media: rockchip: add driver for the rockchip camera interface

Add the skeleton for a media controller centric V4L2 driver for the
Rockchip Camera Interface (CIF).
The skeleton features support for the PX30 Video Input Processor (VIP)
and the RK3568 Video Capture (VICAP) unit.

Tested-by: Gerald Loacker <[e-mail]>
Reviewed-by: Gerald Loacker <[e-mail]>
Reviewed-by: Bryan O'Donoghue <[e-mail]>
Reviewed-by: Mehdi Djait <[e-mail]>
Signed-off-by: Michael Riesch <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

MAINTAINERS

···
 F:	Documentation/admin-guide/media/rkcif*
 F:	Documentation/devicetree/bindings/media/rockchip,px30-vip.yaml
 F:	Documentation/devicetree/bindings/media/rockchip,rk3568-vicap.yaml
+F:	drivers/media/platform/rockchip/rkcif/
 
 ROCKCHIP CRYPTO DRIVERS
 M:	Corentin Labbe <[e-mail]>

drivers/media/platform/rockchip/Kconfig

···
 comment "Rockchip media platform drivers"
 
 source "drivers/media/platform/rockchip/rga/Kconfig"
+source "drivers/media/platform/rockchip/rkcif/Kconfig"
 source "drivers/media/platform/rockchip/rkisp1/Kconfig"
 source "drivers/media/platform/rockchip/rkvdec/Kconfig"

drivers/media/platform/rockchip/Makefile

···
 # SPDX-License-Identifier: GPL-2.0-only
 obj-y += rga/
+obj-y += rkcif/
 obj-y += rkisp1/
 obj-y += rkvdec/

drivers/media/platform/rockchip/rkcif/Kconfig

···
+config VIDEO_ROCKCHIP_CIF
+	tristate "Rockchip Camera Interface (CIF)"
+	depends on VIDEO_DEV
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
+	depends on V4L_PLATFORM_DRIVERS
+	depends on PM && COMMON_CLK
+	select MEDIA_CONTROLLER
+	select VIDEOBUF2_DMA_CONTIG
+	select V4L2_FWNODE
+	select VIDEO_V4L2_SUBDEV_API
+	help
+	  This is a driver for Rockchip Camera Interface (CIF). It is featured
+	  in many Rockchips SoCs in different variations, such as the PX30
+	  Video Input Processor (VIP, one Digital Video Port (DVP)) or the
+	  RK3568 Video Capture (VICAP, one DVP, one MIPI CSI-2 receiver) unit.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called rockchip-cif.

drivers/media/platform/rockchip/rkcif/Makefile

···
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_VIDEO_ROCKCHIP_CIF) += rockchip-cif.o
+
+rockchip-cif-objs += rkcif-dev.o

drivers/media/platform/rockchip/rkcif/rkcif-common.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Rockchip Camera Interface (CIF) Driver
+ *
+ * Copyright (C) 2018 Rockchip Electronics Co., Ltd.
+ * Copyright (C) 2023 Mehdi Djait <[e-mail]>
+ * Copyright (C) 2025 Michael Riesch <[e-mail]>
+ * Copyright (C) 2025 Collabora, Ltd.
+ */
+
+#ifndef _RKCIF_COMMON_H
+#define _RKCIF_COMMON_H
+
+#include <linux/clk.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+
+#include <media/media-device.h>
+#include <media/media-entity.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
+#include <media/v4l2-subdev.h>
+#include <media/videobuf2-v4l2.h>
+
+#define RKCIF_DRIVER_NAME "rockchip-cif"
+#define RKCIF_CLK_MAX	  4
+
+struct rkcif_remote {
+	struct v4l2_async_connection async_conn;
+	struct v4l2_subdev *sd;
+};
+
+struct rkcif_match_data {
+	const char *const *clks;
+	unsigned int clks_num;
+};
+
+struct rkcif_device {
+	struct device *dev;
+
+	const struct rkcif_match_data *match_data;
+	struct clk_bulk_data clks[RKCIF_CLK_MAX];
+	unsigned int clks_num;
+	struct regmap *grf;
+	struct reset_control *reset;
+	void __iomem *base_addr;
+
+	struct media_device media_dev;
+	struct v4l2_device v4l2_dev;
+	struct v4l2_async_notifier notifier;
+};
+
+#endif

