drivers/iio/adc/twl4030-madc.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
twl4030_madc_read
twl4030_madc_channel_raw_read
twl4030battery_temperature
twl4030battery_current
twl4030_madc_read_channels
twl4030_madc_disable_irq
twl4030_madc_threaded_irq_handler
twl4030_madc_start_conversion
twl4030_madc_wait_conversion_ready
twl4030_madc_conversion
twl4030_madc_set_current_generator
twl4030_madc_set_power
twl4030_madc_probe
twl4030_madc_remove
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *
   4  * TWL4030 MADC module driver-This driver monitors the real time
   5  * conversion of analog signals like battery temperature,
   6  * battery type, battery level etc.
   7  *
   8  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
   9  * J Keerthy <j-keerthy@ti.com>
  10  *
  11  * Based on twl4030-madc.c
  12  * Copyright (C) 2008 Nokia Corporation
  13  * Mikko Ylinen <mikko.k.ylinen@nokia.com>
  14  *
  15  * Amit Kucheria <amit.kucheria@canonical.com>
  16  */
  17 
  18 #include <linux/device.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/kernel.h>
  21 #include <linux/delay.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/slab.h>
  24 #include <linux/mfd/twl.h>
  25 #include <linux/module.h>
  26 #include <linux/stddef.h>
  27 #include <linux/mutex.h>
  28 #include <linux/bitops.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/types.h>
  31 #include <linux/gfp.h>
  32 #include <linux/err.h>
  33 #include <linux/regulator/consumer.h>
  34 
  35 #include <linux/iio/iio.h>
  36 
  37 #define TWL4030_MADC_MAX_CHANNELS 16
  38 
  39 #define TWL4030_MADC_CTRL1              0x00
  40 #define TWL4030_MADC_CTRL2              0x01
  41 
  42 #define TWL4030_MADC_RTSELECT_LSB       0x02
  43 #define TWL4030_MADC_SW1SELECT_LSB      0x06
  44 #define TWL4030_MADC_SW2SELECT_LSB      0x0A
  45 
  46 #define TWL4030_MADC_RTAVERAGE_LSB      0x04
  47 #define TWL4030_MADC_SW1AVERAGE_LSB     0x08
  48 #define TWL4030_MADC_SW2AVERAGE_LSB     0x0C
  49 
  50 #define TWL4030_MADC_CTRL_SW1           0x12
  51 #define TWL4030_MADC_CTRL_SW2           0x13
  52 
  53 #define TWL4030_MADC_RTCH0_LSB          0x17
  54 #define TWL4030_MADC_GPCH0_LSB          0x37
  55 
  56 #define TWL4030_MADC_MADCON     (1 << 0)        /* MADC power on */
  57 #define TWL4030_MADC_BUSY       (1 << 0)        /* MADC busy */
  58 /* MADC conversion completion */
  59 #define TWL4030_MADC_EOC_SW     (1 << 1)
  60 /* MADC SWx start conversion */
  61 #define TWL4030_MADC_SW_START   (1 << 5)
  62 #define TWL4030_MADC_ADCIN0     (1 << 0)
  63 #define TWL4030_MADC_ADCIN1     (1 << 1)
  64 #define TWL4030_MADC_ADCIN2     (1 << 2)
  65 #define TWL4030_MADC_ADCIN3     (1 << 3)
  66 #define TWL4030_MADC_ADCIN4     (1 << 4)
  67 #define TWL4030_MADC_ADCIN5     (1 << 5)
  68 #define TWL4030_MADC_ADCIN6     (1 << 6)
  69 #define TWL4030_MADC_ADCIN7     (1 << 7)
  70 #define TWL4030_MADC_ADCIN8     (1 << 8)
  71 #define TWL4030_MADC_ADCIN9     (1 << 9)
  72 #define TWL4030_MADC_ADCIN10    (1 << 10)
  73 #define TWL4030_MADC_ADCIN11    (1 << 11)
  74 #define TWL4030_MADC_ADCIN12    (1 << 12)
  75 #define TWL4030_MADC_ADCIN13    (1 << 13)
  76 #define TWL4030_MADC_ADCIN14    (1 << 14)
  77 #define TWL4030_MADC_ADCIN15    (1 << 15)
  78 
  79 /* Fixed channels */
  80 #define TWL4030_MADC_BTEMP      TWL4030_MADC_ADCIN1
  81 #define TWL4030_MADC_VBUS       TWL4030_MADC_ADCIN8
  82 #define TWL4030_MADC_VBKB       TWL4030_MADC_ADCIN9
  83 #define TWL4030_MADC_ICHG       TWL4030_MADC_ADCIN10
  84 #define TWL4030_MADC_VCHG       TWL4030_MADC_ADCIN11
  85 #define TWL4030_MADC_VBAT       TWL4030_MADC_ADCIN12
  86 
  87 /* Step size and prescaler ratio */
  88 #define TEMP_STEP_SIZE          147
  89 #define TEMP_PSR_R              100
  90 #define CURR_STEP_SIZE          147
  91 #define CURR_PSR_R1             44
  92 #define CURR_PSR_R2             88
  93 
  94 #define TWL4030_BCI_BCICTL1     0x23
  95 #define TWL4030_BCI_CGAIN       0x020
  96 #define TWL4030_BCI_MESBAT      (1 << 1)
  97 #define TWL4030_BCI_TYPEN       (1 << 4)
  98 #define TWL4030_BCI_ITHEN       (1 << 3)
  99 
 100 #define REG_BCICTL2             0x024
 101 #define TWL4030_BCI_ITHSENS     0x007
 102 
 103 /* Register and bits for GPBR1 register */
