| Message ID | 1408381705-3623-2-git-send-email-abrestic@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/18/2014 11:08 AM, Andrew Bresticker wrote: > Add device-tree bindings for the Tegra XUSB mailbox which will be used > for communication between the Tegra xHCI controller's firmware and the > host processor. > diff --git a/Documentation/devicetree/bindings/mailbox/nvidia,tegra124-xusb-mbox.txt b/Documentation/devicetree/bindings/mailbox/nvidia,tegra124-xusb-mbox.txt > +NVIDIA Tegra XUSB mailbox > +========================= > + > +The Tegra XUSB mailbox is used by the Tegra xHCI controller's firmware to > +communicate requests to the host and PHY drivers. > + > +Required properties: > +-------------------- > + - compatible: Should be "nvidia,tegra124-xusb-mbox". > + - reg: Address and length of the XUSB FPCI registers. > + - interrupts: XUSB mailbox interrupt. > + - #mbox-cells: Should be 1. The specifier is the index of the mailbox to > + reference. See <dt-bindings/mailbox/tegra-xusb-mailbox.h> for the list > + of valid values. Is there a common mailbox binding somewhere? I couldn't find one. While the text above specifies the value for #mbox-cells, it doesn't specify the details of what the property is used for (i.e. there's no documentation of the consumer-side of this property, for parsing the mboxes property). Typically, that would be part of a subsystem's common binding document, and that document would be referenced here. > diff --git a/include/dt-bindings/mailbox/tegra-xusb-mailbox.h b/include/dt-bindings/mailbox/tegra-xusb-mailbox.h > +#define TEGRA_XUSB_MBOX_CHAN_HOST 0 > +#define TEGRA_XUSB_MBOX_CHAN_PHY 1 I can't work out how these values relate to hardware at all. Are they in fact properties of the particular firmware that's loaded into the XUSB module? If so, I don't think the DT should contain these values at all. I wonder if the individual MBOX_CMD_* values from patch 2 are any better, although I think those are also defined by the firmware, not the hardware?
On 08/25/2014 12:48 PM, Stephen Warren wrote: > On 08/18/2014 11:08 AM, Andrew Bresticker wrote: >> Add device-tree bindings for the Tegra XUSB mailbox which will be used >> for communication between the Tegra xHCI controller's firmware and the >> host processor. > >> diff --git >> a/Documentation/devicetree/bindings/mailbox/nvidia,tegra124-xusb-mbox.txt >> b/Documentation/devicetree/bindings/mailbox/nvidia,tegra124-xusb-mbox.txt > >> +NVIDIA Tegra XUSB mailbox >> +========================= >> + >> +The Tegra XUSB mailbox is used by the Tegra xHCI controller's >> firmware to >> +communicate requests to the host and PHY drivers. >> + >> +Required properties: >> +-------------------- >> + - compatible: Should be "nvidia,tegra124-xusb-mbox". >> + - reg: Address and length of the XUSB FPCI registers. >> + - interrupts: XUSB mailbox interrupt. >> + - #mbox-cells: Should be 1. The specifier is the index of the >> mailbox to >> + reference. See <dt-bindings/mailbox/tegra-xusb-mailbox.h> for the >> list >> + of valid values. > > Is there a common mailbox binding somewhere? I couldn't find one. While > the text above specifies the value for #mbox-cells, it doesn't specify > the details of what the property is used for (i.e. there's no > documentation of the consumer-side of this property, for parsing the > mboxes property). Typically, that would be part of a subsystem's common > binding document, and that document would be referenced here. Ah, I see it's still being developed. I found it at: http://lkml.iu.edu/hypermail/linux/kernel/1408.0/00201.html It would be good to mention that the semantics of this property are defined by ../mailbox/mailbox.txt.
