Re: [PATCH] power_supply: Add driver for TWL4030/TPS65950 BCI charger

From: Grazvydas Ignotas <notasas@gmail.com>
To: felipe.balbi@nokia.com
Cc: ext Anton Vorontsov <avorontsov@ru.mvista.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Madhusudhan Chikkature <madhu.cr@ti.com>,
	"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>
Subject: Re: [PATCH] power_supply: Add driver for TWL4030/TPS65950 BCI charger
Date: Thu, 10 Dec 2009 22:51:06 +0200	[thread overview]
Message-ID: <6ed0b2680912101251jeec28e6i216dfc51caab13aa@mail.gmail.com> (raw)
In-Reply-To: <20091210165106.GA21502@nokia.com>

On Thu, Dec 10, 2009 at 6:51 PM, Felipe Balbi <felipe.balbi@nokia.com> wrote:
> Hi,
>
> On Thu, Dec 10, 2009 at 03:44:11PM +0100, ext Anton Vorontsov wrote:
>>
>> Yep. The only thing I'm afraid of is that once the driver is in,
>> then nobody will bother with improving it to do the right thing.
>> But an imperfect driver is better than none.
>
> I'm currently implementing the notifier part in a generic manner that would
> handle all transceivers (well, they would have to provide a some
> implementations for function pointers in struct otg_transceiver).
>
> Then drivers like twl4030-bci and musb_hdrc could register for notifications
> from the transceiver. I was thinking of notifying the following events:
>
> enum usb_xceiv_events {
>        USB_EVENT_NONE,         /* no events or cable disconnected */
>        USB_EVENT_VBUS,         /* vbus valid event */
>        USB_EVENT_ID,           /* id was grounded */
>        USB_EVENT_CHARGER,      /* usb dedicated charger */
>        USB_EVENT_ENUMERATED,   /* gadget driver enumerated */
> };
>
> for the USB_EVENT_ENUMERATED we could also pass the bMaxPower (in mA) field
> of the struct usb_configuration, then BCI (or bq24xxx for that matter) can
> configure that as input current for charging.
>
> USB_EVENT_ID is necessary because in most boards (at least the ones I've
> seen) the charging chip (bq24xxx) also plays the role as charge pump,
> sourcing vbus on OTG sessions.
>
> USB_EVENT_VBUS and USB_EVENT_CHARGER aren't necessary on all cases, but
> boards like RX-51 where it has a different transceiver for charger
> detection, it's necessary to have those two separated.
>
> If you guys have any comments already, please comment :-)
>
> I'll try to finish a prototype by tomorrow and try to send it as RFC.

Nice! Looking good, it seems this has everything BCI needs, will wait
for your code before updating BCI.