drivers/iio/magnetometer/ak8975.c

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This source file includes following definitions.
ak8975_raw_to_gauss
ak8963_09911_raw_to_gauss
ak09912_raw_to_gauss
ak8975_power_on
ak8975_power_off
ak8975_who_i_am
ak8975_set_mode
ak8975_irq_handler
ak8975_setup_irq
ak8975_setup
wait_conversion_complete_gpio
wait_conversion_complete_polled
wait_conversion_complete_interrupt
ak8975_start_read_axis
ak8975_read_axis
ak8975_read_raw
ak8975_get_mount_matrix
ak8975_match_acpi_device
ak8975_fill_buffer
ak8975_handle_trigger
ak8975_probe
ak8975_remove
ak8975_runtime_suspend
ak8975_runtime_resume
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * A sensor driver for the magnetometer AK8975.
   4  *
   5  * Magnetic compass sensor driver for monitoring magnetic flux information.
   6  *
   7  * Copyright (c) 2010, NVIDIA Corporation.
   8  */
   9 
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/i2c.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/err.h>
  16 #include <linux/mutex.h>
  17 #include <linux/delay.h>
  18 #include <linux/bitops.h>
  19 #include <linux/gpio.h>
  20 #include <linux/of_gpio.h>
  21 #include <linux/acpi.h>
  22 #include <linux/regulator/consumer.h>
  23 #include <linux/pm_runtime.h>
  24 
  25 #include <linux/iio/iio.h>
  26 #include <linux/iio/sysfs.h>
  27 #include <linux/iio/buffer.h>
  28 #include <linux/iio/trigger.h>
  29 #include <linux/iio/trigger_consumer.h>
  30 #include <linux/iio/triggered_buffer.h>
  31 
  32 #include <linux/iio/magnetometer/ak8975.h>
  33 
  34 /*
  35  * Register definitions, as well as various shifts and masks to get at the
  36  * individual fields of the registers.
  37  */
  38 #define AK8975_REG_WIA                  0x00
  39 #define AK8975_DEVICE_ID                0x48
  40 
  41 #define AK8975_REG_INFO                 0x01
  42 
  43 #define AK8975_REG_ST1                  0x02
  44 #define AK8975_REG_ST1_DRDY_SHIFT       0
  45 #define AK8975_REG_ST1_DRDY_MASK        (1 << AK8975_REG_ST1_DRDY_SHIFT)
  46 
  47 #define AK8975_REG_HXL                  0x03
  48 #define AK8975_REG_HXH                  0x04
  49 #define AK8975_REG_HYL                  0x05
  50 #define AK8975_REG_HYH                  0x06
  51 #define AK8975_REG_HZL                  0x07
  52 #define AK8975_REG_HZH                  0x08
  53 #define AK8975_REG_ST2                  0x09
  54 #define AK8975_REG_ST2_DERR_SHIFT       2
  55 #define AK8975_REG_ST2_DERR_MASK        (1 << AK8975_REG_ST2_DERR_SHIFT)
  56 
  57 #define AK8975_REG_ST2_HOFL_SHIFT       3
  58 #define AK8975_REG_ST2_HOFL_MASK        (1 << AK8975_REG_ST2_HOFL_SHIFT)
  59 
  60 #define AK8975_REG_CNTL                 0x0A
  61 #define AK8975_REG_CNTL_MODE_SHIFT      0
  62 #define AK8975_REG_CNTL_MODE_MASK       (0xF << AK8975_REG_CNTL_MODE_SHIFT)
  63 #define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00
  64 #define AK8975_REG_CNTL_MODE_ONCE       0x01
  65 #define AK8975_REG_CNTL_MODE_SELF_TEST  0x08
  66 #define AK8975_REG_CNTL_MODE_FUSE_ROM   0x0F
  67 
  68 #define AK8975_REG_RSVC                 0x0B
  69 #define AK8975_REG_ASTC                 0x0C
  70 #define AK8975_REG_TS1                  0x0D
  71 #define AK8975_REG_TS2                  0x0E
  72 #define AK8975_REG_I2CDIS               0x0F
  73 #define AK8975_REG_ASAX                 0x10
  74 #define AK8975_REG_ASAY                 0x11
  75 #define AK8975_REG_ASAZ                 0x12
  76 
  77 #define AK8975_MAX_REGS                 AK8975_REG_ASAZ
  78 
  79 /*
  80  * AK09912 Register definitions
  81  */
  82 #define AK09912_REG_WIA1                0x00
  83 #define AK09912_REG_WIA2                0x01
  84 #define AK09912_DEVICE_ID               0x04
  85 #define AK09911_DEVICE_ID               0x05
  86 
  87 #define AK09911_REG_INFO1               0x02
  88 #define AK09911_REG_INFO2               0x03
  89 
  90 #define AK09912_REG_ST1                 0x10
  91 
  92 #define AK09912_REG_ST1_DRDY_SHIFT      0
  93 #define AK09912_REG_ST1_DRDY_MASK       (1 << AK09912_REG_ST1_DRDY_SHIFT)
