From: Herve Codina <herve.codina@bootlin.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Lizhi Hou <lizhi.hou@amd.com>, Rob Herring <robh@kernel.org>
Cc: "Max Zhen" <max.zhen@amd.com>,
"Sonal Santan" <sonal.santan@amd.com>,
"Stefano Stabellini" <stefano.stabellini@xilinx.com>,
"Jonathan Cameron" <Jonathan.Cameron@Huawei.com>,
"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
"Allan Nielsen" <allan.nielsen@microchip.com>,
"Horatiu Vultur" <horatiu.vultur@microchip.com>,
"Steen Hegelund" <steen.hegelund@microchip.com>,
"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
"Herve Codina" <herve.codina@bootlin.com>,
stable@vger.kernel.org
Subject: [PATCH v3 1/2] driver core: Introduce device_{add,remove}_of_node()
Date: Mon, 25 Mar 2024 16:39:14 +0100 [thread overview]
Message-ID: <20240325153919.199337-2-herve.codina@bootlin.com> (raw)
In-Reply-To: <20240325153919.199337-1-herve.codina@bootlin.com>
An of_node can be duplicated from an existing device using
device_set_of_node_from_dev() or initialized using device_set_node()
In both cases, these functions have to be called before the device_add()
call in order to have the of_node link created in the device sysfs
directory. Further more, these function cannot prevent any of_node
and/or fwnode overwrites.
When adding an of_node on an already present device, the following
operations need to be done:
- Attach the of_node if no of_node were already attached
- Attach the of_node as a fwnode if no fwnode were already attached
- Create the of_node sysfs link if needed
This is the purpose of device_add_of_node().
device_remove_of_node() reverts the operations done by
device_add_of_node().
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
drivers/base/core.c | 74 ++++++++++++++++++++++++++++++++++++++++++
include/linux/device.h | 2 ++
2 files changed, 76 insertions(+)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 521757408fc0..7e3af0ad770a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -5127,6 +5127,80 @@ void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
}
EXPORT_SYMBOL_GPL(set_secondary_fwnode);
+/**
+ * device_remove_of_node - Remove an of_node from a device
+ * @dev: device whose device-tree node is being removed
+ */
+void device_remove_of_node(struct device *dev)
+{
+ dev = get_device(dev);
+ if (!dev)
+ return;
+
+ if (!dev->of_node)
+ goto end;
+
+ sysfs_remove_link(&dev->kobj, "of_node");
+
+ if (dev->fwnode == of_fwnode_handle(dev->of_node))
+ dev->fwnode = NULL;
+
+ of_node_put(dev->of_node);
+ dev->of_node = NULL;
+
+end:
+ put_device(dev);
+}
+EXPORT_SYMBOL_GPL(device_remove_of_node);
+
+/**
+ * device_add_of_node - Add an of_node to an existing device
+ * @dev: device whose device-tree node is being added
+ * @of_node: of_node to add
+ */
+void device_add_of_node(struct device *dev, struct device_node *of_node)
+{
+ int ret;
+
+ if (!of_node)
+ return;
+
+ dev = get_device(dev);
+ if (!dev)
+ return;
+
+ if (dev->of_node) {
+ dev_warn(dev, "Replace node %pOF with %pOF\n", dev->of_node, of_node);
+ device_remove_of_node(dev);
+ }
+
+ dev->of_node = of_node_get(of_node);
+
+ if (!dev->fwnode)
+ dev->fwnode = of_fwnode_handle(of_node);
+
+ if (!dev->p) {
+ /*
+ * device_add() was not previously called.
+ * The of_node link will be created when device_add() is called.
+ */
+ goto end;
+ }
+
+ /*
+ * device_add() was previously called and so the of_node link was not
+ * created by device_add_class_symlinks().
+ * Create this link now.
+ */
+ ret = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node");
+ if (ret)
+ dev_warn(dev, "Error %d creating of_node link\n", ret);
+
+end:
+ put_device(dev);
+}
+EXPORT_SYMBOL_GPL(device_add_of_node);
+
/**
* device_set_of_node_from_dev - reuse device-tree node of another device
* @dev: device whose device-tree node is being set
diff --git a/include/linux/device.h b/include/linux/device.h
index 97c4b046c09d..1795121dee9a 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1127,6 +1127,8 @@ int device_offline(struct device *dev);
int device_online(struct device *dev);
void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
+void device_add_of_node(struct device *dev, struct device_node *of_node);
+void device_remove_of_node(struct device *dev);
void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
void device_set_node(struct device *dev, struct fwnode_handle *fwnode);
--
2.44.0
next prev parent reply other threads:[~2024-03-25 15:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-25 15:39 [PATCH v3 0/2] Attach DT nodes to existing PCI devices Herve Codina
2024-03-25 15:39 ` Herve Codina [this message]
2024-03-25 15:39 ` [PATCH v3 2/2] PCI: of: Attach created of_node to existing device Herve Codina
2024-04-11 13:23 ` Greg Kroah-Hartman
2024-04-11 20:34 ` Rob Herring
2024-04-12 7:41 ` Greg Kroah-Hartman
2024-04-12 8:10 ` Herve Codina
2024-04-08 12:43 ` [PATCH v3 0/2] Attach DT nodes to existing PCI devices Herve Codina
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