Add device managed APIs for i2c_new_dummy() and
i2c_unregister_device() so that it can be managed by
device framework for freeing it.
This helps on following:
1. Maintaining the resource allocation and deallocation
i2c_dummy = i2c_new_dummy();
devm_regmap_init_i2c(i2c_dummy, ®map_config)
On this case, the user of i2c_dummy which is
devm_regmap_init_i2c() is managed allocation where
i2c_new_dummy() is not.
On Free path, we have
i2c_unregister_device(i2c_dummy)
and later, device framework release the regmap. In this
case, client of i2c_dummy after the i2c_dummy.
By using devm apis, the sequence can be maintain
i2c_dummy = devm_i2c_new_dummy();
devm_regmap_init_i2c(i2c_dummy, ®map_config)
and resource deallocation will be done in reverse order
by device framework.
2. No need to release the i2c_client in error/remove path and hence
there is less code requirement.
Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
---
drivers/i2c/i2c-core.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/i2c.h | 6 +++++
2 files changed, 76 insertions(+)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index ffe715d..b512d72 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1158,6 +1158,76 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
}
EXPORT_SYMBOL_GPL(i2c_new_dummy);
+static void devm_i2c_dummy_release(struct device *dev, void *res)
+{
+ i2c_unregister_device(*(struct i2c_client **)res);
+}
+
+/**
+ * devm_i2c_new_dummy - Resource managed i2c_new_dummy()
+ * @dev: Device pointer for which this resouce belongs to.
+ * @adapter: the adapter managing the device
+ * @address: seven bit address to be used
+ * Context: can sleep
+ *
+ * This returns the new i2c client. Returns a valid pointer to struct
+ * i2c_client or NULL to indicate error. The i2c_cleint automatically
+ * be released when the device is unbound.
+ */
+struct i2c_client *devm_i2c_new_dummy(struct device *dev,
+ struct i2c_adapter *adapter,
+ u16 address)
+{
+ struct i2c_client **ptr, *i2c_dummy;
+
+ ptr = devres_alloc(devm_i2c_dummy_release, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ i2c_dummy = i2c_new_dummy(adapter, address);
+ if (i2c_dummy) {
+ *ptr = i2c_dummy;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return i2c_dummy;
+}
+EXPORT_SYMBOL_GPL(devm_i2c_new_dummy);
+
+static int devm_i2c_client_match(struct device *dev, void *res, void *data)
+{
+ struct i2c_client **r = res;
+
+ if (!r || !*r) {
+ WARN_ON(!r || !*r);
+ return 0;
+ }
+ return *r == data;
+}
+
+/**
+ * devm_i2c_unregister_device - Resource managed i2c_unregister_device()
+ * @dev: Device for which which resource was allocated.
+ * @client: i2c client to free
+ *
+ * Unregister a dummy i2c with devm_i2c_unregister_device().
+ * Normally this function will not need to be called and the resource
+ * management code will ensure that the resource is freed.
+ */
+void devm_i2c_unregister_device(struct device *dev, struct i2c_client *client)
+{
+ int rc;
+
+ rc = devres_release(dev, devm_i2c_dummy_release, devm_i2c_client_match,
+ client);
+ if (rc != 0)
+ WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_i2c_unregister_device);
+
/* ------------------------------------------------------------------------- */
/* I2C bus adapters -- one roots each I2C or SMBUS segment */
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 200cf13b..3abb1f9 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -350,6 +350,12 @@ extern struct i2c_client *
i2c_new_dummy(struct i2c_adapter *adap, u16 address);
extern void i2c_unregister_device(struct i2c_client *);
+
+extern struct i2c_client *devm_i2c_new_dummy(struct device *dev,
+ struct i2c_adapter *adapter,
+ u16 address);
+extern void devm_i2c_unregister_device(struct device *dev,
+ struct i2c_client *client);
#endif /* I2C */
/* Mainboard arch_initcall() code should register all its I2C devices.
--
2.1.4
--
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