drivers/media/platform/renesas/vsp1/vsp1_hgt.c

Source file repositories/reference/linux-study-clean/drivers/media/platform/renesas/vsp1/vsp1_hgt.c

File Facts

System
Linux kernel
Corpus path
drivers/media/platform/renesas/vsp1/vsp1_hgt.c
Extension
.c
Size
5646 bytes
Lines
214
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0+
/*
 * vsp1_hgt.c  --  R-Car VSP1 Histogram Generator 2D
 *
 * Copyright (C) 2016 Renesas Electronics Corporation
 *
 * Contact: Niklas Söderlund (niklas.soderlund@ragnatech.se)
 */

#include <linux/device.h>
#include <linux/gfp.h>

#include <media/v4l2-subdev.h>
#include <media/videobuf2-vmalloc.h>

#include "vsp1.h"
#include "vsp1_dl.h"
#include "vsp1_hgt.h"

#define HGT_DATA_SIZE				((2 +  6 * 32) * 4)

/* -----------------------------------------------------------------------------
 * Device Access
 */

static inline u32 vsp1_hgt_read(struct vsp1_hgt *hgt, u32 reg)
{
	return vsp1_read(hgt->histo.entity.vsp1, reg);
}

static inline void vsp1_hgt_write(struct vsp1_hgt *hgt,
				  struct vsp1_dl_body *dlb, u32 reg, u32 data)
{
	vsp1_dl_body_write(dlb, reg, data);
}

/* -----------------------------------------------------------------------------
 * Frame End Handler
 */

void vsp1_hgt_frame_end(struct vsp1_entity *entity)
{
	struct vsp1_hgt *hgt = to_hgt(&entity->subdev);
	struct vsp1_histogram_buffer *buf;
	unsigned int m;
	unsigned int n;
	u32 *data;

	buf = vsp1_histogram_buffer_get(&hgt->histo);
	if (!buf)
		return;

	data = buf->addr;

	*data++ = vsp1_hgt_read(hgt, VI6_HGT_MAXMIN);
	*data++ = vsp1_hgt_read(hgt, VI6_HGT_SUM);

	for (m = 0; m < 6; ++m)
		for (n = 0; n < 32; ++n)
			*data++ = vsp1_hgt_read(hgt, VI6_HGT_HISTO(m, n));

	vsp1_histogram_buffer_complete(&hgt->histo, buf, HGT_DATA_SIZE);
}

/* -----------------------------------------------------------------------------
 * Controls
 */

#define V4L2_CID_VSP1_HGT_HUE_AREAS	(V4L2_CID_USER_BASE | 0x1001)

static int hgt_hue_areas_try_ctrl(struct v4l2_ctrl *ctrl)
{
	const u8 *values = ctrl->p_new.p_u8;
	unsigned int i;

	/*
	 * The hardware has constraints on the hue area boundaries beyond the
	 * control min, max and step. The values must match one of the following
	 * expressions.
	 *
	 * 0L <= 0U <= 1L <= 1U <= 2L <= 2U <= 3L <= 3U <= 4L <= 4U <= 5L <= 5U
	 * 0U <= 1L <= 1U <= 2L <= 2U <= 3L <= 3U <= 4L <= 4U <= 5L <= 5U <= 0L
	 *
	 * Start by verifying the common part...
	 */
	for (i = 1; i < (HGT_NUM_HUE_AREAS * 2) - 1; ++i) {
		if (values[i] > values[i+1])
			return -EINVAL;
	}

Annotation

Implementation Notes