[PATCH v4 0/3] add support for PMS7003 PM sensor

[PATCH v4 0/3] add support for PMS7003 PM sensor

[Tomasz Duszynski]

This patch series adds support for Plantower PMS7003 PM matter sensor.

Unfortunately datasheet is not available for download from the Plantower
website so one needs to find it elsewhere, for instance here:

https://download.kamami.com/p564008-p564008-PMS7003%20series%20data%20manua_English_V2.5.pdf

v4:
 * add vendor prefix to set-gpios property

v3:
 * fix whitespaces
 * drop unused printk format specifier
 * make vcc-supply mandatory in dt binding
 * use a generic node name (air-pollution-sensor) instead of a sensor model

v2:
 * check number of bytes returned from serdev_device_write()
   (due to changes in linux 5.0 serdev api)
 * add missing pins descriptions to the driver binding
 * keep commands in the lookup table
 * buffer data and process everything in one go instead of using state machine
 * keep pm offset in channel address to simplify reading measurements

Tomasz Duszynski (3):
  iio: chemical: add support for Plantower PMS7003 sensor
  dt-bindings: add Plantower to the vendor prefixes
  dt-bindings: iio: chemical: pms7003: add device tree support

 .../iio/chemical/plantower,pms7003.txt        |  20 ++
 .../devicetree/bindings/vendor-prefixes.txt   |   1 +
 drivers/iio/chemical/Kconfig                  |  10 +
 drivers/iio/chemical/Makefile                 |   1 +
 drivers/iio/chemical/pms7003.c                | 340 ++++++++++++++++++
 5 files changed, 372 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt
 create mode 100644 drivers/iio/chemical/pms7003.c

--
2.20.1

[PATCH v4 1/3] iio: chemical: add support for Plantower PMS7003 sensor

[Tomasz Duszynski]

Add support for Plantower PMS7003 particulate matter sensor.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
---
 drivers/iio/chemical/Kconfig   |  10 +
 drivers/iio/chemical/Makefile  |   1 +
 drivers/iio/chemical/pms7003.c | 340 +++++++++++++++++++++++++++++++++
 3 files changed, 351 insertions(+)
 create mode 100644 drivers/iio/chemical/pms7003.c

diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
index 57832b4360e9..d5d146e9e372 100644
--- a/drivers/iio/chemical/Kconfig
+++ b/drivers/iio/chemical/Kconfig
@@ -61,6 +61,16 @@ config IAQCORE
 	  iAQ-Core Continuous/Pulsed VOC (Volatile Organic Compounds)
 	  sensors
 
