staging:iio:ad7780: Add support for the ad7170/ad7171

The ad7170/ad7171 have a software interface similar to the ad7780. They do not
have an external pin which allows to change the internal gain and the what is
used for the gain bit in the ad7780/ad7781 becomes part of the check pattern.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

drivers/staging/iio/adc/Kconfig

@@ -82,12 +82,12 @@ config AD7887
 	  module will be called ad7887.
 
 config AD7780
-	tristate "Analog Devices AD7780 AD7781 ADC driver"
+	tristate "Analog Devices AD7780 and similar ADCs driver"
 	depends on SPI
 	depends on GPIOLIB
 	select AD_SIGMA_DELTA
 	help
-	  Say yes here to build support for Analog Devices
+	  Say yes here to build support for Analog Devices AD7170, AD7171,
 	  AD7780 and AD7781 SPI analog to digital converters (ADC).
 	  If unsure, say N (but it's safe to say "Y").
 

drivers/staging/iio/adc/ad7780.c

 /*
- * AD7780/AD7781 SPI ADC driver
+ * AD7170/AD7171 and AD7780/AD7781 SPI ADC driver
  *
  * Copyright 2011 Analog Devices Inc.
  *
@@ -34,7 +34,9 @@
 #define AD7780_PAT0	(1 << 0)
 
 struct ad7780_chip_info {
-	struct iio_chan_spec		channel;
+	struct iio_chan_spec	channel;
+	unsigned int		pattern_mask;
+	unsigned int		pattern;
 };
 
 struct ad7780_state {
@@ -48,6 +50,8 @@ struct ad7780_state {
 };
 
 enum ad7780_supported_device_ids {
+	ID_AD7170,
+	ID_AD7171,
 	ID_AD7780,
 	ID_AD7781,
 };
@@ -109,9 +113,10 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
 	unsigned int raw_sample)
 {
 	struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
+	const struct ad7780_chip_info *chip_info = st->chip_info;
 
 	if ((raw_sample & AD7780_ERR) ||
-		!((raw_sample & AD7780_PAT0) && !(raw_sample & AD7780_PAT1)))
+		((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
 		return -EIO;
 
 	if (raw_sample & AD7780_GAIN)
@@ -128,12 +133,29 @@ static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
 	.has_registers = false,
 };
 
+#define AD7780_CHANNEL(bits, wordsize) \
+	AD_SD_CHANNEL(1, 0, 0, bits, 32, wordsize - bits)
+
 static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
+	[ID_AD7170] = {
+		.channel = AD7780_CHANNEL(12, 24),
+		.pattern = 0x5,
+		.pattern_mask = 0x7,
+	},
+	[ID_AD7171] = {
+		.channel = AD7780_CHANNEL(16, 24),
+		.pattern = 0x5,
+		.pattern_mask = 0x7,
+	},
 	[ID_AD7780] = {
-		.channel = AD_SD_CHANNEL(1, 0, 0, 24, 32, 8),
+		.channel = AD7780_CHANNEL(24, 32),
+		.pattern = 0x1,
+		.pattern_mask = 0x3,
 	},
 	[ID_AD7781] = {
-		.channel = AD_SD_CHANNEL(1, 0, 0, 20, 32, 12),
+		.channel = AD7780_CHANNEL(20, 32),
+		.pattern = 0x1,
+		.pattern_mask = 0x3,
 	},
 };
 
@@ -247,6 +269,8 @@ static int __devexit ad7780_remove(struct spi_device *spi)
 }
 
 static const struct spi_device_id ad7780_id[] = {
+	{"ad7170", ID_AD7170},
+	{"ad7171", ID_AD7171},
 	{"ad7780", ID_AD7780},
 	{"ad7781", ID_AD7781},
 	{}
@@ -265,5 +289,5 @@ static struct spi_driver ad7780_driver = {
 module_spi_driver(ad7780_driver);
 
 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
-MODULE_DESCRIPTION("Analog Devices AD7780/1 ADC");
+MODULE_DESCRIPTION("Analog Devices AD7780 and similar ADCs");
 MODULE_LICENSE("GPL v2");