[PATCH v9 0/9] ADF41513/ADF41510 PLL frequency synthesizers

[PATCH v9 0/9] ADF41513/ADF41510 PLL frequency synthesizers

[Rodrigo Alencar via B4 Relay]

This patch series adds support for the Analog Devices ADF41513 and ADF41510
ultralow noise PLL frequency synthesizers. These devices are designed for
implementing local oscillators (LOs) in high-frequency applications.
The ADF41513 covers frequencies from 1 GHz to 26.5 GHz, while the ADF41510
operates from 1 GHz to 10 GHz.

Key features supported by this driver:
- Integer-N and fractional-N operation modes
- High maximum PFD frequency (250 MHz integer-N, 125 MHz fractional-N)
- 25-bit fixed modulus or 49-bit variable modulus fractional modes
- Digital lock detect functionality
- Phase resync capability for consistent output phase
- Load Enable vs Reference signal syncronization

The series includes:
1. PLL driver implementation
2. Device tree bindings documentation
3. IIO ABI documentation

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
Changes in v9:
- Expose simple_strntoull() in a safer prototype instead of new kstrntoull()
- Link to v8: https://lore.kernel.org/r/20260303-adf41513-iio-driver-v8-0-8dd2417cc465@analog.com

Changes in v8:
- Add new function kstrntoull() to lib/kstrtox.c and tests to lib/test-kstrtox.c.
- Drop custom iio u64 parser, replacing it for kstrntoull().
- Dedicated MAINTAINERS entry for drivers/iio/test/iio-test-fixpoint-parse.c.
- Link to v7: https://lore.kernel.org/r/20260216-adf41513-iio-driver-v7-0-b0ed387ab559@analog.com

Changes in v7:
- Addressed minor suggestions.
- frequency_resolution ABI for AD4350 removed in favor of generic one.
- Link to v6: https://lore.kernel.org/r/20260130-adf41513-iio-driver-v6-0-cf46239026bc@analog.com

Changes in v6:
- Drop usage of simple_strtoull().
- Implement better overflow checks with iio_safe_strntou64().
- Link to v5: https://lore.kernel.org/r/20260123-adf41513-iio-driver-v5-0-2dce812a2dda@analog.com

Changes in v5:
- Drop local parsing of 64-bit plus fractional parts
- Add iio_str_to_fixpoint64() to iio core with parsing tests
- Add DT property dependency for adi,charge-pump-resistor-ohms
- Add local definition for ADF41513_HZ_PER_GHZ and drop units.h patch
- Link to v4: https://lore.kernel.org/r/20260116-adf41513-iio-driver-v4-0-dbb7d6782217@analog.com

Changes in v4:
- Proper usage of units.h macros
- Simplifications to DT property parsing
- Adjustments to return value handling
- Drop of simple DT property node example
- Link to v3: https://lore.kernel.org/r/20260108-adf41513-iio-driver-v3-0-23d1371aef48@analog.com

Changes in v3:
- Use FIELD_MODIFY macro in driver implementation
- Drop refin_frequency iio attribute
- Drop muxout-select property from dt-bindings (and rename logic-level property)
- Use -mhz suffix in power-up frequency property
- Address documentation issues
- Link to v2: https://lore.kernel.org/r/20251219-adf41513-iio-driver-v2-0-be29a83d5793@analog.com

Changes in v2:
- separate driver implementation from extra features and improve commit messages
- use macros from units.h
- explanation of custom parse function: adf41513_parse_uhz
- reorganize driver data structures
- drop clock framework support for now
- reorganize documentation
- Link to v1: https://lore.kernel.org/r/20251110-adf41513-iio-driver-v1-0-2df8be0fdc6e@analog.com

---
Rodrigo Alencar (9):
      dt-bindings: iio: frequency: add adf41513
      lib: vsprintf: export simple_strntoull() in a safe prototype
      iio: core: add fixed point parsing with 64-bit parts
      iio: test: add kunit test for fixed-point parsing
      iio: frequency: adf41513: driver implementation
      iio: frequency: adf41513: handle LE synchronization feature
      iio: frequency: adf41513: features on frequency change
      docs: iio: add documentation for adf41513 driver
      Documentation: ABI: testing: add common ABI file for iio/frequency

 Documentation/ABI/testing/sysfs-bus-iio-frequency  |   11 +
 .../ABI/testing/sysfs-bus-iio-frequency-adf4350    |   10 -
 .../bindings/iio/frequency/adi,adf41513.yaml       |  215 ++++
 Documentation/iio/adf41513.rst                     |  199 ++++
 Documentation/iio/index.rst                        |    1 +
 MAINTAINERS                                        |   15 +
 drivers/iio/frequency/Kconfig                      |   10 +
 drivers/iio/frequency/Makefile                     |    1 +
 drivers/iio/frequency/adf41513.c                   | 1240 ++++++++++++++++++++
 drivers/iio/industrialio-core.c                    |  165 ++-
 drivers/iio/test/Kconfig                           |   12 +
 drivers/iio/test/Makefile                          |    1 +
 drivers/iio/test/iio-test-fixpoint-parse.c         |  470 ++++++++
 include/linux/iio/iio.h                            |    2 +
 include/linux/kstrtox.h                            |    4 +
 lib/vsprintf.c                                     |   59 +-
 16 files changed, 2346 insertions(+), 69 deletions(-)
---
base-commit: ff0843ceb1fb11a6b73e0e77b932ef7967aecd4b
change-id: 20251110-adf41513-iio-driver-aaca8a7f808e

Best regards,
-- 
Rodrigo Alencar <rodrigo.alencar@analog.com>

[PATCH v9 1/9] dt-bindings: iio: frequency: add adf41513

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

DT-bindings for ADF41513, an ultralow noise PLL frequency synthesizer that
can be used to implement local oscillators (LOs) as high as 26.5 GHz.
Some properties are based upon an existing PLL device properties
(e.g. ADF4350).

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 .../bindings/iio/frequency/adi,adf41513.yaml       | 215 +++++++++++++++++++++
 MAINTAINERS                                        |   7 +
 2 files changed, 222 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/frequency/adi,adf41513.yaml b/Documentation/devicetree/bindings/iio/frequency/adi,adf41513.yaml
new file mode 100644
index 000000000000..2d09cb94b6ff
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/frequency/adi,adf41513.yaml
@@ -0,0 +1,215 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/frequency/adi,adf41513.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices ADF41513 PLL Frequency Synthesizer
+
+maintainers:
+  - Rodrigo Alencar <rodrigo.alencar@analog.com>
+
+description:
+  The ADF41513 is an ultralow noise frequency synthesizer that can be used to
+  implement local oscillators (LOs) as high as 26.5 GHz in the upconversion and
+  downconversion sections of wireless receivers and transmitters. The ADF41510
+  supports frequencies up to 10 GHz.
+
+  https://www.analog.com/en/products/adf41510.html
+  https://www.analog.com/en/products/adf41513.html
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - adi,adf41510
+      - adi,adf41513
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 25000000
+
+  clocks:
+    maxItems: 1
+    description: Clock that provides the reference input frequency.
+
+  avdd1-supply:
+    description: PFD and Up and Down Digital Driver Power Supply (3.3 V)
+
+  avdd2-supply:
+    description: RF Buffer and Prescaler Power Supply (3.3 V)
+
+  avdd3-supply:
+    description: N Divider Power Supply (3.3 V)
+
+  avdd4-supply:
+    description: R Divider and Lock Detector Power Supply (3.3 V)
+
+  avdd5-supply:
+    description: Sigma-Delta Modulator and SPI Power Supply (3.3 V)
+
+  vp-supply:
+    description: Charge Pump Power Supply (3.3 V)
+
+  enable-gpios:
+    description:
+      GPIO that controls the chip enable pin. A logic low on this pin
+      powers down the device and puts the charge pump output into
+      three-state mode.
+    maxItems: 1
+
+  lock-detect-gpios:
+    description:
+      GPIO for lock detect functionality. When configured for digital lock
+      detect, this pin will output a logic high when the PLL is locked.
+    maxItems: 1
+
+  adi,power-up-frequency-mhz:
+    minimum: 1000
+    maximum: 26500
+    default: 10000
+    description:
+      The PLL tunes to this frequency during the initialization sequence.
+      This property should be set to a frequency supported by the loop filter
+      and VCO used in the design. Range is 1 GHz to 26.5 GHz for ADF41513,
+      and 1 GHz to 10 GHz for ADF41510.
+
+  adi,reference-div-factor:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 32
+    default: 1
+    description:
+      Value for the reference division factor (R Counter). The driver will
+      increment R Counter as needed to achieve a PFD frequency within the
+      allowed range. High R counter values will reduce the PFD frequency, which
+      lowers the frequency resolution, and affects phase noise performance.
+      As it affects the PFD frequency, this value depends on the loop filter
+      design.
+
+  adi,reference-doubler-enable:
+    description:
+      Enables the reference doubler when deriving the PFD frequency.
+      The maximum reference frequency when the doubler is enabled is 225 MHz.
+      As it affects the PFD frequency, this value depends on the loop filter
+      design.
+    type: boolean
+
+  adi,reference-div2-enable:
+    description:
+      Enables the reference divide-by-2 function when deriving the PFD
+      frequency. As it affects the PFD frequency, this value depends on the
+      loop filter design.
+    type: boolean
+
+  adi,charge-pump-resistor-ohms:
+    minimum: 1800
+    maximum: 10000
+    default: 2700
+    description:
+      External charge pump resistor (R_SET) value in ohms. This sets the maximum
+      charge pump current along with the charge pump current setting.
+
+  adi,charge-pump-current-microamp:
+    description:
+      Charge pump current (I_CP) in microamps. The value will be rounded to the
+      nearest supported value. Range of acceptable values depends on the
+      charge pump resistor value, such that 810 mV <= I_CP * R_SET <= 12960 mV.
+      This value depends on the loop filter and the VCO design.
+
+  adi,logic-level-1v8-enable:
+    description:
+      Set MUXOUT and DLD logic levels to 1.8V. Default is 3.3V.
+    type: boolean
+
+  adi,phase-detector-polarity-positive-enable:
+    description:
+      Set phase detector polarity to positive. Default is negative.
+      Use positive polarity with non-inverting loop filter and VCO with
+      positive tuning slope, or with inverting loop filter and VCO with
+      negative tuning slope.
+    type: boolean
+
+  adi,lock-detector-count:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 64
+    description:
+      Sets the value for Lock Detector count of the PLL, which determines the
+      number of consecutive phase detector cycles that must be within the lock
+      detector window before lock is declared. Lower values increase the lock
+      detection sensitivity, while higher values provides a more stable lock
+      detection. Applications that consume the lock detect signal may require
+      different settings based on system requirements.
+    enum: [2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192]
+
+  adi,phase-resync-period-ns:
+    default: 0
+    description:
+      When this value is non-zero, enable phase resync functionality, which
+      produces a consistent output phase offset with respect to the input
+      reference. The value specifies the resync period in nanoseconds, used
+      to configure clock dividers with respect to the PFD frequency. This value
+      should be set to a value that is at least as long as the worst case lock
+      time, i.e., it depends mostly on the loop filter design.
+
+  adi,le-sync-enable:
+    description:
+      Synchronizes Load Enable (LE) transitions with the reference signal to
+      avoid asynchronous glitches in the output. This is recommended when using
+      the PLL as a frequency synthesizer, where the reference signal will always
+      be present while the device is being configured. When using the PLL as a
+      frequency tracker, where the reference signal may be absent, LE sync
+      should be left disabled.
+    type: boolean
+
+dependencies:
+  adi,charge-pump-resistor-ohms: [ 'adi,charge-pump-current-microamp' ]
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - avdd1-supply
+  - avdd2-supply
+  - avdd3-supply
+  - avdd4-supply
+  - avdd5-supply
+  - vp-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        pll@0 {
+            compatible = "adi,adf41513";
+            reg = <0>;
+            spi-max-frequency = <25000000>;
+            clocks = <&ref_clk>;
+            avdd1-supply = <&avdd1_3v3>;
+            avdd2-supply = <&avdd2_3v3>;
+            avdd3-supply = <&avdd3_3v3>;
+            avdd4-supply = <&avdd4_3v3>;
+            avdd5-supply = <&avdd5_3v3>;
+            vp-supply = <&vp_3v3>;
+            enable-gpios = <&gpio0 10 GPIO_ACTIVE_HIGH>;
+            lock-detect-gpios = <&gpio0 11 GPIO_ACTIVE_HIGH>;
+
+            adi,power-up-frequency-mhz = <15500>;
+            adi,charge-pump-current-microamp = <3600>;
+            adi,charge-pump-resistor-ohms = <2700>;
+            adi,reference-doubler-enable;
+            adi,lock-detector-count = <64>;
+            adi,phase-resync-period-ns = <0>;
+            adi,phase-detector-polarity-positive-enable;
+            adi,le-sync-enable;
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 08d8ddf4ef68..e3568f08ea55 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1654,6 +1654,13 @@ W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/adc/adi,ade9000.yaml
 F:	drivers/iio/adc/ade9000.c
 
+ANALOG DEVICES INC ADF41513 DRIVER
+M:	Rodrigo Alencar <rodrigo.alencar@analog.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/iio/frequency/adi,adf41513.yaml
+
 ANALOG DEVICES INC ADF4377 DRIVER
 M:	Antoniu Miclaus <antoniu.miclaus@analog.com>
 L:	linux-iio@vger.kernel.org

-- 
2.43.0

[PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

Expose simple_strntoull(), by addressing its FIXME, i.e. its prototype is
slightly changed so that -ERANGE or -EINVAL can be evaluated by the user.
Flow of the function is not changed and error value is returned in the
end. Unsafe internal wrapper is created to reduce amount of changes.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 include/linux/kstrtox.h |  4 ++++
 lib/vsprintf.c          | 59 +++++++++++++++++++++++++++++++++++++++++--------
 2 files changed, 54 insertions(+), 9 deletions(-)

diff --git a/include/linux/kstrtox.h b/include/linux/kstrtox.h
index 6ea897222af1..5e161073121f 100644
--- a/include/linux/kstrtox.h
+++ b/include/linux/kstrtox.h
@@ -148,4 +148,8 @@ extern long simple_strtol(const char *,char **,unsigned int);
 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 extern long long simple_strtoll(const char *,char **,unsigned int);
 
+extern ssize_t __must_check simple_strntoull(const char *startp, const char **endp,
+					     unsigned int base, size_t max_chars,
+					     unsigned long long *res);
+
 #endif	/* _LINUX_KSTRTOX_H */
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 800b8ac49f53..6fb880f4013b 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -75,25 +75,66 @@ enum hash_pointers_policy {
 };
 static enum hash_pointers_policy hash_pointers_mode __initdata;
 
+/**
+ * simple_strntoull - convert a string to an unsigned long long with a character limit
+ *
+ * @startp: The start of the string
+ * @endp: A pointer to the end of the parsed string will be placed here
+ * @base: The number base to use
+ * @max_chars: The maximum number of characters to parse
+ * @res: Where to write the result of the conversion on success
+ *
+ * Returns amount of processed characters on success, -ERANGE on overflow and
+ * -EINVAL on parsing error.
+ */
 noinline
-static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars)
+ssize_t simple_strntoull(const char *startp, const char **endp,
+			 unsigned int base, size_t max_chars,
+			 unsigned long long *res)
 {
 	const char *cp;
-	unsigned long long result = 0ULL;
 	size_t prefix_chars;
 	unsigned int rv;
+	ssize_t ret;
 
 	cp = _parse_integer_fixup_radix(startp, &base);
 	prefix_chars = cp - startp;
 	if (prefix_chars < max_chars) {
-		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
-		/* FIXME */
+		rv = _parse_integer_limit(cp, base, res, max_chars - prefix_chars);
+		if (rv & KSTRTOX_OVERFLOW)
+			ret = -ERANGE;
+		else if (rv == 0)
+			ret = -EINVAL;
+		else
+			ret = rv + prefix_chars;
 		cp += (rv & ~KSTRTOX_OVERFLOW);
 	} else {
 		/* Field too short for prefix + digit, skip over without converting */
 		cp = startp + max_chars;
+		ret = -EINVAL;
+		*res = 0ULL;
 	}
 
+	if (endp)
+		*endp = cp;
+
+	return ret;
+}
+EXPORT_SYMBOL(simple_strntoull);
+
+/* unsafe_strntoull ignores simple_strntoull() return value and endp const qualifier */
+inline
+static unsigned long long unsafe_strntoull(const char *startp, char **endp,
+					   unsigned int base, size_t max_chars)
+{
+	unsigned long long result;
+	const char *cp;
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-result"
+	simple_strntoull(startp, &cp, base, max_chars, &result);
+#pragma GCC diagnostic pop
+
 	if (endp)
 		*endp = (char *)cp;
 
@@ -111,7 +152,7 @@ static unsigned long long simple_strntoull(const char *startp, char **endp, unsi
 noinline
 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 {
-	return simple_strntoull(cp, endp, base, INT_MAX);
+	return unsafe_strntoull(cp, endp, base, INT_MAX);
 }
 EXPORT_SYMBOL(simple_strtoull);
 
@@ -132,7 +173,7 @@ EXPORT_SYMBOL(simple_strtoul);
 unsigned long simple_strntoul(const char *cp, char **endp, unsigned int base,
 			      size_t max_chars)
 {
-	return simple_strntoull(cp, endp, base, max_chars);
+	return unsafe_strntoull(cp, endp, base, max_chars);
 }
 EXPORT_SYMBOL(simple_strntoul);
 
@@ -163,9 +204,9 @@ static long long simple_strntoll(const char *cp, char **endp, unsigned int base,
 	 * and the content of *cp is irrelevant.
 	 */
 	if (*cp == '-' && max_chars > 0)
-		return -simple_strntoull(cp + 1, endp, base, max_chars - 1);
+		return -unsafe_strntoull(cp + 1, endp, base, max_chars - 1);
 
-	return simple_strntoull(cp, endp, base, max_chars);
+	return unsafe_strntoull(cp, endp, base, max_chars);
 }
 
