diff mbox

[RFC] hwmon: Add driver for Infineon DPS310

Message ID 20170426143321.32000-1-joel@jms.id.au
State New
Headers show

Commit Message

Joel Stanley April 26, 2017, 2:33 p.m. UTC
Hi Guenter,

Below is a work in progress hwmon driver for the DPS310[1]. The device does
both pressure and temperature monitoring over either I2C or SPI. There's a
public datasheet available on Infineon's website.

I require a driver that reads the temperature data over I2C and exposes it to
userspace as a hwmon device. I wanted your opinion weather this should be an
IIO driver (and we could then use the IIO HWMON bridge in our application), or
if it should be a native HWMON driver?

Once we've agreed on a subsystem I will clean the driver up and submit it
properly.

Cheers,

Joel

[1] https://www.infineon.com/cms/en/product/sensor/capacitive-pressure-sensor-for-consumer-applications/channel.html

---

The DPS310 is a temperature and pressure sensor. It can be accessed over
i2c and SPI.

This driver supports continual measurement of temperature over i2c only.

Signed-off-by: Joel Stanley <joel@jms.id.au>

---
 drivers/hwmon/Kconfig  |  12 ++
 drivers/hwmon/Makefile |   1 +
 drivers/hwmon/dps310.c | 331 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 344 insertions(+)
 create mode 100644 drivers/hwmon/dps310.c

-- 
2.11.0

Comments

Guenter Roeck April 26, 2017, 3:13 p.m. UTC | #1
Hi Joel,

On Thu, Apr 27, 2017 at 12:03:21AM +0930, Joel Stanley wrote:
> Hi Guenter,

> 

> Below is a work in progress hwmon driver for the DPS310[1]. The device does

> both pressure and temperature monitoring over either I2C or SPI. There's a

> public datasheet available on Infineon's website.

> 

> I require a driver that reads the temperature data over I2C and exposes it to

> userspace as a hwmon device. I wanted your opinion weather this should be an

> IIO driver (and we could then use the IIO HWMON bridge in our application), or

> if it should be a native HWMON driver?

> 


IIO, I think. Pressure isn't really for hardware monitoring, and we would have
a hard time supporting it. IIO already has the necessary infrastructure for it.

Jonathan, any thoughts/comments ?

Thanks,
Guenter

> Once we've agreed on a subsystem I will clean the driver up and submit it

> properly.

> 

> Cheers,

> 

> Joel

> 

> [1] https://www.infineon.com/cms/en/product/sensor/capacitive-pressure-sensor-for-consumer-applications/channel.html

> 

> ---

> 

> The DPS310 is a temperature and pressure sensor. It can be accessed over

> i2c and SPI.

> 

> This driver supports continual measurement of temperature over i2c only.

> 

> Signed-off-by: Joel Stanley <joel@jms.id.au>

> ---

>  drivers/hwmon/Kconfig  |  12 ++

>  drivers/hwmon/Makefile |   1 +

>  drivers/hwmon/dps310.c | 331 +++++++++++++++++++++++++++++++++++++++++++++++++

>  3 files changed, 344 insertions(+)

>  create mode 100644 drivers/hwmon/dps310.c

> 

> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig

> index 190d270b20a2..8229b2f8c591 100644

> --- a/drivers/hwmon/Kconfig

> +++ b/drivers/hwmon/Kconfig

> @@ -1349,6 +1349,18 @@ config SENSORS_DME1737

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

>  	  will be called dme1737.

>  

> +config SENSORS_DPS310

> +	tristate "Infineon DPS310"

> +	depends on I2C

> +	select HWMON_VID

> +	select REGMAP_I2C

> +	help

> +	  If you say yes here you get support for the hardware monitoring

> +	  features of the Infineon DPS310 digital barometric pressure sensor.

> +

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

> +	  will be called dps310.

> +

>  config SENSORS_EMC1403

>  	tristate "SMSC EMC1403/23 thermal sensor"

>  	depends on I2C

> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile

> index d2cb7e804a0f..3a5ad06d6d89 100644

> --- a/drivers/hwmon/Makefile

> +++ b/drivers/hwmon/Makefile

> @@ -52,6 +52,7 @@ obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o

>  obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o

>  obj-$(CONFIG_SENSORS_DELL_SMM)	+= dell-smm-hwmon.o

>  obj-$(CONFIG_SENSORS_DME1737)	+= dme1737.o

> +obj-$(CONFIG_SENSORS_DPS310)	+= dps310.o

>  obj-$(CONFIG_SENSORS_DS620)	+= ds620.o

>  obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o

>  obj-$(CONFIG_SENSORS_EMC1403)	+= emc1403.o

> diff --git a/drivers/hwmon/dps310.c b/drivers/hwmon/dps310.c

> new file mode 100644

> index 000000000000..b014f01d0d3f

> --- /dev/null

> +++ b/drivers/hwmon/dps310.c

> @@ -0,0 +1,331 @@

> +/*

> + * Copyright 2017 IBM Corporation

> + *

> + * Joel Stanley <joel@jms.id.au>

> + *

> + * The DPS310 is a barometric pressure and temperature sensor.

