Messages in this thread Patch in this message | | | Date | Fri, 8 Jun 2018 07:51:55 +0200 | From | Boris Brezillon <> | Subject | Re: [LINUX PATCH v9 1/4] Devicetree: Add pl353 smc controller devicetree binding information |
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On Fri, 8 Jun 2018 05:20:33 +0000 Naga Sureshkumar Relli <nagasure@xilinx.com> wrote:
> Hi Miquel, > > Thanks for the review. > > > -----Original Message----- > > From: Miquel Raynal [mailto:miquel.raynal@bootlin.com] > > Sent: Thursday, June 7, 2018 9:12 PM > > To: Naga Sureshkumar Relli <nagasure@xilinx.com> > > Cc: boris.brezillon@bootlin.com; richard@nod.at; wmw2@infradead.org; > > computersforpeace@gmail.com; marek.vasut@gmail.com; f.fainelli@gmail.com; > > mmayer@broadcom.com; rogerq@ti.com; ladis@linux-mips.org; ada@thorsis.com; > > honghui.zhang@mediatek.com; linux-mtd@lists.infradead.org; linux-kernel@vger.kernel.org; > > nagasureshkumarrelli@gmail.com > > Subject: Re: [LINUX PATCH v9 1/4] Devicetree: Add pl353 smc controller devicetree > > binding information > > > > Hi Naga, > > > > On Wed, 6 Jun 2018 13:19:39 +0530, Naga Sureshkumar Relli > > <naga.sureshkumar.relli@xilinx.com> wrote: > > > > > Add pl353 static memory controller devicetree binding information. > > > > > > Signed-off-by: Naga Sureshkumar Relli > > > <naga.sureshkumar.relli@xilinx.com> > > > --- > > > Changes in v9: > > > - Addressed commens given by Randy Dunlap and Miquel Raynal > > > > Can you please be more specific in your next changelog? I don't remember what I suggested a > > few months ago :) > Ok, I will update. > > > > > > Changes in v8: > > > - None > > > Changes in v7: > > > - Corrected clocks description > > > - prefixed '#' for address and size cells Changes in v6: > > > - None > > > Changes in v5: > > > - Removed timing properties > > > Changes in v4: > > > - none > > > Changes in v3: > > > - none > > > Changes in v2: > > > - modified timing binding info as per onfi timing parameters > > > - add suffix nano second as timing unit > > > - modified the clock names as per the IP spec > > > --- > > > .../bindings/memory-controllers/pl353-smc.txt | 53 > > ++++++++++++++++++++++ > > > 1 file changed, 53 insertions(+) > > > create mode 100644 > > > Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt > > > > > > diff --git > > > a/Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt > > > b/Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt > > > new file mode 100644 > > > index 0000000..551e66b > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/memory-controllers/pl353-smc.t > > > +++ xt > > > @@ -0,0 +1,53 @@ > > > +Device tree bindings for ARM PL353 static memory controller > > > + > > > +PL353 static memory controller supports two kinds of memory > > > +interfaces.i.e NAND and SRAM/NOR interfaces. > > > +The actual devices are instantiated from the child nodes of pl353 smc node. > > > + > > > +Required properties: > > > +- compatible : Should be "arm,pl353-smc-r2p1" > > I thing Rob prefers: > > > > - compatible: Must be one of: > > * arm, pl353-smc-r2p1 > Are you suggesting any other compatibles? > Or just a change from "should be to Must be one of"? > > > > > +- reg : Controller registers map and length. > > > +- clock-names : List of input clock names - "ref_clk", "aper_clk" > > > + (See clock bindings for details). > > > +- clocks : Clock phandles (see clock bindings for details). > > > +- address-cells : Address cells, must be 1. > > > +- size-cells : Size cells. Must be 1. > > > > Please avoid padding, just this is enough: > > > > - something: And another thing. > Ok, I will update it. > > > > > > + > > > +Child nodes: > > > + For NAND the "arm,pl353-nand-r2p1" and for NOR the "cfi-flash" > > > +drivers are supported as child nodes. > > > + > > > +Mandatory timing properties for child nodes: > > > +- arm,nand-cycle-t0 : Read cycle time(t_rc). > > > +- arm,nand-cycle-t1 : Write cycle time(t_wc). > > > +- arm,nand-cycle-t2 : re_n assertion delay(t_rea). > > > +- arm,nand-cycle-t3 : we_n de-assertion delay(t_wp). > > > +- arm,nand-cycle-t4 : Status read time(t_clr) > > > +- arm,nand-cycle-t5 : ID read time(t_ar) > > > +- arm,nand-cycle-t6 : busy to re_n(t_rr) > > > > I think this has nothing to do in the DT, you should handle timings from the - > > >setup_data_interface() hook. If you need, you may use different compatibles to distinguish > > different platform data. > > > This controller is applicable only to Zynq platform. No other platform will use this. > Basically pl353-smc.c and pl353-nand.c, both are different drivers. > And this data_interface hook is in nand, and to set this timings if we read it from setup_data_interface(), then > We need to make call from nand to smc driver. > Let me try this. > > > > + > > > +for nand partition information please refer the below file > > > > s/nand/NAND/ > I will update in next version. > > > > > > +Documentation/devicetree/bindings/mtd/partition.txt > > > + > > > +Example: > > > + pl353smcc_0: pl353smcc@e000e000 { > > > > Why not something more explicit with the '-flash-controller' suffix? > Is this ok? > smcc: memory-controller@e000e000 {} > > > > > > + compatible = "arm,pl353-smc-r2p1" > > > + clock-names = "memclk", "aclk"; > > > + clocks = <&clkc 11>, <&clkc 44>; > > > + reg = <0xe000e000 0x1000>; > > > + #address-cells = <1>; > > > + #size-cells = <1>; > > > + ranges; > > > + nand_0: nand@e1000000 { > > > + compatible = "arm,pl353-nand-r2p1" > > > > NAND chips do not have their own compatible. > As I said above, SMCC controller has two interface(NAND, NOR/SRAM). > So to differentiate which interface is selected, we added the compatible. > The dts node looks below. > smcc: memory-controller@e000e000 { > #address-cells = <1>; > #size-cells = <1>; > clock-names = "memclk", "aclk"; > clocks = <&clkc 11>, <&clkc 44>; > compatible = "arm,pl353-smc-r2p1"; > interrupt-parent = <&intc>; > interrupts = <0 18 4>; > ranges ; > reg = <0xe000e000 0x1000>; > nand0: flash@e1000000 { > compatible = "arm,pl353-nand-r2p1"; > reg = <0xe1000000 0x1000000>; > #address-cells = <0x1>; > #size-cells = <0x1>; > }; > nor0: flash@e2000000 { > compatible = "cfi-flash"; > reg = <0xe2000000 0x2000000>; > #address-cells = <1>; > #size-cells = <1>; > }; > };
This looks similar to what we have on at91 SoC with one memory controller and inside this memory controller a dedicated logic for NAND devices. We used a representation where the NAND controller logic is described as a subnode of the memory controller and then NAND chips are defined under this subnode [1].
[1]https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/mtd/atmel-nand.txt#L84
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