drivers/iio/adc/ti_am335x_adc.c

   1 /*
   2  * TI ADC MFD driver
   3  *
   4  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation version 2.
   9  *
  10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  11  * kind, whether express or implied; without even the implied warranty
  12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/err.h>
  18 #include <linux/module.h>
  19 #include <linux/slab.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/io.h>
  23 #include <linux/iio/iio.h>
  24 #include <linux/of.h>
  25 #include <linux/of_device.h>
  26 #include <linux/iio/machine.h>
  27 #include <linux/iio/driver.h>
  28
  29 #include <linux/mfd/ti_am335x_tscadc.h>
  30 #include <linux/iio/buffer.h>
  31 #include <linux/iio/kfifo_buf.h>
  32
  33 #include <linux/dmaengine.h>
  34 #include <linux/dma-mapping.h>
  35
  36 #define DMA_BUFFER_SIZE         SZ_2K
  37
  38 struct tiadc_dma {
  39         struct dma_slave_config conf;
  40         struct dma_chan         *chan;
  41         dma_addr_t              addr;
  42         dma_cookie_t            cookie;
  43         u8                      *buf;
  44         int                     current_period;
  45         int                     period_size;
  46         u8                      fifo_thresh;
  47 };
  48
  49 struct tiadc_device {
  50         struct ti_tscadc_dev *mfd_tscadc;
  51         struct tiadc_dma dma;
  52         struct mutex fifo1_lock; /* to protect fifo access */
  53         int channels;
  54         int total_ch_enabled;
  55         u8 channel_line[8];
  56         u8 channel_step[8];
  57         int buffer_en_ch_steps;
  58         u16 data[8];
  59         u32 open_delay[8], sample_delay[8], step_avg[8];
  60 };
  61
  62 static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
  63 {
  64         return readl(adc->mfd_tscadc->tscadc_base + reg);
  65 }
  66
  67 static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
  68                                         unsigned int val)
  69 {
  70         writel(val, adc->mfd_tscadc->tscadc_base + reg);
  71 }
  72
  73 static u32 get_adc_step_mask(struct tiadc_device *adc_dev)
  74 {
  75         u32 step_en;
  76
  77         step_en = ((1 << adc_dev->channels) - 1);
  78         step_en <<= TOTAL_STEPS - adc_dev->channels + 1;
  79         return step_en;
  80 }
  81
  82 static u32 get_adc_chan_step_mask(struct tiadc_device *adc_dev,
  83                 struct iio_chan_spec const *chan)
  84 {
  85         int i;
  86
  87         for (i = 0; i < ARRAY_SIZE(adc_dev->channel_step); i++) {
  88                 if (chan->channel == adc_dev->channel_line[i]) {
  89                         u32 step;
  90
  91                         step = adc_dev->channel_step[i];
  92                         /* +1 for the charger */
  93                         return 1 << (step + 1);
  94                 }
  95         }
  96         WARN_ON(1);
  97         return 0;
  98 }
  99
 100 static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan)
 101 {
 102         return 1 << adc_dev->channel_step[chan];
 103 }
 104
 105 static void tiadc_step_config(struct iio_dev *indio_dev)
 106 {
 107         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 108         struct device *dev = adc_dev->mfd_tscadc->dev;
 109         unsigned int stepconfig;
 110         int i, steps = 0;
 111
 112         /*
 113          * There are 16 configurable steps and 8 analog input
 114          * lines available which are shared between Touchscreen and ADC.
 115          *
 116          * Steps forwards i.e. from 0 towards 16 are used by ADC
 117          * depending on number of input lines needed.
 118          * Channel would represent which analog input
 119          * needs to be given to ADC to digitalize data.