+config PMS7003
+	tristate "Plantower PMS7003 particulate matter sensor"
+	depends on SERIAL_DEV_BUS
+	help
+	  Say Y here to build support for the Plantower PMS7003 particulate
+	  matter sensor.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called pms7003.
+
 config SPS30
 	tristate "SPS30 particulate matter sensor"
 	depends on I2C
diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
index 65bf0f89c0e4..f5d1365acb49 100644
--- a/drivers/iio/chemical/Makefile
+++ b/drivers/iio/chemical/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_BME680_I2C) += bme680_i2c.o
 obj-$(CONFIG_BME680_SPI) += bme680_spi.o
 obj-$(CONFIG_CCS811)		+= ccs811.o
 obj-$(CONFIG_IAQCORE)		+= ams-iaq-core.o
+obj-$(CONFIG_PMS7003) += pms7003.o
 obj-$(CONFIG_SENSIRION_SGP30)	+= sgp30.o
 obj-$(CONFIG_SPS30) += sps30.o
 obj-$(CONFIG_VZ89X)		+= vz89x.o
diff --git a/drivers/iio/chemical/pms7003.c b/drivers/iio/chemical/pms7003.c
new file mode 100644
index 000000000000..0c913c60adde
--- /dev/null
+++ b/drivers/iio/chemical/pms7003.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Plantower PMS7003 particulate matter sensor driver
+ *
+ * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
+ */
+
+#include <asm/unaligned.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/serdev.h>
+
+#define PMS7003_DRIVER_NAME "pms7003"
+
+#define PMS7003_MAGIC 0x424d
+/* last 2 data bytes hold frame checksum */
+#define PMS7003_MAX_DATA_LENGTH 28
+#define PMS7003_CHECKSUM_LENGTH 2
+#define PMS7003_PM10_OFFSET 10
+#define PMS7003_PM2P5_OFFSET 8
+#define PMS7003_PM1_OFFSET 6
+
+#define PMS7003_TIMEOUT msecs_to_jiffies(6000)
+#define PMS7003_CMD_LENGTH 7
+#define PMS7003_PM_MAX 1000
+#define PMS7003_PM_MIN 0
+
+enum {
+	PM1,
+	PM2P5,
+	PM10,
+};
+
+enum pms7003_cmd {
+	CMD_WAKEUP,
+	CMD_ENTER_PASSIVE_MODE,
+	CMD_READ_PASSIVE,
+	CMD_SLEEP,
+};
+
+/*
+ * commands have following format:
+ *
+ * +------+------+-----+------+-----+-----------+-----------+
+ * | 0x42 | 0x4d | cmd | 0x00 | arg | cksum msb | cksum lsb |
+ * +------+------+-----+------+-----+-----------+-----------+
+ */
+static const u8 pms7003_cmd_tbl[][PMS7003_CMD_LENGTH] = {
+	[CMD_WAKEUP] = { 0x42, 0x4d, 0xe4, 0x00, 0x01, 0x01, 0x74 },
+	[CMD_ENTER_PASSIVE_MODE] = { 0x42, 0x4d, 0xe1, 0x00, 0x00, 0x01, 0x70 },
+	[CMD_READ_PASSIVE] = { 0x42, 0x4d, 0xe2, 0x00, 0x00, 0x01, 0x71 },
+	[CMD_SLEEP] = { 0x42, 0x4d, 0xe4, 0x00, 0x00, 0x01, 0x73 },
+};
+
+struct pms7003_frame {
+	u8 data[PMS7003_MAX_DATA_LENGTH];
+	u16 expected_length;
+	u16 length;
+};
+
+struct pms7003_state {
+	struct serdev_device *serdev;
+	struct pms7003_frame frame;
+	struct completion frame_ready;
+	struct mutex lock; /* must be held whenever state gets touched */
+};
+
+static int pms7003_do_cmd(struct pms7003_state *state, enum pms7003_cmd cmd)
+{
+	int ret;
+
+	ret = serdev_device_write(state->serdev, pms7003_cmd_tbl[cmd],
+				  PMS7003_CMD_LENGTH, PMS7003_TIMEOUT);
+	if (ret < PMS7003_CMD_LENGTH)
+		return ret < 0 ? ret : -EIO;
+
+	ret = wait_for_completion_interruptible_timeout(&state->frame_ready,
+							PMS7003_TIMEOUT);
+	if (!ret)
+		ret = -ETIMEDOUT;
+
+	return ret < 0 ? ret : 0;
+}
+
+static u16 pms7003_get_pm(const u8 *data)
+{
+	return clamp_val(get_unaligned_be16(data),
+			 PMS7003_PM_MIN, PMS7003_PM_MAX);
+}
+
+static irqreturn_t pms7003_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct pms7003_state *state = iio_priv(indio_dev);
+	struct pms7003_frame *frame = &state->frame;
+	u16 data[3 + 1 + 4]; /* PM1, PM2P5, PM10, padding, timestamp */
+	int ret;
+
+	mutex_lock(&state->lock);
+	ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
+	if (ret) {
+		mutex_unlock(&state->lock);
+		goto err;
+	}
+
+	data[PM1] = pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET);
+	data[PM2P5] = pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET);
+	data[PM10] = pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET);
+	mutex_unlock(&state->lock);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data,
+					   iio_get_time_ns(indio_dev));
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int pms7003_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct pms7003_state *state = iio_priv(indio_dev);
+	struct pms7003_frame *frame = &state->frame;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		switch (chan->type) {
+		case IIO_MASSCONCENTRATION:
+			mutex_lock(&state->lock);
+			ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
+			if (ret) {
+				mutex_unlock(&state->lock);
+				return ret;
+			}
+
+			*val = pms7003_get_pm(frame->data + chan->address);
+			mutex_unlock(&state->lock);
+
