drivers/iio/adc/twl4030-madc.c

   1 /*
   2  *
   3  * TWL4030 MADC module driver-This driver monitors the real time
   4  * conversion of analog signals like battery temperature,
   5  * battery type, battery level etc.
   6  *
   7  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
   8  * J Keerthy <j-keerthy@ti.com>
   9  *
  10  * Based on twl4030-madc.c
  11  * Copyright (C) 2008 Nokia Corporation
  12  * Mikko Ylinen <mikko.k.ylinen@nokia.com>
  13  *
  14  * Amit Kucheria <amit.kucheria@canonical.com>
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License
  18  * version 2 as published by the Free Software Foundation.
  19  *
  20  * This program is distributed in the hope that it will be useful, but
  21  * WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23  * General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  28  * 02110-1301 USA
  29  *
  30  */
  31
  32 #include <linux/device.h>
  33 #include <linux/interrupt.h>
  34 #include <linux/kernel.h>
  35 #include <linux/delay.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/slab.h>
  38 #include <linux/i2c/twl.h>
  39 #include <linux/i2c/twl4030-madc.h>
  40 #include <linux/module.h>
  41 #include <linux/stddef.h>
  42 #include <linux/mutex.h>
  43 #include <linux/bitops.h>
  44 #include <linux/jiffies.h>
  45 #include <linux/types.h>
  46 #include <linux/gfp.h>
  47 #include <linux/err.h>
  48
  49 #include <linux/iio/iio.h>
  50
  51 /**
  52  * struct twl4030_madc_data - a container for madc info
  53  * @dev:                Pointer to device structure for madc
  54  * @lock:               Mutex protecting this data structure
  55  * @requests:           Array of request struct corresponding to SW1, SW2 and RT
  56  * @use_second_irq:     IRQ selection (main or co-processor)
  57  * @imr:                Interrupt mask register of MADC
  58  * @isr:                Interrupt status register of MADC
  59  */
  60 struct twl4030_madc_data {
  61         struct device *dev;
  62         struct mutex lock;      /* mutex protecting this data structure */
  63         struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
  64         bool use_second_irq;
  65         u8 imr;
  66         u8 isr;
  67 };
  68
  69 static int twl4030_madc_read(struct iio_dev *iio_dev,
  70                              const struct iio_chan_spec *chan,
  71                              int *val, int *val2, long mask)
  72 {
  73         struct twl4030_madc_data *madc = iio_priv(iio_dev);
  74         struct twl4030_madc_request req;
  75         int ret;
  76
  77         req.method = madc->use_second_irq ? TWL4030_MADC_SW2 : TWL4030_MADC_SW1;
  78
  79         req.channels = BIT(chan->channel);
  80         req.active = false;
  81         req.func_cb = NULL;
  82         req.type = TWL4030_MADC_WAIT;
  83         req.raw = !(mask == IIO_CHAN_INFO_PROCESSED);
  84         req.do_avg = (mask == IIO_CHAN_INFO_AVERAGE_RAW);
  85
  86         ret = twl4030_madc_conversion(&req);
  87         if (ret < 0)
  88                 return ret;
  89
  90         *val = req.rbuf[chan->channel];
  91
  92         return IIO_VAL_INT;
  93 }
  94
  95 static const struct iio_info twl4030_madc_iio_info = {
  96         .read_raw = &twl4030_madc_read,
  97         .driver_module = THIS_MODULE,
  98 };
  99
 100 #define TWL4030_ADC_CHANNEL(_channel, _type, _name) {   \
 101         .type = _type,                                  \
 102         .channel = _channel,                            \
 103         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
 104                               BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
 105                               BIT(IIO_CHAN_INFO_PROCESSED), \
 106         .datasheet_name = _name,                        \
 107         .indexed = 1,                                   \
 108 }
 109
 110 static const struct iio_chan_spec twl4030_madc_iio_channels[] = {
 111         TWL4030_ADC_CHANNEL(0, IIO_VOLTAGE, "ADCIN0"),
 112         TWL4030_ADC_CHANNEL(1, IIO_TEMP, "ADCIN1"),
 113         TWL4030_ADC_CHANNEL(2, IIO_VOLTAGE, "ADCIN2"),
 114         TWL4030_ADC_CHANNEL(3, IIO_VOLTAGE, "ADCIN3"),
