[PATCH v3 0/2] iio: proximity: driver for vcnl3020

[PATCH v3 0/2] iio: proximity: driver for vcnl3020

[Ivan Mikhaylov]

Add proximity sensor driver for Vishay vcnl3020. Only on-demand
measurement is supported for now.

Changes from v2:
   1. using regmap_read_poll_timeout instead of do-while in measurement
      function.
   2. change struct i2client* in vcnl3020_data to struct dev*
   3. enable REGMAP_I2C in Kconfig.

Changes from v1:
   1. using regmap interface instead of i2c_smbus_* calls.
   2. switch from probe to probe_new.
   3. s32/int32_t -> int

Ivan Mikhaylov (2):
  iio: proximity: provide device tree binding document
  iio: proximity: Add driver support for vcnl3020 proximity sensor

 .../bindings/iio/proximity/vcnl3020.yaml      |  47 ++++
 drivers/iio/proximity/Kconfig                 |  11 +
 drivers/iio/proximity/Makefile                |   1 +
 drivers/iio/proximity/vcnl3020.c              | 233 ++++++++++++++++++
 4 files changed, 292 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/proximity/vcnl3020.yaml
 create mode 100644 drivers/iio/proximity/vcnl3020.c

-- 
2.21.1

[PATCH v3 1/2] iio: proximity: provide device tree binding document

[Ivan Mikhaylov]

Mostly standard i2c driver with some additional led-current option
for vcnl3020.

Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
---
 .../bindings/iio/proximity/vcnl3020.yaml      | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/proximity/vcnl3020.yaml

diff --git a/Documentation/devicetree/bindings/iio/proximity/vcnl3020.yaml b/Documentation/devicetree/bindings/iio/proximity/vcnl3020.yaml
new file mode 100644
index 000000000000..76c29514c663
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/proximity/vcnl3020.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/proximity/vcnl3020.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Integrated Proximity Sensor With Infrared Emitter
+
+maintainers:
+  - Ivan Mikhaylov <i.mikhaylov@yadro.com>
+
+description: |
+  The VCNL3020 is a fully integrated proximity sensor. Fully integrated means
+  that the infrared emitter is included in the package. It has 16-bit
+  resolution. It includes a signal processing IC and features standard I2C
+  communication interface. It features an interrupt function.
+
+  Specifications about the devices can be found at:
+  https://www.vishay.com/docs/84150/vcnl3020.pdf
+
+properties:
+  compatible:
+    enum:
+      - vishay,vcnl3020
+
+  reg:
+    maxItems: 1
+
+  led-current:
+    description:
+        IR LED current value with valid Range = 0 to 20d. e.g. 0 = 0 mA,
+        1 = 10 mA, 20 = 200 mA (2 = 20 mA = DEFAULT). LED Current is
+        limited to 200 mA for values higher than decimal 20.
+
+required:
+  - compatible
+  - reg
+  - led-current
+
+examples:
+  - |
+    iio-proximity@13 {
+       compatible = "vishay,vcnl3020";
+       reg = <0x13>;
+
+       led-current = <0x14>;
+    };
-- 
2.21.1

[PATCH v3 2/2] iio: proximity: Add driver support for vcnl3020 proximity sensor

[Ivan Mikhaylov]

Proximity sensor driver based on light/vcnl4000.c code.
For now supports only the single on-demand measurement.

The VCNL3020 is a fully integrated proximity sensor. Fully
integrated means that the infrared emitter is included in the
package. It has 16-bit resolution. It includes a signal
processing IC and features standard I2C communication
interface. It features an interrupt function.

Datasheet: http://www.vishay.com/docs/84150/vcnl3020.pdf
Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
---
 drivers/iio/proximity/Kconfig    |  11 ++
 drivers/iio/proximity/Makefile   |   1 +
 drivers/iio/proximity/vcnl3020.c | 233 +++++++++++++++++++++++++++++++
 3 files changed, 245 insertions(+)
 create mode 100644 drivers/iio/proximity/vcnl3020.c

diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
index d53601447da4..b8d2b17e60ac 100644
--- a/drivers/iio/proximity/Kconfig
+++ b/drivers/iio/proximity/Kconfig
@@ -112,6 +112,17 @@ config SRF08
 	  To compile this driver as a module, choose M here: the
 	  module will be called srf08.
 
