From: Guenter Roeck <linux@roeck-us.net>
To: Mats Karrman <mats.dev.list@gmail.com>,
Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
Felipe Balbi <felipe.balbi@linux.intel.com>,
Oliver Neukum <oneukum@suse.com>,
linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: [PATCH v17 2/3] usb: USB Type-C connector class
Date: Fri, 10 Mar 2017 15:41:08 -0800 [thread overview]
Message-ID: <ce0350a4-f7d9-3fdd-88ee-8cb827ecee2a@roeck-us.net> (raw)
In-Reply-To: <68817c44-d880-581a-e9f5-12845b9215eb@gmail.com>
On 03/10/2017 02:22 PM, Mats Karrman wrote:
> On 2017-03-08 14:58, Heikki Krogerus wrote:
>
>> On Tue, Mar 07, 2017 at 11:30:54PM +0100, Mats Karrman wrote:
>>> If I read Heikki's original suggestion I understand it like the DP driver would be
>>> responsible for AM specific USB PD/VDM communication. But wouldn't that lead
>>> to a lot of code duplication since the AM protocol is the same for all drivers of
>>> a kind?
>> No that's not what I mean. I'm still mixing your PD controller with
>> something else above, sorry about that. Your PD controller driver
>> should not ideally even need to be aware of Type-C connector, right?
>> It definitely does not need to do any USB PD communication.
>
> Right.
>
>> I would imagine you have on top of the DP controller, a mux (which
>> could be a DP/USB3 PHY like on Rockchip RK3399, discrete mux like
>> Pericom PI3USB30532, or something else), and a USB Type-C PHY or USB
>> PD controller. The bus would be tying the mux to the Type-C port (PHY
>> or PD controller) and its partner (note that it does not tie the mux
>> to the DP controller). Please correct me if I'm wrong about your
>> hardware.
>
> No, you're correct, a discrete mux and a fusb302.
>
>> Assuming that is how your board roughly looks like, the driver for the
>> mux would be the driver for the DP altmode devices. That driver would
>> be the one converting things like the Attention messages notifying
>> about HPD into toggling of GPIOs, or what ever is needed on your
>> board, etc.
>
> OK.
>
>> The actual PD communication with VDMs should be considered as just the
>> protocol, so we probable should have "protocol drivers". For example
>> DP alternate mode VDMs and communication will always be the same
>> despite of the hardware. The DP alternate mode "protocol driver" would
>> then be tied to the alternate mode device for the partner, and that
>> driver could have its own hooks for what ever is needed, like HPD
>> signal handling, configuration changes, whatever. In any case,
>> hopefully making things easy and straightforward for the "mux driver",
>> _so that it does not need to care about the actual PD communication_.
>
> I'm digesting your and Guenter's replies and patches.
> I will try getting something up and running too soon and hopefully the foggy parts will
> dissolve. As for now I find it a lot easier to grok Guenter's drivers than to see the
> advantages and/or disadvantages of an altmode bus :-)
>
> @Guenter: There _is_ interest for your fusb302 driver, thank you
>
Ok, I'll see what I need to do to publish it.
Guenter
next prev parent reply other threads:[~2017-03-10 23:41 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-21 14:24 [PATCH v17 0/3] USB Type-C Connector class Heikki Krogerus
2017-02-21 14:24 ` [PATCH v17 1/3] lib/string: add sysfs_match_string helper Heikki Krogerus
2017-02-21 14:24 ` [PATCH v17 2/3] usb: USB Type-C connector class Heikki Krogerus
2017-03-02 15:22 ` Mats Karrman
2017-03-03 3:13 ` Guenter Roeck
2017-03-03 7:29 ` Mats Karrman
2017-03-03 9:48 ` Enric Balletbo Serra
2017-03-03 12:59 ` Heikki Krogerus
2017-03-03 14:49 ` Guenter Roeck
2017-03-03 19:27 ` Mats Karrman
2017-03-06 9:37 ` Oliver Neukum
2017-03-06 13:14 ` Heikki Krogerus
2017-03-07 22:30 ` Mats Karrman
2017-03-08 1:38 ` Guenter Roeck
2017-04-08 23:09 ` USB Type-C Port Manager API concern Mats Karrman
2017-04-09 15:16 ` Guenter Roeck
2017-04-09 21:05 ` Mats Karrman
2017-04-14 2:57 ` Guenter Roeck
2017-04-14 8:30 ` Mats Karrman
2017-03-08 13:58 ` [PATCH v17 2/3] usb: USB Type-C connector class Heikki Krogerus
2017-03-10 22:22 ` Mats Karrman
2017-03-10 23:41 ` Guenter Roeck [this message]
2017-04-18 18:52 ` Badhri Jagan Sridharan
2017-04-19 11:23 ` Heikki Krogerus
2017-04-19 14:45 ` Badhri Jagan Sridharan
2017-04-19 15:14 ` Guenter Roeck
2017-04-19 17:22 ` Badhri Jagan Sridharan
2017-04-19 19:29 ` Guenter Roeck
2017-04-20 12:24 ` Heikki Krogerus
2017-04-20 19:46 ` Badhri Jagan Sridharan
2017-04-21 12:12 ` Heikki Krogerus
2017-04-21 13:14 ` Guenter Roeck
2017-04-21 14:27 ` Rajaram R
2017-04-21 16:43 ` Guenter Roeck
2017-04-22 9:23 ` Rajaram R
2017-04-24 17:50 ` Badhri Jagan Sridharan
2017-04-25 8:26 ` Rajaram R
2017-04-25 14:10 ` Guenter Roeck
2017-04-27 6:20 ` Rajaram R
2017-04-27 18:10 ` Guenter Roeck
2017-04-28 10:52 ` Heikki Krogerus
2017-04-20 11:55 ` Heikki Krogerus
2017-03-03 14:41 ` Guenter Roeck
2017-03-03 3:35 ` Peter Chen
2017-03-03 4:29 ` Guenter Roeck
2017-03-03 4:52 ` Peter Chen
2017-03-03 14:36 ` Guenter Roeck
2017-03-06 1:24 ` Peter Chen
2017-03-03 14:31 ` Heikki Krogerus
2017-03-06 1:15 ` Peter Chen
2017-03-06 13:16 ` Heikki Krogerus
2017-03-07 1:36 ` Peter Chen
2017-03-07 8:57 ` Heikki Krogerus
2017-03-08 1:53 ` Guenter Roeck
2017-03-08 6:50 ` Peter Chen
2017-03-08 14:44 ` Guenter Roeck
2017-03-09 2:00 ` Peter Chen
2017-02-21 14:24 ` [PATCH v17 3/3] usb: typec: add driver for Intel Whiskey Cove PMIC USB Type-C PHY Heikki Krogerus
2017-02-21 15:42 ` [PATCH v17 0/3] USB Type-C Connector class Felipe Balbi
2017-03-21 11:14 ` Heikki Krogerus
2017-03-21 10:23 ` Greg KH
2017-03-21 10:37 ` Heikki Krogerus
2017-03-22 21:15 ` Mats Karrman
2017-03-23 8:16 ` Heikki Krogerus
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