> + *

> + * This program is free software; you can redistribute it and/or

> + * modify it under the terms of the GNU General Public License

> + * as published by the Free Software Foundation; either version

> + * 2 of the License, or (at your option) any later version.

> + */

> +

> +#include <linux/i2c.h>

> +#include <linux/regmap.h>

> +#include <linux/hwmon.h>

> +#include <linux/module.h>

> +

> +#define PRS_B2		0x00

> +#define PRS_B1		0x01

> +#define PRS_B0		0x02

> +#define TMP_B2		0x03

> +#define TMP_B1		0x04

> +#define TMP_B0		0x05

> +#define PRS_CFG		0x06

> +#define TMP_CFG		0x07

> +#define  TMP_RATE_BITS	GENMASK(6, 4)

> +#define  TMP_EXT	BIT(7)

> +#define MEAS_CFG	0x08

> +#define  MEAS_CTRL_BITS	GENMASK(2, 0)

> +#define   PRESSURE_EN	BIT(0)

> +#define   TEMP_EN	BIT(1)

> +#define   BACKGROUND	BIT(2)

> +#define  PRS_RDY	BIT(4)

> +#define  TMP_RDY	BIT(5)

> +#define  SENSOR_RDY	BIT(6)

> +#define  COEF_RDY	BIT(7)

> +#define RESET		0x0c

> +#define  RESET_MAGIC	(BIT(0) | BIT(3))

> +#define COEF_BASE	0x10

> +

> +#define TMP_BASE	TMP_B2

> +#define PRS_BASE	PRS_B2

> +

> +#define TMP_RATE(_n)	ilog2(_n)

> +#define TMP_PRC(_n)	ilog2(_n)

> +

> +const int scale_factor[] = {

> +	 524288,

> +	1572864,

> +	3670016,

> +	7864320,

> +	 253952,

> +	 516096,

> +	1040384,

> +	2088960,

> +};

> +

> +struct dps310_data {

> +	struct regmap *regmap;

> +	int interval;

> +	s32 c0, c1;

> +};

> +

> +static s32 dps310_twos_compliment(u32 raw, size_t num_bits)

> +{

> +	s32 out = raw;

> +

> +	if (raw & BIT(num_bits - 1))

> +		out = raw - BIT(num_bits);

> +

> +	return out;

> +}

> +

> +static int dps310_get_temp_coef(struct dps310_data *data)

> +{

> +	struct regmap *regmap = data->regmap;

> +	uint8_t coef[3] = {0};

> +	int ready, r;

> +	u32 c0, c1;

> +

> +	r = regmap_read(regmap, MEAS_CFG, &ready);

> +	if (r < 0)

> +		return r;

> +

> +	if (!(ready & COEF_RDY))

> +		return -EAGAIN;

> +

> +	/*

> +	 * Read temperature calibration coefficients c0 and c1 from the

> +	 * COEF register. The numbers are 12-bit 2's compliment numbers

> +	 */

> +	r = regmap_bulk_read(regmap, COEF_BASE, coef, 3);

> +	if (r < 0)

> +		return r;

> +

> +	c0 = (coef[0] << 4) | (coef[1] >> 4);

> +	data->c0 = dps310_twos_compliment(c0, 12);

> +

> +	c1 = ((coef[1] & GENMASK(3, 0)) << 8) | coef[2];

> +	data->c1 = dps310_twos_compliment(c1, 12);

> +

> +	return 0;

> +}

> +

> +static int dps310_get_scale_factor(struct device *dev)

> +{

> +	struct dps310_data *data = dev_get_drvdata(dev);

> +	int val, r;

> +

> +	r = regmap_read(data->regmap, TMP_CFG, &val);

> +	if (r < 0)

> +		return r;

> +

> +	/* Scale factor is bottom 4 bits of the register */

> +	val = val & GENMASK(3, 0);

> +	if (val < 0 || val > ARRAY_SIZE(scale_factor))

> +		return -EINVAL;

> +

> +	return scale_factor[val];

> +}

> +

> +static int dps310_read_temp(struct device *dev, u32 attr, int channel,

> +			     long *temp)

> +{

> +	struct dps310_data *data = dev_get_drvdata(dev);

> +	struct regmap *regmap = data->regmap;

> +	uint8_t val[3] = {0};

> +	int r, ready;

> +	int kT, T_raw;

> +

> +	switch (attr) {

> +	case hwmon_temp_input:

> +		r = regmap_read(regmap, MEAS_CFG, &ready);

> +		if (r < 0)

> +			return r;

> +		if (!(ready & TMP_RDY)) {

> +			dev_err(dev, "tmp not ready\n");

> +			return -EAGAIN;

> +		}

> +

> +		/* Choose scaling factor kT based on chosen precision rate */

> +		kT = dps310_get_scale_factor(dev);

> +

> +		r = regmap_bulk_read(regmap, TMP_BASE, val, 3);

> +		if (r < 0)