 104 #define TWL4030_REG_GPBR1               0x0c
 105 #define TWL4030_GPBR1_MADC_HFCLK_EN     (1 << 7)
 106 
 107 #define TWL4030_USB_SEL_MADC_MCPC       (1<<3)
 108 #define TWL4030_USB_CARKIT_ANA_CTRL     0xBB
 109 
 110 struct twl4030_madc_conversion_method {
 111         u8 sel;
 112         u8 avg;
 113         u8 rbase;
 114         u8 ctrl;
 115 };
 116 
 117 /**
 118  * struct twl4030_madc_request - madc request packet for channel conversion
 119  * @channels:   16 bit bitmap for individual channels
 120  * @do_avg:     sample the input channel for 4 consecutive cycles
 121  * @method:     RT, SW1, SW2
 122  * @type:       Polling or interrupt based method
 123  * @active:     Flag if request is active
 124  * @result_pending: Flag from irq handler, that result is ready
 125  * @raw:        Return raw value, do not convert it
 126  * @rbuf:       Result buffer
 127  */
 128 struct twl4030_madc_request {
 129         unsigned long channels;
 130         bool do_avg;
 131         u16 method;
 132         u16 type;
 133         bool active;
 134         bool result_pending;
 135         bool raw;
 136         int rbuf[TWL4030_MADC_MAX_CHANNELS];
 137 };
 138 
 139 enum conversion_methods {
 140         TWL4030_MADC_RT,
 141         TWL4030_MADC_SW1,
 142         TWL4030_MADC_SW2,
 143         TWL4030_MADC_NUM_METHODS
 144 };
 145 
 146 enum sample_type {
 147         TWL4030_MADC_WAIT,
 148         TWL4030_MADC_IRQ_ONESHOT,
 149         TWL4030_MADC_IRQ_REARM
 150 };
 151 
 152 /**
 153  * struct twl4030_madc_data - a container for madc info
 154  * @dev:                Pointer to device structure for madc
 155  * @lock:               Mutex protecting this data structure
 156  * @regulator:          Pointer to bias regulator for madc
 157  * @requests:           Array of request struct corresponding to SW1, SW2 and RT
 158  * @use_second_irq:     IRQ selection (main or co-processor)
 159  * @imr:                Interrupt mask register of MADC
 160  * @isr:                Interrupt status register of MADC
 161  */
 162 struct twl4030_madc_data {
 163         struct device *dev;
 164         struct mutex lock;      /* mutex protecting this data structure */
 165         struct regulator *usb3v1;
 166         struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
 167         bool use_second_irq;
 168         u8 imr;
 169         u8 isr;
 170 };
 171 
 172 static int twl4030_madc_conversion(struct twl4030_madc_request *req);
 173 
 174 static int twl4030_madc_read(struct iio_dev *iio_dev,
 175                              const struct iio_chan_spec *chan,
 176                              int *val, int *val2, long mask)
 177 {
 178         struct twl4030_madc_data *madc = iio_priv(iio_dev);
 179         struct twl4030_madc_request req;
 180         int ret;
 181 
 182         req.method = madc->use_second_irq ? TWL4030_MADC_SW2 : TWL4030_MADC_SW1;
 183 
 184         req.channels = BIT(chan->channel);
 185         req.active = false;
 186         req.type = TWL4030_MADC_WAIT;
 187         req.raw = !(mask == IIO_CHAN_INFO_PROCESSED);
 188         req.do_avg = (mask == IIO_CHAN_INFO_AVERAGE_RAW);
 189 
 190         ret = twl4030_madc_conversion(&req);
 191         if (ret < 0)
 192                 return ret;
 193 
 194         *val = req.rbuf[chan->channel];
 195 
 196         return IIO_VAL_INT;
 197 }
 198 
 199 static const struct iio_info twl4030_madc_iio_info = {
 200         .read_raw = &twl4030_madc_read,
 201 };
 202 
 203 #define TWL4030_ADC_CHANNEL(_channel, _type, _name) {   \
 204         .type = _type,                                  \
 205         .channel = _channel,                            \
 206         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
 207                               BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
 208                               BIT(IIO_CHAN_INFO_PROCESSED), \
 209         .datasheet_name = _name,                        \
 210         .indexed = 1,                                   \
 211 }
 212 
 213 static const struct iio_chan_spec twl4030_madc_iio_channels[] = {
 214         TWL4030_ADC_CHANNEL(0, IIO_VOLTAGE, "ADCIN0"),
 215         TWL4030_ADC_CHANNEL(1, IIO_TEMP, "ADCIN1"),
 216         TWL4030_ADC_CHANNEL(2, IIO_VOLTAGE, "ADCIN2"),
 217         TWL4030_ADC_CHANNEL(3, IIO_VOLTAGE, "ADCIN3"),
 218         TWL4030_ADC_CHANNEL(4, IIO_VOLTAGE, "ADCIN4"),
 219         TWL4030_ADC_CHANNEL(5, IIO_VOLTAGE, "ADCIN5"),
 220         TWL4030_ADC_CHANNEL(6, IIO_VOLTAGE, "ADCIN6"),
 221         TWL4030_ADC_CHANNEL(7, IIO_VOLTAGE, "ADCIN7"),
 222         TWL4030_ADC_CHANNEL(8, IIO_VOLTAGE, "ADCIN8"),
 223         TWL4030_ADC_CHANNEL(9, IIO_VOLTAGE, "ADCIN9"),
 224         TWL4030_ADC_CHANNEL(10, IIO_CURRENT, "ADCIN10"),
 225         TWL4030_ADC_CHANNEL(11, IIO_VOLTAGE, "ADCIN11"),
 226         TWL4030_ADC_CHANNEL(12, IIO_VOLTAGE, "ADCIN12"),
 227         TWL4030_ADC_CHANNEL(13, IIO_VOLTAGE, "ADCIN13"),
 228         TWL4030_ADC_CHANNEL(14, IIO_VOLTAGE, "ADCIN14"),
 229         TWL4030_ADC_CHANNEL(15, IIO_VOLTAGE, "ADCIN15"),
 230 };
 231 
 232 static struct twl4030_madc_data *twl4030_madc;
 233 
 234 struct twl4030_prescale_divider_ratios {
 235         s16 numerator;
 236         s16 denominator;
 237 };
 238 
 239 static const struct twl4030_prescale_divider_ratios
 240 twl4030_divider_ratios[16] = {
 241         {1, 1},         /* CHANNEL 0 No Prescaler */
 242         {1, 1},         /* CHANNEL 1 No Prescaler */
 243         {6, 10},        /* CHANNEL 2 */
 244         {6, 10},        /* CHANNEL 3 */
 245         {6, 10},        /* CHANNEL 4 */
 246         {6, 10},        /* CHANNEL 5 */
 247         {6, 10},        /* CHANNEL 6 */
 248         {6, 10},        /* CHANNEL 7 */
 249         {3, 14},        /* CHANNEL 8 */
 250         {1, 3},         /* CHANNEL 9 */
 251         {1, 1},         /* CHANNEL 10 No Prescaler */
 252         {15, 100},      /* CHANNEL 11 */
 253         {1, 4},         /* CHANNEL 12 */
 254         {1, 1},         /* CHANNEL 13 Reserved channels */
 255         {1, 1},         /* CHANNEL 14 Reseved channels */
 256         {5, 11},        /* CHANNEL 15 */
 257 };
 258 
 259 
 260 /* Conversion table from -3 to 55 degrees Celcius */
 261 static int twl4030_therm_tbl[] = {
 262         30800,  29500,  28300,  27100,
 263         26000,  24900,  23900,  22900,  22000,  21100,  20300,  19400,  18700,
 264         17900,  17200,  16500,  15900,  15300,  14700,  14100,  13600,  13100,
 265         12600,  12100,  11600,  11200,  10800,  10400,  10000,  9630,   9280,
 266         8950,   8620,   8310,   8020,   7730,   7460,   7200,   6950,   6710,
 267         6470,   6250,   6040,   5830,   5640,   5450,   5260,   5090,   4920,
 268         4760,   4600,   4450,   4310,   4170,   4040,   3910,   3790,   3670,
 269         3550
 270 };
 271 
 272 /*
 273  * Structure containing the registers
 274  * of different conversion methods supported by MADC.
 275  * Hardware or RT real time conversion request initiated by external host
 276  * processor for RT Signal conversions.
 277  * External host processors can also request for non RT conversions
 278  * SW1 and SW2 software conversions also called asynchronous or GPC request.
 279  */
 280 static
 281 const struct twl4030_madc_conversion_method twl4030_conversion_methods[] = {
 282         [TWL4030_MADC_RT] = {
 283                              .sel = TWL4030_MADC_RTSELECT_LSB,
 284                              .avg = TWL4030_MADC_RTAVERAGE_LSB,
 285                              .rbase = TWL4030_MADC_RTCH0_LSB,
 286                              },
 287         [TWL4030_MADC_SW1] = {
 288                               .sel = TWL4030_MADC_SW1SELECT_LSB,
 289                               .avg = TWL4030_MADC_SW1AVERAGE_LSB,
 290                               .rbase = TWL4030_MADC_GPCH0_LSB,
 291                               .ctrl = TWL4030_MADC_CTRL_SW1,
 292                               },
 293         [TWL4030_MADC_SW2] = {
 294                               .sel = TWL4030_MADC_SW2SELECT_LSB,
 295                               .avg = TWL4030_MADC_SW2AVERAGE_LSB,
 296                               .rbase = TWL4030_MADC_GPCH0_LSB,
 297                               .ctrl = TWL4030_MADC_CTRL_SW2,
 298                               },
 299 };
 300 
 301 /**
 302  * twl4030_madc_channel_raw_read() - Function to read a particular channel value
 303  * @madc:       pointer to struct twl4030_madc_data
 304  * @reg:        lsb of ADC Channel
 305  *
 306  * Return: 0 on success, an error code otherwise.
