Add clk provider feature for the adf4377.

Even though the driver was sent as an IIO driver in most cases the
device is actually seen as a clock provider.

This patch aims to cover actual usecases requested by users in order to
completely control the output frequencies from userspace.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
Changes in v3:
 - Replace .is_enabled clock operation with .is_prepared
 - Use modern devm_clk_hw_register() instead of devm_clk_register()
 - Switch to clk_parent_data with fw_name instead of parent_names array
 - Use devm_of_clk_add_hw_provider() with of_clk_hw_simple_get for modern DT integration
 - Fix indentation alignment in adf4377_clk_recalc_rate function parameter
 - Remove manual clock provider cleanup by using devm_* variants
 drivers/iio/frequency/adf4377.c | 119 +++++++++++++++++++++++++++++++-
 1 file changed, 117 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/frequency/adf4377.c b/drivers/iio/frequency/adf4377.c
index 08833b7035e4..045747351ed7 100644
--- a/drivers/iio/frequency/adf4377.c
+++ b/drivers/iio/frequency/adf4377.c
@@ -8,6 +8,7 @@
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/clkdev.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -435,9 +436,14 @@ struct adf4377_state {
 	struct gpio_desc	*gpio_ce;
 	struct gpio_desc	*gpio_enclk1;
 	struct gpio_desc	*gpio_enclk2;
+	struct clk		*clk;
+	struct clk		*clkout;
+	struct clk_hw		hw;
 	u8			buf[2] __aligned(IIO_DMA_MINALIGN);
 };
 
+#define to_adf4377_state(h)	container_of(h, struct adf4377_state, hw)
+
 static const char * const adf4377_muxout_modes[] = {
 	[ADF4377_MUXOUT_HIGH_Z] = "high_z",
 	[ADF4377_MUXOUT_LKDET] = "lock_detect",
@@ -929,6 +935,108 @@ static int adf4377_freq_change(struct notifier_block *nb, unsigned long action,
 	return NOTIFY_OK;
 }
 
+static unsigned long adf4377_clk_recalc_rate(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	struct adf4377_state *st = to_adf4377_state(hw);
+	u64 freq;
+	int ret;
+
+	ret = adf4377_get_freq(st, &freq);
+	if (ret)
+		return 0;
+
+	return freq;
+}
+
+static int adf4377_clk_set_rate(struct clk_hw *hw,
+				unsigned long rate,
+				unsigned long parent_rate)
+{
+	struct adf4377_state *st = to_adf4377_state(hw);
+
+	return adf4377_set_freq(st, rate);
+}
+
+static int adf4377_clk_prepare(struct clk_hw *hw)
+{
+	struct adf4377_state *st = to_adf4377_state(hw);
+
+	return regmap_update_bits(st->regmap, 0x1a, ADF4377_001A_PD_CLKOUT1_MSK |
+				  ADF4377_001A_PD_CLKOUT2_MSK,
+				  FIELD_PREP(ADF4377_001A_PD_CLKOUT1_MSK, 0) |
+				  FIELD_PREP(ADF4377_001A_PD_CLKOUT2_MSK, 0));
+}
+
+static void adf4377_clk_unprepare(struct clk_hw *hw)
+{
+	struct adf4377_state *st = to_adf4377_state(hw);
+
+	regmap_update_bits(st->regmap, 0x1a, ADF4377_001A_PD_CLKOUT1_MSK |
+			   ADF4377_001A_PD_CLKOUT2_MSK,
+			   FIELD_PREP(ADF4377_001A_PD_CLKOUT1_MSK, 1) |
+			   FIELD_PREP(ADF4377_001A_PD_CLKOUT2_MSK, 1));
+}
+
+static int adf4377_clk_is_prepared(struct clk_hw *hw)
+{
+	struct adf4377_state *st = to_adf4377_state(hw);
+	unsigned int readval;
+	int ret;
+
+	ret = regmap_read(st->regmap, 0x1a, &readval);
+	if (ret)
+		return ret;
+
+	return !(readval & (ADF4377_001A_PD_CLKOUT1_MSK | ADF4377_001A_PD_CLKOUT2_MSK));
+}
+
+static const struct clk_ops adf4377_clk_ops = {
+	.recalc_rate = adf4377_clk_recalc_rate,
+	.set_rate = adf4377_clk_set_rate,
+	.prepare = adf4377_clk_prepare,
+	.unprepare = adf4377_clk_unprepare,
+	.is_prepared = adf4377_clk_is_prepared,
+};
+
+static int adf4377_clk_register(struct adf4377_state *st)
+{
+	struct spi_device *spi = st->spi;
+	struct clk_init_data init;
+	struct clk_parent_data parent_data;
+	int ret;
+
+	if (!device_property_present(&spi->dev, "#clock-cells"))
+		return 0;
+
+	if (device_property_read_string(&spi->dev, "clock-output-names", &init.name)) {
+		init.name = devm_kasprintf(&spi->dev, GFP_KERNEL, "%s-clk",
+					   fwnode_get_name(dev_fwnode(&spi->dev)));
+		if (!init.name)
+			return -ENOMEM;
+	}
+
+	parent_data.fw_name = "ref_in";
+
+	init.ops = &adf4377_clk_ops;
+	init.parent_data = &parent_data;
+	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_PARENT;
+
+	st->hw.init = &init;
+	ret = devm_clk_hw_register(&spi->dev, &st->hw);
+	if (ret)
+		return ret;
+
+	ret = devm_of_clk_add_hw_provider(&spi->dev, of_clk_hw_simple_get, &st->hw);
+	if (ret)
+		return ret;
+
+	st->clkout = st->hw.clk;
+
+	return 0;
+}
+
 static const struct adf4377_chip_info adf4377_chip_info = {
 	.name = "adf4377",
 	.has_gpio_enclk2 = true,
@@ -958,8 +1066,6 @@ static int adf4377_probe(struct spi_device *spi)
 