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info pms7003_info = {
+	.read_raw = pms7003_read_raw,
+};
+
+#define PMS7003_CHAN(_index, _mod, _addr) { \
+	.type = IIO_MASSCONCENTRATION, \
+	.modified = 1, \
+	.channel2 = IIO_MOD_ ## _mod, \
+	.address = _addr, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
+	.scan_index = _index, \
+	.scan_type = { \
+		.sign = 'u', \
+		.realbits = 10, \
+		.storagebits = 16, \
+		.endianness = IIO_CPU, \
+	}, \
+}
+
+static const struct iio_chan_spec pms7003_channels[] = {
+	PMS7003_CHAN(0, PM1, PMS7003_PM1_OFFSET),
+	PMS7003_CHAN(1, PM2P5, PMS7003_PM2P5_OFFSET),
+	PMS7003_CHAN(2, PM10, PMS7003_PM10_OFFSET),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static u16 pms7003_calc_checksum(struct pms7003_frame *frame)
+{
+	u16 checksum = (PMS7003_MAGIC >> 8) + (u8)PMS7003_MAGIC +
+		       (frame->length >> 8) + (u8)frame->length;
+	int i;
+
+	for (i = 0; i < frame->length - PMS7003_CHECKSUM_LENGTH; i++)
+		checksum += frame->data[i];
+
+	return checksum;
+}
+
+static bool pms7003_frame_is_okay(struct pms7003_frame *frame)
+{
+	int offset = frame->length - PMS7003_CHECKSUM_LENGTH;
+	u16 checksum = get_unaligned_be16(frame->data + offset);
+
+	return checksum == pms7003_calc_checksum(frame);
+}
+
+static int pms7003_receive_buf(struct serdev_device *serdev,
+			       const unsigned char *buf, size_t size)
+{
+	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
+	struct pms7003_state *state = iio_priv(indio_dev);
+	struct pms7003_frame *frame = &state->frame;
+	int num;
+
+	if (!frame->expected_length) {
+		u16 magic;
+
+		/* wait for SOF and data length */
+		if (size < 4)
+			return 0;
+
+		magic = get_unaligned_be16(buf);
+		if (magic != PMS7003_MAGIC)
+			return 2;
+
+		num = get_unaligned_be16(buf + 2);
+		if (num <= PMS7003_MAX_DATA_LENGTH) {
+			frame->expected_length = num;
+			frame->length = 0;
+		}
+
+		return 4;
+	}
+
+	num = min(size, (size_t)(frame->expected_length - frame->length));
+	memcpy(frame->data + frame->length, buf, num);
+	frame->length += num;
+
+	if (frame->length == frame->expected_length) {
+		if (pms7003_frame_is_okay(frame))
+			complete(&state->frame_ready);
+
+		frame->expected_length = 0;
+	}
+
+	return num;
+}
+
+static const struct serdev_device_ops pms7003_serdev_ops = {
+	.receive_buf = pms7003_receive_buf,
+	.write_wakeup = serdev_device_write_wakeup,
+};
+
+static void pms7003_stop(void *data)
+{
+	struct pms7003_state *state = data;
+
+	pms7003_do_cmd(state, CMD_SLEEP);
+}
+
+static const unsigned long pms7003_scan_masks[] = { 0x07, 0x00 };
+
+static int pms7003_probe(struct serdev_device *serdev)
+{
+	struct pms7003_state *state;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&serdev->dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	state = iio_priv(indio_dev);
+	serdev_device_set_drvdata(serdev, indio_dev);
+	state->serdev = serdev;
+	indio_dev->dev.parent = &serdev->dev;
+	indio_dev->info = &pms7003_info;
+	indio_dev->name = PMS7003_DRIVER_NAME;
+	indio_dev->channels = pms7003_channels,
+	indio_dev->num_channels = ARRAY_SIZE(pms7003_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->available_scan_masks = pms7003_scan_masks;
+
+	mutex_init(&state->lock);
+	init_completion(&state->frame_ready);
+
+	serdev_device_set_client_ops(serdev, &pms7003_serdev_ops);
+	ret = devm_serdev_device_open(&serdev->dev, serdev);
+	if (ret)
+		return ret;
+
+	serdev_device_set_baudrate(serdev, 9600);
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
+	if (ret)
+		return ret;
+
+	ret = pms7003_do_cmd(state, CMD_WAKEUP);
+	if (ret) {
+		dev_err(&serdev->dev, "failed to wakeup sensor\n");
+		return ret;
+	}
+
+	ret = pms7003_do_cmd(state, CMD_ENTER_PASSIVE_MODE);
+	if (ret) {
+		dev_err(&serdev->dev, "failed to enter passive mode\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&serdev->dev, pms7003_stop, state);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(&serdev->dev, indio_dev, NULL,
+					      pms7003_trigger_handler, NULL);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(&serdev->dev, indio_dev);
+}
+
+static const struct of_device_id pms7003_of_match[] = {
+	{ .compatible = "plantower,pms7003" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pms7003_of_match);
+
+static struct serdev_device_driver pms7003_driver = {
+	.driver = {
+		.name = PMS7003_DRIVER_NAME,
+		.of_match_table = pms7003_of_match,
+	},
+	.probe = pms7003_probe,
+};
+module_serdev_device_driver(pms7003_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Plantower PMS7003 particulate matter sensor driver");
+MODULE_LICENSE("GPL v2");
-- 
2.20.1