 115         TWL4030_ADC_CHANNEL(4, IIO_VOLTAGE, "ADCIN4"),
 116         TWL4030_ADC_CHANNEL(5, IIO_VOLTAGE, "ADCIN5"),
 117         TWL4030_ADC_CHANNEL(6, IIO_VOLTAGE, "ADCIN6"),
 118         TWL4030_ADC_CHANNEL(7, IIO_VOLTAGE, "ADCIN7"),
 119         TWL4030_ADC_CHANNEL(8, IIO_VOLTAGE, "ADCIN8"),
 120         TWL4030_ADC_CHANNEL(9, IIO_VOLTAGE, "ADCIN9"),
 121         TWL4030_ADC_CHANNEL(10, IIO_CURRENT, "ADCIN10"),
 122         TWL4030_ADC_CHANNEL(11, IIO_VOLTAGE, "ADCIN11"),
 123         TWL4030_ADC_CHANNEL(12, IIO_VOLTAGE, "ADCIN12"),
 124         TWL4030_ADC_CHANNEL(13, IIO_VOLTAGE, "ADCIN13"),
 125         TWL4030_ADC_CHANNEL(14, IIO_VOLTAGE, "ADCIN14"),
 126         TWL4030_ADC_CHANNEL(15, IIO_VOLTAGE, "ADCIN15"),
 127 };
 128
 129 static struct twl4030_madc_data *twl4030_madc;
 130
 131 struct twl4030_prescale_divider_ratios {
 132         s16 numerator;
 133         s16 denominator;
 134 };
 135
 136 static const struct twl4030_prescale_divider_ratios
 137 twl4030_divider_ratios[16] = {
 138         {1, 1},         /* CHANNEL 0 No Prescaler */
 139         {1, 1},         /* CHANNEL 1 No Prescaler */
 140         {6, 10},        /* CHANNEL 2 */
 141         {6, 10},        /* CHANNEL 3 */
 142         {6, 10},        /* CHANNEL 4 */
 143         {6, 10},        /* CHANNEL 5 */
 144         {6, 10},        /* CHANNEL 6 */
 145         {6, 10},        /* CHANNEL 7 */
 146         {3, 14},        /* CHANNEL 8 */
 147         {1, 3},         /* CHANNEL 9 */
 148         {1, 1},         /* CHANNEL 10 No Prescaler */
 149         {15, 100},      /* CHANNEL 11 */
 150         {1, 4},         /* CHANNEL 12 */
 151         {1, 1},         /* CHANNEL 13 Reserved channels */
 152         {1, 1},         /* CHANNEL 14 Reseved channels */
 153         {5, 11},        /* CHANNEL 15 */
 154 };
 155
 156
 157 /* Conversion table from -3 to 55 degrees Celcius */
 158 static int twl4030_therm_tbl[] = {
 159         30800,  29500,  28300,  27100,
 160         26000,  24900,  23900,  22900,  22000,  21100,  20300,  19400,  18700,
 161         17900,  17200,  16500,  15900,  15300,  14700,  14100,  13600,  13100,
 162         12600,  12100,  11600,  11200,  10800,  10400,  10000,  9630,   9280,
 163         8950,   8620,   8310,   8020,   7730,   7460,   7200,   6950,   6710,
 164         6470,   6250,   6040,   5830,   5640,   5450,   5260,   5090,   4920,
 165         4760,   4600,   4450,   4310,   4170,   4040,   3910,   3790,   3670,
 166         3550
 167 };
 168
 169 /*
 170  * Structure containing the registers
 171  * of different conversion methods supported by MADC.
 172  * Hardware or RT real time conversion request initiated by external host
 173  * processor for RT Signal conversions.
 174  * External host processors can also request for non RT conversions
 175  * SW1 and SW2 software conversions also called asynchronous or GPC request.
 176  */
 177 static
 178 const struct twl4030_madc_conversion_method twl4030_conversion_methods[] = {
 179         [TWL4030_MADC_RT] = {
 180                              .sel = TWL4030_MADC_RTSELECT_LSB,
 181                              .avg = TWL4030_MADC_RTAVERAGE_LSB,
 182                              .rbase = TWL4030_MADC_RTCH0_LSB,
 183                              },
 184         [TWL4030_MADC_SW1] = {
 185                               .sel = TWL4030_MADC_SW1SELECT_LSB,
 186                               .avg = TWL4030_MADC_SW1AVERAGE_LSB,
 187                               .rbase = TWL4030_MADC_GPCH0_LSB,
 188                               .ctrl = TWL4030_MADC_CTRL_SW1,
 189                               },
 190         [TWL4030_MADC_SW2] = {
 191                               .sel = TWL4030_MADC_SW2SELECT_LSB,
 192                               .avg = TWL4030_MADC_SW2AVERAGE_LSB,
 193                               .rbase = TWL4030_MADC_GPCH0_LSB,
 194                               .ctrl = TWL4030_MADC_CTRL_SW2,
 195                               },
 196 };
 197
 198 /**
 199  * twl4030_madc_channel_raw_read() - Function to read a particular channel value
 200  * @madc:       pointer to struct twl4030_madc_data
 201  * @reg:        lsb of ADC Channel
 202  *
 203  * Return: 0 on success, an error code otherwise.
