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Diffstat (limited to 'drivers/iio/pressure/mprls0025pa.c')
-rw-r--r--drivers/iio/pressure/mprls0025pa.c455
1 files changed, 455 insertions, 0 deletions
diff --git a/drivers/iio/pressure/mprls0025pa.c b/drivers/iio/pressure/mprls0025pa.c
new file mode 100644
index 000000000000..2336f2760eae
--- /dev/null
+++ b/drivers/iio/pressure/mprls0025pa.c
@@ -0,0 +1,455 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MPRLS0025PA - Honeywell MicroPressure pressure sensor series driver
+ *
+ * Copyright (c) Andreas Klinger <ak@it-klinger.de>
+ *
+ * Data sheet:
+ * https://prod-edam.honeywell.com/content/dam/honeywell-edam/sps/siot/en-us/products/sensors/pressure-sensors/board-mount-pressure-sensors/micropressure-mpr-series/documents/sps-siot-mpr-series-datasheet-32332628-ciid-172626.pdf
+ *
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/math64.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/units.h>
+
+#include <linux/gpio/consumer.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include <linux/regulator/consumer.h>
+
+#include <linux/unaligned.h>
+
+#include "mprls0025pa.h"
+
+/* bits in status byte */
+#define MPR_ST_POWER BIT(6) /* device is powered */
+#define MPR_ST_BUSY BIT(5) /* device is busy */
+#define MPR_ST_MEMORY BIT(2) /* integrity test passed */
+#define MPR_ST_MATH BIT(0) /* internal math saturation */
+
+#define MPR_ST_ERR_FLAG (MPR_ST_BUSY | MPR_ST_MEMORY | MPR_ST_MATH)
+
+/*
+ * support _RAW sysfs interface:
+ *
+ * Calculation formula from the datasheet:
+ * pressure = (press_cnt - outputmin) * scale + pmin
+ * with:
+ * * pressure - measured pressure in Pascal
+ * * press_cnt - raw value read from sensor
+ * * pmin - minimum pressure range value of sensor (data->pmin)
+ * * pmax - maximum pressure range value of sensor (data->pmax)
+ * * outputmin - minimum numerical range raw value delivered by sensor
+ * (mpr_func_spec.output_min)
+ * * outputmax - maximum numerical range raw value delivered by sensor
+ * (mpr_func_spec.output_max)
+ * * scale - (pmax - pmin) / (outputmax - outputmin)
+ *
+ * formula of the userspace:
+ * pressure = (raw + offset) * scale
+ *
+ * Values given to the userspace in sysfs interface:
+ * * raw - press_cnt
+ * * offset - (-1 * outputmin) - pmin / scale
+ * note: With all sensors from the datasheet pmin = 0
+ * which reduces the offset to (-1 * outputmin)
+ */
+
+/*
+ * transfer function A: 10% to 90% of 2^24
+ * transfer function B: 2.5% to 22.5% of 2^24
+ * transfer function C: 20% to 80% of 2^24
+ */
+struct mpr_func_spec {
+ u32 output_min;
+ u32 output_max;
+};
+
+static const struct mpr_func_spec mpr_func_spec[] = {
+ [MPR_FUNCTION_A] = { .output_min = 1677722, .output_max = 15099494 },
+ [MPR_FUNCTION_B] = { .output_min = 419430, .output_max = 3774874 },
+ [MPR_FUNCTION_C] = { .output_min = 3355443, .output_max = 13421773 },
+};
+
+enum mpr_variants {
+ MPR0001BA = 0x00, MPR01_6BA = 0x01, MPR02_5BA = 0x02, MPR0060MG = 0x03,
+ MPR0100MG = 0x04, MPR0160MG = 0x05, MPR0250MG = 0x06, MPR0400MG = 0x07,
+ MPR0600MG = 0x08, MPR0001BG = 0x09, MPR01_6BG = 0x0a, MPR02_5BG = 0x0b,
+ MPR0100KA = 0x0c, MPR0160KA = 0x0d, MPR0250KA = 0x0e, MPR0006KG = 0x0f,
+ MPR0010KG = 0x10, MPR0016KG = 0x11, MPR0025KG = 0x12, MPR0040KG = 0x13,
+ MPR0060KG = 0x14, MPR0100KG = 0x15, MPR0160KG = 0x16, MPR0250KG = 0x17,