 120          */
 121
 122
 123         for (i = 0; i < adc_dev->channels; i++) {
 124                 int chan;
 125
 126                 chan = adc_dev->channel_line[i];
 127
 128                 if (adc_dev->step_avg[i] > STEPCONFIG_AVG_16) {
 129                         dev_warn(dev, "chan %d step_avg truncating to %d\n",
 130                                  chan, STEPCONFIG_AVG_16);
 131                         adc_dev->step_avg[i] = STEPCONFIG_AVG_16;
 132                 }
 133
 134                 if (adc_dev->step_avg[i])
 135                         stepconfig =
 136                         STEPCONFIG_AVG(ffs(adc_dev->step_avg[i]) - 1) |
 137                         STEPCONFIG_FIFO1;
 138                 else
 139                         stepconfig = STEPCONFIG_FIFO1;
 140
 141                 if (iio_buffer_enabled(indio_dev))
 142                         stepconfig |= STEPCONFIG_MODE_SWCNT;
 143
 144                 tiadc_writel(adc_dev, REG_STEPCONFIG(steps),
 145                                 stepconfig | STEPCONFIG_INP(chan));
 146
 147                 if (adc_dev->open_delay[i] > STEPDELAY_OPEN_MASK) {
 148                         dev_warn(dev, "chan %d open delay truncating to 0x3FFFF\n",
 149                                  chan);
 150                         adc_dev->open_delay[i] = STEPDELAY_OPEN_MASK;
 151                 }
 152
 153                 if (adc_dev->sample_delay[i] > 0xFF) {
 154                         dev_warn(dev, "chan %d sample delay truncating to 0xFF\n",
 155                                  chan);
 156                         adc_dev->sample_delay[i] = 0xFF;
 157                 }
 158
 159                 tiadc_writel(adc_dev, REG_STEPDELAY(steps),
 160                                 STEPDELAY_OPEN(adc_dev->open_delay[i]) |
 161                                 STEPDELAY_SAMPLE(adc_dev->sample_delay[i]));
 162
 163                 adc_dev->channel_step[i] = steps;
 164                 steps++;
 165         }
 166 }
 167
 168 static irqreturn_t tiadc_irq_h(int irq, void *private)
 169 {
 170         struct iio_dev *indio_dev = private;
 171         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 172         unsigned int status, config, adc_fsm;
 173         unsigned short count = 0;
 174
 175         status = tiadc_readl(adc_dev, REG_IRQSTATUS);
 176
 177         /*
 178          * ADC and touchscreen share the IRQ line.
 179          * FIFO0 interrupts are used by TSC. Handle FIFO1 IRQs here only
 180          */
 181         if (status & IRQENB_FIFO1OVRRUN) {
 182                 /* FIFO Overrun. Clear flag. Disable/Enable ADC to recover */
 183                 config = tiadc_readl(adc_dev, REG_CTRL);
 184                 config &= ~(CNTRLREG_TSCSSENB);
 185                 tiadc_writel(adc_dev, REG_CTRL, config);
 186                 tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1OVRRUN
 187                                 | IRQENB_FIFO1UNDRFLW | IRQENB_FIFO1THRES);
 188
 189                 /* wait for idle state.
