[PATCH 1/1] iio: cros_ec: add 'id' sysfs entry

[Fabien Lahoudere <fabien.lahoudere@collabora.com>]

From: Gwendal Grignou <gwendal@chromium.org>

This new sysfs entry is used to interpret ring buffer information,
mainly by Android sensor HAL.
It expand to all sensors, the documentation about 'id' we can found
in Documentation/ABI/testing/sysfs-bus-iio-cros-ec.

Also fix typo in docs, I replace 'Septembre' by 'September'.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.com>
---
 Documentation/ABI/testing/sysfs-bus-iio-cros-ec    | 10 +++++-----
 .../common/cros_ec_sensors/cros_ec_sensors_core.c  | 14 ++++++++++++++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-cros-ec b/Documentation/ABI/testing/sysfs-bus-iio-cros-ec
index 0e95c2ca105c..6158f831c761 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio-cros-ec
+++ b/Documentation/ABI/testing/sysfs-bus-iio-cros-ec
@@ -18,11 +18,11 @@ Description:
 		values are 'base' and 'lid'.
 
 What:		/sys/bus/iio/devices/iio:deviceX/id
-Date:		Septembre 2017
+Date:		September 2017
 KernelVersion:	4.14
 Contact:	linux-iio@vger.kernel.org
 Description:
-		This attribute is exposed by the CrOS EC legacy accelerometer
-		driver and represents the sensor ID as exposed by the EC. This
-		ID is used by the Android sensor service hardware abstraction
-		layer (sensor HAL) through the Android container on ChromeOS.
+		This attribute is exposed by the CrOS EC sensors driver and
+		represents the sensor ID as exposed by the EC. This ID is used
+		by the Android sensor service hardware abstraction layer (sensor
+		HAL) through the Android container on ChromeOS.
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 719a0df5aeeb..130362ca421b 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -125,6 +125,15 @@ static ssize_t cros_ec_sensors_calibrate(struct iio_dev *indio_dev,
 	return ret ? ret : len;
 }
 
+static ssize_t cros_ec_sensors_id(struct iio_dev *indio_dev,
+				  uintptr_t private,
+				  const struct iio_chan_spec *chan, char *buf)
+{
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", st->param.info.sensor_num);
+}
+
 static ssize_t cros_ec_sensors_loc(struct iio_dev *indio_dev,
 		uintptr_t private, const struct iio_chan_spec *chan,
 		char *buf)
@@ -140,6 +149,11 @@ const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = {
 		.shared = IIO_SHARED_BY_ALL,
 		.write = cros_ec_sensors_calibrate
 	},
+	{
+		.name = "id",
+		.shared = IIO_SHARED_BY_ALL,
+		.read = cros_ec_sensors_id
+	},
 	{
 		.name = "location",
 		.shared = IIO_SHARED_BY_ALL,
-- 
2.19.2