+ MPR0015PA = 0x18, MPR0025PA = 0x19, MPR0030PA = 0x1a, MPR0001PG = 0x1b,
+ MPR0005PG = 0x1c, MPR0015PG = 0x1d, MPR0030PG = 0x1e, MPR0300YG = 0x1f,
+ MPR_VARIANTS_MAX
+};
+
+static const char * const mpr_triplet_variants[MPR_VARIANTS_MAX] = {
+ [MPR0001BA] = "0001BA", [MPR01_6BA] = "01.6BA", [MPR02_5BA] = "02.5BA",
+ [MPR0060MG] = "0060MG", [MPR0100MG] = "0100MG", [MPR0160MG] = "0160MG",
+ [MPR0250MG] = "0250MG", [MPR0400MG] = "0400MG", [MPR0600MG] = "0600MG",
+ [MPR0001BG] = "0001BG", [MPR01_6BG] = "01.6BG", [MPR02_5BG] = "02.5BG",
+ [MPR0100KA] = "0100KA", [MPR0160KA] = "0160KA", [MPR0250KA] = "0250KA",
+ [MPR0006KG] = "0006KG", [MPR0010KG] = "0010KG", [MPR0016KG] = "0016KG",
+ [MPR0025KG] = "0025KG", [MPR0040KG] = "0040KG", [MPR0060KG] = "0060KG",
+ [MPR0100KG] = "0100KG", [MPR0160KG] = "0160KG", [MPR0250KG] = "0250KG",
+ [MPR0015PA] = "0015PA", [MPR0025PA] = "0025PA", [MPR0030PA] = "0030PA",
+ [MPR0001PG] = "0001PG", [MPR0005PG] = "0005PG", [MPR0015PG] = "0015PG",
+ [MPR0030PG] = "0030PG", [MPR0300YG] = "0300YG"
+};
+
+/**
+ * struct mpr_range_config - list of pressure ranges based on nomenclature
+ * @pmin: lowest pressure that can be measured
+ * @pmax: highest pressure that can be measured
+ */
+struct mpr_range_config {
+ const s32 pmin;
+ const s32 pmax;
+};
+
+/* All min max limits have been converted to pascals */
+static const struct mpr_range_config mpr_range_config[MPR_VARIANTS_MAX] = {
+ [MPR0001BA] = { .pmin = 0, .pmax = 100000 },
+ [MPR01_6BA] = { .pmin = 0, .pmax = 160000 },
+ [MPR02_5BA] = { .pmin = 0, .pmax = 250000 },
+ [MPR0060MG] = { .pmin = 0, .pmax = 6000 },
+ [MPR0100MG] = { .pmin = 0, .pmax = 10000 },
+ [MPR0160MG] = { .pmin = 0, .pmax = 16000 },
+ [MPR0250MG] = { .pmin = 0, .pmax = 25000 },
+ [MPR0400MG] = { .pmin = 0, .pmax = 40000 },
+ [MPR0600MG] = { .pmin = 0, .pmax = 60000 },
+ [MPR0001BG] = { .pmin = 0, .pmax = 100000 },
+ [MPR01_6BG] = { .pmin = 0, .pmax = 160000 },
+ [MPR02_5BG] = { .pmin = 0, .pmax = 250000 },
+ [MPR0100KA] = { .pmin = 0, .pmax = 100000 },
+ [MPR0160KA] = { .pmin = 0, .pmax = 160000 },
+ [MPR0250KA] = { .pmin = 0, .pmax = 250000 },
+ [MPR0006KG] = { .pmin = 0, .pmax = 6000 },
+ [MPR0010KG] = { .pmin = 0, .pmax = 10000 },
+ [MPR0016KG] = { .pmin = 0, .pmax = 16000 },
+ [MPR0025KG] = { .pmin = 0, .pmax = 25000 },
+ [MPR0040KG] = { .pmin = 0, .pmax = 40000 },
+ [MPR0060KG] = { .pmin = 0, .pmax = 60000 },
+ [MPR0100KG] = { .pmin = 0, .pmax = 100000 },
+ [MPR0160KG] = { .pmin = 0, .pmax = 160000 },
+ [MPR0250KG] = { .pmin = 0, .pmax = 250000 },
+ [MPR0015PA] = { .pmin = 0, .pmax = 103421 },
+ [MPR0025PA] = { .pmin = 0, .pmax = 172369 },
+ [MPR0030PA] = { .pmin = 0, .pmax = 206843 },
+ [MPR0001PG] = { .pmin = 0, .pmax = 6895 },
+ [MPR0005PG] = { .pmin = 0, .pmax = 34474 },
+ [MPR0015PG] = { .pmin = 0, .pmax = 103421 },
+ [MPR0030PG] = { .pmin = 0, .pmax = 206843 },
+ [MPR0300YG] = { .pmin = 0, .pmax = 39997 }
+};
+
+static const struct iio_chan_spec mpr_channels[] = {
+ {
+ .type = IIO_PRESSURE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 32,
+ .storagebits = 32,
+ .endianness = IIO_CPU,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static void mpr_reset(struct mpr_data *data)
+{
+ if (data->gpiod_reset) {
+ gpiod_set_value(data->gpiod_reset, 0);
+ udelay(10);
+ gpiod_set_value(data->gpiod_reset, 1);
+ }
+}
+
+/**
+ * mpr_read_pressure() - Read pressure value from sensor
+ * @data: Pointer to private data struct.
+ * @press: Output value read from sensor.
+ *
+ * Reading from the sensor by sending and receiving telegrams.
+ *
+ * If there is an end of conversion (EOC) interrupt registered the function
+ * waits for a maximum of one second for the interrupt.
+ *
+ * Context: The function can sleep and data->lock should be held when calling it
+ * Return:
+ * * 0 - OK, the pressure value could be read
+ * * -ETIMEDOUT - Timeout while waiting for the EOC interrupt or busy flag is
+ * still set after nloops attempts of reading
+ */
+static int mpr_read_pressure(struct mpr_data *data, s32 *press)
+{
+ struct device *dev = data->dev;
+ int ret, i;
+ int nloops = 10;
+
+ reinit_completion(&data->completion);
+
+ ret = data->ops->write(data, MPR_CMD_SYNC, MPR_PKT_SYNC_LEN);
+ if (ret < 0) {
+ dev_err(dev, "error while writing ret: %d\n", ret);
+ return ret;
+ }
+
+ if (data->irq > 0) {
+ ret = wait_for_completion_timeout(&data->completion, HZ);
+ if (!ret) {
+ dev_err(dev, "timeout while waiting for eoc irq\n");
+ return -ETIMEDOUT;
+ }
+ } else {
+ /* wait until status indicates data is ready */
+ for (i = 0; i < nloops; i++) {
+ /*
+ * datasheet only says to wait at least 5 ms for the
+ * data but leave the maximum response time open
+ * --> let's try it nloops (10) times which seems to be
+ * quite long
+ */
+ usleep_range(5000, 10000);
+ ret = data->ops->read(data, MPR_CMD_NOP, 1);
+ if (ret < 0) {
+ dev_err(dev,
+ "error while reading, status: %d\n",
+ ret);
+ return ret;
+ }
+ if (!(data->buffer[0] & MPR_ST_ERR_FLAG))
+ break;
+ }
+ if (i == nloops) {
+ dev_err(dev, "timeout while reading\n");
+ return -ETIMEDOUT;
+ }
+ }
+
+ ret = data->ops->read(data, MPR_CMD_NOP, MPR_PKT_NOP_LEN);
+ if (ret < 0)
+ return ret;
+
+ if (data->buffer[0] & MPR_ST_ERR_FLAG) {
+ dev_err(data->dev,
+ "unexpected status byte %02x\n", data->buffer[0]);
+ return -ETIMEDOUT;
+ }
+
+ *press = get_unaligned_be24(&data->buffer[1]);
+
+ dev_dbg(dev, "received: %*ph cnt: %d\n", ret, data->buffer, *press);
+
+ return 0;
+}
+
+static irqreturn_t mpr_eoc_handler(int irq, void *p)
+{
+ struct mpr_data *data = p;
+
+ complete(&data->completion);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t mpr_trigger_handler(int irq, void *p)
+{
+ int ret;
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct mpr_data *data = iio_priv(indio_dev);
+
+ mutex_lock(&data->lock);
+ ret = mpr_read_pressure(data, &data->chan.pres);
+ if (ret < 0)
+ goto err;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->chan,
+ iio_get_time_ns(indio_dev));
+
+err:
+ mutex_unlock(&data->lock);
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int mpr_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val, int *val2, long mask)
+{
+ int ret;
+ s32 pressure;
+ struct mpr_data *data = iio_priv(indio_dev);
+
+ if (chan->type != IIO_PRESSURE)
+ return -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&data->lock);
+ ret = mpr_read_pressure(data, &pressure);
+ mutex_unlock(&data->lock);
+ if (ret < 0)
+ return ret;
+ *val = pressure;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = data->scale;
+ *val2 = data->scale2;
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = data->offset;
+ *val2 = data->offset2;
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info mpr_info = {
+ .read_raw = &mpr_read_raw,
+};
+
+int mpr_common_probe(struct device *dev, const struct mpr_ops *ops, int irq)
+{
+ int ret;
+ struct mpr_data *data;
+ struct iio_dev *indio_dev;
