drivers/iio/adc/berlin2-adc.c

   1 /*
   2  * Marvell Berlin2 ADC driver
   3  *
   4  * Copyright (C) 2015 Marvell Technology Group Ltd.
   5  *
   6  * Antoine Tenart <antoine.tenart@free-electrons.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2. This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  */
  12
  13 #include <linux/iio/iio.h>
  14 #include <linux/iio/driver.h>
  15 #include <linux/iio/machine.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/slab.h>
  21 #include <linux/mfd/syscon.h>
  22 #include <linux/regmap.h>
  23 #include <linux/sched.h>
  24 #include <linux/wait.h>
  25
  26 #define BERLIN2_SM_CTRL                         0x14
  27 #define  BERLIN2_SM_CTRL_SM_SOC_INT             BIT(1)
  28 #define  BERLIN2_SM_CTRL_SOC_SM_INT             BIT(2)
  29 #define  BERLIN2_SM_CTRL_ADC_SEL(x)             ((x) << 5)      /* 0-15 */
  30 #define  BERLIN2_SM_CTRL_ADC_SEL_MASK           GENMASK(8, 5)
  31 #define  BERLIN2_SM_CTRL_ADC_POWER              BIT(9)
  32 #define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2        (0x0 << 10)
  33 #define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3        (0x1 << 10)
  34 #define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4        (0x2 << 10)
  35 #define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8        (0x3 << 10)
  36 #define  BERLIN2_SM_CTRL_ADC_CLKSEL_MASK        GENMASK(11, 10)
  37 #define  BERLIN2_SM_CTRL_ADC_START              BIT(12)
  38 #define  BERLIN2_SM_CTRL_ADC_RESET              BIT(13)
  39 #define  BERLIN2_SM_CTRL_ADC_BANDGAP_RDY        BIT(14)
  40 #define  BERLIN2_SM_CTRL_ADC_CONT_SINGLE        (0x0 << 15)
  41 #define  BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS    (0x1 << 15)
  42 #define  BERLIN2_SM_CTRL_ADC_BUFFER_EN          BIT(16)
  43 #define  BERLIN2_SM_CTRL_ADC_VREF_EXT           (0x0 << 17)
  44 #define  BERLIN2_SM_CTRL_ADC_VREF_INT           (0x1 << 17)
  45 #define  BERLIN2_SM_CTRL_ADC_ROTATE             BIT(19)
  46 #define  BERLIN2_SM_CTRL_TSEN_EN                BIT(20)
  47 #define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_125       (0x0 << 21)     /* 1.25 MHz */
  48 #define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_250       (0x1 << 21)     /* 2.5 MHz */
  49 #define  BERLIN2_SM_CTRL_TSEN_MODE_0_125        (0x0 << 22)     /* 0-125 C */
  50 #define  BERLIN2_SM_CTRL_TSEN_MODE_10_50        (0x1 << 22)     /* 10-50 C */
  51 #define  BERLIN2_SM_CTRL_TSEN_RESET             BIT(29)
  52 #define BERLIN2_SM_ADC_DATA                     0x20
  53 #define  BERLIN2_SM_ADC_MASK                    GENMASK(9, 0)
  54 #define BERLIN2_SM_ADC_STATUS                   0x1c
  55 #define  BERLIN2_SM_ADC_STATUS_DATA_RDY(x)      BIT(x)          /* 0-15 */
  56 #define  BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK    GENMASK(15, 0)
  57 #define  BERLIN2_SM_ADC_STATUS_INT_EN(x)        (BIT(x) << 16)  /* 0-15 */
  58 #define  BERLIN2_SM_ADC_STATUS_INT_EN_MASK      GENMASK(31, 16)
  59 #define BERLIN2_SM_TSEN_STATUS                  0x24
  60 #define  BERLIN2_SM_TSEN_STATUS_DATA_RDY        BIT(0)
  61 #define  BERLIN2_SM_TSEN_STATUS_INT_EN          BIT(1)
  62 #define BERLIN2_SM_TSEN_DATA                    0x28
  63 #define  BERLIN2_SM_TSEN_MASK                   GENMASK(9, 0)
  64 #define BERLIN2_SM_TSEN_CTRL                    0x74
  65 #define  BERLIN2_SM_TSEN_CTRL_START             BIT(8)
  66 #define  BERLIN2_SM_TSEN_CTRL_SETTLING_4        (0x0 << 21)     /* 4 us */
  67 #define  BERLIN2_SM_TSEN_CTRL_SETTLING_12       (0x1 << 21)     /* 12 us */
  68 #define  BERLIN2_SM_TSEN_CTRL_SETTLING_MASK     BIT(21)
  69 #define  BERLIN2_SM_TSEN_CTRL_TRIM(x)           ((x) << 22)
  70 #define  BERLIN2_SM_TSEN_CTRL_TRIM_MASK         GENMASK(25, 22)
  71
  72 struct berlin2_adc_priv {
  73         struct regmap           *regmap;
  74         struct mutex            lock;
  75         wait_queue_head_t       wq;
  76         bool                    data_available;
  77         int                     data;
  78 };
  79
  80 #define BERLIN2_ADC_CHANNEL(n, t)                                       \
  81         {                                                               \
  82                 .channel                = n,                            \
  83                 .datasheet_name         = "channel"#n,                  \
  84                 .type                   = t,                            \
  85                 .indexed                = 1,                            \
  86                 .info_mask_separate     = BIT(IIO_CHAN_INFO_RAW),       \
  87         }
  88
  89 static const struct iio_chan_spec berlin2_adc_channels[] = {
  90         BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE),    /* external input */
  91         BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE),    /* external input */
  92         BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE),    /* external input */
  93         BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE),    /* external input */
  94         BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE),    /* reserved */
  95         BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE),    /* reserved */
  96         {                                       /* temperature sensor */
