From: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public•gmane.org>
To: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public•gmane.org
Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public•gmane.org>,
Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public•gmane.org>,
Pawel Moll <pawel.moll-5wv7dgnIgG8@public•gmane.org>,
Ian Campbell
<ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public•gmane.org>,
Kumar Gala <galak-sgV2jX0FEOL9JmXXK+q4OQ@public•gmane.org>,
Linus Walleij
<linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public•gmane.org>,
Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public•gmane.org>,
"John W. Linville"
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Arnd Bergmann <arnd-r2nGTMty4D4@public•gmane.org>,
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Mika Westerberg
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Alexandre Courbot
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Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public•gmane.org>,
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linux-wireless
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netdev <netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>,
linux-arm-kernel
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devicetree <devicetree-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>,
Subject: Re: Re: [PATCH 7/7] ARM: sun7i: cubietruck: enable bluetooth module
Date: Wed, 16 Apr 2014 15:09:22 +0200 [thread overview]
Message-ID: <534E8102.4070404@redhat.com> (raw)
In-Reply-To: <CAGb2v67HzB22a3huRRZyufXkdTFE410MhXqAHyC-MmVo0-GCFA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
Hi,
On 04/16/2014 12:39 PM, Chen-Yu Tsai wrote:
> Hi,
>
> On Wed, Apr 16, 2014 at 5:44 PM, Maxime Ripard
> <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public•gmane.org> wrote:
>> Hi,
>>
>> Please try to keep me in CC, even though the ML doesn't make it easy..
>
> Sorry about that.
>
>> On Wed, Apr 16, 2014 at 12:06:59AM +0800, Chen-Yu Tsai wrote:
>>>>> @@ -139,4 +152,16 @@
>>>>> reg_usb2_vbus: usb2-vbus {
>>>>> status = "okay";
>>>>> };
>>>>> +
>>>>> + rfkill_bt {
>>>>> + compatible = "rfkill-gpio";
>>>>> + pinctrl-names = "default";
>>>>> + pinctrl-0 = <&bt_pwr_pin_cubietruck>, <&clk_out_a_pins_a>;
>>>>> + clocks = <&clk_out_a>;
>>>>> + clock-frequency = <32768>;
>>>>> + gpios = <&pio 7 18 0>; /* PH18 */
>>>>> + gpio-names = "reset";
>>>>> + rfkill-name = "bt";
>>>>> + rfkill-type = <2>;
>>>>> + };
>>>>
>>>> Hmmm, I don't think that's actually right.
>>>>
>>>> If you have such a device, then I'd expect it to be represented as a
>>>> full device in the DT, probably with one part for the WiFi, one part
>>>> for the Bluetooth, and here the definition of the rfkill device that
>>>> controls it.
>>>
>>> The AP6210 is not one device, but 2 separate chips in one module. Each
>>> chip has its own controls and interface. They just so happen to share
>>> the same enclosure. Even 2-in-1 chips by Broadcom have separate controls
>>> and interfaces. The WiFi side is most likely connected via SDIO, while
>>> the Bluetooth side is connected to a UART, and optionally I2S for sound.
>>
>> It's even easier to represent then.
>>
>>>> But tying parts of the device to the rfkill that controls it, such as
>>>> the clocks, or the frequency it runs at seems just wrong.
>>>
>>> I understand where you're coming from. For devices on buses that require
>>> drivers (such as USB, SDIO) these properties probably should be tied to
>>> the device node.
>>>
>>> For our use case here, which is a bluetooth chip connected on the UART,
>>> there is no in kernel representation or driver to tie them to. Same goes
>>> for UART based GPS chips. They just so happen to require toggling a GPIO,
>>> and maybe enabling a specific clock, to get it running. Afterwards,
>>> accessing it is done solely from userspace. For our Broadcom chips, the
>>> user has to upload its firmware first, then designate the tty as a Bluetooth
>>> HCI using hciattach.
>>>
>>> We are using the rfkill device as a on-off switch.
>>
>> I understand your point, but the fact that it's implemented in
>> user-space, or that UART is not a bus (which probably should be), is
>> only a Linux specific story, and how it's implemented in Linux (even
>> if the whole rfkill node is another one, but let's stay on topic).
>
> I gave it some thought last night. You are right. My whole approach
> is wrong. But let's try to make it right.
>
> So considering the fact that it's primarily connected to a UART,
> maybe I should make it a sub-node to the UART node it's actually
> connected to? Something like:
>
> uart2: serial@01c28800 {
> pinctrl-names = "default";
> pinctrl-0 = <&uart2_pins_a>;
> status = "okay";
>
> bt: bt_hci {
> compatible = "brcm,bcm20710";
> /* maybe add some generic compatible */
> pinctrl-names = "default";
> pinctrl-0 = <&clk_out_a_pins_a>,
> <&bt_pwr_pin_cubietruck>;
> clocks = <&clk_out_a>;
> clock-frequency = <32768>;
> gpios = <&pio 7 18 0>; /* PH18 */
> };
> };
>
> And let the uart core handle power sequencing for sub-nodes.
