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Commit fa4c9c93 authored by Crestez Dan Leonard's avatar Crestez Dan Leonard Committed by Jonathan Cameron
Browse files

hp206c: Initial support for reading sensor values 



Signed-off-by: default avatarCrestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent d409404c

drivers/iio/pressure/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -148,4 +148,14 @@ config T5403 
	  To compile this driver as a module, choose M here: the module

	  will be called t5403.



config HP206C

	tristate "HOPERF HP206C precision barometer and altimeter sensor"

	depends on I2C

	help

	  Say yes here to build support for the HOPREF HP206C precision

	  barometer and altimeter sensor.



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

	  be called hp206c.



endmenu

drivers/iio/pressure/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o 
st_pressure-y := st_pressure_core.o

st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o

obj-$(CONFIG_T5403) += t5403.o

obj-$(CONFIG_HP206C) += hp206c.o



obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o

obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o

drivers/iio/pressure/hp206c.c

0 → 100644
+426 −0
Original line number Diff line number Diff line 
/*

 * hp206c.c - HOPERF HP206C precision barometer and altimeter sensor

 *

 * Copyright (c) 2016, Intel Corporation.

 *

 * This file is subject to the terms and conditions of version 2 of

 * the GNU General Public License.  See the file COPYING in the main

 * directory of this archive for more details.

 *

 * (7-bit I2C slave address 0x76)

 *

 * Datasheet:

 *  http://www.hoperf.com/upload/sensor/HP206C_DataSheet_EN_V2.0.pdf

 */



#include <linux/module.h>

#include <linux/i2c.h>

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/delay.h>

#include <linux/util_macros.h>

#include <linux/acpi.h>



/* I2C commands: */

#define HP206C_CMD_SOFT_RST	0x06



#define HP206C_CMD_ADC_CVT	0x40



#define HP206C_CMD_ADC_CVT_OSR_4096	0x00

#define HP206C_CMD_ADC_CVT_OSR_2048	0x04

#define HP206C_CMD_ADC_CVT_OSR_1024	0x08

#define HP206C_CMD_ADC_CVT_OSR_512	0x0c

#define HP206C_CMD_ADC_CVT_OSR_256	0x10

#define HP206C_CMD_ADC_CVT_OSR_128	0x14



#define HP206C_CMD_ADC_CVT_CHNL_PT	0x00

#define HP206C_CMD_ADC_CVT_CHNL_T	0x02



#define HP206C_CMD_READ_P	0x30

#define HP206C_CMD_READ_T	0x32



#define HP206C_CMD_READ_REG	0x80

#define HP206C_CMD_WRITE_REG	0xc0



#define HP206C_REG_INT_EN	0x0b

#define HP206C_REG_INT_CFG	0x0c



#define HP206C_REG_INT_SRC	0x0d

#define HP206C_FLAG_DEV_RDY	0x40



#define HP206C_REG_PARA		0x0f

#define HP206C_FLAG_CMPS_EN	0x80



/* Maximum spin for DEV_RDY */

#define HP206C_MAX_DEV_RDY_WAIT_COUNT 20

#define HP206C_DEV_RDY_WAIT_US    20000



struct hp206c_data {

	struct mutex mutex;

	struct i2c_client *client;

	int temp_osr_index;

	int pres_osr_index;

};



struct hp206c_osr_setting {

	u8 osr_mask;

	unsigned int temp_conv_time_us;

	unsigned int pres_conv_time_us;

};



/* Data from Table 5 in datasheet. */

static const struct hp206c_osr_setting hp206c_osr_settings[] = {

	{ HP206C_CMD_ADC_CVT_OSR_4096,	65600,	131100	},

	{ HP206C_CMD_ADC_CVT_OSR_2048,	32800,	65600	},

	{ HP206C_CMD_ADC_CVT_OSR_1024,	16400,	32800	},

	{ HP206C_CMD_ADC_CVT_OSR_512,	8200,	16400	},

	{ HP206C_CMD_ADC_CVT_OSR_256,	4100,	8200	},

	{ HP206C_CMD_ADC_CVT_OSR_128,	2100,	4100	},

};

static const int hp206c_osr_rates[] = { 4096, 2048, 1024, 512, 256, 128 };

static const char hp206c_osr_rates_str[] = "4096 2048 1024 512 256 128";



static inline int hp206c_read_reg(struct i2c_client *client, u8 reg)

{

	return i2c_smbus_read_byte_data(client, HP206C_CMD_READ_REG | reg);

}



static inline int hp206c_write_reg(struct i2c_client *client, u8 reg, u8 val)

{

	return i2c_smbus_write_byte_data(client,

			HP206C_CMD_WRITE_REG | reg, val);

}



static int hp206c_read_20bit(struct i2c_client *client, u8 cmd)