  97                 .channel                = 6,
  98                 .datasheet_name         = "channel6",
  99                 .type                   = IIO_TEMP,
 100                 .indexed                = 0,
 101                 .info_mask_separate     = BIT(IIO_CHAN_INFO_PROCESSED),
 102         },
 103         BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE),    /* reserved */
 104         IIO_CHAN_SOFT_TIMESTAMP(8),             /* timestamp */
 105 };
 106
 107 static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
 108 {
 109         struct berlin2_adc_priv *priv = iio_priv(indio_dev);
 110         int data, ret;
 111
 112         mutex_lock(&priv->lock);
 113
 114         /* Enable the interrupts */
 115         regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
 116                      BERLIN2_SM_ADC_STATUS_INT_EN(channel));
 117
 118         /* Configure the ADC */
 119         regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
 120                            BERLIN2_SM_CTRL_ADC_RESET |
 121                            BERLIN2_SM_CTRL_ADC_SEL_MASK |
 122                            BERLIN2_SM_CTRL_ADC_START,
 123                            BERLIN2_SM_CTRL_ADC_SEL(channel) |
 124                            BERLIN2_SM_CTRL_ADC_START);
 125
 126         ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
 127                                                msecs_to_jiffies(1000));
 128
 129         /* Disable the interrupts */
 130         regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
 131                            BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
 132
 133         if (ret == 0)
 134                 ret = -ETIMEDOUT;
 135         if (ret < 0) {
 136                 mutex_unlock(&priv->lock);
 137                 return ret;
 138         }
 139
 140         regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
 141                            BERLIN2_SM_CTRL_ADC_START, 0);
 142
 143         data = priv->data;
 144         priv->data_available = false;
 145
 146         mutex_unlock(&priv->lock);
 147
 148         return data;
 149 }
 150
 151 static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
 152 {
 153         struct berlin2_adc_priv *priv = iio_priv(indio_dev);
 154         int data, ret;
 155
 156         mutex_lock(&priv->lock);
 157
 158         /* Enable interrupts */
 159         regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
 160                      BERLIN2_SM_TSEN_STATUS_INT_EN);
 161
 162         /* Configure the ADC */
 163         regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
 164                            BERLIN2_SM_CTRL_TSEN_RESET |
 165                            BERLIN2_SM_CTRL_ADC_ROTATE,
 166                            BERLIN2_SM_CTRL_ADC_ROTATE);
 167
 168         /* Configure the temperature sensor */
 169         regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
 170                            BERLIN2_SM_TSEN_CTRL_TRIM_MASK |
 171                            BERLIN2_SM_TSEN_CTRL_SETTLING_MASK |
 172                            BERLIN2_SM_TSEN_CTRL_START,
 173                            BERLIN2_SM_TSEN_CTRL_TRIM(3) |
 174                            BERLIN2_SM_TSEN_CTRL_SETTLING_12 |
 175                            BERLIN2_SM_TSEN_CTRL_START);
 176
 177         ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
 178                                                msecs_to_jiffies(1000));
 179
 180         /* Disable interrupts */
 181         regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
 182                            BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
 183
 184         if (ret == 0)
 185                 ret = -ETIMEDOUT;
 186         if (ret < 0) {
 187                 mutex_unlock(&priv->lock);
 188                 return ret;
 189         }
 190
 191         regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
 192                            BERLIN2_SM_TSEN_CTRL_START, 0);
 193
 194         data = priv->data;
 195         priv->data_available = false;
 196
 197         mutex_unlock(&priv->lock);
 198
 199         return data;
 200 }
 201
 202 static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
 203                                 struct iio_chan_spec const *chan, int *val,
 204                                 int *val2, long mask)
 205 {
 206         int temp;
 207
 208         switch (mask) {
 209         case IIO_CHAN_INFO_RAW:
 210                 if (chan->type != IIO_VOLTAGE)
 211                         return -EINVAL;
 212
 213                 *val = berlin2_adc_read(indio_dev, chan->channel);
 214                 if (*val < 0)
 215                         return *val;
 216
 217                 return IIO_VAL_INT;
 218         case IIO_CHAN_INFO_PROCESSED:
 219                 if (chan->type != IIO_TEMP)
 220                         return -EINVAL;
 221
 222                 temp = berlin2_adc_tsen_read(indio_dev);
 223                 if (temp < 0)
 224                         return temp;
 225
 226                 if (temp > 2047)
 227                         temp -= 4096;
 228
 229                 /* Convert to milli Celsius */
 230                 *val = ((temp * 100000) / 264 - 270000);
 231                 return IIO_VAL_INT;
 232         default:
