Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / iio / pressure / ms5611_core.c

diff --git a/kernel/drivers/iio/pressure/ms5611_core.c b/kernel/drivers/iio/pressure/ms5611_core.c
new file mode 100644 (file)
index 0000000..e42c853
--- /dev/null
+++ b/kernel/drivers/iio/pressure/ms5611_core.c
@@ -0,0 +1,215 @@
+/*
+ * MS5611 pressure and temperature sensor driver
+ *
+ * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Data sheet:
+ *  http://www.meas-spec.com/downloads/MS5611-01BA03.pdf
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/delay.h>
+
+#include "ms5611.h"
+
+static bool ms5611_prom_is_valid(u16 *prom, size_t len)
+{
+       int i, j;
+       uint16_t crc = 0, crc_orig = prom[7] & 0x000F;
+
+       prom[7] &= 0xFF00;
+
+       for (i = 0; i < len * 2; i++) {
+               if (i % 2 == 1)
+                       crc ^= prom[i >> 1] & 0x00FF;
+               else
+                       crc ^= prom[i >> 1] >> 8;
+
+               for (j = 0; j < 8; j++) {
+                       if (crc & 0x8000)
+                               crc = (crc << 1) ^ 0x3000;
+                       else
+                               crc <<= 1;
+               }
+       }
+
+       crc = (crc >> 12) & 0x000F;
+
+       return crc_orig != 0x0000 && crc == crc_orig;
+}
+
+static int ms5611_read_prom(struct iio_dev *indio_dev)
+{
+       int ret, i;
+       struct ms5611_state *st = iio_priv(indio_dev);
+
+       for (i = 0; i < MS5611_PROM_WORDS_NB; i++) {
+               ret = st->read_prom_word(&indio_dev->dev, i, &st->prom[i]);
+               if (ret < 0) {
+                       dev_err(&indio_dev->dev,
+                               "failed to read prom at %d\n", i);
+                       return ret;
+               }
+       }
+
+       if (!ms5611_prom_is_valid(st->prom, MS5611_PROM_WORDS_NB)) {
+               dev_err(&indio_dev->dev, "PROM integrity check failed\n");
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
+                                        s32 *temp, s32 *pressure)
+{
+       int ret;
+       s32 t, p;
+       s64 off, sens, dt;
+       struct ms5611_state *st = iio_priv(indio_dev);
+
+       ret = st->read_adc_temp_and_pressure(&indio_dev->dev, &t, &p);
+       if (ret < 0) {
+               dev_err(&indio_dev->dev,
+                       "failed to read temperature and pressure\n");
+               return ret;
+       }
+
+       dt = t - (st->prom[5] << 8);
+       off = ((s64)st->prom[2] << 16) + ((st->prom[4] * dt) >> 7);
+       sens = ((s64)st->prom[1] << 15) + ((st->prom[3] * dt) >> 8);
+
+       t = 2000 + ((st->prom[6] * dt) >> 23);
+       if (t < 2000) {
+               s64 off2, sens2, t2;
+
+               t2 = (dt * dt) >> 31;
+               off2 = (5 * (t - 2000) * (t - 2000)) >> 1;
+               sens2 = off2 >> 1;
+
+               if (t < -1500) {
+                       s64 tmp = (t + 1500) * (t + 1500);
+
+                       off2 += 7 * tmp;
+                       sens2 += (11 * tmp) >> 1;
+               }
+
+               t -= t2;
+               off -= off2;
+               sens -= sens2;
+       }
+
+       *temp = t;
+       *pressure = (((p * sens) >> 21) - off) >> 15;
+
+       return 0;
+}
+
+static int ms5611_reset(struct iio_dev *indio_dev)
+{
+       int ret;
+       struct ms5611_state *st = iio_priv(indio_dev);
+
+       ret = st->reset(&indio_dev->dev);
+       if (ret < 0) {
+               dev_err(&indio_dev->dev, "failed to reset device\n");
+               return ret;
+       }
+
+       usleep_range(3000, 4000);
+
+       return 0;
+}
+
+static int ms5611_read_raw(struct iio_dev *indio_dev,
+                          struct iio_chan_spec const *chan,
+                          int *val, int *val2, long mask)
+{
+       int ret;
+       s32 temp, pressure;
+       struct ms5611_state *st = iio_priv(indio_dev);
+
+       switch (mask) {
+       case IIO_CHAN_INFO_PROCESSED:
+               mutex_lock(&st->lock);
+               ret = ms5611_read_temp_and_pressure(indio_dev,
+                                                   &temp, &pressure);
+               mutex_unlock(&st->lock);
+               if (ret < 0)
+                       return ret;
+
+               switch (chan->type) {
+               case IIO_TEMP:
+                       *val = temp * 10;
+                       return IIO_VAL_INT;
+               case IIO_PRESSURE:
+                       *val = pressure / 1000;
+                       *val2 = (pressure % 1000) * 1000;
+                       return IIO_VAL_INT_PLUS_MICRO;
+               default:
+                       return -EINVAL;
+               }
+       }
+
+       return -EINVAL;
+}
+
+static const struct iio_chan_spec ms5611_channels[] = {
+       {
+               .type = IIO_PRESSURE,
+               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+                       BIT(IIO_CHAN_INFO_SCALE)
+       },
+       {
+               .type = IIO_TEMP,
+               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+                       BIT(IIO_CHAN_INFO_SCALE)
+       }
+};
+
+static const struct iio_info ms5611_info = {
+       .read_raw = &ms5611_read_raw,
+       .driver_module = THIS_MODULE,
+};
+
+static int ms5611_init(struct iio_dev *indio_dev)
+{
+       int ret;
+
+       ret = ms5611_reset(indio_dev);
+       if (ret < 0)
+               return ret;
+
+       return ms5611_read_prom(indio_dev);
+}
+
+int ms5611_probe(struct iio_dev *indio_dev, struct device *dev)
+{
+       int ret;
+       struct ms5611_state *st = iio_priv(indio_dev);
+
+       mutex_init(&st->lock);
+       indio_dev->dev.parent = dev;
+       indio_dev->name = dev->driver->name;
+       indio_dev->info = &ms5611_info;
+       indio_dev->channels = ms5611_channels;
+       indio_dev->num_channels = ARRAY_SIZE(ms5611_channels);
+       indio_dev->modes = INDIO_DIRECT_MODE;
+
+       ret = ms5611_init(indio_dev);
+       if (ret < 0)
+               return ret;
+
+       return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL(ms5611_probe);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("MS5611 core driver");
+MODULE_LICENSE("GPL v2");