 307  */
 308 static int twl4030_madc_channel_raw_read(struct twl4030_madc_data *madc, u8 reg)
 309 {
 310         u16 val;
 311         int ret;
 312         /*
 313          * For each ADC channel, we have MSB and LSB register pair. MSB address
 314          * is always LSB address+1. reg parameter is the address of LSB register
 315          */
 316         ret = twl_i2c_read_u16(TWL4030_MODULE_MADC, &val, reg);
 317         if (ret) {
 318                 dev_err(madc->dev, "unable to read register 0x%X\n", reg);
 319                 return ret;
 320         }
 321 
 322         return (int)(val >> 6);
 323 }
 324 
 325 /*
 326  * Return battery temperature in degrees Celsius
 327  * Or < 0 on failure.
 328  */
 329 static int twl4030battery_temperature(int raw_volt)
 330 {
 331         u8 val;
 332         int temp, curr, volt, res, ret;
 333 
 334         volt = (raw_volt * TEMP_STEP_SIZE) / TEMP_PSR_R;
 335         /* Getting and calculating the supply current in micro amperes */
 336         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val,
 337                 REG_BCICTL2);
 338         if (ret < 0)
 339                 return ret;
 340 
 341         curr = ((val & TWL4030_BCI_ITHSENS) + 1) * 10;
 342         /* Getting and calculating the thermistor resistance in ohms */
 343         res = volt * 1000 / curr;
 344         /* calculating temperature */
 345         for (temp = 58; temp >= 0; temp--) {
 346                 int actual = twl4030_therm_tbl[temp];
 347                 if ((actual - res) >= 0)
 348                         break;
 349         }
 350 
 351         return temp + 1;
 352 }
 353 
 354 static int twl4030battery_current(int raw_volt)
 355 {
 356         int ret;
 357         u8 val;
 358 
 359         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val,
 360                 TWL4030_BCI_BCICTL1);
 361         if (ret)
 362                 return ret;
 363         if (val & TWL4030_BCI_CGAIN) /* slope of 0.44 mV/mA */
 364                 return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R1;
 365         else /* slope of 0.88 mV/mA */
 366                 return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R2;
 367 }
 368 
 369 /*
 370  * Function to read channel values
 371  * @madc - pointer to twl4030_madc_data struct
 372  * @reg_base - Base address of the first channel
 373  * @Channels - 16 bit bitmap. If the bit is set, channel's value is read
 374  * @buf - The channel values are stored here. if read fails error
 375  * @raw - Return raw values without conversion
 376  * value is stored
 377  * Returns the number of successfully read channels.
 378  */
 379 static int twl4030_madc_read_channels(struct twl4030_madc_data *madc,
 380                                       u8 reg_base, unsigned
 381                                       long channels, int *buf,
 382                                       bool raw)
 383 {
 384         int count = 0;
 385         int i;
 386         u8 reg;
 387 
 388         for_each_set_bit(i, &channels, TWL4030_MADC_MAX_CHANNELS) {
 389                 reg = reg_base + (2 * i);
 390                 buf[i] = twl4030_madc_channel_raw_read(madc, reg);
 391                 if (buf[i] < 0) {
 392                         dev_err(madc->dev, "Unable to read register 0x%X\n",
 393                                 reg);
 394                         return buf[i];
 395                 }
 396                 if (raw) {
 397                         count++;
 398                         continue;
 399                 }
 400                 switch (i) {
 401                 case 10:
 402                         buf[i] = twl4030battery_current(buf[i]);
 403                         if (buf[i] < 0) {
 404                                 dev_err(madc->dev, "err reading current\n");
 405                                 return buf[i];
 406                         } else {
 407                                 count++;
 408                                 buf[i] = buf[i] - 750;
 409                         }
 410                         break;
 411                 case 1:
 412                         buf[i] = twl4030battery_temperature(buf[i]);
 413                         if (buf[i] < 0) {
 414                                 dev_err(madc->dev, "err reading temperature\n");
 415                                 return buf[i];
 416                         } else {
 417                                 buf[i] -= 3;
 418                                 count++;
 419                         }
 420                         break;
 421                 default:
 422                         count++;
 423                         /* Analog Input (V) = conv_result * step_size / R
 424                          * conv_result = decimal value of 10-bit conversion
 425                          *               result
 426                          * step size = 1.5 / (2 ^ 10 -1)
 427                          * R = Prescaler ratio for input channels.
 428                          * Result given in mV hence multiplied by 1000.
 429                          */
 430                         buf[i] = (buf[i] * 3 * 1000 *
 431                                  twl4030_divider_ratios[i].denominator)
 432                                 / (2 * 1023 *
 433                                 twl4030_divider_ratios[i].numerator);
 434                 }
 435         }
 436 
 437         return count;
 438 }
 439 
 440 /*
 441  * Disables irq.
 442  * @madc - pointer to twl4030_madc_data struct
 443  * @id - irq number to be disabled
 444  * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2
 445  * corresponding to RT, SW1, SW2 conversion requests.
 446  * Returns error if i2c read/write fails.
 447  */
 448 static int twl4030_madc_disable_irq(struct twl4030_madc_data *madc, u8 id)
 449 {
 450         u8 val;
 451         int ret;
 452 
 453         ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr);
 454         if (ret) {
 455                 dev_err(madc->dev, "unable to read imr register 0x%X\n",
 456                         madc->imr);
 457                 return ret;
 458         }
 459         val |= (1 << id);
 460         ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr);
 461         if (ret) {
 462                 dev_err(madc->dev,
 463                         "unable to write imr register 0x%X\n", madc->imr);
 464                 return ret;
 465         }
 466 
 467         return 0;
 468 }
 469 
 470 static irqreturn_t twl4030_madc_threaded_irq_handler(int irq, void *_madc)
 471 {
 472         struct twl4030_madc_data *madc = _madc;
 473         const struct twl4030_madc_conversion_method *method;
 474         u8 isr_val, imr_val;
 475         int i, len, ret;
 476         struct twl4030_madc_request *r;
 477 
 478         mutex_lock(&madc->lock);
 479         ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &isr_val, madc->isr);
 480         if (ret) {
 481                 dev_err(madc->dev, "unable to read isr register 0x%X\n",
 482                         madc->isr);
 483                 goto err_i2c;
 484         }
 485         ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &imr_val, madc->imr);
 486         if (ret) {
 487                 dev_err(madc->dev, "unable to read imr register 0x%X\n",
 488                         madc->imr);
 489                 goto err_i2c;
 490         }
 491         isr_val &= ~imr_val;
 492         for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
 493                 if (!(isr_val & (1 << i)))
 494                         continue;
 495                 ret = twl4030_madc_disable_irq(madc, i);
 496                 if (ret < 0)
 497                         dev_dbg(madc->dev, "Disable interrupt failed %d\n", i);
 498                 madc->requests[i].result_pending = 1;
 499         }
 500         for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
 501                 r = &madc->requests[i];
 502                 /* No pending results for this method, move to next one */
 503                 if (!r->result_pending)
 504                         continue;
 505                 method = &twl4030_conversion_methods[r->method];
 506                 /* Read results */
 507                 len = twl4030_madc_read_channels(madc, method->rbase,
 508                                                  r->channels, r->rbuf, r->raw);
 509                 /* Free request */
 510                 r->result_pending = 0;
 511                 r->active = 0;
 512         }
 513         mutex_unlock(&madc->lock);
 514 
 515         return IRQ_HANDLED;
 516 
 517 err_i2c:
 518         /*
 519          * In case of error check whichever request is active
 520          * and service the same.
 521          */
 522         for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
 523                 r = &madc->requests[i];
 524                 if (r->active == 0)
 525                         continue;
 526                 method = &twl4030_conversion_methods[r->method];
 527                 /* Read results */
 528                 len = twl4030_madc_read_channels(madc, method->rbase,
 529                                                  r->channels, r->rbuf, r->raw);
 530                 /* Free request */
 531                 r->result_pending = 0;
 532                 r->active = 0;
 533         }
 534         mutex_unlock(&madc->lock);
 535 
 536         return IRQ_HANDLED;
 537 }
 538 
 539 /*
 540  * Function which enables the madc conversion
 541  * by writing to the control register.
 542  * @madc - pointer to twl4030_madc_data struct
 543  * @conv_method - can be TWL4030_MADC_RT, TWL4030_MADC_SW2, TWL4030_MADC_SW1
 544  * corresponding to RT SW1 or SW2 conversion methods.
