Patch "drm/mipi-dsi: Create devm device registration" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/mipi-dsi: Create devm device registration

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-mipi-dsi-create-devm-device-registration.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c3d566132ac0cbd3f5eec283f97b610e8a88fd11
Author: Maxime Ripard <mripard@xxxxxxxxxx>
Date:   Fri Sep 10 12:11:57 2021 +0200

    drm/mipi-dsi: Create devm device registration
    
    [ Upstream commit a1419fb4a73e47f0eab2985dff594ed52397471b ]
    
    Devices that take their data through the MIPI-DSI bus but are controlled
    through a secondary bus like I2C have to register a secondary device on
    the MIPI-DSI bus through the mipi_dsi_device_register_full() function.
    
    At removal or when an error occurs, that device needs to be removed
    through a call to mipi_dsi_device_unregister().
    
    Let's create a device-managed variant of the registration function that
    will automatically unregister the device at unbind.
    
    Reviewed-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
    Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20210910101218.1632297-4-maxime@xxxxxxxxxx
    Stable-dep-of: 941882a0e96d ("drm/bridge: lt8912b: Fix bridge_detach")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 0c806e99e8690..bedbbfeab2a98 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -246,6 +246,52 @@ void mipi_dsi_device_unregister(struct mipi_dsi_device *dsi)
 }
 EXPORT_SYMBOL(mipi_dsi_device_unregister);
 
+static void devm_mipi_dsi_device_unregister(void *arg)
+{
+	struct mipi_dsi_device *dsi = arg;
+
+	mipi_dsi_device_unregister(dsi);
+}
+
+/**
+ * devm_mipi_dsi_device_register_full - create a managed MIPI DSI device
+ * @dev: device to tie the MIPI-DSI device lifetime to
+ * @host: DSI host to which this device is connected
+ * @info: pointer to template containing DSI device information
+ *
+ * Create a MIPI DSI device by using the device information provided by
+ * mipi_dsi_device_info template
+ *
+ * This is the managed version of mipi_dsi_device_register_full() which
+ * automatically calls mipi_dsi_device_unregister() when @dev is
+ * unbound.
+ *
+ * Returns:
+ * A pointer to the newly created MIPI DSI device, or, a pointer encoded
+ * with an error
+ */
+struct mipi_dsi_device *
+devm_mipi_dsi_device_register_full(struct device *dev,
+				   struct mipi_dsi_host *host,
+				   const struct mipi_dsi_device_info *info)
+{
+	struct mipi_dsi_device *dsi;
+	int ret;
+
+	dsi = mipi_dsi_device_register_full(host, info);
+	if (IS_ERR(dsi))
+		return dsi;
+
+	ret = devm_add_action_or_reset(dev,
+				       devm_mipi_dsi_device_unregister,
+				       dsi);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return dsi;
+}
+EXPORT_SYMBOL_GPL(devm_mipi_dsi_device_register_full);
+
 static DEFINE_MUTEX(host_lock);
 static LIST_HEAD(host_list);
 
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 1d263eb0b2e12..5105464052704 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -227,6 +227,9 @@ struct mipi_dsi_device *
 mipi_dsi_device_register_full(struct mipi_dsi_host *host,
 			      const struct mipi_dsi_device_info *info);
 void mipi_dsi_device_unregister(struct mipi_dsi_device *dsi);
+struct mipi_dsi_device *
+devm_mipi_dsi_device_register_full(struct device *dev, struct mipi_dsi_host *host,
+				   const struct mipi_dsi_device_info *info);
 struct mipi_dsi_device *of_find_mipi_dsi_device_by_node(struct device_node *np);
 int mipi_dsi_attach(struct mipi_dsi_device *dsi);
 int mipi_dsi_detach(struct mipi_dsi_device *dsi);