+config VCNL3020
+	tristate "VCNL3020 proximity sensor"
+	select REGMAP_I2C
+	depends on I2C
+	help
+	  Say Y here if you want to build a driver for the Vishay VCNL3020
+	  proximity sensor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called vcnl3020.
+
 config VL53L0X_I2C
 	tristate "STMicroelectronics VL53L0X ToF ranger sensor (I2C)"
 	depends on I2C
diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
index 0bb5f9de13d6..8245978ced30 100644
--- a/drivers/iio/proximity/Makefile
+++ b/drivers/iio/proximity/Makefile
@@ -12,5 +12,6 @@ obj-$(CONFIG_RFD77402)		+= rfd77402.o
 obj-$(CONFIG_SRF04)		+= srf04.o
 obj-$(CONFIG_SRF08)		+= srf08.o
 obj-$(CONFIG_SX9500)		+= sx9500.o
+obj-$(CONFIG_VCNL3020)		+= vcnl3020.o
 obj-$(CONFIG_VL53L0X_I2C)	+= vl53l0x-i2c.o
 
diff --git a/drivers/iio/proximity/vcnl3020.c b/drivers/iio/proximity/vcnl3020.c
new file mode 100644
index 000000000000..c94c16120600
--- /dev/null
+++ b/drivers/iio/proximity/vcnl3020.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Support for Vishay VCNL3020 proximity sensor on i2c bus.
+ * Based on Vishay VCNL4000 driver code.
+ *
+ * TODO: interrupts.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define VCNL_DRV_NAME		"vcnl3020"
+#define VCNL_REGMAP_NAME	"vcnl3020_regmap"
+#define VCNL3020_PROD_ID	0x21
+
+#define VCNL_COMMAND		0x80 /* Command register */
+#define VCNL_PROD_REV		0x81 /* Product ID and Revision ID */
+#define VCNL_PROXIMITY_RATE	0x82 /* Rate of Proximity Measurement */
+#define VCNL_LED_CURRENT	0x83 /* IR LED current for proximity mode */
+#define VCNL_PS_RESULT_HI	0x87 /* Proximity result register, MSB */
+#define VCNL_PS_RESULT_LO	0x88 /* Proximity result register, LSB */
+#define VCNL_PS_ICR		0x89 /* Interrupt Control Register  */
+
+#define VCNL_PS_LO_THR_HI	0x8a /* High byte of low threshold value */
+#define VCNL_PS_LO_THR_LO	0x8b /* Low byte of low threshold value */
+#define VCNL_PS_HI_THR_HI	0x8c /* High byte of high threshold value */
+#define VCNL_PS_HI_THR_LO	0x8d /* Low byte of high threshold value */
+#define VCNL_ISR		0x8e /* Interrupt Status Register */
+#define VCNL_PS_MOD_ADJ		0x8f /* Proximity Modulator Timing Adjustment */
+
+/* Bit masks for COMMAND register */
+#define VCNL_PS_RDY		BIT(5) /* proximity data ready? */
+#define VCNL_PS_OD		BIT(3) /* start on-demand proximity
+					* measurement
+					*/
+
+#define VCNL_ON_DEMAND_TIMEOUT	100000 /* on-demand measurement timeout in us */
+#define VCNL_POLL_US		20000
+
+struct vcnl3020_data {
+	struct regmap *regmap;
+	struct device *dev;
+	u8 rev;
+	struct mutex lock;
+};
+
+static int vcnl3020_init(struct vcnl3020_data *data)
+{
+	int rc;
+	unsigned int reg;
+	u32 led_current;
+
+	rc = device_property_read_u32(data->dev, "led-current", &led_current);
+	if (rc) {
+		dev_err(data->dev, "Couldn't get led current (%d)", rc);
+		return rc;
+	}
+
+	rc = regmap_read(data->regmap, VCNL_PROD_REV, &reg);
+	if (rc) {
+		dev_err(data->dev,
+			"Error (%d) reading product revision", rc);
+		return rc;
+	}
+
+	if (reg == VCNL3020_PROD_ID) {
+		data->rev = reg;
+		mutex_init(&data->lock);
+	} else {
+		dev_err(data->dev,
+			"Product id (%x) did not match vcnl3020 (%x)", reg,
+			VCNL3020_PROD_ID);
+		return -ENODEV;
+	}
+
+	/* set led current */
+	rc = regmap_write(data->regmap, VCNL_LED_CURRENT, led_current);
+	if (rc) {
+		dev_err(data->dev, "Error (%d) setting LED current", rc);
+	}
+
+	return rc;
+};
+
+static int vcnl3020_measure_proximity(struct vcnl3020_data *data, int *val)
+{
+	int rc;
+	unsigned int reg;
+
+	mutex_lock(&data->lock);
+
+	rc = regmap_write(data->regmap, VCNL_COMMAND, VCNL_PS_OD);
+	if (rc)
+		goto err_unlock;
+
+	/* wait for data to become ready */
+	rc = regmap_read_poll_timeout(data->regmap, VCNL_COMMAND, reg,
+				      reg & VCNL_PS_RDY, VCNL_POLL_US,
+				      VCNL_ON_DEMAND_TIMEOUT);
+	if (rc) {
+		dev_err(data->dev,
+			"vcnl3020_measure() failed, data is not ready");
+		goto err_unlock;
+	}
+
+	rc = regmap_read(data->regmap, VCNL_PS_RESULT_HI, &reg);
+	if (rc)
+		goto err_unlock;
+	*val = reg << 8;
+	dev_dbg(data->dev, "result high byte 0x%x", rc);
+
+	rc = regmap_read(data->regmap, VCNL_PS_RESULT_LO, &reg);
+	if (rc)
+		goto err_unlock;
+	*val |= reg;
+	dev_dbg(data->dev, "result low byte 0x%x", rc);
+
+err_unlock:
+	mutex_unlock(&data->lock);
+
+	return rc;
+}
+
+static const struct iio_chan_spec vcnl3020_channels[] = {
+	{
+		.type = IIO_PROXIMITY,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+	},
+};
+
+static int vcnl3020_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int *val,
+			     int *val2, long mask)
+{
+	int rc;
+	struct vcnl3020_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_PROXIMITY:
+			rc = vcnl3020_measure_proximity(data, val);
+			if (rc)
+				return rc;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info vcnl3020_info = {
+	.read_raw = vcnl3020_read_raw,
+};
+
+static const struct regmap_config vcnl3020_regmap_config = {
+	.name		= VCNL_REGMAP_NAME,
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.max_register	= VCNL_PS_MOD_ADJ,
+};
+
+static int vcnl3020_probe(struct i2c_client *client)
+{
+	struct vcnl3020_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	int rc;
+
+	regmap = devm_regmap_init_i2c(client, &vcnl3020_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "regmap_init failed!\n");
+		return PTR_ERR(regmap);
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->regmap = regmap;
+	data->dev = &client->dev;
+
+	rc = vcnl3020_init(data);
+	if (rc)
+		return rc;
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &vcnl3020_info;
+	indio_dev->channels = vcnl3020_channels;
+	indio_dev->num_channels = ARRAY_SIZE(vcnl3020_channels);
+	indio_dev->name = VCNL_DRV_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id vcnl3020_id[] = {
+	{ "vcnl3020", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, vcnl3020_id);
+
+static const struct of_device_id vcnl3020_of_match[] = {
+	{
+		.compatible = "vishay,vcnl3020",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, vcnl3020_of_match);
+
+static struct i2c_driver vcnl3020_driver = {
+	.driver = {
+		.name   = VCNL_DRV_NAME,
+		.of_match_table = vcnl3020_of_match,
+	},
+	.probe_new  = vcnl3020_probe,
+	.id_table = vcnl3020_id,
+};
+module_i2c_driver(vcnl3020_driver);
+
+MODULE_AUTHOR("Ivan Mikhaylov <i.mikhaylov@yadro.com>");
+MODULE_DESCRIPTION("Vishay VCNL3020 proximity sensor driver");
+MODULE_LICENSE("GPL");
-- 
2.21.1