On Mon, Aug 25, 2014 at 11:48 AM, Stephen Warren <swarren@wwwdotorg.org> wrote: > On 08/18/2014 11:08 AM, Andrew Bresticker wrote: > >> diff --git a/include/dt-bindings/mailbox/tegra-xusb-mailbox.h >> b/include/dt-bindings/mailbox/tegra-xusb-mailbox.h > > >> +#define TEGRA_XUSB_MBOX_CHAN_HOST 0 >> +#define TEGRA_XUSB_MBOX_CHAN_PHY 1 > > > I can't work out how these values relate to hardware at all. Are they in > fact properties of the particular firmware that's loaded into the XUSB > module? If so, I don't think the DT should contain these values at all. Yes this is rather ugly... they're used by software for the demuxing of messages and don't correspond to actual hardware. > I wonder if the individual MBOX_CMD_* values from patch 2 are any > better, although I think those are also defined by the firmware, not the > hardware? They are indeed defined by the firmware, so this would become an issue if the firmware API ever changed.
diff --git a/Documentation/devicetree/bindings/mailbox/nvidia,tegra124-xusb-mbox.txt b/Documentation/devicetree/bindings/mailbox/nvidia,tegra124-xusb-mbox.txt new file mode 100644 index 0000000..c46219b --- /dev/null +++ b/Documentation/devicetree/bindings/mailbox/nvidia,tegra124-xusb-mbox.txt @@ -0,0 +1,30 @@ +NVIDIA Tegra XUSB mailbox +========================= + +The Tegra XUSB mailbox is used by the Tegra xHCI controller's firmware to +communicate requests to the host and PHY drivers. + +Required properties: +-------------------- + - compatible: Should be "nvidia,tegra124-xusb-mbox". + - reg: Address and length of the XUSB FPCI registers. + - interrupts: XUSB mailbox interrupt. + - #mbox-cells: Should be 1. The specifier is the index of the mailbox to + reference. See <dt-bindings/mailbox/tegra-xusb-mailbox.h> for the list + of valid values. + +Example: +-------- + mbox: mailbox@0,70098000 { + compatible = "nvidia,tegra124-xusb-mbox"; + reg = <0x0 0x70098000 0x0 0x1000>; + interrupts = <GIC_SPI 40 IRQ_TYPE_LEVEL_HIGH>; + + #mbox-cells = <1>; + }; + + usb@0,70090000 { + ... + mboxes = <&mbox TEGRA_XUSB_MBOX_CHAN_HOST>; + ... + }; diff --git a/include/dt-bindings/mailbox/tegra-xusb-mailbox.h b/include/dt-bindings/mailbox/tegra-xusb-mailbox.h new file mode 100644 index 0000000..59de6b0 --- /dev/null +++ b/include/dt-bindings/mailbox/tegra-xusb-mailbox.h @@ -0,0 +1,7 @@ +#ifndef _DT_BINDINGS_TEGRA_XUSB_MAILBOX_H +#define _DT_BINDINGS_TEGRA_XUSB_MAILBOX_H + +#define TEGRA_XUSB_MBOX_CHAN_HOST 0 +#define TEGRA_XUSB_MBOX_CHAN_PHY 1 + +#endif /* _DT_BINDINGS_TEGRA_XUSB_MAILBOX_H */
Add device-tree bindings for the Tegra XUSB mailbox which will be used for communication between the Tegra xHCI controller's firmware and the host processor. Signed-off-by: Andrew Bresticker <abrestic@chromium.org> --- Changes from v1: - Updated to use common mailbox bindings. --- .../bindings/mailbox/nvidia,tegra124-xusb-mbox.txt | 30 ++++++++++++++++++++++ include/dt-bindings/mailbox/tegra-xusb-mailbox.h | 7 +++++ 2 files changed, 37 insertions(+) create mode 100644 Documentation/devicetree/bindings/mailbox/nvidia,tegra124-xusb-mbox.txt create mode 100644 include/dt-bindings/mailbox/tegra-xusb-mailbox.h