 /**
@@ -3670,7 +3711,7 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
 			val.s = simple_strntoll(str, &next, base,
 						field_width >= 0 ? field_width : INT_MAX);
 		else
-			val.u = simple_strntoull(str, &next, base,
+			val.u = unsafe_strntoull(str, &next, base,
 						 field_width >= 0 ? field_width : INT_MAX);
 
 		switch (qualifier) {

-- 
2.43.0

[PATCH v9 3/9] iio: core: add fixed point parsing with 64-bit parts

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

Add iio_str_to_fixpoint64() function that leverages simple_strntoull()
to parse numbers from a string. A helper function
__iio_str_to_fixpoint64() replaces __iio_str_to_fixpoint() implementation,
extending its usage for 64-bit fixed-point parsing.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 drivers/iio/industrialio-core.c | 165 ++++++++++++++++++++++++++++------------
 include/linux/iio/iio.h         |   2 +
 2 files changed, 117 insertions(+), 50 deletions(-)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 22eefd048ba9..69cb0355526c 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -881,6 +881,91 @@ static ssize_t iio_read_channel_info_avail(struct device *dev,
 	}
 }
 
+/**
+ * __iio_str_to_fixpoint64() - Parse a fixed-point number from a string
+ * @str: The string to parse
+ * @fract_mult: Multiplier for the first decimal place, should be a power of 10
+ * @integer: The integer part of the number
+ * @fract: The fractional part of the number
+ * @scale_db: True if this should parse as dB
+ *
+ * This variant uses 64-bit integers for both integer and fractional parts.
+ * Parsed positive values greater than S64_MAX are returned as-is. Parsed
+ * negative values less than S64_MIN are treated as range error, so -ERANGE is
+ * returned.
+ *
+ * Returns:
+ * 0 on success, or a negative error code if the string could not be parsed.
+ */
+static int __iio_str_to_fixpoint64(const char *str, u64 fract_mult,
+				   s64 *integer, s64 *fract, bool scale_db)
+{
+	u64 i = 0, f = 0;
+	int precision = ffs(fract_mult);
+	bool negative = false;
+	ssize_t len;
+
+	if (precision > 20) /* ceil(log10(U64_MAX)) = 20 */
+		return -EINVAL;
+
+	if (str[0] == '-') {
+		negative = true;
+		str++;
+	} else if (str[0] == '+') {
+		str++;
+	}
+
+	if (*str != '.') {
+		len = simple_strntoull(str, &str, 10, SIZE_MAX, &i);
+		if (len < 0)
+			return len;
+	}
+
+	if (precision && *str == '.') {
+		str++; /* skip decimal point */
+		len = simple_strntoull(str, &str, 10, precision, &f);
+		if (len < 0)
+			return len;
+
+		if (len < precision) /* scale up */
+			f *= int_pow(10, precision - len);
+
+		while (isdigit(*str)) /* truncate: ignore further digits */
+			str++;
+	}
+
+	if (scale_db) {
+		/* Ignore the dB suffix */
+		if (!strncmp(str, " dB", sizeof(" dB") - 1))
+			str += sizeof(" dB") - 1;
+		else if (!strncmp(str, "dB", sizeof("dB") - 1))
+			str += sizeof("dB") - 1;
+	}
+
+	if (*str == '\n')
+		str++;
+
+	if (*str != '\0')
+		return -EINVAL;
+
+	if (negative) {
+		if (i) {
+			if ((s64)-i > 0)
+				return -ERANGE;
+			i = -i;
+		} else {
+			if ((s64)-f > 0)
+				return -ERANGE;
+			f = -f;
+		}
+	}
+
+	*integer = i;
+	*fract = f;
+
+	return 0;
+}
+
 /**
  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
  * @str: The string to parse
@@ -895,63 +980,43 @@ static ssize_t iio_read_channel_info_avail(struct device *dev,
 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
 				 int *integer, int *fract, bool scale_db)
 {
-	int i = 0, f = 0;
-	bool integer_part = true, negative = false;
+	s64 integer64, fract64;
+	int ret;
 
-	if (fract_mult == 0) {
-		*fract = 0;
+	ret = __iio_str_to_fixpoint64(str, fract_mult, &integer64, &fract64,
+				      scale_db);
+	if (ret)
+		return ret;
 
-		return kstrtoint(str, 0, integer);
-	}
+	if (integer64 < INT_MIN || integer64 > UINT_MAX ||
+	    fract64 < INT_MIN || fract64 > UINT_MAX)
+		return -ERANGE;
 
-	if (str[0] == '-') {
-		negative = true;
-		str++;
-	} else if (str[0] == '+') {
-		str++;
-	}
-
-	while (*str) {
-		if ('0' <= *str && *str <= '9') {
-			if (integer_part) {
-				i = i * 10 + *str - '0';
-			} else {
-				f += fract_mult * (*str - '0');
-				fract_mult /= 10;
-			}
-		} else if (*str == '\n') {
-			if (*(str + 1) == '\0')
-				break;
-			return -EINVAL;
-		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
-			/* Ignore the dB suffix */
-			str += sizeof(" dB") - 1;
-			continue;
-		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
-			/* Ignore the dB suffix */
-			str += sizeof("dB") - 1;
-			continue;
-		} else if (*str == '.' && integer_part) {
-			integer_part = false;
-		} else {
-			return -EINVAL;
-		}
-		str++;
-	}
-
-	if (negative) {
-		if (i)
-			i = -i;
-		else
-			f = -f;
-	}
-
-	*integer = i;
-	*fract = f;
+	*integer = integer64;
+	*fract = fract64;
 
 	return 0;
 }
 
+/**
+ * iio_str_to_fixpoint64() - Parse a fixed-point number from a string
+ * @str: The string to parse
+ * @fract_mult: Multiplier for the first decimal place, should be a power of 10
+ * @integer: The integer part of the number
+ * @fract: The fractional part of the number
+ *
+ * This variant uses 64-bit integers for both integer and fractional parts.
+ *
+ * Returns:
+ * 0 on success, or a negative error code if the string could not be parsed.
+ */
+int iio_str_to_fixpoint64(const char *str, u64 fract_mult, s64 *integer,
+			  s64 *fract)
+{
+	return __iio_str_to_fixpoint64(str, fract_mult, integer, fract, false);
+}
+EXPORT_SYMBOL_GPL(iio_str_to_fixpoint64);
+
 /**
  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
  * @str: The string to parse
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index a9ecff191bd9..cb30d153465a 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -1055,6 +1055,8 @@ int iio_active_scan_mask_index(struct iio_dev *indio_dev);
 
 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals);
 
+int iio_str_to_fixpoint64(const char *str, u64 fract_mult, s64 *integer,
+			  s64 *fract);
 int iio_str_to_fixpoint(const char *str, int fract_mult, int *integer,
 	int *fract);
 

-- 
2.43.0

[PATCH v9 4/9] iio: test: add kunit test for fixed-point parsing

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

Add kunit test cases that aims to verify expected behavior for
iio_str_to_fixpoint() and iio_str_to_fixpoint64().
To run the test, create a .kunitconfig file with:

CONFIG_KUNIT=y
CONFIG_IIO=y
CONFIG_IIO_FIXPOINT_PARSE_KUNIT_TEST=y

and run the command:
./tools/testing/kunit/kunit.py run --kunitconfig=.kunitconfig

Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 MAINTAINERS                                |   6 +
 drivers/iio/test/Kconfig                   |  12 +
 drivers/iio/test/Makefile                  |   1 +
 drivers/iio/test/iio-test-fixpoint-parse.c | 470 +++++++++++++++++++++++++++++
 4 files changed, 489 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index e3568f08ea55..3acfee7a66cd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12455,6 +12455,12 @@ F:	include/dt-bindings/iio/
 F:	include/linux/iio/
 F:	tools/iio/
 
+IIO FIXED POINT PARSE TEST
+M:	Rodrigo Alencar <rodrigo.alencar@analog.com>
+L:	linux-iio@vger.kernel.org
+S:	Maintained
+F:	drivers/iio/test/iio-test-fixpoint-parse.c
+
 IIO UNIT CONVERTER
 M:	Peter Rosin <peda@axentia.se>
 L:	linux-iio@vger.kernel.org
diff --git a/drivers/iio/test/Kconfig b/drivers/iio/test/Kconfig
index 4fc17dd0dcd7..c60dff504bc2 100644
--- a/drivers/iio/test/Kconfig
+++ b/drivers/iio/test/Kconfig
@@ -29,6 +29,18 @@ config IIO_RESCALE_KUNIT_TEST
 
 	  If unsure, say N.
 
+config IIO_FIXPOINT_PARSE_KUNIT_TEST
+	tristate "Test IIO fixpoint parsing functions" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  build unit tests for the IIO fixpoint parsing functions.
+
+	  For more information on KUnit and unit tests in general, please refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+	  If unsure, say N.
+
 config IIO_FORMAT_KUNIT_TEST
 	tristate "Test IIO formatting functions" if !KUNIT_ALL_TESTS
 	depends on KUNIT
diff --git a/drivers/iio/test/Makefile b/drivers/iio/test/Makefile
index 0c846bc21acd..0c31aaeed755 100644
--- a/drivers/iio/test/Makefile
+++ b/drivers/iio/test/Makefile
@@ -5,6 +5,7 @@
 
 # Keep in alphabetical order
 obj-$(CONFIG_IIO_RESCALE_KUNIT_TEST) += iio-test-rescale.o
+obj-$(CONFIG_IIO_FIXPOINT_PARSE_KUNIT_TEST) += iio-test-fixpoint-parse.o
 obj-$(CONFIG_IIO_FORMAT_KUNIT_TEST) += iio-test-format.o
 obj-$(CONFIG_IIO_GTS_KUNIT_TEST) += iio-test-gts.o
 obj-$(CONFIG_IIO_MULTIPLY_KUNIT_TEST) += iio-test-multiply.o
diff --git a/drivers/iio/test/iio-test-fixpoint-parse.c b/drivers/iio/test/iio-test-fixpoint-parse.c
new file mode 100644
index 000000000000..69715d22d7ec
--- /dev/null
+++ b/drivers/iio/test/iio-test-fixpoint-parse.c
@@ -0,0 +1,470 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Unit tests for IIO fixpoint parsing functions
+ *
+ * Copyright 2026 Analog Devices Inc.
+ */
+
+#include <kunit/test.h>
+#include <linux/errno.h>
+#include <linux/iio/iio.h>
+#include <linux/limits.h>
+#include <linux/math.h>
+#include <linux/types.h>
+
+#define PRECISION(x)	(int_pow(10, (x) - 1))
+
+/* Test iio_str_to_fixpoint64() with valid positive integers */
+static void iio_test_str_to_fixpoint64_positive_integers(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* Simple positive integer */
+	ret = iio_str_to_fixpoint64("42", 0, &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 42);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+
+	/* Positive integer with leading + */
+	ret = iio_str_to_fixpoint64("+10", 0, &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 10);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+
+	/* Large positive integer */
+	ret = iio_str_to_fixpoint64("123456789", 0, &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 123456789);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+}
+
+/* Test iio_str_to_fixpoint64() with valid negative integers */
+static void iio_test_str_to_fixpoint64_negative_integers(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* Simple negative integer */
+	ret = iio_str_to_fixpoint64("-23", 0, &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, -23);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+
+	/* Large negative integer */
+	ret = iio_str_to_fixpoint64("-987654321", 0, &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, -987654321);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+}
+
+/* Test iio_str_to_fixpoint64() with zero */
+static void iio_test_str_to_fixpoint64_zero(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* Zero */
+	ret = iio_str_to_fixpoint64("0", 0, &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+
+	/* Zero with decimal */
+	ret = iio_str_to_fixpoint64("0.0", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+
+	/* leading zeros */
+	ret = iio_str_to_fixpoint64("00000000000000000000042", 0, &integer,
+				    &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 42);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+}
+
+/* Test iio_str_to_fixpoint64() with valid decimal numbers */
+static void iio_test_str_to_fixpoint64_positive_decimals(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* Positive decimal */
+	ret = iio_str_to_fixpoint64("3.14", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 3);
+	KUNIT_EXPECT_EQ(test, fract, 140000);
+
+	/* Decimal less than 1 */
+	ret = iio_str_to_fixpoint64("0.5", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, 500000);
+
+	/* Decimal with trailing zeros */
+	ret = iio_str_to_fixpoint64("+123.000", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 123);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+
+	/* High precision decimal */
+	ret = iio_str_to_fixpoint64("1.123456789", PRECISION(9), &integer,
+				    &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 1);
+	KUNIT_EXPECT_EQ(test, fract, 123456789);
+
+	/* Small decimal */
+	ret = iio_str_to_fixpoint64("0.000000001", PRECISION(9), &integer,
+				    &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, 1);
+}
+
+/* Test iio_str_to_fixpoint64() with negative decimals */
+static void iio_test_str_to_fixpoint64_negative_decimals(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* Negative decimal */
+	ret = iio_str_to_fixpoint64("-2.71", PRECISION(5), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, -2);
+	KUNIT_EXPECT_EQ(test, fract, 71000);
+
+	/* Negative decimal less than -1 */
+	ret = iio_str_to_fixpoint64("-0.5", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, -500000);
+
+	/* Negative with high precision */
+	ret = iio_str_to_fixpoint64("-0.000000001", PRECISION(9), &integer,
+				    &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, -1);
+}
+
+/* Test iio_str_to_fixpoint64() with precision edge cases */
+static void iio_test_str_to_fixpoint64_precision_edge_cases(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* More digits than precision - should truncate */
+	ret = iio_str_to_fixpoint64("1.23456", PRECISION(3), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 1);
+	KUNIT_EXPECT_EQ(test, fract, 234);
+
+	/* Fewer digits than precision - should pad with zeros */
+	ret = iio_str_to_fixpoint64("1.23", PRECISION(7), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 1);
+	KUNIT_EXPECT_EQ(test, fract, 2300000);
+
+	/* Single digit fractional with high precision */
+	ret = iio_str_to_fixpoint64("5.1", PRECISION(9), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 5);
+	KUNIT_EXPECT_EQ(test, fract, 100000000);
+}
+
+/* Test iio_str_to_fixpoint64() with newline characters */
+static void iio_test_str_to_fixpoint64_with_newline(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* Integer with newline */
+	ret = iio_str_to_fixpoint64("-42\n", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, -42);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+
+	/* Decimal with newline */
+	ret = iio_str_to_fixpoint64("3.141\n", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 3);
+	KUNIT_EXPECT_EQ(test, fract, 141000);
+}
+
+/* Test iio_str_to_fixpoint64() with edge cases */
+static void iio_test_str_to_fixpoint64_edge_cases(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* Leading decimal point */
+	ret = iio_str_to_fixpoint64(".5", PRECISION(4), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, 5000);
+
+	/* Leading decimal with sign */
+	ret = iio_str_to_fixpoint64("-.5", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, -500000);
+
+	ret = iio_str_to_fixpoint64("+.5", PRECISION(3), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, 500);
+}
+
+/* Test iio_str_to_fixpoint64() with invalid inputs */
+static void iio_test_str_to_fixpoint64_invalid(struct kunit *test)
+{
+	s64 integer, fract;
+	int ret;
+
+	/* Empty string */
+	ret = iio_str_to_fixpoint64("", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	/* Just a sign */
+	ret = iio_str_to_fixpoint64("-", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	ret = iio_str_to_fixpoint64("+", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	/* Just a decimal point */
+	ret = iio_str_to_fixpoint64(".", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	/* Non-numeric characters */
+	ret = iio_str_to_fixpoint64("abc", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	ret = iio_str_to_fixpoint64("12a", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	ret = iio_str_to_fixpoint64("3.4x", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	ret = iio_str_to_fixpoint64("0xff", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	/* Multiple decimal points */
+	ret = iio_str_to_fixpoint64("12.34.56", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	/* Trailing decimal without digits */
+	ret = iio_str_to_fixpoint64("42.", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	/* Trailing spaces */
+	ret = iio_str_to_fixpoint64("42 ", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+
+	/* Too many digits in fractional part */
+	ret = iio_str_to_fixpoint64("1.123456789012345678901", PRECISION(21),
+				    &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL); /* fails when checking precision */
+}
+
+/* Test iio_str_to_fixpoint() with valid inputs */
+static void iio_test_str_to_fixpoint_valid(struct kunit *test)
+{
+	int integer, fract;
+	int ret;
+
+	/* Test with 6 decimal places */
+	ret = iio_str_to_fixpoint("10.001234", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 10);
+	KUNIT_EXPECT_EQ(test, fract, 1234);
+
+	ret = iio_str_to_fixpoint("-0.5", PRECISION(3), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 0);
+	KUNIT_EXPECT_EQ(test, fract, -500);
+
+	/* Test with 9 decimal places */
+	ret = iio_str_to_fixpoint("5.123456789", PRECISION(9), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 5);
+	KUNIT_EXPECT_EQ(test, fract, 123456789);
+
+	ret = iio_str_to_fixpoint("1.0", PRECISION(9), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 1);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+
+	/* Test with 3 decimal places */
+	ret = iio_str_to_fixpoint("-7.8", PRECISION(3), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, -7);
+	KUNIT_EXPECT_EQ(test, fract, 800);
+
+	/* Truncation with 2 decimal places */
+	ret = iio_str_to_fixpoint("3.1415", PRECISION(2), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 3);
+	KUNIT_EXPECT_EQ(test, fract, 14);
+
+	/* Integer with 6 decimal places */
+	ret = iio_str_to_fixpoint("42", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer, 42);
+	KUNIT_EXPECT_EQ(test, fract, 0);
+}
+
+/* Test both functions with overflow cases */
+static void iio_test_str_to_fixpoint_overflow(struct kunit *test)
+{
+	s64 integer64, fract64;
+	int integer, fract;
+	int ret;
+
+	/* integer overflow - value exceeds U64_MAX */
+	ret = iio_str_to_fixpoint64("18446744073709551616", PRECISION(6),
+				    &integer64, &fract64);
+	KUNIT_EXPECT_EQ(test, ret, -ERANGE);
+
+	/* integer underflow - value less than S64_MIN */
+	ret = iio_str_to_fixpoint64("-9223372036854775809", PRECISION(6),
+				    &integer64, &fract64);
+	KUNIT_EXPECT_EQ(test, ret, -ERANGE);
+
+	/* fractional underflow */
+	ret = iio_str_to_fixpoint64("-0.9223372036854775810", PRECISION(19),
+				    &integer64, &fract64);
+	KUNIT_EXPECT_EQ(test, ret, -ERANGE);
+
+	/* Integer overflow - value exceeds U32_MAX */
+	ret = iio_str_to_fixpoint("4294967296", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -ERANGE);
+
+	/* Integer underflow - value less than INT_MIN */
+	ret = iio_str_to_fixpoint("-2147483649", PRECISION(6), &integer,
+				  &fract);
+	KUNIT_EXPECT_EQ(test, ret, -ERANGE);
+
+	/* fractional overflow */
+	ret = iio_str_to_fixpoint("0.4294967296", PRECISION(10), &integer,
+				  &fract);
+	KUNIT_EXPECT_EQ(test, ret, -ERANGE);
+
+	/* fractional underflow */
+	ret = iio_str_to_fixpoint("-0.2147483649", PRECISION(10), &integer,
+				  &fract);
+	KUNIT_EXPECT_EQ(test, ret, -ERANGE);
+}
+
+/* Test iio_str_to_fixpoint() with invalid inputs */
+static void iio_test_str_to_fixpoint_invalid(struct kunit *test)
+{
+	int integer, fract;
+	int ret;
+
+	/* Empty string */
+	ret = iio_str_to_fixpoint("", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_NE(test, ret, 0);
+
+	/* Non-numeric */
+	ret = iio_str_to_fixpoint("abc", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_NE(test, ret, 0);
+
+	/* Invalid characters */
+	ret = iio_str_to_fixpoint("12.34x", PRECISION(6), &integer, &fract);
+	KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+}
+
+/* Test both functions with boundary values */
+static void iio_test_fixpoint_boundary_values(struct kunit *test)
+{
+	s64 integer64, fract64;
+	int integer32, fract32;
+	int ret;
+
+	/* S32_MAX */
+	ret = iio_str_to_fixpoint("2147483647", PRECISION(6), &integer32,
+				  &fract32);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer32, S32_MAX);
+	KUNIT_EXPECT_EQ(test, fract32, 0);
+
+	/* U32_MAX */
+	ret = iio_str_to_fixpoint("4294967295", PRECISION(6), &integer32,
+				  &fract32);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, (u32)integer32, U32_MAX);
+	KUNIT_EXPECT_EQ(test, fract32, 0);
+
+	/* S32_MIN */
+	ret = iio_str_to_fixpoint("-2147483648", PRECISION(6), &integer32,
+				  &fract32);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer32, S32_MIN);
+	KUNIT_EXPECT_EQ(test, fract32, 0);
+
+	/* S32_MIN with fractional part */
+	ret = iio_str_to_fixpoint("-2147483648.2147483647", PRECISION(10),
+				  &integer32, &fract32);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer32, S32_MIN);
+	KUNIT_EXPECT_EQ(test, fract32, S32_MAX);
+
+	/* S64_MAX */
+	ret = iio_str_to_fixpoint64("9223372036854775807", PRECISION(6),
+				    &integer64, &fract64);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer64, S64_MAX);
+	KUNIT_EXPECT_EQ(test, fract64, 0);
+
+	/* U64_MAX */
+	ret = iio_str_to_fixpoint64("18446744073709551615", PRECISION(6),
+				    &integer64, &fract64);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, (u64)integer64, U64_MAX);
+	KUNIT_EXPECT_EQ(test, fract64, 0);
+
+	/* S64_MIN */
+	ret = iio_str_to_fixpoint64("-9223372036854775808", PRECISION(6),
+				    &integer64, &fract64);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer64, S64_MIN);
+	KUNIT_EXPECT_EQ(test, fract64, 0);
+
+	/* S64_MIN with fractional part */
+	ret = iio_str_to_fixpoint64("-9223372036854775808.9223372036854775807",
+				    PRECISION(19), &integer64, &fract64);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, integer64, S64_MIN);
+	KUNIT_EXPECT_EQ(test, fract64, S64_MAX);
+}
+
+static struct kunit_case iio_fixpoint_parse_test_cases[] = {
+	KUNIT_CASE(iio_test_str_to_fixpoint64_positive_integers),
+	KUNIT_CASE(iio_test_str_to_fixpoint64_negative_integers),
+	KUNIT_CASE(iio_test_str_to_fixpoint64_zero),
+	KUNIT_CASE(iio_test_str_to_fixpoint64_positive_decimals),
+	KUNIT_CASE(iio_test_str_to_fixpoint64_negative_decimals),
+	KUNIT_CASE(iio_test_str_to_fixpoint64_precision_edge_cases),
+	KUNIT_CASE(iio_test_str_to_fixpoint64_with_newline),
+	KUNIT_CASE(iio_test_str_to_fixpoint64_edge_cases),
+	KUNIT_CASE(iio_test_str_to_fixpoint64_invalid),
+	KUNIT_CASE(iio_test_str_to_fixpoint_valid),
+	KUNIT_CASE(iio_test_str_to_fixpoint_overflow),
+	KUNIT_CASE(iio_test_str_to_fixpoint_invalid),
+	KUNIT_CASE(iio_test_fixpoint_boundary_values),
+	{ }
+};
+
+static struct kunit_suite iio_fixpoint_parse_test_suite = {
+	.name = "iio-fixpoint-parse",
+	.test_cases = iio_fixpoint_parse_test_cases,
+};
+
+kunit_test_suite(iio_fixpoint_parse_test_suite);
+
+MODULE_AUTHOR("Rodrigo Alencar <rodrigo.alencar@analog.com>");
+MODULE_AUTHOR("IIO Kunit Test");
+MODULE_DESCRIPTION("Test IIO fixpoint parsing functions");
+MODULE_LICENSE("GPL");

