On Wed, Jun 28, 2017 at 03:28:35PM +0900, Yoshihiro Shimoda wrote: > R-Car USB 2.0 controller can change the clock source from an oscillator > to an external clock via a register. So, this patch adds support > the clock source selector as a clock driver. > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> > --- > This patch is based on the renesas-drivers.git / > renesas-drivers-2017-06-27-v4.12-rc7 tag. > > Changes from v1: > - Change this driver as a clock driver from a generic phy driver. > https://patchwork.kernel.org/patch/9788697/ > - Remove "RFC" tag. > > .../bindings/clock/renesas,rcar-usb2-clock-sel.txt | 54 ++++++ > drivers/clk/renesas/Kconfig | 5 + > drivers/clk/renesas/Makefile | 1 + > drivers/clk/renesas/rcar-usb2-clock-sel.c | 205 +++++++++++++++++++++ > 4 files changed, 265 insertions(+) > create mode 100644 Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > create mode 100644 drivers/clk/renesas/rcar-usb2-clock-sel.c > > diff --git a/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > new file mode 100644 > index 0000000..75ccafc > --- /dev/null > +++ b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > @@ -0,0 +1,54 @@ > +* Renesas R-Car USB 2.0 clock selector > + > +This file provides information on what the device node for the R-Car USB 2.0 > +clock selector. > + > +If you connect an external clock to the USB_EXTAL pin only, you should set > +the clock rate to "usb_extal" node only. > +If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module > +is not needed because this is default setting. (Of course, you can set the > +clock rates to both "usb_extal" and "usb_xtal" nodes. > + > +Case 1: An external clock connects to R-Car SoC > + +----------+ +--- R-Car ---------------------+ > + |External |---|USB_EXTAL ---> all usb channels| > + |clock | |USB_XTAL | > + +----------+ +-------------------------------+ > +In this case, we need this driver with "usb_extal" clock. > + > +Case 2: An oscillator connects to R-Car SoC > + +----------+ +--- R-Car ---------------------+ > + |Oscillator|---|USB_EXTAL -+-> all usb channels| > + | |---|USB_XTAL --+ | > + +----------+ +-------------------------------+ > +In this case, we don't need this selector. > + > +Required properties: > +- compatible: "renesas,r8a7795-rcar-usb2-clock-sel" if the device is a part of > + an R8A7795 SoC. > + "renesas,r8a7796-rcar-usb2-clock-sel" if the device if a part of > + an R8A7796 SoC. > + "renesas,rcar-gen3-usb2-clock-sel" for a generic R-Car Gen3 > + compatible device. > + > + When compatible with the generic version, nodes must list the > + SoC-specific version corresponding to the platform first > + followed by the generic version. > + > +- reg: offset and length of the USB 2.0 clock selector register block. > +- clocks: A list of phandles and specifier pairs. > +- clock-names: Name of the clocks. > + - The functional clock must be "ehci_ohci" > + - The USB_EXTAL clock pin must be "usb_extal" > + - The USB_XTAL clock pin must be "usb_xtal" > +- #clock-cells: Must be 0 > + > +Exxample (R-Car H3): > + > + usb2_clksel: clock-controller@e6590630 { > + compatible = "renesas,r8a77950-rcar-usb2-clock-sel", > + "renesas,rcar-gen3-usb2-clock-sel"; > + reg = <0 0xe6590630 0 0x02>; > + clocks = <&cpg CPG_MOD 703>, <&usb_extal>, <&usb_xtal>; > + clock-names = "ehci_ohci", "usb_extal", "usb_xtal"; Missing #clock-cells With that, for the binding: Acked-by: Rob Herring <robh@xxxxxxxxxx> Rob
