Re: [PATCH 2/3] dt-bindings: clock: Add bindings for ZynqMP clock driver

From: Rob Herring
Date: Mon Mar 05 2018 - 20:49:02 EST

On Wed, Feb 28, 2018 at 02:27:40PM -0800, Jolly Shah wrote:
> Add documentation to describe Xilinx ZynqMP clock driver
> bindings.
>
> Signed-off-by: Jolly Shah <jollys@xxxxxxxxxx>
> Signed-off-by: Rajan Vaja <rajanv@xxxxxxxxxx>
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
> ---
> .../devicetree/bindings/clock/xlnx,zynqmp-clk.txt | 163 +++++++++++++++++++++
> 1 file changed, 163 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/xlnx,zynqmp-clk.txt
>
> diff --git a/Documentation/devicetree/bindings/clock/xlnx,zynqmp-clk.txt b/Documentation/devicetree/bindings/clock/xlnx,zynqmp-clk.txt
> new file mode 100644
> index 0000000..d590330
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/xlnx,zynqmp-clk.txt
> @@ -0,0 +1,163 @@
> +Device Tree Clock bindings for the Zynq Ultrascale+ MPSoC
> +
> +The Zynq Ultrascale+ MPSoC has several different clk providers,
> +each with there own bindings.
> +The purpose of this document is to document their usage.
> +
> +See clock_bindings.txt for more information on the generic clock bindings.
> +
> +== Clock Controller ==
> +The clock controller is a logical abstraction of Zynq Ultrascale+ MPSoC clock
> +tree. It reads required input clock frequencies from the devicetree and acts
> +as clock provider for all clock consumers of PS clocks.

Umm, the clock controller should correspond to a h/w block, not a
"logical abstraction of the clock tree".

> +
> +Required properties:
> + - #clock-cells : Must be 1
> + - compatible : "xlnx,zynqmp-clk"
> + - clocks : list of clock specifiers which are external input clocks to the
> + given clock controller. Please refer the next section to find
> + the input clocks for a given controller.
> + - clock-names : list of names of clocks which are exteral input clocks to the
> + given clock controller. Please refer to the clock bindings
> + for more details
> +
> +Input clocks for zynqmp Ultrascale+ clock controller:
> +The Zynq UltraScale+ MPSoC has one primary and four alternative reference clock
> +inputs.
> +These required clock inputs are the
> + - pss_ref_clk (PS reference clock)
> + - video_clk (reference clock for video system )
> + - pss_alt_ref_clk (alternative PS reference clock)
> + - aux_ref_clk
> + - gt_crx_ref_clk (transceiver reference clock)
> +
> +The following strings are optional parameters to the 'clock-names' property in
> +order to provide an optional (E)MIO clock source.
> + - swdt0_ext_clk
> + - swdt1_ext_clk
> + - gem0_emio_clk
> + - gem1_emio_clk
> + - gem2_emio_clk
> + - gem3_emio_clk
> + - mio_clk_XX # with XX = 00..77
> + - mio_clk_50_or_51 #for the mux clock to gem tsu from 50 or 51
> +
> +
> +Output clocks for zynqmp Ultrascale+ clock controller:
> +Output clocks are registered based on clock information received from firmware.
> +Output clock indexes are mentioned below:
> +
> +Clock ID: Output clock name:
> +-------------------------------------

These go in header definition, not here.

> +0 iopll
> +1 rpll
> +2 apll
> +3 dpll
> +4 vpll
> +5 iopll_to_fpd
> +6 rpll_to_fpd
> +7 apll_to_lpd
> +8 dpll_to_lpd
> +9 vpll_to_lpd
> +10 acpu
> +11 acpu_half
> +12 dbf_fpd
> +13 dbf_lpd
> +14 dbg_trace
> +15 dbg_tstmp
> +16 dp_video_ref
> +17 dp_audio_ref
> +18 dp_stc_ref
> +19 gdma_ref
> +20 dpdma_ref
> +21 ddr_ref
> +22 sata_ref
> +23 pcie_ref
> +24 gpu_ref
> +25 gpu_pp0_ref
> +26 gpu_pp1_ref
> +27 topsw_main
> +28 topsw_lsbus
> +29 gtgref0_ref
> +30 lpd_switch
> +31 lpd_lsbus
> +32 usb0_bus_ref
> +33 usb1_bus_ref
> +34 usb3_dual_ref
> +35 usb0
> +36 usb1
> +37 cpu_r5
> +38 cpu_r5_core
> +39 csu_spb
> +40 csu_pll
> +41 pcap
> +42 iou_switch
> +43 gem_tsu_ref
> +44 gem_tsu
> +45 gem0_ref
> +46 gem1_ref
> +47 gem2_ref
> +48 gem3_ref
> +49 gem0_tx
> +50 gem1_tx
> +51 gem2_tx
> +52 gem3_tx
> +53 qspi_ref
> +54 sdio0_ref
> +55 sdio1_ref
> +56 uart0_ref
> +57 uart1_ref
> +58 spi0_ref
> +59 spi1_ref
> +60 nand_ref
> +61 i2c0_ref
> +62 i2c1_ref
> +63 can0_ref
> +64 can1_ref
> +65 can0
> +66 can1
> +67 dll_ref
> +68 adma_ref
> +69 timestamp_ref
> +70 ams_ref
> +71 pl0_ref
> +72 pl1_ref
> +73 pl2_ref
> +74 pl3_ref
> +75 wdt
> +76 iopll_int
> +77 iopll_pre_src
> +78 iopll_half
> +79 iopll_int_mux
> +80 iopll_post_src
> +81 rpll_int
> +82 rpll_pre_src
> +83 rpll_half
> +84 rpll_int_mux
> +85 rpll_post_src
> +86 apll_int
> +87 apll_pre_src
> +88 apll_half
> +89 apll_int_mux
> +90 apll_post_src
> +91 dpll_int
> +92 dpll_pre_src
> +93 dpll_half
> +94 dpll_int_mux
> +95 dpll_post_src
> +96 vpll_int
> +97 vpll_pre_src
> +98 vpll_half
> +99 vpll_int_mux
> +100 vpll_post_src
> +101 can0_mio
> +102 can1_mio
> +
> +Example:
> +
> +clk: clk {
> + #clock-cells = <1>;
> + compatible = "xlnx,zynqmp-clk";

How do you control the clocks?

> + clocks = <&pss_ref_clk>, <&video_clk>, <&pss_alt_ref_clk>, <&aux_ref_clk>, <&gt_crx_ref_clk>;
> + clock-names = "pss_ref_clk", "video_clk", "pss_alt_ref_clk","aux_ref_clk", "gt_crx_ref_clk"
> +};
> --
> 2.7.4
>
>
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