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/mod_devicetable.h>
   9 #include <linux/module.h>
  10 #include <linux/mutex.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/regmap.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 #include <linux/unaligned.h>
  20
  21 #define MT6360_REG_PMUCHGCTRL3  0x313
  22 #define MT6360_REG_PMUADCCFG    0x356
  23 #define MT6360_REG_PMUADCIDLET  0x358
  24 #define MT6360_REG_PMUADCRPT1   0x35A
  25
  26 /* PMUCHGCTRL3 0x313 */
  27 #define MT6360_AICR_MASK        GENMASK(7, 2)
  28 #define MT6360_AICR_SHFT        2
  29 #define MT6360_AICR_400MA       0x6
  30 /* PMUADCCFG 0x356 */
  31 #define MT6360_ADCEN_MASK       BIT(15)
  32 /* PMUADCRPT1 0x35A */
  33 #define MT6360_PREFERCH_MASK    GENMASK(7, 4)
  34 #define MT6360_PREFERCH_SHFT    4
  35 #define MT6360_RPTCH_MASK       GENMASK(3, 0)
  36 #define MT6360_NO_PREFER        15
  37
  38 /* Time in ms */
  39 #define ADC_WAIT_TIME_MS        25
  40 #define ADC_CONV_TIMEOUT_MS     100
  41 #define ADC_LOOP_TIME_US        2000
  42
  43 enum {
  44         MT6360_CHAN_USBID = 0,
  45         MT6360_CHAN_VBUSDIV5,
  46         MT6360_CHAN_VBUSDIV2,
  47         MT6360_CHAN_VSYS,
  48         MT6360_CHAN_VBAT,
  49         MT6360_CHAN_IBUS,
  50         MT6360_CHAN_IBAT,
  51         MT6360_CHAN_CHG_VDDP,
  52         MT6360_CHAN_TEMP_JC,
  53         MT6360_CHAN_VREF_TS,
  54         MT6360_CHAN_TS,
  55         MT6360_CHAN_MAX
  56 };
  57
  58 struct mt6360_adc_data {
  59         struct device *dev;
  60         struct regmap *regmap;
  61         /* Due to only one set of ADC control, this lock is used to prevent the race condition */
  62         struct mutex adc_lock;
  63         ktime_t last_off_timestamps[MT6360_CHAN_MAX];
  64 };
  65
  66 static int mt6360_adc_read_channel(struct mt6360_adc_data *mad, int channel, int *val)
  67 {
  68         __be16 adc_enable;
  69         u8 rpt[3];
  70         ktime_t predict_end_t, timeout;
  71         unsigned int pre_wait_time;
  72         int ret;
  73
  74         mutex_lock(&mad->adc_lock);
  75
  76         /* Select the preferred ADC channel */
  77         ret = regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK,
  78                                  channel << MT6360_PREFERCH_SHFT);
  79         if (ret)
  80                 goto out_adc_lock;
  81
  82         adc_enable = cpu_to_be16(MT6360_ADCEN_MASK | BIT(channel));
  83         ret = regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
  84         if (ret)
  85                 goto out_adc_lock;
  86
  87         predict_end_t = ktime_add_ms(mad->last_off_timestamps[channel], 2 * ADC_WAIT_TIME_MS);
  88
  89         if (ktime_after(ktime_get(), predict_end_t))
  90                 pre_wait_time = ADC_WAIT_TIME_MS;
  91         else
  92                 pre_wait_time = 3 * ADC_WAIT_TIME_MS;
  93
  94         if (msleep_interruptible(pre_wait_time)) {
  95                 ret = -ERESTARTSYS;
  96                 goto out_adc_conv;
  97         }
  98
  99         timeout = ktime_add_ms(ktime_get(), ADC_CONV_TIMEOUT_MS);
 100         while (true) {
 101                 ret = regmap_raw_read(mad->regmap, MT6360_REG_PMUADCRPT1, rpt, sizeof(rpt));
 102                 if (ret)
 103                         goto out_adc_conv;
 104
 105                 /*
 106                  * There are two functions, ZCV and TypeC OTP, running ADC VBAT and TS in
 107                  * background, and ADC samples are taken on a fixed frequency no matter read the
 108                  * previous one or not.
