1 files changed, 111 insertions, 0 deletions
diff --git a/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-common.c b/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-common.c
new file mode 100644
index 000000000000..562933e08d62
--- /dev/null
+++ b/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-common.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for STM32 Digital Camera Memory Interface Pixel Processor
+ *
+ * Copyright (C) STMicroelectronics SA 2023
+ * Authors: Hugues Fruchet <hugues.fruchet@foss.st.com>
+ *          Alain Volmat <alain.volmat@foss.st.com>
+ *          for STMicroelectronics.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+
+#include "dcmipp-common.h"
+
+/* Helper function to allocate and initialize pads */
+struct media_pad *dcmipp_pads_init(u16 num_pads, const unsigned long *pads_flags)
+{
+	struct media_pad *pads;
+	unsigned int i;
+
+	/* Allocate memory for the pads */
+	pads = kcalloc(num_pads, sizeof(*pads), GFP_KERNEL);
+	if (!pads)
+		return ERR_PTR(-ENOMEM);
+
+	/* Initialize the pads */
+	for (i = 0; i < num_pads; i++) {
+		pads[i].index = i;
+		pads[i].flags = pads_flags[i];
+	}
+
+	return pads;
+}
+
+static const struct media_entity_operations dcmipp_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+int dcmipp_ent_sd_register(struct dcmipp_ent_device *ved,
+			   struct v4l2_subdev *sd,
+			   struct v4l2_device *v4l2_dev,
+			   const char *const name,
+			   u32 function,
+			   u16 num_pads,
+			   const unsigned long *pads_flag,
+			   const struct v4l2_subdev_internal_ops *sd_int_ops,
+			   const struct v4l2_subdev_ops *sd_ops,
+			   irq_handler_t handler,
+			   irq_handler_t thread_fn)
+{
+	int ret;
+
+	/* Allocate the pads. Should be released from the sd_int_op release */
+	ved->pads = dcmipp_pads_init(num_pads, pads_flag);
+	if (IS_ERR(ved->pads))
+		return PTR_ERR(ved->pads);
+
+	/* Fill the dcmipp_ent_device struct */
+	ved->ent = &sd->entity;
+
+	/* Initialize the subdev */
+	v4l2_subdev_init(sd, sd_ops);
+	sd->internal_ops = sd_int_ops;
+	sd->entity.function = function;
+	sd->entity.ops = &dcmipp_entity_ops;
+	sd->owner = THIS_MODULE;
+	strscpy(sd->name, name, sizeof(sd->name));
+	v4l2_set_subdevdata(sd, ved);
+
+	/* Expose this subdev to user space */
+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	if (sd->ctrl_handler)
+		sd->flags |= V4L2_SUBDEV_FL_HAS_EVENTS;
+
+	/* Initialize the media entity */
+	ret = media_entity_pads_init(&sd->entity, num_pads, ved->pads);
+	if (ret)
+		goto err_clean_pads;
+
+	ret = v4l2_subdev_init_finalize(sd);
+	if (ret < 0)
+		goto err_clean_m_ent;
+
+	/* Register the subdev with the v4l2 and the media framework */
+	ret = v4l2_device_register_subdev(v4l2_dev, sd);
+	if (ret) {
+		dev_err(v4l2_dev->dev,
+			"%s: subdev register failed (err=%d)\n",
+			name, ret);
+		goto err_clean_m_ent;
+	}
+
+	ved->handler = handler;
+	ved->thread_fn = thread_fn;
+
+	return 0;
+
+err_clean_m_ent:
+	media_entity_cleanup(&sd->entity);
+err_clean_pads:
+	dcmipp_pads_cleanup(ved->pads);
+	return ret;
+}
+
+void
+dcmipp_ent_sd_unregister(struct dcmipp_ent_device *ved, struct v4l2_subdev *sd)
+{
+	media_entity_cleanup(ved->ent);
+	v4l2_device_unregister_subdev(sd);
+}