 204  */
 205 static int twl4030_madc_channel_raw_read(struct twl4030_madc_data *madc, u8 reg)
 206 {
 207         u16 val;
 208         int ret;
 209         /*
 210          * For each ADC channel, we have MSB and LSB register pair. MSB address
 211          * is always LSB address+1. reg parameter is the address of LSB register
 212          */
 213         ret = twl_i2c_read_u16(TWL4030_MODULE_MADC, &val, reg);
 214         if (ret) {
 215                 dev_err(madc->dev, "unable to read register 0x%X\n", reg);
 216                 return ret;
 217         }
 218
 219         return (int)(val >> 6);
 220 }
 221
 222 /*
 223  * Return battery temperature in degrees Celsius
 224  * Or < 0 on failure.
 225  */
 226 static int twl4030battery_temperature(int raw_volt)
 227 {
 228         u8 val;
 229         int temp, curr, volt, res, ret;
 230
 231         volt = (raw_volt * TEMP_STEP_SIZE) / TEMP_PSR_R;
 232         /* Getting and calculating the supply current in micro amperes */
 233         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val,
 234                 REG_BCICTL2);
 235         if (ret < 0)
 236                 return ret;
 237
 238         curr = ((val & TWL4030_BCI_ITHSENS) + 1) * 10;
 239         /* Getting and calculating the thermistor resistance in ohms */
 240         res = volt * 1000 / curr;
 241         /* calculating temperature */
 242         for (temp = 58; temp >= 0; temp--) {
 243                 int actual = twl4030_therm_tbl[temp];
 244                 if ((actual - res) >= 0)
 245                         break;
 246         }
 247
 248         return temp + 1;
 249 }
 250
 251 static int twl4030battery_current(int raw_volt)
 252 {
 253         int ret;
 254         u8 val;
 255
 256         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val,
 257                 TWL4030_BCI_BCICTL1);
 258         if (ret)
 259                 return ret;
 260         if (val & TWL4030_BCI_CGAIN) /* slope of 0.44 mV/mA */
 261                 return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R1;
 262         else /* slope of 0.88 mV/mA */
 263                 return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R2;
 264 }
 265
 266 /*
 267  * Function to read channel values
 268  * @madc - pointer to twl4030_madc_data struct
 269  * @reg_base - Base address of the first channel
 270  * @Channels - 16 bit bitmap. If the bit is set, channel's value is read
 271  * @buf - The channel values are stored here. if read fails error
 272  * @raw - Return raw values without conversion
 273  * value is stored
 274  * Returns the number of successfully read channels.
 275  */
 276 static int twl4030_madc_read_channels(struct twl4030_madc_data *madc,
 277                                       u8 reg_base, unsigned
 278                                       long channels, int *buf,
 279                                       bool raw)
 280 {
 281         int count = 0;
 282         int i;
 283         u8 reg;
 284
 285         for_each_set_bit(i, &channels, TWL4030_MADC_MAX_CHANNELS) {
 286                 reg = reg_base + (2 * i);
 287                 buf[i] = twl4030_madc_channel_raw_read(madc, reg);
 288                 if (buf[i] < 0) {
 289                         dev_err(madc->dev, "Unable to read register 0x%X\n",
 290                                 reg);
 291                         return buf[i];
 292                 }
 293                 if (raw) {
 294                         count++;
 295                         continue;
 296                 }
 297                 switch (i) {
 298                 case 10:
 299                         buf[i] = twl4030battery_current(buf[i]);
 300                         if (buf[i] < 0) {
 301                                 dev_err(madc->dev, "err reading current\n");
 302                                 return buf[i];
 303                         } else {
 304                                 count++;
 305                                 buf[i] = buf[i] - 750;
 306                         }
 307                         break;
 308                 case 1:
 309                         buf[i] = twl4030battery_temperature(buf[i]);
 310                         if (buf[i] < 0) {
 311                                 dev_err(madc->dev, "err reading temperature\n");
 312                                 return buf[i];
 313                         } else {
 314                                 buf[i] -= 3;
 315                                 count++;
 316                         }
 317                         break;
 318                 default:
 319                         count++;
 320                         /* Analog Input (V) = conv_result * step_size / R
 321                          * conv_result = decimal value of 10-bit conversion
 322                          *               result
 323                          * step size = 1.5 / (2 ^ 10 -1)
 324                          * R = Prescaler ratio for input channels.