 109                  * To avoid conflict, We set minimum time threshold after enable ADC and
 110                  * check report channel is the same.
 111                  * The worst case is run the same ADC twice and background function is also running,
 112                  * ADC conversion sequence is desire channel before start ADC, background ADC,
 113                  * desire channel after start ADC.
 114                  * So the minimum correct data is three times of typical conversion time.
 115                  */
 116                 if ((rpt[0] & MT6360_RPTCH_MASK) == channel)
 117                         break;
 118
 119                 if (ktime_compare(ktime_get(), timeout) > 0) {
 120                         ret = -ETIMEDOUT;
 121                         goto out_adc_conv;
 122                 }
 123
 124                 usleep_range(ADC_LOOP_TIME_US / 2, ADC_LOOP_TIME_US);
 125         }
 126
 127         *val = get_unaligned_be16(&rpt[1]);
 128         ret = IIO_VAL_INT;
 129
 130 out_adc_conv:
 131         /* Only keep ADC enable */
 132         adc_enable = cpu_to_be16(MT6360_ADCEN_MASK);
 133         regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
 134         mad->last_off_timestamps[channel] = ktime_get();
 135         /* Config prefer channel to NO_PREFER */
 136         regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK,
 137                            MT6360_NO_PREFER << MT6360_PREFERCH_SHFT);
 138 out_adc_lock:
 139         mutex_unlock(&mad->adc_lock);
 140
 141         return ret;
 142 }
 143
 144 static int mt6360_adc_read_scale(struct mt6360_adc_data *mad, int channel, int *val, int *val2)
 145 {
 146         unsigned int regval;
 147         int ret;
 148
 149         switch (channel) {
 150         case MT6360_CHAN_USBID:
 151         case MT6360_CHAN_VSYS:
 152         case MT6360_CHAN_VBAT:
 153         case MT6360_CHAN_CHG_VDDP:
 154         case MT6360_CHAN_VREF_TS:
 155         case MT6360_CHAN_TS:
 156                 *val = 1250;
 157                 return IIO_VAL_INT;
 158         case MT6360_CHAN_VBUSDIV5:
 159                 *val = 6250;
 160                 return IIO_VAL_INT;
 161         case MT6360_CHAN_VBUSDIV2:
 162         case MT6360_CHAN_IBUS:
 163         case MT6360_CHAN_IBAT:
 164                 *val = 2500;
 165
 166                 if (channel == MT6360_CHAN_IBUS) {
 167                         /* IBUS will be affected by input current limit for the different Ron */
 168                         /* Check whether the config is <400mA or not */
 169                         ret = regmap_read(mad->regmap, MT6360_REG_PMUCHGCTRL3, &regval);
 170                         if (ret)
 171                                 return ret;
 172
 173                         regval = (regval & MT6360_AICR_MASK) >> MT6360_AICR_SHFT;
 174                         if (regval < MT6360_AICR_400MA)
 175                                 *val = 1900;
 176                 }
 177
 178                 return IIO_VAL_INT;
 179         case MT6360_CHAN_TEMP_JC:
 180                 *val = 105;
 181                 *val2 = 100;
 182                 return IIO_VAL_FRACTIONAL;
 183         }
 184
 185         return -EINVAL;
 186 }
 187
 188 static int mt6360_adc_read_offset(struct mt6360_adc_data *mad, int channel, int *val)
 189 {
 190         *val = (channel == MT6360_CHAN_TEMP_JC) ? -80 : 0;
 191         return IIO_VAL_INT;
 192 }
 193
 194 static int mt6360_adc_read_raw(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
 195                                int *val, int *val2, long mask)
 196 {
