1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/media/i2c/ccs/ccs-reg-access.c
4 *
5 * Generic driver for MIPI CCS/SMIA/SMIA++ compliant camera sensors
6 *
7 * Copyright (C) 2020 Intel Corporation
8 * Copyright (C) 2011--2012 Nokia Corporation
9 * Contact: Sakari Ailus <sakari.ailus@linux.intel.com>
10 */
11
12#include <asm/unaligned.h>
13
14#include <linux/delay.h>
15#include <linux/i2c.h>
16
17#include "ccs.h"
18#include "ccs-limits.h"
19
20static u32 float_to_u32_mul_1000000(struct i2c_client *client, u32 phloat)
21{
22 s32 exp;
23 u64 man;
24
25 if (phloat >= 0x80000000) {
26 dev_err(&client->dev, "this is a negative number\n");
27 return 0;
28 }
29
30 if (phloat == 0x7f800000)
31 return ~0; /* Inf. */
32
33 if ((phloat & 0x7f800000) == 0x7f800000) {
34 dev_err(&client->dev, "NaN or other special number\n");
35 return 0;
36 }
37
38 /* Valid cases begin here */
39 if (phloat == 0)
40 return 0; /* Valid zero */
41
42 if (phloat > 0x4f800000)
43 return ~0; /* larger than 4294967295 */
44
45 /*
46 * Unbias exponent (note how phloat is now guaranteed to
47 * have 0 in the high bit)
48 */
49 exp = ((int32_t)phloat >> 23) - 127;
50
51 /* Extract mantissa, add missing '1' bit and it's in MHz */
52 man = ((phloat & 0x7fffff) | 0x800000) * 1000000ULL;
53
54 if (exp < 0)
55 man >>= -exp;
56 else
57 man <<= exp;
58
59 man >>= 23; /* Remove mantissa bias */
60
61 return man & 0xffffffff;
62}
63
64
65static u32 ireal32_to_u32_mul_1000000(struct i2c_client *client, u32 val)
66{
67 if (val >> 10 > U32_MAX / 15625) {
68 dev_warn(&client->dev, "value %u overflows!\n", val);
69 return U32_MAX;
70 }
71
72 return ((val >> 10) * 15625) +
73 (val & GENMASK(9, 0)) * 15625 / 1024;
74}
75
76u32 ccs_reg_conv(struct ccs_sensor *sensor, u32 reg, u32 val)
77{
78 struct i2c_client *client = v4l2_get_subdevdata(sd: &sensor->src->sd);
79
80 if (reg & CCS_FL_FLOAT_IREAL) {
81 if (CCS_LIM(sensor, CLOCK_CAPA_TYPE_CAPABILITY) &
82 CCS_CLOCK_CAPA_TYPE_CAPABILITY_IREAL)
83 val = ireal32_to_u32_mul_1000000(client, val);
84 else
85 val = float_to_u32_mul_1000000(client, phloat: val);
86 } else if (reg & CCS_FL_IREAL) {
87 val = ireal32_to_u32_mul_1000000(client, val);
88 }
89
90 return val;
91}
92
93/*
94 * Read a 8/16/32-bit i2c register. The value is returned in 'val'.
95 * Returns zero if successful, or non-zero otherwise.
