drivers/iio/adc/mt6360-adc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <linux/bits.h>
   4 #include <linux/delay.h>
   5 #include <linux/irq.h>
   6 #include <linux/kernel.h>
   7 #include <linux/ktime.h>
   8 #include <linux/module.h>
   9 #include <linux/mutex.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/regmap.h>
  12 #include <linux/unaligned/be_byteshift.h>
  13
  14 #include <linux/iio/buffer.h>
  15 #include <linux/iio/iio.h>
  16 #include <linux/iio/trigger_consumer.h>
  17 #include <linux/iio/triggered_buffer.h>
  18
  19 #define MT6360_REG_PMUCHGCTRL3  0x313
  20 #define MT6360_REG_PMUADCCFG    0x356
  21 #define MT6360_REG_PMUADCIDLET  0x358
  22 #define MT6360_REG_PMUADCRPT1   0x35A
  23
  24 /* PMUCHGCTRL3 0x313 */
  25 #define MT6360_AICR_MASK        GENMASK(7, 2)
  26 #define MT6360_AICR_SHFT        2
  27 #define MT6360_AICR_400MA       0x6
  28 /* PMUADCCFG 0x356 */
  29 #define MT6360_ADCEN_MASK       BIT(15)
  30 /* PMUADCRPT1 0x35A */
  31 #define MT6360_PREFERCH_MASK    GENMASK(7, 4)
  32 #define MT6360_PREFERCH_SHFT    4
  33 #define MT6360_RPTCH_MASK       GENMASK(3, 0)
  34 #define MT6360_NO_PREFER        15
  35
  36 /* Time in ms */
  37 #define ADC_WAIT_TIME_MS        25
  38 #define ADC_CONV_TIMEOUT_MS     100
  39 #define ADC_LOOP_TIME_US        2000
  40
  41 enum {
  42         MT6360_CHAN_USBID = 0,
  43         MT6360_CHAN_VBUSDIV5,
  44         MT6360_CHAN_VBUSDIV2,
  45         MT6360_CHAN_VSYS,
  46         MT6360_CHAN_VBAT,
  47         MT6360_CHAN_IBUS,
  48         MT6360_CHAN_IBAT,
  49         MT6360_CHAN_CHG_VDDP,
  50         MT6360_CHAN_TEMP_JC,
  51         MT6360_CHAN_VREF_TS,
  52         MT6360_CHAN_TS,
  53         MT6360_CHAN_MAX
  54 };
  55
  56 struct mt6360_adc_data {
  57         struct device *dev;
  58         struct regmap *regmap;
  59         /* Due to only one set of ADC control, this lock is used to prevent the race condition */
  60         struct mutex adc_lock;
  61         ktime_t last_off_timestamps[MT6360_CHAN_MAX];
  62 };
  63
  64 static int mt6360_adc_read_channel(struct mt6360_adc_data *mad, int channel, int *val)
  65 {
  66         __be16 adc_enable;
  67         u8 rpt[3];
  68         ktime_t predict_end_t, timeout;
  69         unsigned int pre_wait_time;
  70         int ret;
  71
  72         mutex_lock(&mad->adc_lock);
  73
  74         /* Select the preferred ADC channel */
  75         ret = regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK,
  76                                  channel << MT6360_PREFERCH_SHFT);
  77         if (ret)
  78                 goto out_adc_lock;
  79
  80         adc_enable = cpu_to_be16(MT6360_ADCEN_MASK | BIT(channel));
  81         ret = regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
  82         if (ret)
  83                 goto out_adc_lock;
  84
  85         predict_end_t = ktime_add_ms(mad->last_off_timestamps[channel], 2 * ADC_WAIT_TIME_MS);
  86
  87         if (ktime_after(ktime_get(), predict_end_t))
  88                 pre_wait_time = ADC_WAIT_TIME_MS;
  89         else
  90                 pre_wait_time = 3 * ADC_WAIT_TIME_MS;
  91
  92         if (msleep_interruptible(pre_wait_time)) {
  93                 ret = -ERESTARTSYS;
  94                 goto out_adc_conv;
  95         }
  96
  97         timeout = ktime_add_ms(ktime_get(), ADC_CONV_TIMEOUT_MS);
  98         while (true) {
  99                 ret = regmap_raw_read(mad->regmap, MT6360_REG_PMUADCRPT1, rpt, sizeof(rpt));
 100                 if (ret)
 101                         goto out_adc_conv;
 102
 103                 /*
 104                  * There are two functions, ZCV and TypeC OTP, running ADC VBAT and TS in
 105                  * background, and ADC samples are taken on a fixed frequency no matter read the
 106                  * previous one or not.