 197         struct mt6360_adc_data *mad = iio_priv(iio_dev);
 198
 199         switch (mask) {
 200         case IIO_CHAN_INFO_RAW:
 201                 return mt6360_adc_read_channel(mad, chan->channel, val);
 202         case IIO_CHAN_INFO_SCALE:
 203                 return mt6360_adc_read_scale(mad, chan->channel, val, val2);
 204         case IIO_CHAN_INFO_OFFSET:
 205                 return mt6360_adc_read_offset(mad, chan->channel, val);
 206         }
 207
 208         return -EINVAL;
 209 }
 210
 211 static const char *mt6360_channel_labels[MT6360_CHAN_MAX] = {
 212         "usbid", "vbusdiv5", "vbusdiv2", "vsys", "vbat", "ibus", "ibat", "chg_vddp",
 213         "temp_jc", "vref_ts", "ts",
 214 };
 215
 216 static int mt6360_adc_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
 217                                  char *label)
 218 {
 219         return snprintf(label, PAGE_SIZE, "%s\n", mt6360_channel_labels[chan->channel]);
 220 }
 221
 222 static const struct iio_info mt6360_adc_iio_info = {
 223         .read_raw = mt6360_adc_read_raw,
 224         .read_label = mt6360_adc_read_label,
 225 };
 226
 227 #define MT6360_ADC_CHAN(_idx, _type) {                          \
 228         .type = _type,                                          \
 229         .channel = MT6360_CHAN_##_idx,                          \
 230         .scan_index = MT6360_CHAN_##_idx,                       \
 231         .datasheet_name = #_idx,                                \
 232         .scan_type =  {                                         \
 233                 .sign = 'u',                                    \
 234                 .realbits = 16,                                 \
 235                 .storagebits = 16,                              \
 236                 .endianness = IIO_CPU,                          \
 237         },                                                      \
 238         .indexed = 1,                                           \
 239         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |          \
 240                                 BIT(IIO_CHAN_INFO_SCALE) |      \
 241                                 BIT(IIO_CHAN_INFO_OFFSET),      \
 242 }
 243
 244 static const struct iio_chan_spec mt6360_adc_channels[] = {
 245         MT6360_ADC_CHAN(USBID, IIO_VOLTAGE),
 246         MT6360_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE),
 247         MT6360_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE),
 248         MT6360_ADC_CHAN(VSYS, IIO_VOLTAGE),
 249         MT6360_ADC_CHAN(VBAT, IIO_VOLTAGE),
 250         MT6360_ADC_CHAN(IBUS, IIO_CURRENT),
 251         MT6360_ADC_CHAN(IBAT, IIO_CURRENT),
 252         MT6360_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE),
 253         MT6360_ADC_CHAN(TEMP_JC, IIO_TEMP),
 254         MT6360_ADC_CHAN(VREF_TS, IIO_VOLTAGE),
 255         MT6360_ADC_CHAN(TS, IIO_VOLTAGE),
 256         IIO_CHAN_SOFT_TIMESTAMP(MT6360_CHAN_MAX),
 257 };
 258
 259 static irqreturn_t mt6360_adc_trigger_handler(int irq, void *p)
 260 {
 261         struct iio_poll_func *pf = p;
 262         struct iio_dev *indio_dev = pf->indio_dev;
 263         struct mt6360_adc_data *mad = iio_priv(indio_dev);
 264         struct {
 265                 u16 values[MT6360_CHAN_MAX];
 266                 int64_t timestamp;
 267         } data __aligned(8);
 268         int i = 0, bit, val, ret;
 269
 270         memset(&data, 0, sizeof(data));
 271         iio_for_each_active_channel(indio_dev, bit) {
 272                 ret = mt6360_adc_read_channel(mad, bit, &val);
 273                 if (ret < 0) {