96 */
97static int __ccs_read_addr(struct ccs_sensor *sensor, u32 reg, u32 *val,
98 bool only8, bool conv)
99{
100 u64 __val;
101 int rval;
102
103 rval = cci_read(map: sensor->regmap, reg, val: &__val, NULL);
104 if (rval < 0)
105 return rval;
106
107 *val = conv ? ccs_reg_conv(sensor, reg, val: __val) : __val;
108
109 return 0;
110}
111
112static int __ccs_static_data_read_ro_reg(struct ccs_reg *regs, size_t num_regs,
113 u32 reg, u32 *val)
114{
115 unsigned int width = CCI_REG_WIDTH_BYTES(reg);
116 size_t i;
117
118 for (i = 0; i < num_regs; i++, regs++) {
119 u8 *data;
120
121 if (regs->addr + regs->len < CCS_REG_ADDR(reg) + width)
122 continue;
123
124 if (regs->addr > CCS_REG_ADDR(reg))
125 break;
126
127 data = &regs->value[CCS_REG_ADDR(reg) - regs->addr];
128
129 switch (width) {
130 case sizeof(u8):
131 *val = *data;
132 break;
133 case sizeof(u16):
134 *val = get_unaligned_be16(p: data);
135 break;
136 case sizeof(u32):
137 *val = get_unaligned_be32(p: data);
138 break;
139 default:
140 WARN_ON(1);
141 return -EINVAL;
142 }
143
144 return 0;
145 }
146
147 return -ENOENT;
148}
149
150static int
151ccs_static_data_read_ro_reg(struct ccs_sensor *sensor, u32 reg, u32 *val)
152{
153 if (!__ccs_static_data_read_ro_reg(regs: sensor->sdata.sensor_read_only_regs,
154 num_regs: sensor->sdata.num_sensor_read_only_regs,
155 reg, val))
156 return 0;
157
158 return __ccs_static_data_read_ro_reg(regs: sensor->mdata.module_read_only_regs,
159 num_regs: sensor->mdata.num_module_read_only_regs,
160 reg, val);
161}
162
163static int ccs_read_addr_raw(struct ccs_sensor *sensor, u32 reg, u32 *val,
164 bool force8, bool quirk, bool conv, bool data)
165{
166 int rval;
167
168 if (data) {
169 rval = ccs_static_data_read_ro_reg(sensor, reg, val);
170 if (!rval)
171 return 0;
172 }
173
174 if (quirk) {
175 *val = 0;
176 rval = ccs_call_quirk(sensor, reg_access, false, &reg, val);
177 if (rval == -ENOIOCTLCMD)
178 return 0;
179 if (rval < 0)
180 return rval;
181
182 if (force8)
183 return __ccs_read_addr(sensor, reg, val, only8: true, conv);
184 }
185
186 return __ccs_read_addr(sensor, reg, val,
187 ccs_needs_quirk(sensor,
188 CCS_QUIRK_FLAG_8BIT_READ_ONLY),
189 conv);
190}
191
192int ccs_read_addr(struct ccs_sensor *sensor, u32 reg, u32 *val)
193{
194 return ccs_read_addr_raw(sensor, reg, val, force8: false, quirk: true, conv: true, data: true);
195}
196
197int ccs_read_addr_8only(struct ccs_sensor *sensor, u32 reg, u32 *val)
198{
199 return ccs_read_addr_raw(sensor, reg, val, force8: true, quirk: true, conv: true, data: true);
200}
201
202int ccs_read_addr_noconv(struct ccs_sensor *sensor, u32 reg, u32 *val)
203{
204 return ccs_read_addr_raw(sensor, reg, val, force8: false, quirk: true, conv: false, data: true);
205}
206
207/*
208 * Write to a 8/16-bit register.
209 * Returns zero if successful, or non-zero otherwise.
210 */
211int ccs_write_addr(struct ccs_sensor *sensor, u32 reg, u32 val)
212{
213 unsigned int retries = 10;
214 int rval;
215
216 rval = ccs_call_quirk(sensor, reg_access, true, &reg, &val);
217 if (rval == -ENOIOCTLCMD)
218 return 0;
219 if (rval < 0)
220 return rval;
221
222 rval = 0;
223 do {
224 if (cci_write(map: sensor->regmap, reg, val, err: &rval))
225 fsleep(usecs: 1000);
226 } while (rval && --retries);
227
228 return rval;
229}
230
231#define MAX_WRITE_LEN 32U
232
233int ccs_write_data_regs(struct ccs_sensor *sensor, struct ccs_reg *regs,
234 size_t num_regs)
235{
236 struct i2c_client *client = v4l2_get_subdevdata(sd: &sensor->src->sd);
237 size_t i;
238
239 for (i = 0; i < num_regs; i++, regs++) {
240 unsigned char *regdata = regs->value;
241 unsigned int j;
242 int len;
243
244 for (j = 0; j < regs->len; j += len, regdata += len) {
245 char printbuf[(MAX_WRITE_LEN << 1) +
246 1 /* \0 */] = { 0 };
247 unsigned int retries = 10;
248 int rval;
249
250 len = min(regs->len - j, MAX_WRITE_LEN);
251
252 bin2hex(dst: printbuf, src: regdata, count: len);
253 dev_dbg(&client->dev,
254 "writing msr reg 0x%4.4x value 0x%s\n",
255 regs->addr + j, printbuf);
256
257 do {
258 rval = regmap_bulk_write(map: sensor->regmap,
259 reg: regs->addr + j,
260 val: regdata, val_count: len);
261 if (rval)
262 fsleep(usecs: 1000);
263 } while (rval && --retries);
264
265 if (rval) {
266 dev_err(&client->dev,
267 "error writing %u octets to address 0x%4.4x\n",
268 len, regs->addr + j);
269 return rval;
270 }
271 }
272 }
273
274 return 0;
275}
276

source code of linux/drivers/media/i2c/ccs/ccs-reg-access.c