drivers/media/platform/rockchip/rkcif/rkcif-dev.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Rockchip Camera Interface (CIF) Driver
+ *
+ * Copyright (C) 2018 Rockchip Electronics Co., Ltd.
+ * Copyright (C) 2020 Maxime Chevallier <[e-mail]>
+ * Copyright (C) 2023 Mehdi Djait <[e-mail]>
+ * Copyright (C) 2025 Michael Riesch <[e-mail]>
+ * Copyright (C) 2025 Collabora, Ltd.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
+
+#include "rkcif-common.h"
+
+static const char *const px30_vip_clks[] = {
+	"aclk",
+	"hclk",
+	"pclk",
+};
+
+static const struct rkcif_match_data px30_vip_match_data = {
+	.clks = px30_vip_clks,
+	.clks_num = ARRAY_SIZE(px30_vip_clks),
+};
+
+static const char *const rk3568_vicap_clks[] = {
+	"aclk",
+	"hclk",
+	"dclk",
+	"iclk",
+};
+
+static const struct rkcif_match_data rk3568_vicap_match_data = {
+	.clks = rk3568_vicap_clks,
+	.clks_num = ARRAY_SIZE(rk3568_vicap_clks),
+};
+
+static const struct of_device_id rkcif_plat_of_match[] = {
+	{
+		.compatible = "rockchip,px30-vip",
+		.data = &px30_vip_match_data,
+	},
+	{
+		.compatible = "rockchip,rk3568-vicap",
+		.data = &rk3568_vicap_match_data,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, rkcif_plat_of_match);
+
+static int rkcif_register(struct rkcif_device *rkcif)
+{
+	return 0;
+}
+
+static void rkcif_unregister(struct rkcif_device *rkcif)
+{
+}
+
+static int rkcif_notifier_bound(struct v4l2_async_notifier *notifier,
+				struct v4l2_subdev *sd,
+				struct v4l2_async_connection *asd)
+{
+	struct rkcif_remote *remote =
+		container_of(asd, struct rkcif_remote, async_conn);
+
+	remote->sd = sd;
+
+	return 0;
+}
+
+static int rkcif_notifier_complete(struct v4l2_async_notifier *notifier)
+{
+	struct rkcif_device *rkcif =
+		container_of(notifier, struct rkcif_device, notifier);
+
+	return v4l2_device_register_subdev_nodes(&rkcif->v4l2_dev);
+}
+
+static const struct v4l2_async_notifier_operations rkcif_notifier_ops = {
+	.bound = rkcif_notifier_bound,
+	.complete = rkcif_notifier_complete,
+};
+
+static irqreturn_t rkcif_isr(int irq, void *ctx)
+{
+	irqreturn_t ret = IRQ_NONE;
+
+	return ret;
+}
+
+static int rkcif_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rkcif_device *rkcif;
+	int ret, irq;
+
+	rkcif = devm_kzalloc(dev, sizeof(*rkcif), GFP_KERNEL);
+	if (!rkcif)
+		return -ENOMEM;
+
+	rkcif->match_data = of_device_get_match_data(dev);
+	if (!rkcif->match_data)
+		return -ENODEV;
+
+	dev_set_drvdata(dev, rkcif);
+	rkcif->dev = dev;
+
+	rkcif->base_addr = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(rkcif->base_addr))
+		return PTR_ERR(rkcif->base_addr);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_irq(dev, irq, rkcif_isr, IRQF_SHARED,
+			       dev_driver_string(dev), dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to request irq\n");
+
+	if (rkcif->match_data->clks_num > RKCIF_CLK_MAX)
+		return dev_err_probe(dev, -EINVAL, "invalid number of clocks\n");
+
+	rkcif->clks_num = rkcif->match_data->clks_num;
+	for (unsigned int i = 0; i < rkcif->clks_num; i++)
+		rkcif->clks[i].id = rkcif->match_data->clks[i];
+	ret = devm_clk_bulk_get(dev, rkcif->clks_num, rkcif->clks);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to get clocks\n");
