Hello. On 04/23/2014 02:02 PM, Kishon Vijay Abraham I wrote:
This PHY, though formally being a part of Renesas USBHS controller, contains the UGCTRL2 register that controls multiplexing of the USB ports (Renesas calls them channels) to the different USB controllers: channel 0 can be connected to either PCI EHCI/OHCI or USBHS controllers, channel 2 can be connected to PCI EHCI/OHCI or xHCI controllers.
This is a new driver for this USB PHY currently already supported under drivers/ usb/phy/. The reason for writing the new driver was the requirement that the multiplexing of USB channels to the controller be dynamic, depending on what USB drivers are loaded, rather than static as provided by the old driver. The infrastructure provided by drivers/phy/phy-core.c seems to fit that purpose ideally. The new driver only supports device tree probing for now.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
[...]
Index: linux-phy/drivers/phy/phy-rcar-gen2.c =================================================================== --- /dev/null +++ linux-phy/drivers/phy/phy-rcar-gen2.c @@ -0,0 +1,283 @@
[...]
+static int rcar_gen2_phy_probe(struct platform_device *pdev) +{
[...]
+ drv->phys[0][0].select_mask = USBHS_UGCTRL2_USB0SEL; + drv->phys[0][0].select_value = USBHS_UGCTRL2_USB0SEL_PCI; + drv->phys[0][1].select_mask = USBHS_UGCTRL2_USB0SEL; + drv->phys[0][1].select_value = USBHS_UGCTRL2_USB0SEL_HS_USB; + drv->phys[2][0].select_mask = USBHS_UGCTRL2_USB2SEL; + drv->phys[2][0].select_value = USBHS_UGCTRL2_USB2SEL_PCI; + drv->phys[2][1].select_mask = USBHS_UGCTRL2_USB2SEL; + drv->phys[2][1].select_value = USBHS_UGCTRL2_USB2SEL_USB30; + + for (i = 0; i < NUM_USB_CHANNELS; i++) {
Instead of hard coding the number of channels,
It's hard coded in the hardware. We can even decrease that number to 2 as
right, that's why thought dt should have that information.
So you want a dedicated property for that or you meant something else?
for the channel #1 we have nothing to do, regardless of whether it's present or not...
we can model the channels (PHYs) as sub-nodes of the main PHY
Hm, I don't think such representation would be adequate: the channels themselves do not usually correspond to any particular PHY, that's why I used #phy-cells = <2>.
in dt and use it to create individual PHYs.
Well, we probably can... however, I fail to see any immediate gain from it here... I have to ask why you've selected this particular driver for such DT representation experiments, despite it not being the first one supporting multiple PHYs?
just that it didn't strike before.. but I think all multiple PHYs should be modelled this way.
I've basically reimplemented the driver to parse the info from the subnodes and it's now became larger in size, not smaller. :-/ Overall, I'm not content with the changes, nor do I think such a change in the DT representation was a great idea...
Thanks Kishon
WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
