[ Upstream commit 60b8f0ddf1a927ef02141a6610fd52575134f821 ]
This adds clk_get_optional() and devm_clk_get_optional() functions to get
optional clocks.
They behave the same as (devm_)clk_get() except where there is no clock
producer. In this case, instead of returning -ENOENT, the function
returns NULL. This makes error checking simpler and allows
clk_prepare_enable, etc to be called on the returned reference
without additional checks.
Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Russell King <linux@armlinux.org.uk>
[sboyd@kernel.org: Document in devres.txt]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Stable-dep-of: a6191a3d1811 ("gpio: aspeed: Use devm_clk api to manage clock source")
Signed-off-by: Sasha Levin <sashal@kernel.org>