[PATCH v4 2/3] dt-bindings: add Plantower to the vendor prefixes

[Tomasz Duszynski]

Add Plantower to the vendor prefixes.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/vendor-prefixes.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 3cfe0c8b8250..fa391a650f3a 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -300,6 +300,7 @@ phytec	PHYTEC Messtechnik GmbH
 picochip	Picochip Ltd
 pine64	Pine64
 pixcir  PIXCIR MICROELECTRONICS Co., Ltd
+plantower Plantower Co., Ltd
 plathome	Plat'Home Co., Ltd.
 plda	PLDA
 plx	Broadcom Corporation (formerly PLX Technology)
-- 
2.20.1

[PATCH v4 3/3] dt-bindings: iio: chemical: pms7003: add device tree support

[Tomasz Duszynski]

Add device tree support for Plantower PMS7003 particulate matter sensor.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
---
 .../iio/chemical/plantower,pms7003.txt        | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt

diff --git a/Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt b/Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt
new file mode 100644
index 000000000000..7b5f06f324c8
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt
@@ -0,0 +1,20 @@
+* Plantower PMS7003 particulate matter sensor
+
+Required properties:
+- compatible: must be "plantower,pms7003"
+- vcc-supply: phandle to the regulator that provides power to the sensor
+
+Optional properties:
+- plantower,set-gpios: phandle to the GPIO connected to the SET line
+- reset-gpios: phandle to the GPIO connected to the RESET line
+
+Refer to serial/slave-device.txt for generic serial attached device bindings.
+
+Example:
+
+&uart0 {
+	air-pollution-sensor {
+		compatible = "plantower,pms7003";
+		vcc-supply = <&reg_vcc5v0>;
+	};
+};
-- 
2.20.1

Re: [PATCH v4 1/3] iio: chemical: add support for Plantower PMS7003 sensor

[Jonathan Cameron]

On Sat,  9 Feb 2019 18:36:07 +0100
Tomasz Duszynski <tduszyns@gmail.com> wrote:

> Add support for Plantower PMS7003 particulate matter sensor.
> 
> Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

I made a really small tweak to suppress a truncation
warning I just got testing building.  Not sure why GCC has started
getting fussy about deliberate casts.