-- 
2.43.0

[PATCH v9 5/9] iio: frequency: adf41513: driver implementation

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

The driver is based on existing PLL drivers in the IIO subsystem and
implements the following key features:

- Integer-N and fractional-N (fixed/variable modulus) synthesis modes
- High-resolution frequency calculations using microhertz (µHz) precision
  to handle sub-Hz resolution across multi-GHz frequency ranges
- IIO debugfs interface for direct register access
- FW property parsing from devicetree including charge pump settings,
  reference path configuration and muxout options
- Power management support with suspend/resume callbacks
- Lock detect GPIO monitoring

The driver uses 64-bit microhertz values throughout PLL calculations to
maintain precision when working with frequencies that exceed 32-bit Hz
representation while requiring fractional Hz resolution.

When merging, ADF41513_HZ_PER_GHZ must be dropped in favor of
HZ_PER_GHZ defined in linux/units.h.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 MAINTAINERS                      |    1 +
 drivers/iio/frequency/Kconfig    |   10 +
 drivers/iio/frequency/Makefile   |    1 +
 drivers/iio/frequency/adf41513.c | 1111 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 1123 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 3acfee7a66cd..fb723e40f1a9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1660,6 +1660,7 @@ L:	linux-iio@vger.kernel.org
 S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/frequency/adi,adf41513.yaml
+F:	drivers/iio/frequency/adf41513.c
 
 ANALOG DEVICES INC ADF4377 DRIVER
 M:	Antoniu Miclaus <antoniu.miclaus@analog.com>
diff --git a/drivers/iio/frequency/Kconfig b/drivers/iio/frequency/Kconfig
index 583cbdf4e8cd..90c6304c4bcd 100644
--- a/drivers/iio/frequency/Kconfig
+++ b/drivers/iio/frequency/Kconfig
@@ -29,6 +29,16 @@ endmenu
 
 menu "Phase-Locked Loop (PLL) frequency synthesizers"
 
+config ADF41513
+	tristate "Analog Devices ADF41513 PLL Frequency Synthesizer"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices ADF41513
+	  26.5 GHz Integer-N/Fractional-N PLL Frequency Synthesizer.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called adf41513.
+
 config ADF4350
 	tristate "Analog Devices ADF4350/ADF4351 Wideband Synthesizers"
 	depends on SPI
diff --git a/drivers/iio/frequency/Makefile b/drivers/iio/frequency/Makefile
index 70d0e0b70e80..53b4d01414d8 100644
--- a/drivers/iio/frequency/Makefile
+++ b/drivers/iio/frequency/Makefile
@@ -5,6 +5,7 @@
 
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_AD9523) += ad9523.o
+obj-$(CONFIG_ADF41513) += adf41513.o
 obj-$(CONFIG_ADF4350) += adf4350.o
 obj-$(CONFIG_ADF4371) += adf4371.o
 obj-$(CONFIG_ADF4377) += adf4377.o
diff --git a/drivers/iio/frequency/adf41513.c b/drivers/iio/frequency/adf41513.c
new file mode 100644
index 000000000000..5a0682667d1f
--- /dev/null
+++ b/drivers/iio/frequency/adf41513.c
@@ -0,0 +1,1111 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ADF41513 SPI PLL Frequency Synthesizer driver
+ *
+ * Copyright 2026 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/log2.h>
+#include <linux/math64.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+/* Registers */
+#define ADF41513_REG0		0
+#define ADF41513_REG1		1
+#define ADF41513_REG2		2
+#define ADF41513_REG3		3
+#define ADF41513_REG4		4
+#define ADF41513_REG5		5
+#define ADF41513_REG6		6
+#define ADF41513_REG7		7
+#define ADF41513_REG8		8
+#define ADF41513_REG9		9
+#define ADF41513_REG10		10
+#define ADF41513_REG11		11
+#define ADF41513_REG12		12
+#define ADF41513_REG13		13
+#define ADF41513_REG_NUM	14
+
+#define ADF41513_SYNC_REG0	BIT(ADF41513_REG0)
+#define ADF41513_SYNC_REG1	BIT(ADF41513_REG1)
+#define ADF41513_SYNC_REG2	BIT(ADF41513_REG2)
+#define ADF41513_SYNC_REG3	BIT(ADF41513_REG3)
+#define ADF41513_SYNC_REG4	BIT(ADF41513_REG4)
+#define ADF41513_SYNC_REG5	BIT(ADF41513_REG5)
+#define ADF41513_SYNC_REG6	BIT(ADF41513_REG6)
+#define ADF41513_SYNC_REG7	BIT(ADF41513_REG7)
+#define ADF41513_SYNC_REG9	BIT(ADF41513_REG9)
+#define ADF41513_SYNC_REG11	BIT(ADF41513_REG11)
+#define ADF41513_SYNC_REG12	BIT(ADF41513_REG12)
+#define ADF41513_SYNC_REG13	BIT(ADF41513_REG13)
+#define ADF41513_SYNC_DIFF	0
+#define ADF41513_SYNC_ALL	GENMASK(ADF41513_REG13, ADF41513_REG0)
+
+/* REG0 Bit Definitions */
+#define ADF41513_REG0_CTRL_BITS_MSK		GENMASK(3, 0)
+#define ADF41513_REG0_INT_MSK			GENMASK(19, 4)
+#define ADF41513_REG0_VAR_MOD_MSK		BIT(28)
+
+/* REG1 Bit Definitions */
+#define ADF41513_REG1_FRAC1_MSK			GENMASK(28, 4)
+#define ADF41513_REG1_DITHER2_MSK		BIT(31)
+
+/* REG2 Bit Definitions */
+#define ADF41513_REG2_PHASE_VAL_MSK		GENMASK(15, 4)
+#define ADF41513_REG2_PHASE_ADJ_MSK		BIT(31)
+
+/* REG3 Bit Definitions */
+#define ADF41513_REG3_FRAC2_MSK			GENMASK(27, 4)
+
+/* REG4 Bit Definitions */
+#define ADF41513_REG4_MOD2_MSK			GENMASK(27, 4)
+
+/* REG5 Bit Definitions */
+#define ADF41513_REG5_CLK1_DIV_MSK		GENMASK(15, 4)
+#define ADF41513_REG5_R_CNT_MSK			GENMASK(20, 16)
+#define ADF41513_REG5_REF_DOUBLER_MSK		BIT(21)
+#define ADF41513_REG5_RDIV2_MSK			BIT(22)
+#define ADF41513_REG5_PRESCALER_MSK		BIT(23)
+#define ADF41513_REG5_LSB_P1_MSK		BIT(24)
+#define ADF41513_REG5_CP_CURRENT_MSK		GENMASK(28, 25)
+#define ADF41513_REG5_DLD_MODES_MSK		GENMASK(31, 30)
+
+/* REG6 Bit Definitions */
+#define ADF41513_REG6_COUNTER_RESET_MSK		BIT(4)
+#define ADF41513_REG6_CP_TRISTATE_MSK		BIT(5)
+#define ADF41513_REG6_POWER_DOWN_MSK		BIT(6)
+#define ADF41513_REG6_PD_POLARITY_MSK		BIT(7)
+#define ADF41513_REG6_LDP_MSK			GENMASK(9, 8)
+#define ADF41513_REG6_CP_TRISTATE_PD_ON_MSK	BIT(16)
+#define ADF41513_REG6_SD_RESET_MSK		BIT(17)
+#define ADF41513_REG6_LOL_ENABLE_MSK		BIT(18)
+#define ADF41513_REG6_ABP_MSK			BIT(19)
+#define ADF41513_REG6_INT_MODE_MSK		BIT(20)
+#define ADF41513_REG6_BLEED_ENABLE_MSK		BIT(22)
+#define ADF41513_REG6_BLEED_POLARITY_MSK	BIT(23)
+#define ADF41513_REG6_BLEED_CURRENT_MSK		GENMASK(31, 24)
+
+/* REG7 Bit Definitions */
+#define ADF41513_REG7_CLK2_DIV_MSK		GENMASK(17, 6)
+#define ADF41513_REG7_CLK_DIV_MODE_MSK		GENMASK(19, 18)
+#define ADF41513_REG7_PS_BIAS_MSK		GENMASK(21, 20)
+#define ADF41513_REG7_N_DELAY_MSK		GENMASK(23, 22)
+#define ADF41513_REG7_LD_CLK_SEL_MSK		BIT(26)
+#define ADF41513_REG7_LD_COUNT_MSK		GENMASK(29, 27)
+
+/* REG9 Bit Definitions */
+#define ADF41513_REG9_LD_BIAS_MSK		GENMASK(31, 30)
+
+/* REG11 Bit Definitions */
+#define ADF41513_REG11_POWER_DOWN_SEL_MSK	BIT(31)
+
+/* REG12 Bit Definitions */
+#define ADF41513_REG12_READBACK_SEL_MSK		GENMASK(19, 14)
+#define ADF41513_REG12_LE_SELECT_MSK		BIT(20)
+#define ADF41513_REG12_MASTER_RESET_MSK		BIT(22)
+#define ADF41513_REG12_LOGIC_LEVEL_MSK		BIT(27)
+#define ADF41513_REG12_MUXOUT_MSK		GENMASK(31, 28)
+
+/* MUXOUT Selection */
+#define ADF41513_MUXOUT_TRISTATE		0x0
+#define ADF41513_MUXOUT_DVDD			0x1
+#define ADF41513_MUXOUT_DGND			0x2
+#define ADF41513_MUXOUT_R_DIV			0x3
+#define ADF41513_MUXOUT_N_DIV			0x4
+#define ADF41513_MUXOUT_DIG_LD			0x6
+#define ADF41513_MUXOUT_SDO			0x7
+#define ADF41513_MUXOUT_READBACK		0x8
+#define ADF41513_MUXOUT_CLK1_DIV		0xA
+#define ADF41513_MUXOUT_R_DIV2			0xD
+#define ADF41513_MUXOUT_N_DIV2			0xE
+
+/* DLD Mode Selection */
+#define ADF41513_DLD_TRISTATE			0x0
+#define ADF41513_DLD_DIG_LD			0x1
+#define ADF41513_DLD_LOW			0x2
+#define ADF41513_DLD_HIGH			0x3
+
+/* Prescaler Selection */
+#define ADF41513_PRESCALER_4_5			0
+#define ADF41513_PRESCALER_8_9			1
+#define ADF41513_PRESCALER_AUTO			2
+
+/* Specifications */
+#define ADF41513_HZ_PER_GHZ			1000000000UL
+#define ADF41510_MAX_RF_FREQ_HZ			(10ULL * ADF41513_HZ_PER_GHZ)
+#define ADF41513_MIN_RF_FREQ_HZ			(1ULL * ADF41513_HZ_PER_GHZ)
+#define ADF41513_MAX_RF_FREQ_HZ			(26500ULL * HZ_PER_MHZ)
+
+#define ADF41513_MIN_REF_FREQ_HZ		(10 * HZ_PER_MHZ)
+#define ADF41513_MAX_REF_FREQ_HZ		(800 * HZ_PER_MHZ)
+#define ADF41513_MAX_REF_FREQ_DOUBLER_HZ	(225 * HZ_PER_MHZ)
+
+#define ADF41513_MAX_PFD_FREQ_INT_N_UHZ		(250ULL * MEGA * MICROHZ_PER_HZ)
+#define ADF41513_MAX_PFD_FREQ_FRAC_N_UHZ	(125ULL * MEGA * MICROHZ_PER_HZ)
+#define ADF41513_MAX_FREQ_RESOLUTION_UHZ	(100ULL * KILO * MICROHZ_PER_HZ)
+
+#define ADF41513_MIN_INT_4_5			20
+#define ADF41513_MAX_INT_4_5			511
+#define ADF41513_MIN_INT_8_9			64
+#define ADF41513_MAX_INT_8_9			1023
+
+#define ADF41513_MIN_INT_FRAC_4_5		23
+#define ADF41513_MIN_INT_FRAC_8_9		75
+
+#define ADF41513_MIN_R_CNT			1
+#define ADF41513_MAX_R_CNT			32
+
+#define ADF41513_MIN_R_SET			1800
+#define ADF41513_DEFAULT_R_SET			2700
+#define ADF41513_MAX_R_SET			10000
+
+#define ADF41513_MIN_CP_VOLTAGE_mV		810
+#define ADF41513_DEFAULT_CP_VOLTAGE_mV		6480
+#define ADF41513_MAX_CP_VOLTAGE_mV		12960
+
+#define ADF41513_LD_COUNT_FAST_MIN		2
+#define ADF41513_LD_COUNT_FAST_LIMIT		64
+#define ADF41513_LD_COUNT_MIN			64
+#define ADF41513_LD_COUNT_MAX			8192
+
+#define ADF41513_FIXED_MODULUS			BIT(25)
+#define ADF41513_MAX_MOD2			(BIT(24) - 1)
+#define ADF41513_MAX_PHASE_VAL			(BIT(12) - 1)
+#define ADF41513_MAX_CLK_DIVIDER		(BIT(12) - 1)
+
+#define ADF41513_HZ_DECIMAL_PRECISION		6
+#define ADF41513_PS_BIAS_INIT			0x2
+#define ADF41513_MAX_PHASE_MICRORAD		((2 * 314159265UL) / 100)
+
+enum {
+	ADF41513_FREQ,
+	ADF41513_POWER_DOWN,
+	ADF41513_FREQ_RESOLUTION,
+};
+
+enum adf41513_pll_mode {
+	ADF41513_MODE_INVALID,
+	ADF41513_MODE_INTEGER_N,
+	ADF41513_MODE_FIXED_MODULUS,
+	ADF41513_MODE_VARIABLE_MODULUS,
+};
+
+struct adf41513_chip_info {
+	const char *name;
+	u64 max_rf_freq_hz;
+	bool has_prescaler_8_9;
+};
+
+struct adf41513_data {
+	u64 power_up_frequency_hz;
+	u64 freq_resolution_uhz;
+	u32 charge_pump_voltage_mv;
+	u32 lock_detect_count;
+
+	u8 ref_div_factor;
+	bool ref_doubler_en;
+	bool ref_div2_en;
+	bool phase_detector_polarity;
+
+	bool logic_lvl_1v8_en;
+};
+
+struct adf41513_pll_settings {
+	enum adf41513_pll_mode mode;
+
+	/* reference path parameters */
+	u8 r_counter;
+	u8 ref_doubler;
+	u8 ref_div2;
+	u8 prescaler;
+
+	/* frequency parameters */
+	u64 target_frequency_uhz;
+	u64 actual_frequency_uhz;
+	u64 pfd_frequency_uhz;
+
+	/* pll parameters */
+	u32 frac1;
+	u32 frac2;
+	u32 mod2;
+	u16 int_value;
+};
+
+struct adf41513_state {
+	const struct adf41513_chip_info *chip_info;
+	struct spi_device *spi;
+	struct gpio_desc *lock_detect;
+	struct gpio_desc *chip_enable;
+	struct clk *ref_clk;
+	u32 ref_freq_hz;
+
+	/*
+	 * Lock for accessing device registers. Some operations require
+	 * multiple consecutive R/W operations, during which the device
+	 * shouldn't be interrupted. The buffers are also shared across
+	 * all operations so need to be protected on stand alone reads and
+	 * writes.
+	 */
+	struct mutex lock;
+
+	/* Cached register values */
+	u32 regs[ADF41513_REG_NUM];
+	u32 regs_hw[ADF41513_REG_NUM];
+
+	struct adf41513_data data;
+	struct adf41513_pll_settings settings;
+};
+
+static const char * const adf41513_power_supplies[] = {
+	"avdd1", "avdd2", "avdd3", "avdd4", "avdd5", "vp",
+};
+
+static int adf41513_sync_config(struct adf41513_state *st, u16 sync_mask)
+{
+	__be32 d32;
+	int ret, i;
+
+	/* write registers in reverse order (R13 to R0)*/
+	for (i = ADF41513_REG13; i >= ADF41513_REG0; i--) {
+		if (st->regs_hw[i] == st->regs[i] && !(sync_mask & BIT(i)))
+			continue;
+
+		d32 = cpu_to_be32(st->regs[i] | i);
+		ret = spi_write_then_read(st->spi, &d32, sizeof(d32), NULL, 0);
+		if (ret < 0)
+			return ret;
+		st->regs_hw[i] = st->regs[i];
+		dev_dbg(&st->spi->dev, "REG%d <= 0x%08X\n", i, st->regs[i] | i);
+	}
+
+	return 0;
+}
+
+static u64 adf41513_pll_get_rate(struct adf41513_state *st)
+{
+	struct adf41513_pll_settings *cfg = &st->settings;
+
+	if (cfg->mode != ADF41513_MODE_INVALID)
+		return cfg->actual_frequency_uhz;
+
+	/* get pll settings from regs_hw */
+	cfg->int_value = FIELD_GET(ADF41513_REG0_INT_MSK, st->regs_hw[ADF41513_REG0]);
+	cfg->frac1 = FIELD_GET(ADF41513_REG1_FRAC1_MSK, st->regs_hw[ADF41513_REG1]);
+	cfg->frac2 = FIELD_GET(ADF41513_REG3_FRAC2_MSK, st->regs_hw[ADF41513_REG3]);
+	cfg->mod2 = FIELD_GET(ADF41513_REG4_MOD2_MSK, st->regs_hw[ADF41513_REG4]);
+	cfg->r_counter = FIELD_GET(ADF41513_REG5_R_CNT_MSK, st->regs_hw[ADF41513_REG5]);
+	cfg->ref_doubler = FIELD_GET(ADF41513_REG5_REF_DOUBLER_MSK, st->regs_hw[ADF41513_REG5]);
+	cfg->ref_div2 = FIELD_GET(ADF41513_REG5_RDIV2_MSK, st->regs_hw[ADF41513_REG5]);
+	cfg->prescaler = FIELD_GET(ADF41513_REG5_PRESCALER_MSK, st->regs_hw[ADF41513_REG5]);
+
+	/* calculate pfd frequency */
+	cfg->pfd_frequency_uhz = (u64)st->ref_freq_hz * MICRO;
+	if (cfg->ref_doubler)
+		cfg->pfd_frequency_uhz <<= 1;
+	if (cfg->ref_div2)
+		cfg->pfd_frequency_uhz >>= 1;
+	cfg->pfd_frequency_uhz = div_u64(cfg->pfd_frequency_uhz, cfg->r_counter);
+	cfg->actual_frequency_uhz = (u64)cfg->int_value * cfg->pfd_frequency_uhz;
+
+	/* check if int mode is selected */
+	if (FIELD_GET(ADF41513_REG6_INT_MODE_MSK, st->regs_hw[ADF41513_REG6])) {
+		cfg->mode = ADF41513_MODE_INTEGER_N;
+	} else {
+		cfg->actual_frequency_uhz += mul_u64_u32_div(cfg->pfd_frequency_uhz,
+							     cfg->frac1,
+							     ADF41513_FIXED_MODULUS);
+
+		/* check if variable modulus is selected */
+		if (FIELD_GET(ADF41513_REG0_VAR_MOD_MSK, st->regs_hw[ADF41513_REG0])) {
+			cfg->actual_frequency_uhz +=
+				mul_u64_u64_div_u64(cfg->frac2,
+						    cfg->pfd_frequency_uhz,
+						    (u64)cfg->mod2 * ADF41513_FIXED_MODULUS);
+
+			cfg->mode = ADF41513_MODE_VARIABLE_MODULUS;
+		} else {
+			/* LSB_P1 offset */
+			if (!FIELD_GET(ADF41513_REG5_LSB_P1_MSK, st->regs_hw[ADF41513_REG5]))
+				cfg->actual_frequency_uhz +=
+					div_u64(cfg->pfd_frequency_uhz,
+						2 * ADF41513_FIXED_MODULUS);
+			cfg->mode = ADF41513_MODE_FIXED_MODULUS;
+		}
+	}
+
+	cfg->target_frequency_uhz = cfg->actual_frequency_uhz;
+
+	return cfg->actual_frequency_uhz;
+}
+
+static int adf41513_calc_pfd_frequency(struct adf41513_state *st,
+				       struct adf41513_pll_settings *result,
+				       u64 fpfd_limit_uhz)
+{
+	result->ref_div2 = st->data.ref_div2_en;
+	result->ref_doubler = st->data.ref_doubler_en;
+
+	if (st->data.ref_doubler_en &&
+	    st->ref_freq_hz > ADF41513_MAX_REF_FREQ_DOUBLER_HZ) {
+		result->ref_doubler = 0;
+		dev_warn(&st->spi->dev, "Disabling ref doubler due to high reference frequency\n");
+	}
+
+	result->r_counter = st->data.ref_div_factor - 1;
+	do {
+		result->r_counter++;
+		/* f_PFD = REF_IN × ((1 + D)/(R × (1 + T))) */
+		result->pfd_frequency_uhz = (u64)st->ref_freq_hz * MICRO;
+		if (result->ref_doubler)
+			result->pfd_frequency_uhz <<= 1;
+		if (result->ref_div2)
+			result->pfd_frequency_uhz >>= 1;
+		result->pfd_frequency_uhz = div_u64(result->pfd_frequency_uhz,
+						    result->r_counter);
+	} while (result->pfd_frequency_uhz > fpfd_limit_uhz);
+
+	if (result->r_counter > ADF41513_MAX_R_CNT) {
+		dev_err(&st->spi->dev, "Cannot optimize PFD frequency\n");
+		return -ERANGE;
+	}
+
+	return 0;
+}
+
+static int adf41513_calc_integer_n(struct adf41513_state *st,
+				   struct adf41513_pll_settings *result)
+{
+	u16 max_int = st->chip_info->has_prescaler_8_9 ?
+		      ADF41513_MAX_INT_8_9 : ADF41513_MAX_INT_4_5;
+	u64 freq_error_uhz;
+	u16 int_value = div64_u64_rem(result->target_frequency_uhz, result->pfd_frequency_uhz,
+				      &freq_error_uhz);
+
+	/* check if freq error is within a tolerance of 1/2 resolution */
+	if (freq_error_uhz > (result->pfd_frequency_uhz >> 1) && int_value < max_int) {
+		int_value++;
+		freq_error_uhz = result->pfd_frequency_uhz - freq_error_uhz;
+	}
+
+	if (freq_error_uhz > st->data.freq_resolution_uhz)
+		return -ERANGE;
+
+	/* set prescaler */
+	if (st->chip_info->has_prescaler_8_9 && int_value >= ADF41513_MIN_INT_8_9 &&
+	    int_value <= ADF41513_MAX_INT_8_9)
+		result->prescaler = 1;
+	else if (int_value >= ADF41513_MIN_INT_4_5 && int_value <= ADF41513_MAX_INT_4_5)
+		result->prescaler = 0;
+	else
+		return -ERANGE;
+
+	result->actual_frequency_uhz = (u64)int_value * result->pfd_frequency_uhz;
+	result->mode = ADF41513_MODE_INTEGER_N;
+	result->int_value = int_value;
+	result->frac1 = 0;
+	result->frac2 = 0;
+	result->mod2 = 0;
+
+	return 0;
+}
+
+static int adf41513_calc_fixed_mod(struct adf41513_state *st,
+				   struct adf41513_pll_settings *result)
+{
+	u64 freq_error_uhz;
+	u64 resolution_uhz = div_u64(result->pfd_frequency_uhz, ADF41513_FIXED_MODULUS);
+	u64 target_frequency_uhz = result->target_frequency_uhz;
+	u32 frac1;
+	u16 int_value;
+	bool lsb_p1_offset = !FIELD_GET(ADF41513_REG5_LSB_P1_MSK, st->regs_hw[ADF41513_REG5]);
+
+	/* LSB_P1 adds a frequency offset of f_pfd/2^26 */
+	if (lsb_p1_offset)
+		target_frequency_uhz -= resolution_uhz >> 1;
+
+	int_value = div64_u64_rem(target_frequency_uhz, result->pfd_frequency_uhz,
+				  &freq_error_uhz);
+
+	if (st->chip_info->has_prescaler_8_9 && int_value >= ADF41513_MIN_INT_FRAC_8_9 &&
+	    int_value <= ADF41513_MAX_INT_8_9)
+		result->prescaler = 1;
+	else if (int_value >= ADF41513_MIN_INT_FRAC_4_5 && int_value <= ADF41513_MAX_INT_4_5)
+		result->prescaler = 0;
+	else
+		return -ERANGE;
+
+	/* compute frac1 and fixed modulus error */
+	frac1 = mul_u64_u64_div_u64(freq_error_uhz, ADF41513_FIXED_MODULUS,
+				    result->pfd_frequency_uhz);
+	freq_error_uhz -= mul_u64_u32_div(result->pfd_frequency_uhz, frac1,
+					  ADF41513_FIXED_MODULUS);
+
+	/* check if freq error is within a tolerance of 1/2 resolution */
+	if (freq_error_uhz > (resolution_uhz >> 1) && frac1 < (ADF41513_FIXED_MODULUS - 1)) {
+		frac1++;
+		freq_error_uhz = resolution_uhz - freq_error_uhz;
+	}
+
+	if (freq_error_uhz > st->data.freq_resolution_uhz)
+		return -ERANGE;
+
+	/* integer part */
+	result->actual_frequency_uhz = (u64)int_value * result->pfd_frequency_uhz;
+	/* fractional part */
+	if (lsb_p1_offset)
+		result->actual_frequency_uhz +=	(resolution_uhz >> 1);
+	result->actual_frequency_uhz += mul_u64_u32_div(result->pfd_frequency_uhz, frac1,
+							ADF41513_FIXED_MODULUS);
+	result->mode = ADF41513_MODE_FIXED_MODULUS;
+	result->int_value = int_value;
+	result->frac1 = frac1;
+	result->frac2 = 0;
+	result->mod2 = 0;
+
+	return 0;
+}
+
+static int adf41513_calc_variable_mod(struct adf41513_state *st,
+				      struct adf41513_pll_settings *result)
+{
+	u64 freq_error_uhz, mod2;
+	u32 frac1, frac2;
+	u16 int_value = div64_u64_rem(result->target_frequency_uhz,
+				      result->pfd_frequency_uhz,
+				      &freq_error_uhz);
+
+	if (st->chip_info->has_prescaler_8_9 && int_value >= ADF41513_MIN_INT_FRAC_8_9 &&
+	    int_value <= ADF41513_MAX_INT_8_9)
+		result->prescaler = 1;
+	else if (int_value >= ADF41513_MIN_INT_FRAC_4_5 && int_value <= ADF41513_MAX_INT_4_5)
+		result->prescaler = 0;
+	else
+		return -ERANGE;
+
+	/* calculate required mod2 based on target resolution / 2 */
+	mod2 = DIV64_U64_ROUND_CLOSEST(result->pfd_frequency_uhz << 1,
+				       st->data.freq_resolution_uhz * ADF41513_FIXED_MODULUS);
+	/* ensure mod2 is at least 2 for meaningful operation */
+	mod2 = clamp(mod2, 2, ADF41513_MAX_MOD2);
+
+	/* calculate frac1 and frac2 */
+	frac1 = mul_u64_u64_div_u64(freq_error_uhz, ADF41513_FIXED_MODULUS,
+				    result->pfd_frequency_uhz);
+	freq_error_uhz -= mul_u64_u32_div(result->pfd_frequency_uhz, frac1,
+					  ADF41513_FIXED_MODULUS);
+	frac2 = mul_u64_u64_div_u64(freq_error_uhz, mod2 * ADF41513_FIXED_MODULUS,
+				    result->pfd_frequency_uhz);
+
+	/* integer part */
+	result->actual_frequency_uhz = (u64)int_value * result->pfd_frequency_uhz;
+	/* fractional part */
+	result->actual_frequency_uhz += mul_u64_u64_div_u64(mod2 * frac1 + frac2,
+							    result->pfd_frequency_uhz,
+							    mod2 * ADF41513_FIXED_MODULUS);
+	result->mode = ADF41513_MODE_VARIABLE_MODULUS;
+	result->int_value = int_value;
+	result->frac1 = frac1;
+	result->frac2 = frac2;
+	result->mod2 = mod2;
+
+	return 0;
+}
+
+static int adf41513_calc_pll_settings(struct adf41513_state *st,
+				      struct adf41513_pll_settings *result,
+				      u64 rf_out_uhz)
+{
+	u64 max_rf_freq_uhz = st->chip_info->max_rf_freq_hz * MICRO;