  94 
  95 #define AK09912_REG_HXL                 0x11
  96 #define AK09912_REG_HXH                 0x12
  97 #define AK09912_REG_HYL                 0x13
  98 #define AK09912_REG_HYH                 0x14
  99 #define AK09912_REG_HZL                 0x15
 100 #define AK09912_REG_HZH                 0x16
 101 #define AK09912_REG_TMPS                0x17
 102 
 103 #define AK09912_REG_ST2                 0x18
 104 #define AK09912_REG_ST2_HOFL_SHIFT      3
 105 #define AK09912_REG_ST2_HOFL_MASK       (1 << AK09912_REG_ST2_HOFL_SHIFT)
 106 
 107 #define AK09912_REG_CNTL1               0x30
 108 
 109 #define AK09912_REG_CNTL2               0x31
 110 #define AK09912_REG_CNTL_MODE_POWER_DOWN        0x00
 111 #define AK09912_REG_CNTL_MODE_ONCE      0x01
 112 #define AK09912_REG_CNTL_MODE_SELF_TEST 0x10
 113 #define AK09912_REG_CNTL_MODE_FUSE_ROM  0x1F
 114 #define AK09912_REG_CNTL2_MODE_SHIFT    0
 115 #define AK09912_REG_CNTL2_MODE_MASK     (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)
 116 
 117 #define AK09912_REG_CNTL3               0x32
 118 
 119 #define AK09912_REG_TS1                 0x33
 120 #define AK09912_REG_TS2                 0x34
 121 #define AK09912_REG_TS3                 0x35
 122 #define AK09912_REG_I2CDIS              0x36
 123 #define AK09912_REG_TS4                 0x37
 124 
 125 #define AK09912_REG_ASAX                0x60
 126 #define AK09912_REG_ASAY                0x61
 127 #define AK09912_REG_ASAZ                0x62
 128 
 129 #define AK09912_MAX_REGS                AK09912_REG_ASAZ
 130 
 131 /*
 132  * Miscellaneous values.
 133  */
 134 #define AK8975_MAX_CONVERSION_TIMEOUT   500
 135 #define AK8975_CONVERSION_DONE_POLL_TIME 10
 136 #define AK8975_DATA_READY_TIMEOUT       ((100*HZ)/1000)
 137 
 138 /*
 139  * Precalculate scale factor (in Gauss units) for each axis and
 140  * store in the device data.
 141  *
 142  * This scale factor is axis-dependent, and is derived from 3 calibration
 143  * factors ASA(x), ASA(y), and ASA(z).
 144  *
 145  * These ASA values are read from the sensor device at start of day, and
 146  * cached in the device context struct.
 147  *
 148  * Adjusting the flux value with the sensitivity adjustment value should be
 149  * done via the following formula:
 150  *
 151  * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )
 152  * where H is the raw value, ASA is the sensitivity adjustment, and Hadj
 153  * is the resultant adjusted value.
 154  *
 155  * We reduce the formula to:
 156  *
 157  * Hadj = H * (ASA + 128) / 256
 158  *
 159  * H is in the range of -4096 to 4095.  The magnetometer has a range of
 160  * +-1229uT.  To go from the raw value to uT is:
 161  *
 162  * HuT = H * 1229/4096, or roughly, 3/10.
 163  *
 164  * Since 1uT = 0.01 gauss, our final scale factor becomes:
 165  *
 166  * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100
 167  * Hadj = H * ((ASA + 128) * 0.003) / 256
 168  *
 169  * Since ASA doesn't change, we cache the resultant scale factor into the
 170  * device context in ak8975_setup().
 171  *
 172  * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we
 173  * multiply the stored scale value by 1e6.
 174  */
 175 static long ak8975_raw_to_gauss(u16 data)
 176 {
 177         return (((long)data + 128) * 3000) / 256;
 178 }
 179 
 180 /*
 181  * For AK8963 and AK09911, same calculation, but the device is less sensitive:
 182  *
 183  * H is in the range of +-8190.  The magnetometer has a range of
 184  * +-4912uT.  To go from the raw value to uT is:
 185  *
 186  * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.
 187  */
 188 
 189 static long ak8963_09911_raw_to_gauss(u16 data)
 190 {
 191         return (((long)data + 128) * 6000) / 256;
 192 }
 193 
 194 /*
 195  * For AK09912, same calculation, except the device is more sensitive:
 196  *
 197  * H is in the range of -32752 to 32752.  The magnetometer has a range of
 198  * +-4912uT.  To go from the raw value to uT is:
 199  *
 200  * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.
