[PATCH 3/4] clk: Provide always-on clock support
From: Lee Jones <hidden>
Date: 2015-02-27 21:22:55
Also in:
linux-devicetree, lkml
Subsystem:
common clk framework, the rest · Maintainers:
Stephen Boyd, Brian Masney, Jerome Brunet, Linus Torvalds
Lots of platforms contain clocks which if turned off would prove fatal. The only way to recover from these catastrophic failures is to restart the board(s). Now, when a clock is registered with the framework it is compared against a list of provided always-on clock names which must be kept ungated. If it matches, we enable the existing CLK_IGNORE_UNUSED flag, which will prevent the common clk framework from attempting to gate it during the clk_disable_unused() procedure. Signed-off-by: Lee Jones <redacted> --- drivers/clk/clk.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 61c3fc5..3aab75e 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c@@ -2856,6 +2856,9 @@ int of_clk_add_provider(struct device_node *np, void *data) { struct of_clk_provider *cp; + struct property *prop; + struct clk *clk; + const char *clkname; int ret; cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
@@ -2875,6 +2878,14 @@ int of_clk_add_provider(struct device_node *np, if (ret < 0) of_clk_del_provider(np); + of_property_for_each_string(np, "clock-always-on", prop, clkname) { + clk = __clk_lookup(clkname); + if (!clk) + continue; + + clk->core->flags |= CLK_IGNORE_UNUSED; + } + return ret; } EXPORT_SYMBOL_GPL(of_clk_add_provider);
--
1.9.1