60b8f0ddf1
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>