Re: [PATCH v3 07/11] dt-bindings: clock: Add StarFive JH7110 system clock and reset generator

Conor Dooley
2023-02-22T16:27:11Z

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On Wed, Feb 22, 2023 at 09:27:37PM +0800, Hal Feng wrote:
> On Tue, 21 Feb 2023 23:39:32 +0000, Conor Dooley wrote:
> > On Tue, Feb 21, 2023 at 02:17:17PM -0800, Stephen Boyd wrote:
> >> Quoting Conor Dooley (2023-02-16 10:20:34)
> >> > On Thu, Feb 16, 2023 at 10:42:20PM +0800, Hal Feng wrote:
> >> > > On Tue, 27 Dec 2022 20:15:20 +0000, Conor Dooley wrote:
> >> > > > On Mon, Dec 26, 2022 at 12:26:32AM +0800, Hal Feng wrote:
> >> > > Please see the picture of these external clocks in clock tree.
> >> > >
> >> > > # mount -t debugfs none /mnt
> >> > > # cat /mnt/clk/clk_summary
> >> > > enable prepare protect duty hardware
> >> > > clock count count count rate accuracy phase cycle enable
> >> > > -------------------------------------------------------------------------------------------------------
> >> > > *mclk_ext* 0 0 0 12288000 0 0 50000 Y
> >> > > *tdm_ext* 0 0 0 49152000 0 0 50000 Y
> >> > > *i2srx_lrck_ext* 0 0 0 192000 0 0 50000 Y
> >> > > *i2srx_bclk_ext* 0 0 0 12288000 0 0 50000 Y
> >> > > *i2stx_lrck_ext* 0 0 0 192000 0 0 50000 Y
> >> > > *i2stx_bclk_ext* 0 0 0 12288000 0 0 50000 Y
> >> > > *gmac1_rgmii_rxin* 0 0 0 125000000 0 0 50000 Y
> >> > > gmac1_rx 0 0 0 125000000 0 0 50000 Y
> >> > > gmac1_rx_inv 0 0 0 125000000 0 180 50000 Y
> >> > > *gmac1_rmii_refin* 0 0 0 50000000 0 0 50000 Y
> >> > > gmac1_rmii_rtx 0 0 0 50000000 0 0 50000 Y
> >> > > gmac1_tx 0 0 0 50000000 0 0 50000 N
> >> > > gmac1_tx_inv 0 0 0 50000000 0 180 50000 Y
> >> > > *osc* 4 4 0 24000000 0 0 50000 Y
> >> > > apb_func 0 0 0 24000000 0 0 50000 Y
> >> > > ...
> >> > >
> >> > > The clock "gmac1_rgmii_rxin" and the clock "gmac1_rmii_refin" are
> >> > > actually used as the parent of other clocks.
> >> >
> >> > > The "dummy" clocks
> >> > > you said are all internal clocks.
> >> >
> >> > No, what I meant by "dummy" clocks is that if you make clocks "required"
> >> > in the binding that are not needed by the hardware for operation a
> >> > customer of yours might have to add "dummy" clocks to their devicetree
> >> > to pass dtbs_check.
> >>
> >> They can set the phandle specifier to '<0>' to fill in the required
> >> property when there isn't anything there. If this is inside an SoC, it
> >> is always connected because silicon can't change after it is made
> >> (unless this is an FPGA). Therefore, any and all input clocks should be
> >> listed as required.
> >
> >> If the clk controller has inputs that are
> >> pads/balls/pins on the SoC then they can be optional if a valid design
> >> can leave those pins not connected.
> >
> > From the discussion on the dts patches, where the clocks have been put
> > (intentionally) into board.dts, I've been under the impression that we
> > are in this situation.
>
> For the system (sys) clock controller, we are in this situation.
> For the always-on (aon) clock controller, we are not, because some input
> clocks are inside the SoC.
>
> > Up to Hal to tell us if the hardware is capable of having those inputs
> > left unfilled!
>
> The situation is different for v1.2A and v1.3B boards.
>
> For the v1.2A board,
> gmac1 only requires "gmac1_rmii_refin", which support 100MHz
> gmac0 only requires "gmac0_rgmii_rxin", which support 1000MHz
>
> For the v1.3B board,
> gmac1 only requires "gmac1_rgmii_rxin", which support 1000MHz
> gmac0 only requires "gmac0_rgmii_rxin", which support 1000MHz
>
> So we should set the "required" property depending on different
> boards.

These were Krzk's suggestions:
oneOf:
- clock-names:
minItems: 3
items:
- a
- b
- c
- d
- clock-names:
items:
- a
- b
- d

or maybe:
- clock-names:
minItems: 3
items:
- a
- b
- enum: [c, d]
- d

Might be making a mess here, but I think that becomes:
clock-names:
oneOf:
- items:
- const: osc
- enum:
- gmac1_rmii_refin
- gmac1_rgmii_rxin
- const: i2stx_bclk_ext
- const: i2stx_lrck_ext
- const: i2srx_bclk_ext
- const: i2srx_lrck_ext
- const: tdm_ext
- const: mclk_ext

- items:
- const: osc
- const: gmac1_rmii_refin
- const: gmac1_rgmii_rxin
- const: i2stx_bclk_ext
- const: i2stx_lrck_ext
- const: i2srx_bclk_ext
- const: i2srx_lrck_ext
- const: tdm_ext
- const: mclk_ext

Cheers,
Conor.

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