 107                  * To avoid conflict, We set minimum time threshold after enable ADC and
 108                  * check report channel is the same.
 109                  * The worst case is run the same ADC twice and background function is also running,
 110                  * ADC conversion sequence is desire channel before start ADC, background ADC,
 111                  * desire channel after start ADC.
 112                  * So the minimum correct data is three times of typical conversion time.
 113                  */
 114                 if ((rpt[0] & MT6360_RPTCH_MASK) == channel)
 115                         break;
 116
 117                 if (ktime_compare(ktime_get(), timeout) > 0) {
 118                         ret = -ETIMEDOUT;
 119                         goto out_adc_conv;
 120                 }
 121
 122                 usleep_range(ADC_LOOP_TIME_US / 2, ADC_LOOP_TIME_US);
 123         }
 124
 125         *val = rpt[1] << 8 | rpt[2];
 126         ret = IIO_VAL_INT;
 127
 128 out_adc_conv:
 129         /* Only keep ADC enable */
 130         adc_enable = cpu_to_be16(MT6360_ADCEN_MASK);
 131         regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
 132         mad->last_off_timestamps[channel] = ktime_get();
 133         /* Config prefer channel to NO_PREFER */
 134         regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK,
 135                            MT6360_NO_PREFER << MT6360_PREFERCH_SHFT);
 136 out_adc_lock:
 137         mutex_unlock(&mad->adc_lock);
 138
 139         return ret;
 140 }
 141
 142 static int mt6360_adc_read_scale(struct mt6360_adc_data *mad, int channel, int *val, int *val2)
 143 {
 144         unsigned int regval;
 145         int ret;
 146
 147         switch (channel) {
 148         case MT6360_CHAN_USBID:
 149         case MT6360_CHAN_VSYS:
 150         case MT6360_CHAN_VBAT:
 151         case MT6360_CHAN_CHG_VDDP:
 152         case MT6360_CHAN_VREF_TS:
 153         case MT6360_CHAN_TS:
 154                 *val = 1250;
 155                 return IIO_VAL_INT;
 156         case MT6360_CHAN_VBUSDIV5:
 157                 *val = 6250;
 158                 return IIO_VAL_INT;
 159         case MT6360_CHAN_VBUSDIV2:
 160         case MT6360_CHAN_IBUS:
 161         case MT6360_CHAN_IBAT:
 162                 *val = 2500;
 163
 164                 if (channel == MT6360_CHAN_IBUS) {
 165                         /* IBUS will be affected by input current limit for the different Ron */
 166                         /* Check whether the config is <400mA or not */
 167                         ret = regmap_read(mad->regmap, MT6360_REG_PMUCHGCTRL3, &regval);
 168                         if (ret)
 169                                 return ret;
 170
 171                         regval = (regval & MT6360_AICR_MASK) >> MT6360_AICR_SHFT;
 172                         if (regval < MT6360_AICR_400MA)
 173                                 *val = 1900;
 174                 }
 175
 176                 return IIO_VAL_INT;
 177         case MT6360_CHAN_TEMP_JC:
 178                 *val = 105;
 179                 *val2 = 100;
 180                 return IIO_VAL_FRACTIONAL;
 181         }
 182
 183         return -EINVAL;
 184 }
 185
 186 static int mt6360_adc_read_offset(struct mt6360_adc_data *mad, int channel, int *val)
 187 {
 188         *val = (channel == MT6360_CHAN_TEMP_JC) ? -80 : 0;
 189         return IIO_VAL_INT;
 190 }
 191
 192 static int mt6360_adc_read_raw(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
 193                                int *val, int *val2, long mask)
 194 {