thanks,

Jonathan

> ---
>  drivers/iio/chemical/Kconfig   |  10 +
>  drivers/iio/chemical/Makefile  |   1 +
>  drivers/iio/chemical/pms7003.c | 340 +++++++++++++++++++++++++++++++++
>  3 files changed, 351 insertions(+)
>  create mode 100644 drivers/iio/chemical/pms7003.c
> 
> diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
> index 57832b4360e9..d5d146e9e372 100644
> --- a/drivers/iio/chemical/Kconfig
> +++ b/drivers/iio/chemical/Kconfig
> @@ -61,6 +61,16 @@ config IAQCORE
>  	  iAQ-Core Continuous/Pulsed VOC (Volatile Organic Compounds)
>  	  sensors
>  
> +config PMS7003
> +	tristate "Plantower PMS7003 particulate matter sensor"
> +	depends on SERIAL_DEV_BUS
> +	help
> +	  Say Y here to build support for the Plantower PMS7003 particulate
> +	  matter sensor.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called pms7003.
> +
>  config SPS30
>  	tristate "SPS30 particulate matter sensor"
>  	depends on I2C
> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> index 65bf0f89c0e4..f5d1365acb49 100644
> --- a/drivers/iio/chemical/Makefile
> +++ b/drivers/iio/chemical/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_BME680_I2C) += bme680_i2c.o
>  obj-$(CONFIG_BME680_SPI) += bme680_spi.o
>  obj-$(CONFIG_CCS811)		+= ccs811.o
>  obj-$(CONFIG_IAQCORE)		+= ams-iaq-core.o
> +obj-$(CONFIG_PMS7003) += pms7003.o
>  obj-$(CONFIG_SENSIRION_SGP30)	+= sgp30.o
>  obj-$(CONFIG_SPS30) += sps30.o
>  obj-$(CONFIG_VZ89X)		+= vz89x.o
> diff --git a/drivers/iio/chemical/pms7003.c b/drivers/iio/chemical/pms7003.c
> new file mode 100644
> index 000000000000..0c913c60adde
> --- /dev/null
> +++ b/drivers/iio/chemical/pms7003.c
> @@ -0,0 +1,340 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Plantower PMS7003 particulate matter sensor driver
> + *
> + * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
> + */
> +
> +#include <asm/unaligned.h>
> +#include <linux/completion.h>
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/jiffies.h>
> +#include <linux/kernel.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/serdev.h>
> +
> +#define PMS7003_DRIVER_NAME "pms7003"
> +
> +#define PMS7003_MAGIC 0x424d
> +/* last 2 data bytes hold frame checksum */
> +#define PMS7003_MAX_DATA_LENGTH 28
> +#define PMS7003_CHECKSUM_LENGTH 2
> +#define PMS7003_PM10_OFFSET 10
> +#define PMS7003_PM2P5_OFFSET 8
> +#define PMS7003_PM1_OFFSET 6
> +
> +#define PMS7003_TIMEOUT msecs_to_jiffies(6000)
> +#define PMS7003_CMD_LENGTH 7
> +#define PMS7003_PM_MAX 1000
> +#define PMS7003_PM_MIN 0
> +
> +enum {
> +	PM1,
> +	PM2P5,
> +	PM10,
> +};
> +
> +enum pms7003_cmd {
> +	CMD_WAKEUP,
> +	CMD_ENTER_PASSIVE_MODE,
> +	CMD_READ_PASSIVE,
> +	CMD_SLEEP,
> +};
> +
> +/*
> + * commands have following format:
> + *
> + * +------+------+-----+------+-----+-----------+-----------+
> + * | 0x42 | 0x4d | cmd | 0x00 | arg | cksum msb | cksum lsb |
> + * +------+------+-----+------+-----+-----------+-----------+
> + */
> +static const u8 pms7003_cmd_tbl[][PMS7003_CMD_LENGTH] = {
> +	[CMD_WAKEUP] = { 0x42, 0x4d, 0xe4, 0x00, 0x01, 0x01, 0x74 },
> +	[CMD_ENTER_PASSIVE_MODE] = { 0x42, 0x4d, 0xe1, 0x00, 0x00, 0x01, 0x70 },
> +	[CMD_READ_PASSIVE] = { 0x42, 0x4d, 0xe2, 0x00, 0x00, 0x01, 0x71 },
> +	[CMD_SLEEP] = { 0x42, 0x4d, 0xe4, 0x00, 0x00, 0x01, 0x73 },
> +};
> +
> +struct pms7003_frame {
> +	u8 data[PMS7003_MAX_DATA_LENGTH];