 325                          * Result given in mV hence multiplied by 1000.
 326                          */
 327                         buf[i] = (buf[i] * 3 * 1000 *
 328                                  twl4030_divider_ratios[i].denominator)
 329                                 / (2 * 1023 *
 330                                 twl4030_divider_ratios[i].numerator);
 331                 }
 332         }
 333
 334         return count;
 335 }
 336
 337 /*
 338  * Enables irq.
 339  * @madc - pointer to twl4030_madc_data struct
 340  * @id - irq number to be enabled
 341  * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2
 342  * corresponding to RT, SW1, SW2 conversion requests.
 343  * If the i2c read fails it returns an error else returns 0.
 344  */
 345 static int twl4030_madc_enable_irq(struct twl4030_madc_data *madc, u8 id)
 346 {
 347         u8 val;
 348         int ret;
 349
 350         ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr);
 351         if (ret) {
 352                 dev_err(madc->dev, "unable to read imr register 0x%X\n",
 353                         madc->imr);
 354                 return ret;
 355         }
 356
 357         val &= ~(1 << id);
 358         ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr);
 359         if (ret) {
 360                 dev_err(madc->dev,
 361                         "unable to write imr register 0x%X\n", madc->imr);
 362                 return ret;
 363         }
 364
 365         return 0;
 366 }
 367
 368 /*
 369  * Disables irq.
 370  * @madc - pointer to twl4030_madc_data struct
 371  * @id - irq number to be disabled
 372  * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2
 373  * corresponding to RT, SW1, SW2 conversion requests.
 374  * Returns error if i2c read/write fails.
 375  */
 376 static int twl4030_madc_disable_irq(struct twl4030_madc_data *madc, u8 id)
 377 {
 378         u8 val;
 379         int ret;
 380
 381         ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr);
 382         if (ret) {
 383                 dev_err(madc->dev, "unable to read imr register 0x%X\n",
 384                         madc->imr);
 385                 return ret;
 386         }
 387         val |= (1 << id);
 388         ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr);
 389         if (ret) {
 390                 dev_err(madc->dev,
 391                         "unable to write imr register 0x%X\n", madc->imr);
 392                 return ret;
 393         }
 394
 395         return 0;
 396 }
 397
 398 static irqreturn_t twl4030_madc_threaded_irq_handler(int irq, void *_madc)
 399 {
 400         struct twl4030_madc_data *madc = _madc;
 401         const struct twl4030_madc_conversion_method *method;
 402         u8 isr_val, imr_val;
 403         int i, len, ret;
 404         struct twl4030_madc_request *r;
 405
 406         mutex_lock(&madc->lock);
 407         ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &isr_val, madc->isr);
 408         if (ret) {
 409                 dev_err(madc->dev, "unable to read isr register 0x%X\n",
 410                         madc->isr);
 411                 goto err_i2c;
 412         }
 413         ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &imr_val, madc->imr);
 414         if (ret) {
 415                 dev_err(madc->dev, "unable to read imr register 0x%X\n",
 416                         madc->imr);
 417                 goto err_i2c;
 418         }
 419         isr_val &= ~imr_val;
 420         for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
 421                 if (!(isr_val & (1 << i)))
 422                         continue;
 423                 ret = twl4030_madc_disable_irq(madc, i);
 424                 if (ret < 0)
 425                         dev_dbg(madc->dev, "Disable interrupt failed %d\n", i);
 426                 madc->requests[i].result_pending = 1;
 427         }
 428         for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
 429                 r = &madc->requests[i];
 430                 /* No pending results for this method, move to next one */
 431                 if (!r->result_pending)
 432                         continue;
 433                 method = &twl4030_conversion_methods[r->method];
 434                 /* Read results */
 435                 len = twl4030_madc_read_channels(madc, method->rbase,
 436                                                  r->channels, r->rbuf, r->raw);
 437                 /* Return results to caller */
 438                 if (r->func_cb != NULL) {
 439                         r->func_cb(len, r->channels, r->rbuf);
 440                         r->func_cb = NULL;
 441                 }
 442                 /* Free request */
 443                 r->result_pending = 0;
 444                 r->active = 0;
 445         }
 446         mutex_unlock(&madc->lock);
 447
 448         return IRQ_HANDLED;
 449
 450 err_i2c:
 451         /*
 452          * In case of error check whichever request is active
 453          * and service the same.