 545  * Returns 0 if succeeds else a negative error value
 546  */
 547 static int twl4030_madc_start_conversion(struct twl4030_madc_data *madc,
 548                                          int conv_method)
 549 {
 550         const struct twl4030_madc_conversion_method *method;
 551         int ret = 0;
 552 
 553         if (conv_method != TWL4030_MADC_SW1 && conv_method != TWL4030_MADC_SW2)
 554                 return -ENOTSUPP;
 555 
 556         method = &twl4030_conversion_methods[conv_method];
 557         ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, TWL4030_MADC_SW_START,
 558                                method->ctrl);
 559         if (ret) {
 560                 dev_err(madc->dev, "unable to write ctrl register 0x%X\n",
 561                         method->ctrl);
 562                 return ret;
 563         }
 564 
 565         return 0;
 566 }
 567 
 568 /*
 569  * Function that waits for conversion to be ready
 570  * @madc - pointer to twl4030_madc_data struct
 571  * @timeout_ms - timeout value in milliseconds
 572  * @status_reg - ctrl register
 573  * returns 0 if succeeds else a negative error value
 574  */
 575 static int twl4030_madc_wait_conversion_ready(struct twl4030_madc_data *madc,
 576                                               unsigned int timeout_ms,
 577                                               u8 status_reg)
 578 {
 579         unsigned long timeout;
 580         int ret;
 581 
 582         timeout = jiffies + msecs_to_jiffies(timeout_ms);
 583         do {
 584                 u8 reg;
 585 
 586                 ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &reg, status_reg);
 587                 if (ret) {
 588                         dev_err(madc->dev,
 589                                 "unable to read status register 0x%X\n",
 590                                 status_reg);
 591                         return ret;
 592                 }
 593                 if (!(reg & TWL4030_MADC_BUSY) && (reg & TWL4030_MADC_EOC_SW))
 594                         return 0;
 595                 usleep_range(500, 2000);
 596         } while (!time_after(jiffies, timeout));
 597         dev_err(madc->dev, "conversion timeout!\n");
 598 
 599         return -EAGAIN;
 600 }
 601 
 602 /*
 603  * An exported function which can be called from other kernel drivers.
 604  * @req twl4030_madc_request structure
 605  * req->rbuf will be filled with read values of channels based on the
 606  * channel index. If a particular channel reading fails there will
 607  * be a negative error value in the corresponding array element.
 608  * returns 0 if succeeds else error value
 609  */
 610 static int twl4030_madc_conversion(struct twl4030_madc_request *req)
 611 {
 612         const struct twl4030_madc_conversion_method *method;
 613         int ret;
 614 
 615         if (!req || !twl4030_madc)
 616                 return -EINVAL;
 617 
 618         mutex_lock(&twl4030_madc->lock);
 619         if (req->method < TWL4030_MADC_RT || req->method > TWL4030_MADC_SW2) {
 620                 ret = -EINVAL;
 621                 goto out;
 622         }
 623         /* Do we have a conversion request ongoing */
 624         if (twl4030_madc->requests[req->method].active) {
 625                 ret = -EBUSY;
 626                 goto out;
 627         }
 628         method = &twl4030_conversion_methods[req->method];
 629         /* Select channels to be converted */
 630         ret = twl_i2c_write_u16(TWL4030_MODULE_MADC, req->channels, method->sel);
 631         if (ret) {
 632                 dev_err(twl4030_madc->dev,
 633                         "unable to write sel register 0x%X\n", method->sel);
 634                 goto out;
 635         }
 636         /* Select averaging for all channels if do_avg is set */
 637         if (req->do_avg) {
 638                 ret = twl_i2c_write_u16(TWL4030_MODULE_MADC, req->channels,
 639                                        method->avg);
 640                 if (ret) {
 641                         dev_err(twl4030_madc->dev,
 642                                 "unable to write avg register 0x%X\n",
 643                                 method->avg);
 644                         goto out;
 645                 }
 646         }
 647         /* With RT method we should not be here anymore */
 648         if (req->method == TWL4030_MADC_RT) {
 649                 ret = -EINVAL;
 650                 goto out;
 651         }
 652         ret = twl4030_madc_start_conversion(twl4030_madc, req->method);
 653         if (ret < 0)
 654                 goto out;
 655         twl4030_madc->requests[req->method].active = 1;
 656         /* Wait until conversion is ready (ctrl register returns EOC) */
 657         ret = twl4030_madc_wait_conversion_ready(twl4030_madc, 5, method->ctrl);
 658         if (ret) {
 659                 twl4030_madc->requests[req->method].active = 0;
 660                 goto out;
 661         }
 662         ret = twl4030_madc_read_channels(twl4030_madc, method->rbase,
 663                                          req->channels, req->rbuf, req->raw);
 664         twl4030_madc->requests[req->method].active = 0;
 665 
 666 out:
 667         mutex_unlock(&twl4030_madc->lock);
 668 
 669         return ret;
 670 }
 671 
 672 /**
 673  * twl4030_madc_set_current_generator() - setup bias current
 674  *
 675  * @madc:       pointer to twl4030_madc_data struct
 676  * @chan:       can be one of the two values:
 677  *              0 - Enables bias current for main battery type reading
 678  *              1 - Enables bias current for main battery temperature sensing
 679  * @on:         enable or disable chan.
 680  *
 681  * Function to enable or disable bias current for
 682  * main battery type reading or temperature sensing
 683  */
 684 static int twl4030_madc_set_current_generator(struct twl4030_madc_data *madc,
 685                                               int chan, int on)
 686 {
 687         int ret;
 688         int regmask;
 689         u8 regval;
 690 
 691         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
 692                               &regval, TWL4030_BCI_BCICTL1);
 693         if (ret) {
 694                 dev_err(madc->dev, "unable to read BCICTL1 reg 0x%X",
 695                         TWL4030_BCI_BCICTL1);
 696                 return ret;
 697         }
 698 
 699         regmask = chan ? TWL4030_BCI_ITHEN : TWL4030_BCI_TYPEN;
 700         if (on)
 701                 regval |= regmask;
 702         else
 703                 regval &= ~regmask;
 704 
 705         ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
 706                                regval, TWL4030_BCI_BCICTL1);
 707         if (ret) {
 708                 dev_err(madc->dev, "unable to write BCICTL1 reg 0x%X\n",
 709                         TWL4030_BCI_BCICTL1);
 710                 return ret;
 711         }
 712 
 713         return 0;
 714 }
 715 
 716 /*
 717  * Function that sets MADC software power on bit to enable MADC
 718  * @madc - pointer to twl4030_madc_data struct
 719  * @on - Enable or disable MADC software power on bit.
 720  * returns error if i2c read/write fails else 0
 721  */
 722 static int twl4030_madc_set_power(struct twl4030_madc_data *madc, int on)
 723 {
 724         u8 regval;
 725         int ret;
 726 
 727         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
 728                               &regval, TWL4030_MADC_CTRL1);
 729         if (ret) {
 730                 dev_err(madc->dev, "unable to read madc ctrl1 reg 0x%X\n",
 731                         TWL4030_MADC_CTRL1);
 732                 return ret;
 733         }
 734         if (on)
 735                 regval |= TWL4030_MADC_MADCON;
 736         else
 737                 regval &= ~TWL4030_MADC_MADCON;
 738         ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, regval, TWL4030_MADC_CTRL1);
 739         if (ret) {
 740                 dev_err(madc->dev, "unable to write madc ctrl1 reg 0x%X\n",
 741                         TWL4030_MADC_CTRL1);
 742                 return ret;
 743         }
 744 
 745         return 0;
 746 }
 747 
 748 /*
 749  * Initialize MADC and request for threaded irq
 750  */
 751 static int twl4030_madc_probe(struct platform_device *pdev)
 752 {
 753         struct twl4030_madc_data *madc;
 754         struct twl4030_madc_platform_data *pdata = dev_get_platdata(&pdev->dev);
 755         struct device_node *np = pdev->dev.of_node;
 756         int irq, ret;
 757         u8 regval;
 758         struct iio_dev *iio_dev = NULL;
 759 
 760         if (!pdata && !np) {
 761                 dev_err(&pdev->dev, "neither platform data nor Device Tree node available\n");
 762                 return -EINVAL;
 763         }
 764 
 765         iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*madc));
 766         if (!iio_dev) {
 767                 dev_err(&pdev->dev, "failed allocating iio device\n");
 768                 return -ENOMEM;
 769         }
 770 
 771         madc = iio_priv(iio_dev);
 772         madc->dev = &pdev->dev;
 773 
 774         iio_dev->name = dev_name(&pdev->dev);
 775         iio_dev->dev.parent = &pdev->dev;
 776         iio_dev->dev.of_node = pdev->dev.of_node;
 777         iio_dev->info = &twl4030_madc_iio_info;
 778         iio_dev->modes = INDIO_DIRECT_MODE;
 779         iio_dev->channels = twl4030_madc_iio_channels;
 780         iio_dev->num_channels = ARRAY_SIZE(twl4030_madc_iio_channels);
 781 
 782         /*
 783          * Phoenix provides 2 interrupt lines. The first one is connected to
 784          * the OMAP. The other one can be connected to the other processor such
 785          * as modem. Hence two separate ISR and IMR registers.
