iio: Add driver for Infineon DPS310 (ba6ec48e) · Commits · e / devices / android_kernel_fairphone_FP5

MAINTAINERS

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		@@ -7761,6 +7761,12 @@ W: http://industrypack.sourceforge.net
		S: Maintained
		F: drivers/ipack/

		INFINEON DPS310 Driver
		M: Eddie James <eajames@linux.ibm.com>
		L: linux-iio@vger.kernel.org
		F: drivers/iio/pressure/dps310.c
		S: Maintained

		INFINIBAND SUBSYSTEM
		M: Doug Ledford <dledford@redhat.com>
		M: Jason Gunthorpe <jgg@mellanox.com>

drivers/iio/pressure/Kconfig

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		@@ -52,6 +52,17 @@ config IIO_CROS_EC_BARO
		To compile this driver as a module, choose M here: the module
		will be called cros_ec_baro.

		config DPS310
		tristate "Infineon DPS310 pressure and temperature sensor"
		depends on I2C
		select REGMAP_I2C
		help
		Support for the Infineon DPS310 digital barometric pressure sensor.
		It can be accessed over I2C bus.

		This driver can also be built as a module. If so, the module will be
		called dps310.

		config HID_SENSOR_PRESS
		depends on HID_SENSOR_HUB
		select IIO_BUFFER

drivers/iio/pressure/Makefile

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		@@ -9,6 +9,7 @@ obj-$(CONFIG_BMP280) += bmp280.o
		bmp280-objs := bmp280-core.o bmp280-regmap.o
		obj-$(CONFIG_BMP280_I2C) += bmp280-i2c.o
		obj-$(CONFIG_BMP280_SPI) += bmp280-spi.o
		obj-$(CONFIG_DPS310) += dps310.o
		obj-$(CONFIG_IIO_CROS_EC_BARO) += cros_ec_baro.o
		obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o
		obj-$(CONFIG_HP03) += hp03.o

drivers/iio/pressure/dps310.c

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		// SPDX-License-Identifier: GPL-2.0+
		// Copyright IBM Corp 2019
		/*
		* The DPS310 is a barometric pressure and temperature sensor.
		* Currently only reading a single temperature is supported by
		* this driver.
		*
		* https://www.infineon.com/dgdl/?fileId=5546d462576f34750157750826c42242
		*
		* Temperature calculation:
		* c0 * 0.5 + c1 * T_raw / kT °C
		*
		* TODO:
		* - Pressure sensor readings
		* - Optionally support the FIFO
		*/

		#include <linux/i2c.h>
		#include <linux/module.h>
		#include <linux/regmap.h>

		#include <linux/iio/iio.h>
		#include <linux/iio/sysfs.h>

		#define DPS310_DEV_NAME "dps310"

		#define DPS310_PRS_B0 0x00
		#define DPS310_PRS_B1 0x01
		#define DPS310_PRS_B2 0x02
		#define DPS310_TMP_B0 0x03
		#define DPS310_TMP_B1 0x04
		#define DPS310_TMP_B2 0x05
		#define DPS310_PRS_CFG 0x06
		#define DPS310_TMP_CFG 0x07
		#define DPS310_TMP_RATE_BITS GENMASK(6, 4)
		#define DPS310_TMP_PRC_BITS GENMASK(3, 0)
		#define DPS310_TMP_EXT BIT(7)
		#define DPS310_MEAS_CFG 0x08
		#define DPS310_MEAS_CTRL_BITS GENMASK(2, 0)
		#define DPS310_PRS_EN BIT(0)
		#define DPS310_TEMP_EN BIT(1)
		#define DPS310_BACKGROUND BIT(2)
		#define DPS310_PRS_RDY BIT(4)
		#define DPS310_TMP_RDY BIT(5)
		#define DPS310_SENSOR_RDY BIT(6)
		#define DPS310_COEF_RDY BIT(7)
		#define DPS310_CFG_REG 0x09
		#define DPS310_INT_HL BIT(7)
		#define DPS310_TMP_SHIFT_EN BIT(3)
		#define DPS310_PRS_SHIFT_EN BIT(4)
		#define DPS310_FIFO_EN BIT(5)
		#define DPS310_SPI_EN BIT(6)
		#define DPS310_RESET 0x0c
		#define DPS310_RESET_MAGIC 0x09
		#define DPS310_COEF_BASE 0x10
		#define DPS310_COEF_SRC 0x28

		/* Make sure sleep time is <= 20ms for usleep_range */
		#define DPS310_POLL_SLEEP_US(t) min(20000, (t) / 8)
		/* Silently handle error in rate value here */
		#define DPS310_POLL_TIMEOUT_US(rc) ((rc) <= 0 ? 1000000 : 1000000 / (rc))

