From e34812c5bac8de641a2551b5ccb601627c10e772 Mon Sep 17 00:00:00 2001 From: Tomeu Vizoso Date: Thu, 12 Mar 2015 15:47:56 +0100 Subject: of: document new emc-timings subnode in nvidia,tegra124-car The EMC clock needs some extra information for changing its rate. Signed-off-by: Tomeu Vizoso Signed-off-by: Thierry Reding --- .../bindings/clock/nvidia,tegra124-car.txt | 42 +++++++++++++++++++++- 1 file changed, 41 insertions(+), 1 deletion(-) (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt b/Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt index c6620bc..c3891ce 100644 --- a/Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt +++ b/Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt @@ -21,10 +21,31 @@ Required properties : In clock consumers, this cell represents the bit number in the CAR's array of CLK_RST_CONTROLLER_RST_DEVICES_* registers. +The node should contain a "emc-timings" subnode for each supported RAM type (see +field RAM_CODE in register PMC_STRAPPING_OPT_A). + +Required properties for "emc-timings" nodes : +- nvidia,ram-code : Should contain the value of RAM_CODE this timing set + is used for. + +Each "emc-timings" node should contain a "timing" subnode for every supported +EMC clock rate. + +Required properties for "timing" nodes : +- clock-frequency : Should contain the memory clock rate to which this timing +relates. +- nvidia,parent-clock-frequency : Should contain the rate at which the current +parent of the EMC clock should be running at this timing. +- clocks : Must contain an entry for each entry in clock-names. + See ../clocks/clock-bindings.txt for details. +- clock-names : Must include the following entries: + - emc-parent : the clock that should be the parent of the EMC clock at this +timing. + Example SoC include file: / { - tegra_car: clock { + tegra_car: clock@60006000 { compatible = "nvidia,tegra124-car"; reg = <0x60006000 0x1000>; #clock-cells = <1>; @@ -62,4 +83,23 @@ Example board file: &tegra_car { clocks = <&clk_32k> <&osc>; }; + + clock@60006000 { + emc-timings-3 { + nvidia,ram-code = <3>; + + timing-12750000 { + clock-frequency = <12750000>; + nvidia,parent-clock-frequency = <408000000>; + clocks = <&tegra_car TEGRA124_CLK_PLL_P>; + clock-names = "emc-parent"; + }; + timing-20400000 { + clock-frequency = <20400000>; + nvidia,parent-clock-frequency = <408000000>; + clocks = <&tegra_car TEGRA124_CLK_PLL_P>; + clock-names = "emc-parent"; + }; + }; + }; }; -- cgit v1.1