[PATCH v5 0/3] ADF4371 refin mode and doubler support

[PATCH v5 0/3] ADF4371 refin mode and doubler support

[Antoniu Miclaus]

Add support for selecting between single-ended and differential
reference input. By default the single-ended input is enabled.

Input frequency boundaries are change based on the mode selected
(single-ended/differential).

Add support for the reference doubler. This feature is enabled
automatically to improve noise performance if the input frequency
is within the accepted range.

Antoniu Miclaus (3):
  dt-bindings: iio: adf4371: add refin mode
  iio: frequency: adf4371: add refin mode
  iio: frequency: adf4371: add ref doubler

 .../bindings/iio/frequency/adf4371.yaml       |  5 ++-
 drivers/iio/frequency/adf4371.c               | 44 +++++++++++++++++--
 2 files changed, 43 insertions(+), 6 deletions(-)

-- 
2.48.1

[PATCH v5 1/3] dt-bindings: iio: adf4371: add refin mode

[Antoniu Miclaus]

Add support for selecting between single-ended and differential
reference input.

Input frequency boundaries are change based on the mode selected
(single-ended/differential).

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
changes in v5:
 - drop default description/option.
 Documentation/devicetree/bindings/iio/frequency/adf4371.yaml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/frequency/adf4371.yaml b/Documentation/devicetree/bindings/iio/frequency/adf4371.yaml
index 1cb2adaf66f9..53d607441612 100644
--- a/Documentation/devicetree/bindings/iio/frequency/adf4371.yaml
+++ b/Documentation/devicetree/bindings/iio/frequency/adf4371.yaml
@@ -30,8 +30,9 @@ properties:
 
   clock-names:
     description:
-      Must be "clkin"
-    maxItems: 1
+      Must be "clkin" if the input reference is single ended or "clkin-diff"
+      if the input reference is differential.
+    enum: [clkin, clkin-diff]
 
   adi,mute-till-lock-en:
     type: boolean
-- 
2.48.1

[PATCH v5 2/3] iio: frequency: adf4371: add refin mode

[Antoniu Miclaus]

Add support for single-ended/differential reference input mode.

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
no changes in v5.
 drivers/iio/frequency/adf4371.c | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/frequency/adf4371.c b/drivers/iio/frequency/adf4371.c
index b27088464826..50450e7b5464 100644
--- a/drivers/iio/frequency/adf4371.c
+++ b/drivers/iio/frequency/adf4371.c
@@ -41,6 +41,10 @@
 #define ADF4371_MOD2WORD_MSK		GENMASK(5, 0)
 #define ADF4371_MOD2WORD(x)		FIELD_PREP(ADF4371_MOD2WORD_MSK, x)
 
+/* ADF4371_REG22 */
+#define ADF4371_REFIN_MODE_MASK		BIT(6)
+#define ADF4371_REFIN_MODE(x)		FIELD_PREP(ADF4371_REFIN_MODE_MASK, x)
+
 /* ADF4371_REG24 */
 #define ADF4371_RF_DIV_SEL_MSK		GENMASK(6, 4)
 #define ADF4371_RF_DIV_SEL(x)		FIELD_PREP(ADF4371_RF_DIV_SEL_MSK, x)
@@ -69,6 +73,7 @@
 
 #define ADF4371_MAX_FREQ_PFD		250000000UL /* Hz */
 #define ADF4371_MAX_FREQ_REFIN		600000000UL /* Hz */
+#define ADF4371_MAX_FREQ_REFIN_SE	500000000UL /* Hz */
 
 /* MOD1 is a 24-bit primary modulus with fixed value of 2^25 */
 #define ADF4371_MODULUS1		33554432ULL
@@ -175,6 +180,7 @@ struct adf4371_state {
 	unsigned int mod2;
 	unsigned int rf_div_sel;
 	unsigned int ref_div_factor;
+	bool ref_diff_en;
 	u8 buf[10] __aligned(IIO_DMA_MINALIGN);
 };
 
@@ -503,6 +509,17 @@ static int adf4371_setup(struct adf4371_state *st)
 				 ADF4371_ADDR_ASC(1) | ADF4371_ADDR_ASC_R(1));
 	if (ret < 0)
 		return ret;
+
+	if ((st->ref_diff_en && st->clkin_freq > ADF4371_MAX_FREQ_REFIN) ||
+	    (!st->ref_diff_en && st->clkin_freq > ADF4371_MAX_FREQ_REFIN_SE))
+		return -EINVAL;
+
+	ret = regmap_update_bits(st->regmap,  ADF4371_REG(0x22),
+				 ADF4371_REFIN_MODE_MASK,
+				 ADF4371_REFIN_MODE(st->ref_diff_en));
+	if (ret < 0)
+		return ret;
+
 	/*
 	 * Calculate and maximize PFD frequency
 	 * fPFD = REFIN × ((1 + D)/(R × (1 + T)))
@@ -572,9 +589,16 @@ static int adf4371_probe(struct spi_device *spi)
 	indio_dev->channels = st->chip_info->channels;
 	indio_dev->num_channels = st->chip_info->num_channels;
 
+	st->ref_diff_en = false;
+
 	st->clkin = devm_clk_get_enabled(&spi->dev, "clkin");
-	if (IS_ERR(st->clkin))
-		return PTR_ERR(st->clkin);
+	if (IS_ERR(st->clkin)) {
+		st->clkin = devm_clk_get_enabled(&spi->dev, "clkin-diff");
+		if (IS_ERR(st->clkin))
+			return PTR_ERR(st->clkin);
+
+		st->ref_diff_en = true;
+	}
 
 	st->clkin_freq = clk_get_rate(st->clkin);
 
-- 
2.48.1

[PATCH v5 3/3] iio: frequency: adf4371: add ref doubler

[Antoniu Miclaus]

Add support for the reference doubler.

