From: Sven Van Asbroeck <thesven73@gmail.com>
To: Andy Duan <fugang.duan@nxp.com>
Cc: Fabio Estevam <festevam@gmail.com>,
Shawn Guo <shawnguo@kernel.org>, Rob Herring <robh+dt@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, netdev <netdev@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Sascha Hauer <s.hauer@pengutronix.de>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
dl-linux-imx <linux-imx@nxp.com>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [EXT] Re: [PATCH v5 3/3] ARM: imx6plus: optionally enable internal routing of clk_enet_ref
Date: Sun, 5 Jul 2020 11:34:18 -0400 [thread overview]
Message-ID: <CAGngYiWc8rNVEPC-8GK1yH4zXx7tgR9gseYaopu9GWDnSG1oyg@mail.gmail.com> (raw)
In-Reply-To: <AM6PR0402MB360781DA3F738C2DF445E821FF680@AM6PR0402MB3607.eurprd04.prod.outlook.com>
Hi Andy, thank you so much for your time and attention. See below.
On Sun, Jul 5, 2020 at 10:45 AM Andy Duan <fugang.duan@nxp.com> wrote:
>
> Don't consider it complex, GPR5[9] just select the rgmii gtx source from PAD or internal
> Like:
> GPR5[9] is cleared: PAD -> MAC gtx
> GPR5[9] is set: Pll_enet -> MAC gtx
> As you said, register one clock mux for the selection, assign the clock parent by board dts
> file, but now current clock driver doesn't support GPR clock.
Ok, so for imx6q plus only, we create two new clocks (MAC_GTX and PAD)
and a new clock mux, controlled by GPR5[9]:
enet_ref-o------>ext>---pad------| \
| |M |----mac_gtx
o-----------------------|_/
Where M = mux controlled by GPR5[9]
clk_mac_gtx -> clk_pad -> clk_enet_ref is the default. when a board
wants internal routing, it can just do:
&fec {
assigned-clocks = <&clks IMX6QDL_CLK_MAC_GTX>;
assigned-clock-parents = <&clks IMX6QDL_CLK_ENET_REF>;
};
But, how do we manage clk_pad? It is routed externally, and can be
connected to:
- enet_ref (typically via GPIO_16)
- an external oscillator
- an external PHY clock
ext phy---------| \
| |
enet_ref-o------|M |----pad------| \
| |_/ | |
| |M |----mac_gtx
| | |
o-----------------------|_/
How do we tell the clock framework that clk_pad has a mux that can
be connected to _any_ external clock? and also enet_ref?
next prev parent reply other threads:[~2020-07-05 15:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-02 17:53 [PATCH v5 1/3] ARM: imx: mach-imx6q: Search for fsl,imx6q-iomuxc-gpr earlier Sven Van Asbroeck
2020-07-02 17:53 ` [PATCH v5 2/3] dt-bindings: fec: add fsl,ptpclk-bypass-pad boolean property Sven Van Asbroeck
2020-07-02 17:53 ` [PATCH v5 3/3] ARM: imx6plus: optionally enable internal routing of clk_enet_ref Sven Van Asbroeck
2020-07-02 22:29 ` Fabio Estevam
2020-07-03 0:50 ` Sven Van Asbroeck
2020-07-03 2:01 ` [EXT] " Andy Duan
2020-07-04 14:08 ` Sven Van Asbroeck
2020-07-05 14:45 ` [EXT] " Andy Duan
2020-07-05 15:34 ` Sven Van Asbroeck [this message]
2020-07-06 5:30 ` Andy Duan
2020-07-06 13:46 ` Fabio Estevam
2020-07-06 14:58 ` Sven Van Asbroeck
2020-07-06 14:59 ` Sven Van Asbroeck
2020-07-07 3:38 ` Andy Duan
2020-07-07 15:21 ` Sven Van Asbroeck
2020-07-08 5:16 ` Andy Duan
2020-07-06 14:53 ` Sven Van Asbroeck
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