 190                  * ADC needs to finish the current conversion
 191                  * before disabling the module
 192                  */
 193                 do {
 194                         adc_fsm = tiadc_readl(adc_dev, REG_ADCFSM);
 195                 } while (adc_fsm != 0x10 && count++ < 100);
 196
 197                 tiadc_writel(adc_dev, REG_CTRL, (config | CNTRLREG_TSCSSENB));
 198                 return IRQ_HANDLED;
 199         } else if (status & IRQENB_FIFO1THRES) {
 200                 /* Disable irq and wake worker thread */
 201                 tiadc_writel(adc_dev, REG_IRQCLR, IRQENB_FIFO1THRES);
 202                 return IRQ_WAKE_THREAD;
 203         }
 204
 205         return IRQ_NONE;
 206 }
 207
 208 static irqreturn_t tiadc_worker_h(int irq, void *private)
 209 {
 210         struct iio_dev *indio_dev = private;
 211         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 212         int i, k, fifo1count, read;
 213         u16 *data = adc_dev->data;
 214
 215         fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
 216         for (k = 0; k < fifo1count; k = k + i) {
 217                 for (i = 0; i < (indio_dev->scan_bytes)/2; i++) {
 218                         read = tiadc_readl(adc_dev, REG_FIFO1);
 219                         data[i] = read & FIFOREAD_DATA_MASK;
 220                 }
 221                 iio_push_to_buffers(indio_dev, (u8 *) data);
 222         }
 223
 224         tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES);
 225         tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_FIFO1THRES);
 226
 227         return IRQ_HANDLED;
 228 }
 229
 230 static void tiadc_dma_rx_complete(void *param)
 231 {
 232         struct iio_dev *indio_dev = param;
 233         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 234         struct tiadc_dma *dma = &adc_dev->dma;
 235         u8 *data;
 236         int i;
 237
 238         data = dma->buf + dma->current_period * dma->period_size;
 239         dma->current_period = 1 - dma->current_period; /* swap the buffer ID */
 240
 241         for (i = 0; i < dma->period_size; i += indio_dev->scan_bytes) {
 242                 iio_push_to_buffers(indio_dev, data);
 243                 data += indio_dev->scan_bytes;
 244         }
 245 }
 246
 247 static int tiadc_start_dma(struct iio_dev *indio_dev)
 248 {
 249         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 250         struct tiadc_dma *dma = &adc_dev->dma;
 251         struct dma_async_tx_descriptor *desc;
 252
 253         dma->current_period = 0; /* We start to fill period 0 */
 254         /*
 255          * Make the fifo thresh as the multiple of total number of
 256          * channels enabled, so make sure that cyclic DMA period
 257          * length is also a multiple of total number of channels
 258          * enabled. This ensures that no invalid data is reported
 259          * to the stack via iio_push_to_buffers().
 260          */
 261         dma->fifo_thresh = rounddown(FIFO1_THRESHOLD + 1,
 262                                      adc_dev->total_ch_enabled) - 1;
 263         /* Make sure that period length is multiple of fifo thresh level */
 264         dma->period_size = rounddown(DMA_BUFFER_SIZE / 2,
 265                                     (dma->fifo_thresh + 1) * sizeof(u16));
 266
 267         dma->conf.src_maxburst = dma->fifo_thresh + 1;
 268         dmaengine_slave_config(dma->chan, &dma->conf);
 269
 270         desc = dmaengine_prep_dma_cyclic(dma->chan, dma->addr,
 271                                          dma->period_size * 2,
 272                                          dma->period_size, DMA_DEV_TO_MEM,
 273                                          DMA_PREP_INTERRUPT);
 274         if (!desc)
 275                 return -EBUSY;
 276
 277         desc->callback = tiadc_dma_rx_complete;
 278         desc->callback_param = indio_dev;
 279
 280         dma->cookie = dmaengine_submit(desc);
 281
 282         dma_async_issue_pending(dma->chan);
 283
 284         tiadc_writel(adc_dev, REG_FIFO1THR, dma->fifo_thresh);
 285         tiadc_writel(adc_dev, REG_DMA1REQ, dma->fifo_thresh);
