clk: clock multiplexers may register out of order
authorMartin Fuzzey <mfuzzey@parkeon.com>
Thu, 22 Nov 2012 19:15:05 +0000 (20:15 +0100)
committerMike Turquette <mturquette@linaro.org>
Mon, 26 Nov 2012 19:14:45 +0000 (11:14 -0800)
commit1f61e5f143b578606389887887af549bc5554353
treeb49a23716e8896eac027f2730a4cf0d94983ec4f
parent45228ef32240957b1536fbba1ca12377cb2e587c
clk: clock multiplexers may register out of order

When a clock, C is initialised any orphan clocks listing C as
a possible parent are reparented to it regardless of the
parent requested by the orphan's get_parent() operation.

This means that multiplexers registered before their parents
are reparented to the first parent subsequently declared,
regardless of the selection made by the hardware registers.

For example:
static const char *sel[] = { "srcA", "srcB", "dummy", "srcC" };

child = clk_register_mux(NULL, "child",  sel, ARRAY_SIZE(sel), ...);
clk_register_fixed(NULL, "dummy", ...);
clk_register_fixed(NULL, "srcA", ...);
clk_register_fixed(NULL, "srcB", ...);
clk_register_fixed(NULL, "srcC", ...);

Causes child's parent to always be "dummy".

To fix this, when an orphanned clock has a get_parent() operation,
only reparent to the clock indicated by get_parent().

Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: improve $SUBJECT]
drivers/clk/clk.c