[PATCH 2/2] iio: mxs-lradc: add ADC channel 9 as a copy of channel 8

[Robert Hodaszi <robert.hodaszi@digi.com>]

Commit c8231a9af8147f8a401fc55931ec44abfb937660 ("iio: mxs-lradc: compute
temperature from channel 8 and 9") merged channel 8 and channel 9 to create an
IIO_TEMP channel. It changed the number of LRADC channels, which could cause
incompatibility with previous device-tree declarations, and also makes it
illogical (e.g. channel 15 is <&lradc 14>).

Add channel 9 as a copy of channel 8. Reading channel 9 has the same output as
reading channel 8.

Signed-off-by: Robert Hodaszi <robert.hodaszi@digi.com>
---
 drivers/staging/iio/adc/mxs-lradc.c | 61 +++++++++++++++++++++----------------
 1 file changed, 35 insertions(+), 26 deletions(-)

diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
index 52d7517..25c0519 100644
--- a/drivers/staging/iio/adc/mxs-lradc.c
+++ b/drivers/staging/iio/adc/mxs-lradc.c
@@ -1376,8 +1376,8 @@ static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
  * Driver initialization
  */
 
-#define MXS_ADC_CHAN(idx, chan_type) {				\
-	.type = (chan_type),					\
+#define MXS_ADC_VOLTAGE_CHAN(idx) {				\
+	.type = IIO_VOLTAGE,					\
 	.indexed = 1,						\
 	.scan_index = (idx),					\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
@@ -1391,32 +1391,41 @@ static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
 	},							\
 }
 
+#define MXS_ADC_TEMP_CHAN(idx) {				\
+	.type = IIO_TEMP,					\
+	.indexed = 1,						\
+	.scan_index = (idx),					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
+			      BIT(IIO_CHAN_INFO_SCALE) |	\
+			      BIT(IIO_CHAN_INFO_OFFSET),	\
+	.channel = (idx),					\
+	.address = (idx),					\
+	.scan_type = {						\
+		.sign = 'u',					\
+		.realbits = 18,					\
+		.storagebits = 32,				\
+	},							\
+}
+
 static const struct iio_chan_spec mxs_lradc_chan_spec[] = {
-	MXS_ADC_CHAN(0, IIO_VOLTAGE),
-	MXS_ADC_CHAN(1, IIO_VOLTAGE),
-	MXS_ADC_CHAN(2, IIO_VOLTAGE),
-	MXS_ADC_CHAN(3, IIO_VOLTAGE),
-	MXS_ADC_CHAN(4, IIO_VOLTAGE),
-	MXS_ADC_CHAN(5, IIO_VOLTAGE),
-	MXS_ADC_CHAN(6, IIO_VOLTAGE),
-	MXS_ADC_CHAN(7, IIO_VOLTAGE),	/* VBATT */
+	MXS_ADC_VOLTAGE_CHAN(0),
+	MXS_ADC_VOLTAGE_CHAN(1),
+	MXS_ADC_VOLTAGE_CHAN(2),
+	MXS_ADC_VOLTAGE_CHAN(3),
+	MXS_ADC_VOLTAGE_CHAN(4),
+	MXS_ADC_VOLTAGE_CHAN(5),
+	MXS_ADC_VOLTAGE_CHAN(6),
+	MXS_ADC_VOLTAGE_CHAN(7),	/* VBATT */
 	/* Combined Temperature sensors */
-	{
-		.type = IIO_TEMP,
-		.indexed = 1,
-		.scan_index = 8,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
-				      BIT(IIO_CHAN_INFO_OFFSET) |
-				      BIT(IIO_CHAN_INFO_SCALE),
-		.channel = 8,
-		.scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
-	},
-	MXS_ADC_CHAN(10, IIO_VOLTAGE),	/* VDDIO */
-	MXS_ADC_CHAN(11, IIO_VOLTAGE),	/* VTH */
-	MXS_ADC_CHAN(12, IIO_VOLTAGE),	/* VDDA */
-	MXS_ADC_CHAN(13, IIO_VOLTAGE),	/* VDDD */
-	MXS_ADC_CHAN(14, IIO_VOLTAGE),	/* VBG */
-	MXS_ADC_CHAN(15, IIO_VOLTAGE),	/* VDD5V */
+	MXS_ADC_TEMP_CHAN(8),
+	/* CH 9 is the same as CH 8. Declared to fix following channel indexes */
+	MXS_ADC_TEMP_CHAN(9),
+	MXS_ADC_VOLTAGE_CHAN(10),	/* VDDIO */
+	MXS_ADC_VOLTAGE_CHAN(11),	/* VTH */
+	MXS_ADC_VOLTAGE_CHAN(12),	/* VDDA */
+	MXS_ADC_VOLTAGE_CHAN(13),	/* VDDD */
+	MXS_ADC_VOLTAGE_CHAN(14),	/* VBG */
+	MXS_ADC_VOLTAGE_CHAN(15),	/* VDD5V */
 };
 
 static int mxs_lradc_hw_init(struct mxs_lradc *lradc)