 786          */
 787         if (pdata)
 788                 madc->use_second_irq = (pdata->irq_line != 1);
 789         else
 790                 madc->use_second_irq = of_property_read_bool(np,
 791                                        "ti,system-uses-second-madc-irq");
 792 
 793         madc->imr = madc->use_second_irq ? TWL4030_MADC_IMR2 :
 794                                            TWL4030_MADC_IMR1;
 795         madc->isr = madc->use_second_irq ? TWL4030_MADC_ISR2 :
 796                                            TWL4030_MADC_ISR1;
 797 
 798         ret = twl4030_madc_set_power(madc, 1);
 799         if (ret < 0)
 800                 return ret;
 801         ret = twl4030_madc_set_current_generator(madc, 0, 1);
 802         if (ret < 0)
 803                 goto err_current_generator;
 804 
 805         ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
 806                               &regval, TWL4030_BCI_BCICTL1);
 807         if (ret) {
 808                 dev_err(&pdev->dev, "unable to read reg BCI CTL1 0x%X\n",
 809                         TWL4030_BCI_BCICTL1);
 810                 goto err_i2c;
 811         }
 812         regval |= TWL4030_BCI_MESBAT;
 813         ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
 814                                regval, TWL4030_BCI_BCICTL1);
 815         if (ret) {
 816                 dev_err(&pdev->dev, "unable to write reg BCI Ctl1 0x%X\n",
 817                         TWL4030_BCI_BCICTL1);
 818                 goto err_i2c;
 819         }
 820 
 821         /* Check that MADC clock is on */
 822         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &regval, TWL4030_REG_GPBR1);
 823         if (ret) {
 824                 dev_err(&pdev->dev, "unable to read reg GPBR1 0x%X\n",
 825                                 TWL4030_REG_GPBR1);
 826                 goto err_i2c;
 827         }
 828 
 829         /* If MADC clk is not on, turn it on */
 830         if (!(regval & TWL4030_GPBR1_MADC_HFCLK_EN)) {
 831                 dev_info(&pdev->dev, "clk disabled, enabling\n");
 832                 regval |= TWL4030_GPBR1_MADC_HFCLK_EN;
 833                 ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, regval,
 834                                        TWL4030_REG_GPBR1);
 835                 if (ret) {
 836                         dev_err(&pdev->dev, "unable to write reg GPBR1 0x%X\n",
 837                                         TWL4030_REG_GPBR1);
 838                         goto err_i2c;
 839                 }
 840         }
 841 
 842         platform_set_drvdata(pdev, iio_dev);
 843         mutex_init(&madc->lock);
 844 
 845         irq = platform_get_irq(pdev, 0);
 846         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 847                                    twl4030_madc_threaded_irq_handler,
 848                                    IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 849                                    "twl4030_madc", madc);
 850         if (ret) {
 851                 dev_err(&pdev->dev, "could not request irq\n");
 852                 goto err_i2c;
 853         }
 854         twl4030_madc = madc;
 855 
 856         /* Configure MADC[3:6] */
 857         ret = twl_i2c_read_u8(TWL_MODULE_USB, &regval,
 858                         TWL4030_USB_CARKIT_ANA_CTRL);
 859         if (ret) {
 860                 dev_err(&pdev->dev, "unable to read reg CARKIT_ANA_CTRL  0x%X\n",
 861                                 TWL4030_USB_CARKIT_ANA_CTRL);
 862                 goto err_i2c;
 863         }
 864         regval |= TWL4030_USB_SEL_MADC_MCPC;
 865         ret = twl_i2c_write_u8(TWL_MODULE_USB, regval,
 866                                  TWL4030_USB_CARKIT_ANA_CTRL);
 867         if (ret) {
 868                 dev_err(&pdev->dev, "unable to write reg CARKIT_ANA_CTRL 0x%X\n",
 869                                 TWL4030_USB_CARKIT_ANA_CTRL);
 870                 goto err_i2c;
 871         }
 872 
 873         /* Enable 3v1 bias regulator for MADC[3:6] */
 874         madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
 875         if (IS_ERR(madc->usb3v1)) {
 876                 ret = -ENODEV;
 877                 goto err_i2c;
 878         }
 879 
 880         ret = regulator_enable(madc->usb3v1);
 881         if (ret) {
 882                 dev_err(madc->dev, "could not enable 3v1 bias regulator\n");
 883                 goto err_i2c;
 884         }
 885 
 886         ret = iio_device_register(iio_dev);
 887         if (ret) {
 888                 dev_err(&pdev->dev, "could not register iio device\n");
 889                 goto err_usb3v1;
 890         }
 891 
 892         return 0;
 893 
 894 err_usb3v1:
 895         regulator_disable(madc->usb3v1);
 896 err_i2c:
 897         twl4030_madc_set_current_generator(madc, 0, 0);
 898 err_current_generator:
 899         twl4030_madc_set_power(madc, 0);
 900         return ret;
 901 }
 902 
 903 static int twl4030_madc_remove(struct platform_device *pdev)
 904 {
 905         struct iio_dev *iio_dev = platform_get_drvdata(pdev);
 906         struct twl4030_madc_data *madc = iio_priv(iio_dev);
 907 
 908         iio_device_unregister(iio_dev);
 909 
 910         twl4030_madc_set_current_generator(madc, 0, 0);
 911         twl4030_madc_set_power(madc, 0);
 912 
 913         regulator_disable(madc->usb3v1);
 914 
 915         return 0;
 916 }
 917 
 918 #ifdef CONFIG_OF
 919 static const struct of_device_id twl_madc_of_match[] = {
 920         { .compatible = "ti,twl4030-madc", },
 921         { },
 922 };
 923 MODULE_DEVICE_TABLE(of, twl_madc_of_match);
 924 #endif
 925 
 926 static struct platform_driver twl4030_madc_driver = {
 927         .probe = twl4030_madc_probe,
 928         .remove = twl4030_madc_remove,
 929         .driver = {
 930                    .name = "twl4030_madc",
 931                    .of_match_table = of_match_ptr(twl_madc_of_match),
 932         },
 933 };
 934 
 935 module_platform_driver(twl4030_madc_driver);
 936 
 937 MODULE_DESCRIPTION("TWL4030 ADC driver");
 938 MODULE_LICENSE("GPL");
 939 MODULE_AUTHOR("J Keerthy");
 940 MODULE_ALIAS("platform:twl4030_madc");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/iio/adc/twl4030-madc.c

DEFINITIONS
