diff options
author | Maxime Ripard <maxime.ripard@free-electrons.com> | 2014-07-14 11:53:27 (GMT) |
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committer | Maxime Ripard <maxime.ripard@free-electrons.com> | 2014-09-27 06:57:51 (GMT) |
commit | 9824cf73c3a5e677bee6fcba43c4807e01ff1b4a (patch) | |
tree | c65ac6ebd96730efdc45d405dcacd85a0bed7b28 | |
parent | 355bb165cd8bad2500df37437a9121f0177b6741 (diff) | |
download | linux-9824cf73c3a5e677bee6fcba43c4807e01ff1b4a.tar.xz |
clk: Add a function to retrieve phase
The current phase API doesn't look into the actual hardware to get the phase
value, but will rather get it from a variable only set by the set_phase
function.
This will cause issue when the client driver will never call the set_phase
function, where we can end up having a reported phase that will not match what
the hardware has been programmed to by the bootloader or what phase is
programmed out of reset.
Add a new get_phase function for the drivers to implement so that we can get
this value.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
-rw-r--r-- | drivers/clk/clk.c | 10 | ||||
-rw-r--r-- | include/linux/clk-provider.h | 5 |
2 files changed, 15 insertions, 0 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index d87661a..113d75d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1934,6 +1934,16 @@ int __clk_init(struct device *dev, struct clk *clk) clk->accuracy = 0; /* + * Set clk's phase. + * Since a phase is by definition relative to its parent, just + * query the current clock phase, or just assume it's in phase. + */ + if (clk->ops->get_phase) + clk->phase = clk->ops->get_phase(clk->hw); + else + clk->phase = 0; + + /* * Set clk's rate. The preferred method is to use .recalc_rate. For * simple clocks and lazy developers the default fallback is to use the * parent's rate. If a clock doesn't have a parent (or is orphaned) diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 69b20d4..abec961 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -130,6 +130,10 @@ struct dentry; * set then clock accuracy will be initialized to parent accuracy * or 0 (perfect clock) if clock has no parent. * + * @get_phase: Queries the hardware to get the current phase of a clock. + * Returned values are 0-359 degrees on success, negative + * error codes on failure. + * * @set_phase: Shift the phase this clock signal in degrees specified * by the second argument. Valid values for degrees are * 0-359. Return 0 on success, otherwise -EERROR. @@ -182,6 +186,7 @@ struct clk_ops { unsigned long parent_rate, u8 index); unsigned long (*recalc_accuracy)(struct clk_hw *hw, unsigned long parent_accuracy); + int (*get_phase)(struct clk_hw *hw); int (*set_phase)(struct clk_hw *hw, int degrees); void (*init)(struct clk_hw *hw); int (*debug_init)(struct clk_hw *hw, struct dentry *dentry); |