> +			return r;

> +		T_raw = (val[0] << 16) | (val[1] << 8) | val[2];

> +		T_raw = dps310_twos_compliment(T_raw, 24);

> +

> +		/* (c0 * 0.5 + c1 * T_raw / kT) * 1000 m°C */

> +		*temp = ((data->c0 >> 1) + (data->c1 * T_raw) / kT) * 1000;

> +

> +		return 0;

> +	default:

> +		return -EOPNOTSUPP;

> +	}

> +}

> +

> +static int dps310_read(struct device *dev, enum hwmon_sensor_types type,

> +			u32 attr, int channel, long *val)

> +{

> +	switch (type) {

> +	case hwmon_temp:

> +		return dps310_read_temp(dev, attr, channel, val);

> +	default:

> +		return -EOPNOTSUPP;

> +	}

> +}

> +

> +static int dps310_write(struct device *dev, enum hwmon_sensor_types type,

> +			 u32 attr, int channel, long val)

> +{

> +	switch (type) {

> +	case hwmon_temp:

> +		/* Fall through */

> +	default:

> +		return -EOPNOTSUPP;

> +	}

> +}

> +

> +static umode_t dps310_is_visible(const void *data,

> +				  enum hwmon_sensor_types type,

> +				  u32 attr, int channel)

> +{

> +	switch (type) {

> +	case hwmon_temp:

> +		switch (attr) {

> +		case hwmon_temp_input:

> +			return 0444;

> +		default:

> +			return 0;

> +		}

> +	default:

> +		return 0;

> +	}

> +}

> +

> +

> +static const u32 dps310_temp_config[] = {

> +	HWMON_T_INPUT,

> +	0

> +};

> +

> +static const struct hwmon_channel_info dps310_temp = {

> +	.type = hwmon_temp,

> +	.config = dps310_temp_config,

> +};

> +

> +static const struct hwmon_channel_info *dps310_info[] = {

> +	&dps310_temp,

> +	NULL

> +};

> +

> +static const struct hwmon_ops dps310_hwmon_ops = {

> +	.is_visible = dps310_is_visible,

> +	.read = dps310_read,

> +	.write = dps310_write,

> +};

> +

> +static const struct hwmon_chip_info dps310_chip_info = {

> +	.ops = &dps310_hwmon_ops,

> +	.info = dps310_info,

> +};

> +

> +static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg)

> +{

> +	switch (reg) {

> +	case PRS_CFG:

> +	case TMP_CFG:

> +	case MEAS_CFG:

> +	case RESET:

> +		return true;

> +	default:

> +		return false;

> +	}

> +}

> +

> +static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg)

> +{

> +	switch (reg) {

> +	case PRS_B2:

> +	case PRS_B1:

> +	case PRS_B0:

> +	case TMP_B2:

> +	case TMP_B1:

> +	case TMP_B0:

> +	case MEAS_CFG:

> +		return true;

> +	default:

> +		return false;

> +	}

> +}

> +

> +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,

> +	.use_single_rw = true,

> +};

> +

> +static int dps310_probe(struct i2c_client *client,

> +			const struct i2c_device_id *id)

> +{

> +	struct dps310_data *data;

> +	struct device *hwmon_dev;

> +	int r;

> +

> +	data = devm_kzalloc(&client->dev,  sizeof(*data), GFP_KERNEL);

> +	if (!data)

> +		return -ENOMEM;

> +

> +	data->regmap = devm_regmap_init_i2c(client, &dps310_regmap_config);

> +	if (IS_ERR(data->regmap))

> +		return PTR_ERR(data->regmap);

> +

> +	r = regmap_write(data->regmap, TMP_CFG, TMP_EXT | TMP_PRC(128));

> +	if (r < 0)

> +		return r;

> +

> +	/* Turn on background temperature measurement */

> +	r = regmap_update_bits(data->regmap, MEAS_CFG, MEAS_CTRL_BITS,

> +			TEMP_EN);

> +	if (r < 0)

> +		return r;

> +

> +	/* Get calibration coefficients required for reporting temperature */

> +	r = dps310_get_temp_coef(data);

> +	if (r == -EAGAIN)

> +		return -EPROBE_DEFER;

> +	if (r < 0)

> +		return r;

> +

> +	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,

> +			client->name, data, &dps310_chip_info, NULL);

> +

> +	if (IS_ERR(hwmon_dev))

> +		return PTR_ERR(hwmon_dev);

> +

> +	dev_info(&client->dev, "%s: sensor '%s'\n", dev_name(hwmon_dev),

> +			client->name);

> +

> +	return 0;

> +}

> +

> +static const struct i2c_device_id dps310_id[] = {

> +	{ "dps310", 0 },

> +	{}

> +};

> +MODULE_DEVICE_TABLE(i2c, dps310_id);

> +

> +static const unsigned short normal_i2c[] = {

> +	0x77, 0x76, I2C_CLIENT_END

> +};

