[PATCH V3] ARM: tegra: Define Tegra20 CAR binding
From: Stephen Warren <hidden>
Date: 2012-02-15 18:14:27
Also in:
linux-devicetree
Subsystem:
common clk framework, open firmware and flattened device tree bindings, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
The Tegra20 CAR (Clock And Reset) Controller controls most aspects of most clocks within Tegra20. The device tree binding models this as a single monolithic clock provider, which exports ~130 clocks. This reduces the number of nodes needed in device tree to represent these clocks. This binding is only useful for Tegra20; the set of clocks that exists on Tegra30 is sufficiently different to merit its own binding. Signed-off-by: Stephen Warren <redacted> --- v3: * Re-order clock ID list so that IDs 0..95 match the CLK_OUT_ENB register layout where possible. For register bits that affect multiple clocks, assign those clocks IDs outside the range to make this clear. * Double-checked the documentation, and added a couple more cases where a single CLK_OUT_ENB bit affects multiple clocks. * Split the binding example into separate SoC and board file sections. v2: * Remove clock-names, clock-output-names properties; Tegra will solely use integer IDs for clocks in DT. * Fixed typo in compatible flag * Resolve FIXME re: multiple clocks with the same "reset ID"; give each unique clock an ID, and ignore the reset bits, since this is purely a clock binding. Code (e.g. U-Boot) that wants to use this to determine CAR reset bit numbers would need a table to convert from the clock IDs in this binding to the related reset bit number, if any. In general, I think that's true, and the U-Boot code that handles "peripheral IDs" should be reworked to handle "clocks", the peripheral clocks being a subset of all clocks. * Define clock IDs for all the non-peripheral clocks too; inputs, PLLs, etc. * Separate tegra-seaboard.dts usage example into a separate patch. This patch conceptually relies on Grant Likely's common clock binding patch series. However, since that seems pretty stable and people agree with it, I think we can check in this patch without waiting for Grant's. --- .../bindings/clock/nvidia,tegra20-car.txt | 207 ++++++++++++++++++++ arch/arm/boot/dts/tegra20.dtsi | 6 + 2 files changed, 213 insertions(+), 0 deletions(-) create mode 100644 Documentation/devicetree/bindings/clock/nvidia,tegra20-car.txt
diff --git a/Documentation/devicetree/bindings/clock/nvidia,tegra20-car.txt b/Documentation/devicetree/bindings/clock/nvidia,tegra20-car.txt
new file mode 100644
index 0000000..5c07fca
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/nvidia,tegra20-car.txt@@ -0,0 +1,207 @@ +NVIDIA Tegra20 Clock And Reset Controller + +This binding uses the common clock binding: +Documentation/devicetree/bindings/clock/clock-bindings.txt + +The CAR (Clock And Reset) Controller on Tegra is the HW module responsible +for muxing and gating Tegra's clocks, and setting their rates. + +Required properties : +- compatible : Should be "nvidia,tegra20-car" +- reg : Should contain CAR registers location and length +- clocks : Should contain phandle and clock specifiers for two clocks: + the 32 KHz "32k_in", and the board-specific oscillator "osc". +- #clock-cells : Should be 1. + In clock consumers, this cell represents the clock ID exposed by the CAR. + + The first 96 clocks are numbered to match the bits in the CAR's