RE: [PATCH v4 1/3] iio: pressure: Add driver for DLH pressure sensors

["Denis, Tomislav AVL DiTEST" <Tomislav.Denis@avl.com>]

> On Wed, 11 Dec 2019 10:59:44 +0100
> <tomislav.denis@avl.com> wrote:
> 
> > From: Tomislav Denis <tomislav.denis@avl.com>
> >
> > All Sensors DLH is series of low voltage digital pressure sensors.
> > Additionally to pressure value sensors deliver a temperature value.
> > Sensors can be accessed over I2C and SPI, this driver supports only
> > I2C access.
> >
> > Signed-off-by: Tomislav Denis <tomislav.denis@avl.com>
> 
> Gah. My explanation on the wildcard naming thing was not clear before.
> Sorry about that.  What I meant was this needs to have an explicit
> name after a single part number.   I've renamed
> as dlhl60d.c and all similar places.
> I left the define prefix as DLH_ as unlikely we'll get any problems with that.
> 
> Applied to the togreg branch of iio.git and pushed out as testing for the
> autobuilders to see if they can break it.
> 
> Thanks,
> 
> Jonathan
> 

Hi Jonathan,

Ok great. Thanks a lot for helping me with this, I've learned a lot from you.

Tomislav

> > ---
> >  MAINTAINERS                   |   7 +
> >  drivers/iio/pressure/Kconfig  |  12 ++
> >  drivers/iio/pressure/Makefile |   1 +
> >  drivers/iio/pressure/dlh.c    | 375
> ++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 395 insertions(+)
> >  create mode 100644 drivers/iio/pressure/dlh.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index d5ea4e4..0fa24df 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -668,6 +668,13 @@ S:	Maintained
> >  F:	Documentation/i2c/busses/i2c-ali1563.rst
> >  F:	drivers/i2c/busses/i2c-ali1563.c
> >
> > +ALL SENSORS DLH SERIES PRESSURE SENSORS DRIVER
> > +M:	Tomislav Denis <tomislav.denis@avl.com>
> > +W:	http://www.allsensors.com/
> > +S:	Maintained
> > +L:	linux-iio@vger.kernel.org
> > +F:	drivers/iio/pressure/dlh.c
> > +
> >  ALLEGRO DVT VIDEO IP CORE DRIVER
> >  M:	Michael Tretter <m.tretter@pengutronix.de>
> >  R:	Pengutronix Kernel Team <kernel@pengutronix.de>
> > diff --git a/drivers/iio/pressure/Kconfig
> > b/drivers/iio/pressure/Kconfig index ba420e4..3d383d8 100644
> > --- a/drivers/iio/pressure/Kconfig
> > +++ b/drivers/iio/pressure/Kconfig
> > @@ -53,6 +53,18 @@ config IIO_CROS_EC_BARO
> >  	  To compile this driver as a module, choose M here: the module
> >  	  will be called cros_ec_baro.
> >
> > +config DLH
> > +	tristate "All Sensors DLH series low voltage digital pressure sensors"
> > +	depends on I2C
> > +	select IIO_BUFFER
> > +	select IIO_TRIGGERED_BUFFER
> > +	help
> > +	  Say yes here to build support for the All Sensors DLH series
> > +	  pressure sensors driver.
> > +
> > +	  To compile this driver as a module, choose M here: the module
> > +	  will be called dlh.
