[PATCH v4 03/24] drm/mipi-dsi: Create devm device registration

From: Maxime Ripard
Date: Fri Sep 10 2021 - 06:12:56 EST


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>
---
drivers/gpu/drm/drm_mipi_dsi.c | 46 ++++++++++++++++++++++++++++++++++
include/drm/drm_mipi_dsi.h | 3 +++
2 files changed, 49 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 5dd475e82995..ddf67463eaa1 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 af7ba8071eb0..d0032e435e08 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);
--
2.31.1