> +

> +static struct i2c_driver dps310_driver = {

> +	.class = I2C_CLASS_HWMON,

> +	.driver = {

> +		.name = "dps310",

> +	},

> +	.probe = dps310_probe,

> +	.address_list = normal_i2c,

> +	.id_table = dps310_id,

> +};

> +module_i2c_driver(dps310_driver);

> +

> +MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");

> +MODULE_DESCRIPTION("Infineon DPS310 driver");

> +MODULE_LICENSE("GPL");

> -- 

> 2.11.0

>
Jonathan Cameron April 27, 2017, 6:19 a.m. UTC | #2
On 26/04/17 16:13, Guenter Roeck wrote:
> Hi Joel,

> 

> On Thu, Apr 27, 2017 at 12:03:21AM +0930, Joel Stanley wrote:

>> Hi Guenter,

>>

>> Below is a work in progress hwmon driver for the DPS310[1]. The device does

>> both pressure and temperature monitoring over either I2C or SPI. There's a

>> public datasheet available on Infineon's website.

>>

>> I require a driver that reads the temperature data over I2C and exposes it to

>> userspace as a hwmon device. I wanted your opinion weather this should be an

>> IIO driver (and we could then use the IIO HWMON bridge in our application), or

>> if it should be a native HWMON driver?

>>

> 

> IIO, I think. Pressure isn't really for hardware monitoring, and we would have

> a hard time supporting it. IIO already has the necessary infrastructure for it.

> 

> Jonathan, any thoughts/comments ?

> 

Agree with you.  Pressure doesn't really fit in hwmon, so IIO is best location.
> Thanks,

> Guenter

> 

>> Once we've agreed on a subsystem I will clean the driver up and submit it

>> properly.

>>

>> Cheers,

>>

>> Joel

>>

>> [1] https://www.infineon.com/cms/en/product/sensor/capacitive-pressure-sensor-for-consumer-applications/channel.html

>>

>> ---

>>

>> The DPS310 is a temperature and pressure sensor. It can be accessed over

>> i2c and SPI.

>>

>> This driver supports continual measurement of temperature over i2c only.

>>

>> Signed-off-by: Joel Stanley <joel@jms.id.au>

>> ---

>>  drivers/hwmon/Kconfig  |  12 ++

>>  drivers/hwmon/Makefile |   1 +

>>  drivers/hwmon/dps310.c | 331 +++++++++++++++++++++++++++++++++++++++++++++++++

>>  3 files changed, 344 insertions(+)

>>  create mode 100644 drivers/hwmon/dps310.c

>>

>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig

>> index 190d270b20a2..8229b2f8c591 100644

>> --- a/drivers/hwmon/Kconfig

>> +++ b/drivers/hwmon/Kconfig

>> @@ -1349,6 +1349,18 @@ config SENSORS_DME1737

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

>>  	  will be called dme1737.

>>  

>> +config SENSORS_DPS310

>> +	tristate "Infineon DPS310"

>> +	depends on I2C

>> +	select HWMON_VID

>> +	select REGMAP_I2C

>> +	help

>> +	  If you say yes here you get support for the hardware monitoring

>> +	  features of the Infineon DPS310 digital barometric pressure sensor.

>> +

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

>> +	  will be called dps310.

>> +

>>  config SENSORS_EMC1403

>>  	tristate "SMSC EMC1403/23 thermal sensor"

>>  	depends on I2C

>> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile

>> index d2cb7e804a0f..3a5ad06d6d89 100644

>> --- a/drivers/hwmon/Makefile

>> +++ b/drivers/hwmon/Makefile

>> @@ -52,6 +52,7 @@ obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o

>>  obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o

>>  obj-$(CONFIG_SENSORS_DELL_SMM)	+= dell-smm-hwmon.o

>>  obj-$(CONFIG_SENSORS_DME1737)	+= dme1737.o

>> +obj-$(CONFIG_SENSORS_DPS310)	+= dps310.o

>>  obj-$(CONFIG_SENSORS_DS620)	+= ds620.o

>>  obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o

>>  obj-$(CONFIG_SENSORS_EMC1403)	+= emc1403.o

>> diff --git a/drivers/hwmon/dps310.c b/drivers/hwmon/dps310.c

>> new file mode 100644

>> index 000000000000..b014f01d0d3f

>> --- /dev/null

>> +++ b/drivers/hwmon/dps310.c

>> @@ -0,0 +1,331 @@

>> +/*

>> + * Copyright 2017 IBM Corporation

>> + *

>> + * Joel Stanley <joel@jms.id.au>

>> + *

>> + * The DPS310 is a barometric pressure and temperature sensor.

>> + *

>> + * This program is free software; you can redistribute it and/or

>> + * modify it under the terms of the GNU General Public License

>> + * as published by the Free Software Foundation; either version

>> + * 2 of the License, or (at your option) any later version.