> +	u16 expected_length;
> +	u16 length;
> +};
> +
> +struct pms7003_state {
> +	struct serdev_device *serdev;
> +	struct pms7003_frame frame;
> +	struct completion frame_ready;
> +	struct mutex lock; /* must be held whenever state gets touched */
> +};
> +
> +static int pms7003_do_cmd(struct pms7003_state *state, enum pms7003_cmd cmd)
> +{
> +	int ret;
> +
> +	ret = serdev_device_write(state->serdev, pms7003_cmd_tbl[cmd],
> +				  PMS7003_CMD_LENGTH, PMS7003_TIMEOUT);
> +	if (ret < PMS7003_CMD_LENGTH)
> +		return ret < 0 ? ret : -EIO;
> +
> +	ret = wait_for_completion_interruptible_timeout(&state->frame_ready,
> +							PMS7003_TIMEOUT);
> +	if (!ret)
> +		ret = -ETIMEDOUT;
> +
> +	return ret < 0 ? ret : 0;
> +}
> +
> +static u16 pms7003_get_pm(const u8 *data)
> +{
> +	return clamp_val(get_unaligned_be16(data),
> +			 PMS7003_PM_MIN, PMS7003_PM_MAX);
> +}
> +
> +static irqreturn_t pms7003_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct pms7003_state *state = iio_priv(indio_dev);
> +	struct pms7003_frame *frame = &state->frame;
> +	u16 data[3 + 1 + 4]; /* PM1, PM2P5, PM10, padding, timestamp */
> +	int ret;
> +
> +	mutex_lock(&state->lock);
> +	ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
> +	if (ret) {
> +		mutex_unlock(&state->lock);
> +		goto err;
> +	}
> +
> +	data[PM1] = pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET);
> +	data[PM2P5] = pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET);
> +	data[PM10] = pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET);
> +	mutex_unlock(&state->lock);
> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, data,
> +					   iio_get_time_ns(indio_dev));
> +err:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int pms7003_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int *val, int *val2, long mask)
> +{
> +	struct pms7003_state *state = iio_priv(indio_dev);
> +	struct pms7003_frame *frame = &state->frame;
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_PROCESSED:
> +		switch (chan->type) {
> +		case IIO_MASSCONCENTRATION:
> +			mutex_lock(&state->lock);
> +			ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
> +			if (ret) {
> +				mutex_unlock(&state->lock);
> +				return ret;
> +			}
> +
> +			*val = pms7003_get_pm(frame->data + chan->address);
> +			mutex_unlock(&state->lock);
> +
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info pms7003_info = {
> +	.read_raw = pms7003_read_raw,
> +};
> +
> +#define PMS7003_CHAN(_index, _mod, _addr) { \
> +	.type = IIO_MASSCONCENTRATION, \
> +	.modified = 1, \
> +	.channel2 = IIO_MOD_ ## _mod, \
> +	.address = _addr, \
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
> +	.scan_index = _index, \
> +	.scan_type = { \
> +		.sign = 'u', \
> +		.realbits = 10, \
> +		.storagebits = 16, \
> +		.endianness = IIO_CPU, \
> +	}, \
> +}
> +
> +static const struct iio_chan_spec pms7003_channels[] = {
> +	PMS7003_CHAN(0, PM1, PMS7003_PM1_OFFSET),
> +	PMS7003_CHAN(1, PM2P5, PMS7003_PM2P5_OFFSET),
> +	PMS7003_CHAN(2, PM10, PMS7003_PM10_OFFSET),
> +	IIO_CHAN_SOFT_TIMESTAMP(3),
> +};
> +
> +static u16 pms7003_calc_checksum(struct pms7003_frame *frame)
> +{
> +	u16 checksum = (PMS7003_MAGIC >> 8) + (u8)PMS7003_MAGIC +

So I'm getting a warning about truncating MAGIC by the cast.
I added a mask by 0xff as silly as it seems to suppress this.

