iio: vcnl4000: make the driver extendable

There are similar chips in the vcnl4xxx family. The initialization and
communication is a bit different for members of the family, so this
patch makes the driver extendable for different chips.

There is no functional change.
Signed-off-by: Tomas Novotny <tomas@novotny.cz>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/vcnl4000.c

@@ -26,8 +26,8 @@
 #include <linux/iio/sysfs.h>
 
 #define VCNL4000_DRV_NAME "vcnl4000"
-#define VCNL4000_ID		0x01
-#define VCNL4010_ID		0x02 /* for VCNL4020, VCNL4010 */
+#define VCNL4000_PROD_ID	0x01
+#define VCNL4010_PROD_ID	0x02 /* for VCNL4020, VCNL4010 */
 
 #define VCNL4000_COMMAND	0x80 /* Command register */
 #define VCNL4000_PROD_REV	0x81 /* Product ID and Revision ID */
@@ -46,17 +46,50 @@
 #define VCNL4000_AL_OD		BIT(4) /* start on-demand ALS measurement */
 #define VCNL4000_PS_OD		BIT(3) /* start on-demand proximity measurement */
 
+enum vcnl4000_device_ids {
+	VCNL4000,
+};
+
 struct vcnl4000_data {
 	struct i2c_client *client;
+	enum vcnl4000_device_ids id;
+	int rev;
+	int al_scale;
+	const struct vcnl4000_chip_spec *chip_spec;
 	struct mutex lock;
 };
 
+struct vcnl4000_chip_spec {
+	const char *prod;
+	int (*init)(struct vcnl4000_data *data);
+	int (*measure_light)(struct vcnl4000_data *data, int *val);
+	int (*measure_proximity)(struct vcnl4000_data *data, int *val);
+};
+
 static const struct i2c_device_id vcnl4000_id[] = {
-	{ "vcnl4000", 0 },
+	{ "vcnl4000", VCNL4000 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, vcnl4000_id);
 
+static int vcnl4000_init(struct vcnl4000_data *data)
+{
+	int ret, prod_id;
+
+	ret = i2c_smbus_read_byte_data(data->client, VCNL4000_PROD_REV);
+	if (ret < 0)
+		return ret;
+
+	prod_id = ret >> 4;
+	if (prod_id != VCNL4010_PROD_ID && prod_id != VCNL4000_PROD_ID)
+		return -ENODEV;
+
+	data->rev = ret & 0xf;
+	data->al_scale = 250000;
+
+	return 0;
+};
+
 static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
 				u8 rdy_mask, u8 data_reg, int *val)
 {
@@ -103,6 +136,29 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
 	return ret;
 }
 
+static int vcnl4000_measure_light(struct vcnl4000_data *data, int *val)
+{
+	return vcnl4000_measure(data,
+			VCNL4000_AL_OD, VCNL4000_AL_RDY,
+			VCNL4000_AL_RESULT_HI, val);
+}
+
+static int vcnl4000_measure_proximity(struct vcnl4000_data *data, int *val)
+{
+	return vcnl4000_measure(data,
+			VCNL4000_PS_OD, VCNL4000_PS_RDY,
+			VCNL4000_PS_RESULT_HI, val);
+}
+
+static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
+	[VCNL4000] = {
+		.prod = "VCNL4000",
+		.init = vcnl4000_init,
+		.measure_light = vcnl4000_measure_light,
+		.measure_proximity = vcnl4000_measure_proximity,
+	},
+};
+
 static const struct iio_chan_spec vcnl4000_channels[] = {
 	{
 		.type = IIO_LIGHT,
@@ -125,16 +181,12 @@ static int vcnl4000_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_RAW:
 		switch (chan->type) {
 		case IIO_LIGHT:
-			ret = vcnl4000_measure(data,
-				VCNL4000_AL_OD, VCNL4000_AL_RDY,
-				VCNL4000_AL_RESULT_HI, val);
+			ret = data->chip_spec->measure_light(data, val);
 			if (ret < 0)
 				return ret;
 			return IIO_VAL_INT;
 		case IIO_PROXIMITY:
-			ret = vcnl4000_measure(data,
-				VCNL4000_PS_OD, VCNL4000_PS_RDY,
-				VCNL4000_PS_RESULT_HI, val);
+			ret = data->chip_spec->measure_proximity(data, val);
 			if (ret < 0)
 				return ret;
 			return IIO_VAL_INT;
@@ -146,7 +198,7 @@ static int vcnl4000_read_raw(struct iio_dev *indio_dev,
 			return -EINVAL;
 
 		*val = 0;
-		*val2 = 250000;
+		*val2 = data->al_scale;
 		return IIO_VAL_INT_PLUS_MICRO;
 	default:
 		return -EINVAL;
@@ -162,7 +214,7 @@ static int vcnl4000_probe(struct i2c_client *client,
 {
 	struct vcnl4000_data *data;
 	struct iio_dev *indio_dev;
-	int ret, prod_id;
+	int ret;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (!indio_dev)
@@ -171,19 +223,16 @@ static int vcnl4000_probe(struct i2c_client *client,
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
+	data->id = id->driver_data;
+	data->chip_spec = &vcnl4000_chip_spec_cfg[data->id];
 	mutex_init(&data->lock);
 
-	ret = i2c_smbus_read_byte_data(data->client, VCNL4000_PROD_REV);
+	ret = data->chip_spec->init(data);
 	if (ret < 0)
 		return ret;
 
-	prod_id = ret >> 4;
-	if (prod_id != VCNL4010_ID && prod_id != VCNL4000_ID)
-		return -ENODEV;
-
 	dev_dbg(&client->dev, "%s Ambient light/proximity sensor, Rev: %02x\n",
-		(prod_id == VCNL4010_ID) ? "VCNL4010/4020" : "VCNL4000",
-		ret & 0xf);
+		data->chip_spec->prod, data->rev);
 
 	indio_dev->dev.parent = &client->dev;
 	indio_dev->info = &vcnl4000_info;