		#define DPS310_PRS_BASE DPS310_PRS_B0
		#define DPS310_TMP_BASE DPS310_TMP_B0

		/*
		* These values (defined in the spec) indicate how to scale the raw register
		* values for each level of precision available.
		*/
		static const int scale_factors[] = {
		524288,
		1572864,
		3670016,
		7864320,
		253952,
		516096,
		1040384,
		2088960,
		};

		struct dps310_data {
		struct i2c_client *client;
		struct regmap *regmap;
		struct mutex lock; /* Lock for sequential HW access functions */

		s32 c0, c1;
		s32 temp_raw;
		};

		static const struct iio_chan_spec dps310_channels[] = {
		{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) \|
		BIT(IIO_CHAN_INFO_SAMP_FREQ) \|
		BIT(IIO_CHAN_INFO_PROCESSED),
		},
		};

		/* To be called after checking the COEF_RDY bit in MEAS_CFG */
		static int dps310_get_temp_coef(struct dps310_data *data)
		{
		int rc;
		u8 coef[3];
		u32 c0, c1;

		/*
		* Read temperature calibration coefficients c0 and c1 from the
		* COEF register. The numbers are 12-bit 2's compliment numbers
		*/
		rc = regmap_bulk_read(data->regmap, DPS310_COEF_BASE, coef,
		sizeof(coef));
		if (rc < 0)
		return rc;

		c0 = (coef[0] << 4) \| (coef[1] >> 4);
		data->c0 = sign_extend32(c0, 11);

		c1 = ((coef[1] & GENMASK(3, 0)) << 8) \| coef[2];
		data->c1 = sign_extend32(c1, 11);

		return 0;
		}

		static int dps310_get_temp_precision(struct dps310_data *data)
		{
		int rc;
		int val;

		rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val);
		if (rc < 0)
		return rc;

		/*
		* Scale factor is bottom 4 bits of the register, but 1111 is
		* reserved so just grab bottom three
		*/
		return BIT(val & GENMASK(2, 0));
		}

		/* Called with lock held */
		static int dps310_set_temp_precision(struct dps310_data *data, int val)
		{
		int rc;
		u8 shift_en;

		if (val < 0 \|\| val > 128)
		return -EINVAL;

		shift_en = val >= 16 ? DPS310_TMP_SHIFT_EN : 0;
		rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
		DPS310_TMP_SHIFT_EN, shift_en);
		if (rc)
		return rc;

		return regmap_update_bits(data->regmap, DPS310_TMP_CFG,
		DPS310_TMP_PRC_BITS, ilog2(val));
		}

		/* Called with lock held */
		static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq)
		{
		u8 val;

		if (freq < 0 \|\| freq > 128)
		return -EINVAL;

		val = ilog2(freq) << 4;

		return regmap_update_bits(data->regmap, DPS310_TMP_CFG,
		DPS310_TMP_RATE_BITS, val);
		}

		static int dps310_get_temp_samp_freq(struct dps310_data *data)
		{
		int rc;
		int val;

		rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val);
		if (rc < 0)
		return rc;

		return BIT((val & DPS310_TMP_RATE_BITS) >> 4);
		}

		static int dps310_get_temp_k(struct dps310_data *data)
		{
		int rc = dps310_get_temp_precision(data);

		if (rc < 0)
		return rc;

		return scale_factors[ilog2(rc)];
		}

		static int dps310_read_temp(struct dps310_data *data)
		{
		int rc;
		int rate;
		int ready;
		int timeout;
		s32 raw;
		u8 val[3];

		if (mutex_lock_interruptible(&data->lock))
		return -EINTR;

		rate = dps310_get_temp_samp_freq(data);
		timeout = DPS310_POLL_TIMEOUT_US(rate);

		/* Poll for sensor readiness; base the timeout upon the sample rate. */
		rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
		ready & DPS310_TMP_RDY,
		DPS310_POLL_SLEEP_US(timeout), timeout);
		if (rc < 0)
		goto done;

		rc = regmap_bulk_read(data->regmap, DPS310_TMP_BASE, val, sizeof(val));
		if (rc < 0)
		goto done;

		raw = (val[0] << 16) \| (val[1] << 8) \| val[2];
		data->temp_raw = sign_extend32(raw, 23);

		done:
		mutex_unlock(&data->lock);
		return rc;
		}

		static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case DPS310_PRS_CFG:
		case DPS310_TMP_CFG:
		case DPS310_MEAS_CFG:
		case DPS310_CFG_REG:
		case DPS310_RESET:
		return true;
		default:
		return false;
		}
		}

		static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case DPS310_PRS_B0:
		case DPS310_PRS_B1:
		case DPS310_PRS_B2:
		case DPS310_TMP_B0:
		case DPS310_TMP_B1:
		case DPS310_TMP_B2:
		case DPS310_MEAS_CFG:
		return true;
		default:
		return false;
		}
		}

		static int dps310_write_raw(struct iio_dev *iio,
		struct iio_chan_spec const *chan, int val,
		int val2, long mask)
		{
		int rc;
		struct dps310_data *data = iio_priv(iio);

		if (chan->type != IIO_TEMP)
		return -EINVAL;

		if (mutex_lock_interruptible(&data->lock))
		return -EINTR;

		switch (mask) {
		case IIO_CHAN_INFO_SAMP_FREQ:
		rc = dps310_set_temp_samp_freq(data, val);
		break;

		case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		rc = dps310_set_temp_precision(data, val);
		break;

		default:
		rc = -EINVAL;
		break;
		}

		mutex_unlock(&data->lock);
		return rc;
		}

		static int dps310_calculate_temp(struct dps310_data *data)
		{
		s64 c0;
		s64 t;
		int kt = dps310_get_temp_k(data);

		if (kt < 0)
		return kt;

