summaryrefslogtreecommitdiffstats
path: root/drivers/media/i2c/smiapp/smiapp-regs.c
blob: 1b58b7c6c83937fa24a644d427104f4dbac62f94 (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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
// SPDX-License-Identifier: GPL-2.0-only
/*
 * drivers/media/i2c/smiapp/smiapp-regs.c
 *
 * Generic driver for SMIA/SMIA++ compliant camera modules
 *
 * Copyright (C) 2011--2012 Nokia Corporation
 * Contact: Sakari Ailus <sakari.ailus@iki.fi>
 */

#include <asm/unaligned.h>

#include <linux/delay.h>
#include <linux/i2c.h>

#include "smiapp.h"
#include "smiapp-regs.h"

static uint32_t float_to_u32_mul_1000000(struct i2c_client *client,
					 uint32_t phloat)
{
	int32_t exp;
	uint64_t man;

	if (phloat >= 0x80000000) {
		dev_err(&client->dev, "this is a negative number\n");
		return 0;
	}

	if (phloat == 0x7f800000)
		return ~0; /* Inf. */

	if ((phloat & 0x7f800000) == 0x7f800000) {
		dev_err(&client->dev, "NaN or other special number\n");
		return 0;
	}

	/* Valid cases begin here */
	if (phloat == 0)
		return 0; /* Valid zero */

	if (phloat > 0x4f800000)
		return ~0; /* larger than 4294967295 */

	/*
	 * Unbias exponent (note how phloat is now guaranteed to
	 * have 0 in the high bit)
	 */
	exp = ((int32_t)phloat >> 23) - 127;

	/* Extract mantissa, add missing '1' bit and it's in MHz */
	man = ((phloat & 0x7fffff) | 0x800000) * 1000000ULL;

	if (exp < 0)
		man >>= -exp;
	else
		man <<= exp;

	man >>= 23; /* Remove mantissa bias */

	return man & 0xffffffff;
}


/*
 * Read a 8/16/32-bit i2c register.  The value is returned in 'val'.
 * Returns zero if successful, or non-zero otherwise.
 */
static int ____smiapp_read(struct smiapp_sensor *sensor, u16 reg,
			   u16 len, u32 *val)
{
	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
	struct i2c_msg msg;
	unsigned char data_buf[sizeof(u32)] = { 0 };
	unsigned char offset_buf[sizeof(u16)];
	int r;

	if (len > sizeof(data_buf))
		return -EINVAL;

	msg.addr = client->addr;
	msg.flags = 0;
	msg.len = sizeof(offset_buf);
	msg.buf = offset_buf;
	put_unaligned_be16(reg, offset_buf);

	r = i2c_transfer(client->adapter, &msg, 1);
	if (r != 1) {
		if (r >= 0)
			r = -EBUSY;
		goto err;
	}

	msg.len = len;
	msg.flags = I2C_M_RD;
	msg.buf = &data_buf[sizeof(data_buf) - len];

	r = i2c_transfer(client->adapter, &msg, 1);
	if (r != 1) {
		if (r >= 0)
			r = -EBUSY;
		goto err;
	}

	*val = get_unaligned_be32(data_buf);

	return 0;

err:
	dev_err(&client->dev, "read from offset 0x%x error %d\n", reg, r);

	return r;
}

/* Read a register using 8-bit access only. */
static int ____smiapp_read_8only(struct smiapp_sensor *sensor, u16 reg,
				 u16 len, u32 *val)
{
	unsigned int i;
	int rval;

	*val = 0;

	for (i = 0; i < len; i++) {
		u32 val8;

		rval = ____smiapp_read(sensor, reg + i, 1, &val8);
		if (rval < 0)
			return rval;
		*val |= val8 << ((len - i - 1) << 3);
	}

	return 0;
}

/*
 * Read a 8/16/32-bit i2c register.  The value is returned in 'val'.
 * Returns zero if successful, or non-zero otherwise.
 */
static int __smiapp_read(struct smiapp_sensor *sensor, u32 reg, u32 *val,
			 bool only8)
{
	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
	u8 len = SMIAPP_REG_WIDTH(reg);
	int rval;

	if (len != SMIAPP_REG_8BIT && len != SMIAPP_REG_16BIT
	    && len != SMIAPP_REG_32BIT)
		return -EINVAL;

	if (!only8)
		rval = ____smiapp_read(sensor, SMIAPP_REG_ADDR(reg), len, val);
	else
		rval = ____smiapp_read_8only(sensor, SMIAPP_REG_ADDR(reg), len,
					     val);
	if (rval < 0)
		return rval;

	if (reg & SMIAPP_REG_FLAG_FLOAT)
		*val = float_to_u32_mul_1000000(client, *val);

	return 0;
}

int smiapp_read_no_quirk(struct smiapp_sensor *sensor, u32 reg, u32 *val)
{
	return __smiapp_read(
		sensor, reg, val,
		smiapp_needs_quirk(sensor,
				   SMIAPP_QUIRK_FLAG_8BIT_READ_ONLY));
}

static int smiapp_read_quirk(struct smiapp_sensor *sensor, u32 reg, u32 *val,
			     bool force8)
{
	int rval;

	*val = 0;
	rval = smiapp_call_quirk(sensor, reg_access, false, &reg, val);
	if (rval == -ENOIOCTLCMD)
		return 0;
	if (rval < 0)
		return rval;

	if (force8)
		return __smiapp_read(sensor, reg, val, true);

	return smiapp_read_no_quirk(sensor, reg, val);
}

int smiapp_read(struct smiapp_sensor *sensor, u32 reg, u32 *val)
{
	return smiapp_read_quirk(sensor, reg, val, false);
}

int smiapp_read_8only(struct smiapp_sensor *sensor, u32 reg, u32 *val)
{
	return smiapp_read_quirk(sensor, reg, val, true);
}

int smiapp_write_no_quirk(struct smiapp_sensor *sensor, u32 reg, u32 val)
{
	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
	struct i2c_msg msg;
	unsigned char data[6];
	unsigned int retries;
	u8 len = SMIAPP_REG_WIDTH(reg);
	int r;

	if (len > sizeof(data) - 2)
		return -EINVAL;

	msg.addr = client->addr;
	msg.flags = 0; /* Write */
	msg.len = 2 + len;
	msg.buf = data;

	put_unaligned_be16(SMIAPP_REG_ADDR(reg), data);
	put_unaligned_be32(val << (8 * (sizeof(val) - len)), data + 2);

	for (retries = 0; retries < 5; retries++) {
		/*
		 * Due to unknown reason sensor stops responding. This
		 * loop is a temporaty solution until the root cause
		 * is found.
		 */
		r = i2c_transfer(client->adapter, &msg, 1);
		if (r == 1) {
			if (retries)
				dev_err(&client->dev,
					"sensor i2c stall encountered. retries: %d\n",
					retries);
			return 0;
		}

		usleep_range(2000, 2000);
	}

	dev_err(&client->dev,
		"wrote 0x%x to offset 0x%x error %d\n", val,
		SMIAPP_REG_ADDR(reg), r);

	return r;
}

/*
 * Write to a 8/16-bit register.
 * Returns zero if successful, or non-zero otherwise.
 */
int smiapp_write(struct smiapp_sensor *sensor, u32 reg, u32 val)
{
	int rval;

	rval = smiapp_call_quirk(sensor, reg_access, true, &reg, &val);
	if (rval == -ENOIOCTLCMD)
		return 0;
	if (rval < 0)
		return rval;

	return smiapp_write_no_quirk(sensor, reg, val);
}