 201  */
 202 static long ak09912_raw_to_gauss(u16 data)
 203 {
 204         return (((long)data + 128) * 1500) / 256;
 205 }
 206 
 207 /* Compatible Asahi Kasei Compass parts */
 208 enum asahi_compass_chipset {
 209         AK8975,
 210         AK8963,
 211         AK09911,
 212         AK09912,
 213         AK_MAX_TYPE
 214 };
 215 
 216 enum ak_ctrl_reg_addr {
 217         ST1,
 218         ST2,
 219         CNTL,
 220         ASA_BASE,
 221         MAX_REGS,
 222         REGS_END,
 223 };
 224 
 225 enum ak_ctrl_reg_mask {
 226         ST1_DRDY,
 227         ST2_HOFL,
 228         ST2_DERR,
 229         CNTL_MODE,
 230         MASK_END,
 231 };
 232 
 233 enum ak_ctrl_mode {
 234         POWER_DOWN,
 235         MODE_ONCE,
 236         SELF_TEST,
 237         FUSE_ROM,
 238         MODE_END,
 239 };
 240 
 241 struct ak_def {
 242         enum asahi_compass_chipset type;
 243         long (*raw_to_gauss)(u16 data);
 244         u16 range;
 245         u8 ctrl_regs[REGS_END];
 246         u8 ctrl_masks[MASK_END];
 247         u8 ctrl_modes[MODE_END];
 248         u8 data_regs[3];
 249 };
 250 
 251 static const struct ak_def ak_def_array[AK_MAX_TYPE] = {
 252         {
 253                 .type = AK8975,
 254                 .raw_to_gauss = ak8975_raw_to_gauss,
 255                 .range = 4096,
 256                 .ctrl_regs = {
 257                         AK8975_REG_ST1,
 258                         AK8975_REG_ST2,
 259                         AK8975_REG_CNTL,
 260                         AK8975_REG_ASAX,
 261                         AK8975_MAX_REGS},
 262                 .ctrl_masks = {
 263                         AK8975_REG_ST1_DRDY_MASK,
 264                         AK8975_REG_ST2_HOFL_MASK,
 265                         AK8975_REG_ST2_DERR_MASK,
 266                         AK8975_REG_CNTL_MODE_MASK},
 267                 .ctrl_modes = {
 268                         AK8975_REG_CNTL_MODE_POWER_DOWN,
 269                         AK8975_REG_CNTL_MODE_ONCE,
 270                         AK8975_REG_CNTL_MODE_SELF_TEST,
 271                         AK8975_REG_CNTL_MODE_FUSE_ROM},
 272                 .data_regs = {
 273                         AK8975_REG_HXL,
 274                         AK8975_REG_HYL,
 275                         AK8975_REG_HZL},
 276         },
 277         {
 278                 .type = AK8963,
 279                 .raw_to_gauss = ak8963_09911_raw_to_gauss,
 280                 .range = 8190,
 281                 .ctrl_regs = {
 282                         AK8975_REG_ST1,
 283                         AK8975_REG_ST2,
 284                         AK8975_REG_CNTL,
 285                         AK8975_REG_ASAX,
 286                         AK8975_MAX_REGS},
 287                 .ctrl_masks = {
 288                         AK8975_REG_ST1_DRDY_MASK,
 289                         AK8975_REG_ST2_HOFL_MASK,
 290                         0,
 291                         AK8975_REG_CNTL_MODE_MASK},
 292                 .ctrl_modes = {
 293                         AK8975_REG_CNTL_MODE_POWER_DOWN,
 294                         AK8975_REG_CNTL_MODE_ONCE,
 295                         AK8975_REG_CNTL_MODE_SELF_TEST,
 296                         AK8975_REG_CNTL_MODE_FUSE_ROM},
 297                 .data_regs = {
 298                         AK8975_REG_HXL,
 299                         AK8975_REG_HYL,
 300                         AK8975_REG_HZL},
 301         },
 302         {
 303                 .type = AK09911,
 304                 .raw_to_gauss = ak8963_09911_raw_to_gauss,
 305                 .range = 8192,
 306                 .ctrl_regs = {
 307                         AK09912_REG_ST1,
 308                         AK09912_REG_ST2,
 309                         AK09912_REG_CNTL2,
 310                         AK09912_REG_ASAX,
 311                         AK09912_MAX_REGS},
 312                 .ctrl_masks = {
 313                         AK09912_REG_ST1_DRDY_MASK,
 314                         AK09912_REG_ST2_HOFL_MASK,
 315                         0,
 316                         AK09912_REG_CNTL2_MODE_MASK},
 317                 .ctrl_modes = {
 318                         AK09912_REG_CNTL_MODE_POWER_DOWN,
 319                         AK09912_REG_CNTL_MODE_ONCE,
 320                         AK09912_REG_CNTL_MODE_SELF_TEST,
 321                         AK09912_REG_CNTL_MODE_FUSE_ROM},
 322                 .data_regs = {
 323                         AK09912_REG_HXL,
 324                         AK09912_REG_HYL,
 325                         AK09912_REG_HZL},
 326         },
 327         {
 328                 .type = AK09912,
 329                 .raw_to_gauss = ak09912_raw_to_gauss,
 330                 .range = 32752,
 331                 .ctrl_regs = {
 332                         AK09912_REG_ST1,
 333                         AK09912_REG_ST2,
 334                         AK09912_REG_CNTL2,
 335                         AK09912_REG_ASAX,
 336                         AK09912_MAX_REGS},
 337                 .ctrl_masks = {
 338                         AK09912_REG_ST1_DRDY_MASK,
 339                         AK09912_REG_ST2_HOFL_MASK,
 340                         0,
 341                         AK09912_REG_CNTL2_MODE_MASK},
 342                 .ctrl_modes = {
 343                         AK09912_REG_CNTL_MODE_POWER_DOWN,
 344                         AK09912_REG_CNTL_MODE_ONCE,
 345                         AK09912_REG_CNTL_MODE_SELF_TEST,
 346                         AK09912_REG_CNTL_MODE_FUSE_ROM},
 347                 .data_regs = {
 348                         AK09912_REG_HXL,
 349                         AK09912_REG_HYL,
 350                         AK09912_REG_HZL},
 351         }
 352 };
 353 
 354 /*
 355  * Per-instance context data for the device.