		/* Obtain inverse-scaled offset */
		c0 = div_s64((s64)kt * (s64)data->c0, 2);

		/* Add the offset to the unscaled temperature */
		t = c0 + ((s64)data->temp_raw * (s64)data->c1);

		/* Convert to milliCelsius and scale the temperature */
		return (int)div_s64(t * 1000LL, kt);
		}

		static int dps310_read_raw(struct iio_dev *iio,
		struct iio_chan_spec const *chan,
		int val, int val2, long mask)
		{
		struct dps310_data *data = iio_priv(iio);
		int rc;

		switch (mask) {
		case IIO_CHAN_INFO_SAMP_FREQ:
		rc = dps310_get_temp_samp_freq(data);
		if (rc < 0)
		return rc;

		*val = rc;
		return IIO_VAL_INT;

		case IIO_CHAN_INFO_PROCESSED:
		rc = dps310_read_temp(data);
		if (rc)
		return rc;

		rc = dps310_calculate_temp(data);
		if (rc < 0)
		return rc;

		*val = rc;
		return IIO_VAL_INT;

		case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		rc = dps310_get_temp_precision(data);
		if (rc < 0)
		return rc;

		*val = rc;
		return IIO_VAL_INT;

		default:
		return -EINVAL;
		}
		}

		static void dps310_reset(void *action_data)
		{
		struct dps310_data *data = action_data;

		regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC);
		}

		static const struct regmap_config dps310_regmap_config = {
		.reg_bits = 8,
		.val_bits = 8,
		.writeable_reg = dps310_is_writeable_reg,
		.volatile_reg = dps310_is_volatile_reg,
		.cache_type = REGCACHE_RBTREE,
		.max_register = DPS310_COEF_SRC,
		};

		static const struct iio_info dps310_info = {
		.read_raw = dps310_read_raw,
		.write_raw = dps310_write_raw,
		};

		static int dps310_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct dps310_data *data;
		struct iio_dev *iio;
		int rc, ready;

		iio = devm_iio_device_alloc(&client->dev, sizeof(*data));
		if (!iio)
		return -ENOMEM;

		data = iio_priv(iio);
		data->client = client;
		mutex_init(&data->lock);

		iio->dev.parent = &client->dev;
		iio->name = id->name;
		iio->channels = dps310_channels;
		iio->num_channels = ARRAY_SIZE(dps310_channels);
		iio->info = &dps310_info;
		iio->modes = INDIO_DIRECT_MODE;

		data->regmap = devm_regmap_init_i2c(client, &dps310_regmap_config);
		if (IS_ERR(data->regmap))
		return PTR_ERR(data->regmap);

		/* Register to run the device reset when the device is removed */
		rc = devm_add_action_or_reset(&client->dev, dps310_reset, data);
		if (rc)
		return rc;

		/*
		* Set up external (MEMS) temperature sensor in single sample, one
		* measurement per second mode
		*/
		rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
		if (rc < 0)
		return rc;

		/* Temp shift is disabled when PRC <= 8 */
		rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
		DPS310_TMP_SHIFT_EN, 0);
		if (rc < 0)
		return rc;

		/* MEAS_CFG doesn't update correctly unless first written with 0 */
		rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
		DPS310_MEAS_CTRL_BITS, 0);
		if (rc < 0)
		return rc;

		/* Turn on temperature measurement in the background */
		rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
		DPS310_MEAS_CTRL_BITS,
		DPS310_TEMP_EN \| DPS310_BACKGROUND);
		if (rc < 0)
		return rc;

		/*
		* Calibration coefficients required for reporting temperature.
		* They are available 40ms after the device has started
		*/
		rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
		ready & DPS310_COEF_RDY, 10000, 40000);
		if (rc < 0)
		return rc;

		rc = dps310_get_temp_coef(data);
		if (rc < 0)
		return rc;

		rc = devm_iio_device_register(&client->dev, iio);
		if (rc)
		return rc;

		i2c_set_clientdata(client, iio);

		return 0;
		}

		static const struct i2c_device_id dps310_id[] = {
		{ DPS310_DEV_NAME, 0 },
		{}
		};
		MODULE_DEVICE_TABLE(i2c, dps310_id);

		static struct i2c_driver dps310_driver = {
		.driver = {
		.name = DPS310_DEV_NAME,
		},
		.probe = dps310_probe,
		.id_table = dps310_id,
		};
		module_i2c_driver(dps310_driver);

		MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
		MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor");
		MODULE_LICENSE("GPL v2");