 195         struct mt6360_adc_data *mad = iio_priv(iio_dev);
 196
 197         switch (mask) {
 198         case IIO_CHAN_INFO_RAW:
 199                 return mt6360_adc_read_channel(mad, chan->channel, val);
 200         case IIO_CHAN_INFO_SCALE:
 201                 return mt6360_adc_read_scale(mad, chan->channel, val, val2);
 202         case IIO_CHAN_INFO_OFFSET:
 203                 return mt6360_adc_read_offset(mad, chan->channel, val);
 204         }
 205
 206         return -EINVAL;
 207 }
 208
 209 static const char *mt6360_channel_labels[MT6360_CHAN_MAX] = {
 210         "usbid", "vbusdiv5", "vbusdiv2", "vsys", "vbat", "ibus", "ibat", "chg_vddp",
 211         "temp_jc", "vref_ts", "ts",
 212 };
 213
 214 static int mt6360_adc_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
 215                                  char *label)
 216 {
 217         return snprintf(label, PAGE_SIZE, "%s\n", mt6360_channel_labels[chan->channel]);
 218 }
 219
 220 static const struct iio_info mt6360_adc_iio_info = {
 221         .read_raw = mt6360_adc_read_raw,
 222         .read_label = mt6360_adc_read_label,
 223 };
 224
 225 #define MT6360_ADC_CHAN(_idx, _type) {                          \
 226         .type = _type,                                          \
 227         .channel = MT6360_CHAN_##_idx,                          \
 228         .scan_index = MT6360_CHAN_##_idx,                       \
 229         .datasheet_name = #_idx,                                \
 230         .scan_type =  {                                         \
 231                 .sign = 'u',                                    \
 232                 .realbits = 16,                                 \
 233                 .storagebits = 16,                              \
 234                 .endianness = IIO_CPU,                          \
 235         },                                                      \
 236         .indexed = 1,                                           \
 237         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |          \
 238                                 BIT(IIO_CHAN_INFO_SCALE) |      \
 239                                 BIT(IIO_CHAN_INFO_OFFSET),      \
 240 }
 241
 242 static const struct iio_chan_spec mt6360_adc_channels[] = {
 243         MT6360_ADC_CHAN(USBID, IIO_VOLTAGE),
 244         MT6360_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE),
 245         MT6360_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE),
 246         MT6360_ADC_CHAN(VSYS, IIO_VOLTAGE),
 247         MT6360_ADC_CHAN(VBAT, IIO_VOLTAGE),
 248         MT6360_ADC_CHAN(IBUS, IIO_CURRENT),
 249         MT6360_ADC_CHAN(IBAT, IIO_CURRENT),
 250         MT6360_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE),
 251         MT6360_ADC_CHAN(TEMP_JC, IIO_TEMP),
 252         MT6360_ADC_CHAN(VREF_TS, IIO_VOLTAGE),
 253         MT6360_ADC_CHAN(TS, IIO_VOLTAGE),
 254         IIO_CHAN_SOFT_TIMESTAMP(MT6360_CHAN_MAX),
 255 };
 256
 257 static irqreturn_t mt6360_adc_trigger_handler(int irq, void *p)
 258 {
 259         struct iio_poll_func *pf = p;
 260         struct iio_dev *indio_dev = pf->indio_dev;
 261         struct mt6360_adc_data *mad = iio_priv(indio_dev);
 262         struct {
 263                 u16 values[MT6360_CHAN_MAX];
 264                 int64_t timestamp;
 265         } data __aligned(8);
 266         int i = 0, bit, val, ret;
 267
 268         memset(&data, 0, sizeof(data));
 269         for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) {
 270                 ret = mt6360_adc_read_channel(mad, bit, &val);
 271                 if (ret < 0) {