Jonathan

> +		       (frame->length >> 8) + (u8)frame->length;
> +	int i;
> +
> +	for (i = 0; i < frame->length - PMS7003_CHECKSUM_LENGTH; i++)
> +		checksum += frame->data[i];
> +
> +	return checksum;
> +}
> +
> +static bool pms7003_frame_is_okay(struct pms7003_frame *frame)
> +{
> +	int offset = frame->length - PMS7003_CHECKSUM_LENGTH;
> +	u16 checksum = get_unaligned_be16(frame->data + offset);
> +
> +	return checksum == pms7003_calc_checksum(frame);
> +}
> +
> +static int pms7003_receive_buf(struct serdev_device *serdev,
> +			       const unsigned char *buf, size_t size)
> +{
> +	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
> +	struct pms7003_state *state = iio_priv(indio_dev);
> +	struct pms7003_frame *frame = &state->frame;
> +	int num;
> +
> +	if (!frame->expected_length) {
> +		u16 magic;
> +
> +		/* wait for SOF and data length */
> +		if (size < 4)
> +			return 0;
> +
> +		magic = get_unaligned_be16(buf);
> +		if (magic != PMS7003_MAGIC)
> +			return 2;
> +
> +		num = get_unaligned_be16(buf + 2);
> +		if (num <= PMS7003_MAX_DATA_LENGTH) {
> +			frame->expected_length = num;
> +			frame->length = 0;
> +		}
> +
> +		return 4;
> +	}
> +
> +	num = min(size, (size_t)(frame->expected_length - frame->length));
> +	memcpy(frame->data + frame->length, buf, num);
> +	frame->length += num;
> +
> +	if (frame->length == frame->expected_length) {
> +		if (pms7003_frame_is_okay(frame))
> +			complete(&state->frame_ready);
> +
> +		frame->expected_length = 0;
> +	}
> +
> +	return num;
> +}
> +
> +static const struct serdev_device_ops pms7003_serdev_ops = {
> +	.receive_buf = pms7003_receive_buf,
> +	.write_wakeup = serdev_device_write_wakeup,
> +};
> +
> +static void pms7003_stop(void *data)
> +{
> +	struct pms7003_state *state = data;
> +
> +	pms7003_do_cmd(state, CMD_SLEEP);
> +}
> +
> +static const unsigned long pms7003_scan_masks[] = { 0x07, 0x00 };
> +
> +static int pms7003_probe(struct serdev_device *serdev)
> +{
> +	struct pms7003_state *state;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&serdev->dev, sizeof(*state));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	state = iio_priv(indio_dev);
> +	serdev_device_set_drvdata(serdev, indio_dev);
> +	state->serdev = serdev;
> +	indio_dev->dev.parent = &serdev->dev;
> +	indio_dev->info = &pms7003_info;
> +	indio_dev->name = PMS7003_DRIVER_NAME;
> +	indio_dev->channels = pms7003_channels,
> +	indio_dev->num_channels = ARRAY_SIZE(pms7003_channels);
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->available_scan_masks = pms7003_scan_masks;
> +
> +	mutex_init(&state->lock);
> +	init_completion(&state->frame_ready);
> +
> +	serdev_device_set_client_ops(serdev, &pms7003_serdev_ops);
> +	ret = devm_serdev_device_open(&serdev->dev, serdev);
> +	if (ret)
> +		return ret;
> +
> +	serdev_device_set_baudrate(serdev, 9600);
> +	serdev_device_set_flow_control(serdev, false);
> +
> +	ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
> +	if (ret)
> +		return ret;
> +
> +	ret = pms7003_do_cmd(state, CMD_WAKEUP);
> +	if (ret) {
> +		dev_err(&serdev->dev, "failed to wakeup sensor\n");
> +		return ret;
> +	}
> +
> +	ret = pms7003_do_cmd(state, CMD_ENTER_PASSIVE_MODE);
> +	if (ret) {
> +		dev_err(&serdev->dev, "failed to enter passive mode\n");
> +		return ret;
> +	}
> +
> +	ret = devm_add_action_or_reset(&serdev->dev, pms7003_stop, state);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_iio_triggered_buffer_setup(&serdev->dev, indio_dev, NULL,
> +					      pms7003_trigger_handler, NULL);
> +	if (ret)
> +		return ret;
> +
> +	return devm_iio_device_register(&serdev->dev, indio_dev);
> +}
> +
> +static const struct of_device_id pms7003_of_match[] = {
> +	{ .compatible = "plantower,pms7003" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, pms7003_of_match);
> +
> +static struct serdev_device_driver pms7003_driver = {
> +	.driver = {
> +		.name = PMS7003_DRIVER_NAME,
> +		.of_match_table = pms7003_of_match,
> +	},
> +	.probe = pms7003_probe,
> +};
> +module_serdev_device_driver(pms7003_driver);
> +
> +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
> +MODULE_DESCRIPTION("Plantower PMS7003 particulate matter sensor driver");
> +MODULE_LICENSE("GPL v2");

