mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
311accb645
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@renesas.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
56 lines
2.1 KiB
Plaintext
56 lines
2.1 KiB
Plaintext
* 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
|
|
|
|
Example (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";
|
|
#clock-cells = <0>;
|
|
};
|