[PATCH -next v3 01/15] HID: core: Use devm_add_action_or_reset helper to manage hid resources

Li Zetao
2024-09-10T15:36:41Z

By adding a custom action to the device, it can bind the hid resource
to the hid_device life cycle. The framework automatically close and stop
the hid resources before hid_device is released, and the users do not
need to pay attention to the timing of hid resource release.

Signed-off-by: Li Zetao <lizetao1@huawei.com>
---
v2 -> v3: None
v2: https://lore.kernel.org/all/20240909012313.500341-2-lizetao1@huawei.com/
v1 -> v2: Add function usage constraints in comments
v1: https://lore.kernel.org/all/20240904123607.3407364-2-lizetao1@huawei.com/

drivers/hid/hid-core.c | 44 ++++++++++++++++++++++++++++++++++++++++++
include/linux/hid.h | 2 ++
2 files changed, 46 insertions(+)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 30de92d0bf0f..132c81639753 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2416,6 +2416,50 @@ void hid_hw_close(struct hid_device *hdev)
}
EXPORT_SYMBOL_GPL(hid_hw_close);

+static void hid_hw_close_and_stop(void *data)
+{
+ struct hid_device *hdev = data;
+
+ hid_hw_close(hdev);
+ hid_hw_stop(hdev);
+}
+
+/**
+ * devm_hid_hw_start_and_open - manage hid resources through custom action
+ *
+ * @hdev: hid device
+ * @connect_mask: which outputs to connect, see HID_CONNECT_*
+ *
+ * Bind the hid resource to the hid_device life cycle and register
+ * an action to release the hid resource. The users do not need to
+ * pay attention to the release of hid.
+ *
+ * Some usage constraints of this function: hid_device also needs to be
+ * allocated through the Devres API, such as devm_kzalloc; hid_hw_stop should
+ * be followed immediately by hid_hw_close in the remove operation.
+ */
+
+int devm_hid_hw_start_and_open(struct hid_device *hdev, unsigned int connect_mask)
+{
+ int ret;
+
+ ret = hid_hw_start(hdev, connect_mask);
+ if (ret) {
+ hid_err(hdev, "hw start failed with %d\n", ret);
+ return ret;
+ }
+
+ ret = hid_hw_open(hdev);
+ if (ret) {
+ hid_err(hdev, "hw open failed with %d\n", ret);
+ hid_hw_stop(hdev);
+ return ret;
+ }
+
+ return devm_add_action_or_reset(&hdev->dev, hid_hw_close_and_stop, hdev);
+}
+EXPORT_SYMBOL_GPL(devm_hid_hw_start_and_open);
+
/**
* hid_hw_request - send report request to device
*
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 121d5b8bc867..0ce217aa5f62 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -1125,6 +1125,8 @@ int __must_check hid_hw_start(struct hid_device *hdev,
void hid_hw_stop(struct hid_device *hdev);
int __must_check hid_hw_open(struct hid_device *hdev);
void hid_hw_close(struct hid_device *hdev);
+int __must_check devm_hid_hw_start_and_open(struct hid_device *hdev,
+ unsigned int connect_mask);
void hid_hw_request(struct hid_device *hdev,
struct hid_report *report, enum hid_class_request reqtype);
int __hid_hw_raw_request(struct hid_device *hdev,
--
2.34.1