From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>Overall the idea look fine to me.
We can currently only register nvmem cells from device tree or by
manually calling nvmem_add_cells(). The latter options however forces
users to make sure that the nvmem provider with which the cells are
associated is registered before the call.
This patch proposes a new solution inspired by other frameworks that
offer resource lookups (GPIO, PWM etc.). It adds a function that allows
machine code to register nvmem lookup which are later lazily used to
add corresponding nvmem cells.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
drivers/nvmem/core.c | 57 +++++++++++++++++++++++++++++++++-
include/linux/nvmem-consumer.h | 6 ++++
include/linux/nvmem-provider.h | 6 ++++
3 files changed, 68 insertions(+), 1 deletion(-)
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index b5b0cdc21d01..a2e87b464319 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -62,6 +62,9 @@ static DEFINE_IDA(nvmem_ida);
static LIST_HEAD(nvmem_cells);
static DEFINE_MUTEX(nvmem_cells_mutex);
+static LIST_HEAD(nvmem_cell_lookups);
+static DEFINE_MUTEX(nvmem_lookup_mutex);
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key eeprom_lock_key;
#endif
@@ -247,6 +250,23 @@ static const struct attribute_group *nvmem_ro_root_dev_groups[] = {
NULL,
};
+/**
+ * nvmem_register_lookup() - register a number of nvmem cell lookup entries
+ *
+ * @lookup: array of nvmem cell lookup entries
+ * @nentries: number of lookup entries in the array
+ */
+void nvmem_register_lookup(struct nvmem_cell_lookup *lookup, size_t nentries)
+{
+ int i;
+ > + mutex_lock(&nvmem_lookup_mutex);
+ for (i = 0; i < nentries; i++)
+ list_add_tail(&lookup[i].list, &nvmem_cell_lookups);
+ mutex_unlock(&nvmem_lookup_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmem_register_lookup);
+
static void nvmem_release(struct device *dev)
{
struct nvmem_device *nvmem = to_nvmem_device(dev);
@@ -916,6 +936,37 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
#endif