From: hdegoede@redhat•com (Hans de Goede)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 2/2] ehci-platform: Add support for clks and phy passed through devicetree
Date: Thu, 09 Jan 2014 14:26:30 +0100 [thread overview]
Message-ID: <52CEA386.6060103@redhat.com> (raw)
In-Reply-To: <20140108181632.GG2941@lukather>
Hi,
On 01/08/2014 07:16 PM, Maxime Ripard wrote:
> On Wed, Jan 08, 2014 at 05:30:08PM +0100, Hans de Goede wrote:
>> Currently ehci-platform is only used in combination with devicetree when used
>> with some via socs. By extending it to (optionally) get clks and a phy from
>> devicetree, and enabling / disabling those on power_on / off, it can be used
>> more generically. Specifically after this commit it can be used for the
>> ehci controller on Allwinner sunxi SoCs.
>>
>> Somehow we've ended up with 2 device-bindings documents for ehci-platform.c,
>> this patch renames and updates one to platform-ehci.txt to reflect that this
>> is a generic platform driver, and removes the other.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat•com>
>> ---
>> .../devicetree/bindings/usb/platform-ehci.txt | 25 ++++
>> .../devicetree/bindings/usb/via,vt8500-ehci.txt | 15 ---
>> .../devicetree/bindings/usb/vt8500-ehci.txt | 12 --
>> drivers/usb/host/ehci-platform.c | 126 +++++++++++++++++----
>> 4 files changed, 131 insertions(+), 47 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/usb/platform-ehci.txt
>> delete mode 100644 Documentation/devicetree/bindings/usb/via,vt8500-ehci.txt
>> delete mode 100644 Documentation/devicetree/bindings/usb/vt8500-ehci.txt
>>
>> diff --git a/Documentation/devicetree/bindings/usb/platform-ehci.txt b/Documentation/devicetree/bindings/usb/platform-ehci.txt
>> new file mode 100644
>> index 0000000..56c478d
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/usb/platform-ehci.txt
>> @@ -0,0 +1,25 @@
>> +Generic Platform EHCI controller
>> +
>> +Required properties:
>> +- compatible : "via,vt8500-ehci" or "wm,prizm-ehci"
>> +- reg : ehci controller register range (address and length)
>> +- interrupts : ehci controller interrupt
>> +
>> +Optional properties:
>> +- clocks : a list of phandle + clock specifier pairs, one for each entry
>> + in clock-names.
>> +- clock-names : "clk0", "clk1", ...
>> +- phys : phy
>> +- phy-names : "phy0"
>> +
>> +Example:
>> +
>> + ehci at d8007900 {
>> + compatible = "via,vt8500-ehci";
>> + reg = <0xd8007900 0x200>;
>> + interrupts = <43>;
>> + clocks = <&usb_clk 6>, <&ahb_gates 2>;
>> + clock-names = "clk0", "clk1";
>
> I'm really not convinced by this either. It prevents you from doing
> anything useful out of these clocks, and the only thing you can
> actually do with it is calling clk_get, and that's pretty much it.
>
> What if you some platform needs to adjust the rate of one of the two?
Then it needs its own driver. This is intended as a binding for a
*generic* driver, which is meant to cover simple straight forward
non-pci ohci cases. For more complex cases a separate driver will
need to be written.
I must say I'm becoming a bit unhappy with how the reviews of devicetree
bindings are being done. In one case it is not generic enough (ahci-sunxi).
If I then try to make it more generic in a case where that can actually
be done as the hardware is pretty straight forward, it is not specific enough.
You can simply not have both!
> Or wants to cut one but not the other for any reason?
This is another example of non generic behavior, requiring a separate
(small using the existing ohci core) platform glue driver, like the *19* we
already have.
Regards,
Hans
next prev parent reply other threads:[~2014-01-09 13:26 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-08 16:30 [PATCH v2 0/2] ohci and ehci-platform clks, phy and dt support Hans de Goede
2014-01-08 16:30 ` [PATCH v2 1/2] ohci-platform: Add support for devicetree instantiation Hans de Goede
2014-01-08 20:36 ` Florian Fainelli
2014-01-09 13:32 ` Hans de Goede
2014-01-08 16:30 ` [PATCH v2 2/2] ehci-platform: Add support for clks and phy passed through devicetree Hans de Goede
2014-01-08 18:16 ` Maxime Ripard
2014-01-09 13:26 ` Hans de Goede [this message]
2014-01-09 15:47 ` Alan Stern
2014-01-09 17:45 ` [linux-sunxi] " Hans de Goede
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