summaryrefslogtreecommitdiff
path: root/src/ipa/raspberrypi/cam_helper_imx477.cpp
blob: 25b36bce0daca5d56eb328da6b8b07ea0112b03c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/* SPDX-License-Identifier: BSD-2-Clause */
/*
 * Copyright (C) 2020, Raspberry Pi (Trading) Limited
 *
 * cam_helper_imx477.cpp - camera helper for imx477 sensor
 */

#include <assert.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>

#include "cam_helper.hpp"
#include "md_parser.hpp"

using namespace RPiController;

/* Metadata parser implementation specific to Sony IMX477 sensors. */

class MdParserImx477 : public MdParserSmia
{
public:
	MdParserImx477();
	Status Parse(libcamera::Span<const uint8_t> buffer) override;
	Status GetExposureLines(unsigned int &lines) override;
	Status GetGainCode(unsigned int &gain_code) override;
private:
	/* Offset of the register's value in the metadata block. */
	int reg_offsets_[4];
	/* Value of the register, once read from the metadata block. */
	int reg_values_[4];
};

class CamHelperImx477 : public CamHelper
{
public:
	CamHelperImx477();
	uint32_t GainCode(double gain) const override;
	double Gain(uint32_t gain_code) const override;
	void GetDelays(int &exposure_delay, int &gain_delay,
		       int &vblank_delay) const override;
	bool SensorEmbeddedDataPresent() const override;

private:
	/*
	 * Smallest difference between the frame length and integration time,
	 * in units of lines.
	 */
	static constexpr int frameIntegrationDiff = 22;
};

CamHelperImx477::CamHelperImx477()
	: CamHelper(new MdParserImx477(), frameIntegrationDiff)
{
}

uint32_t CamHelperImx477::GainCode(double gain) const
{
	return static_cast<uint32_t>(1024 - 1024 / gain);
}

double CamHelperImx477::Gain(uint32_t gain_code) const
{
	return 1024.0 / (1024 - gain_code);
}

void CamHelperImx477::GetDelays(int &exposure_delay, int &gain_delay,
				int &vblank_delay) const
{
	exposure_delay = 2;
	gain_delay = 2;
	vblank_delay = 3;
}

bool CamHelperImx477::SensorEmbeddedDataPresent() const
{
	return true;
}

static CamHelper *Create()
{
	return new CamHelperImx477();
}

static RegisterCamHelper reg("imx477", &Create);

/*
 * We care about two gain registers and a pair of exposure registers. Their
 * I2C addresses from the Sony IMX477 datasheet:
 */
#define EXPHI_REG 0x0202
#define EXPLO_REG 0x0203
#define GAINHI_REG 0x0204
#define GAINLO_REG 0x0205

/*
 * Index of each into the reg_offsets and reg_values arrays. Must be in register
 * address order.
 */
#define EXPHI_INDEX 0
#define EXPLO_INDEX 1
#define GAINHI_INDEX 2
#define GAINLO_INDEX 3

MdParserImx477::MdParserImx477()
{
	reg_offsets_[0] = reg_offsets_[1] = reg_offsets_[2] = reg_offsets_[3] = -1;
}

MdParser::Status MdParserImx477::Parse(libcamera::Span<const uint8_t> buffer)
{
	bool try_again = false;

	if (reset_) {
		/*
		 * Search again through the metadata for the gain and exposure
		 * registers.
		 */
		assert(bits_per_pixel_);
		/* Need to be ordered */
		uint32_t regs[4] = {
			EXPHI_REG,
			EXPLO_REG,
			GAINHI_REG,
			GAINLO_REG
		};
		reg_offsets_[0] = reg_offsets_[1] = reg_offsets_[2] = reg_offsets_[3] = -1;
		int ret = static_cast<int>(findRegs(buffer,
						    regs, reg_offsets_, 4));
		/*
		 * > 0 means "worked partially but parse again next time",
		 * < 0 means "hard error".
		 */
		if (ret > 0)
			try_again = true;
		else if (ret < 0)
			return ERROR;
	}

	for (int i = 0; i < 4; i++) {
		if (reg_offsets_[i] == -1)
			continue;

		reg_values_[i] = buffer[reg_offsets_[i]];
	}

	/* Re-parse next time if we were unhappy in some way. */
	reset_ = try_again;

	return OK;
}

MdParser::Status MdParserImx477::GetExposureLines(unsigned int &lines)
{
	if (reg_offsets_[EXPHI_INDEX] == -1 || reg_offsets_[EXPLO_INDEX] == -1)
		return NOTFOUND;

	lines = reg_values_[EXPHI_INDEX] * 256 + reg_values_[EXPLO_INDEX];

	return OK;
}

MdParser::Status MdParserImx477::GetGainCode(unsigned int &gain_code)
{
	if (reg_offsets_[GAINHI_INDEX] == -1 || reg_offsets_[GAINLO_INDEX] == -1)
		return NOTFOUND;

	gain_code = reg_values_[GAINHI_INDEX] * 256 + reg_values_[GAINLO_INDEX];

	return OK;
}