 286         tiadc_writel(adc_dev, REG_DMAENABLE_SET, DMA_FIFO1);
 287
 288         return 0;
 289 }
 290
 291 static int tiadc_buffer_preenable(struct iio_dev *indio_dev)
 292 {
 293         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 294         int i, fifo1count, read;
 295
 296         tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
 297                                 IRQENB_FIFO1OVRRUN |
 298                                 IRQENB_FIFO1UNDRFLW));
 299
 300         /* Flush FIFO. Needed in corner cases in simultaneous tsc/adc use */
 301         fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
 302         for (i = 0; i < fifo1count; i++)
 303                 read = tiadc_readl(adc_dev, REG_FIFO1);
 304
 305         return 0;
 306 }
 307
 308 static int tiadc_buffer_postenable(struct iio_dev *indio_dev)
 309 {
 310         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 311         struct tiadc_dma *dma = &adc_dev->dma;
 312         unsigned int irq_enable;
 313         unsigned int enb = 0;
 314         u8 bit;
 315
 316         tiadc_step_config(indio_dev);
 317         for_each_set_bit(bit, indio_dev->active_scan_mask, adc_dev->channels) {
 318                 enb |= (get_adc_step_bit(adc_dev, bit) << 1);
 319                 adc_dev->total_ch_enabled++;
 320         }
 321         adc_dev->buffer_en_ch_steps = enb;
 322
 323         if (dma->chan)
 324                 tiadc_start_dma(indio_dev);
 325
 326         am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb);
 327
 328         tiadc_writel(adc_dev,  REG_IRQSTATUS, IRQENB_FIFO1THRES
 329                                 | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW);
 330
 331         irq_enable = IRQENB_FIFO1OVRRUN;
 332         if (!dma->chan)
 333                 irq_enable |= IRQENB_FIFO1THRES;
 334         tiadc_writel(adc_dev,  REG_IRQENABLE, irq_enable);
 335
 336         return 0;
 337 }
 338
 339 static int tiadc_buffer_predisable(struct iio_dev *indio_dev)
 340 {
 341         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 342         struct tiadc_dma *dma = &adc_dev->dma;
 343         int fifo1count, i, read;
 344
 345         tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
 346                                 IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW));
 347         am335x_tsc_se_clr(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps);
 348         adc_dev->buffer_en_ch_steps = 0;
 349         adc_dev->total_ch_enabled = 0;
 350         if (dma->chan) {
 351                 tiadc_writel(adc_dev, REG_DMAENABLE_CLEAR, 0x2);
 352                 dmaengine_terminate_async(dma->chan);
 353         }
 354
 355         /* Flush FIFO of leftover data in the time it takes to disable adc */
 356         fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
 357         for (i = 0; i < fifo1count; i++)
 358                 read = tiadc_readl(adc_dev, REG_FIFO1);
 359
 360         return 0;
 361 }
 362
 363 static int tiadc_buffer_postdisable(struct iio_dev *indio_dev)
 364 {
 365         tiadc_step_config(indio_dev);
 366
 367         return 0;
 368 }
 369
 370 static const struct iio_buffer_setup_ops tiadc_buffer_setup_ops = {
 371         .preenable = &tiadc_buffer_preenable,
 372         .postenable = &tiadc_buffer_postenable,
 373         .predisable = &tiadc_buffer_predisable,
 374         .postdisable = &tiadc_buffer_postdisable,
 375 };
 376
 377 static int tiadc_iio_buffered_hardware_setup(struct iio_dev *indio_dev,
 378         irqreturn_t (*pollfunc_bh)(int irq, void *p),
 379         irqreturn_t (*pollfunc_th)(int irq, void *p),
 380         int irq,
 381         unsigned long flags,
 382         const struct iio_buffer_setup_ops *setup_ops)
 383 {
 384         struct iio_buffer *buffer;
 385         int ret;
 386
 387         buffer = iio_kfifo_allocate();
 388         if (!buffer)
 389                 return -ENOMEM;
 390
 391         iio_device_attach_buffer(indio_dev, buffer);
 392
 393         ret = request_threaded_irq(irq, pollfunc_th, pollfunc_bh,
 394                                 flags, indio_dev->name, indio_dev);
