This patch adds support for propagation of setup of clock's parent one level up.
This feature is helpful when a driver changes topology of its clocks using clk_set_parent(). The problem occurs when on one platform/SoC driver's clock is located at MUX output but on the other platform/SoC there is a gated proxy clock between the MUX and driver's clock. In such a case, driver's code has to be modified to use one clock for enabling and the other clock for setup of a parent.
The code updates are avoided by propagating setup of a parent up one level.
Additionally, this patch adds CLK_SET_PARENT_PARENT (sorry for naming) flag to inform clk-core that clk_set_parent() should be propagated.
Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com --- drivers/clk/clk.c | 6 ++++++ include/linux/clk-provider.h | 1 + 2 files changed, 7 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index a004769..14eda80 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1595,6 +1595,12 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
/* try finding the new parent index */ if (parent) { + if ((clk->flags & CLK_SET_PARENT_PARENT) + && clk->num_parents == 1) { + ret = clk_set_parent(clk->parent, parent); + goto out; + } + p_index = clk_fetch_parent_index(clk, parent); p_rate = parent->rate; if (p_index == clk->num_parents) { diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 73bdb69..83c98d5 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -29,6 +29,7 @@ #define CLK_IS_BASIC BIT(5) /* Basic clk, can't do a to_clk_foo() */ #define CLK_GET_RATE_NOCACHE BIT(6) /* do not use the cached clk rate */ #define CLK_SET_RATE_NO_REPARENT BIT(7) /* don't re-parent on rate change */ +#define CLK_SET_PARENT_PARENT BIT(8) /* propagate parent change up one level */
struct clk_hw;