 454          */
 455         for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
 456                 r = &madc->requests[i];
 457                 if (r->active == 0)
 458                         continue;
 459                 method = &twl4030_conversion_methods[r->method];
 460                 /* Read results */
 461                 len = twl4030_madc_read_channels(madc, method->rbase,
 462                                                  r->channels, r->rbuf, r->raw);
 463                 /* Return results to caller */
 464                 if (r->func_cb != NULL) {
 465                         r->func_cb(len, r->channels, r->rbuf);
 466                         r->func_cb = NULL;
 467                 }
 468                 /* Free request */
 469                 r->result_pending = 0;
 470                 r->active = 0;
 471         }
 472         mutex_unlock(&madc->lock);
 473
 474         return IRQ_HANDLED;
 475 }
 476
 477 static int twl4030_madc_set_irq(struct twl4030_madc_data *madc,
 478                                 struct twl4030_madc_request *req)
 479 {
 480         struct twl4030_madc_request *p;
 481         int ret;
 482
 483         p = &madc->requests[req->method];
 484         memcpy(p, req, sizeof(*req));
 485         ret = twl4030_madc_enable_irq(madc, req->method);
 486         if (ret < 0) {
 487                 dev_err(madc->dev, "enable irq failed!!\n");
 488                 return ret;
 489         }
 490
 491         return 0;
 492 }
 493
 494 /*
 495  * Function which enables the madc conversion
 496  * by writing to the control register.
 497  * @madc - pointer to twl4030_madc_data struct
 498  * @conv_method - can be TWL4030_MADC_RT, TWL4030_MADC_SW2, TWL4030_MADC_SW1
 499  * corresponding to RT SW1 or SW2 conversion methods.
 500  * Returns 0 if succeeds else a negative error value
 501  */
 502 static int twl4030_madc_start_conversion(struct twl4030_madc_data *madc,
 503                                          int conv_method)
 504 {
 505         const struct twl4030_madc_conversion_method *method;
 506         int ret = 0;
 507
 508         if (conv_method != TWL4030_MADC_SW1 && conv_method != TWL4030_MADC_SW2)
 509                 return -ENOTSUPP;
 510
 511         method = &twl4030_conversion_methods[conv_method];
 512         ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, TWL4030_MADC_SW_START,
 513                                method->ctrl);
 514         if (ret) {
 515                 dev_err(madc->dev, "unable to write ctrl register 0x%X\n",
 516                         method->ctrl);
 517                 return ret;
 518         }
 519
 520         return 0;
 521 }
 522
 523 /*
 524  * Function that waits for conversion to be ready
 525  * @madc - pointer to twl4030_madc_data struct
 526  * @timeout_ms - timeout value in milliseconds
 527  * @status_reg - ctrl register
 528  * returns 0 if succeeds else a negative error value
 529  */
 530 static int twl4030_madc_wait_conversion_ready(struct twl4030_madc_data *madc,
 531                                               unsigned int timeout_ms,
 532                                               u8 status_reg)
 533 {
 534         unsigned long timeout;
 535         int ret;
 536
 537         timeout = jiffies + msecs_to_jiffies(timeout_ms);
 538         do {
 539                 u8 reg;
 540
 541                 ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &reg, status_reg);
 542                 if (ret) {
 543                         dev_err(madc->dev,
 544                                 "unable to read status register 0x%X\n",
 545                                 status_reg);
 546                         return ret;
 547                 }
 548                 if (!(reg & TWL4030_MADC_BUSY) && (reg & TWL4030_MADC_EOC_SW))
 549                         return 0;
 550                 usleep_range(500, 2000);
 551         } while (!time_after(jiffies, timeout));
 552         dev_err(madc->dev, "conversion timeout!\n");
 553
 554         return -EAGAIN;
 555 }
 556
 557 /*
 558  * An exported function which can be called from other kernel drivers.