Re: [PATCH v3 2/2] iio: proximity: Add driver support for vcnl3020 proximity sensor

[Andy Shevchenko]

On Thu, Mar 26, 2020 at 5:51 PM Ivan Mikhaylov <i.mikhaylov@yadro.com> wrote:
>
> Proximity sensor driver based on light/vcnl4000.c code.
> For now supports only the single on-demand measurement.
>
> The VCNL3020 is a fully integrated proximity sensor. Fully
> integrated means that the infrared emitter is included in the
> package. It has 16-bit resolution. It includes a signal
> processing IC and features standard I2C communication
> interface. It features an interrupt function.

Thank you for an update, my (only minors) comments below.
After addressing them,

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

(Don't forget to fix DTS schema as Rob's bot pointed out)

...

> +#define VCNL_ON_DEMAND_TIMEOUT 100000 /* on-demand measurement timeout in us */

This also should have _US suffix, and thus comment is not necessary.

> +#define VCNL_POLL_US           20000

...

> +       if (reg == VCNL3020_PROD_ID) {
> +               data->rev = reg;
> +               mutex_init(&data->lock);
> +       } else {
> +               dev_err(data->dev,
> +                       "Product id (%x) did not match vcnl3020 (%x)", reg,
> +                       VCNL3020_PROD_ID);
> +               return -ENODEV;
> +       }

I would recommend to use standard pattern, i.e.
  if (reg != ...) {
    ...error handling...
  }

in this case else branch becomes a mainstream code in the function.

...

> +       rc = regmap_write(data->regmap, VCNL_LED_CURRENT, led_current);
> +       if (rc) {
> +               dev_err(data->dev, "Error (%d) setting LED current", rc);
> +       }

Now curly braces are redundant.

> +       return rc;

...

> +       rc = regmap_read(data->regmap, VCNL_PS_RESULT_HI, &reg);
> +       if (rc)
> +               goto err_unlock;

> +       *val = reg << 8;

This actually breaks the principle of not touching output buffers /
variables in case of error.

Perhaps

    unsigned int hi, lo;

instead of / along with reg?

> +       dev_dbg(data->dev, "result high byte 0x%x", rc);
> +
> +       rc = regmap_read(data->regmap, VCNL_PS_RESULT_LO, &reg);
> +       if (rc)
> +               goto err_unlock;
> +       *val |= reg;
> +       dev_dbg(data->dev, "result low byte 0x%x", rc);

-- 
With Best Regards,
Andy Shevchenko