 233                 break;
 234         }
 235
 236         return -EINVAL;
 237 }
 238
 239 static irqreturn_t berlin2_adc_irq(int irq, void *private)
 240 {
 241         struct berlin2_adc_priv *priv = iio_priv(private);
 242         unsigned val;
 243
 244         regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
 245         if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
 246                 regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
 247                 priv->data &= BERLIN2_SM_ADC_MASK;
 248
 249                 val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
 250                 regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
 251
 252                 priv->data_available = true;
 253                 wake_up_interruptible(&priv->wq);
 254         }
 255
 256         return IRQ_HANDLED;
 257 }
 258
 259 static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
 260 {
 261         struct berlin2_adc_priv *priv = iio_priv(private);
 262         unsigned val;
 263
 264         regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
 265         if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
 266                 regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
 267                 priv->data &= BERLIN2_SM_TSEN_MASK;
 268
 269                 val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
 270                 regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
 271
 272                 priv->data_available = true;
 273                 wake_up_interruptible(&priv->wq);
 274         }
 275
 276         return IRQ_HANDLED;
 277 }
 278
 279 static const struct iio_info berlin2_adc_info = {
 280         .read_raw       = berlin2_adc_read_raw,
 281 };
 282
 283 static int berlin2_adc_probe(struct platform_device *pdev)
 284 {
 285         struct iio_dev *indio_dev;
 286         struct berlin2_adc_priv *priv;
 287         struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
 288         int irq, tsen_irq;
 289         int ret;
 290
 291         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
 292         if (!indio_dev)
 293                 return -ENOMEM;
 294
 295         priv = iio_priv(indio_dev);
 296         platform_set_drvdata(pdev, indio_dev);
 297
 298         priv->regmap = syscon_node_to_regmap(parent_np);
 299         of_node_put(parent_np);
 300         if (IS_ERR(priv->regmap))
 301                 return PTR_ERR(priv->regmap);
 302
 303         irq = platform_get_irq_byname(pdev, "adc");
 304         if (irq < 0)
 305                 return irq;
 306
 307         tsen_irq = platform_get_irq_byname(pdev, "tsen");
 308         if (tsen_irq < 0)
 309                 return tsen_irq;
 310
 311         ret = devm_request_irq(&pdev->dev, irq, berlin2_adc_irq, 0,
 312                                pdev->dev.driver->name, indio_dev);
 313         if (ret)
 314                 return ret;
 315
 316         ret = devm_request_irq(&pdev->dev, tsen_irq, berlin2_adc_tsen_irq,
 317                                0, pdev->dev.driver->name, indio_dev);
 318         if (ret)
 319                 return ret;
 320
 321         init_waitqueue_head(&priv->wq);
 322         mutex_init(&priv->lock);
 323
 324         indio_dev->dev.parent = &pdev->dev;
 325         indio_dev->name = dev_name(&pdev->dev);
 326         indio_dev->modes = INDIO_DIRECT_MODE;
 327         indio_dev->info = &berlin2_adc_info;
 328
 329         indio_dev->channels = berlin2_adc_channels;
 330         indio_dev->num_channels = ARRAY_SIZE(berlin2_adc_channels);
 331
 332         /* Power up the ADC */
 333         regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
 334                            BERLIN2_SM_CTRL_ADC_POWER,
 335                            BERLIN2_SM_CTRL_ADC_POWER);
 336
 337         ret = iio_device_register(indio_dev);
 338         if (ret) {
 339                 /* Power down the ADC */
 340                 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
 341                                    BERLIN2_SM_CTRL_ADC_POWER, 0);
 342                 return ret;
 343         }
 344
 345         return 0;
 346 }
 347
 348 static int berlin2_adc_remove(struct platform_device *pdev)
 349 {
 350         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 351         struct berlin2_adc_priv *priv = iio_priv(indio_dev);
 352
 353         iio_device_unregister(indio_dev);
 354
 355         /* Power down the ADC */
 356         regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
 357                            BERLIN2_SM_CTRL_ADC_POWER, 0);
 358
 359         return 0;
 360 }
 361
 362 static const struct of_device_id berlin2_adc_match[] = {
 363         { .compatible = "marvell,berlin2-adc", },
 364         { },
 365 };
 366 MODULE_DEVICE_TABLE(of, berlin2_adc_match);
 367
 368 static struct platform_driver berlin2_adc_driver = {
 369         .driver = {
 370                 .name           = "berlin2-adc",
 371                 .of_match_table = berlin2_adc_match,
 372         },
 373         .probe  = berlin2_adc_probe,
 374         .remove = berlin2_adc_remove,
 375 };
 376 module_platform_driver(berlin2_adc_driver);
 377
 378 MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
 379 MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
 380 MODULE_LICENSE("GPL v2");