>> + */

>> +

>> +#include <linux/i2c.h>

>> +#include <linux/regmap.h>

>> +#include <linux/hwmon.h>

>> +#include <linux/module.h>

>> +

>> +#define PRS_B2		0x00

>> +#define PRS_B1		0x01

>> +#define PRS_B0		0x02

>> +#define TMP_B2		0x03

>> +#define TMP_B1		0x04

>> +#define TMP_B0		0x05

>> +#define PRS_CFG		0x06

>> +#define TMP_CFG		0x07

>> +#define  TMP_RATE_BITS	GENMASK(6, 4)

>> +#define  TMP_EXT	BIT(7)

>> +#define MEAS_CFG	0x08

>> +#define  MEAS_CTRL_BITS	GENMASK(2, 0)

>> +#define   PRESSURE_EN	BIT(0)

>> +#define   TEMP_EN	BIT(1)

>> +#define   BACKGROUND	BIT(2)

>> +#define  PRS_RDY	BIT(4)

>> +#define  TMP_RDY	BIT(5)

>> +#define  SENSOR_RDY	BIT(6)

>> +#define  COEF_RDY	BIT(7)

>> +#define RESET		0x0c

>> +#define  RESET_MAGIC	(BIT(0) | BIT(3))

>> +#define COEF_BASE	0x10

>> +

>> +#define TMP_BASE	TMP_B2

>> +#define PRS_BASE	PRS_B2

>> +

>> +#define TMP_RATE(_n)	ilog2(_n)

>> +#define TMP_PRC(_n)	ilog2(_n)

>> +

>> +const int scale_factor[] = {

>> +	 524288,

>> +	1572864,

>> +	3670016,

>> +	7864320,

>> +	 253952,

>> +	 516096,

>> +	1040384,

>> +	2088960,

>> +};

>> +

>> +struct dps310_data {

>> +	struct regmap *regmap;

>> +	int interval;

>> +	s32 c0, c1;

>> +};

>> +

>> +static s32 dps310_twos_compliment(u32 raw, size_t num_bits)

>> +{

>> +	s32 out = raw;

>> +

>> +	if (raw & BIT(num_bits - 1))

>> +		out = raw - BIT(num_bits);

>> +

>> +	return out;

>> +}

>> +

>> +static int dps310_get_temp_coef(struct dps310_data *data)

>> +{

>> +	struct regmap *regmap = data->regmap;

>> +	uint8_t coef[3] = {0};

>> +	int ready, r;

>> +	u32 c0, c1;

>> +

>> +	r = regmap_read(regmap, MEAS_CFG, &ready);

>> +	if (r < 0)

>> +		return r;

>> +

>> +	if (!(ready & COEF_RDY))

>> +		return -EAGAIN;

>> +

>> +	/*

>> +	 * Read temperature calibration coefficients c0 and c1 from the

>> +	 * COEF register. The numbers are 12-bit 2's compliment numbers

>> +	 */

>> +	r = regmap_bulk_read(regmap, COEF_BASE, coef, 3);

>> +	if (r < 0)

>> +		return r;

>> +

>> +	c0 = (coef[0] << 4) | (coef[1] >> 4);

>> +	data->c0 = dps310_twos_compliment(c0, 12);

>> +

>> +	c1 = ((coef[1] & GENMASK(3, 0)) << 8) | coef[2];

>> +	data->c1 = dps310_twos_compliment(c1, 12);

>> +

>> +	return 0;

>> +}

>> +

>> +static int dps310_get_scale_factor(struct device *dev)

>> +{

>> +	struct dps310_data *data = dev_get_drvdata(dev);

>> +	int val, r;

>> +

>> +	r = regmap_read(data->regmap, TMP_CFG, &val);

>> +	if (r < 0)

>> +		return r;

>> +

>> +	/* Scale factor is bottom 4 bits of the register */

>> +	val = val & GENMASK(3, 0);

>> +	if (val < 0 || val > ARRAY_SIZE(scale_factor))

>> +		return -EINVAL;

>> +

>> +	return scale_factor[val];

>> +}

>> +

>> +static int dps310_read_temp(struct device *dev, u32 attr, int channel,

>> +			     long *temp)

>> +{

>> +	struct dps310_data *data = dev_get_drvdata(dev);

>> +	struct regmap *regmap = data->regmap;

>> +	uint8_t val[3] = {0};

>> +	int r, ready;

>> +	int kT, T_raw;

>> +

>> +	switch (attr) {

>> +	case hwmon_temp_input:

>> +		r = regmap_read(regmap, MEAS_CFG, &ready);

>> +		if (r < 0)

>> +			return r;

>> +		if (!(ready & TMP_RDY)) {

>> +			dev_err(dev, "tmp not ready\n");

>> +			return -EAGAIN;

>> +		}

>> +

>> +		/* Choose scaling factor kT based on chosen precision rate */

>> +		kT = dps310_get_scale_factor(dev);

>> +

>> +		r = regmap_bulk_read(regmap, TMP_BASE, val, 3);

>> +		if (r < 0)

>> +			return r;

>> +		T_raw = (val[0] << 16) | (val[1] << 8) | val[2];

>> +		T_raw = dps310_twos_compliment(T_raw, 24);