 274                         dev_warn(&indio_dev->dev, "Failed to get channel %d conversion val\n", bit);
 275                         goto out;
 276                 }
 277
 278                 data.values[i++] = val;
 279         }
 280         iio_push_to_buffers_with_timestamp(indio_dev, &data, iio_get_time_ns(indio_dev));
 281 out:
 282         iio_trigger_notify_done(indio_dev->trig);
 283
 284         return IRQ_HANDLED;
 285 }
 286
 287 static inline int mt6360_adc_reset(struct mt6360_adc_data *info)
 288 {
 289         __be16 adc_enable;
 290         ktime_t all_off_time;
 291         int i, ret;
 292
 293         /* Clear ADC idle wait time to 0 */
 294         ret = regmap_write(info->regmap, MT6360_REG_PMUADCIDLET, 0);
 295         if (ret)
 296                 return ret;
 297
 298         /* Only keep ADC enable, but keep all channels off */
 299         adc_enable = cpu_to_be16(MT6360_ADCEN_MASK);
 300         ret = regmap_raw_write(info->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
 301         if (ret)
 302                 return ret;
 303
 304         /* Reset all channel off time to the current one */
 305         all_off_time = ktime_get();
 306         for (i = 0; i < MT6360_CHAN_MAX; i++)
 307                 info->last_off_timestamps[i] = all_off_time;
 308
 309         return 0;
 310 }
 311
 312 static int mt6360_adc_probe(struct platform_device *pdev)
 313 {
 314         struct mt6360_adc_data *mad;
 315         struct regmap *regmap;
 316         struct iio_dev *indio_dev;
 317         int ret;
 318
 319         regmap = dev_get_regmap(pdev->dev.parent, NULL);
 320         if (!regmap) {
 321                 dev_err(&pdev->dev, "Failed to get parent regmap\n");
 322                 return -ENODEV;
 323         }
 324
 325         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*mad));
 326         if (!indio_dev)
 327                 return -ENOMEM;
 328
 329         mad = iio_priv(indio_dev);
 330         mad->dev = &pdev->dev;
 331         mad->regmap = regmap;
 332         mutex_init(&mad->adc_lock);
 333
 334         ret = mt6360_adc_reset(mad);
 335         if (ret < 0) {
 336                 dev_err(&pdev->dev, "Failed to reset adc\n");
 337                 return ret;
 338         }
 339
 340         indio_dev->name = dev_name(&pdev->dev);
 341         indio_dev->info = &mt6360_adc_iio_info;
 342         indio_dev->modes = INDIO_DIRECT_MODE;
 343         indio_dev->channels = mt6360_adc_channels;
 344         indio_dev->num_channels = ARRAY_SIZE(mt6360_adc_channels);
 345
 346         ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, NULL,
 347                                               mt6360_adc_trigger_handler, NULL);
 348         if (ret) {
 349                 dev_err(&pdev->dev, "Failed to allocate iio trigger buffer\n");
 350                 return ret;
 351         }
 352
 353         return devm_iio_device_register(&pdev->dev, indio_dev);
 354 }
 355
 356 static const struct of_device_id mt6360_adc_of_id[] = {
 357         { .compatible = "mediatek,mt6360-adc", },
 358         { }
 359 };
 360 MODULE_DEVICE_TABLE(of, mt6360_adc_of_id);
 361
 362 static struct platform_driver mt6360_adc_driver = {
 363         .driver = {
 364                 .name = "mt6360-adc",
 365                 .of_match_table = mt6360_adc_of_id,
 366         },
 367         .probe = mt6360_adc_probe,
 368 };
 369 module_platform_driver(mt6360_adc_driver);
 370
 371 MODULE_AUTHOR("Gene Chen <gene_chen@richtek.com>");
 372 MODULE_DESCRIPTION("MT6360 ADC Driver");
 373 MODULE_LICENSE("GPL v2");