 356  */
 357 struct ak8975_data {
 358         struct i2c_client       *client;
 359         const struct ak_def     *def;
 360         struct mutex            lock;
 361         u8                      asa[3];
 362         long                    raw_to_gauss[3];
 363         int                     eoc_gpio;
 364         int                     eoc_irq;
 365         wait_queue_head_t       data_ready_queue;
 366         unsigned long           flags;
 367         u8                      cntl_cache;
 368         struct iio_mount_matrix orientation;
 369         struct regulator        *vdd;
 370         struct regulator        *vid;
 371 };
 372 
 373 /* Enable attached power regulator if any. */
 374 static int ak8975_power_on(const struct ak8975_data *data)
 375 {
 376         int ret;
 377 
 378         ret = regulator_enable(data->vdd);
 379         if (ret) {
 380                 dev_warn(&data->client->dev,
 381                          "Failed to enable specified Vdd supply\n");
 382                 return ret;
 383         }
 384         ret = regulator_enable(data->vid);
 385         if (ret) {
 386                 dev_warn(&data->client->dev,
 387                          "Failed to enable specified Vid supply\n");
 388                 return ret;
 389         }
 390         /*
 391          * According to the datasheet the power supply rise time i 200us
 392          * and the minimum wait time before mode setting is 100us, in
 393          * total 300 us. Add some margin and say minimum 500us here.
 394          */
 395         usleep_range(500, 1000);
 396         return 0;
 397 }
 398 
 399 /* Disable attached power regulator if any. */
 400 static void ak8975_power_off(const struct ak8975_data *data)
 401 {
 402         regulator_disable(data->vid);
 403         regulator_disable(data->vdd);
 404 }
 405 
 406 /*
 407  * Return 0 if the i2c device is the one we expect.
 408  * return a negative error number otherwise
 409  */
 410 static int ak8975_who_i_am(struct i2c_client *client,
 411                            enum asahi_compass_chipset type)
 412 {
 413         u8 wia_val[2];
 414         int ret;
 415 
 416         /*
 417          * Signature for each device:
 418          * Device   |  WIA1      |  WIA2
 419          * AK09912  |  DEVICE_ID |  AK09912_DEVICE_ID
 420          * AK09911  |  DEVICE_ID |  AK09911_DEVICE_ID
 421          * AK8975   |  DEVICE_ID |  NA
 422          * AK8963   |  DEVICE_ID |  NA
 423          */
 424         ret = i2c_smbus_read_i2c_block_data_or_emulated(
 425                         client, AK09912_REG_WIA1, 2, wia_val);
 426         if (ret < 0) {
 427                 dev_err(&client->dev, "Error reading WIA\n");
 428                 return ret;
 429         }
 430 
 431         if (wia_val[0] != AK8975_DEVICE_ID)
 432                 return -ENODEV;
 433 
 434         switch (type) {
 435         case AK8975:
 436         case AK8963:
 437                 return 0;
 438         case AK09911:
 439                 if (wia_val[1] == AK09911_DEVICE_ID)
 440                         return 0;
 441                 break;
 442         case AK09912:
 443                 if (wia_val[1] == AK09912_DEVICE_ID)
 444                         return 0;
 445                 break;
 446         default:
 447                 dev_err(&client->dev, "Type %d unknown\n", type);
 448         }
 449         return -ENODEV;
 450 }
 451 
 452 /*
 453  * Helper function to write to CNTL register.
 454  */
 455 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)
 456 {
 457         u8 regval;
 458         int ret;
 459 
 460         regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |
 461                  data->def->ctrl_modes[mode];
 462         ret = i2c_smbus_write_byte_data(data->client,
 463                                         data->def->ctrl_regs[CNTL], regval);
 464         if (ret < 0) {
 465                 return ret;
 466         }
 467         data->cntl_cache = regval;
 468         /* After mode change wait atleast 100us */
 469         usleep_range(100, 500);
 470 
 471         return 0;
 472 }
 473 
 474 /*
 475  * Handle data ready irq
 476  */
 477 static irqreturn_t ak8975_irq_handler(int irq, void *data)
 478 {
 479         struct ak8975_data *ak8975 = data;
 480 
 481         set_bit(0, &ak8975->flags);
 482         wake_up(&ak8975->data_ready_queue);
 483 
 484         return IRQ_HANDLED;
 485 }
 486 
 487 /*
 488  * Install data ready interrupt handler
 489  */
 490 static int ak8975_setup_irq(struct ak8975_data *data)
 491 {
 492         struct i2c_client *client = data->client;
 493         int rc;
 494         int irq;
 495 
 496         init_waitqueue_head(&data->data_ready_queue);
 497         clear_bit(0, &data->flags);
 498         if (client->irq)
 499                 irq = client->irq;
 500         else
 501                 irq = gpio_to_irq(data->eoc_gpio);
 502 
 503         rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
 504                               IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 505                               dev_name(&client->dev), data);
 506         if (rc < 0) {
 507                 dev_err(&client->dev,
 508                         "irq %d request failed, (gpio %d): %d\n",
 509                         irq, data->eoc_gpio, rc);
 510                 return rc;
 511         }
 512 
 513         data->eoc_irq = irq;
 514 
 515         return rc;
 516 }
 517 
 518 
 519 /*
 520  * Perform some start-of-day setup, including reading the asa calibration
 521  * values and caching them.