 	indio_dev->info = &adf4377_info;
 	indio_dev->name = "adf4377";
-	indio_dev->channels = adf4377_channels;
-	indio_dev->num_channels = ARRAY_SIZE(adf4377_channels);
 
 	st->regmap = regmap;
 	st->spi = spi;
@@ -979,6 +1085,15 @@ static int adf4377_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
+	ret = adf4377_clk_register(st);
+	if (ret)
+		return ret;
+
+	if (!st->clkout) {
+		indio_dev->channels = adf4377_channels;
+		indio_dev->num_channels = ARRAY_SIZE(adf4377_channels);
+	}
+
 	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
-- 
2.43.0

On Tue, Nov 25, 2025 at 5:48 PM Antoniu Miclaus
<antoniu.miclaus@analog.com> wrote:
>
> Add clk provider feature for the adf4377.
>
> Even though the driver was sent as an IIO driver in most cases the
> device is actually seen as a clock provider.
>
> This patch aims to cover actual usecases requested by users in order to
> completely control the output frequencies from userspace.

...

> +static int adf4377_clk_register(struct adf4377_state *st)
> +{
> +       struct spi_device *spi = st->spi;
> +       struct clk_init_data init;
> +       struct clk_parent_data parent_data;
> +       int ret;
> +
> +       if (!device_property_present(&spi->dev, "#clock-cells"))
> +               return 0;
> +
> +       if (device_property_read_string(&spi->dev, "clock-output-names", &init.name)) {

I would rather split this to two

  ret = device_property_read_string(...);
  if (ret) {
    ...
  }

which makes the intention more explicit, otherwise it's not clear what
the return values are and what you do with them (since I know it's
int, the rule of thumb to assign to int variable and check it, for
boolean it's fine to do if (boolean_fn(...)) in the code).

> +               init.name = devm_kasprintf(&spi->dev, GFP_KERNEL, "%s-clk",
> +                                          fwnode_get_name(dev_fwnode(&spi->dev)));

%pfw / %pfwP

> +               if (!init.name)
> +                       return -ENOMEM;
> +       }
> +
> +       parent_data.fw_name = "ref_in";
> +
> +       init.ops = &adf4377_clk_ops;
> +       init.parent_data = &parent_data;
> +       init.num_parents = 1;
> +       init.flags = CLK_SET_RATE_PARENT;
> +
> +       st->hw.init = &init;
> +       ret = devm_clk_hw_register(&spi->dev, &st->hw);
> +       if (ret)
> +               return ret;
> +
> +       ret = devm_of_clk_add_hw_provider(&spi->dev, of_clk_hw_simple_get, &st->hw);
> +       if (ret)
> +               return ret;
> +
> +       st->clkout = st->hw.clk;
> +
> +       return 0;
> +}

Otherwise LGTM.

-- 
With Best Regards,
Andy Shevchenko

On Tue, Nov 25, 2025 at 6:21 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Tue, Nov 25, 2025 at 5:48 PM Antoniu Miclaus
> <antoniu.miclaus@analog.com> wrote:

...

> > +static int adf4377_clk_register(struct adf4377_state *st)
> > +{
> > +       struct spi_device *spi = st->spi;

Also consider to have

  struct device *dev = &spi->dev;

here, and use it below to make less LoCs and better to read code.

> > +       struct clk_init_data init;
> > +       struct clk_parent_data parent_data;
> > +       int ret;
> > +
> > +       if (!device_property_present(&spi->dev, "#clock-cells"))
> > +               return 0;
> > +
> > +       if (device_property_read_string(&spi->dev, "clock-output-names", &init.name)) {
>
> I would rather split this to two
>
>   ret = device_property_read_string(...);
>   if (ret) {
>     ...
>   }
>
> which makes the intention more explicit, otherwise it's not clear what
> the return values are and what you do with them (since I know it's
> int, the rule of thumb to assign to int variable and check it, for
> boolean it's fine to do if (boolean_fn(...)) in the code).
>
> > +               init.name = devm_kasprintf(&spi->dev, GFP_KERNEL, "%s-clk",
> > +                                          fwnode_get_name(dev_fwnode(&spi->dev)));
>
> %pfw / %pfwP
>
> > +               if (!init.name)
> > +                       return -ENOMEM;
> > +       }
> > +
> > +       parent_data.fw_name = "ref_in";
> > +
> > +       init.ops = &adf4377_clk_ops;
> > +       init.parent_data = &parent_data;
> > +       init.num_parents = 1;
> > +       init.flags = CLK_SET_RATE_PARENT;
> > +
> > +       st->hw.init = &init;
> > +       ret = devm_clk_hw_register(&spi->dev, &st->hw);
> > +       if (ret)
> > +               return ret;
> > +
> > +       ret = devm_of_clk_add_hw_provider(&spi->dev, of_clk_hw_simple_get, &st->hw);
> > +       if (ret)
> > +               return ret;
> > +
> > +       st->clkout = st->hw.clk;
> > +
> > +       return 0;
> > +}
>
> Otherwise LGTM.
>
> --
> With Best Regards,
> Andy Shevchenko



-- 
With Best Regards,
Andy Shevchenko