{

	int ret;

	u8 values[3];



	ret = i2c_smbus_read_i2c_block_data(client, cmd, 3, values);

	if (ret < 0)

		return ret;

	if (ret != 3)

		return -EIO;

	return ((values[0] & 0xF) << 16) | (values[1] << 8) | (values[2]);

}



/* Spin for max 160ms until DEV_RDY is 1, or return error. */

static int hp206c_wait_dev_rdy(struct iio_dev *indio_dev)

{

	int ret;

	int count = 0;

	struct hp206c_data *data = iio_priv(indio_dev);

	struct i2c_client *client = data->client;



	while (++count <= HP206C_MAX_DEV_RDY_WAIT_COUNT) {

		ret = hp206c_read_reg(client, HP206C_REG_INT_SRC);

		if (ret < 0) {

			dev_err(&indio_dev->dev, "Failed READ_REG INT_SRC: %d\n", ret);

			return ret;

		}

		if (ret & HP206C_FLAG_DEV_RDY)

			return 0;

		usleep_range(HP206C_DEV_RDY_WAIT_US, HP206C_DEV_RDY_WAIT_US * 3 / 2);

	}

	return -ETIMEDOUT;

}



static int hp206c_set_compensation(struct i2c_client *client, bool enabled)

{

	int val;



	val = hp206c_read_reg(client, HP206C_REG_PARA);

	if (val < 0)

		return val;

	if (enabled)

		val |= HP206C_FLAG_CMPS_EN;

	else

		val &= ~HP206C_FLAG_CMPS_EN;



	return hp206c_write_reg(client, HP206C_REG_PARA, val);

}



/* Do a soft reset */

static int hp206c_soft_reset(struct iio_dev *indio_dev)

{

	int ret;

	struct hp206c_data *data = iio_priv(indio_dev);

	struct i2c_client *client = data->client;



	ret = i2c_smbus_write_byte(client, HP206C_CMD_SOFT_RST);

	if (ret) {

		dev_err(&client->dev, "Failed to reset device: %d\n", ret);

		return ret;

	}



	usleep_range(400, 600);



	ret = hp206c_wait_dev_rdy(indio_dev);

	if (ret) {

		dev_err(&client->dev, "Device not ready after soft reset: %d\n", ret);

		return ret;

	}



	ret = hp206c_set_compensation(client, true);

	if (ret)

		dev_err(&client->dev, "Failed to enable compensation: %d\n", ret);

	return ret;

}



static int hp206c_conv_and_read(struct iio_dev *indio_dev,

				u8 conv_cmd, u8 read_cmd,

				unsigned int sleep_us)

{

	int ret;

	struct hp206c_data *data = iio_priv(indio_dev);

	struct i2c_client *client = data->client;



	ret = hp206c_wait_dev_rdy(indio_dev);

	if (ret < 0) {

		dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);

		return ret;

	}



	ret = i2c_smbus_write_byte(client, conv_cmd);

	if (ret < 0) {

		dev_err(&indio_dev->dev, "Failed convert: %d\n", ret);

		return ret;

	}



	usleep_range(sleep_us, sleep_us * 3 / 2);



	ret = hp206c_wait_dev_rdy(indio_dev);

	if (ret < 0) {

		dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);

		return ret;

	}



	ret = hp206c_read_20bit(client, read_cmd);

	if (ret < 0)

		dev_err(&indio_dev->dev, "Failed read: %d\n", ret);



	return ret;

}



static int hp206c_read_raw(struct iio_dev *indio_dev,

			   struct iio_chan_spec const *chan, int *val,

			   int *val2, long mask)

{

	int ret;

	struct hp206c_data *data = iio_priv(indio_dev);

	const struct hp206c_osr_setting *osr_setting;

	u8 conv_cmd;



	mutex_lock(&data->mutex);



	switch (mask) {

	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:

		switch (chan->type) {

		case IIO_TEMP:

			*val = hp206c_osr_rates[data->temp_osr_index];

			ret = IIO_VAL_INT;

			break;



		case IIO_PRESSURE:

			*val = hp206c_osr_rates[data->pres_osr_index];

			ret = IIO_VAL_INT;

			break;

		default:

			ret = -EINVAL;

		}

		break;



	case IIO_CHAN_INFO_RAW:

		switch (chan->type) {

		case IIO_TEMP:

			osr_setting = &hp206c_osr_settings[data->temp_osr_index];

			conv_cmd = HP206C_CMD_ADC_CVT |

					osr_setting->osr_mask |

					HP206C_CMD_ADC_CVT_CHNL_T;

			ret = hp206c_conv_and_read(indio_dev,

					conv_cmd,

					HP206C_CMD_READ_T,

					osr_setting->temp_conv_time_us);

			if (ret >= 0) {

				/* 20 significant bits are provided.

				 * Extend sign over the rest.