 522  */
 523 static int ak8975_setup(struct i2c_client *client)
 524 {
 525         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 526         struct ak8975_data *data = iio_priv(indio_dev);
 527         int ret;
 528 
 529         /* Write the fused rom access mode. */
 530         ret = ak8975_set_mode(data, FUSE_ROM);
 531         if (ret < 0) {
 532                 dev_err(&client->dev, "Error in setting fuse access mode\n");
 533                 return ret;
 534         }
 535 
 536         /* Get asa data and store in the device data. */
 537         ret = i2c_smbus_read_i2c_block_data_or_emulated(
 538                         client, data->def->ctrl_regs[ASA_BASE],
 539                         3, data->asa);
 540         if (ret < 0) {
 541                 dev_err(&client->dev, "Not able to read asa data\n");
 542                 return ret;
 543         }
 544 
 545         /* After reading fuse ROM data set power-down mode */
 546         ret = ak8975_set_mode(data, POWER_DOWN);
 547         if (ret < 0) {
 548                 dev_err(&client->dev, "Error in setting power-down mode\n");
 549                 return ret;
 550         }
 551 
 552         if (data->eoc_gpio > 0 || client->irq > 0) {
 553                 ret = ak8975_setup_irq(data);
 554                 if (ret < 0) {
 555                         dev_err(&client->dev,
 556                                 "Error setting data ready interrupt\n");
 557                         return ret;
 558                 }
 559         }
 560 
 561         data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);
 562         data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);
 563         data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);
 564 
 565         return 0;
 566 }
 567 
 568 static int wait_conversion_complete_gpio(struct ak8975_data *data)
 569 {
 570         struct i2c_client *client = data->client;
 571         u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
 572         int ret;
 573 
 574         /* Wait for the conversion to complete. */
 575         while (timeout_ms) {
 576                 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
 577                 if (gpio_get_value(data->eoc_gpio))
 578                         break;
 579                 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
 580         }
 581         if (!timeout_ms) {
 582                 dev_err(&client->dev, "Conversion timeout happened\n");
 583                 return -EINVAL;
 584         }
 585 
 586         ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]);
 587         if (ret < 0)
 588                 dev_err(&client->dev, "Error in reading ST1\n");
 589 
 590         return ret;
 591 }
 592 
 593 static int wait_conversion_complete_polled(struct ak8975_data *data)
 594 {
 595         struct i2c_client *client = data->client;
 596         u8 read_status;
 597         u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
 598         int ret;
 599 
 600         /* Wait for the conversion to complete. */
 601         while (timeout_ms) {
 602                 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
 603                 ret = i2c_smbus_read_byte_data(client,
 604                                                data->def->ctrl_regs[ST1]);
 605                 if (ret < 0) {
 606                         dev_err(&client->dev, "Error in reading ST1\n");
 607                         return ret;
 608                 }
 609                 read_status = ret;
 610                 if (read_status)
 611                         break;
 612                 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
 613         }
 614         if (!timeout_ms) {
 615                 dev_err(&client->dev, "Conversion timeout happened\n");
 616                 return -EINVAL;
 617         }
 618 
 619         return read_status;
 620 }
 621 
 622 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */
 623 static int wait_conversion_complete_interrupt(struct ak8975_data *data)
 624 {
 625         int ret;
 626 
 627         ret = wait_event_timeout(data->data_ready_queue,
 628                                  test_bit(0, &data->flags),
 629                                  AK8975_DATA_READY_TIMEOUT);
 630         clear_bit(0, &data->flags);
 631 
 632         return ret > 0 ? 0 : -ETIME;
 633 }
 634 
 635 static int ak8975_start_read_axis(struct ak8975_data *data,
 636                                   const struct i2c_client *client)
 637 {
 638         /* Set up the device for taking a sample. */
 639         int ret = ak8975_set_mode(data, MODE_ONCE);
 640 
 641         if (ret < 0) {
 642                 dev_err(&client->dev, "Error in setting operating mode\n");
 643                 return ret;
 644         }
 645 
 646         /* Wait for the conversion to complete. */
 647         if (data->eoc_irq)
 648                 ret = wait_conversion_complete_interrupt(data);
 649         else if (gpio_is_valid(data->eoc_gpio))
 650                 ret = wait_conversion_complete_gpio(data);
 651         else
 652                 ret = wait_conversion_complete_polled(data);
 653         if (ret < 0)
 654                 return ret;
 655 
 656         /* This will be executed only for non-interrupt based waiting case */
 657         if (ret & data->def->ctrl_masks[ST1_DRDY]) {
 658                 ret = i2c_smbus_read_byte_data(client,
 659                                                data->def->ctrl_regs[ST2]);
 660                 if (ret < 0) {
 661                         dev_err(&client->dev, "Error in reading ST2\n");
 662                         return ret;
 663                 }
 664                 if (ret & (data->def->ctrl_masks[ST2_DERR] |
 665                            data->def->ctrl_masks[ST2_HOFL])) {
 666                         dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