+ const char *triplet;
+ s64 scale, offset;
+ u32 func;
+
+ 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;
+ data->irq = irq;
+
+ mutex_init(&data->lock);
+ init_completion(&data->completion);
+
+ indio_dev->name = "mprls0025pa";
+ indio_dev->info = &mpr_info;
+ indio_dev->channels = mpr_channels;
+ indio_dev->num_channels = ARRAY_SIZE(mpr_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = devm_regulator_get_enable(dev, "vdd");
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "can't get and enable vdd supply\n");
+
+ ret = data->ops->init(data->dev);
+ if (ret)
+ return ret;
+
+ ret = device_property_read_u32(dev,
+ "honeywell,transfer-function", &func);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "honeywell,transfer-function could not be read\n");
+ data->function = func - 1;
+ if (data->function > MPR_FUNCTION_C)
+ return dev_err_probe(dev, -EINVAL,
+ "honeywell,transfer-function %d invalid\n",
+ data->function);
+
+ ret = device_property_read_string(dev, "honeywell,pressure-triplet",
+ &triplet);
+ if (ret) {
+ ret = device_property_read_u32(dev, "honeywell,pmin-pascal",
+ &data->pmin);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "honeywell,pmin-pascal could not be read\n");
+
+ ret = device_property_read_u32(dev, "honeywell,pmax-pascal",
+ &data->pmax);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "honeywell,pmax-pascal could not be read\n");
+ } else {
+ ret = device_property_match_property_string(dev,
+ "honeywell,pressure-triplet",
+ mpr_triplet_variants,
+ MPR_VARIANTS_MAX);
+ if (ret < 0)
+ return dev_err_probe(dev, -EINVAL,
+ "honeywell,pressure-triplet is invalid\n");
+
+ data->pmin = mpr_range_config[ret].pmin;
+ data->pmax = mpr_range_config[ret].pmax;
+ }
+
+ if (data->pmin >= data->pmax)
+ return dev_err_probe(dev, -EINVAL,
+ "pressure limits are invalid\n");
+
+ data->outmin = mpr_func_spec[data->function].output_min;
+ data->outmax = mpr_func_spec[data->function].output_max;
+
+ /* use 64 bit calculation for preserving a reasonable precision */
+ scale = div_s64(((s64)(data->pmax - data->pmin)) * NANO,
+ data->outmax - data->outmin);
+ data->scale = div_s64_rem(scale, NANO, &data->scale2);
+ /*
+ * multiply with NANO before dividing by scale and later divide by NANO
+ * again.
+ */
+ offset = ((-1LL) * (s64)data->outmin) * NANO -
+ div_s64(div_s64((s64)data->pmin * NANO, scale), NANO);
+ data->offset = div_s64_rem(offset, NANO, &data->offset2);
+
+ if (data->irq > 0) {
+ ret = devm_request_irq(dev, data->irq, mpr_eoc_handler,
+ IRQF_TRIGGER_RISING,
+ dev_name(dev),
+ data);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "request irq %d failed\n", data->irq);
+ }
+
+ data->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(data->gpiod_reset))
+ return dev_err_probe(dev, PTR_ERR(data->gpiod_reset),
+ "request reset-gpio failed\n");
+
+ mpr_reset(data);
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+ mpr_trigger_handler, NULL);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "iio triggered buffer setup failed\n");
+
+ ret = devm_iio_device_register(dev, indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "unable to register iio device\n");
+
+ return 0;
+}
+EXPORT_SYMBOL_NS(mpr_common_probe, "IIO_HONEYWELL_MPRLS0025PA");
+
+MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>");
+MODULE_DESCRIPTION("Honeywell MPR pressure sensor core driver");
+MODULE_LICENSE("GPL");
generated by cgit (git 2.34.1) at 2025-12-26 17:41:05 +0000