 559  * @req twl4030_madc_request structure
 560  * req->rbuf will be filled with read values of channels based on the
 561  * channel index. If a particular channel reading fails there will
 562  * be a negative error value in the corresponding array element.
 563  * returns 0 if succeeds else error value
 564  */
 565 int twl4030_madc_conversion(struct twl4030_madc_request *req)
 566 {
 567         const struct twl4030_madc_conversion_method *method;
 568         int ret;
 569
 570         if (!req || !twl4030_madc)
 571                 return -EINVAL;
 572
 573         mutex_lock(&twl4030_madc->lock);
 574         if (req->method < TWL4030_MADC_RT || req->method > TWL4030_MADC_SW2) {
 575                 ret = -EINVAL;
 576                 goto out;
 577         }
 578         /* Do we have a conversion request ongoing */
 579         if (twl4030_madc->requests[req->method].active) {
 580                 ret = -EBUSY;
 581                 goto out;
 582         }
 583         method = &twl4030_conversion_methods[req->method];
 584         /* Select channels to be converted */
 585         ret = twl_i2c_write_u16(TWL4030_MODULE_MADC, req->channels, method->sel);
 586         if (ret) {
 587                 dev_err(twl4030_madc->dev,
 588                         "unable to write sel register 0x%X\n", method->sel);
 589                 goto out;
 590         }
 591         /* Select averaging for all channels if do_avg is set */
 592         if (req->do_avg) {
 593                 ret = twl_i2c_write_u16(TWL4030_MODULE_MADC, req->channels,
 594                                        method->avg);
 595                 if (ret) {
 596                         dev_err(twl4030_madc->dev,
 597                                 "unable to write avg register 0x%X\n",
 598                                 method->avg);
 599                         goto out;
 600                 }
 601         }
 602         if (req->type == TWL4030_MADC_IRQ_ONESHOT && req->func_cb != NULL) {
 603                 ret = twl4030_madc_set_irq(twl4030_madc, req);
 604                 if (ret < 0)
 605                         goto out;
 606                 ret = twl4030_madc_start_conversion(twl4030_madc, req->method);
 607                 if (ret < 0)
 608                         goto out;
 609                 twl4030_madc->requests[req->method].active = 1;
 610                 ret = 0;
 611                 goto out;
 612         }
 613         /* With RT method we should not be here anymore */
 614         if (req->method == TWL4030_MADC_RT) {
 615                 ret = -EINVAL;
 616                 goto out;
 617         }
 618         ret = twl4030_madc_start_conversion(twl4030_madc, req->method);
 619         if (ret < 0)
 620                 goto out;
 621         twl4030_madc->requests[req->method].active = 1;
 622         /* Wait until conversion is ready (ctrl register returns EOC) */
 623         ret = twl4030_madc_wait_conversion_ready(twl4030_madc, 5, method->ctrl);
 624         if (ret) {
 625                 twl4030_madc->requests[req->method].active = 0;
 626                 goto out;
 627         }
 628         ret = twl4030_madc_read_channels(twl4030_madc, method->rbase,
 629                                          req->channels, req->rbuf, req->raw);
 630         twl4030_madc->requests[req->method].active = 0;
 631
 632 out:
 633         mutex_unlock(&twl4030_madc->lock);
 634
 635         return ret;
 636 }
 637 EXPORT_SYMBOL_GPL(twl4030_madc_conversion);
 638
 639 int twl4030_get_madc_conversion(int channel_no)
 640 {
 641         struct twl4030_madc_request req;
 642         int temp = 0;
 643         int ret;
 644
 645         req.channels = (1 << channel_no);
 646         req.method = TWL4030_MADC_SW2;
 647         req.active = 0;
 648         req.raw = 0;
 649         req.func_cb = NULL;
 650         ret = twl4030_madc_conversion(&req);
 651         if (ret < 0)
 652                 return ret;
 653         if (req.rbuf[channel_no] > 0)
 654                 temp = req.rbuf[channel_no];
 655
 656         return temp;
 657 }
 658 EXPORT_SYMBOL_GPL(twl4030_get_madc_conversion);
 659
 660 /**
 661  * twl4030_madc_set_current_generator() - setup bias current
 662  *
 663  * @madc:       pointer to twl4030_madc_data struct
 664  * @chan:       can be one of the two values:
 665  *              0 - Enables bias current for main battery type reading
 666  *              1 - Enables bias current for main battery temperature sensing
 667  * @on:         enable or disable chan.