+	u64 min_rf_freq_uhz = ADF41513_MIN_RF_FREQ_HZ * MICRO;
+	u64 pfd_freq_limit_uhz;
+	int ret;
+
+	if (rf_out_uhz < min_rf_freq_uhz || rf_out_uhz > max_rf_freq_uhz) {
+		dev_err(&st->spi->dev, "RF frequency %llu uHz out of range [%llu, %llu] uHz\n",
+			rf_out_uhz, min_rf_freq_uhz, max_rf_freq_uhz);
+		return -EINVAL;
+	}
+
+	result->target_frequency_uhz = rf_out_uhz;
+
+	/* try integer-N first (best phase noise performance) */
+	pfd_freq_limit_uhz = min(div_u64(rf_out_uhz, ADF41513_MIN_INT_4_5),
+				 ADF41513_MAX_PFD_FREQ_INT_N_UHZ);
+	ret = adf41513_calc_pfd_frequency(st, result, pfd_freq_limit_uhz);
+	if (ret < 0)
+		return ret;
+
+	if (adf41513_calc_integer_n(st, result) == 0)
+		return 0;
+
+	/* try fractional-N: recompute pfd frequency if necessary */
+	pfd_freq_limit_uhz = min(div_u64(rf_out_uhz, ADF41513_MIN_INT_FRAC_4_5),
+				 ADF41513_MAX_PFD_FREQ_FRAC_N_UHZ);
+	if (pfd_freq_limit_uhz < result->pfd_frequency_uhz) {
+		ret = adf41513_calc_pfd_frequency(st, result, pfd_freq_limit_uhz);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* fixed-modulus attempt */
+	if (adf41513_calc_fixed_mod(st, result) == 0)
+		return 0;
+
+	/* variable-modulus attempt */
+	ret = adf41513_calc_variable_mod(st, result);
+	if (ret < 0) {
+		dev_err(&st->spi->dev,
+			"no valid PLL configuration found for %llu uHz\n",
+			rf_out_uhz);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int adf41513_set_frequency(struct adf41513_state *st, u64 freq_uhz, u16 sync_mask)
+{
+	struct adf41513_pll_settings result;
+	int ret;
+
+	ret = adf41513_calc_pll_settings(st, &result, freq_uhz);
+	if (ret < 0)
+		return ret;
+
+	/* apply computed results to pll settings */
+	st->settings = result;
+
+	dev_dbg(&st->spi->dev,
+		"%s mode: int=%u, frac1=%u, frac2=%u, mod2=%u, fpdf=%llu Hz, prescaler=%s\n",
+		(result.mode == ADF41513_MODE_INTEGER_N) ? "integer-n" :
+		(result.mode == ADF41513_MODE_FIXED_MODULUS) ? "fixed-modulus" : "variable-modulus",
+		result.int_value, result.frac1, result.frac2, result.mod2,
+		div64_u64(result.pfd_frequency_uhz, MICRO),
+		result.prescaler ? "8/9" : "4/5");
+
+	st->regs[ADF41513_REG0] = FIELD_PREP(ADF41513_REG0_INT_MSK,
+					     st->settings.int_value);
+	if (st->settings.mode == ADF41513_MODE_VARIABLE_MODULUS)
+		st->regs[ADF41513_REG0] |= ADF41513_REG0_VAR_MOD_MSK;
+
+	st->regs[ADF41513_REG1] = FIELD_PREP(ADF41513_REG1_FRAC1_MSK,
+					     st->settings.frac1);
+	if (st->settings.mode != ADF41513_MODE_INTEGER_N)
+		st->regs[ADF41513_REG1] |= ADF41513_REG1_DITHER2_MSK;
+
+	st->regs[ADF41513_REG3] = FIELD_PREP(ADF41513_REG3_FRAC2_MSK,
+					     st->settings.frac2);
+	FIELD_MODIFY(ADF41513_REG4_MOD2_MSK, &st->regs[ADF41513_REG4],
+		     st->settings.mod2);
+	FIELD_MODIFY(ADF41513_REG5_R_CNT_MSK, &st->regs[ADF41513_REG5],
+		     st->settings.r_counter);
+	FIELD_MODIFY(ADF41513_REG5_REF_DOUBLER_MSK, &st->regs[ADF41513_REG5],
+		     st->settings.ref_doubler);
+	FIELD_MODIFY(ADF41513_REG5_RDIV2_MSK, &st->regs[ADF41513_REG5],
+		     st->settings.ref_div2);
+	FIELD_MODIFY(ADF41513_REG5_PRESCALER_MSK, &st->regs[ADF41513_REG5],
+		     st->settings.prescaler);
+
+	if (st->settings.mode == ADF41513_MODE_INTEGER_N) {
+		st->regs[ADF41513_REG6] |= ADF41513_REG6_INT_MODE_MSK;
+		st->regs[ADF41513_REG6] &= ~ADF41513_REG6_BLEED_ENABLE_MSK;
+	} else {
+		st->regs[ADF41513_REG6] &= ~ADF41513_REG6_INT_MODE_MSK;
+		st->regs[ADF41513_REG6] |= ADF41513_REG6_BLEED_ENABLE_MSK;
+	}
+
+	return adf41513_sync_config(st, sync_mask | ADF41513_SYNC_REG0);
+}
+
+static int adf41513_suspend(struct adf41513_state *st)
+{
+	st->regs[ADF41513_REG6] |= FIELD_PREP(ADF41513_REG6_POWER_DOWN_MSK, 1);
+	return adf41513_sync_config(st, ADF41513_SYNC_DIFF);
+}
+
+static int adf41513_resume(struct adf41513_state *st)
+{
+	st->regs[ADF41513_REG6] &= ~ADF41513_REG6_POWER_DOWN_MSK;
+	return adf41513_sync_config(st, ADF41513_SYNC_DIFF);
+}
+
+static ssize_t adf41513_read_uhz(struct iio_dev *indio_dev,
+				 uintptr_t private,
+				 const struct iio_chan_spec *chan,
+				 char *buf)
+{
+	struct adf41513_state *st = iio_priv(indio_dev);
+	u64 freq_uhz, int_hz;
+	u32 frac_uhz;
+
+	guard(mutex)(&st->lock);
+
+	switch (private) {
+	case ADF41513_FREQ:
+		freq_uhz = adf41513_pll_get_rate(st);
+		if (st->lock_detect &&
+		    !gpiod_get_value_cansleep(st->lock_detect)) {
+			dev_dbg(&st->spi->dev, "PLL un-locked\n");
+			return -EBUSY;
+		}
+		break;
+	case ADF41513_FREQ_RESOLUTION:
+		freq_uhz = st->data.freq_resolution_uhz;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	int_hz = div_u64_rem(freq_uhz, MICRO, &frac_uhz);
+	return sysfs_emit(buf, "%llu.%06u\n", int_hz, frac_uhz);
+}
+
+static ssize_t adf41513_read_powerdown(struct iio_dev *indio_dev,
+				       uintptr_t private,
+				       const struct iio_chan_spec *chan,
+				       char *buf)
+{
+	struct adf41513_state *st = iio_priv(indio_dev);
+	u32 val;
+
+	guard(mutex)(&st->lock);
+
+	switch (private) {
+	case ADF41513_POWER_DOWN:
+		val = FIELD_GET(ADF41513_REG6_POWER_DOWN_MSK,
+				st->regs_hw[ADF41513_REG6]);
+		return sysfs_emit(buf, "%u\n", val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t adf41513_write_uhz(struct iio_dev *indio_dev,
+				  uintptr_t private,
+				  const struct iio_chan_spec *chan,
+				  const char *buf, size_t len)
+{
+	struct adf41513_state *st = iio_priv(indio_dev);
+	s64 int_hz, frac_uhz;
+	u64 freq_uhz;
+	int ret;
+
+	ret = iio_str_to_fixpoint64(buf, MICRO / 10, &int_hz, &frac_uhz);
+	if (ret)
+		return ret;
+
+	freq_uhz = int_hz * MICRO + frac_uhz;
+	guard(mutex)(&st->lock);
+
+	switch ((u32)private) {
+	case ADF41513_FREQ:
+		ret = adf41513_set_frequency(st, freq_uhz, ADF41513_SYNC_DIFF);
+		break;
+	case ADF41513_FREQ_RESOLUTION:
+		if (freq_uhz == 0 || freq_uhz > ADF41513_MAX_FREQ_RESOLUTION_UHZ)
+			return -EINVAL;
+		st->data.freq_resolution_uhz = freq_uhz;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return ret ?: len;
+}
+
+static ssize_t adf41513_write_powerdown(struct iio_dev *indio_dev,
+					uintptr_t private,
+					const struct iio_chan_spec *chan,
+					const char *buf, size_t len)
+{
+	struct adf41513_state *st = iio_priv(indio_dev);
+	unsigned long readin;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &readin);
+	if (ret)
+		return ret;
+
+	guard(mutex)(&st->lock);
+
+	switch ((u32)private) {
+	case ADF41513_POWER_DOWN:
+		if (readin)
+			ret = adf41513_suspend(st);
+		else
+			ret = adf41513_resume(st);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return ret ?: len;
+}
+
+#define _ADF41513_EXT_PD_INFO(_name, _ident) { \
+	.name = _name, \
+	.read = adf41513_read_powerdown, \
+	.write = adf41513_write_powerdown, \
+	.private = _ident, \
+	.shared = IIO_SEPARATE, \
+}
+
+#define _ADF41513_EXT_UHZ_INFO(_name, _ident) { \
+	.name = _name, \
+	.read = adf41513_read_uhz, \
+	.write = adf41513_write_uhz, \
+	.private = _ident, \
+	.shared = IIO_SEPARATE, \
+}
+
+static const struct iio_chan_spec_ext_info adf41513_ext_info[] = {
+	/*
+	 * Ideally we would use IIO_CHAN_INFO_FREQUENCY, but the device supports
+	 * frequency values greater 2^32 with sub-Hz resolution, i.e. 64-bit
+	 * fixed point with 6 decimal places values are used to represent
+	 * frequencies.
+	 */
+	_ADF41513_EXT_UHZ_INFO("frequency", ADF41513_FREQ),
+	_ADF41513_EXT_UHZ_INFO("frequency_resolution", ADF41513_FREQ_RESOLUTION),
+	_ADF41513_EXT_PD_INFO("powerdown", ADF41513_POWER_DOWN),
+	{ }
+};
+
+static const struct iio_chan_spec adf41513_chan = {
+	.type = IIO_ALTVOLTAGE,
+	.indexed = 1,
+	.output = 1,
+	.channel = 0,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_PHASE),
+	.ext_info = adf41513_ext_info,
+};
+
+static int adf41513_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long info)
+{
+	struct adf41513_state *st = iio_priv(indio_dev);
+	u64 phase_urad;
+	u16 phase_val;
+
+	guard(mutex)(&st->lock);
+
+	switch (info) {
+	case IIO_CHAN_INFO_PHASE:
+		phase_val = FIELD_GET(ADF41513_REG2_PHASE_VAL_MSK,
+				      st->regs_hw[ADF41513_REG2]);
+		phase_urad = (u64)phase_val * ADF41513_MAX_PHASE_MICRORAD;
+		phase_urad >>= 12;
+		/*
+		 * Before the 12-bit rshift phase_urad can be represented with
+		 * 35 bits at most. After the shift it will fit in 32-bit value.
+		 */
+		*val = (u32)phase_urad / MICRO;
+		*val2 = (u32)phase_urad % MICRO;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int adf41513_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long info)
+{
+	struct adf41513_state *st = iio_priv(indio_dev);
+	u64 phase_urad;
+	u16 phase_val;
+
+	guard(mutex)(&st->lock);
+
+	switch (info) {
+	case IIO_CHAN_INFO_PHASE:
+		if (val < 0 || val2 < 0)
+			return -EINVAL;
+
+		phase_urad = (u64)val * MICRO + val2;
+		if (phase_urad >= ADF41513_MAX_PHASE_MICRORAD)
+			return -EINVAL;
+
+		phase_val = DIV_U64_ROUND_CLOSEST(phase_urad << 12,
+						  ADF41513_MAX_PHASE_MICRORAD);
+		phase_val = min(phase_val, ADF41513_MAX_PHASE_VAL);
+		st->regs[ADF41513_REG2] |= ADF41513_REG2_PHASE_ADJ_MSK;
+		FIELD_MODIFY(ADF41513_REG2_PHASE_VAL_MSK,
+			     &st->regs[ADF41513_REG2], phase_val);
+		return adf41513_sync_config(st, ADF41513_SYNC_REG0);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int adf41513_reg_access(struct iio_dev *indio_dev, unsigned int reg,
+			       unsigned int writeval, unsigned int *readval)
+{
+	struct adf41513_state *st = iio_priv(indio_dev);
+
+	if (reg > ADF41513_REG13)
+		return -EINVAL;
+
+	guard(mutex)(&st->lock);
+
+	if (!readval) {
+		if (reg <= ADF41513_REG6)
+			st->settings.mode = ADF41513_MODE_INVALID;
+		st->regs[reg] = writeval & ~0xF; /* Clear control bits */
+		return adf41513_sync_config(st, BIT(reg));
+	}
+
+	*readval = st->regs_hw[reg];
+	return 0;
+}
+
+static const struct iio_info adf41513_info = {
+	.read_raw = adf41513_read_raw,
+	.write_raw = adf41513_write_raw,
+	.debugfs_reg_access = &adf41513_reg_access,
+};
+
+static int adf41513_parse_fw(struct adf41513_state *st)
+{
+	struct device *dev = &st->spi->dev;
+	u32 tmp, cp_resistance, cp_current;
+	int ret;
+
+	tmp = ADF41510_MAX_RF_FREQ_HZ / MEGA;
+	device_property_read_u32(dev, "adi,power-up-frequency-mhz", &tmp);
+	st->data.power_up_frequency_hz = (u64)tmp * MEGA;
+	if (st->data.power_up_frequency_hz < ADF41513_MIN_RF_FREQ_HZ ||
+	    st->data.power_up_frequency_hz > ADF41513_MAX_RF_FREQ_HZ)
+		return dev_err_probe(dev, -ERANGE,
+				     "power-up frequency %llu Hz out of range\n",
+				     st->data.power_up_frequency_hz);
+
+	tmp = ADF41513_MIN_R_CNT;
+	device_property_read_u32(dev, "adi,reference-div-factor", &tmp);
+	if (tmp < ADF41513_MIN_R_CNT || tmp > ADF41513_MAX_R_CNT)
+		return dev_err_probe(dev, -ERANGE,
+				     "invalid reference div factor %u\n", tmp);
+	st->data.ref_div_factor = tmp;
+
+	st->data.ref_doubler_en = device_property_read_bool(dev, "adi,reference-doubler-enable");
+	st->data.ref_div2_en = device_property_read_bool(dev, "adi,reference-div2-enable");
+
+	cp_resistance = ADF41513_DEFAULT_R_SET;
+	device_property_read_u32(dev, "adi,charge-pump-resistor-ohms", &cp_resistance);
+	if (cp_resistance < ADF41513_MIN_R_SET || cp_resistance > ADF41513_MAX_R_SET)
+		return dev_err_probe(dev, -ERANGE, "R_SET %u Ohms out of range\n", cp_resistance);
+
+	st->data.charge_pump_voltage_mv = ADF41513_DEFAULT_CP_VOLTAGE_mV;
+	ret = device_property_read_u32(dev, "adi,charge-pump-current-microamp", &cp_current);
+	if (!ret) {
+		tmp = DIV_ROUND_CLOSEST(cp_current * cp_resistance, MILLI); /* convert to mV */
+		if (tmp < ADF41513_MIN_CP_VOLTAGE_mV || tmp > ADF41513_MAX_CP_VOLTAGE_mV)
+			return dev_err_probe(dev, -ERANGE, "I_CP %u uA (%u Ohms) out of range\n",
+					     cp_current, cp_resistance);
+		st->data.charge_pump_voltage_mv = tmp;
+	}
+
+	st->data.phase_detector_polarity =
+		device_property_read_bool(dev, "adi,phase-detector-polarity-positive-enable");
+
+	st->data.logic_lvl_1v8_en = device_property_read_bool(dev, "adi,logic-level-1v8-enable");
+
+	tmp = ADF41513_LD_COUNT_MIN;
+	device_property_read_u32(dev, "adi,lock-detector-count", &tmp);
+	if (tmp < ADF41513_LD_COUNT_FAST_MIN || tmp > ADF41513_LD_COUNT_MAX ||
+	    !is_power_of_2(tmp))
+		return dev_err_probe(dev, -ERANGE,
+				     "invalid lock detect count: %u\n", tmp);
+	st->data.lock_detect_count = tmp;
+
+	st->data.freq_resolution_uhz = MICROHZ_PER_HZ;
+
+	return 0;
+}
+
+static int adf41513_setup(struct adf41513_state *st)
+{
+	u32 tmp;
+
+	memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));
+
+	/* assuming DLD pin is used for lock detection */
+	st->regs[ADF41513_REG5] = FIELD_PREP(ADF41513_REG5_DLD_MODES_MSK,
+					     ADF41513_DLD_DIG_LD);
+
+	tmp = DIV_ROUND_CLOSEST(st->data.charge_pump_voltage_mv, ADF41513_MIN_CP_VOLTAGE_mV);
+	st->regs[ADF41513_REG5] |= FIELD_PREP(ADF41513_REG5_CP_CURRENT_MSK, tmp - 1);
+
+	st->regs[ADF41513_REG6] = ADF41513_REG6_ABP_MSK |
+				  ADF41513_REG6_LOL_ENABLE_MSK |
+				  ADF41513_REG6_SD_RESET_MSK;
+	if (st->data.phase_detector_polarity)
+		st->regs[ADF41513_REG6] |= ADF41513_REG6_PD_POLARITY_MSK;
+
+	st->regs[ADF41513_REG7] = FIELD_PREP(ADF41513_REG7_PS_BIAS_MSK,
+					     ADF41513_PS_BIAS_INIT);
+	tmp = ilog2(st->data.lock_detect_count);
+	if (st->data.lock_detect_count < ADF41513_LD_COUNT_FAST_LIMIT) {
+		tmp -= const_ilog2(ADF41513_LD_COUNT_FAST_MIN);
+		st->regs[ADF41513_REG7] |= ADF41513_REG7_LD_CLK_SEL_MSK;
+	} else {
+		tmp -= const_ilog2(ADF41513_LD_COUNT_MIN);
+	}
+	st->regs[ADF41513_REG7] |= FIELD_PREP(ADF41513_REG7_LD_COUNT_MSK, tmp);
+
+	st->regs[ADF41513_REG11] = ADF41513_REG11_POWER_DOWN_SEL_MSK;
+	st->regs[ADF41513_REG12] = FIELD_PREP(ADF41513_REG12_LOGIC_LEVEL_MSK,
+					      st->data.logic_lvl_1v8_en ? 0 : 1);
+
+	/* perform initialization sequence with power-up frequency */
+	return adf41513_set_frequency(st, st->data.power_up_frequency_hz * MICRO,
+				      ADF41513_SYNC_ALL);
+}
+
+static void adf41513_power_down(void *data)
+{
+	struct adf41513_state *st = data;
+
+	adf41513_suspend(st);
+	gpiod_set_value_cansleep(st->chip_enable, 0);
+}
+
+static int adf41513_pm_suspend(struct device *dev)
+{
+	return adf41513_suspend(dev_get_drvdata(dev));
+}
+
+static int adf41513_pm_resume(struct device *dev)
+{
+	return adf41513_resume(dev_get_drvdata(dev));
+}
+
+static const struct adf41513_chip_info adf41510_chip_info = {
+	.name = "adf41510",
+	.max_rf_freq_hz = ADF41510_MAX_RF_FREQ_HZ,
+	.has_prescaler_8_9 = false,
+};
+
+static const struct adf41513_chip_info adf41513_chip_info = {
+	.name = "adf41513",
+	.max_rf_freq_hz = ADF41513_MAX_RF_FREQ_HZ,
+	.has_prescaler_8_9 = true,
+};
+
+static int adf41513_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct iio_dev *indio_dev;
+	struct adf41513_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	st->spi = spi;
+	st->chip_info = spi_get_device_match_data(spi);
+	if (!st->chip_info)
+		return -EINVAL;
+
+	spi_set_drvdata(spi, st);
+
+	st->ref_clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(st->ref_clk))
+		return PTR_ERR(st->ref_clk);
+
+	st->ref_freq_hz = clk_get_rate(st->ref_clk);
+	if (st->ref_freq_hz < ADF41513_MIN_REF_FREQ_HZ ||
+	    st->ref_freq_hz > ADF41513_MAX_REF_FREQ_HZ)
+		return dev_err_probe(dev, -ERANGE,
+				     "reference frequency %u Hz out of range\n",
+				     st->ref_freq_hz);
+
+	ret = adf41513_parse_fw(st);
+	if (ret)
+		return ret;
+
+	ret = devm_regulator_bulk_get_enable(dev,
+					     ARRAY_SIZE(adf41513_power_supplies),
+					     adf41513_power_supplies);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to get and enable regulators\n");
+
+	st->chip_enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(st->chip_enable))
+		return dev_err_probe(dev, PTR_ERR(st->chip_enable),
+				     "fail to request chip enable GPIO\n");
+
+	st->lock_detect = devm_gpiod_get_optional(dev, "lock-detect", GPIOD_IN);
+	if (IS_ERR(st->lock_detect))
+		return dev_err_probe(dev, PTR_ERR(st->lock_detect),
+				     "fail to request lock detect GPIO\n");
+
+	ret = devm_mutex_init(dev, &st->lock);
+	if (ret)
+		return ret;
+
+	indio_dev->name = st->chip_info->name;
+	indio_dev->info = &adf41513_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = &adf41513_chan;
+	indio_dev->num_channels = 1;
+
+	ret = adf41513_setup(st);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to setup device\n");
+
+	ret = devm_add_action_or_reset(dev, adf41513_power_down, st);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to add power down action\n");
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct spi_device_id adf41513_id[] = {
+	{"adf41510", (kernel_ulong_t)&adf41510_chip_info},
+	{"adf41513", (kernel_ulong_t)&adf41513_chip_info},
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, adf41513_id);
+
+static const struct of_device_id adf41513_of_match[] = {
+	{ .compatible = "adi,adf41510", .data = &adf41510_chip_info },
+	{ .compatible = "adi,adf41513", .data = &adf41513_chip_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, adf41513_of_match);
+
+static DEFINE_SIMPLE_DEV_PM_OPS(adf41513_pm_ops, adf41513_pm_suspend, adf41513_pm_resume);
+
+static struct spi_driver adf41513_driver = {
+	.driver = {
+		.name = "adf41513",
+		.pm = pm_ptr(&adf41513_pm_ops),
+		.of_match_table = adf41513_of_match,
+	},
+	.probe = adf41513_probe,
+	.id_table = adf41513_id,
+};
+module_spi_driver(adf41513_driver);
+
+MODULE_AUTHOR("Rodrigo Alencar <rodrigo.alencar@analog.com>");
+MODULE_DESCRIPTION("Analog Devices ADF41513 PLL Frequency Synthesizer");
+MODULE_LICENSE("GPL");

