media: stm32-dcmipp: STM32 DCMIPP camera interface driver

This V4L2 subdev driver enables Digital Camera Memory Interface
Pixel Processor(DCMIPP) of STMicroelectronics STM32 SoC series.
Signed-off-by: Hugues Fruchet <hugues.fruchet@foss.st.com>
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil: remove empty line at end of source]

drivers/media/platform/st/stm32/Kconfig

@@ -16,6 +16,22 @@ config VIDEO_STM32_DCMI
 	  To compile this driver as a module, choose M here: the module
 	  will be called stm32-dcmi.
 
+config VIDEO_STM32_DCMIPP
+	tristate "STM32 Digital Camera Memory Interface Pixel Processor (DCMIPP) support"
+	depends on V4L_PLATFORM_DRIVERS
+	depends on VIDEO_DEV
+	depends on ARCH_STM32 || COMPILE_TEST
+	select MEDIA_CONTROLLER
+	select VIDEOBUF2_DMA_CONTIG
+	select VIDEO_V4L2_SUBDEV_API
+	select V4L2_FWNODE
+	help
+	  This module makes the STM32 Digital Camera Memory Interface
+	  Pixel Processor (DCMIPP) available as a v4l2 device.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called stm32-dcmipp.
+
 # Mem2mem drivers
 config VIDEO_STM32_DMA2D
 	tristate "STM32 Chrom-Art Accelerator (DMA2D)"

drivers/media/platform/st/stm32/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_VIDEO_STM32_DCMI) += stm32-dcmi.o
+obj-$(CONFIG_VIDEO_STM32_DCMIPP) += stm32-dcmipp/
 stm32-dma2d-objs := dma2d/dma2d.o dma2d/dma2d-hw.o
 obj-$(CONFIG_VIDEO_STM32_DMA2D) += stm32-dma2d.o

drivers/media/platform/st/stm32/stm32-dcmipp/Makefile

+# SPDX-License-Identifier: GPL-2.0
+stm32-dcmipp-y := dcmipp-core.o dcmipp-common.o dcmipp-parallel.o dcmipp-byteproc.o dcmipp-bytecap.o
+
+obj-$(CONFIG_VIDEO_STM32_DCMIPP) += stm32-dcmipp.o

drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-common.c

+// 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);
+}

drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-common.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * 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.
+ */
+
+#ifndef _DCMIPP_COMMON_H_
+#define _DCMIPP_COMMON_H_
+
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <media/media-device.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+
+#define DCMIPP_PDEV_NAME "dcmipp"
+
+#define DCMIPP_FRAME_MAX_WIDTH 4096
+#define DCMIPP_FRAME_MAX_HEIGHT 2160
+#define DCMIPP_FRAME_MIN_WIDTH 16
+#define DCMIPP_FRAME_MIN_HEIGHT 16
+
+#define DCMIPP_FMT_WIDTH_DEFAULT  640
+#define DCMIPP_FMT_HEIGHT_DEFAULT 480
+
+#define DCMIPP_COLORSPACE_DEFAULT	V4L2_COLORSPACE_REC709
+#define DCMIPP_YCBCR_ENC_DEFAULT	V4L2_YCBCR_ENC_DEFAULT
+#define DCMIPP_QUANTIZATION_DEFAULT	V4L2_QUANTIZATION_DEFAULT
+#define DCMIPP_XFER_FUNC_DEFAULT	V4L2_XFER_FUNC_DEFAULT
+
+/**
+ * dcmipp_colorimetry_clamp() - Adjust colorimetry parameters
+ *
+ * @fmt:		the pointer to struct v4l2_pix_format or
+ *			struct v4l2_mbus_framefmt
+ *
+ * Entities must check if colorimetry given by the userspace is valid, if not
+ * then set them as DEFAULT
+ */
+#define dcmipp_colorimetry_clamp(fmt)					\
+do {									\
+	if ((fmt)->colorspace == V4L2_COLORSPACE_DEFAULT ||		\
+	    (fmt)->colorspace > V4L2_COLORSPACE_DCI_P3) {		\
+		(fmt)->colorspace = DCMIPP_COLORSPACE_DEFAULT;		\
+		(fmt)->ycbcr_enc = DCMIPP_YCBCR_ENC_DEFAULT;		\
+		(fmt)->quantization = DCMIPP_QUANTIZATION_DEFAULT;	\
+		(fmt)->xfer_func = DCMIPP_XFER_FUNC_DEFAULT;		\
+	}								\
+	if ((fmt)->ycbcr_enc > V4L2_YCBCR_ENC_SMPTE240M)		\
+		(fmt)->ycbcr_enc = DCMIPP_YCBCR_ENC_DEFAULT;		\
+	if ((fmt)->quantization > V4L2_QUANTIZATION_LIM_RANGE)		\
+		(fmt)->quantization = DCMIPP_QUANTIZATION_DEFAULT;	\
+	if ((fmt)->xfer_func > V4L2_XFER_FUNC_SMPTE2084)		\
+		(fmt)->xfer_func = DCMIPP_XFER_FUNC_DEFAULT;		\
+} while (0)
+
+/**
+ * struct dcmipp_ent_device - core struct that represents a node in the topology
+ *
+ * @ent:		the pointer to struct media_entity for the node
+ * @pads:		the list of pads of the node
+ * @bus:		struct v4l2_mbus_config_parallel describing input bus
+ * @bus_type:		type of input bus (parallel or BT656)
+ * @handler:		irq handler dedicated to the subdev
+ * @handler_ret:	value returned by the irq handler
+ * @thread_fn:		threaded irq handler
+ *
+ * The DCMIPP provides a single IRQ line and a IRQ status registers for all
+ * subdevs, hence once the main irq handler (registered at probe time) is
+ * called, it will chain calls to the irq handler of each the subdevs of the
+ * pipelines, using the handler/handler_ret/thread_fn variables.
+ *
+ * Each node of the topology must create a dcmipp_ent_device struct.
+ * Depending on the node it will be of an instance of v4l2_subdev or
+ * video_device struct where both contains a struct media_entity.
+ * Those structures should embedded the dcmipp_ent_device struct through
+ * v4l2_set_subdevdata() and video_set_drvdata() respectivaly, allowing the
+ * dcmipp_ent_device struct to be retrieved from the corresponding struct
+ * media_entity
+ */
+struct dcmipp_ent_device {
+	struct media_entity *ent;
+	struct media_pad *pads;
+
+	/* Parallel input device */
+	struct v4l2_mbus_config_parallel bus;
+	enum v4l2_mbus_type bus_type;
+	irq_handler_t handler;
+	irqreturn_t handler_ret;
+	irq_handler_t thread_fn;
+};
+
+/**
+ * dcmipp_pads_init - initialize pads
+ *
+ * @num_pads:	number of pads to initialize
+ * @pads_flags:	flags to use in each pad
+ *
+ * Helper functions to allocate/initialize pads
+ */
+struct media_pad *dcmipp_pads_init(u16 num_pads,
+				   const unsigned long *pads_flags);
+
+/**
+ * dcmipp_pads_cleanup - free pads
+ *
+ * @pads: pointer to the pads
+ *
+ * Helper function to free the pads initialized with dcmipp_pads_init
+ */
+static inline void dcmipp_pads_cleanup(struct media_pad *pads)
+{
+	kfree(pads);
+}
+
+/**
+ * dcmipp_ent_sd_register - initialize and register a subdev node
+ *
+ * @ved:	the dcmipp_ent_device struct to be initialize
+ * @sd:		the v4l2_subdev struct to be initialize and registered
+ * @v4l2_dev:	the v4l2 device to register the v4l2_subdev
+ * @name:	name of the sub-device. Please notice that the name must be
+ *		unique.
+ * @function:	media entity function defined by MEDIA_ENT_F_* macros
+ * @num_pads:	number of pads to initialize
+ * @pads_flag:	flags to use in each pad
+ * @sd_int_ops:	pointer to &struct v4l2_subdev_internal_ops
+ * @sd_ops:	pointer to &struct v4l2_subdev_ops.
+ * @handler:	func pointer of the irq handler
+ * @thread_fn:	func pointer of the threaded irq handler
+ *
+ * Helper function initialize and register the struct dcmipp_ent_device and
+ * struct v4l2_subdev which represents a subdev node in the topology
+ */
+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);
+
+/**
+ * dcmipp_ent_sd_unregister - cleanup and unregister a subdev node
+ *
+ * @ved:	the dcmipp_ent_device struct to be cleaned up
+ * @sd:		the v4l2_subdev struct to be unregistered
+ *
+ * Helper function cleanup and unregister the struct dcmipp_ent_device and
+ * struct v4l2_subdev which represents a subdev node in the topology
+ */
+void dcmipp_ent_sd_unregister(struct dcmipp_ent_device *ved,
+			      struct v4l2_subdev *sd);
+
+#define reg_write(device, reg, val) \
+	(__reg_write((device)->dev, (device)->regs, (reg), (val)))
+#define reg_read(device, reg) \
+	(__reg_read((device)->dev, (device)->regs, (reg)))
+#define reg_set(device, reg, mask) \
+	(__reg_set((device)->dev, (device)->regs, (reg), (mask)))
+#define reg_clear(device, reg, mask) \
+	(__reg_clear((device)->dev, (device)->regs, (reg), (mask)))
+
+static inline u32 __reg_read(struct device *dev, void __iomem *base, u32 reg)
+{
+	u32 val = readl_relaxed(base + reg);
+
+	dev_dbg(dev, "RD 0x%x %#10.8x\n", reg, val);
+	return val;
+}
+
+static inline void __reg_write(struct device *dev, void __iomem *base, u32 reg,
+			       u32 val)
+{
+	dev_dbg(dev, "WR 0x%x %#10.8x\n", reg, val);
+	writel_relaxed(val, base + reg);
+}
+
+static inline void __reg_set(struct device *dev, void __iomem *base, u32 reg,
+			     u32 mask)
+{
+	dev_dbg(dev, "SET 0x%x %#10.8x\n", reg, mask);
+	__reg_write(dev, base, reg, readl_relaxed(base + reg) | mask);
+}
+
+static inline void __reg_clear(struct device *dev, void __iomem *base, u32 reg,
+			       u32 mask)
+{
+	dev_dbg(dev, "CLR 0x%x %#10.8x\n", reg, mask);
+	__reg_write(dev, base, reg, readl_relaxed(base + reg) & ~mask);
+}
+
+/* DCMIPP subdev init / release entry points */
+struct dcmipp_ent_device *dcmipp_par_ent_init(struct device *dev,
+					      const char *entity_name,
+					      struct v4l2_device *v4l2_dev,
+					      void __iomem *regs);
+void dcmipp_par_ent_release(struct dcmipp_ent_device *ved);
+struct dcmipp_ent_device *
+dcmipp_byteproc_ent_init(struct device *dev, const char *entity_name,
+			 struct v4l2_device *v4l2_dev, void __iomem *regs);
+void dcmipp_byteproc_ent_release(struct dcmipp_ent_device *ved);
+struct dcmipp_ent_device *dcmipp_bytecap_ent_init(struct device *dev,
+						  const char *entity_name,
+						  struct v4l2_device *v4l2_dev,
+						  void __iomem *regs);
+void dcmipp_bytecap_ent_release(struct dcmipp_ent_device *ved);
+
+#endif