Re: [PATCH 1/4] usb: phy: add a new driver for usb3 phy

From: kishon
Date: Fri Oct 12 2012 - 05:08:47 EST


Hi Tony,

On Thursday 11 October 2012 06:29 AM, Tony Lindgren wrote:
Hi,

* Kishon Vijay Abraham I <kishon@xxxxxx> [120919 04:32]:
Added a driver for usb3 phy that handles the interaction between usb phy
device and dwc3 controller.

This also includes device tree support for usb3 phy driver and
the documentation with device tree binding information is updated.

Currently writing to control module register is taken care in this
driver which will be removed once the control module driver is in place.

You may be able to set up the control module register with one
of the following Linux standard frameworks:

1. Fixed regulator defined in mach-omap2/control.c

Is it control.c?

In this case the PHY driver can pick up the regulator by name.

Do you mean we have to define something like fixed_voltage_config defined in board-4430sdp.c?
From whatever I could make out from regulator/fixed.c, enabling/disabling of regulator is done using only gpio. I'm not sure how we can use that to write to control module register.

2. A mux mapped with pinctrl framework using pinctrl-single,bits
binding

And in this case the PHY driver can request the named pinctrl
states like "enabled" and "disabled".

--- a/Documentation/devicetree/bindings/usb/usb-phy.txt
+++ b/Documentation/devicetree/bindings/usb/usb-phy.txt
@@ -15,3 +15,21 @@ usb2phy@4a0ad080 {
reg = <0x4a0ad080 0x58>,
<0x4a002300 0x4>;
};

The comments also apply to the omap_usb2.c driver for
0x4a002300 above.

+
+OMAP USB3 PHY
+
+Required properties:
+ - compatible: Should be "ti,omap-usb3"
+ - reg : Address and length of the register set for the device. Also
+add the address of control module phy power register until a driver for
+control module is added
+
+This is usually a subnode of ocp2scp to which it is connected.
+
+usb3phy@4a084400 {
+ compatible = "ti,omap-usb3";
+ reg = <0x0x4a084400 0x80>,
+ <0x4a084800 0x64>,
+ <0x4a084c00 0x40>,
+ <0x4a002370 0x4>;
+};

And register 0x4a002370 here. Care to post some info what the
0x4a002370 register bits do? Is that same as CONTROL_DEV_CONF
on omap4, or does it have other bits there too?

It's CONTROL_PHY_POWER_USB register and it's structure looks like this.
31:22 USB_PWRCTL_CLK_FREQ
21:14 USB_PWRCTL_CLK_CMD
13:0 RESERVED

CLK_CMD takes values to power up/down the TX and RX in various combinations.

And CLK_FREQ takes values for clock configuration.

Thanks
Kishon
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/