-- 
2.43.0

[PATCH v9 6/9] iio: frequency: adf41513: handle LE synchronization feature

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

When LE sync is enabled, it is must be set after powering up and must be
disabled when powering down. It is recommended when using the PLL as
a frequency synthesizer, where reference signal will always be present
while the device is being configured.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 drivers/iio/frequency/adf41513.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/frequency/adf41513.c b/drivers/iio/frequency/adf41513.c
index 5a0682667d1f..caae9d53c3e2 100644
--- a/drivers/iio/frequency/adf41513.c
+++ b/drivers/iio/frequency/adf41513.c
@@ -222,6 +222,7 @@ struct adf41513_data {
 	bool phase_detector_polarity;
 
 	bool logic_lvl_1v8_en;
+	bool le_sync_en;
 };
 
 struct adf41513_pll_settings {
@@ -634,13 +635,27 @@ static int adf41513_set_frequency(struct adf41513_state *st, u64 freq_uhz, u16 s
 static int adf41513_suspend(struct adf41513_state *st)
 {
 	st->regs[ADF41513_REG6] |= FIELD_PREP(ADF41513_REG6_POWER_DOWN_MSK, 1);
+	st->regs[ADF41513_REG12] &= ~ADF41513_REG12_LE_SELECT_MSK;
 	return adf41513_sync_config(st, ADF41513_SYNC_DIFF);
 }
 
 static int adf41513_resume(struct adf41513_state *st)
 {
+	int ret;
+
 	st->regs[ADF41513_REG6] &= ~ADF41513_REG6_POWER_DOWN_MSK;
-	return adf41513_sync_config(st, ADF41513_SYNC_DIFF);
+	ret = adf41513_sync_config(st, ADF41513_SYNC_DIFF);
+	if (ret)
+		return ret;
+
+	if (st->data.le_sync_en) {
+		st->regs[ADF41513_REG12] |= ADF41513_REG12_LE_SELECT_MSK;
+		ret = adf41513_sync_config(st, ADF41513_SYNC_DIFF);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
 }
 
 static ssize_t adf41513_read_uhz(struct iio_dev *indio_dev,
@@ -933,6 +948,8 @@ static int adf41513_parse_fw(struct adf41513_state *st)
 				     "invalid lock detect count: %u\n", tmp);
 	st->data.lock_detect_count = tmp;
 
+	/* load enable sync */
+	st->data.le_sync_en = device_property_read_bool(dev, "adi,le-sync-enable");
 	st->data.freq_resolution_uhz = MICROHZ_PER_HZ;
 
 	return 0;
@@ -940,6 +957,7 @@ static int adf41513_parse_fw(struct adf41513_state *st)
 
 static int adf41513_setup(struct adf41513_state *st)
 {
+	int ret;
 	u32 tmp;
 
 	memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));
@@ -973,8 +991,19 @@ static int adf41513_setup(struct adf41513_state *st)
 					      st->data.logic_lvl_1v8_en ? 0 : 1);
 
 	/* perform initialization sequence with power-up frequency */
-	return adf41513_set_frequency(st, st->data.power_up_frequency_hz * MICRO,
-				      ADF41513_SYNC_ALL);
+	ret = adf41513_set_frequency(st, st->data.power_up_frequency_hz * MICRO,
+				     ADF41513_SYNC_ALL);
+	if (ret)
+		return ret;
+
+	if (st->data.le_sync_en) {
+		st->regs[ADF41513_REG12] |= ADF41513_REG12_LE_SELECT_MSK;
+		ret = adf41513_sync_config(st, ADF41513_SYNC_DIFF);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 static void adf41513_power_down(void *data)

-- 
2.43.0

[PATCH v9 7/9] iio: frequency: adf41513: features on frequency change

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

Set Bleed current when PFD frequency changes (bleed enabled when in
fractional mode). Set lock detector window size, handling bias and
precision. Add phase resync support, setting clock dividers when
PFD frequency changes.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 drivers/iio/frequency/adf41513.c | 100 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/drivers/iio/frequency/adf41513.c b/drivers/iio/frequency/adf41513.c
index caae9d53c3e2..f6ed42df26d6 100644
--- a/drivers/iio/frequency/adf41513.c
+++ b/drivers/iio/frequency/adf41513.c
@@ -20,6 +20,7 @@
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/spi/spi.h>
+#include <linux/time64.h>
 #include <linux/types.h>
 #include <linux/units.h>
 
@@ -213,6 +214,7 @@ struct adf41513_chip_info {
 struct adf41513_data {
 	u64 power_up_frequency_hz;
 	u64 freq_resolution_uhz;
+	u32 phase_resync_period_ns;
 	u32 charge_pump_voltage_mv;
 	u32 lock_detect_count;
 
@@ -271,6 +273,16 @@ struct adf41513_state {
 	struct adf41513_pll_settings settings;
 };
 
+static const u16 adf41513_ld_window_x10_ns[] = {
+	9, 12, 16, 17, 21, 28, 29, 35,			/* 0 - 7 */
+	43, 47, 49, 52, 70, 79, 115,			/* 8 - 14 */
+};
+
+static const u8 adf41513_ldp_bias[] = {
+	0xC, 0xD, 0xE, 0x8, 0x9, 0x4, 0xA, 0x5,		/* 0 - 7 */
+	0x0, 0x6, 0xB, 0x1, 0x2, 0x7, 0x3,		/* 8 - 14 */
+};
+
 static const char * const adf41513_power_supplies[] = {
 	"avdd1", "avdd2", "avdd3", "avdd4", "avdd5", "vp",
 };
@@ -578,9 +590,82 @@ static int adf41513_calc_pll_settings(struct adf41513_state *st,
 	return 0;
 }
 
+static void adf41513_set_bleed_val(struct adf41513_state *st)
+{
+	u32 bleed_value, cp_index;
+
+	if (st->data.phase_detector_polarity)
+		bleed_value = 90;
+	else
+		bleed_value = 144;
+
+	cp_index = 1 + FIELD_GET(ADF41513_REG5_CP_CURRENT_MSK,
+				 st->regs[ADF41513_REG5]);
+	bleed_value = div64_u64(st->settings.pfd_frequency_uhz * cp_index * bleed_value,
+				1600ULL * MEGA * MICROHZ_PER_HZ);
+
+	FIELD_MODIFY(ADF41513_REG6_BLEED_CURRENT_MSK, &st->regs[ADF41513_REG6],
+		     bleed_value);
+}
+
+static void adf41513_set_ld_window(struct adf41513_state *st)
+{
+	/*
+	 * The ideal lock detector window size is halfway between the max
+	 * window, set by the phase comparison period t_PFD = (1 / f_PFD),
+	 * and the minimum is set by (I_BLEED/I_CP) × t_PFD
+	 */
+	u16 ld_window_10x_ns = div64_u64(10ULL * NSEC_PER_SEC * MICROHZ_PER_HZ,
+					 st->settings.pfd_frequency_uhz << 1);
+	u8 ld_idx, ldp, ld_bias;
+
+	if (st->settings.mode != ADF41513_MODE_INTEGER_N) {
+		/* account for bleed current (deduced from eq.6 and eq.7) */
+		if (st->data.phase_detector_polarity)
+			ld_window_10x_ns += 4;
+		else
+			ld_window_10x_ns += 6;
+	}
+
+	ld_idx = find_closest(ld_window_10x_ns, adf41513_ld_window_x10_ns,
+			      ARRAY_SIZE(adf41513_ld_window_x10_ns));
+	ldp = (adf41513_ldp_bias[ld_idx] >> 2) & 0x3;
+	ld_bias = adf41513_ldp_bias[ld_idx] & 0x3;
+
+	FIELD_MODIFY(ADF41513_REG6_LDP_MSK, &st->regs[ADF41513_REG6], ldp);
+	FIELD_MODIFY(ADF41513_REG9_LD_BIAS_MSK, &st->regs[ADF41513_REG9], ld_bias);
+}
+
+static void adf41513_set_phase_resync(struct adf41513_state *st)
+{
+	u32 total_div, clk1_div, clk2_div;
+
+	if (!st->data.phase_resync_period_ns)
+		return;
+
+	/* assuming both clock dividers hold similar values */
+	total_div = mul_u64_u64_div_u64(st->settings.pfd_frequency_uhz,
+					st->data.phase_resync_period_ns,
+					1ULL * MICROHZ_PER_HZ * NSEC_PER_SEC);
+	clk1_div = clamp(int_sqrt(total_div), 1,
+			 ADF41513_MAX_CLK_DIVIDER);
+	clk2_div = clamp(DIV_ROUND_CLOSEST(total_div, clk1_div), 1,
+			 ADF41513_MAX_CLK_DIVIDER);
+
+	FIELD_MODIFY(ADF41513_REG5_CLK1_DIV_MSK, &st->regs[ADF41513_REG5],
+		     clk1_div);
+	FIELD_MODIFY(ADF41513_REG7_CLK2_DIV_MSK, &st->regs[ADF41513_REG7],
+		     clk2_div);
+
+	/* enable phase resync */
+	st->regs[ADF41513_REG7] |= ADF41513_REG7_CLK_DIV_MODE_MSK;
+}
+
 static int adf41513_set_frequency(struct adf41513_state *st, u64 freq_uhz, u16 sync_mask)
 {
 	struct adf41513_pll_settings result;
+	bool pfd_change = false;
+	bool mode_change = false;
 	int ret;
 
 	ret = adf41513_calc_pll_settings(st, &result, freq_uhz);
@@ -588,6 +673,8 @@ static int adf41513_set_frequency(struct adf41513_state *st, u64 freq_uhz, u16 s
 		return ret;
 
 	/* apply computed results to pll settings */
+	pfd_change = st->settings.pfd_frequency_uhz != result.pfd_frequency_uhz;
+	mode_change = st->settings.mode != result.mode;
 	st->settings = result;
 
 	dev_dbg(&st->spi->dev,
@@ -629,6 +716,14 @@ static int adf41513_set_frequency(struct adf41513_state *st, u64 freq_uhz, u16 s
 		st->regs[ADF41513_REG6] |= ADF41513_REG6_BLEED_ENABLE_MSK;
 	}
 
+	if (pfd_change) {
+		adf41513_set_bleed_val(st);
+		adf41513_set_phase_resync(st);
+	}
+
+	if (pfd_change || mode_change)
+		adf41513_set_ld_window(st);
+
 	return adf41513_sync_config(st, sync_mask | ADF41513_SYNC_REG0);
 }
 
@@ -938,6 +1033,11 @@ static int adf41513_parse_fw(struct adf41513_state *st)
 	st->data.phase_detector_polarity =
 		device_property_read_bool(dev, "adi,phase-detector-polarity-positive-enable");
 
+	st->data.phase_resync_period_ns = 0;
+	ret = device_property_read_u32(dev, "adi,phase-resync-period-ns", &tmp);
+	if (!ret)
+		st->data.phase_resync_period_ns = tmp;
+
 	st->data.logic_lvl_1v8_en = device_property_read_bool(dev, "adi,logic-level-1v8-enable");
 
 	tmp = ADF41513_LD_COUNT_MIN;

-- 
2.43.0

[PATCH v9 8/9] docs: iio: add documentation for adf41513 driver

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

Add documentation for ADF41513 driver, which describes the device
driver files and shows how userspace may consume the ABI for various
tasks.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 Documentation/iio/adf41513.rst | 199 +++++++++++++++++++++++++++++++++++++++++
 Documentation/iio/index.rst    |   1 +
 MAINTAINERS                    |   1 +
 3 files changed, 201 insertions(+)

diff --git a/Documentation/iio/adf41513.rst b/Documentation/iio/adf41513.rst
new file mode 100644
index 000000000000..4193c825b532
--- /dev/null
+++ b/Documentation/iio/adf41513.rst
@@ -0,0 +1,199 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============
+ADF41513 driver
+===============
+
+This driver supports Analog Devices' ADF41513 and similar SPI PLL frequency
+synthesizers.
+
+1. Supported devices
+====================
+
+* `ADF41510 <https://www.analog.com/ADF41510>`_
+* `ADF41513 <https://www.analog.com/ADF41513>`_
+
+The ADF41513 is an ultralow noise frequency synthesizer that can be used to
+implement local oscillators (LOs) as high as 26.5 GHz in the upconversion and
+downconversion sections of wireless receivers and transmitters. The ADF41510
+is a similar device that supports frequencies up to 10 GHz.
+
+Both devices support integer-N and fractional-N operation modes, providing
+excellent phase noise performance and flexible frequency generation
+capabilities.
+
+Key Features:
+
+- **ADF41510**: 1 GHz to 10 GHz frequency range
+- **ADF41513**: 1 GHz to 26.5 GHz frequency range
+- Integer-N and fractional-N operation modes
+- Ultra-low phase noise (-235 dBc/Hz integer-N, -231 dBc/Hz fractional-N)
+- High maximum PFD frequency (250 MHz integer-N, 125 MHz fractional-N)
+- 25-bit fixed modulus or 49-bit variable modulus fractional modes
+- Programmable charge pump currents with 16x range
+- Digital lock detect functionality
+- Phase resync capability for consistent output phase
+
+2. Device attributes
+====================
+
+The ADF41513 driver provides the following IIO extended attributes for
+frequency control and monitoring:
+
+Each IIO device has a device folder under ``/sys/bus/iio/devices/iio:deviceX``,
+where X is the IIO index of the device. Under these folders reside a set of
+device files that provide access to the synthesizer's functionality.
+
+The following table shows the ADF41513 related device files:
+
++----------------------+-------------------------------------------------------+
+| Device file          | Description                                           |
++======================+=======================================================+
+| frequency            | RF output frequency control and readback (Hz)         |
++----------------------+-------------------------------------------------------+
+| frequency_resolution | Target frequency resolution control (Hz)              |
++----------------------+-------------------------------------------------------+
+| powerdown            | Power management control (0=active, 1=power down)     |
++----------------------+-------------------------------------------------------+
+| phase                | RF output phase adjustment and readback (radians)     |
++----------------------+-------------------------------------------------------+
+
+2.1 Frequency Control
+----------------------
+
+The ``frequency`` attribute controls the RF output frequency with sub-Hz
+precision. The driver automatically selects between integer-N and fractional-N
+modes to achieve the requested frequency with the best possible phase noise
+performance.
+
+**Supported ranges:**
+
+- **ADF41510**: 1,000,000,000 Hz to 10,000,000,000 Hz (1 GHz to 10 GHz)
+- **ADF41513**: 1,000,000,000 Hz to 26,500,000,000 Hz (1 GHz to 26.5 GHz)
+
+The frequency is specified in Hz, for sub-Hz precision use decimal notation.
+For example, 12.102 GHz would be written as "12102000000.000000".
+
+2.2 Frequency Resolution Control
+--------------------------------
+
+The ``frequency_resolution`` attribute controls the target frequency resolution
+that the driver attempts to achieve. This affects the choice between integer-N
+and fractional-N modes, including fixed modulus (25-bit) and variable modulus
+(49-bit) fractional-N modes:
+
+- **Integer-N**: Resolution = f_PFD
+- **Fixed modulus**: Resolution = f_PFD / 2^25 (~3 Hz with 100 MHz PFD)
+- **Variable modulus**: Resolution = f_PFD / 2^49 (µHz resolution possible)
+
+Default resolution is 1 Hz (1,000,000 µHz).
+
+2.3 Phase adjustment
+--------------------
+
+The ``phase`` attribute allows adjustment of the output phase in radians.
+Setting this attribute enables phase adjustment. It can be set from 0 to 2*pi
+radians. Reading this attribute returns the current phase offset of the output
+signal. To create a consistent phase relationship with the reference signal,
+the phase resync feature needs to be enabled by setting a non-zero value to the
+``adi,phase-resync-period-ns`` device property, which triggers a phase
+resynchronization after locking is achieved.
+
+3. Operating modes
+==================
+
+3.1 Integer-N Mode
+------------------
+
+When the requested frequency can be achieved as an integer multiple of the PFD
+frequency (within the specified resolution tolerance), the driver automatically
+selects integer-N mode for optimal phase noise performance.
+
+In integer-N mode:
+
+- Phase noise: -235 dBc/Hz normalized floor
+- Frequency resolution: f_PFD (same as PFD frequency)
+- Maximum PFD frequency: 250 MHz
+- Bleed current: Disabled
+
+3.2 Fractional-N Mode
+---------------------
+
+When sub-integer frequency steps are required, the driver automatically selects
+fractional-N mode using either fixed or variable modulus.
+
+**Fixed Modulus (25-bit)**:
+
+- Used when variable modulus is not required
+- Resolution: f_PFD / 2^25
+- Simpler implementation, faster settling
+
+**Variable Modulus (49-bit)**:
+
+- Used for maximum resolution requirements
+- Resolution: f_PFD / 2^49 (theoretical)
+- Exact frequency synthesis capability
+
+In fractional-N mode:
+
+- Phase noise: -231 dBc/Hz normalized floor
+- Maximum PFD frequency: 125 MHz
+- Bleed current: Automatically enabled and optimized
+- Dithering: Enabled to reduce fractional spurs
+
+3.3 Automatic Mode Selection
+----------------------------
+
+The driver automatically selects the optimal operating mode based on:
+
+1. **Frequency accuracy requirements**: Determined by frequency_resolution setting
+2. **Phase noise optimization**: Integer-N preferred when possible
+3. **PFD frequency constraints**: Different limits for integer vs fractional modes
+4. **Prescaler selection**: Automatic 4/5 vs 8/9 prescaler selection based on frequency
+
+4. Usage examples
+=================
+
+4.1 Basic Frequency Setting
+----------------------------
+
+Set output frequency to 12.102 GHz:
+
+.. code-block:: bash
+
+    root:/sys/bus/iio/devices/iio:device0> echo 12102000000 > out_altvoltage0_frequency
+
+Read current frequency:
+
+.. code-block:: bash
+
+    root:/sys/bus/iio/devices/iio:device0> cat out_altvoltage0_frequency
+    12101999999.582767
+
+4.2 High Resolution Frequency Control
+-------------------------------------
+
+Configure for sub-Hz resolution and set a precise frequency:
+
+.. code-block:: bash
+
+    # Set resolution to 0.1 Hz (100,000 µHz)
+    root:/sys/bus/iio/devices/iio:device0> echo 0.1 > out_altvoltage0_frequency_resolution
+
+    # Set frequency to 12.102 GHz (1 µHz precision)
+    root:/sys/bus/iio/devices/iio:device0> echo 12102000000 > out_altvoltage0_frequency
+    root:/sys/bus/iio/devices/iio:device0> cat out_altvoltage0_frequency
+    12101999999.980131
+
+4.3 Monitor Lock Status
+-----------------------
+
+When lock detect GPIO is configured, check if PLL is locked:
+
+.. code-block:: bash
+
+    # Read frequency - will return error if not locked
+    root:/sys/bus/iio/devices/iio:device0> cat out_altvoltage0_frequency
+
+If the PLL is not locked, the frequency read will return ``-EBUSY`` (Device or
+resource busy).
diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst
index ba3e609c6a13..605871765c78 100644
--- a/Documentation/iio/index.rst
+++ b/Documentation/iio/index.rst
@@ -30,6 +30,7 @@ Industrial I/O Kernel Drivers
    ad7625
    ad7944
    ade9000
+   adf41513
    adis16475
    adis16480
    adis16550
diff --git a/MAINTAINERS b/MAINTAINERS
index fb723e40f1a9..d0573165edad 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1660,6 +1660,7 @@ L:	linux-iio@vger.kernel.org
 S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/frequency/adi,adf41513.yaml
+F:	Documentation/iio/adf41513.rst
 F:	drivers/iio/frequency/adf41513.c
 