 668  *
 669  * Function to enable or disable bias current for
 670  * main battery type reading or temperature sensing
 671  */
 672 static int twl4030_madc_set_current_generator(struct twl4030_madc_data *madc,
 673                                               int chan, int on)
 674 {
 675         int ret;
 676         int regmask;
 677         u8 regval;
 678
 679         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
 680                               &regval, TWL4030_BCI_BCICTL1);
 681         if (ret) {
 682                 dev_err(madc->dev, "unable to read BCICTL1 reg 0x%X",
 683                         TWL4030_BCI_BCICTL1);
 684                 return ret;
 685         }
 686
 687         regmask = chan ? TWL4030_BCI_ITHEN : TWL4030_BCI_TYPEN;
 688         if (on)
 689                 regval |= regmask;
 690         else
 691                 regval &= ~regmask;
 692
 693         ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
 694                                regval, TWL4030_BCI_BCICTL1);
 695         if (ret) {
 696                 dev_err(madc->dev, "unable to write BCICTL1 reg 0x%X\n",
 697                         TWL4030_BCI_BCICTL1);
 698                 return ret;
 699         }
 700
 701         return 0;
 702 }
 703
 704 /*
 705  * Function that sets MADC software power on bit to enable MADC
 706  * @madc - pointer to twl4030_madc_data struct
 707  * @on - Enable or disable MADC software power on bit.
 708  * returns error if i2c read/write fails else 0
 709  */
 710 static int twl4030_madc_set_power(struct twl4030_madc_data *madc, int on)
 711 {
 712         u8 regval;
 713         int ret;
 714
 715         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
 716                               &regval, TWL4030_MADC_CTRL1);
 717         if (ret) {
 718                 dev_err(madc->dev, "unable to read madc ctrl1 reg 0x%X\n",
 719                         TWL4030_MADC_CTRL1);
 720                 return ret;
 721         }
 722         if (on)
 723                 regval |= TWL4030_MADC_MADCON;
 724         else
 725                 regval &= ~TWL4030_MADC_MADCON;
 726         ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, regval, TWL4030_MADC_CTRL1);
 727         if (ret) {
 728                 dev_err(madc->dev, "unable to write madc ctrl1 reg 0x%X\n",
 729                         TWL4030_MADC_CTRL1);
 730                 return ret;
 731         }
 732
 733         return 0;
 734 }
 735
 736 /*
 737  * Initialize MADC and request for threaded irq
 738  */
 739 static int twl4030_madc_probe(struct platform_device *pdev)
 740 {
 741         struct twl4030_madc_data *madc;
 742         struct twl4030_madc_platform_data *pdata = dev_get_platdata(&pdev->dev);
 743         struct device_node *np = pdev->dev.of_node;
 744         int irq, ret;
 745         u8 regval;
 746         struct iio_dev *iio_dev = NULL;
 747
 748         if (!pdata && !np) {
 749                 dev_err(&pdev->dev, "neither platform data nor Device Tree node available\n");
 750                 return -EINVAL;
 751         }
 752
 753         iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*madc));
 754         if (!iio_dev) {
 755                 dev_err(&pdev->dev, "failed allocating iio device\n");
 756                 return -ENOMEM;
 757         }
 758
 759         madc = iio_priv(iio_dev);
 760         madc->dev = &pdev->dev;
 761
 762         iio_dev->name = dev_name(&pdev->dev);
 763         iio_dev->dev.parent = &pdev->dev;
 764         iio_dev->dev.of_node = pdev->dev.of_node;
 765         iio_dev->info = &twl4030_madc_iio_info;
 766         iio_dev->modes = INDIO_DIRECT_MODE;
 767         iio_dev->channels = twl4030_madc_iio_channels;
 768         iio_dev->num_channels = ARRAY_SIZE(twl4030_madc_iio_channels);
 769
 770         /*
 771          * Phoenix provides 2 interrupt lines. The first one is connected to
 772          * the OMAP. The other one can be connected to the other processor such
 773          * as modem. Hence two separate ISR and IMR registers.