>> +

>> +		/* (c0 * 0.5 + c1 * T_raw / kT) * 1000 m°C */

>> +		*temp = ((data->c0 >> 1) + (data->c1 * T_raw) / kT) * 1000;

>> +

>> +		return 0;

>> +	default:

>> +		return -EOPNOTSUPP;

>> +	}

>> +}

>> +

>> +static int dps310_read(struct device *dev, enum hwmon_sensor_types type,

>> +			u32 attr, int channel, long *val)

>> +{

>> +	switch (type) {

>> +	case hwmon_temp:

>> +		return dps310_read_temp(dev, attr, channel, val);

>> +	default:

>> +		return -EOPNOTSUPP;

>> +	}

>> +}

>> +

>> +static int dps310_write(struct device *dev, enum hwmon_sensor_types type,

>> +			 u32 attr, int channel, long val)

>> +{

>> +	switch (type) {

>> +	case hwmon_temp:

>> +		/* Fall through */

>> +	default:

>> +		return -EOPNOTSUPP;

>> +	}

>> +}

>> +

>> +static umode_t dps310_is_visible(const void *data,

>> +				  enum hwmon_sensor_types type,

>> +				  u32 attr, int channel)

>> +{

>> +	switch (type) {

>> +	case hwmon_temp:

>> +		switch (attr) {

>> +		case hwmon_temp_input:

>> +			return 0444;

>> +		default:

>> +			return 0;

>> +		}

>> +	default:

>> +		return 0;

>> +	}

>> +}

>> +

>> +

>> +static const u32 dps310_temp_config[] = {

>> +	HWMON_T_INPUT,

>> +	0

>> +};

>> +

>> +static const struct hwmon_channel_info dps310_temp = {

>> +	.type = hwmon_temp,

>> +	.config = dps310_temp_config,

>> +};

>> +

>> +static const struct hwmon_channel_info *dps310_info[] = {

>> +	&dps310_temp,

>> +	NULL

>> +};

>> +

>> +static const struct hwmon_ops dps310_hwmon_ops = {

>> +	.is_visible = dps310_is_visible,

>> +	.read = dps310_read,

>> +	.write = dps310_write,

>> +};

>> +

>> +static const struct hwmon_chip_info dps310_chip_info = {

>> +	.ops = &dps310_hwmon_ops,

>> +	.info = dps310_info,

>> +};

>> +

>> +static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg)

>> +{

>> +	switch (reg) {

>> +	case PRS_CFG:

>> +	case TMP_CFG:

>> +	case MEAS_CFG:

>> +	case RESET:

>> +		return true;

>> +	default:

>> +		return false;

>> +	}

>> +}

>> +

>> +static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg)

>> +{

>> +	switch (reg) {

>> +	case PRS_B2:

>> +	case PRS_B1:

>> +	case PRS_B0:

>> +	case TMP_B2:

>> +	case TMP_B1:

>> +	case TMP_B0:

>> +	case MEAS_CFG:

>> +		return true;

>> +	default:

>> +		return false;

>> +	}

>> +}

>> +

>> +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,

>> +	.use_single_rw = true,

>> +};

>> +

>> +static int dps310_probe(struct i2c_client *client,

>> +			const struct i2c_device_id *id)

>> +{

>> +	struct dps310_data *data;

>> +	struct device *hwmon_dev;

>> +	int r;

>> +

>> +	data = devm_kzalloc(&client->dev,  sizeof(*data), GFP_KERNEL);

>> +	if (!data)

>> +		return -ENOMEM;

>> +

>> +	data->regmap = devm_regmap_init_i2c(client, &dps310_regmap_config);

>> +	if (IS_ERR(data->regmap))

>> +		return PTR_ERR(data->regmap);

>> +

>> +	r = regmap_write(data->regmap, TMP_CFG, TMP_EXT | TMP_PRC(128));

>> +	if (r < 0)

>> +		return r;

>> +

>> +	/* Turn on background temperature measurement */

>> +	r = regmap_update_bits(data->regmap, MEAS_CFG, MEAS_CTRL_BITS,

>> +			TEMP_EN);

>> +	if (r < 0)

>> +		return r;

>> +

>> +	/* Get calibration coefficients required for reporting temperature */

>> +	r = dps310_get_temp_coef(data);

>> +	if (r == -EAGAIN)

>> +		return -EPROBE_DEFER;

>> +	if (r < 0)

>> +		return r;

>> +

>> +	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,

>> +			client->name, data, &dps310_chip_info, NULL);

>> +

>> +	if (IS_ERR(hwmon_dev))

>> +		return PTR_ERR(hwmon_dev);

>> +

>> +	dev_info(&client->dev, "%s: sensor '%s'\n", dev_name(hwmon_dev),

>> +			client->name);

>> +

>> +	return 0;

>> +}

>> +

>> +static const struct i2c_device_id dps310_id[] = {

>> +	{ "dps310", 0 },

>> +	{}

>> +};

>> +MODULE_DEVICE_TABLE(i2c, dps310_id);

>> +

>> +static const unsigned short normal_i2c[] = {

>> +	0x77, 0x76, I2C_CLIENT_END

>> +};