 ANALOG DEVICES INC ADF4377 DRIVER

-- 
2.43.0

[PATCH v9 9/9] Documentation: ABI: testing: add common ABI file for iio/frequency

[Rodrigo Alencar via B4 Relay]

From: Rodrigo Alencar <rodrigo.alencar@analog.com>

Add ABI documentation file for PLL/DDS devices with frequency_resolution
sysfs entry attribute used by both ADF4350 and ADF41513.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
---
 Documentation/ABI/testing/sysfs-bus-iio-frequency         | 11 +++++++++++
 Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350 | 10 ----------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-frequency b/Documentation/ABI/testing/sysfs-bus-iio-frequency
new file mode 100644
index 000000000000..1ce8ae578fd6
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-frequency
@@ -0,0 +1,11 @@
+What:		/sys/bus/iio/devices/iio:deviceX/out_altvoltageY_frequency_resolution
+KernelVersion:	6.20
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Stores channel Y frequency resolution/channel spacing in Hz for PLL
+		devices. The given value directly influences the operating mode when
+		fractional-N synthesis is required, as it derives values for
+		configurable modulus parameters used in the calculation of the output
+		frequency. It is assumed that the algorithm that is used to compute
+		the various dividers, is able to generate proper values for multiples
+		of channel spacing.
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350 b/Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350
index 1254457a726e..76987a119feb 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350
+++ b/Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350
@@ -1,13 +1,3 @@
-What:		/sys/bus/iio/devices/iio:deviceX/out_altvoltageY_frequency_resolution
-KernelVersion:	3.4.0
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Stores channel Y frequency resolution/channel spacing in Hz.
-		The value given directly influences the MODULUS used by
-		the fractional-N PLL. It is assumed that the algorithm
-		that is used to compute the various dividers, is able to
-		generate proper values for multiples of channel spacing.
-
 What:		/sys/bus/iio/devices/iio:deviceX/out_altvoltageY_refin_frequency
 KernelVersion:	3.4.0
 Contact:	linux-iio@vger.kernel.org

-- 
2.43.0

Re: [PATCH v9 0/9] ADF41513/ADF41510 PLL frequency synthesizers

[Jonathan Cameron]

On Fri, 20 Mar 2026 16:27:25 +0000
Rodrigo Alencar via B4 Relay <devnull+rodrigo.alencar.analog.com@kernel.org> wrote:

> This patch series adds support for the Analog Devices ADF41513 and ADF41510
> ultralow noise PLL frequency synthesizers. These devices are designed for
> implementing local oscillators (LOs) in high-frequency applications.
> The ADF41513 covers frequencies from 1 GHz to 26.5 GHz, while the ADF41510
> operates from 1 GHz to 10 GHz.
> 
> Key features supported by this driver:
> - Integer-N and fractional-N operation modes
> - High maximum PFD frequency (250 MHz integer-N, 125 MHz fractional-N)
> - 25-bit fixed modulus or 49-bit variable modulus fractional modes
> - Digital lock detect functionality
> - Phase resync capability for consistent output phase
> - Load Enable vs Reference signal syncronization
> 
> The series includes:
> 1. PLL driver implementation
> 2. Device tree bindings documentation
> 3. IIO ABI documentation
> 
> Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
> ---
> Changes in v9:
> - Expose simple_strntoull() in a safer prototype instead of new kstrntoull()
I'm leaving this part to the experts.  Other than that aspect, I took
another look through the driver and all looks good to me.

Thanks,

Jonathan

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[Petr Mladek]

On Fri 2026-03-20 16:27:27, Rodrigo Alencar via B4 Relay wrote:
> From: Rodrigo Alencar <rodrigo.alencar@analog.com>
> 
> Expose simple_strntoull(), by addressing its FIXME, i.e. its prototype is
> slightly changed so that -ERANGE or -EINVAL can be evaluated by the user.
> Flow of the function is not changed and error value is returned in the
> end. Unsafe internal wrapper is created to reduce amount of changes.
> 
> --- a/include/linux/kstrtox.h
> +++ b/include/linux/kstrtox.h
> @@ -148,4 +148,8 @@ extern long simple_strtol(const char *,char **,unsigned int);
>  extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
>  extern long long simple_strtoll(const char *,char **,unsigned int);
>  
> +extern ssize_t __must_check simple_strntoull(const char *startp, const char **endp,
> +					     unsigned int base, size_t max_chars,
> +					     unsigned long long *res);

Sigh, naming is hard. I personally find it a bit confusing that the
name is too similar to the unsafe API.

IMHO, the semantic of the new API is closer to kstrtoull().
It just limits the size, so I would call it kstrntoull().

Also I would use int as the return parameter, see below.


>  #endif	/* _LINUX_KSTRTOX_H */
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 800b8ac49f53..6fb880f4013b 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -75,25 +75,66 @@ enum hash_pointers_policy {
>  };
>  static enum hash_pointers_policy hash_pointers_mode __initdata;
>  
> +/**
> + * simple_strntoull - convert a string to an unsigned long long with a character limit
> + *
> + * @startp: The start of the string
> + * @endp: A pointer to the end of the parsed string will be placed here

I would write:

  * @endp: A pointer to the end of the parsed string (output)

> + * @base: The number base to use
> + * @max_chars: The maximum number of characters to parse
> + * @res: Where to write the result of the conversion on success

Nit: I would omit "on success" *res value is set to 0 on failure.
     Instead, I would write:

  * @res: Result of the conversion (output)

> + *
> + * Returns amount of processed characters on success, -ERANGE on overflow and
> + * -EINVAL on parsing error.
> + */
>  noinline
> -static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars)
> +ssize_t simple_strntoull(const char *startp, const char **endp,
> +			 unsigned int base, size_t max_chars,
> +			 unsigned long long *res)

It might be enoungh to use "int" for the return value. The number
of proceed characters is pretty limited by definition. And it
would be similar to vsnprintf(), kstrtoull(), ...

I guess that you wanted to match the "size_t max_chars" parameter.
It makes some sense as well.

Please, use "int" especially if we agreed to call the new API
kstrntoull().

>  {
>  	const char *cp;
> -	unsigned long long result = 0ULL;
>  	size_t prefix_chars;
>  	unsigned int rv;
> +	ssize_t ret;
>  
>  	cp = _parse_integer_fixup_radix(startp, &base);
>  	prefix_chars = cp - startp;
>  	if (prefix_chars < max_chars) {
> -		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
> -		/* FIXME */
> +		rv = _parse_integer_limit(cp, base, res, max_chars - prefix_chars);
> +		if (rv & KSTRTOX_OVERFLOW)
> +			ret = -ERANGE;
> +		else if (rv == 0)
> +			ret = -EINVAL;
> +		else
> +			ret = rv + prefix_chars;
>  		cp += (rv & ~KSTRTOX_OVERFLOW);
>  	} else {
>  		/* Field too short for prefix + digit, skip over without converting */
>  		cp = startp + max_chars;
> +		ret = -EINVAL;
> +		*res = 0ULL;
>  	}
>  
> +	if (endp)
> +		*endp = cp;
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(simple_strntoull);
> +
> +/* unsafe_strntoull ignores simple_strntoull() return value and endp const qualifier */
> +inline
> +static unsigned long long unsafe_strntoull(const char *startp, char **endp,
> +					   unsigned int base, size_t max_chars)
> +{
> +	unsigned long long result;
> +	const char *cp;
> +
> +#pragma GCC diagnostic push
> +#pragma GCC diagnostic ignored "-Wunused-result"
> +	simple_strntoull(startp, &cp, base, max_chars, &result);
> +#pragma GCC diagnostic pop
> +
>  	if (endp)
>  		*endp = (char *)cp;

IMHO, we do not need local "cp". We could simply pass the endp
to the new simple_strntoull. Or do I miss anything?

Best Regards,
Petr

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[Andy Shevchenko]

On Fri, Mar 27, 2026 at 09:45:17AM +0100, Petr Mladek wrote:
> On Fri 2026-03-20 16:27:27, Rodrigo Alencar via B4 Relay wrote:

...

> > +extern ssize_t __must_check simple_strntoull(const char *startp, const char **endp,
> > +					     unsigned int base, size_t max_chars,
> > +					     unsigned long long *res);
> 
> Sigh, naming is hard. I personally find it a bit confusing that the
> name is too similar to the unsafe API.
> 
> IMHO, the semantic of the new API is closer to kstrtoull().
> It just limits the size, so I would call it kstrntoull().

It's not. kstrto*() quite strict about the input, this one is actually relaxed
variant, so I wouldn't mix these two groups.

> Also I would use int as the return parameter, see below.

...

TBH, I am skeptical about this approach. My main objection is max_chars
parameter. If we want to limit the input strictly to the given number of
characters, we have to copy the string and then just use kstrto*() in a normal
way. The whole idea of that parameter is to be able to parse the fractional
part of the float number as 'iiiii.fffff', where 'i' is for integer part, and
'f' for the fractional. Since we have *endp, we may simply check that.

In case if we want to parse only, say, 6 digits and input is longer there are
a few options (in my personal preferences, the first is the better):
- consider the input invalid
- parse it as is up to the maximum and then do ceil() or floor() on top of that
- copy only necessary amount of the (sub)string and parse that.

The problem with precision is that we need to also consider floor() or ceil()
and I don't think this should be burden of the library as it's individual
preference of each of the callers (users). At least for the starter, we will
see if it's only one approach is used, we may incorporate it into the library
code.

The easiest way out is to just consider the input invalid if it overflows the
given type (s32 or s64).

But we need to have an agreement what will be the representation of the
fixed-width float numbers in the kernel? Currently IIO uses
	struct float // name is crafted for simplicity
	{
		int integer;
		int fraction;
	}

This parser wants AFAIU to have at the end of the day something like

	struct float
	{
		s64 integer;
		s64 fraction;
	}

but also wants to have the fraction part be limited in some cases to s32
or so:

	struct float
	{
		s64 integer;
		s32 fraction; // precision may be lost if input is longer
	}

Maybe we want to have kstrtof32() and kstrtof64() for these two cases?

With that we will always consider the fraction part as 32- or 64-bit,
imply floor() on the fraction for the sake of simplicity and require
it to be NUL-terminated with possible trailing '\n'.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[Rodrigo Alencar]

On 26/03/27 09:45AM, Petr Mladek wrote:
> On Fri 2026-03-20 16:27:27, Rodrigo Alencar via B4 Relay wrote:
> > From: Rodrigo Alencar <rodrigo.alencar@analog.com>
> > 
> > Expose simple_strntoull(), by addressing its FIXME, i.e. its prototype is
> > slightly changed so that -ERANGE or -EINVAL can be evaluated by the user.
> > Flow of the function is not changed and error value is returned in the
> > end. Unsafe internal wrapper is created to reduce amount of changes.
> > 
> > --- a/include/linux/kstrtox.h
> > +++ b/include/linux/kstrtox.h
> > @@ -148,4 +148,8 @@ extern long simple_strtol(const char *,char **,unsigned int);
> >  extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
> >  extern long long simple_strtoll(const char *,char **,unsigned int);
> >  
> > +extern ssize_t __must_check simple_strntoull(const char *startp, const char **endp,
> > +					     unsigned int base, size_t max_chars,
> > +					     unsigned long long *res);
> 
> Sigh, naming is hard. I personally find it a bit confusing that the
> name is too similar to the unsafe API.
> 
> IMHO, the semantic of the new API is closer to kstrtoull().
> It just limits the size, so I would call it kstrntoull().
> 
> Also I would use int as the return parameter, see below.

Thanks for look into this one.

kstrntoull() was what I used in v8:
https://lore.kernel.org/r/20260303-adf41513-iio-driver-v8-0-8dd2417cc465@analog.com

There was a discussion around the naming:
https://lore.kernel.org/all/4mtdzxfj656sjr66npabfvrr7yd7q26l2unhsihjtniz4ossfj@g3qnzonoary6/

please suggest how the function prototype should look like.

...

> > +/* unsafe_strntoull ignores simple_strntoull() return value and endp const qualifier */
> > +inline
> > +static unsigned long long unsafe_strntoull(const char *startp, char **endp,
> > +					   unsigned int base, size_t max_chars)
> > +{
> > +	unsigned long long result;
> > +	const char *cp;
> > +
> > +#pragma GCC diagnostic push
> > +#pragma GCC diagnostic ignored "-Wunused-result"
> > +	simple_strntoull(startp, &cp, base, max_chars, &result);
> > +#pragma GCC diagnostic pop
> > +
> >  	if (endp)
> >  		*endp = (char *)cp;
> 
> IMHO, we do not need local "cp". We could simply pass the endp
> to the new simple_strntoull. Or do I miss anything?

Basically the unsafe version drops the const qualifier and compiler
complains that pointer types do not match. Maybe an extra warning can
be suppressed there.

-- 
Kind regards,

Rodrigo Alencar

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[Rodrigo Alencar]

On 26/03/27 11:17AM, Andy Shevchenko wrote:
> On Fri, Mar 27, 2026 at 09:45:17AM +0100, Petr Mladek wrote:
> > On Fri 2026-03-20 16:27:27, Rodrigo Alencar via B4 Relay wrote:
> 
> ...
> 
> > > +extern ssize_t __must_check simple_strntoull(const char *startp, const char **endp,
> > > +					     unsigned int base, size_t max_chars,
> > > +					     unsigned long long *res);
> > 
> > Sigh, naming is hard. I personally find it a bit confusing that the
> > name is too similar to the unsafe API.
> > 
> > IMHO, the semantic of the new API is closer to kstrtoull().
> > It just limits the size, so I would call it kstrntoull().
> 
> It's not. kstrto*() quite strict about the input, this one is actually relaxed
> variant, so I wouldn't mix these two groups.
> 
> > Also I would use int as the return parameter, see below.
> 
> ...
> 
> TBH, I am skeptical about this approach. My main objection is max_chars
> parameter. If we want to limit the input strictly to the given number of
> characters, we have to copy the string and then just use kstrto*() in a normal
> way. The whole idea of that parameter is to be able to parse the fractional
> part of the float number as 'iiiii.fffff', where 'i' is for integer part, and
> 'f' for the fractional. Since we have *endp, we may simply check that.

A max_chars would not be only useful for that. It can prevent out-of-bounds
reads when the input isn't NUL-terminated (like buffers, file chunks,
network packets, memory-mapped data, ....). Even if there is a NUL later in
memory, a regular strtoull() function may consume characters that are outside
the field one intends to parse.
 
> In case if we want to parse only, say, 6 digits and input is longer there are
> a few options (in my personal preferences, the first is the better):
> - consider the input invalid
> - parse it as is up to the maximum and then do ceil() or floor() on top of that
> - copy only necessary amount of the (sub)string and parse that.

Yes, my use case is the fixed point parsing, but I suppose we are implementing
things here for reuse. Also, the default behavior of the previous fixed point
parsing in IIO is flooring the result, which leads to the same result as
ignoring further digits.

> The problem with precision is that we need to also consider floor() or ceil()
> and I don't think this should be burden of the library as it's individual
> preference of each of the callers (users). At least for the starter, we will
> see if it's only one approach is used, we may incorporate it into the library
> code.
> 
> The easiest way out is to just consider the input invalid if it overflows the
> given type (s32 or s64).
> 
> But we need to have an agreement what will be the representation of the
> fixed-width float numbers in the kernel? Currently IIO uses
> 	struct float // name is crafted for simplicity
> 	{
> 		int integer;
> 		int fraction;
> 	}

Yes, but to represent things like that, an assumption is made to the precision that
"fraction" carries.