> > +
> >  config DPS310
> >  	tristate "Infineon DPS310 pressure and temperature sensor"
> >  	depends on I2C
> > diff --git a/drivers/iio/pressure/Makefile
> > b/drivers/iio/pressure/Makefile index d8f5ace..c609ad4 100644
> > --- a/drivers/iio/pressure/Makefile
> > +++ b/drivers/iio/pressure/Makefile
> > @@ -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_DLH) += dlh.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
> > diff --git a/drivers/iio/pressure/dlh.c b/drivers/iio/pressure/dlh.c
> > new file mode 100644 index 0000000..18fc4e1
> > --- /dev/null
> > +++ b/drivers/iio/pressure/dlh.c
> > @@ -0,0 +1,375 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * All Sensors DLH series low voltage digital pressure sensors
> > + *
> > + * Copyright (c) 2019 AVL DiTEST GmbH
> > + *   Tomislav Denis <tomislav.denis@avl.com>
> > + *
> > + * Datasheet: http://www.allsensors.com/cad/DS-0355_Rev_B.PDF
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/iio/buffer.h>
> > +#include <linux/iio/trigger_consumer.h> #include
> > +<linux/iio/triggered_buffer.h> #include <asm/unaligned.h>
> > +
> > +/* Commands */
> > +#define DLH_START_SINGLE    0xAA
> > +
> > +/* Status bits */
> > +#define DLH_STATUS_OK       0x40
> > +
> > +/* DLH  data format */
> > +#define DLH_NUM_READ_BYTES  7
> > +#define DLH_NUM_DATA_BYTES  3
> > +#define DLH_NUM_PR_BITS     24
> > +#define DLH_NUM_TEMP_BITS   24
> > +
> > +/* DLH  timings */
> > +#define DLH_SINGLE_DUT_MS   5
> > +
> > +enum dhl_ids {
> > +	dlhl60d,
> > +	dlhl60g,
> > +};
> > +
> > +struct dlh_info {
> > +	u8 osdig;           /* digital offset factor */
> > +	unsigned int fss;   /* full scale span (inch H2O) */
> > +};
> > +
> > +struct dlh_state {
> > +	struct i2c_client *client;
> > +	struct dlh_info info;
> > +	bool use_interrupt;
> > +	struct completion completion;
> > +	u8 rx_buf[DLH_NUM_READ_BYTES] ____cacheline_aligned; };
> > +
> > +static struct dlh_info dlh_info_tbl[] = {
> > +	[dlhl60d] = {
> > +		.osdig = 2,
> > +		.fss = 120,
> > +	},
> > +	[dlhl60g] = {
> > +		.osdig = 10,
> > +		.fss = 60,
> > +	},
> > +};
> > +
> > +
> > +static int dlh_cmd_start_single(struct dlh_state *st) {
> > +	int ret;
> > +
> > +	ret = i2c_smbus_write_byte(st->client, DLH_START_SINGLE);
> > +	if (ret)
> > +		dev_err(&st->client->dev,
> > +			"%s: I2C write byte failed\n", __func__);
> > +
> > +	return ret;
> > +}
> > +
> > +static int dlh_cmd_read_data(struct dlh_state *st) {
> > +	int ret;
> > +
> > +	ret = i2c_master_recv(st->client, st->rx_buf,
> DLH_NUM_READ_BYTES);
> > +	if (ret < 0) {
> > +		dev_err(&st->client->dev,
> > +			"%s: I2C read block failed\n", __func__);
> > +		return ret;
> > +	}
> > +
> > +	if (st->rx_buf[0] != DLH_STATUS_OK) {
> > +		dev_err(&st->client->dev,
> > +			"%s: invalid status 0x%02x\n", __func__, st-
> >rx_buf[0]);
> > +		return -EBUSY;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int dlh_start_capture_and_read(struct dlh_state *st) {
> > +	int ret;
> > +
> > +	if (st->use_interrupt)
> > +		reinit_completion(&st->completion);
> > +
> > +	ret = dlh_cmd_start_single(st);
> > +	if (ret)
> > +		return ret;
> > +
> > +	if (st->use_interrupt) {
> > +		ret = wait_for_completion_timeout(&st->completion,
> > +			msecs_to_jiffies(DLH_SINGLE_DUT_MS));
> > +		if (!ret) {
> > +			dev_err(&st->client->dev,
> > +				"%s: conversion timed out\n", __func__);
> > +			return -ETIMEDOUT;
> > +		}
> > +	} else {
> > +		mdelay(DLH_SINGLE_DUT_MS);
> > +	}
> > +
