iio:adc128s052: add support for adc122s021

Signed-off-by: Urs Fässler <urs.fassler@bytesatwork.ch>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Documentation/devicetree/bindings/iio/adc/ti-adc128s052.txt

-* Texas Instruments' ADC128S052 ADC chip
+* Texas Instruments' ADC128S052 and ADC122S021 ADC chip
 
 Required properties:
- - compatible: Should be "ti,adc128s052"
+ - compatible: Should be "ti,adc128s052" or "ti,adc122s021"
  - reg: spi chip select number for the device
  - vref-supply: The regulator supply for ADC reference voltage
 

drivers/iio/adc/Kconfig

@@ -292,11 +292,11 @@ config TI_ADC081C
 	  called ti-adc081c.
 
 config TI_ADC128S052
-	tristate "Texas Instruments ADC128S052"
+	tristate "Texas Instruments ADC128S052/ADC122S021"
 	depends on SPI
 	help
 	  If you say yes here you get support for Texas Instruments ADC128S052
-	  chip.
+	  and ADC122S021 chips.
 
 	  This driver can also be built as a module. If so, the module will be
 	  called ti-adc128s052.

drivers/iio/adc/ti-adc128s052.c

 /*
  * Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com>
  *
- * Driver for Texas Instruments' ADC128S052 ADC chip.
- * Datasheet can be found here:
+ * Driver for Texas Instruments' ADC128S052 and ADC122S021 ADC chip.
+ * Datasheets can be found here:
  * http://www.ti.com/lit/ds/symlink/adc128s052.pdf
+ * http://www.ti.com/lit/ds/symlink/adc122s021.pdf
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -16,6 +17,11 @@
 #include <linux/iio/iio.h>
 #include <linux/regulator/consumer.h>
 
+struct adc128_configuration {
+	const struct iio_chan_spec	*channels;
+	u8				num_channels;
+};
+
 struct adc128 {
 	struct spi_device *spi;
 
@@ -92,7 +98,7 @@ static int adc128_read_raw(struct iio_dev *indio_dev,
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
 	}
 
-static const struct iio_chan_spec adc128_channels[] = {
+static const struct iio_chan_spec adc128s052_channels[] = {
 	ADC128_VOLTAGE_CHANNEL(0),
 	ADC128_VOLTAGE_CHANNEL(1),
 	ADC128_VOLTAGE_CHANNEL(2),
@@ -103,6 +109,16 @@ static const struct iio_chan_spec adc128_channels[] = {
 	ADC128_VOLTAGE_CHANNEL(7),
 };
 
+static const struct iio_chan_spec adc122s021_channels[] = {
+	ADC128_VOLTAGE_CHANNEL(0),
+	ADC128_VOLTAGE_CHANNEL(1),
+};
+
+static const struct adc128_configuration adc128_config[] = {
+	{ adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
+	{ adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
+};
+
 static const struct iio_info adc128_info = {
 	.read_raw = adc128_read_raw,
 	.driver_module = THIS_MODULE,
@@ -112,6 +128,7 @@ static int adc128_probe(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev;
 	struct adc128 *adc;
+	int config = spi_get_device_id(spi)->driver_data;
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
@@ -128,8 +145,8 @@ static int adc128_probe(struct spi_device *spi)
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &adc128_info;
 
-	indio_dev->channels = adc128_channels;
-	indio_dev->num_channels = ARRAY_SIZE(adc128_channels);
+	indio_dev->channels = adc128_config[config].channels;
+	indio_dev->num_channels = adc128_config[config].num_channels;
 
 	adc->reg = devm_regulator_get(&spi->dev, "vref");
 	if (IS_ERR(adc->reg))
@@ -158,7 +175,8 @@ static int adc128_remove(struct spi_device *spi)
 }
 
 static const struct spi_device_id adc128_id[] = {
-	{ "adc128s052", 0},
+	{ "adc128s052", 0},	/* index into adc128_config */
+	{ "adc122s021",	1},
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, adc128_id);