 395         if (ret)
 396                 goto error_kfifo_free;
 397
 398         indio_dev->setup_ops = setup_ops;
 399         indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
 400
 401         return 0;
 402
 403 error_kfifo_free:
 404         iio_kfifo_free(indio_dev->buffer);
 405         return ret;
 406 }
 407
 408 static void tiadc_iio_buffered_hardware_remove(struct iio_dev *indio_dev)
 409 {
 410         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 411
 412         free_irq(adc_dev->mfd_tscadc->irq, indio_dev);
 413         iio_kfifo_free(indio_dev->buffer);
 414 }
 415
 416
 417 static const char * const chan_name_ain[] = {
 418         "AIN0",
 419         "AIN1",
 420         "AIN2",
 421         "AIN3",
 422         "AIN4",
 423         "AIN5",
 424         "AIN6",
 425         "AIN7",
 426 };
 427
 428 static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
 429 {
 430         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 431         struct iio_chan_spec *chan_array;
 432         struct iio_chan_spec *chan;
 433         int i;
 434
 435         indio_dev->num_channels = channels;
 436         chan_array = kcalloc(channels, sizeof(*chan_array), GFP_KERNEL);
 437         if (chan_array == NULL)
 438                 return -ENOMEM;
 439
 440         chan = chan_array;
 441         for (i = 0; i < channels; i++, chan++) {
 442
 443                 chan->type = IIO_VOLTAGE;
 444                 chan->indexed = 1;
 445                 chan->channel = adc_dev->channel_line[i];
 446                 chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 447                 chan->datasheet_name = chan_name_ain[chan->channel];
 448                 chan->scan_index = i;
 449                 chan->scan_type.sign = 'u';
 450                 chan->scan_type.realbits = 12;
 451                 chan->scan_type.storagebits = 16;
 452         }
 453
 454         indio_dev->channels = chan_array;
 455
 456         return 0;
 457 }
 458
 459 static void tiadc_channels_remove(struct iio_dev *indio_dev)
 460 {
 461         kfree(indio_dev->channels);
 462 }
 463
 464 static int tiadc_read_raw(struct iio_dev *indio_dev,
 465                 struct iio_chan_spec const *chan,
 466                 int *val, int *val2, long mask)
 467 {
 468         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 469         int ret = IIO_VAL_INT;
 470         int i, map_val;
 471         unsigned int fifo1count, read, stepid;
 472         bool found = false;
 473         u32 step_en;
 474         unsigned long timeout;
 475
 476         if (iio_buffer_enabled(indio_dev))
 477                 return -EBUSY;
 478
 479         step_en = get_adc_chan_step_mask(adc_dev, chan);
 480         if (!step_en)
 481                 return -EINVAL;
 482
 483         mutex_lock(&adc_dev->fifo1_lock);
 484         fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
 485         while (fifo1count--)
 486                 tiadc_readl(adc_dev, REG_FIFO1);
 487
 488         am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
 489
 490         timeout = jiffies + msecs_to_jiffies
 491                                 (IDLE_TIMEOUT * adc_dev->channels);
 492         /* Wait for Fifo threshold interrupt */
 493         while (1) {
 494                 fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
 495                 if (fifo1count)
 496                         break;
 497
 498                 if (time_after(jiffies, timeout)) {
 499                         am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
 500                         ret = -EAGAIN;
 501                         goto err_unlock;
 502                 }
 503         }
 504         map_val = adc_dev->channel_step[chan->scan_index];
 505
 506         /*
 507          * We check the complete FIFO. We programmed just one entry but in case
 508          * something went wrong we left empty handed (-EAGAIN previously) and
 509          * then the value apeared somehow in the FIFO we would have two entries.
 510          * Therefore we read every item and keep only the latest version of the
 511          * requested channel.