 667                         return -EINVAL;
 668                 }
 669         }
 670 
 671         return 0;
 672 }
 673 
 674 /* Retrieve raw flux value for one of the x, y, or z axis.  */
 675 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
 676 {
 677         struct ak8975_data *data = iio_priv(indio_dev);
 678         const struct i2c_client *client = data->client;
 679         const struct ak_def *def = data->def;
 680         __le16 rval;
 681         u16 buff;
 682         int ret;
 683 
 684         pm_runtime_get_sync(&data->client->dev);
 685 
 686         mutex_lock(&data->lock);
 687 
 688         ret = ak8975_start_read_axis(data, client);
 689         if (ret)
 690                 goto exit;
 691 
 692         ret = i2c_smbus_read_i2c_block_data_or_emulated(
 693                         client, def->data_regs[index],
 694                         sizeof(rval), (u8*)&rval);
 695         if (ret < 0)
 696                 goto exit;
 697 
 698         mutex_unlock(&data->lock);
 699 
 700         pm_runtime_mark_last_busy(&data->client->dev);
 701         pm_runtime_put_autosuspend(&data->client->dev);
 702 
 703         /* Swap bytes and convert to valid range. */
 704         buff = le16_to_cpu(rval);
 705         *val = clamp_t(s16, buff, -def->range, def->range);
 706         return IIO_VAL_INT;
 707 
 708 exit:
 709         mutex_unlock(&data->lock);
 710         dev_err(&client->dev, "Error in reading axis\n");
 711         return ret;
 712 }
 713 
 714 static int ak8975_read_raw(struct iio_dev *indio_dev,
 715                            struct iio_chan_spec const *chan,
 716                            int *val, int *val2,
 717                            long mask)
 718 {
 719         struct ak8975_data *data = iio_priv(indio_dev);
 720 
 721         switch (mask) {
 722         case IIO_CHAN_INFO_RAW:
 723                 return ak8975_read_axis(indio_dev, chan->address, val);
 724         case IIO_CHAN_INFO_SCALE:
 725                 *val = 0;
 726                 *val2 = data->raw_to_gauss[chan->address];
 727                 return IIO_VAL_INT_PLUS_MICRO;
 728         }
 729         return -EINVAL;
 730 }
 731 
 732 static const struct iio_mount_matrix *
 733 ak8975_get_mount_matrix(const struct iio_dev *indio_dev,
 734                         const struct iio_chan_spec *chan)
 735 {
 736         struct ak8975_data *data = iio_priv(indio_dev);
 737 
 738         return &data->orientation;
 739 }
 740 
 741 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
 742         IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),
 743         { }
 744 };
 745 
 746 #define AK8975_CHANNEL(axis, index)                                     \
 747         {                                                               \
 748                 .type = IIO_MAGN,                                       \
 749                 .modified = 1,                                          \
 750                 .channel2 = IIO_MOD_##axis,                             \
 751                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |          \
 752                              BIT(IIO_CHAN_INFO_SCALE),                  \
 753                 .address = index,                                       \
 754                 .scan_index = index,                                    \
 755                 .scan_type = {                                          \
 756                         .sign = 's',                                    \
 757                         .realbits = 16,                                 \
 758                         .storagebits = 16,                              \
 759                         .endianness = IIO_CPU                           \
 760                 },                                                      \
 761                 .ext_info = ak8975_ext_info,                            \
 762         }
 763 
 764 static const struct iio_chan_spec ak8975_channels[] = {
 765         AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
 766         IIO_CHAN_SOFT_TIMESTAMP(3),
 767 };
 768 
 769 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
 770 
 771 static const struct iio_info ak8975_info = {
 772         .read_raw = &ak8975_read_raw,
 773 };
 774 
 775 #ifdef CONFIG_ACPI
 776 static const struct acpi_device_id ak_acpi_match[] = {
 777         {"AK8975", AK8975},
 778         {"AK8963", AK8963},
 779         {"INVN6500", AK8963},
 780         {"AK009911", AK09911},
 781         {"AK09911", AK09911},
 782         {"AKM9911", AK09911},
 783         {"AK09912", AK09912},
 784         { }
 785 };
 786 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
 787 #endif
 788 
 789 static const char *ak8975_match_acpi_device(struct device *dev,
 790                                             enum asahi_compass_chipset *chipset)
 791 {
 792         const struct acpi_device_id *id;
 793 
 794         id = acpi_match_device(dev->driver->acpi_match_table, dev);
 795         if (!id)
 796                 return NULL;
 797         *chipset = (int)id->driver_data;
 798 
 799         return dev_name(dev);
 800 }
 801 
 802 static void ak8975_fill_buffer(struct iio_dev *indio_dev)
 803 {
 804         struct ak8975_data *data = iio_priv(indio_dev);
 805         const struct i2c_client *client = data->client;
 806         const struct ak_def *def = data->def;
 807         int ret;
 808         s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */
 809         __le16 fval[3];
 810 
 811         mutex_lock(&data->lock);
 812 
 813         ret = ak8975_start_read_axis(data, client);
 814         if (ret)
 815                 goto unlock;
 816 
 817         /*
 818          * For each axis, read the flux value from the appropriate register
 819          * (the register is specified in the iio device attributes).