+
+	rkcif->reset = devm_reset_control_array_get_exclusive(dev);
+	if (IS_ERR(rkcif->reset))
+		return PTR_ERR(rkcif->reset);
+
+	rkcif->grf = syscon_regmap_lookup_by_phandle(dev->of_node,
+						     "rockchip,grf");
+	if (IS_ERR(rkcif->grf))
+		rkcif->grf = NULL;
+
+	pm_runtime_enable(&pdev->dev);
+
+	rkcif->media_dev.dev = dev;
+	strscpy(rkcif->media_dev.model, RKCIF_DRIVER_NAME,
+		sizeof(rkcif->media_dev.model));
+	media_device_init(&rkcif->media_dev);
+
+	rkcif->v4l2_dev.mdev = &rkcif->media_dev;
+	ret = v4l2_device_register(dev, &rkcif->v4l2_dev);
+	if (ret)
+		goto err_media_dev_cleanup;
+
+	ret = media_device_register(&rkcif->media_dev);
+	if (ret < 0) {
+		dev_err(dev, "failed to register media device: %d\n", ret);
+		goto err_v4l2_dev_unregister;
+	}
+
+	v4l2_async_nf_init(&rkcif->notifier, &rkcif->v4l2_dev);
+	rkcif->notifier.ops = &rkcif_notifier_ops;
+
+	ret = rkcif_register(rkcif);
+	if (ret) {
+		dev_err(dev, "failed to register media entities: %d\n", ret);
+		goto err_notifier_cleanup;
+	}
+
+	ret = v4l2_async_nf_register(&rkcif->notifier);
+	if (ret)
+		goto err_rkcif_unregister;
+
+	return 0;
+
+err_rkcif_unregister:
+	rkcif_unregister(rkcif);
+err_notifier_cleanup:
+	v4l2_async_nf_cleanup(&rkcif->notifier);
+	media_device_unregister(&rkcif->media_dev);
+err_v4l2_dev_unregister:
+	v4l2_device_unregister(&rkcif->v4l2_dev);
+err_media_dev_cleanup:
+	media_device_cleanup(&rkcif->media_dev);
+	pm_runtime_disable(&pdev->dev);
+	return ret;
+}
+
+static void rkcif_remove(struct platform_device *pdev)
+{
+	struct rkcif_device *rkcif = platform_get_drvdata(pdev);
+
+	v4l2_async_nf_unregister(&rkcif->notifier);
+	rkcif_unregister(rkcif);
+	v4l2_async_nf_cleanup(&rkcif->notifier);
+	media_device_unregister(&rkcif->media_dev);
+	v4l2_device_unregister(&rkcif->v4l2_dev);
+	media_device_cleanup(&rkcif->media_dev);
+	pm_runtime_disable(&pdev->dev);
+}
+
+static int rkcif_runtime_suspend(struct device *dev)
+{
+	struct rkcif_device *rkcif = dev_get_drvdata(dev);
+
+	/*
+	 * Reset CIF (CRU, DMA, FIFOs) to allow a clean resume.
+	 * Since this resets the IOMMU too, we cannot issue this reset when
+	 * resuming.
+	 */
+	reset_control_assert(rkcif->reset);
+	udelay(5);
+	reset_control_deassert(rkcif->reset);
+
+	clk_bulk_disable_unprepare(rkcif->clks_num, rkcif->clks);
+
+	return 0;
+}
+
+static int rkcif_runtime_resume(struct device *dev)
+{
+	struct rkcif_device *rkcif = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_bulk_prepare_enable(rkcif->clks_num, rkcif->clks);
+	if (ret) {
+		dev_err(dev, "failed to enable clocks\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops rkcif_plat_pm_ops = {
+	.runtime_suspend = rkcif_runtime_suspend,
+	.runtime_resume = rkcif_runtime_resume,
+};
+
+static struct platform_driver rkcif_plat_drv = {
+	.driver = {
+		   .name = RKCIF_DRIVER_NAME,
+		   .of_match_table = rkcif_plat_of_match,
+		   .pm = &rkcif_plat_pm_ops,
+	},
+	.probe = rkcif_probe,
+	.remove = rkcif_remove,
+};
+module_platform_driver(rkcif_plat_drv);
+
+MODULE_DESCRIPTION("Rockchip Camera Interface (CIF) platform driver");
+MODULE_LICENSE("GPL");