 512          */
 513         for (i = 0; i < fifo1count; i++) {
 514                 read = tiadc_readl(adc_dev, REG_FIFO1);
 515                 stepid = read & FIFOREAD_CHNLID_MASK;
 516                 stepid = stepid >> 0x10;
 517
 518                 if (stepid == map_val) {
 519                         read = read & FIFOREAD_DATA_MASK;
 520                         found = true;
 521                         *val = (u16) read;
 522                 }
 523         }
 524         am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
 525
 526         if (found == false)
 527                 ret =  -EBUSY;
 528
 529 err_unlock:
 530         mutex_unlock(&adc_dev->fifo1_lock);
 531         return ret;
 532 }
 533
 534 static const struct iio_info tiadc_info = {
 535         .read_raw = &tiadc_read_raw,
 536         .driver_module = THIS_MODULE,
 537 };
 538
 539 static int tiadc_request_dma(struct platform_device *pdev,
 540                              struct tiadc_device *adc_dev)
 541 {
 542         struct tiadc_dma        *dma = &adc_dev->dma;
 543         dma_cap_mask_t          mask;
 544
 545         /* Default slave configuration parameters */
 546         dma->conf.direction = DMA_DEV_TO_MEM;
 547         dma->conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 548         dma->conf.src_addr = adc_dev->mfd_tscadc->tscadc_phys_base + REG_FIFO1;
 549
 550         dma_cap_zero(mask);
 551         dma_cap_set(DMA_CYCLIC, mask);
 552
 553         /* Get a channel for RX */
 554         dma->chan = dma_request_chan(adc_dev->mfd_tscadc->dev, "fifo1");
 555         if (IS_ERR(dma->chan)) {
 556                 int ret = PTR_ERR(dma->chan);
 557
 558                 dma->chan = NULL;
 559                 return ret;
 560         }
 561
 562         /* RX buffer */
 563         dma->buf = dma_alloc_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE,
 564                                       &dma->addr, GFP_KERNEL);
 565         if (!dma->buf)
 566                 goto err;
 567
 568         return 0;
 569 err:
 570         dma_release_channel(dma->chan);
 571         return -ENOMEM;
 572 }
 573
 574 static int tiadc_parse_dt(struct platform_device *pdev,
 575                           struct tiadc_device *adc_dev)
 576 {
 577         struct device_node *node = pdev->dev.of_node;
 578         struct property *prop;
 579         const __be32 *cur;
 580         int channels = 0;
 581         u32 val;
 582
 583         of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
 584                 adc_dev->channel_line[channels] = val;
 585
 586                 /* Set Default values for optional DT parameters */
 587                 adc_dev->open_delay[channels] = STEPCONFIG_OPENDLY;
 588                 adc_dev->sample_delay[channels] = STEPCONFIG_SAMPLEDLY;
 589                 adc_dev->step_avg[channels] = 16;
 590
 591                 channels++;
 592         }
 593
 594         of_property_read_u32_array(node, "ti,chan-step-avg",
 595                                    adc_dev->step_avg, channels);
 596         of_property_read_u32_array(node, "ti,chan-step-opendelay",
 597                                    adc_dev->open_delay, channels);
 598         of_property_read_u32_array(node, "ti,chan-step-sampledelay",
 599                                    adc_dev->sample_delay, channels);
 600
 601         adc_dev->channels = channels;
 602         return 0;
 603 }
 604
 605 static int tiadc_probe(struct platform_device *pdev)
 606 {
 607         struct iio_dev          *indio_dev;
 608         struct tiadc_device     *adc_dev;
 609         struct device_node      *node = pdev->dev.of_node;
 610         int                     err;
 611
 612         if (!node) {
 613                 dev_err(&pdev->dev, "Could not find valid DT data.\n");
 614                 return -EINVAL;
 615         }
 616
 617         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
 618         if (indio_dev == NULL) {
 619                 dev_err(&pdev->dev, "failed to allocate iio device\n");
 620                 return -ENOMEM;
 621         }
 622         adc_dev = iio_priv(indio_dev);
 623
 624         adc_dev->mfd_tscadc = ti_tscadc_dev_get(pdev);
 625         tiadc_parse_dt(pdev, adc_dev);
 626
 627         indio_dev->dev.parent = &pdev->dev;
 628         indio_dev->name = dev_name(&pdev->dev);
