[PATCH v9 1/5] nvmem: core: add nvmem_device_find

From: Thomas Bogendoerfer
Date: Thu Oct 10 2019 - 11:00:30 EST


nvmem_device_find provides a way to search for nvmem devices with
the help of a match function simlair to bus_find_device.

Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@xxxxxxx>
---
Documentation/driver-api/nvmem.rst | 2 ++
drivers/nvmem/core.c | 61 +++++++++++++++++---------------------
include/linux/nvmem-consumer.h | 9 ++++++
3 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/Documentation/driver-api/nvmem.rst b/Documentation/driver-api/nvmem.rst
index d9d958d5c824..287e86819640 100644
--- a/Documentation/driver-api/nvmem.rst
+++ b/Documentation/driver-api/nvmem.rst
@@ -129,6 +129,8 @@ 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);
+ struct nvmem_device *nvmem_device_find(void *data,
+ int (*match)(struct device *dev, const void *data));
void nvmem_device_put(struct nvmem_device *nvmem);
int nvmem_device_read(struct nvmem_device *nvmem, unsigned int offset,
size_t bytes, void *buf);
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 057d1ff87d5d..9f1ee9c766ec 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -76,33 +76,6 @@ static struct bus_type nvmem_bus_type = {
.name = "nvmem",
};

-static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np)
-{
- struct device *d;
-
- if (!nvmem_np)
- return NULL;
-
- d = bus_find_device_by_of_node(&nvmem_bus_type, nvmem_np);
-
- if (!d)
- return NULL;
-
- return to_nvmem_device(d);
-}
-
-static struct nvmem_device *nvmem_find(const char *name)
-{
- struct device *d;
-
- d = bus_find_device_by_name(&nvmem_bus_type, NULL, name);
-
- if (!d)
- return NULL;
-
- return to_nvmem_device(d);
-}
-
static void nvmem_cell_drop(struct nvmem_cell *cell)
{
blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell);
@@ -532,13 +505,16 @@ int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
}
EXPORT_SYMBOL(devm_nvmem_unregister);

-static struct nvmem_device *__nvmem_device_get(struct device_node *np,
- const char *nvmem_name)
+static struct nvmem_device *__nvmem_device_get(void *data,
+ int (*match)(struct device *dev, const void *data))
{
struct nvmem_device *nvmem = NULL;
+ struct device *dev;

mutex_lock(&nvmem_mutex);
- nvmem = np ? of_nvmem_find(np) : nvmem_find(nvmem_name);
+ dev = bus_find_device(&nvmem_bus_type, NULL, data, match);
+ if (dev)
+ nvmem = to_nvmem_device(dev);
mutex_unlock(&nvmem_mutex);
if (!nvmem)
return ERR_PTR(-EPROBE_DEFER);
@@ -587,7 +563,7 @@ struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id)
if (!nvmem_np)
return ERR_PTR(-ENOENT);

- return __nvmem_device_get(nvmem_np, NULL);
+ return __nvmem_device_get(nvmem_np, device_match_of_node);
}
EXPORT_SYMBOL_GPL(of_nvmem_device_get);
#endif
@@ -613,10 +589,26 @@ struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name)

}

- return __nvmem_device_get(NULL, dev_name);
+ return __nvmem_device_get((void *)dev_name, device_match_name);
}
EXPORT_SYMBOL_GPL(nvmem_device_get);

+/**
+ * nvmem_device_find() - Find nvmem device with matching function
+ *
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
+ *
+ * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
+ * on success.
+ */
+struct nvmem_device *nvmem_device_find(void *data,
+ int (*match)(struct device *dev, const void *data))
+{
+ return __nvmem_device_get(data, match);
+}
+EXPORT_SYMBOL_GPL(nvmem_device_find);
+
static int devm_nvmem_device_match(struct device *dev, void *res, void *data)
{
struct nvmem_device **nvmem = res;
@@ -710,7 +702,8 @@ nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
if ((strcmp(lookup->dev_id, dev_id) == 0) &&
(strcmp(lookup->con_id, con_id) == 0)) {
/* This is the right entry. */
- nvmem = __nvmem_device_get(NULL, lookup->nvmem_name);
+ nvmem = __nvmem_device_get((void *)lookup->nvmem_name,
+ device_match_name);
if (IS_ERR(nvmem)) {
/* Provider may not be registered yet. */
cell = ERR_CAST(nvmem);
@@ -780,7 +773,7 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
if (!nvmem_np)
return ERR_PTR(-EINVAL);

- nvmem = __nvmem_device_get(nvmem_np, NULL);
+ nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
of_node_put(nvmem_np);
if (IS_ERR(nvmem))
return ERR_CAST(nvmem);
diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index 8f8be5b00060..02dc4aa992b2 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -89,6 +89,9 @@ void nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries,
int nvmem_register_notifier(struct notifier_block *nb);
int nvmem_unregister_notifier(struct notifier_block *nb);

+struct nvmem_device *nvmem_device_find(void *data,
+ int (*match)(struct device *dev, const void *data));
+
#else

static inline struct nvmem_cell *nvmem_cell_get(struct device *dev,
@@ -204,6 +207,12 @@ static inline int nvmem_unregister_notifier(struct notifier_block *nb)
return -EOPNOTSUPP;
}

+static inline struct nvmem_device *nvmem_device_find(void *data,
+ int (*match)(struct device *dev, const void *data))
+{
+ return NULL;
+}
+
#endif /* CONFIG_NVMEM */

#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
--
2.16.4