				 */

				*val = sign_extend32(ret, 19);

				ret = IIO_VAL_INT;

			}

			break;



		case IIO_PRESSURE:

			osr_setting = &hp206c_osr_settings[data->pres_osr_index];

			conv_cmd = HP206C_CMD_ADC_CVT |

					osr_setting->osr_mask |

					HP206C_CMD_ADC_CVT_CHNL_PT;

			ret = hp206c_conv_and_read(indio_dev,

					conv_cmd,

					HP206C_CMD_READ_P,

					osr_setting->pres_conv_time_us);

			if (ret >= 0) {

				*val = ret;

				ret = IIO_VAL_INT;

			}

			break;

		default:

			ret = -EINVAL;

		}

		break;



	case IIO_CHAN_INFO_SCALE:

		switch (chan->type) {

		case IIO_TEMP:

			*val = 0;

			*val2 = 10000;

			ret = IIO_VAL_INT_PLUS_MICRO;

			break;



		case IIO_PRESSURE:

			*val = 0;

			*val2 = 1000;

			ret = IIO_VAL_INT_PLUS_MICRO;

			break;

		default:

			ret = -EINVAL;

		}

		break;



	default:

		ret = -EINVAL;

	}



	mutex_unlock(&data->mutex);

	return ret;

}



static int hp206c_write_raw(struct iio_dev *indio_dev,

			    struct iio_chan_spec const *chan,

			    int val, int val2, long mask)

{

	int ret = 0;

	struct hp206c_data *data = iio_priv(indio_dev);



	if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)

		return -EINVAL;

	mutex_lock(&data->mutex);

	switch (chan->type) {

	case IIO_TEMP:

		data->temp_osr_index = find_closest_descending(val,

			hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));

		break;

	case IIO_PRESSURE:

		data->pres_osr_index = find_closest_descending(val,

			hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));

		break;

	default:

		ret = -EINVAL;

	}

	mutex_unlock(&data->mutex);

	return ret;

}



static const struct iio_chan_spec hp206c_channels[] = {

	{

		.type = IIO_TEMP,

		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

				      BIT(IIO_CHAN_INFO_SCALE) |

				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),

	},

	{

		.type = IIO_PRESSURE,

		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

				      BIT(IIO_CHAN_INFO_SCALE) |

				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),

	}

};



static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(hp206c_osr_rates_str);



static struct attribute *hp206c_attributes[] = {

	&iio_const_attr_sampling_frequency_available.dev_attr.attr,

	NULL,

};



static const struct attribute_group hp206c_attribute_group = {

	.attrs = hp206c_attributes,

};



static const struct iio_info hp206c_info = {

	.attrs = &hp206c_attribute_group,

	.read_raw = hp206c_read_raw,

	.write_raw = hp206c_write_raw,

	.driver_module = THIS_MODULE,

};



static int hp206c_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{

	struct iio_dev *indio_dev;

	struct hp206c_data *data;

	int ret;



	if (!i2c_check_functionality(client->adapter,

				     I2C_FUNC_SMBUS_BYTE |

				     I2C_FUNC_SMBUS_BYTE_DATA |

				     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {

		dev_err(&client->dev, "Adapter does not support "

				"all required i2c functionality\n");

		return -ENODEV;

	}



	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));

	if (!indio_dev)

		return -ENOMEM;



	data = iio_priv(indio_dev);

	data->client = client;

	mutex_init(&data->mutex);



	indio_dev->info = &hp206c_info;

	indio_dev->name = id->name;

	indio_dev->dev.parent = &client->dev;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->channels = hp206c_channels;

	indio_dev->num_channels = ARRAY_SIZE(hp206c_channels);



	i2c_set_clientdata(client, indio_dev);



	/* Do a soft reset on probe */

	ret = hp206c_soft_reset(indio_dev);

	if (ret) {

		dev_err(&client->dev, "Failed to reset on startup: %d\n", ret);

		return -ENODEV;

	}



	return devm_iio_device_register(&client->dev, indio_dev);

}



static const struct i2c_device_id hp206c_id[] = {

	{"hp206c"},

	{}

};



#ifdef CONFIG_ACPI

static const struct acpi_device_id hp206c_acpi_match[] = {

	{"HOP206C", 0},

	{ },

};

MODULE_DEVICE_TABLE(acpi, hp206c_acpi_match);

#endif



static struct i2c_driver hp206c_driver = {

	.probe = hp206c_probe,

	.id_table = hp206c_id,

	.driver = {

		.name = "hp206c",

		.acpi_match_table = ACPI_PTR(hp206c_acpi_match),

	},

};



module_i2c_driver(hp206c_driver);



MODULE_DESCRIPTION("HOPERF HP206C precision barometer and altimeter sensor");

MODULE_AUTHOR("Leonard Crestez <leonard.crestez@intel.com>");

MODULE_LICENSE("GPL v2");