> > +	return dlh_cmd_read_data(st);
> > +}
> > +
> > +static int dlh_read_direct(struct dlh_state *st,
> > +	unsigned int *pressure, unsigned int *temperature) {
> > +	int ret;
> > +
> > +	ret = dlh_start_capture_and_read(st);
> > +	if (ret)
> > +		return ret;
> > +
> > +	*pressure = get_unaligned_be32(&st->rx_buf[1]) >> 8;
> > +	*temperature = get_unaligned_be32(&st->rx_buf[3]) &
> > +		GENMASK(DLH_NUM_TEMP_BITS - 1, 0);
> > +
> > +	return 0;
> > +}
> > +
> > +static int dlh_read_raw(struct iio_dev *indio_dev,
> > +	struct iio_chan_spec const *channel, int *value,
> > +	int *value2, long mask)
> > +{
> > +	struct dlh_state *st = iio_priv(indio_dev);
> > +	unsigned int pressure, temperature;
> > +	int ret;
> > +	s64 tmp;
> > +	s32 rem;
> > +
> > +	switch (mask) {
> > +	case IIO_CHAN_INFO_RAW:
> > +		ret = iio_device_claim_direct_mode(indio_dev);
> > +		if (ret)
> > +			return ret;
> > +
> > +		ret = dlh_read_direct(st, &pressure, &temperature);
> > +		iio_device_release_direct_mode(indio_dev);
> > +		if (ret)
> > +			return ret;
> > +
> > +		switch (channel->type) {
> > +		case IIO_PRESSURE:
> > +			*value = pressure;
> > +			return IIO_VAL_INT;
> > +
> > +		case IIO_TEMP:
> > +			*value = temperature;
> > +			return IIO_VAL_INT;
> > +
> > +		default:
> > +			return -EINVAL;
> > +		}
> > +	case IIO_CHAN_INFO_SCALE:
> > +		switch (channel->type) {
> > +		case IIO_PRESSURE:
> > +			tmp = div_s64(125LL * st->info.fss * 24909 * 100,
> > +				1 << DLH_NUM_PR_BITS);
> > +			tmp = div_s64_rem(tmp, 1000000000LL, &rem);
> > +			*value = tmp;
> > +			*value2 = rem;
> > +			return IIO_VAL_INT_PLUS_NANO;
> > +
> > +		case IIO_TEMP:
> > +			*value = 125 * 1000;
> > +			*value2 = DLH_NUM_TEMP_BITS;
> > +			return IIO_VAL_FRACTIONAL_LOG2;
> > +
> > +		default:
> > +			return -EINVAL;
> > +		}
> > +	case IIO_CHAN_INFO_OFFSET:
> > +		switch (channel->type) {
> > +		case IIO_PRESSURE:
> > +			*value = -125 * st->info.fss * 24909;
> > +			*value2 = 100 * st->info.osdig * 100000;
> > +			return IIO_VAL_FRACTIONAL;
> > +
> > +		case IIO_TEMP:
> > +			*value = -40 * 1000;
> > +			return IIO_VAL_INT;
> > +
> > +		default:
> > +			return -EINVAL;
> > +		}
> > +	}
> > +
> > +	return -EINVAL;
> > +}
> > +
> > +static const struct iio_info dlh_info = {
> > +	.read_raw = dlh_read_raw,
> > +};
> > +
> > +static const struct iio_chan_spec dlh_channels[] = {
> > +	{
> > +		.type = IIO_PRESSURE,
> > +		.indexed = 1,
> > +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > +		.info_mask_shared_by_type =
> > +			BIT(IIO_CHAN_INFO_SCALE) |
> > +			BIT(IIO_CHAN_INFO_OFFSET),
> > +		.scan_index = 0,
> > +		.scan_type = {
> > +			.sign = 'u',
> > +			.realbits = DLH_NUM_PR_BITS,
> > +			.storagebits = 32,
> > +			.shift = 8,
> > +			.endianness = IIO_BE,
> > +		},
> > +	}, {
> > +		.type = IIO_TEMP,
> > +		.indexed = 1,
> > +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > +		.info_mask_shared_by_type =
> > +			BIT(IIO_CHAN_INFO_SCALE) |
> > +			BIT(IIO_CHAN_INFO_OFFSET),
> > +		.scan_index = 1,
> > +		.scan_type = {
> > +			.sign = 'u',
> > +			.realbits = DLH_NUM_TEMP_BITS,
> > +			.storagebits = 32,
> > +			.shift = 8,
> > +			.endianness = IIO_BE,
> > +		},
> > +	}
> > +};
> > +
> > +static irqreturn_t dlh_trigger_handler(int irq, void *private) {
> > +	struct iio_poll_func *pf = private;
> > +	struct iio_dev *indio_dev = pf->indio_dev;
> > +	struct dlh_state *st = iio_priv(indio_dev);
> > +	int ret;
> > +	unsigned int chn, i = 0;
> > +	__be32 tmp_buf[2];