Great, I missed this reply when I typed my mail I send a few minutes
ago. I agree that this approach is how thing should be.
Regards,
Hans
next prev parent reply other threads:[~2014-04-16 13:09 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-15 6:41 [PATCH 0/7] net: rfkill: gpio: Add device tree support Chen-Yu Tsai
[not found] ` <1397544101-18135-1-git-send-email-wens-jdAy2FN1RRM@public.gmane.org>
2014-04-15 6:41 ` [PATCH 1/7] gpiolib: gpiolib-of: Implement device tree gpio-names based lookup Chen-Yu Tsai
[not found] ` <1397544101-18135-2-git-send-email-wens-jdAy2FN1RRM@public.gmane.org>
2014-04-15 14:20 ` Maxime Ripard
2014-04-16 6:12 ` Alexandre Courbot
[not found] ` <CAAVeFuLDhTVGDnmYtnxEY8hhn6HE6tU9OB24WDPtmxEHjiRiuQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-16 7:06 ` Alexandre Courbot
[not found] ` <CAAVeFu+rJXH=Uat5_qWPu6OfmDAFxHj2b+n=OSmwtSw4s+fv6w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-16 9:56 ` Chen-Yu Tsai
2014-04-22 15:02 ` Linus Walleij
[not found] ` <CACRpkdZDjC1KxM2yJqsgpg2MxBamX1EObsuahB-2c+ShuBXm8A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-23 1:49 ` Alexandre Courbot
[not found] ` <CAAVeFuL7B7kVw7ME=Vo_snhG27aBphKO8Uzvzen1gyD=R2ETNA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-28 16:19 ` Chen-Yu Tsai
2014-04-15 6:41 ` [PATCH 2/7] gpiolib: Support purely name based gpiod lookup in device trees Chen-Yu Tsai
[not found] ` <1397544101-18135-3-git-send-email-wens-jdAy2FN1RRM@public.gmane.org>
2014-04-22 15:00 ` Linus Walleij
[not found] ` <CACRpkdZ+3dnhoj1TS4KSVUP8iFHsjjwop-FG2Nf07YtH6aSO_Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-22 15:18 ` Maxime Ripard
2014-04-23 13:55 ` Linus Walleij
2014-04-15 6:41 ` [PATCH 3/7] net: rfkill: gpio: use clk_prepare_enable/clk_disable_unprepare Chen-Yu Tsai
2014-04-15 14:26 ` Maxime Ripard
2014-04-15 6:41 ` [PATCH 4/7] net: rfkill: gpio: fix reversed clock enable state Chen-Yu Tsai
[not found] ` <1397544101-18135-5-git-send-email-wens-jdAy2FN1RRM@public.gmane.org>
2014-04-15 14:27 ` Maxime Ripard
2014-04-15 6:41 ` [PATCH 5/7] net: rfkill: gpio: add device tree support Chen-Yu Tsai
2014-04-15 21:00 ` Stephen Warren
2014-04-15 21:01 ` Stephen Warren
2014-04-15 6:41 ` [PATCH 6/7] net: rfkill: gpio: add clock-frequency device tree property Chen-Yu Tsai
[not found] ` <1397544101-18135-7-git-send-email-wens-jdAy2FN1RRM@public.gmane.org>
2014-04-15 14:44 ` Maxime Ripard
2014-04-15 6:41 ` [PATCH 7/7] ARM: sun7i: cubietruck: enable bluetooth module Chen-Yu Tsai
[not found] ` <1397544101-18135-8-git-send-email-wens-jdAy2FN1RRM@public.gmane.org>
2014-04-15 14:42 ` Maxime Ripard
2014-04-15 16:06 ` Chen-Yu Tsai
2014-04-15 16:18 ` [linux-sunxi] " One Thousand Gnomes
[not found] ` <CAGb2v643HyvFdhQ0znreB8ENXHWpcx6tFwdeU7VuU8KYWcT4ZA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-16 9:44 ` Maxime Ripard
2014-04-16 10:39 ` Chen-Yu Tsai
[not found] ` <CAGb2v67HzB22a3huRRZyufXkdTFE410MhXqAHyC-MmVo0-GCFA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-16 13:09 ` Hans de Goede [this message]
[not found] ` <534E8102.4070404-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-04-17 7:43 ` Arend van Spriel
[not found] ` <534F862C.8010604-dY08KVG/lbpWk0Htik3J/w@public.gmane.org>
2014-04-18 17:49 ` maxime.ripard
2014-04-18 17:47 ` maxime.ripard
2014-04-16 13:08 ` Hans de Goede
2014-04-22 15:06 ` [PATCH 0/7] net: rfkill: gpio: Add device tree support Johannes Berg
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