                    unsigned int offset, size_t bytes,
+                                    void *buf)
+{
+        return -ENOSYS;
+}
+
+static inline int nvmem_device_write(struct nvmem_device *nvmem,
+                                     unsigned int offset, size_t bytes,
+                                     void *buf)
+{
+        return -ENOSYS;
+}
 #endif /* CONFIG_NVMEM */
 
 #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
 struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
                                      const char *name);
+struct nvmem_device *of_nvmem_device_get(struct device_node *np,
+                                         const char *name);
 #else
 static inline struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
                                      const char *name)
 {
         return ERR_PTR(-ENOSYS);
 }
+
+static inline struct nvmem_device *of_nvmem_device_get(struct device_node *np,
+                                                       const char *name)
+{
+        return ERR_PTR(-ENOSYS);
+}
 #endif /* CONFIG_NVMEM && CONFIG_OF */
 
 #endif  /* ifndef _LINUX_NVMEM_CONSUMER_H */