iio: dac: ad3552r-common: fix ad3541/2r ranges

Fix ad3541/2r voltage ranges to be as per ad3542r datasheet,
rev. C, table 38 (page 57).

The wrong ad354xr ranges was generating erroneous Vpp output.

In more details:
- fix wrong number of ranges, they are 5 ranges, not 6,
- remove non-existent 0-3V range,
- adjust order, since ad3552r_find_range() get a wrong index,
  producing a wrong Vpp as output.

Retested all the ranges on real hardware, EVALAD3542RFMCZ:

adi,output-range-microvolt (fdt):
<(000000) (2500000)>;   ok (Rfbx1, switch 10)
<(000000) (5000000)>;   ok (Rfbx1, switch 10)
<(000000) (10000000)>;  ok (Rfbx1, switch 10)
<(-5000000) (5000000)>; ok (Rfbx2, switch +/- 5)
<(-2500000) (7500000)>; ok (Rfbx2, switch -2.5/7.5)

Fixes: 8f2b548 ("drivers:iio:dac: Add AD3552R driver support")
Signed-off-by: Angelo Dureghello <[email protected]>
Reviewed-by: David Lechner <[email protected]>
Link: https://patch.msgid.link/20250108-wip-bl-ad3552r-axi-v0-iio-testing-carlos-v2-1-2dac02f04638@baylibre.com
Cc: <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

Author: spectrum70

drivers/iio/dac/ad3552r-common.c

@@ -22,11 +22,10 @@ EXPORT_SYMBOL_NS_GPL(ad3552r_ch_ranges, "IIO_AD3552R");
 
 const s32 ad3542r_ch_ranges[AD3542R_MAX_RANGES][2] = {
 	[AD3542R_CH_OUTPUT_RANGE_0__2P5V]	= { 0, 2500 },
-	[AD3542R_CH_OUTPUT_RANGE_0__3V]		= { 0, 3000 },
 	[AD3542R_CH_OUTPUT_RANGE_0__5V]		= { 0, 5000 },
 	[AD3542R_CH_OUTPUT_RANGE_0__10V]	= { 0, 10000 },
-	[AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V]	= { -2500, 7500 },
-	[AD3542R_CH_OUTPUT_RANGE_NEG_5__5V]	= { -5000, 5000 }
+	[AD3542R_CH_OUTPUT_RANGE_NEG_5__5V]	= { -5000, 5000 },
+	[AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V]	= { -2500, 7500 }
 };
 EXPORT_SYMBOL_NS_GPL(ad3542r_ch_ranges, "IIO_AD3552R");
 

drivers/iio/dac/ad3552r.h

@@ -131,7 +131,7 @@
 #define AD3552R_CH1_ACTIVE				BIT(1)
 
 #define AD3552R_MAX_RANGES	5
-#define AD3542R_MAX_RANGES	6
+#define AD3542R_MAX_RANGES	5
 #define AD3552R_QUAD_SPI	2
 
 extern const s32 ad3552r_ch_ranges[AD3552R_MAX_RANGES][2];
@@ -189,16 +189,14 @@ enum ad3552r_ch_vref_select {
 enum ad3542r_ch_output_range {
 	/* Range from 0 V to 2.5 V. Requires Rfb1x connection */
 	AD3542R_CH_OUTPUT_RANGE_0__2P5V,
-	/* Range from 0 V to 3 V. Requires Rfb1x connection  */
-	AD3542R_CH_OUTPUT_RANGE_0__3V,
 	/* Range from 0 V to 5 V. Requires Rfb1x connection  */
 	AD3542R_CH_OUTPUT_RANGE_0__5V,
 	/* Range from 0 V to 10 V. Requires Rfb2x connection  */
 	AD3542R_CH_OUTPUT_RANGE_0__10V,
-	/* Range from -2.5 V to 7.5 V. Requires Rfb2x connection  */
-	AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V,
 	/* Range from -5 V to 5 V. Requires Rfb2x connection  */
 	AD3542R_CH_OUTPUT_RANGE_NEG_5__5V,
+	/* Range from -2.5 V to 7.5 V. Requires Rfb2x connection  */
+	AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V,
 };
 
 enum ad3552r_ch_output_range {