Re: [PATCH v3 1/3] iio: pressure: Add driver for DLH pressure sensors

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 4 Dec 2019 11:03:52 +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>
Ah. Sorry I missed this before, but the -i2c part of the filename is effectively
a wild card. Given we can't know what parts asc will release in the future
that will be incompatible we should avoid generic naming and just pick a
supported part.

Given you are respinning anyway a few things inline I might just have fixed
up whilst applying otherwise.

Thanks,

Jonathan


> ---
>  MAINTAINERS                    |   7 +
>  drivers/iio/pressure/Kconfig   |  12 ++
>  drivers/iio/pressure/Makefile  |   1 +
>  drivers/iio/pressure/dlh-i2c.c | 375 +++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 395 insertions(+)
>  create mode 100644 drivers/iio/pressure/dlh-i2c.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d5ea4e4..39d6f0f 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-i2c.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..504de3e 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_I2C
> +	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-i2c.
> +
>  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..1851a36 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_I2C) += dlh-i2c.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-i2c.c b/drivers/iio/pressure/dlh-i2c.c
> new file mode 100644
> index 0000000..b8491a8
> --- /dev/null
> +++ b/drivers/iio/pressure/dlh-i2c.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.h>
This trigger.h header should only need to be included in drivers that create
a trigger, hence shouldn't be included here.

> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.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_i2c_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_i2c_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_i2c_start_capture_and_read(struct dlh_state *st)
> +{
> +	int ret;
> +
> +	if (st->use_interrupt)
> +		reinit_completion(&st->completion);
> +
> +	ret = dlh_i2c_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_i2c_cmd_read_data(st);
> +}
> +
> +static int dlh_i2c_read_direct(struct dlh_state *st,
> +	unsigned int *pressure, unsigned int *temperature)
> +{
> +	int ret;
> +
> +	ret = dlh_i2c_start_capture_and_read(st);
> +	if (ret)
> +		return ret;
> +
> +	*pressure = be32_to_cpup((u32 *)&st->rx_buf[1]) >> 8;

Odd casting here.  You are casting to a cpu endian u32 and then
claiming it's big endian.  (__be32 *)



> +	*temperature = be32_to_cpup((u32 *)&st->rx_buf[3]) &
> +		GENMASK(DLH_NUM_TEMP_BITS - 1, 0);
> +
> +	return 0;
> +}
> +
> +static int dlh_i2c_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_i2c_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_i2c_info = {
> +	.read_raw = dlh_i2c_read_raw,
> +};
> +
> +static const struct iio_chan_spec dlh_i2c_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_i2c_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_i2c_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_i2c_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_i2c_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_i2c_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels =  dlh_i2c_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(dlh_i2c_channels);
> +
> +	if (client->irq > 0) {
> +		ret = devm_request_threaded_irq(&client->dev, client->irq,
> +			dlh_i2c_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_i2c_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_i2c_of_match[] = {
> +	{ .compatible = "asc,dlhl60d" },
> +	{ .compatible = "asc,dlhl60g" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, dlh_i2c_of_match);
> +
> +static const struct i2c_device_id dlh_i2c_id[] = {
> +	{ "dlhl60d",    dlhl60d },
> +	{ "dlhl60g",    dlhl60g },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, dlh_i2c_id);
> +
> +static struct i2c_driver dlh_i2c_driver = {
> +	.driver = {
> +		.name = "dlh_i2c",
> +		.of_match_table = dlh_i2c_of_match,
> +	},
> +	.probe = dlh_i2c_probe,
> +	.id_table = dlh_i2c_id,
> +};
> +module_i2c_driver(dlh_i2c_driver);
> +
> +MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
> +MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure sensors");
> +MODULE_LICENSE("GPL v2");