Commit 0903ea60 authored by Boris BREZILLON's avatar Boris BREZILLON Committed by Mike Turquette

clk: add accuracy support for fixed clock

This patch adds support for accuracy retrieval on fixed clocks.
It also adds a new dt property called 'clock-accuracy' to define the clock
accuracy.

This can be usefull for oscillator (RC, crystal, ...) definitions which are
always given an accuracy characteristic.
Signed-off-by: default avatarBoris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: default avatarMike Turquette <mturquette@linaro.org>
parent 5279fc40
......@@ -10,6 +10,8 @@ Required properties:
- clock-frequency : frequency of clock in Hz. Should be a single cell.
Optional properties:
- clock-accuracy : accuracy of clock in ppb (parts per billion).
Should be a single cell.
- gpios : From common gpio binding; gpio connection to clock enable pin.
- clock-output-names : From common clock binding.
......@@ -18,4 +20,5 @@ Example:
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <1000000000>;
clock-accuracy = <100>;
};
......@@ -34,22 +34,31 @@ static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw,
return to_clk_fixed_rate(hw)->fixed_rate;
}
static unsigned long clk_fixed_rate_recalc_accuracy(struct clk_hw *hw,
unsigned long parent_accuracy)
{
return to_clk_fixed_rate(hw)->fixed_accuracy;
}
const struct clk_ops clk_fixed_rate_ops = {
.recalc_rate = clk_fixed_rate_recalc_rate,
.recalc_accuracy = clk_fixed_rate_recalc_accuracy,
};
EXPORT_SYMBOL_GPL(clk_fixed_rate_ops);
/**
* clk_register_fixed_rate - register fixed-rate clock with the clock framework
* clk_register_fixed_rate_with_accuracy - register fixed-rate clock with the
* clock framework
* @dev: device that is registering this clock
* @name: name of this clock
* @parent_name: name of clock's parent
* @flags: framework-specific flags
* @fixed_rate: non-adjustable clock rate
* @fixed_accuracy: non-adjustable clock rate
*/
struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
unsigned long fixed_rate)
struct clk *clk_register_fixed_rate_with_accuracy(struct device *dev,
const char *name, const char *parent_name, unsigned long flags,
unsigned long fixed_rate, unsigned long fixed_accuracy)
{
struct clk_fixed_rate *fixed;
struct clk *clk;
......@@ -70,16 +79,33 @@ struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
/* struct clk_fixed_rate assignments */
fixed->fixed_rate = fixed_rate;
fixed->fixed_accuracy = fixed_accuracy;
fixed->hw.init = &init;
/* register the clock */
clk = clk_register(dev, &fixed->hw);
if (IS_ERR(clk))
kfree(fixed);
return clk;
}
EXPORT_SYMBOL_GPL(clk_register_fixed_rate_with_accuracy);
/**
* clk_register_fixed_rate - register fixed-rate clock with the clock framework
* @dev: device that is registering this clock
* @name: name of this clock
* @parent_name: name of clock's parent
* @flags: framework-specific flags
* @fixed_rate: non-adjustable clock rate
*/
struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
unsigned long fixed_rate)
{
return clk_register_fixed_rate_with_accuracy(dev, name, parent_name,
flags, fixed_rate, 0);
}
EXPORT_SYMBOL_GPL(clk_register_fixed_rate);
#ifdef CONFIG_OF
......@@ -91,13 +117,18 @@ void of_fixed_clk_setup(struct device_node *node)
struct clk *clk;
const char *clk_name = node->name;
u32 rate;
u32 accuracy = 0;
if (of_property_read_u32(node, "clock-frequency", &rate))
return;
of_property_read_u32(node, "clock-accuracy", &accuracy);
of_property_read_string(node, "clock-output-names", &clk_name);
clk = clk_register_fixed_rate(NULL, clk_name, NULL, CLK_IS_ROOT, rate);
clk = clk_register_fixed_rate_with_accuracy(NULL, clk_name, NULL,
CLK_IS_ROOT, rate,
accuracy);
if (!IS_ERR(clk))
of_clk_add_provider(node, of_clk_src_simple_get, clk);
}
......
......@@ -204,6 +204,7 @@ struct clk_hw {
struct clk_fixed_rate {
struct clk_hw hw;
unsigned long fixed_rate;
unsigned long fixed_accuracy;
u8 flags;
};
......@@ -211,6 +212,9 @@ extern const struct clk_ops clk_fixed_rate_ops;
struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
unsigned long fixed_rate);
struct clk *clk_register_fixed_rate_with_accuracy(struct device *dev,
const char *name, const char *parent_name, unsigned long flags,
unsigned long fixed_rate, unsigned long fixed_accuracy);
void of_fixed_clk_setup(struct device_node *np);
......
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