 272                         dev_warn(&indio_dev->dev, "Failed to get channel %d conversion val\n", bit);
 273                         goto out;
 274                 }
 275
 276                 data.values[i++] = val;
 277         }
 278         iio_push_to_buffers_with_timestamp(indio_dev, &data, iio_get_time_ns(indio_dev));
 279 out:
 280         iio_trigger_notify_done(indio_dev->trig);
 281
 282         return IRQ_HANDLED;
 283 }
 284
 285 static inline int mt6360_adc_reset(struct mt6360_adc_data *info)
 286 {
 287         __be16 adc_enable;
 288         ktime_t all_off_time;
 289         int i, ret;
 290
 291         /* Clear ADC idle wait time to 0 */
 292         ret = regmap_write(info->regmap, MT6360_REG_PMUADCIDLET, 0);
 293         if (ret)
 294                 return ret;
 295
 296         /* Only keep ADC enable, but keep all channels off */
 297         adc_enable = cpu_to_be16(MT6360_ADCEN_MASK);
 298         ret = regmap_raw_write(info->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
 299         if (ret)
 300                 return ret;
 301
 302         /* Reset all channel off time to the current one */
 303         all_off_time = ktime_get();
 304         for (i = 0; i < MT6360_CHAN_MAX; i++)
 305                 info->last_off_timestamps[i] = all_off_time;
 306
 307         return 0;
 308 }
 309
 310 static int mt6360_adc_probe(struct platform_device *pdev)
 311 {
 312         struct mt6360_adc_data *mad;
 313         struct regmap *regmap;
 314         struct iio_dev *indio_dev;
 315         int ret;
 316
 317         regmap = dev_get_regmap(pdev->dev.parent, NULL);
 318         if (!regmap) {
 319                 dev_err(&pdev->dev, "Failed to get parent regmap\n");
 320                 return -ENODEV;
 321         }
 322
 323         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*mad));
 324         if (!indio_dev)
 325                 return -ENOMEM;
 326
 327         mad = iio_priv(indio_dev);
 328         mad->dev = &pdev->dev;
 329         mad->regmap = regmap;
 330         mutex_init(&mad->adc_lock);
 331
 332         ret = mt6360_adc_reset(mad);
 333         if (ret < 0) {
 334                 dev_err(&pdev->dev, "Failed to reset adc\n");
 335                 return ret;
 336         }
 337
 338         indio_dev->name = dev_name(&pdev->dev);
 339         indio_dev->dev.parent = &pdev->dev;
 340         indio_dev->info = &mt6360_adc_iio_info;
 341         indio_dev->modes = INDIO_DIRECT_MODE;
 342         indio_dev->channels = mt6360_adc_channels;
 343         indio_dev->num_channels = ARRAY_SIZE(mt6360_adc_channels);
 344
 345         ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, NULL,
 346                                               mt6360_adc_trigger_handler, NULL);
 347         if (ret) {
 348                 dev_err(&pdev->dev, "Failed to allocate iio trigger buffer\n");
 349                 return ret;
 350         }
 351
 352         return devm_iio_device_register(&pdev->dev, indio_dev);
 353 }
 354
 355 static const struct of_device_id __maybe_unused mt6360_adc_of_id[] = {
 356         { .compatible = "mediatek,mt6360-adc", },
 357         {}
 358 };
 359 MODULE_DEVICE_TABLE(of, mt6360_adc_of_id);
 360
 361 static struct platform_driver mt6360_adc_driver = {
 362         .driver = {
 363                 .name = "mt6360-adc",
 364                 .of_match_table = mt6360_adc_of_id,
 365         },
 366         .probe = mt6360_adc_probe,
 367 };
 368 module_platform_driver(mt6360_adc_driver);
 369
 370 MODULE_AUTHOR("Gene Chen <gene_chen@richtek.com>");
 371 MODULE_DESCRIPTION("MT6360 ADC Driver");
 372 MODULE_LICENSE("GPL v2");