> > +
> > +	ret = dlh_start_capture_and_read(st);
> > +	if (ret)
> > +		goto out;
> > +
> > +	for_each_set_bit(chn, indio_dev->active_scan_mask,
> > +		indio_dev->masklength) {
> > +		memcpy(tmp_buf + i,
> > +			&st->rx_buf[1] + chn * DLH_NUM_DATA_BYTES,
> > +			DLH_NUM_DATA_BYTES);
> > +		i++;
> > +	}
> > +
> > +	iio_push_to_buffers(indio_dev, tmp_buf);
> > +
> > +out:
> > +	iio_trigger_notify_done(indio_dev->trig);
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static irqreturn_t dlh_interrupt(int irq, void *private) {
> > +	struct iio_dev *indio_dev = private;
> > +	struct dlh_state *st = iio_priv(indio_dev);
> > +
> > +	complete(&st->completion);
> > +
> > +	return IRQ_HANDLED;
> > +};
> > +
> > +static int dlh_probe(struct i2c_client *client,
> > +	const struct i2c_device_id *id)
> > +{
> > +	struct dlh_state *st;
> > +	struct iio_dev *indio_dev;
> > +	int ret;
> > +
> > +	if (!i2c_check_functionality(client->adapter,
> > +		I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE)) {
> > +		dev_err(&client->dev,
> > +			"adapter doesn't support required i2c
> functionality\n");
> > +		return -EOPNOTSUPP;
> > +	}
> > +
> > +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
> > +	if (!indio_dev) {
> > +		dev_err(&client->dev, "failed to allocate iio device\n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	i2c_set_clientdata(client, indio_dev);
> > +
> > +	st = iio_priv(indio_dev);
> > +	st->info = dlh_info_tbl[id->driver_data];
> > +	st->client = client;
> > +	st->use_interrupt = false;
> > +
> > +	indio_dev->name = id->name;
> > +	indio_dev->dev.parent = &client->dev;
> > +	indio_dev->dev.of_node = client->dev.of_node;
> > +	indio_dev->info = &dlh_info;
> > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > +	indio_dev->channels =  dlh_channels;
> > +	indio_dev->num_channels = ARRAY_SIZE(dlh_channels);
> > +
> > +	if (client->irq > 0) {
> > +		ret = devm_request_threaded_irq(&client->dev, client->irq,
> > +			dlh_interrupt, NULL,
> > +			IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> > +			id->name, indio_dev);
> > +		if (ret) {
> > +			dev_err(&client->dev, "failed to allocate threaded
> irq");
> > +			return ret;
> > +		}
> > +
> > +		st->use_interrupt = true;
> > +		init_completion(&st->completion);
> > +	}
> > +
> > +	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
> > +		NULL, &dlh_trigger_handler, NULL);
> > +	if (ret) {
> > +		dev_err(&client->dev, "failed to setup iio buffer\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = devm_iio_device_register(&client->dev, indio_dev);
> > +	if (ret)
> > +		dev_err(&client->dev, "failed to register iio device\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static const struct of_device_id dlh_of_match[] = {
> > +	{ .compatible = "asc,dlhl60d" },
> > +	{ .compatible = "asc,dlhl60g" },
> > +	{}
> > +};
> > +MODULE_DEVICE_TABLE(of, dlh_of_match);
> > +
> > +static const struct i2c_device_id dlh_id[] = {
> > +	{ "dlhl60d",    dlhl60d },
> > +	{ "dlhl60g",    dlhl60g },
> > +	{}
> > +};
> > +MODULE_DEVICE_TABLE(i2c, dlh_id);
> > +
> > +static struct i2c_driver dlh_driver = {
> > +	.driver = {
> > +		.name = "dlh",
> > +		.of_match_table = dlh_of_match,
> > +	},
> > +	.probe = dlh_probe,
> > +	.id_table = dlh_id,
> > +};
> > +module_i2c_driver(dlh_driver);
> > +
> > +MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
> > +MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure
> > +sensors"); MODULE_LICENSE("GPL v2");