 774          */
 775         if (pdata)
 776                 madc->use_second_irq = (pdata->irq_line != 1);
 777         else
 778                 madc->use_second_irq = of_property_read_bool(np,
 779                                        "ti,system-uses-second-madc-irq");
 780
 781         madc->imr = madc->use_second_irq ? TWL4030_MADC_IMR2 :
 782                                            TWL4030_MADC_IMR1;
 783         madc->isr = madc->use_second_irq ? TWL4030_MADC_ISR2 :
 784                                            TWL4030_MADC_ISR1;
 785
 786         ret = twl4030_madc_set_power(madc, 1);
 787         if (ret < 0)
 788                 return ret;
 789         ret = twl4030_madc_set_current_generator(madc, 0, 1);
 790         if (ret < 0)
 791                 goto err_current_generator;
 792
 793         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
 794                               &regval, TWL4030_BCI_BCICTL1);
 795         if (ret) {
 796                 dev_err(&pdev->dev, "unable to read reg BCI CTL1 0x%X\n",
 797                         TWL4030_BCI_BCICTL1);
 798                 goto err_i2c;
 799         }
 800         regval |= TWL4030_BCI_MESBAT;
 801         ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
 802                                regval, TWL4030_BCI_BCICTL1);
 803         if (ret) {
 804                 dev_err(&pdev->dev, "unable to write reg BCI Ctl1 0x%X\n",
 805                         TWL4030_BCI_BCICTL1);
 806                 goto err_i2c;
 807         }
 808
 809         /* Check that MADC clock is on */
 810         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &regval, TWL4030_REG_GPBR1);
 811         if (ret) {
 812                 dev_err(&pdev->dev, "unable to read reg GPBR1 0x%X\n",
 813                                 TWL4030_REG_GPBR1);
 814                 goto err_i2c;
 815         }
 816
 817         /* If MADC clk is not on, turn it on */
 818         if (!(regval & TWL4030_GPBR1_MADC_HFCLK_EN)) {
 819                 dev_info(&pdev->dev, "clk disabled, enabling\n");
 820                 regval |= TWL4030_GPBR1_MADC_HFCLK_EN;
 821                 ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, regval,
 822                                        TWL4030_REG_GPBR1);
 823                 if (ret) {
 824                         dev_err(&pdev->dev, "unable to write reg GPBR1 0x%X\n",
 825                                         TWL4030_REG_GPBR1);
 826                         goto err_i2c;
 827                 }
 828         }
 829
 830         platform_set_drvdata(pdev, iio_dev);
 831         mutex_init(&madc->lock);
 832
 833         irq = platform_get_irq(pdev, 0);
 834         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 835                                    twl4030_madc_threaded_irq_handler,
 836                                    IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 837                                    "twl4030_madc", madc);
 838         if (ret) {
 839                 dev_err(&pdev->dev, "could not request irq\n");
 840                 goto err_i2c;
 841         }
 842         twl4030_madc = madc;
 843
 844         ret = iio_device_register(iio_dev);
 845         if (ret) {
 846                 dev_err(&pdev->dev, "could not register iio device\n");
 847                 goto err_i2c;
 848         }
 849
 850         return 0;
 851
 852 err_i2c:
 853         twl4030_madc_set_current_generator(madc, 0, 0);
 854 err_current_generator:
 855         twl4030_madc_set_power(madc, 0);
 856         return ret;
 857 }
 858
 859 static int twl4030_madc_remove(struct platform_device *pdev)
 860 {
 861         struct iio_dev *iio_dev = platform_get_drvdata(pdev);
 862         struct twl4030_madc_data *madc = iio_priv(iio_dev);
 863
 864         iio_device_unregister(iio_dev);
 865
 866         twl4030_madc_set_current_generator(madc, 0, 0);
 867         twl4030_madc_set_power(madc, 0);
 868
 869         return 0;
 870 }
 871
 872 #ifdef CONFIG_OF
 873 static const struct of_device_id twl_madc_of_match[] = {
 874         { .compatible = "ti,twl4030-madc", },
 875         { },
 876 };
 877 MODULE_DEVICE_TABLE(of, twl_madc_of_match);
 878 #endif
 879
 880 static struct platform_driver twl4030_madc_driver = {
 881         .probe = twl4030_madc_probe,
 882         .remove = twl4030_madc_remove,
 883         .driver = {
 884                    .name = "twl4030_madc",
 885                    .of_match_table = of_match_ptr(twl_madc_of_match),
 886         },
 887 };
 888
 889 module_platform_driver(twl4030_madc_driver);
 890
 891 MODULE_DESCRIPTION("TWL4030 ADC driver");
 892 MODULE_LICENSE("GPL");
 893 MODULE_AUTHOR("J Keerthy");
 894 MODULE_ALIAS("platform:twl4030_madc");