[PATCH v4 1/1] iio: ltr301: Add support for ltr301

[Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>]

Added support for Liteon 301 Ambient light sensor. Since
LTR-301 and LTR-501 are register compatible(and even have same
part id), LTR-501 driver has been extended to support both
devices. LTR-501 is similar to LTR-301 in ALS sensing, But the
only difference is, LTR-501 also supports proximity sensing.

LTR-501 - ALS + Proximity combo
LTR-301 - ALS sensor.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
 drivers/iio/light/Kconfig  |  2 +-
 drivers/iio/light/ltr501.c | 55 +++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index a224afd..215e4a3 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -159,7 +159,7 @@ config LTR501
 	select IIO_TRIGGERED_BUFFER
 	help
 	 If you say yes here you get support for the Lite-On LTR-501ALS-01
-	 ambient light and proximity sensor.
+	 ambient light and proximity sensor or LTR-301 ambient light sensor.
 
 	 This driver can also be built as a module.  If so, the module
          will be called ltr501.
diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
index 62b7072..5cb0427 100644
--- a/drivers/iio/light/ltr501.c
+++ b/drivers/iio/light/ltr501.c
@@ -45,10 +45,16 @@
 
 #define LTR501_PS_DATA_MASK 0x7ff
 
+enum ltr_chipset {
+	LTR301,
+	LTR501,
+};
+
 struct ltr501_data {
 	struct i2c_client *client;
 	struct mutex lock_als, lock_ps;
 	u8 als_contr, ps_contr;
+	u8 chip_id;
 };
 
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
@@ -124,6 +130,13 @@ static const struct iio_chan_spec ltr501_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
+static const struct iio_chan_spec ltr301_channels[] = {
+	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
+	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
+		BIT(IIO_CHAN_INFO_SCALE)),
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
 static const int ltr501_ps_gain[4][2] = {
 	{1, 0}, {0, 250000}, {0, 125000}, {0, 62500}
 };
@@ -244,10 +257,19 @@ static struct attribute *ltr501_attributes[] = {
 	NULL
 };
 
+static struct attribute *ltr301_attributes[] = {
+	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
+	NULL
+};
+
 static const struct attribute_group ltr501_attribute_group = {
 	.attrs = ltr501_attributes,
 };
 
+static const struct attribute_group ltr301_attribute_group = {
+	.attrs = ltr301_attributes,
+};
+
 static const struct iio_info ltr501_info = {
 	.read_raw = ltr501_read_raw,
 	.write_raw = ltr501_write_raw,
@@ -255,6 +277,13 @@ static const struct iio_info ltr501_info = {
 	.driver_module = THIS_MODULE,
 };
 
+static const struct iio_info ltr301_info = {
+	.read_raw = ltr501_read_raw,
+	.write_raw = ltr501_write_raw,
+	.attrs = &ltr301_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
 static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)
 {
 	int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);
@@ -347,6 +376,13 @@ static int ltr501_probe(struct i2c_client *client,
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
+
+	/* TODO: Add condition for ACPI */
+	if (id)
+		data->chip_id = id->driver_data;
+	else
+		return -ENODEV;
+
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);
 
@@ -357,12 +393,24 @@ static int ltr501_probe(struct i2c_client *client,
 		return -ENODEV;
 
 	indio_dev->dev.parent = &client->dev;
-	indio_dev->info = &ltr501_info;
-	indio_dev->channels = ltr501_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
 	indio_dev->name = LTR501_DRV_NAME;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
+	switch (data->chip_id) {
+	case LTR301:
+		indio_dev->info = &ltr301_info;
+		indio_dev->channels = ltr301_channels;
+		break;
+	case LTR501:
+		indio_dev->info = &ltr501_info;
+		indio_dev->channels = ltr501_channels;
+		break;
+	default:
+		dev_warn(&client->dev, "ltr chip invalid\n");
+		return -ENODEV;
+	}
+
 	ret = ltr501_init(data);
 	if (ret < 0)
 		return ret;
@@ -422,7 +470,8 @@ static int ltr501_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);
 
 static const struct i2c_device_id ltr501_id[] = {
-	{ "ltr501", 0 },
+	{ "ltr301", LTR301 },
+	{ "ltr501", LTR501 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ltr501_id);
-- 
1.9.1