 820          */
 821         ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
 822                                                         def->data_regs[0],
 823                                                         3 * sizeof(fval[0]),
 824                                                         (u8 *)fval);
 825         if (ret < 0)
 826                 goto unlock;
 827 
 828         mutex_unlock(&data->lock);
 829 
 830         /* Clamp to valid range. */
 831         buff[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);
 832         buff[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);
 833         buff[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);
 834 
 835         iio_push_to_buffers_with_timestamp(indio_dev, buff,
 836                                            iio_get_time_ns(indio_dev));
 837         return;
 838 
 839 unlock:
 840         mutex_unlock(&data->lock);
 841         dev_err(&client->dev, "Error in reading axes block\n");
 842 }
 843 
 844 static irqreturn_t ak8975_handle_trigger(int irq, void *p)
 845 {
 846         const struct iio_poll_func *pf = p;
 847         struct iio_dev *indio_dev = pf->indio_dev;
 848 
 849         ak8975_fill_buffer(indio_dev);
 850         iio_trigger_notify_done(indio_dev->trig);
 851         return IRQ_HANDLED;
 852 }
 853 
 854 static int ak8975_probe(struct i2c_client *client,
 855                         const struct i2c_device_id *id)
 856 {
 857         struct ak8975_data *data;
 858         struct iio_dev *indio_dev;
 859         int eoc_gpio;
 860         int err;
 861         const char *name = NULL;
 862         enum asahi_compass_chipset chipset = AK_MAX_TYPE;
 863         const struct ak8975_platform_data *pdata =
 864                 dev_get_platdata(&client->dev);
 865 
 866         /* Grab and set up the supplied GPIO. */
 867         if (pdata)
 868                 eoc_gpio = pdata->eoc_gpio;
 869         else if (client->dev.of_node)
 870                 eoc_gpio = of_get_gpio(client->dev.of_node, 0);
 871         else
 872                 eoc_gpio = -1;
 873 
 874         if (eoc_gpio == -EPROBE_DEFER)
 875                 return -EPROBE_DEFER;
 876 
 877         /* We may not have a GPIO based IRQ to scan, that is fine, we will
 878            poll if so */
 879         if (gpio_is_valid(eoc_gpio)) {
 880                 err = devm_gpio_request_one(&client->dev, eoc_gpio,
 881                                                         GPIOF_IN, "ak_8975");
 882                 if (err < 0) {
 883                         dev_err(&client->dev,
 884                                 "failed to request GPIO %d, error %d\n",
 885                                                         eoc_gpio, err);
 886                         return err;
 887                 }
 888         }
 889 
 890         /* Register with IIO */
 891         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 892         if (indio_dev == NULL)
 893                 return -ENOMEM;
 894 
 895         data = iio_priv(indio_dev);
 896         i2c_set_clientdata(client, indio_dev);
 897 
 898         data->client = client;
 899         data->eoc_gpio = eoc_gpio;
 900         data->eoc_irq = 0;
 901 
 902         if (!pdata) {
 903                 err = iio_read_mount_matrix(&client->dev, "mount-matrix",
 904                                             &data->orientation);
 905                 if (err)
 906                         return err;
 907         } else
 908                 data->orientation = pdata->orientation;
 909 
 910         /* id will be NULL when enumerated via ACPI */
 911         if (id) {
 912                 chipset = (enum asahi_compass_chipset)(id->driver_data);
 913                 name = id->name;
 914         } else if (ACPI_HANDLE(&client->dev)) {
 915                 name = ak8975_match_acpi_device(&client->dev, &chipset);
 916                 if (!name)
 917                         return -ENODEV;
 918         } else
 919                 return -ENOSYS;
 920 
 921         if (chipset >= AK_MAX_TYPE) {
 922                 dev_err(&client->dev, "AKM device type unsupported: %d\n",
 923                         chipset);
 924                 return -ENODEV;
 925         }
 926 
 927         data->def = &ak_def_array[chipset];
 928 
 929         /* Fetch the regulators */
 930         data->vdd = devm_regulator_get(&client->dev, "vdd");
 931         if (IS_ERR(data->vdd))
 932                 return PTR_ERR(data->vdd);
 933         data->vid = devm_regulator_get(&client->dev, "vid");
 934         if (IS_ERR(data->vid))
 935                 return PTR_ERR(data->vid);
 936 
 937         err = ak8975_power_on(data);
 938         if (err)
 939                 return err;
 940 
 941         err = ak8975_who_i_am(client, data->def->type);
 942         if (err < 0) {
 943                 dev_err(&client->dev, "Unexpected device\n");
 944                 goto power_off;
 945         }
 946         dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
 947 
 948         /* Perform some basic start-of-day setup of the device. */
 949         err = ak8975_setup(client);
 950         if (err < 0) {
 951                 dev_err(&client->dev, "%s initialization fails\n", name);
 952                 goto power_off;
 953         }
 954 
 955         mutex_init(&data->lock);
 956         indio_dev->dev.parent = &client->dev;
 957         indio_dev->channels = ak8975_channels;
 958         indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
 959         indio_dev->info = &ak8975_info;
 960         indio_dev->available_scan_masks = ak8975_scan_masks;
 961         indio_dev->modes = INDIO_DIRECT_MODE;
 962         indio_dev->name = name;
 963 
 964         err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
 965                                          NULL);
 966         if (err) {
 967                 dev_err(&client->dev, "triggered buffer setup failed\n");
 968                 goto power_off;
 969         }
 970 
 971         err = iio_device_register(indio_dev);
 972         if (err) {
 973                 dev_err(&client->dev, "device register failed\n");
 974                 goto cleanup_buffer;
 975         }
 976 
 977         /* Enable runtime PM */
 978         pm_runtime_get_noresume(&client->dev);
 979         pm_runtime_set_active(&client->dev);
 980         pm_runtime_enable(&client->dev);
 981         /*
 982          * The device comes online in 500us, so add two orders of magnitude
 983          * of delay before autosuspending: 50 ms.