CLK_OUT_ENB + registers. These IDs often match those in the CAR's RST_DEVICES registers, + but not in all cases. Some bits in CLK_OUT_ENB affect multiple clocks. In + this case, those clocks are assigned IDs above 95 in order to highlight + this issue. Implementations that interpret these clock IDs as bit values + within the CLK_OUT_ENB or RST_DEVICES registers should be careful to + explicitly handle these special cases. + + The balance of the clocks controlled by the CAR are assigned IDs of 96 and + above. + + 0 cpu + 1 unassigned + 2 unassigned + 3 ac97 + 4 rtc + 5 tmr + 6 uart1 + 7 unassigned (register bit affects uart2 and vfir) + 8 gpio + 9 sdmmc2 + 10 unassigned (register bit affects spdif_in and spdif_out) + 11 i2s1 + 12 i2c1 + 13 ndflash + 14 sdmmc1 + 15 sdmmc4 + 16 twc + 17 pwm + 18 i2s2 + 19 epp + 20 unassigned (register bit affects vi and vi_sensor) + 21 2d + 22 usbd + 23 isp + 24 3d + 25 ide + 26 disp2 + 27 disp1 + 28 host1x + 29 vcp + 30 unassigned + 31 cache2 + + 32 mem + 33 ahbdma + 34 apbdma + 35 unassigned + 36 kbc + 37 stat_mon + 38 pmc + 39 fuse + 40 kfuse + 41 sbc1 + 42 snor + 43 spi1 + 44 sbc2 + 45 xio + 46 sbc3 + 47 dvc + 48 dsi + 49 unassigned (register bit affects tvo and cve) + 50 mipi + 51 hdmi + 52 csi + 53 tvdac + 54 i2c2 + 55 uart3 + 56 unassigned + 57 emc + 58 usb2 + 59 usb3 + 60 mpe + 61 vde + 62 bsea + 63 bsev + + 64 speedo + 65 uart4 + 66 uart5 + 67 i2c3 + 68 sbc4 + 69 sdmmc3 + 70 pcie + 71 owr + 72 afi + 73 csite + 74 unassigned + 75 avpucq + 76 la + 77 unassigned + 78 unassigned + 79 unassigned + 80 unassigned + 81 unassigned + 82 unassigned + 83 unassigned + 84 irama + 85 iramb + 86 iramc + 87 iramd + 88 cram2 + 89 audio_2x a/k/a audio_2x_sync_clk + 90 clk_d + 91 unassigned + 92 sus + 93 cdev1 + 94 cdev2 + 95 unassigned + + 96 uart2 + 97 vfir + 98 spdif_in + 99 spdif_out + 100 vi + 101 vi_sensor + 102 tvo + 103 cve + 104 osc + 105 clk_32k a/k/a clk_s + 106 clk_m + 107 sclk + 108 cclk + 109 hclk + 110 pclk + 111 blink + 112 pll_a + 113 pll_a_out0 + 114 pll_c + 115 pll_c_out1 + 116 pll_d + 117 pll_d_out0 + 118 pll_e + 119 pll_m + 120 pll_m_out1 + 121 pll_p + 122 pll_p_out1 + 123 pll_p_out2 + 124 pll_p_out3 + 125 pll_p_out4 + 126 pll_s + 127 pll_u + 128 pll_x + 129 cop a/k/a avp + 130 audio a/k/a audio_sync_clk + +Example SoC include file: + +/ { + tegra_car: clock@60006000 { + compatible = "nvidia,tegra20-car"; + reg = <0x60006000 0x1000>; + #clock-cells = <1>; + }; + + usb@c5004000 { + clocks = <&tegra_car 58>; /* usb2 */ + }; +}; + +Example board file: + +/ { + clocks { + #address-cells = <1>; + #size-cells = <0>; + + osc: clock { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <12000000>; + }; + }; + + i2c@7000d000 { + pmic@34 { + compatible = "ti,tps6586x"; + reg = <0x34>; + + clk_32k: clock { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <32768>; + }; + }; + }; + + &tegra_car { + clocks = <&clk_32k> <&osc>; + }; +};
diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
index ec1f010..550da98 100644
--- a/arch/arm/boot/dts/tegra20.dtsi
+++ b/arch/arm/boot/dts/tegra20.dtsi@@ -4,6 +4,12 @@ compatible = "nvidia,tegra20"; interrupt-parent = <&intc>; + tegra_car: clock@60006000 { + compatible = "nvidia,tegra20-car"; + reg = <0x60006000 1000>; + #clock-cells = <1>; + }; + pmc@7000f400 { compatible = "nvidia,tegra20-pmc"; reg = <0x7000e400 0x400>;
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1.7.0.4