iio: frequency: adf4350: add clk provider

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>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240621121403.47912-2-antoniu.miclaus@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/frequency/adf4350.c b/drivers/iio/frequency/adf4350.c
index 4abf80f75ef5d9bf20676ca7b8d10583d62869b7..e13e64a5164c14eac7c888634227f473eca7e61c 100644 (file)
--- 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 +387,113 @@ 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;
+
+       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_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 +635,6 @@ 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 +662,15 @@ 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 = &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,