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. Best regards, Hal > > FWIW, there's a v4 [1] of this series - but the question has yet to be > resolved. > > Thanks, > Conor. > > 1 - https://lore.kernel.org/all/20230221024645.127922-1-hal.feng@xxxxxxxxxxxxxxxx/
