iio: dac: ad5413: Integrate reviewer feedback

This patch addresses various improvements based on reviewer suggestions:

- Removed unused index variable in parse_dt()
- Fixed misleading indentation in probe() conditional blocks
- Reworked DT bindings: switched to enum/oneOf and restricted voltage/current ranges
- Added driver-side range validation for voltage and current modes
- Replaced manual bit macros with FIELD_PREP() for DAC_CONFIG
- Removed unnecessary include: <linux/kernel.h>
- Sorted entries in Kconfig and Makefile
- Quoted DT required property names and simplified mutual-exclusion logic
- Tidied up whitespace, blank lines, and long lines

Signed-off-by: Bruce Tsao <bruce.tsao@analog.com>

iio: dac: ad5413: apply reviewer cleanups

Address various reviewer comments and style fixes:

- Move FIELD_PREP mask definitions directly beneath their register defines
- Replace usleep_range() with fsleep() in wait loops
- Return -ETIMEDOUT on timeout instead of -EIO
- Use dev_err_probe() for probe-time failures in DT parsing
- Rename ad5413_find_closest_match() to ad5413_find_best_match()
- Change out_range to a pointer to avoid per-field copies
- Guard devm_mutex_init() with kernel version check; fall back to mutex_init()
- Remove redundant comments and simplify error paths
- Simplify pwr_down logic with ternary assignment
- Fix indentation, tab/space usage, and other style issues as per checkpatch

Signed-off-by: Bruce Tsao <bruce.tsao@analog.com>

iio: dac: ad5413: final cleanups after style check

Address remaining checkpatch warnings:
 - remove trailing '('
 - adjust CamelCase enum name
 - fix unnecessary parentheses

Signed-off-by: Bruce Tsao <bruce.tsao@analog.com>

Author: BruceTsaoADI

Documentation/devicetree/bindings/iio/dac/adi,ad5413.yaml

@@ -21,18 +21,20 @@ properties:
 
   adi,range-microvolt:
     description: Voltage output range <min, max> in microvolts
-    enum:
-      - [-10500000, 10500000]
-      - [-12600000, 12600000]
+    oneOf:
+      - items:
+          - const: -10500000
+          - const: 10500000
 
   adi,range-microamp:
     description: Current output range <min, max> in microamps
-    enum:
-      - [0, 24000]
+    oneOf:
+      - items:
+          - const: 0
+          - const: 24000
 
   adi,slew-time-us:
-    description: |
-      Output digital slew control time in microseconds
+    description: Output digital slew control time in microseconds
     minimum: 0
     maximum: 1000000
 
@@ -43,17 +45,10 @@ required:
 
 allOf:
   - $ref: /schemas/spi/spi-peripheral-props.yaml#
-  - if:
-      required: [adi, range-microamp]
-    then:
-      properties:
-        adi,range-microvolt: false
-  - if:
-      required: [adi, range-microvolt]
-    then:
-      properties:
-        adi,range-microamp: false
-
+  - oneOf:
+      - required: ['adi,range-microamp']
+      - required: ['adi,range-microvolt']
+    
 unevaluatedProperties: false
 
 examples:

drivers/iio/dac/Kconfig

@@ -94,6 +94,16 @@ config AD5380
 	  To compile this driver as module choose M here: the module will be called
 	  ad5380.
 
+config AD5413
+	tristate "Analog Devices AD5413 DAC driver"
+	depends on SPI_MASTER
+	help
+	  Say yes here to build support for Analog Devices AD5413 single channel
+	  Digital to Analog Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5758.
+
 config AD5421
 	tristate "Analog Devices AD5421 DAC driver"
 	depends on SPI
@@ -563,14 +573,4 @@ config VF610_DAC
 
 	  This driver can also be built as a module. If so, the module will
 	  be called vf610_dac.
-
-config AD5413
-	tristate "Analog Devices AD5413 DAC driver"
-	depends on SPI_MASTER
-	help
-	  Say yes here to build support for Analog Devices AD5413 single channel
-	  Digital to Analog Converter.
-
-	  To compile this driver as a module, choose M here: the
-	  module will be called ad5758.
 endmenu

drivers/iio/dac/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_AD3552R) += ad3552r.o
 obj-$(CONFIG_AD5270) += ad5270.o
 obj-$(CONFIG_AD5360) += ad5360.o
 obj-$(CONFIG_AD5380) += ad5380.o
+obj-$(CONFIG_AD5413) += ad5413.o
 obj-$(CONFIG_AD5421) += ad5421.o
 obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
 obj-$(CONFIG_AD5064) += ad5064.o
@@ -57,4 +58,4 @@ obj-$(CONFIG_TI_DAC5571) += ti-dac5571.o
 obj-$(CONFIG_TI_DAC7311) += ti-dac7311.o
 obj-$(CONFIG_TI_DAC7612) += ti-dac7612.o
 obj-$(CONFIG_VF610_DAC) += vf610_dac.o
-obj-$(CONFIG_AD5413) += ad5413.o
+