Re: [PATCH v5 20/44] dt-bindings: clock: Add bindings for TI DA8XX USB PHY clocks
From: Sekhar Nori
Date: Fri Jan 19 2018 - 01:18:30 EST
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@xxxxxxxxxxxxxx>
>>
>>> +Examples:
>>> +
>>> +ÂÂÂ cfgchip: syscon@1417c {
>>> +ÂÂÂÂÂÂÂ compatible = "ti,da830-cfgchip", "syscon", "simple-mfd";
>>> +ÂÂÂÂÂÂÂ reg = <0x1417c 0x14>;
>>> +
>>> +ÂÂÂÂÂÂÂ usb0_phy_clk: usb0-phy-clock {
>>> +ÂÂÂÂÂÂÂÂÂÂÂ compatible = "ti,da830-usb0-phy-clock";
>>> +ÂÂÂÂÂÂÂÂÂÂÂ #clock-cells = <0>;
>>> +ÂÂÂÂÂÂÂÂÂÂÂ clocks = <&usb_refclkin>, <&pll0_aux_clk>, <&psc1 1>;
>>> +ÂÂÂÂÂÂÂÂÂÂÂ clock-names = "usb_refclkin", "auxclk", "usb0_lpsc";
>>> +ÂÂÂÂÂÂÂÂÂÂÂ 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:
>
> ÂÂÂÂusb_phy: usb-phy {
> ÂÂÂÂÂÂÂ compatible = "ti,da830-usb-phy";
> ÂÂÂÂÂÂÂ #phy-cells = <1>;
> ÂÂÂÂÂÂÂ clocks = <&usb_phy_clk 0>, <&usb_phy_clk 1>;
> ÂÂÂÂÂÂÂ clock-names = "usb20_phy", "usb11_phy";
> ÂÂÂÂÂÂÂ status = "disabled";
> ÂÂÂÂ};
> ÂÂÂÂusb_phy_clk: usb-phy-clocks {
> ÂÂÂÂÂÂÂ compatible = "ti,da830-usb-phy-clocks";
> ÂÂÂÂÂÂÂ #clock-cells = <1>;
> ÂÂÂÂÂÂÂ clocks = <&psc1 1>, <&usb_refclkin>, <&pll0_auxclk>;
> ÂÂÂÂÂÂÂ clock-names = "fck", "usb_refclkin", "auxclk";
> ÂÂÂÂ};
>
> 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