i2c: core: Introduce i2c_client_get_device_id helper function

Introduces new helper function to aid in .probe_new() refactors. In order
to use existing i2c_get_device_id() on the probe callback, the device
match table needs to be accessible in that function, which would require
bigger refactors in some drivers using the deprecated .probe callback.

This issue was discussed in more detail in the IIO mailing list.

Link: https://lore.kernel.org/all/20221023132302.911644-11-u.kleine-koenig@pengutronix.de/
Suggested-by: Nuno Sá <noname.nuno@gmail.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index b4edf10e8fd06a575bb1e8f8f494b9a2839c54e7..9aa7b9d9a485611f7630e397fb89702b3332f1ca 100644 (file)
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -2236,6 +2236,20 @@ int i2c_get_device_id(const struct i2c_client *client,
 }
 EXPORT_SYMBOL_GPL(i2c_get_device_id);
 
+/**
+ * i2c_client_get_device_id - get the driver match table entry of a device
+ * @client: the device to query. The device must be bound to a driver
+ *
+ * Returns a pointer to the matching entry if found, NULL otherwise.
+ */
+const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client)
+{
+       const struct i2c_driver *drv = to_i2c_driver(client->dev.driver);
+
+       return i2c_match_id(drv->id_table, client);
+}
+EXPORT_SYMBOL_GPL(i2c_client_get_device_id);
+
 /* ----------------------------------------------------
  * the i2c address scanning function
  * Will not work for 10-bit addresses!

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index f7c49bbdb8a185e166ebb9fdd3482e95427927cb..d84e0e99f084e4954fd8c6289cb5593d03098412 100644 (file)
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -189,6 +189,7 @@ s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
                                              u8 *values);
 int i2c_get_device_id(const struct i2c_client *client,
                      struct i2c_device_identity *id);
+const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client);
 #endif /* I2C */
 
 /**