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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/iio/pressure/mpl115.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/iio/pressure/mpl115.c')
-rw-r--r--drivers/iio/pressure/mpl115.c194
1 files changed, 194 insertions, 0 deletions
diff --git a/drivers/iio/pressure/mpl115.c b/drivers/iio/pressure/mpl115.c
new file mode 100644
index 000000000..5bf5b9abe
--- /dev/null
+++ b/drivers/iio/pressure/mpl115.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * mpl115.c - Support for Freescale MPL115A pressure/temperature sensor
+ *
+ * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
+ *
+ * TODO: shutdown pin
+ */
+
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/delay.h>
+
+#include "mpl115.h"
+
+#define MPL115_PADC 0x00 /* pressure ADC output value, MSB first, 10 bit */
+#define MPL115_TADC 0x02 /* temperature ADC output value, MSB first, 10 bit */
+#define MPL115_A0 0x04 /* 12 bit integer, 3 bit fraction */
+#define MPL115_B1 0x06 /* 2 bit integer, 13 bit fraction */
+#define MPL115_B2 0x08 /* 1 bit integer, 14 bit fraction */
+#define MPL115_C12 0x0a /* 0 bit integer, 13 bit fraction */
+#define MPL115_CONVERT 0x12 /* convert temperature and pressure */
+
+struct mpl115_data {
+ struct device *dev;
+ struct mutex lock;
+ s16 a0;
+ s16 b1, b2;
+ s16 c12;
+ const struct mpl115_ops *ops;
+};
+
+static int mpl115_request(struct mpl115_data *data)
+{
+ int ret = data->ops->write(data->dev, MPL115_CONVERT, 0);
+
+ if (ret < 0)
+ return ret;
+
+ usleep_range(3000, 4000);
+
+ return 0;
+}
+
+static int mpl115_comp_pressure(struct mpl115_data *data, int *val, int *val2)
+{
+ int ret;
+ u16 padc, tadc;
+ int a1, y1, pcomp;
+ unsigned kpa;
+
+ mutex_lock(&data->lock);
+ ret = mpl115_request(data);
+ if (ret < 0)
+ goto done;
+
+ ret = data->ops->read(data->dev, MPL115_PADC);
+ if (ret < 0)
+ goto done;
+ padc = ret >> 6;
+
+ ret = data->ops->read(data->dev, MPL115_TADC);
+ if (ret < 0)
+ goto done;
+ tadc = ret >> 6;
+
+ /* see Freescale AN3785 */
+ a1 = data->b1 + ((data->c12 * tadc) >> 11);
+ y1 = (data->a0 << 10) + a1 * padc;
+
+ /* compensated pressure with 4 fractional bits */
+ pcomp = (y1 + ((data->b2 * (int) tadc) >> 1)) >> 9;
+
+ kpa = pcomp * (115 - 50) / 1023 + (50 << 4);
+ *val = kpa >> 4;
+ *val2 = (kpa & 15) * (1000000 >> 4);
+done:
+ mutex_unlock(&data->lock);
+ return ret;
+}
+
+static int mpl115_read_temp(struct mpl115_data *data)
+{
+ int ret;
+
+ mutex_lock(&data->lock);
+ ret = mpl115_request(data);
+ if (ret < 0)
+ goto done;
+ ret = data->ops->read(data->dev, MPL115_TADC);
+done:
+ mutex_unlock(&data->lock);
+ return ret;
+}
+
+static int mpl115_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct mpl115_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ ret = mpl115_comp_pressure(data, val, val2);
+ if (ret < 0)
+ return ret;
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_RAW:
+ /* temperature -5.35 C / LSB, 472 LSB is 25 C */
+ ret = mpl115_read_temp(data);
+ if (ret < 0)
+ return ret;
+ *val = ret >> 6;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = -605;
+ *val2 = 750000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_SCALE:
+ *val = -186;
+ *val2 = 915888;
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+ return -EINVAL;
+}
+
+static const struct iio_chan_spec mpl115_channels[] = {
+ {
+ .type = IIO_PRESSURE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ },
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_type =
+ BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE),
+ },
+};
+
+static const struct iio_info mpl115_info = {
+ .read_raw = &mpl115_read_raw,
+};
+
+int mpl115_probe(struct device *dev, const char *name,
+ const struct mpl115_ops *ops)
+{
+ struct mpl115_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ data->dev = dev;
+ data->ops = ops;
+ mutex_init(&data->lock);
+
+ indio_dev->info = &mpl115_info;
+ indio_dev->name = name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = mpl115_channels;
+ indio_dev->num_channels = ARRAY_SIZE(mpl115_channels);
+
+ ret = data->ops->init(data->dev);
+ if (ret)
+ return ret;
+
+ ret = data->ops->read(data->dev, MPL115_A0);
+ if (ret < 0)
+ return ret;
+ data->a0 = ret;
+ ret = data->ops->read(data->dev, MPL115_B1);
+ if (ret < 0)
+ return ret;
+ data->b1 = ret;
+ ret = data->ops->read(data->dev, MPL115_B2);
+ if (ret < 0)
+ return ret;
+ data->b2 = ret;
+ ret = data->ops->read(data->dev, MPL115_C12);
+ if (ret < 0)
+ return ret;
+ data->c12 = ret;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS_GPL(mpl115_probe, IIO_MPL115);
+
+MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
+MODULE_DESCRIPTION("Freescale MPL115 pressure/temperature driver");
+MODULE_LICENSE("GPL");