Hi Bartosz, thanks for the review.

On Thu, 2020-11-05 at 10:13 +0100, Bartosz Golaszewski wrote:

quoted

+/**
+ * devm_rpi_firmware_get - Get pointer to rpi_firmware structure.
+ * @firmware_node:    Pointer to the firmware Device Tree node.
+ *
+ * Returns NULL is the firmware device is not ready.
+ */
+struct rpi_firmware *devm_rpi_firmware_get(struct device *dev,
+                                          struct device_node *firmware_node)
+{
+       struct platform_device *pdev = of_find_device_by_node(firmware_node);
+       struct rpi_firmware *fw;
+
+       if (!pdev)
+               return NULL;
+
+       fw = platform_get_drvdata(pdev);
+       if (!fw)
+               return NULL;
+
+       if (!refcount_inc_not_zero(&fw->consumers))
+               return NULL;
+
+       if (devm_add_action_or_reset(dev, rpi_firmware_put, fw))
+               return NULL;
+
+       return fw;
+}
+EXPORT_SYMBOL_GPL(devm_rpi_firmware_get);

Usually I'd expect the devres variant to simply call
rpi_firmware_get() and then schedule a release callback which would
call whatever function is the release counterpart for it currently.
Devres actions are for drivers which want to schedule some more
unusual tasks at driver detach. Any reason for designing it this way?

Yes, see patch #8 where I get rid of rpi_firmware_get() altogether after
converting all users to devres. Since there is no use for the vanilla version
of the function anymore, I figured it'd be better to merge everything into
devm_rpi_firmware_get(). That said it's not something I have strong feelings
about.

Regards,
Nicolas