drivers/media/i2c/ccs/ccs-reg-access.c

   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 <linux/unaligned.h>
  13
  14 #include <linux/delay.h>
  15 #include <linux/i2c.h>
  16
  17 #include "ccs.h"
  18 #include "ccs-limits.h"
  19
  20 static 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
  65 static 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
  76 u32 ccs_reg_conv(struct ccs_sensor *sensor, u32 reg, u32 val)
  77 {
  78         struct i2c_client *client = v4l2_get_subdevdata(&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, 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  */
  97 static 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(sensor->regmap, reg, &__val, NULL);
 104         if (rval < 0)
 105                 return rval;
 106
 107         *val = conv ? ccs_reg_conv(sensor, reg, __val) : __val;
 108
 109         return 0;
 110 }
 111
 112 static 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(data);
 135                         break;
 136                 case sizeof(u32):
 137                         *val = get_unaligned_be32(data);
 138                         break;
 139                 default:
 140                         WARN_ON(1);
 141                         return -EINVAL;
 142                 }
 143
 144                 return 0;
 145         }
 146
 147         return -ENOENT;
 148 }
 149
 150 static int
 151 ccs_static_data_read_ro_reg(struct ccs_sensor *sensor, u32 reg, u32 *val)
 152 {
 153         if (!__ccs_static_data_read_ro_reg(sensor->sdata.sensor_read_only_regs,
 154                                            sensor->sdata.num_sensor_read_only_regs,
 155                                            reg, val))
 156                 return 0;
 157
 158         return __ccs_static_data_read_ro_reg(sensor->mdata.module_read_only_regs,
 159                                              sensor->mdata.num_module_read_only_regs,
 160                                              reg, val);
 161 }
 162
 163 static 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, 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
 192 int ccs_read_addr(struct ccs_sensor *sensor, u32 reg, u32 *val)
 193 {
 194         return ccs_read_addr_raw(sensor, reg, val, false, true, true, true);
 195 }
 196
 197 int ccs_read_addr_8only(struct ccs_sensor *sensor, u32 reg, u32 *val)
 198 {
 199         return ccs_read_addr_raw(sensor, reg, val, true, true, true, true);
 200 }
 201
 202 int ccs_read_addr_noconv(struct ccs_sensor *sensor, u32 reg, u32 *val)
 203 {
 204         return ccs_read_addr_raw(sensor, reg, val, false, true, false, true);
 205 }
 206
 207 /*
 208  * Write to a 8/16-bit register.
 209  * Returns zero if successful, or non-zero otherwise.
 210  */
 211 int 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(sensor->regmap, reg, val, &rval))
 225                         fsleep(1000);
 226         } while (rval && --retries);
 227
 228         return rval;
 229 }
 230
 231 #define MAX_WRITE_LEN   32U
 232
 233 int 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(&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(printbuf, regdata, 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(sensor->regmap,
 259                                                          regs->addr + j,
 260                                                          regdata, len);
 261                                 if (rval)
 262                                         fsleep(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 }