On 27 July 2016 at 08:26, Paul Burton <paul.bur...@imgtec.com> wrote: > Previously ns16550 compatible UARTs probed via device tree have needed > their device tree nodes to contain a clock-frequency property. An > alternative to this commonly used with Linux is to reference a clock via > a phandle. This patch allows U-Boot to support that, retrieving the > clock frequency by probing the appropriate clock device. > > For example, a system might choose to provide the UART base clock as a > reference to a clock common to multiple devices: > > sys_clk: clock { > compatible = "fixed-clock"; > #clock-cells = <0>; > clock-frequency = <10000000>; > }; > > uart0: uart@10000000 { > compatible = "ns16550a"; > reg = <0x10000000 0x1000>; > clocks = <&sys_clk>; > }; > > uart1: uart@10000000 { > compatible = "ns16550a"; > reg = <0x10001000 0x1000>; > clocks = <&sys_clk>; > }; > > This removes the need for the frequency information to be duplicated in > multiple nodes and allows the device tree to be more descriptive of the > system. > > Signed-off-by: Paul Burton <paul.bur...@imgtec.com> > > --- > > Changes in v2: > - Propogate non-ENODEV errors from clk_get_by_index > > drivers/serial/ns16550.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-)
This seems OK. I hope it does not bloat the code of any boards. Reviewed-by: Simon Glass <s...@chromium.org> _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot