[PATCH v5 20/44] dt-bindings: clock: Add bindings for TI DA8XX USB PHY clocks

Sekhar Nori nsekhar at ti.com
Thu Jan 18 22:17:07 PST 2018


On Friday 19 January 2018 12:30 AM, David Lechner wrote:
> On 01/18/2018 06:10 AM, Sekhar Nori wrote:
>> On Monday 08 January 2018 07:47 AM, David Lechner wrote:
>>> This adds a new binding for TI DA8XX USB PHY clocks. These clocks are
>>> part
>>> of a syscon register called CFGCHIP3.
>>
>> CFGCHIP2
>>
>>>
>>> Signed-off-by: David Lechner <david at lechnology.com>
>>
>>> +Examples:
>>> +
>>> +    cfgchip: syscon at 1417c {
>>> +        compatible = "ti,da830-cfgchip", "syscon", "simple-mfd";
>>> +        reg = <0x1417c 0x14>;
>>> +
>>> +        usb0_phy_clk: usb0-phy-clock {
>>> +            compatible = "ti,da830-usb0-phy-clock";
>>> +            #clock-cells = <0>;
>>> +            clocks = <&usb_refclkin>, <&pll0_aux_clk>, <&psc1 1>;
>>> +            clock-names = "usb_refclkin", "auxclk", "usb0_lpsc";
>>> +            clock-output-names = "usb0_phy_clk";
>>
>> Probably call this "usb0_phy" to match with the input name used for
>> usb1_phy_clk?
> 
> I was planning on just dropping clock-output-names altogether actually
> since they don't really do anything useful.
> 
> Also, I was considering sending a series to change the con_id for the
> PHY clocks.
> 
> My current revision of the device tree bindings is looking like this:
> 
>     usb_phy: usb-phy {
>         compatible = "ti,da830-usb-phy";
>         #phy-cells = <1>;
>         clocks = <&usb_phy_clk 0>, <&usb_phy_clk 1>;
>         clock-names = "usb20_phy", "usb11_phy";
>         status = "disabled";
>     };
>     usb_phy_clk: usb-phy-clocks {
>         compatible = "ti,da830-usb-phy-clocks";
>         #clock-cells = <1>;
>         clocks = <&psc1 1>, <&usb_refclkin>, <&pll0_auxclk>;
>         clock-names = "fck", "usb_refclkin", "auxclk";
>     };
> 
> The clock-names = "usb20_phy", "usb11_phy" comes from the existing con_ids
> in the PHY driver's clk_get()s.
> 
> However, in device tree, we are usually referring to the USB devices as
> usb0 and usb1 instead of usb20 and usb11, respectively. Figure 6-2 "USB
> Clocking Diagram" in spruh82c.pdf (AM1808 TRM) calls these clocks "CLK48"
> and "CLK48MHz from USB 2.0 PHY", so I was thinking of changing the con_ids
> (and therefore also clock-names) to "usb0_clk48" and "usb1_clk48".

This is fine with me.

Thanks,
Sekhar



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