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
no changes in v5.
 drivers/iio/frequency/adf4371.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/frequency/adf4371.c b/drivers/iio/frequency/adf4371.c
index 50450e7b5464..a57fc24a6799 100644
--- a/drivers/iio/frequency/adf4371.c
+++ b/drivers/iio/frequency/adf4371.c
@@ -44,6 +44,8 @@
 /* ADF4371_REG22 */
 #define ADF4371_REFIN_MODE_MASK		BIT(6)
 #define ADF4371_REFIN_MODE(x)		FIELD_PREP(ADF4371_REFIN_MODE_MASK, x)
+#define ADF4371_REF_DOUB_MASK		BIT(5)
+#define ADF4371_REF_DOUB(x)		FIELD_PREP(ADF4371_REF_DOUB_MASK, x)\
 
 /* ADF4371_REG24 */
 #define ADF4371_RF_DIV_SEL_MSK		GENMASK(6, 4)
@@ -75,6 +77,9 @@
 #define ADF4371_MAX_FREQ_REFIN		600000000UL /* Hz */
 #define ADF4371_MAX_FREQ_REFIN_SE	500000000UL /* Hz */
 
+#define ADF4371_MIN_CLKIN_DOUB_FREQ	10000000ULL /* Hz */
+#define ADF4371_MAX_CLKIN_DOUB_FREQ	125000000ULL /* Hz */
+
 /* MOD1 is a 24-bit primary modulus with fixed value of 2^25 */
 #define ADF4371_MODULUS1		33554432ULL
 /* MOD2 is the programmable, 14-bit auxiliary fractional modulus */
@@ -481,7 +486,7 @@ static const struct iio_info adf4371_info = {
 static int adf4371_setup(struct adf4371_state *st)
 {
 	unsigned int synth_timeout = 2, timeout = 1, vco_alc_timeout = 1;
-	unsigned int vco_band_div, tmp;
+	unsigned int vco_band_div, tmp, ref_doubler_en = 0;
 	int ret;
 
 	/* Perform a software reset */
@@ -514,8 +519,14 @@ static int adf4371_setup(struct adf4371_state *st)
 	    (!st->ref_diff_en && st->clkin_freq > ADF4371_MAX_FREQ_REFIN_SE))
 		return -EINVAL;
 
+	if (st->clkin_freq < ADF4371_MAX_CLKIN_DOUB_FREQ &&
+	    st->clkin_freq > ADF4371_MIN_CLKIN_DOUB_FREQ)
+		ref_doubler_en = 1;
+
 	ret = regmap_update_bits(st->regmap,  ADF4371_REG(0x22),
+				 ADF4371_REF_DOUB_MASK |
 				 ADF4371_REFIN_MODE_MASK,
+				 ADF4371_REF_DOUB(ref_doubler_en) |
 				 ADF4371_REFIN_MODE(st->ref_diff_en));
 	if (ret < 0)
 		return ret;
@@ -529,7 +540,8 @@ static int adf4371_setup(struct adf4371_state *st)
 	 */
 	do {
 		st->ref_div_factor++;
-		st->fpfd = st->clkin_freq / st->ref_div_factor;
+		st->fpfd = st->clkin_freq * (1 + ref_doubler_en) /
+			   st->ref_div_factor;
 	} while (st->fpfd > ADF4371_MAX_FREQ_PFD);
 
 	/* Calculate Timeouts */
-- 
2.48.1

Re: [PATCH v5 1/3] dt-bindings: iio: adf4371: add refin mode

[Conor Dooley]

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On Mon, Jan 20, 2025 at 01:34:02PM +0200, Antoniu Miclaus wrote:
> Add support for selecting between single-ended and differential
> reference input.
> 
> Input frequency boundaries are change based on the mode selected
> (single-ended/differential).
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>

Acked-by: Conor Dooley <conor.dooley@microchip.com>

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Re: [PATCH v5 0/3] ADF4371 refin mode and doubler support

[Jonathan Cameron]

On Mon, 20 Jan 2025 13:34:01 +0200
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Add support for selecting between single-ended and differential
> reference input. By default the single-ended input is enabled.
> 
> Input frequency boundaries are change based on the mode selected
> (single-ended/differential).
> 
> Add support for the reference doubler. This feature is enabled
> automatically to improve noise performance if the input frequency
> is within the accepted range.
> 
> Antoniu Miclaus (3):
>   dt-bindings: iio: adf4371: add refin mode
>   iio: frequency: adf4371: add refin mode
>   iio: frequency: adf4371: add ref doubler
Hi Antoniu

This needs a rebase as there was some recent cleanup from Nuno of
the driver so your set doesn't apply.

Thanks,

Jonathan

> 
>  .../bindings/iio/frequency/adf4371.yaml       |  5 ++-
>  drivers/iio/frequency/adf4371.c               | 44 +++++++++++++++++--
>  2 files changed, 43 insertions(+), 6 deletions(-)
>