[PATCH v7 01/14] clk: fixed-factor: add optional accuracy support

Théo Lebrun
2024-02-21T18:22:14Z

Fixed factor clock reports the parent clock accuracy. Add flags and acc
fields to `struct clk_fixed_factor` to support setting a fixed
accuracy. The default if no flag is set is not changed: use the parent
clock accuracy.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
drivers/clk/clk-fixed-factor.c | 28 +++++++++++++++++++++-------
include/linux/clk-provider.h | 12 +++++++++++-
2 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index b3e66202b942..bc2644a9bd7d 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -57,10 +57,22 @@ static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
return 0;
}

+static unsigned long clk_factor_recalc_accuracy(struct clk_hw *hw,
+ unsigned long parent_accuracy)
+{
+ struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
+
+ if (fix->flags & CLK_FIXED_FACTOR_FIXED_ACCURACY)
+ return fix->acc;
+
+ return parent_accuracy;
+}
+
const struct clk_ops clk_fixed_factor_ops = {
.round_rate = clk_factor_round_rate,
.set_rate = clk_factor_set_rate,
.recalc_rate = clk_factor_recalc_rate,
+ .recalc_accuracy = clk_factor_recalc_accuracy,
};
EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);

@@ -81,7 +93,7 @@ __clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
const char *name, const char *parent_name,
const struct clk_hw *parent_hw, int index,
unsigned long flags, unsigned int mult, unsigned int div,
- bool devm)
+ unsigned long acc, unsigned int fixflags, bool devm)
{
struct clk_fixed_factor *fix;
struct clk_init_data init = { };
@@ -105,6 +117,8 @@ __clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
fix->mult = mult;
fix->div = div;
fix->hw.init = &init;
+ fix->acc = acc;
+ fix->flags = fixflags;

init.name = name;
init.ops = &clk_fixed_factor_ops;
@@ -152,7 +166,7 @@ struct clk_hw *devm_clk_hw_register_fixed_factor_index(struct device *dev,
unsigned int mult, unsigned int div)
{
return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, index,
- flags, mult, div, true);
+ flags, mult, div, 0, 0, true);
}
EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_index);

@@ -174,7 +188,7 @@ struct clk_hw *devm_clk_hw_register_fixed_factor_parent_hw(struct device *dev,
unsigned long flags, unsigned int mult, unsigned int div)
{
return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw,
- -1, flags, mult, div, true);
+ -1, flags, mult, div, 0, 0, true);
}
EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_parent_hw);

@@ -184,7 +198,7 @@ struct clk_hw *clk_hw_register_fixed_factor_parent_hw(struct device *dev,
{
return __clk_hw_register_fixed_factor(dev, NULL, name, NULL,
parent_hw, -1, flags, mult, div,
- false);
+ 0, 0, false);
}
EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_parent_hw);

@@ -193,7 +207,7 @@ struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
unsigned int mult, unsigned int div)
{
return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL, -1,
- flags, mult, div, false);
+ flags, mult, div, 0, 0, false);
}
EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);

@@ -240,7 +254,7 @@ struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
unsigned int mult, unsigned int div)
{
return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL, -1,
- flags, mult, div, true);
+ flags, mult, div, 0, 0, true);
}
EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);

@@ -267,7 +281,7 @@ static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
of_property_read_string(node, "clock-output-names", &clk_name);

hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, NULL, 0,
- 0, mult, div, false);
+ 0, mult, div, 0, 0, false);
if (IS_ERR(hw)) {
/*
* Clear OF_POPULATED flag so that clock registration can be
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 1293c38ddb7f..7ddc952c8c67 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -1084,18 +1084,28 @@ void of_fixed_factor_clk_setup(struct device_node *node);
* @hw: handle between common and hardware-specific interfaces
* @mult: multiplier
* @div: divider
+ * @acc: fixed accuracy in ppb
+ * @flags: behavior modifying flags
*
* Clock with a fixed multiplier and divider. The output frequency is the
* parent clock rate divided by div and multiplied by mult.
- * Implements .recalc_rate, .set_rate and .round_rate
+ * Implements .recalc_rate, .set_rate, .round_rate and .recalc_accuracy
+ *
+ * Flags:
+ * * CLK_FIXED_FACTOR_FIXED_ACCURACY - Use the value in @acc instead of the
+ * parent clk accuracy.
*/

struct clk_fixed_factor {
struct clk_hw hw;
unsigned int mult;
unsigned int div;
+ unsigned long acc;
+ unsigned int flags;
};

+#define CLK_FIXED_FACTOR_FIXED_ACCURACY BIT(0)
+
#define to_clk_fixed_factor(_hw) container_of(_hw, struct clk_fixed_factor, hw)

extern const struct clk_ops clk_fixed_factor_ops;

--
2.43.2