From 0903ea60173fab226a867ceb080b2e0269a6c975 Mon Sep 17 00:00:00 2001 From: Boris BREZILLON Date: Sat, 21 Dec 2013 10:34:48 +0100 Subject: [PATCH] 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: Boris BREZILLON Signed-off-by: Mike Turquette --- .../devicetree/bindings/clock/fixed-clock.txt | 3 ++ drivers/clk/clk-fixed-rate.c | 43 ++++++++++++++++--- include/linux/clk-provider.h | 4 ++ 3 files changed, 44 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/clock/fixed-clock.txt b/Documentation/devicetree/bindings/clock/fixed-clock.txt index 0b1fe7824093..48ea0ad8ad46 100644 --- a/Documentation/devicetree/bindings/clock/fixed-clock.txt +++ b/Documentation/devicetree/bindings/clock/fixed-clock.txt @@ -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>; }; diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c index 1ed591ab8b1d..0fc56ab6e844 100644 --- a/drivers/clk/clk-fixed-rate.c +++ b/drivers/clk/clk-fixed-rate.c @@ -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); } diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 16d182c28ce6..5429f5db5037 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -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); -- 2.20.1