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

Jolly Shah JOLLYS at xilinx.com
Wed Mar 7 14:47:08 PST 2018 

Hi Rob,


> -----Original Message-----
> From: Rob Herring [mailto:robh at kernel.org]
> Sent: Monday, March 05, 2018 5:46 PM
> To: Jolly Shah <JOLLYS at xilinx.com>
> Cc: mturquette at baylibre.com; sboyd at codeaurora.org;
> michal.simek at xilinx.com; mark.rutland at arm.com; linux-clk at vger.kernel.org;
> devicetree at vger.kernel.org; Shubhrajyoti Datta <shubhraj at xilinx.com>; linux-
> kernel at vger.kernel.org; Jolly Shah <JOLLYS at xilinx.com>; Rajan Vaja
> <RAJANV at xilinx.com>; linux-arm-kernel at lists.infradead.org
> Subject: Re: [PATCH 2/3] dt-bindings: clock: Add bindings for ZynqMP clock
> driver
> 
> 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 at xilinx.com>
> > Signed-off-by: Rajan Vaja <rajanv at xilinx.com>
> > Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta at xilinx.com>
> > ---
> >  .../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".
> 

Will correct description in next version.

> > +
> > +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.

Sure. Will move them.

> 
> > +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 are controlled by a dedicated platform management controller. Above clock ids are used to identify clocks between master and PMU.

> 
> > +	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
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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