iio: srf08: add support for srf02 in i2c mode

srf02 added with support for i2c interface

Attributes for setting max range or sensitivity are omitted for the case of srf02 type sensor, because they are not supported by the hardware.

Signed-off-by Andreas Klinger <ak-n176/[email protected]>

---
 drivers/iio/proximity/Kconfig |  8 ++---
 drivers/iio/proximity/srf08.c | 77 ++++++++++++++++++++++++++++++++-----------
 2 files changed, 62 insertions(+), 23 deletions(-)

drivers/iio/proximity/Kconfig +4 -4

index df33ccc0d035..ae070950f920 100644
@@ -57,12 +57,12 @@ config SX9500
 	  module will be called sx9500.
 
 config SRF08
-	tristate "Devantech SRF08/SRF10 ultrasonic ranger sensor"
+	tristate "Devantech SRF02/SRF08/SRF10 ultrasonic ranger sensor"
 	depends on I2C
 	help
-	  Say Y here to build a driver for Devantech SRF08/SRF10 ultrasonic
-	  ranger sensor. This driver can be used to measure the distance
-	  of objects.
+	  Say Y here to build a driver for Devantech SRF02/SRF08/SRF10
+	  ultrasonic ranger sensors with i2c interface.
+	  This driver can be used to measure the distance of objects.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called srf08.

drivers/iio/proximity/srf08.c +8 -5

index 52573b013313..6ccf8f9fd703 100644
@@ -1,15 +1,17 @@
 /*
- * srf08.c - Support for Devantech SRF08 ultrasonic ranger
+ * srf08.c - Support for Devantech SRF02/SRF08/SRF10 ultrasonic ranger
+ *           with I2C-Interface
  *
- * Copyright (c) 2016 Andreas Klinger <ak-n176/[email protected]>
+ * Copyright (c) 2016, 2017 Andreas Klinger <ak-n176/[email protected]>
  *
  * This file is subject to the terms and conditions of version 2 of
- * the GNU General Public License.  See the file COPYING in the main
+ * the GNU General Public License. See the file COPYING in the main
  * directory of this archive for more details.
  *
  * For details about the device see:
  * http://www.robot-electronics.co.uk/htm/srf08tech.html
  * http://www.robot-electronics.co.uk/htm/srf10tech.htm
+ * http://www.robot-electronics.co.uk/htm/srf02tech.htm
  */
 
 #include <linux/err.h>

@@ -34,11 +36,10 @@
 
 #define SRF08_CMD_RANGING_CM	0x51	/* Ranging Mode - Result in cm */
 
-#define SRF08_DEFAULT_RANGE	6020	/* default value of Range in mm */
-
 #define SRF08_MAX_SENSITIVITY	32	/* number of Gain Register values */
 
 enum srf08_sensor_type {
+	SRF02,
 	SRF08,
 	SRF10,
 	SRF_MAX_TYPE

@@ -75,6 +76,8 @@ struct srf08_data {
  * is called "Sensitivity" here.
  */
 static const int srf08_sensitivity[SRF_MAX_TYPE][SRF08_MAX_SENSITIVITY] = {
+	[SRF02] = {
+	},
 	[SRF08] = {
 	 94,  97, 100, 103, 107, 110, 114, 118,
 	123, 128, 133, 139, 145, 152, 159, 168,

drivers/iio/proximity/srf08.c +20 -1

+	[SRF08] = 6020,
+	[SRF10] = 6020,
+};
+
 static int srf08_read_ranging(struct srf08_data *data)
 {
 	struct i2c_client *client = data->client;

@@ -409,6 +417,15 @@ static const struct iio_info srf08_info = {
 	.driver_module = THIS_MODULE,
 };
 
+/*
+ * srf02 don't have an adjustable range or sensitivity,
+ * so we don't need attributes at all
+ */
+static const struct iio_info srf02_info = {
+	.read_raw = srf08_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
 static int srf08_probe(struct i2c_client *client,
 					 const struct i2c_device_id *id)
 {

@@ -434,7 +451,13 @@ static int srf08_probe(struct i2c_client *client,
 	indio_dev->name = id->name;
 	indio_dev->dev.parent = &client->dev;
 	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->info = &srf08_info;
+
+	/* srf02 is not using sensitivity nor max_range */
+	if (id->driver_data == SRF02)
+		indio_dev->info = &srf02_info;
+	else
+		indio_dev->info = &srf08_info;
+
 	indio_dev->channels = srf08_channels;
 	indio_dev->num_channels = ARRAY_SIZE(srf08_channels);
 

@@ -447,24 +470,39 @@ static int srf08_probe(struct i2c_client *client,
 		return ret;
 	}

drivers/iio/proximity/srf08.c +28 -5

+		/*
+		 * set default range of device here
+		 * these register values cannot be read from he hardware
+		 * therefore set driver specific default values
+		 *
+		 * srf02 don't have a default value so it'll be omitted
+		 */
+		ret = srf08_write_range_mm(data,
+					srf08_default_range[id->driver_data]);
+		if (ret < 0)
+			return ret;
+	}
 
-	ret = srf08_write_sensitivity(data,
-			srf08_default_sensitivity[id->driver_data]);
-	if (ret < 0)
-		return ret;
+	if (srf08_default_sensitivity[id->driver_data]) {
+		/*
+		 * set default sensitivity of device here
+		 * these register values cannot be read from the hardware
+		 * therefore set driver specific default values
+		 *
+		 * srf02 don't have a default value so it'll be omitted
+		 */
+		ret = srf08_write_sensitivity(data,
+				srf08_default_sensitivity[id->driver_data]);
+		if (ret < 0)
+			return ret;
+	}
 
 	return devm_iio_device_register(&client->dev, indio_dev);
 }
 
 static const struct of_device_id of_srf08_match[] = {
+	{ .compatible = "devantech,srf02", (void *)SRF02},
 	{ .compatible = "devantech,srf08", (void *)SRF08},
 	{ .compatible = "devantech,srf10", (void *)SRF10},
 	{},

@@ -473,6 +511,7 @@ static const struct of_device_id of_srf08_match[] = {
 MODULE_DEVICE_TABLE(of, of_srf08_match);
 
 static const struct i2c_device_id srf08_id[] = {
+	{ "srf02", SRF02 },
 	{ "srf08", SRF08 },
 	{ "srf10", SRF10 },
 	{ }

@@ -490,5 +529,5 @@ static struct i2c_driver srf08_driver = {
 module_i2c_driver(srf08_driver);
 
 MODULE_AUTHOR("Andreas Klinger <ak-n176/[email protected]>");
-MODULE_DESCRIPTION("Devantech SRF08/SRF10 ultrasonic ranger driver");
+MODULE_DESCRIPTION("Devantech SRF02/SRF08/SRF10 i2c ultrasonic ranger driver");
 MODULE_LICENSE("GPL");