>> +

>> +static struct i2c_driver dps310_driver = {

>> +	.class = I2C_CLASS_HWMON,

>> +	.driver = {

>> +		.name = "dps310",

>> +	},

>> +	.probe = dps310_probe,

>> +	.address_list = normal_i2c,

>> +	.id_table = dps310_id,

>> +};

>> +module_i2c_driver(dps310_driver);

>> +

>> +MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");

>> +MODULE_DESCRIPTION("Infineon DPS310 driver");

>> +MODULE_LICENSE("GPL");

>> -- 

>> 2.11.0

>>

> --

> To unsubscribe from this list: send the line "unsubscribe linux-iio" in

> the body of a message to majordomo@vger.kernel.org

> More majordomo info at  http://vger.kernel.org/majordomo-info.html

>
diff mbox

Patch

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 190d270b20a2..8229b2f8c591 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1349,6 +1349,18 @@  config SENSORS_DME1737
 	  This driver can also be built as a module.  If so, the module
 	  will be called dme1737.
 
+config SENSORS_DPS310
+	tristate "Infineon DPS310"
+	depends on I2C
+	select HWMON_VID
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for the hardware monitoring
+	  features of the Infineon DPS310 digital barometric pressure sensor.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called dps310.
+
 config SENSORS_EMC1403
 	tristate "SMSC EMC1403/23 thermal sensor"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index d2cb7e804a0f..3a5ad06d6d89 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -52,6 +52,7 @@  obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
 obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o
 obj-$(CONFIG_SENSORS_DELL_SMM)	+= dell-smm-hwmon.o
 obj-$(CONFIG_SENSORS_DME1737)	+= dme1737.o
+obj-$(CONFIG_SENSORS_DPS310)	+= dps310.o
 obj-$(CONFIG_SENSORS_DS620)	+= ds620.o
 obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o
 obj-$(CONFIG_SENSORS_EMC1403)	+= emc1403.o
diff --git a/drivers/hwmon/dps310.c b/drivers/hwmon/dps310.c
new file mode 100644
index 000000000000..b014f01d0d3f
--- /dev/null
+++ b/drivers/hwmon/dps310.c
@@ -0,0 +1,331 @@ 
+/*
+ * Copyright 2017 IBM Corporation
+ *
+ * Joel Stanley <joel@jms.id.au>
+ *
+ * The DPS310 is a barometric pressure and temperature sensor.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/hwmon.h>
+#include <linux/module.h>
+
+#define PRS_B2		0x00
+#define PRS_B1		0x01
+#define PRS_B0		0x02
+#define TMP_B2		0x03
+#define TMP_B1		0x04
+#define TMP_B0		0x05
+#define PRS_CFG		0x06
+#define TMP_CFG		0x07
+#define  TMP_RATE_BITS	GENMASK(6, 4)
+#define  TMP_EXT	BIT(7)
+#define MEAS_CFG	0x08
+#define  MEAS_CTRL_BITS	GENMASK(2, 0)
+#define   PRESSURE_EN	BIT(0)
+#define   TEMP_EN	BIT(1)
+#define   BACKGROUND	BIT(2)
+#define  PRS_RDY	BIT(4)
+#define  TMP_RDY	BIT(5)
+#define  SENSOR_RDY	BIT(6)
+#define  COEF_RDY	BIT(7)
+#define RESET		0x0c
+#define  RESET_MAGIC	(BIT(0) | BIT(3))
+#define COEF_BASE	0x10
+
+#define TMP_BASE	TMP_B2
+#define PRS_BASE	PRS_B2
+
+#define TMP_RATE(_n)	ilog2(_n)
+#define TMP_PRC(_n)	ilog2(_n)
+
+const int scale_factor[] = {
+	 524288,
+	1572864,
+	3670016,
+	7864320,
+	 253952,
+	 516096,
+	1040384,
+	2088960,
+};
+
+struct dps310_data {
+	struct regmap *regmap;
+	int interval;
+	s32 c0, c1;
+};
+
+static s32 dps310_twos_compliment(u32 raw, size_t num_bits)
+{
+	s32 out = raw;
+
+	if (raw & BIT(num_bits - 1))
+		out = raw - BIT(num_bits);
+
+	return out;
+}
+
+static int dps310_get_temp_coef(struct dps310_data *data)
+{
+	struct regmap *regmap = data->regmap;
+	uint8_t coef[3] = {0};
+	int ready, r;
+	u32 c0, c1;
+
+	r = regmap_read(regmap, MEAS_CFG, &ready);
+	if (r < 0)
+		return r;
+
+	if (!(ready & COEF_RDY))
+		return -EAGAIN;
+
+	/*
+	 * Read temperature calibration coefficients c0 and c1 from the
+	 * COEF register. The numbers are 12-bit 2's compliment numbers
+	 */
+	r = regmap_bulk_read(regmap, COEF_BASE, coef, 3);
+	if (r < 0)
+		return r;
+
+	c0 = (coef[0] << 4) | (coef[1] >> 4);
+	data->c0 = dps310_twos_compliment(c0, 12);
+
+	c1 = ((coef[1] & GENMASK(3, 0)) << 8) | coef[2];
+	data->c1 = dps310_twos_compliment(c1, 12);
+
+	return 0;
+}
+
+static int dps310_get_scale_factor(struct device *dev)
+{
+	struct dps310_data *data = dev_get_drvdata(dev);
+	int val, r;
