[PATCH v5 2/2] iio: frequency: adf4350: add clk provider

Antoniu Miclaus
2024-06-18T08:21:57Z

Add clk provider feature for the adf4350.

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 v5:
- add error handling for dt properties parse.
- drop all IIO channels if driver acts as clock provider.
drivers/iio/frequency/adf4350.c | 129 +++++++++++++++++++++++++++++++-
1 file changed, 127 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/frequency/adf4350.c b/drivers/iio/frequency/adf4350.c
index 4abf80f75ef5..d0791a21e65c 100644
--- a/drivers/iio/frequency/adf4350.c
+++ b/drivers/iio/frequency/adf4350.c
@@ -19,6 +19,7 @@
#include <linux/gpio/consumer.h>
#include <asm/div64.h>
#include <linux/clk.h>
+#include <linux/clk-provider.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -36,6 +37,9 @@ struct adf4350_state {
struct gpio_desc *lock_detect_gpiod;
struct adf4350_platform_data *pdata;
struct clk *clk;
+ struct clk *clkout;
+ const char *clk_out_name;
+ struct clk_hw hw;
unsigned long clkin;
unsigned long chspc; /* Channel Spacing */
unsigned long fpfd; /* Phase Frequency Detector */
@@ -61,6 +65,8 @@ struct adf4350_state {
__be32 val __aligned(IIO_DMA_MINALIGN);
};

+#define to_adf4350_state(_hw) container_of(_hw, struct adf4350_state, hw)
+
static struct adf4350_platform_data default_pdata = {
.channel_spacing = 10000,
.r2_user_settings = ADF4350_REG2_PD_POLARITY_POS |
@@ -381,6 +387,115 @@ static const struct iio_info adf4350_info = {
.debugfs_reg_access = &adf4350_reg_access,
};

+static void adf4350_clk_del_provider(void *data)
+{
+ struct adf4350_state *st = data;
+
+ of_clk_del_provider(st->spi->dev.of_node);
+}
+
+static unsigned long adf4350_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct adf4350_state *st = to_adf4350_state(hw);
+ unsigned long long tmp;
+
+ tmp = (u64)(st->r0_int * st->r1_mod + st->r0_fract) * st->fpfd;
+ do_div(tmp, st->r1_mod * (1 << st->r4_rf_div_sel));
+
+ return tmp;
+}
+
+static int adf4350_clk_set_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct adf4350_state *st = to_adf4350_state(hw);
+
+ if (parent_rate == 0 || parent_rate > ADF4350_MAX_FREQ_REFIN)
+ return -EINVAL;
+
+ st->clkin = parent_rate;
+
+ return adf4350_set_freq(st, rate);
+}
+
+static int adf4350_clk_prepare(struct clk_hw *hw)
+{
+ struct adf4350_state *st = to_adf4350_state(hw);
+
+ st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN;
+
+ return adf4350_sync_config(st);
+}
+
+static void adf4350_clk_unprepare(struct clk_hw *hw)
+{
+ struct adf4350_state *st = to_adf4350_state(hw);
+
+ st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
+
+ adf4350_sync_config(st);
+}
+
+static int adf4350_clk_is_enabled(struct clk_hw *hw)
+{
+ struct adf4350_state *st = to_adf4350_state(hw);
+
+ return (st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN);
+}
+
+static const struct clk_ops adf4350_clk_ops = {
+ .recalc_rate = adf4350_clk_recalc_rate,
+ .set_rate = adf4350_clk_set_rate,
+ .prepare = adf4350_clk_prepare,
+ .unprepare = adf4350_clk_unprepare,
+ .is_enabled = adf4350_clk_is_enabled,
+};
+
+static int adf4350_clk_register(struct adf4350_state *st)
+{
+ struct spi_device *spi = st->spi;
+ struct clk_init_data init;
+ struct clk *clk;
+ const char *parent_name;
+ int ret;
+
+ if (!device_property_present(&spi->dev, "#clock-cells"))
+ return 0;
+
+ init.name = devm_kasprintf(&spi->dev, GFP_KERNEL, "%s-clk",
+ fwnode_get_name(dev_fwnode(&spi->dev)));
+ if (!init.name)
+ return -ENOMEM;
+
+ if (device_property_read_string(&spi->dev, "clock-output-names",
+ &init.name))
+ init.name = spi->dev.of_node->name;
+
+ parent_name = of_clk_get_parent_name(spi->dev.of_node, 0);
+ if (!parent_name)
+ return -EINVAL;
+
+ init.ops = &adf4350_clk_ops;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+ init.flags = CLK_SET_RATE_PARENT;
+
+ st->hw.init = &init;
+ clk = devm_clk_register(&spi->dev, &st->hw);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ ret = of_clk_add_provider(spi->dev.of_node, of_clk_src_simple_get, clk);
+ if (ret)
+ return ret;
+
+ st->clkout = clk;
+
+ return devm_add_action_or_reset(&spi->dev, adf4350_clk_del_provider, st);
+}
+
static struct adf4350_platform_data *adf4350_parse_dt(struct device *dev)
{
struct adf4350_platform_data *pdata;
@@ -522,8 +637,6 @@ static int adf4350_probe(struct spi_device *spi)

indio_dev->info = &adf4350_info;
indio_dev->modes = INDIO_DIRECT_MODE;
- indio_dev->channels = &adf4350_chan;
- indio_dev->num_channels = 1;

mutex_init(&st->lock);

@@ -551,6 +664,18 @@ static int adf4350_probe(struct spi_device *spi)
return ret;
}

+ ret = adf4350_clk_register(st);
+ if (ret)
+ return ret;
+
+ if (st->clkout) {
+ indio_dev->channels = NULL;
+ indio_dev->num_channels = 0;
+ } else {
+ indio_dev->channels = &adf4350_chan;
+ indio_dev->num_channels = 1;
+ }
+
ret = devm_add_action_or_reset(&spi->dev, adf4350_power_down, indio_dev);
if (ret)
return dev_err_probe(&spi->dev, ret,
--
2.45.2