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    SubjectRE: [RFC] usb issue on imx27: 3 clocks are needed
    Date


    > On Mon, Aug 18, 2014 at 05:00:59PM +0800, Peter Chen wrote:
    > > On Sat, Aug 16, 2014 at 05:38:30PM +0200, Philippe Reynes wrote:
    > > > Hi all,
    > > >
    > > > i.MX27's usb needs three clocks (usb_ipg_gate, usb_ahb_gate and
    > > > usb_div) but the current chipidea driver implementation, and
    > > > devicetree, provides only ipg and ahb. Consequently, if the
    > > > bootloader don't enable the last one, the kernel will crash.
    > > >
    > > > Our approach/idea is to add a second, optionnal, clock in
    > > > ci_hdrc_imx.c with 'per' name in devicetree and to add clock name
    > 'main_clk' for mandatory clock.
    > > > This approach it correct? Or an other approach seems better?
    > > > Thank you very much for your point of view.
    > > >
    > >
    > > It is ok for me to have ipg, ahb and per clocks at driver, but how can
    > > you maintain DT consistent?
    >
    > Adding new clock as optional one will just maintain the DT compatibility.
    >

    How to handle node_usb_soc1's clock which is without clk name to consistent with three
    clocks for node_usb_soc2 at driver? Except for adding some platform judge code at
    driver, do you have other solutions?

    node_usb_soc1: {
    clocks = <&clks IMX6_CLK_USBOH3>;
    };

    node_usb_soc2: {
    clocks = <&clks IMX27_CLK_USBIPG>, <&clks IMX27_CLK_USBOH3>, <&clks IMX27_CLK_USBPER>;
    clock-names = "ipg", "ahb", "per";
    };

    Peter


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