[PATCH v4 09/20] nvmem: core: add nvmem_add_one_cell()

[Michael Walle <michael@walle.cc>]

Add a new function to add exactly one cell. This will be used by the
nvmem layout drivers to add custom cells. In contrast to the
nvmem_add_cells(), this has the advantage that we don't have to assemble
a list of cells on runtime.

Signed-off-by: Michael Walle <michael@walle.cc>
---
changes since v3:
 - none

changes since v2:
 - add EXPORT_SYMBOL_GPL()

changes since v1:
 - none

 drivers/nvmem/core.c           | 59 ++++++++++++++++++++--------------
 include/linux/nvmem-provider.h |  8 +++++
 2 files changed, 43 insertions(+), 24 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 7c76e0e0072e..cb25bf29dea7 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -501,6 +501,36 @@ static int nvmem_cell_info_to_nvmem_cell_entry(struct nvmem_device *nvmem,
 	return 0;
 }
 
+/**
+ * nvmem_add_one_cell() - Add one cell information to an nvmem device
+ *
+ * @nvmem: nvmem device to add cells to.
+ * @info: nvmem cell info to add to the device
+ *
+ * Return: 0 or negative error code on failure.
+ */
+int nvmem_add_one_cell(struct nvmem_device *nvmem,
+		       const struct nvmem_cell_info *info)
+{
+	struct nvmem_cell_entry *cell;
+	int rval;
+
+	cell = kzalloc(sizeof(*cell), GFP_KERNEL);
+	if (!cell)
+		return -ENOMEM;
+
+	rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, info, cell);
+	if (rval) {
+		kfree(cell);
+		return rval;
+	}
+
+	nvmem_cell_entry_add(cell);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvmem_add_one_cell);
+
 /**
  * nvmem_add_cells() - Add cell information to an nvmem device
  *
@@ -514,34 +544,15 @@ static int nvmem_add_cells(struct nvmem_device *nvmem,
 		    const struct nvmem_cell_info *info,
 		    int ncells)
 {
-	struct nvmem_cell_entry **cells;
-	int i, rval = 0;
-
-	cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL);
-	if (!cells)
-		return -ENOMEM;
+	int i, rval;
 
 	for (i = 0; i < ncells; i++) {
-		cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL);
-		if (!cells[i]) {
-			rval = -ENOMEM;
-			goto out;
-		}
-
-		rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, &info[i], cells[i]);
-		if (rval) {
-			kfree(cells[i]);
-			goto out;
-		}
-
-		nvmem_cell_entry_add(cells[i]);
+		rval = nvmem_add_one_cell(nvmem, &info[i]);
+		if (rval)
+			return rval;
 	}
 
-out:
-	/* remove tmp array */
-	kfree(cells);
-
-	return rval;
+	return 0;
 }
 
 /**
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 14a32a1bc249..385d29168008 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -155,6 +155,9 @@ struct nvmem_device *devm_nvmem_register(struct device *dev,
 void nvmem_add_cell_table(struct nvmem_cell_table *table);
 void nvmem_del_cell_table(struct nvmem_cell_table *table);
 
+int nvmem_add_one_cell(struct nvmem_device *nvmem,
+		       const struct nvmem_cell_info *info);
+
 #else
 
 static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
@@ -172,6 +175,11 @@ devm_nvmem_register(struct device *dev, const struct nvmem_config *c)
 
 static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {}
 static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}
+static inline int nvmem_add_one_cell(struct nvmem_device *nvmem,
+				     const struct nvmem_cell_info *info)
+{
+	return -EOPNOTSUPP;
+}
 
 #endif /* CONFIG_NVMEM */
 #endif  /* ifndef _LINUX_NVMEM_PROVIDER_H */
-- 
2.30.2