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Subject[PATCH v4 14/22] nvmem: resolve cells from DT at registration time
Date
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Currently we're creating a new cell structure everytime a DT user
calls nvmem_cell_get().

Change this behavior by resolving the cells during nvmem provider
registration and adding all cells to the provider's list. Make
of_nvmem_cell_get() just parse the phandle and look the cell up
in the relevant provider's list.

Don't drop the cell in nvmem_cell_put().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
drivers/nvmem/core.c | 123 ++++++++++++++++++++++++++-----------------
1 file changed, 75 insertions(+), 48 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 9329857f6137..13568e7ad178 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -456,6 +456,73 @@ static int nvmem_add_cells_from_table(struct nvmem_device *nvmem)
return rval;
}

+static struct nvmem_cell *
+nvmem_find_cell_by_index(struct nvmem_device *nvmem, int index)
+{
+ struct nvmem_cell *cell = NULL;
+ int i = 0;
+
+ mutex_lock(&nvmem_mutex);
+ list_for_each_entry(cell, &nvmem->cells, node) {
+ if (index == i++)
+ break;
+ }
+ mutex_unlock(&nvmem_mutex);
+
+ return cell;
+}
+
+static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
+{
+ struct device_node *parent, *child;
+ struct device *dev = &nvmem->dev;
+ struct nvmem_cell *cell;
+ const __be32 *addr;
+ int len;
+
+ parent = dev->of_node;
+
+ for_each_child_of_node(parent, child) {
+ addr = of_get_property(child, "reg", &len);
+ if (!addr || (len < 2 * sizeof(u32))) {
+ dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
+ return -EINVAL;
+ }
+
+ cell = kzalloc(sizeof(*cell), GFP_KERNEL);
+ if (!cell)
+ return -ENOMEM;
+
+ cell->nvmem = nvmem;
+ cell->offset = be32_to_cpup(addr++);
+ cell->bytes = be32_to_cpup(addr);
+ cell->name = child->name;
+
+ addr = of_get_property(child, "bits", &len);
+ if (addr && len == (2 * sizeof(u32))) {
+ cell->bit_offset = be32_to_cpup(addr++);
+ cell->nbits = be32_to_cpup(addr);
+ }
+
+ if (cell->nbits)
+ cell->bytes = DIV_ROUND_UP(
+ cell->nbits + cell->bit_offset,
+ BITS_PER_BYTE);
+
+ if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
+ dev_err(dev, "cell %s unaligned to nvmem stride %d\n",
+ cell->name, nvmem->stride);
+ /* Cells already added will be freed later. */
+ kfree(cell);
+ return -EINVAL;
+ }
+
+ nvmem_cell_add(cell);
+ }
+
+ return 0;
+}
+
/**
* nvmem_register() - Register a nvmem device for given nvmem_config.
* Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
@@ -546,6 +613,10 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
if (rval)
goto err_remove_cells;

+ rval = nvmem_add_cells_from_of(nvmem);
+ if (rval)
+ goto err_remove_cells;
+
return nvmem;

err_remove_cells:
@@ -848,10 +919,8 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
const char *name)
{
struct device_node *cell_np, *nvmem_np;
- struct nvmem_cell *cell;
struct nvmem_device *nvmem;
- const __be32 *addr;
- int rval, len;
+ struct nvmem_cell *cell;
int index = 0;

/* if cell name exists, find index to the name */
@@ -871,54 +940,13 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
if (IS_ERR(nvmem))
return ERR_CAST(nvmem);

- addr = of_get_property(cell_np, "reg", &len);
- if (!addr || (len < 2 * sizeof(u32))) {
- dev_err(&nvmem->dev, "nvmem: invalid reg on %pOF\n",
- cell_np);
- rval = -EINVAL;
- goto err_mem;
- }
-
- cell = kzalloc(sizeof(*cell), GFP_KERNEL);
+ cell = nvmem_find_cell_by_index(nvmem, index);
if (!cell) {
- rval = -ENOMEM;
- goto err_mem;
- }
-
- cell->nvmem = nvmem;
- cell->offset = be32_to_cpup(addr++);
- cell->bytes = be32_to_cpup(addr);
- cell->name = cell_np->name;
-
- addr = of_get_property(cell_np, "bits", &len);
- if (addr && len == (2 * sizeof(u32))) {
- cell->bit_offset = be32_to_cpup(addr++);
- cell->nbits = be32_to_cpup(addr);
- }
-
- if (cell->nbits)
- cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
- BITS_PER_BYTE);
-
- if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
- dev_err(&nvmem->dev,
- "cell %s unaligned to nvmem stride %d\n",
- cell->name, nvmem->stride);
- rval = -EINVAL;
- goto err_sanity;
+ __nvmem_device_put(nvmem);
+ return ERR_PTR(-ENOENT);
}

- nvmem_cell_add(cell);
-
return cell;
-
-err_sanity:
- kfree(cell);
-
-err_mem:
- __nvmem_device_put(nvmem);
-
- return ERR_PTR(rval);
}
EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
#endif
@@ -1024,7 +1052,6 @@ void nvmem_cell_put(struct nvmem_cell *cell)
struct nvmem_device *nvmem = cell->nvmem;

__nvmem_device_put(nvmem);
- nvmem_cell_drop(cell);
}
EXPORT_SYMBOL_GPL(nvmem_cell_put);

--
2.18.0
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