> 
> This parser wants AFAIU to have at the end of the day something like
> 
> 	struct float
> 	{
> 		s64 integer;
> 		s64 fraction;
> 	}
> 
> but also wants to have the fraction part be limited in some cases to s32
> or so:
> 
> 	struct float
> 	{
> 		s64 integer;
> 		s32 fraction; // precision may be lost if input is longer
> 	}
> 
> Maybe we want to have kstrtof32() and kstrtof64() for these two cases?
> 
> With that we will always consider the fraction part as 32- or 64-bit,
> imply floor() on the fraction for the sake of simplicity and require
> it to be NUL-terminated with possible trailing '\n'.

I think this is a good idea, but calling it float or fixed point itself
is a bit confusing as float often refers to the IEEE 754 standard and
fixed point types is often expressed in Q-format.

-- 
Kind regards,

Rodrigo Alencar

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[Andy Shevchenko]

On Fri, Mar 27, 2026 at 10:11:56AM +0000, Rodrigo Alencar wrote:
> On 26/03/27 11:17AM, Andy Shevchenko wrote:
> > On Fri, Mar 27, 2026 at 09:45:17AM +0100, Petr Mladek wrote:
> > > On Fri 2026-03-20 16:27:27, Rodrigo Alencar via B4 Relay wrote:

...

> > > > +extern ssize_t __must_check simple_strntoull(const char *startp, const char **endp,
> > > > +					     unsigned int base, size_t max_chars,
> > > > +					     unsigned long long *res);
> > > 
> > > Sigh, naming is hard. I personally find it a bit confusing that the
> > > name is too similar to the unsafe API.
> > > 
> > > IMHO, the semantic of the new API is closer to kstrtoull().
> > > It just limits the size, so I would call it kstrntoull().
> > 
> > It's not. kstrto*() quite strict about the input, this one is actually relaxed
> > variant, so I wouldn't mix these two groups.
> > 
> > > Also I would use int as the return parameter, see below.

...

> > TBH, I am skeptical about this approach. My main objection is max_chars
> > parameter. If we want to limit the input strictly to the given number of
> > characters, we have to copy the string and then just use kstrto*() in a normal
> > way. The whole idea of that parameter is to be able to parse the fractional
> > part of the float number as 'iiiii.fffff', where 'i' is for integer part, and
> > 'f' for the fractional. Since we have *endp, we may simply check that.
> 
> A max_chars would not be only useful for that. It can prevent out-of-bounds
> reads when the input isn't NUL-terminated (like buffers, file chunks,
> network packets, memory-mapped data, ....). Even if there is a NUL later in
> memory, a regular strtoull() function may consume characters that are outside
> the field one intends to parse.

Okay, but is it the current case or just an attempt to solve the problem that
doesn't exist (yet)?

> > In case if we want to parse only, say, 6 digits and input is longer there are
> > a few options (in my personal preferences, the first is the better):
> > - consider the input invalid
> > - parse it as is up to the maximum and then do ceil() or floor() on top of that
> > - copy only necessary amount of the (sub)string and parse that.
> 
> Yes, my use case is the fixed point parsing, but I suppose we are implementing
> things here for reuse.

Yes, I'm full for reuse, but I want to have it balanced between complexity,
existing use cases and possible reuse in the future.

> Also, the default behavior of the previous fixed point
> parsing in IIO is flooring the result, which leads to the same result as
> ignoring further digits.

Correct, I also lean to implying floor() (as you can read below).

> > The problem with precision is that we need to also consider floor() or ceil()
> > and I don't think this should be burden of the library as it's individual
> > preference of each of the callers (users). At least for the starter, we will
> > see if it's only one approach is used, we may incorporate it into the library
> > code.
> > 
> > The easiest way out is to just consider the input invalid if it overflows the
> > given type (s32 or s64).
> > 
> > But we need to have an agreement what will be the representation of the
> > fixed-width float numbers in the kernel? Currently IIO uses
> > 	struct float // name is crafted for simplicity
> > 	{
> > 		int integer;
> > 		int fraction;
> > 	}
> 
> Yes, but to represent things like that, an assumption is made to the precision that
> "fraction" carries.

Correct.

> > This parser wants AFAIU to have at the end of the day something like
> > 
> > 	struct float
> > 	{
> > 		s64 integer;
> > 		s64 fraction;
> > 	}
> > 
> > but also wants to have the fraction part be limited in some cases to s32
> > or so:
> > 
> > 	struct float
> > 	{
> > 		s64 integer;
> > 		s32 fraction; // precision may be lost if input is longer
> > 	}
> > 
> > Maybe we want to have kstrtof32() and kstrtof64() for these two cases?
> > 
> > With that we will always consider the fraction part as 32- or 64-bit,
> > imply floor() on the fraction for the sake of simplicity and require
> > it to be NUL-terminated with possible trailing '\n'.
> 
> I think this is a good idea, but calling it float or fixed point itself
> is a bit confusing as float often refers to the IEEE 754 standard and
> fixed point types is often expressed in Q-format.

Yeah... I am lack of better naming.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[David Laight]

On Fri, 27 Mar 2026 11:17:16 +0200
Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Fri, Mar 27, 2026 at 09:45:17AM +0100, Petr Mladek wrote:
> > On Fri 2026-03-20 16:27:27, Rodrigo Alencar via B4 Relay wrote:  
> 
> ...
> 
> > > +extern ssize_t __must_check simple_strntoull(const char *startp, const char **endp,
> > > +					     unsigned int base, size_t max_chars,
> > > +					     unsigned long long *res);  
> > 
> > Sigh, naming is hard. I personally find it a bit confusing that the
> > name is too similar to the unsafe API.
> > 
> > IMHO, the semantic of the new API is closer to kstrtoull().
> > It just limits the size, so I would call it kstrntoull().  
> 
> It's not. kstrto*() quite strict about the input, this one is actually relaxed
> variant, so I wouldn't mix these two groups.
> 
> > Also I would use int as the return parameter, see below.  
> 
> ...
> 
> TBH, I am skeptical about this approach. My main objection is max_chars
> parameter. If we want to limit the input strictly to the given number of
> characters, we have to copy the string and then just use kstrto*() in a normal
> way. The whole idea of that parameter is to be able to parse the fractional
> part of the float number as 'iiiii.fffff', where 'i' is for integer part, and
> 'f' for the fractional. Since we have *endp, we may simply check that.
> 
> In case if we want to parse only, say, 6 digits and input is longer there are
> a few options (in my personal preferences, the first is the better):
> - consider the input invalid
> - parse it as is up to the maximum and then do ceil() or floor() on top of that
> - copy only necessary amount of the (sub)string and parse that.

Isn't there a bigger problem?
If you want a max of 6 digits you need to correctly parse 3.1 3.159265
3.159256358979 3.0001 3.000159 3.00015926535 3.000100 (etc).
That seems to always require checking the length and then multiply/divide
by 10.

Then there is 'round to even' which rounds these two in opposite directions:
   4.500000000000000000000000000000000000000000000000000
   4.500000000000000000000000000000000000000000000000001

I suspect you really want a completely different function for reading
fractional parts of floating point numbers.
It isn't as though the actual digit conversion is hard.

> 
> The problem with precision is that we need to also consider floor() or ceil()
> and I don't think this should be burden of the library as it's individual
> preference of each of the callers (users). At least for the starter, we will
> see if it's only one approach is used, we may incorporate it into the library
> code.
> 
> The easiest way out is to just consider the input invalid if it overflows the
> given type (s32 or s64).
> 
> But we need to have an agreement what will be the representation of the
> fixed-width float numbers in the kernel? Currently IIO uses
> 	struct float // name is crafted for simplicity
> 	{
> 		int integer;
> 		int fraction;
> 	}
> 
> This parser wants AFAIU to have at the end of the day something like
> 
> 	struct float
> 	{
> 		s64 integer;
> 		s64 fraction;
> 	}
> 
> but also wants to have the fraction part be limited in some cases to s32
> or so:
> 
> 	struct float
> 	{
> 		s64 integer;
> 		s32 fraction; // precision may be lost if input is longer
> 	}

Are those 'fraction' counts of (say) 10^-6 (like times in seconds+usecs)
or true binary values where the value could be treated as a u64 (or u128)
for addition and subtraction.
So parse the latter you don't need to know the length
(and it can be converted the to former by multiplying by 10^6).

	David

> 
> Maybe we want to have kstrtof32() and kstrtof64() for these two cases?
> 
> With that we will always consider the fraction part as 32- or 64-bit,
> imply floor() on the fraction for the sake of simplicity and require
> it to be NUL-terminated with possible trailing '\n'.
> 

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[Andy Shevchenko]

On Fri, Mar 27, 2026 at 10:44:40AM +0000, David Laight wrote:
> On Fri, 27 Mar 2026 11:17:16 +0200
> Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

...

> > TBH, I am skeptical about this approach. My main objection is max_chars
> > parameter. If we want to limit the input strictly to the given number of
> > characters, we have to copy the string and then just use kstrto*() in a normal
> > way. The whole idea of that parameter is to be able to parse the fractional
> > part of the float number as 'iiiii.fffff', where 'i' is for integer part, and
> > 'f' for the fractional. Since we have *endp, we may simply check that.
> > 
> > In case if we want to parse only, say, 6 digits and input is longer there are
> > a few options (in my personal preferences, the first is the better):
> > - consider the input invalid
> > - parse it as is up to the maximum and then do ceil() or floor() on top of that
> > - copy only necessary amount of the (sub)string and parse that.
> 
> Isn't there a bigger problem?
> If you want a max of 6 digits you need to correctly parse 3.1 3.159265
> 3.159256358979 3.0001 3.000159 3.00015926535 3.000100 (etc).
> That seems to always require checking the length and then multiply/divide
> by 10.

Yep.

> Then there is 'round to even' which rounds these two in opposite directions:
>    4.500000000000000000000000000000000000000000000000000
>    4.500000000000000000000000000000000000000000000000001

These are wrong inputs and if we want to have them cut, it will be just a cut.
(Yeah, which will have different result for negative numbers.)

> I suspect you really want a completely different function for reading
> fractional parts of floating point numbers.
> It isn't as though the actual digit conversion is hard.
> 
> > The problem with precision is that we need to also consider floor() or ceil()
> > and I don't think this should be burden of the library as it's individual
> > preference of each of the callers (users). At least for the starter, we will
> > see if it's only one approach is used, we may incorporate it into the library
> > code.
> > 
> > The easiest way out is to just consider the input invalid if it overflows the
> > given type (s32 or s64).
> > 
> > But we need to have an agreement what will be the representation of the
> > fixed-width float numbers in the kernel? Currently IIO uses
> > 	struct float // name is crafted for simplicity
> > 	{
> > 		int integer;
> > 		int fraction;
> > 	}
> > 
> > This parser wants AFAIU to have at the end of the day something like
> > 
> > 	struct float
> > 	{
> > 		s64 integer;
> > 		s64 fraction;
> > 	}
> > 
> > but also wants to have the fraction part be limited in some cases to s32
> > or so:
> > 
> > 	struct float
> > 	{
> > 		s64 integer;
> > 		s32 fraction; // precision may be lost if input is longer
> > 	}
> 
> Are those 'fraction' counts of (say) 10^-6 (like times in seconds+usecs)
> or true binary values where the value could be treated as a u64 (or u128)
> for addition and subtraction.

It depends. IIO has scale on top of that, so the fraction part can be 10⁻³,
10⁻⁶, 10⁻⁹. I don't remember by heart if the ABI requires all digits to be
placed, I think we don't require that.

> So parse the latter you don't need to know the length
> (and it can be converted the to former by multiplying by 10^6).
> 
> > Maybe we want to have kstrtof32() and kstrtof64() for these two cases?
> > 
> > With that we will always consider the fraction part as 32- or 64-bit,
> > imply floor() on the fraction for the sake of simplicity and require
> > it to be NUL-terminated with possible trailing '\n'.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[David Laight]

On Fri, 27 Mar 2026 12:57:56 +0200
Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Fri, Mar 27, 2026 at 10:44:40AM +0000, David Laight wrote:
,,,
> > > but also wants to have the fraction part be limited in some cases to s32
> > > or so:
> > > 
> > > 	struct float
> > > 	{
> > > 		s64 integer;
> > > 		s32 fraction; // precision may be lost if input is longer
> > > 	}  
> > 
> > Are those 'fraction' counts of (say) 10^-6 (like times in seconds+usecs)
> > or true binary values where the value could be treated as a u64 (or u128)
> > for addition and subtraction.  
> 
> It depends. IIO has scale on top of that, so the fraction part can be 10⁻³,
> 10⁻⁶, 10⁻⁹. I don't remember by heart if the ABI requires all digits to be
> placed, I think we don't require that.

Seems like you want this function (untested):
u64 strtofrac(const char *buf, const char **end, unsigned int len)
{
	u64 val = 0;
	unsigned int digit;

	while (len--) {
		digit = *buf - '0';
		if (digit <= 9) {
			buf++;
			val += digit;
		}
		val *= 10;
	}
	while (*buf - '0' <= 9u)
		buf++;
	*end = buf;
	return val;
}

	David

Re: [PATCH v9 2/9] lib: vsprintf: export simple_strntoull() in a safe prototype

[Rodrigo Alencar]

On 26/03/27 12:21PM, Andy Shevchenko wrote:
> On Fri, Mar 27, 2026 at 10:11:56AM +0000, Rodrigo Alencar wrote:
> > On 26/03/27 11:17AM, Andy Shevchenko wrote:
> > > On Fri, Mar 27, 2026 at 09:45:17AM +0100, Petr Mladek wrote:
> > > > On Fri 2026-03-20 16:27:27, Rodrigo Alencar via B4 Relay wrote:
> 
> ...
> 
> > > > > +extern ssize_t __must_check simple_strntoull(const char *startp, const char **endp,
> > > > > +					     unsigned int base, size_t max_chars,
> > > > > +					     unsigned long long *res);
> > > > 
> > > > Sigh, naming is hard. I personally find it a bit confusing that the
> > > > name is too similar to the unsafe API.
> > > > 
> > > > IMHO, the semantic of the new API is closer to kstrtoull().
> > > > It just limits the size, so I would call it kstrntoull().
> > > 
> > > It's not. kstrto*() quite strict about the input, this one is actually relaxed
> > > variant, so I wouldn't mix these two groups.
> > > 
> > > > Also I would use int as the return parameter, see below.
> 
> ...
> 
> > > TBH, I am skeptical about this approach. My main objection is max_chars
> > > parameter. If we want to limit the input strictly to the given number of
> > > characters, we have to copy the string and then just use kstrto*() in a normal
> > > way. The whole idea of that parameter is to be able to parse the fractional
> > > part of the float number as 'iiiii.fffff', where 'i' is for integer part, and
> > > 'f' for the fractional. Since we have *endp, we may simply check that.
> > 
> > A max_chars would not be only useful for that. It can prevent out-of-bounds
> > reads when the input isn't NUL-terminated (like buffers, file chunks,
> > network packets, memory-mapped data, ....). Even if there is a NUL later in
> > memory, a regular strtoull() function may consume characters that are outside
> > the field one intends to parse.
> 
> Okay, but is it the current case or just an attempt to solve the problem that
> doesn't exist (yet)?

The current case can be seen as such. Copying the string and use regular ksrto*()
requires an unecessary scan of string from the user side, which is something that
_parse_integer_limit() already does, mostly because it checks for digits and stops
at any non-digit character. In the IIO case, we also want control over the consumed
characters because there are weird terminations like "dB", so having an implementation
like this ends up with a cleaner sequence of steps. 

> > > In case if we want to parse only, say, 6 digits and input is longer there are
> > > a few options (in my personal preferences, the first is the better):
> > > - consider the input invalid
> > > - parse it as is up to the maximum and then do ceil() or floor() on top of that
> > > - copy only necessary amount of the (sub)string and parse that.
> > 
> > Yes, my use case is the fixed point parsing, but I suppose we are implementing
> > things here for reuse.
> 
> Yes, I'm full for reuse, but I want to have it balanced between complexity,
> existing use cases and possible reuse in the future.

Not seeing complexity here as in this case I am just exposing something
that already exists! No need for a completely different implementation.
I just want to get an agreement on the naming and interface prototype.

Bringing back the discussion again just because I suppose Petr havent even
seen the v8 of this patch series. If kstrtox.h is the right place for this,
kstrntoull() sounds like ideal. Specially because simple_strto*() is already
labeled as unsafe and kstrnto*() != kstrto*().

> > Also, the default behavior of the previous fixed point
> > parsing in IIO is flooring the result, which leads to the same result as
> > ignoring further digits.
> 
> Correct, I also lean to implying floor() (as you can read below).
> 
> > > The problem with precision is that we need to also consider floor() or ceil()
> > > and I don't think this should be burden of the library as it's individual
> > > preference of each of the callers (users). At least for the starter, we will
> > > see if it's only one approach is used, we may incorporate it into the library
> > > code.
> > > 
> > > The easiest way out is to just consider the input invalid if it overflows the
> > > given type (s32 or s64).
> > > 
> > > But we need to have an agreement what will be the representation of the
> > > fixed-width float numbers in the kernel? Currently IIO uses
> > > 	struct float // name is crafted for simplicity
> > > 	{
> > > 		int integer;
> > > 		int fraction;
> > > 	}
> > 
> > Yes, but to represent things like that, an assumption is made to the precision that
> > "fraction" carries.
> 
> Correct.
> 
> > > This parser wants AFAIU to have at the end of the day something like
> > > 
> > > 	struct float
> > > 	{
> > > 		s64 integer;
> > > 		s64 fraction;
> > > 	}
> > > 
> > > but also wants to have the fraction part be limited in some cases to s32
> > > or so:
> > > 
> > > 	struct float
> > > 	{
> > > 		s64 integer;
> > > 		s32 fraction; // precision may be lost if input is longer
> > > 	}
> > > 
> > > Maybe we want to have kstrtof32() and kstrtof64() for these two cases?
> > > 
> > > With that we will always consider the fraction part as 32- or 64-bit,
> > > imply floor() on the fraction for the sake of simplicity and require
> > > it to be NUL-terminated with possible trailing '\n'.
> > 
> > I think this is a good idea, but calling it float or fixed point itself
> > is a bit confusing as float often refers to the IEEE 754 standard and
> > fixed point types is often expressed in Q-format.
> 
> Yeah... I am lack of better naming.

decimals is the name, but they are often represented as:

	DECIMAL = INT * 10^X + FRAC

in a single 64-bit number, which would be fine for my end use case.
However IIO decimal fixed point parsing is out there for quite some time a
lot of drivers use that. The interface often relies on breaking parsed values
into an integer array (for standard attributes int val and int val2 are expected).

-- 
Kind regards,

Rodrigo Alencar