Re: [PATCH v4 2/3] dt-bindings: add Plantower to the vendor prefixes

[Jonathan Cameron]

On Sat,  9 Feb 2019 18:36:08 +0100
Tomasz Duszynski <tduszyns@gmail.com> wrote:

> Add Plantower to the vendor prefixes.
> 
> Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to ignore this.

Thanks,

Jonathan

> ---
>  Documentation/devicetree/bindings/vendor-prefixes.txt | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
> index 3cfe0c8b8250..fa391a650f3a 100644
> --- a/Documentation/devicetree/bindings/vendor-prefixes.txt
> +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
> @@ -300,6 +300,7 @@ phytec	PHYTEC Messtechnik GmbH
>  picochip	Picochip Ltd
>  pine64	Pine64
>  pixcir  PIXCIR MICROELECTRONICS Co., Ltd
> +plantower Plantower Co., Ltd
>  plathome	Plat'Home Co., Ltd.
>  plda	PLDA
>  plx	Broadcom Corporation (formerly PLX Technology)

Re: [PATCH v4 3/3] dt-bindings: iio: chemical: pms7003: add device tree support

[Jonathan Cameron]

On Sat,  9 Feb 2019 18:36:09 +0100
Tomasz Duszynski <tduszyns@gmail.com> wrote:

> Add device tree support for Plantower PMS7003 particulate matter sensor.
> 
> Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Applied to the togreg branch of iio.git and pushed out as testing.

I'll be doing a pull request pretty soon on this given where we are
in the cycle.  If anyone has last minute reviews, there is still a little
time.

Thanks,

Jonathan

> ---
>  .../iio/chemical/plantower,pms7003.txt        | 20 +++++++++++++++++++
>  1 file changed, 20 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt b/Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt
> new file mode 100644
> index 000000000000..7b5f06f324c8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt
> @@ -0,0 +1,20 @@
> +* Plantower PMS7003 particulate matter sensor
> +
> +Required properties:
> +- compatible: must be "plantower,pms7003"
> +- vcc-supply: phandle to the regulator that provides power to the sensor
> +
> +Optional properties:
> +- plantower,set-gpios: phandle to the GPIO connected to the SET line
> +- reset-gpios: phandle to the GPIO connected to the RESET line
> +
> +Refer to serial/slave-device.txt for generic serial attached device bindings.
> +
> +Example:
> +
> +&uart0 {
> +	air-pollution-sensor {
> +		compatible = "plantower,pms7003";
> +		vcc-supply = <&reg_vcc5v0>;
> +	};
> +};