 984          */
 985         pm_runtime_set_autosuspend_delay(&client->dev, 50);
 986         pm_runtime_use_autosuspend(&client->dev);
 987         pm_runtime_put(&client->dev);
 988 
 989         return 0;
 990 
 991 cleanup_buffer:
 992         iio_triggered_buffer_cleanup(indio_dev);
 993 power_off:
 994         ak8975_power_off(data);
 995         return err;
 996 }
 997 
 998 static int ak8975_remove(struct i2c_client *client)
 999 {
1000         struct iio_dev *indio_dev = i2c_get_clientdata(client);
1001         struct ak8975_data *data = iio_priv(indio_dev);
1002 
1003         pm_runtime_get_sync(&client->dev);
1004         pm_runtime_put_noidle(&client->dev);
1005         pm_runtime_disable(&client->dev);
1006         iio_device_unregister(indio_dev);
1007         iio_triggered_buffer_cleanup(indio_dev);
1008         ak8975_set_mode(data, POWER_DOWN);
1009         ak8975_power_off(data);
1010 
1011         return 0;
1012 }
1013 
1014 #ifdef CONFIG_PM
1015 static int ak8975_runtime_suspend(struct device *dev)
1016 {
1017         struct i2c_client *client = to_i2c_client(dev);
1018         struct iio_dev *indio_dev = i2c_get_clientdata(client);
1019         struct ak8975_data *data = iio_priv(indio_dev);
1020         int ret;
1021 
1022         /* Set the device in power down if it wasn't already */
1023         ret = ak8975_set_mode(data, POWER_DOWN);
1024         if (ret < 0) {
1025                 dev_err(&client->dev, "Error in setting power-down mode\n");
1026                 return ret;
1027         }
1028         /* Next cut the regulators */
1029         ak8975_power_off(data);
1030 
1031         return 0;
1032 }
1033 
1034 static int ak8975_runtime_resume(struct device *dev)
1035 {
1036         struct i2c_client *client = to_i2c_client(dev);
1037         struct iio_dev *indio_dev = i2c_get_clientdata(client);
1038         struct ak8975_data *data = iio_priv(indio_dev);
1039         int ret;
1040 
1041         /* Take up the regulators */
1042         ak8975_power_on(data);
1043         /*
1044          * We come up in powered down mode, the reading routines will
1045          * put us in the mode to read values later.
1046          */
1047         ret = ak8975_set_mode(data, POWER_DOWN);
1048         if (ret < 0) {
1049                 dev_err(&client->dev, "Error in setting power-down mode\n");
1050                 return ret;
1051         }
1052 
1053         return 0;
1054 }
1055 #endif /* CONFIG_PM */
1056 
1057 static const struct dev_pm_ops ak8975_dev_pm_ops = {
1058         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1059                                 pm_runtime_force_resume)
1060         SET_RUNTIME_PM_OPS(ak8975_runtime_suspend,
1061                            ak8975_runtime_resume, NULL)
1062 };
1063 
1064 static const struct i2c_device_id ak8975_id[] = {
1065         {"ak8975", AK8975},
1066         {"ak8963", AK8963},
1067         {"AK8963", AK8963},
1068         {"ak09911", AK09911},
1069         {"ak09912", AK09912},
1070         {}
1071 };
1072 
1073 MODULE_DEVICE_TABLE(i2c, ak8975_id);
1074 
1075 static const struct of_device_id ak8975_of_match[] = {
1076         { .compatible = "asahi-kasei,ak8975", },
1077         { .compatible = "ak8975", },
1078         { .compatible = "asahi-kasei,ak8963", },
1079         { .compatible = "ak8963", },
1080         { .compatible = "asahi-kasei,ak09911", },
1081         { .compatible = "ak09911", },
1082         { .compatible = "asahi-kasei,ak09912", },
1083         { .compatible = "ak09912", },
1084         {}
1085 };
1086 MODULE_DEVICE_TABLE(of, ak8975_of_match);
1087 
1088 static struct i2c_driver ak8975_driver = {
1089         .driver = {
1090                 .name   = "ak8975",
1091                 .pm = &ak8975_dev_pm_ops,
1092                 .of_match_table = of_match_ptr(ak8975_of_match),
1093                 .acpi_match_table = ACPI_PTR(ak_acpi_match),
1094         },
1095         .probe          = ak8975_probe,
1096         .remove         = ak8975_remove,
1097         .id_table       = ak8975_id,
1098 };
1099 module_i2c_driver(ak8975_driver);
1100 
1101 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1102 MODULE_DESCRIPTION("AK8975 magnetometer driver");
1103 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/iio/magnetometer/ak8975.c

DEFINITIONS