+
+	r = regmap_read(data->regmap, TMP_CFG, &val);
+	if (r < 0)
+		return r;
+
+	/* Scale factor is bottom 4 bits of the register */
+	val = val & GENMASK(3, 0);
+	if (val < 0 || val > ARRAY_SIZE(scale_factor))
+		return -EINVAL;
+
+	return scale_factor[val];
+}
+
+static int dps310_read_temp(struct device *dev, u32 attr, int channel,
+			     long *temp)
+{
+	struct dps310_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
+	uint8_t val[3] = {0};
+	int r, ready;
+	int kT, T_raw;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		r = regmap_read(regmap, MEAS_CFG, &ready);
+		if (r < 0)
+			return r;
+		if (!(ready & TMP_RDY)) {
+			dev_err(dev, "tmp not ready\n");
+			return -EAGAIN;
+		}
+
+		/* Choose scaling factor kT based on chosen precision rate */
+		kT = dps310_get_scale_factor(dev);
+
+		r = regmap_bulk_read(regmap, TMP_BASE, val, 3);
+		if (r < 0)
+			return r;
+		T_raw = (val[0] << 16) | (val[1] << 8) | val[2];
+		T_raw = dps310_twos_compliment(T_raw, 24);
+
+		/* (c0 * 0.5 + c1 * T_raw / kT) * 1000 m°C */
+		*temp = ((data->c0 >> 1) + (data->c1 * T_raw) / kT) * 1000;
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int dps310_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_temp:
+		return dps310_read_temp(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int dps310_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_temp:
+		/* Fall through */
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t dps310_is_visible(const void *data,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+			return 0444;
+		default:
+			return 0;
+		}
+	default:
+		return 0;
+	}
+}
+
+
+static const u32 dps310_temp_config[] = {
+	HWMON_T_INPUT,
+	0
+};
+
+static const struct hwmon_channel_info dps310_temp = {
+	.type = hwmon_temp,
+	.config = dps310_temp_config,
+};
+
+static const struct hwmon_channel_info *dps310_info[] = {
+	&dps310_temp,
+	NULL
+};
+
+static const struct hwmon_ops dps310_hwmon_ops = {
+	.is_visible = dps310_is_visible,
+	.read = dps310_read,
+	.write = dps310_write,
+};
+
+static const struct hwmon_chip_info dps310_chip_info = {
+	.ops = &dps310_hwmon_ops,
+	.info = dps310_info,
+};
+
+static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case PRS_CFG:
+	case TMP_CFG:
+	case MEAS_CFG:
+	case RESET:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case PRS_B2:
+	case PRS_B1:
+	case PRS_B0:
+	case TMP_B2:
+	case TMP_B1:
+	case TMP_B0:
+	case MEAS_CFG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+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,
+	.use_single_rw = true,
+};
+
+static int dps310_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct dps310_data *data;
+	struct device *hwmon_dev;
+	int r;
+
+	data = devm_kzalloc(&client->dev,  sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = devm_regmap_init_i2c(client, &dps310_regmap_config);
+	if (IS_ERR(data->regmap))
+		return PTR_ERR(data->regmap);
+
+	r = regmap_write(data->regmap, TMP_CFG, TMP_EXT | TMP_PRC(128));
+	if (r < 0)
+		return r;
+
+	/* Turn on background temperature measurement */
+	r = regmap_update_bits(data->regmap, MEAS_CFG, MEAS_CTRL_BITS,
+			TEMP_EN);
+	if (r < 0)
+		return r;
+
+	/* Get calibration coefficients required for reporting temperature */
+	r = dps310_get_temp_coef(data);
+	if (r == -EAGAIN)
+		return -EPROBE_DEFER;
+	if (r < 0)
+		return r;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
+			client->name, data, &dps310_chip_info, NULL);
+
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	dev_info(&client->dev, "%s: sensor '%s'\n", dev_name(hwmon_dev),
+			client->name);
+
+	return 0;
+}
+
+static const struct i2c_device_id dps310_id[] = {
+	{ "dps310", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, dps310_id);
+
+static const unsigned short normal_i2c[] = {
+	0x77, 0x76, I2C_CLIENT_END
+};
+
+static struct i2c_driver dps310_driver = {
+	.class = I2C_CLASS_HWMON,
+	.driver = {
+		.name = "dps310",
+	},
+	.probe = dps310_probe,
+	.address_list = normal_i2c,
+	.id_table = dps310_id,
+};
+module_i2c_driver(dps310_driver);
+
+MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
+MODULE_DESCRIPTION("Infineon DPS310 driver");
+MODULE_LICENSE("GPL");