From c0d5b06f667c02e1c5784daf40cb858c73bdb9fa Mon Sep 17 00:00:00 2001 From: Tomasz Stanislawski Date: Tue, 15 Oct 2013 17:59:11 +0200 Subject: [PATCH] clk: propagate parent change up one level 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 Change-Id: I206d23fb86cc09bce943ef9971a710876e3a7744 --- 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 a9abf1b..ba2f31b 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1506,6 +1506,12 @@ 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 1186098..061052f 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -27,6 +27,7 @@ #define CLK_IS_ROOT BIT(4) /* root clk, has no parent */ #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_PARENT_PARENT BIT(7) /* propagate parent change up one level */ struct clk_hw; -- 2.7.4