 629         indio_dev->modes = INDIO_DIRECT_MODE;
 630         indio_dev->info = &tiadc_info;
 631
 632         tiadc_step_config(indio_dev);
 633         tiadc_writel(adc_dev, REG_FIFO1THR, FIFO1_THRESHOLD);
 634         mutex_init(&adc_dev->fifo1_lock);
 635
 636         err = tiadc_channel_init(indio_dev, adc_dev->channels);
 637         if (err < 0)
 638                 return err;
 639
 640         err = tiadc_iio_buffered_hardware_setup(indio_dev,
 641                 &tiadc_worker_h,
 642                 &tiadc_irq_h,
 643                 adc_dev->mfd_tscadc->irq,
 644                 IRQF_SHARED,
 645                 &tiadc_buffer_setup_ops);
 646
 647         if (err)
 648                 goto err_free_channels;
 649
 650         err = iio_device_register(indio_dev);
 651         if (err)
 652                 goto err_buffer_unregister;
 653
 654         platform_set_drvdata(pdev, indio_dev);
 655
 656         err = tiadc_request_dma(pdev, adc_dev);
 657         if (err && err == -EPROBE_DEFER)
 658                 goto err_dma;
 659
 660         return 0;
 661
 662 err_dma:
 663         iio_device_unregister(indio_dev);
 664 err_buffer_unregister:
 665         tiadc_iio_buffered_hardware_remove(indio_dev);
 666 err_free_channels:
 667         tiadc_channels_remove(indio_dev);
 668         return err;
 669 }
 670
 671 static int tiadc_remove(struct platform_device *pdev)
 672 {
 673         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 674         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 675         struct tiadc_dma *dma = &adc_dev->dma;
 676         u32 step_en;
 677
 678         if (dma->chan) {
 679                 dma_free_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE,
 680                                   dma->buf, dma->addr);
 681                 dma_release_channel(dma->chan);
 682         }
 683         iio_device_unregister(indio_dev);
 684         tiadc_iio_buffered_hardware_remove(indio_dev);
 685         tiadc_channels_remove(indio_dev);
 686
 687         step_en = get_adc_step_mask(adc_dev);
 688         am335x_tsc_se_clr(adc_dev->mfd_tscadc, step_en);
 689
 690         return 0;
 691 }
 692
 693 static int __maybe_unused tiadc_suspend(struct device *dev)
 694 {
 695         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 696         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 697         struct ti_tscadc_dev *tscadc_dev;
 698         unsigned int idle;
 699
 700         tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
 701         if (!device_may_wakeup(tscadc_dev->dev)) {
 702                 idle = tiadc_readl(adc_dev, REG_CTRL);
 703                 idle &= ~(CNTRLREG_TSCSSENB);
 704                 tiadc_writel(adc_dev, REG_CTRL, (idle |
 705                                 CNTRLREG_POWERDOWN));
 706         }
 707
 708         return 0;
 709 }
 710
 711 static int __maybe_unused tiadc_resume(struct device *dev)
 712 {
 713         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 714         struct tiadc_device *adc_dev = iio_priv(indio_dev);
 715         unsigned int restore;
 716
 717         /* Make sure ADC is powered up */
 718         restore = tiadc_readl(adc_dev, REG_CTRL);
 719         restore &= ~(CNTRLREG_POWERDOWN);
 720         tiadc_writel(adc_dev, REG_CTRL, restore);
 721
 722         tiadc_step_config(indio_dev);
 723         am335x_tsc_se_set_cache(adc_dev->mfd_tscadc,
 724                         adc_dev->buffer_en_ch_steps);
 725         return 0;
 726 }
 727
 728 static SIMPLE_DEV_PM_OPS(tiadc_pm_ops, tiadc_suspend, tiadc_resume);
 729
 730 static const struct of_device_id ti_adc_dt_ids[] = {
 731         { .compatible = "ti,am3359-adc", },
 732         { }
 733 };
 734 MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
 735
 736 static struct platform_driver tiadc_driver = {
 737         .driver = {
 738                 .name   = "TI-am335x-adc",
 739                 .pm     = &tiadc_pm_ops,
 740                 .of_match_table = ti_adc_dt_ids,
 741         },
 742         .probe  = tiadc_probe,
 743         .remove = tiadc_remove,
 744 };
 745 module_platform_driver(tiadc_driver);
 746
 747 MODULE_DESCRIPTION("TI ADC controller driver");
 748 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
 749 MODULE_LICENSE("GPL");