From: Daniel Scally <djrscally@gmail.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
linux-i2c <linux-i2c@vger.kernel.org>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
devel@acpica.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Wolfram Sang <wsa@kernel.org>, Yong Zhi <yong.zhi@intel.com>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
Bingbu Cao <bingbu.cao@intel.com>,
Tian Shu Qiu <tian.shu.qiu@intel.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Robert Moore <robert.moore@intel.com>,
Erik Kaneda <erik.kaneda@intel.com>,
Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
kieran.bingham+renesas@ideasonboard.com,
Jacopo Mondi <jacopo+renesas@jmondi.org>,
Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
Jordan Hand <jorhand@linux.microsoft.com>,
Tsuchiya Yuto <kitakar@gmail.com>,
"Krogerus, Heikki" <heikki.krogerus@linux.intel.com>
Subject: Re: [PATCH 18/18] ipu3: Add driver for dummy INT3472 ACPI device
Date: Sat, 9 Jan 2021 00:39:45 +0000 [thread overview]
Message-ID: <7f20c116-a3fc-9374-aaf2-4cf57a9a07f9@gmail.com> (raw)
In-Reply-To: <X/j2OnQpuJRLw3DP@pendragon.ideasonboard.com>
Hi Laurent
On 09/01/2021 00:18, Laurent Pinchart wrote:
> H Andy and Daniel,
>
> On Fri, Jan 08, 2021 at 02:17:49PM +0200, Andy Shevchenko wrote:
>> On Fri, Jan 8, 2021 at 1:56 AM Daniel Scally wrote:
>>> On 30/11/2020 20:07, Andy Shevchenko wrote:
>>>> On Mon, Nov 30, 2020 at 01:31:29PM +0000, Daniel Scally wrote:
>> ...
>>
>>>> It's solely Windows driver design...
>>>> Luckily I found some information and can clarify above table:
>>>>
>>>> 0x00 Reset
>>>> 0x01 Power down
>>>> 0x0b Power enable
>>>> 0x0c Clock enable
>>>> 0x0d LED (active high)
>>>>
>>>> The above text perhaps should go somewhere under Documentation.
>>> Coming back to this; there's a bit of an anomaly with the 0x01 Power
>>> Down pin for at least one platform. As listed above, the OV2680 on one
>>> of my platforms has 3 GPIOs defined, and the table above gives them as
>>> type Reset, Power down and Clock enable. I'd assumed from this table
>>> that "power down" meant a powerdown GPIO (I.E. the one usually called
>>> PWDNB in Omnivision datasheets and "powerdown" in drivers), but the
>>> datasheet for the OV2680 doesn't list a separate reset and powerdown
>>> pin, but rather a single pin that performs both functions.
> First question, do we have a confirmation that the OV2680 sensor on that
> platform requires GPIO 0x01 to be toggled to work properly ?
Yes; without that toggled not even the i2c interface is available.
> I'd like to
> rule out the option of the GPIO being simply not connected (that would
> be best for us, although my experience so far with this terrible ACPI
> design doesn't of course give me much hope).
Sorry to dash what little hope was left.
> Where did you find the OV2680 datasheet by the way, can you share a link
> to a leaked version ?
Sure. I left the PC already, but I'll do that tomorrow.
>> All of them are GPIOs, the question here is how they are actually
>> connected on PCB level and I have no answer to that. You have to find
>> schematics somewhere.
>>
>>> Am I wrong to treat that as something that ought to be mapped as a
>>> powerdown GPIO to the sensors? Or do you know of any other way to
>>> reconcile that discrepancy?
>> The GPIOs can go directly to the sensors or be a control pin for
>> separate discrete power gates.
> GPIO functions 0x00 and 0x01 are meant to control sensor signals, while
> GPIO function 0x0b is meant to control a power gate. Of course board
> designers may have thought clever to use function 0x01 to control a
> second power gate, this can't be ruled out without the schematics (or
> reverse engineering of the hardware).
>
>> So, we can do one of the following:
>> a) present PD GPIO as fixed regulator;
>> b) present PD & Reset GPIOs as regulator;
>> c) provide them as is to the sensor and sensor driver must do what it
>> considers right.
>>
>> Since we don't have schematics (yet?) and we have plenty of variations
>> of sensors, I would go to c) and update the driver of the affected
>> sensor as needed. Because even if you have separate discrete PD for
>> one sensor on one platform there is no guarantee that it will be the
>> same on another. Providing a "virtual" PD in a sensor that doesn't
>> support it is the best choice I think. Let's hear what Sakari and
>> other experienced camera sensor developers say.
>>
>> My vision is purely based on electrical engineering background,
>> experience with existing (not exactly camera) sensor drivers and
>> generic cases.
> If the OV2680 has indeed no power down pin, that won't work. Adding
> support for a non-existent powerdown pin to the corresponding driver
> won't be accepted. Workarounds and hacks to support IPU3-based devices
> need to be kept out of camera sensor drivers.
>
> If we need to map GPIO function 0x01 to a sensor GPIO on some platform,
> and to a regulator on other platforms, then we will need per-platform
> data in the INT3472 driver. For this particular platform, the reset
> (0x00) GPIO should be passed to the sensor, and the powerdown (0x01)
> GPIO should control a regulator (again assuming that our assumption that
> the GPIO is wired to a power gate is correct).
Let me think of a neat way to do this then.
>
>>> Failing that; the only way I can think to handle this is to register
>>> proxy GPIO pins assigned to the sensors as you suggested previously, and
>>> have them toggle the GPIO's assigned to the INT3472 based on platform
>>> specific mapping data (I.E. we register a pin called "reset", which on
>>> most platforms just toggles the 0x00 pin, but on this specific platform
>>> would drive both 0x00 and 0x01 together. We're already heading that way
>>> for the regulator consumer supplies so it's sort of nothing new, but I'd
>>> still rather not if it can be avoided.
next prev parent reply other threads:[~2021-01-09 0:40 UTC|newest]
Thread overview: 144+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-30 13:31 [PATCH 00/18] Add functionality to ipu3-cio2 driver allowing software_node connections to sensors on platforms designed for Windows Daniel Scally
2020-11-30 13:31 ` [PATCH 01/18] property: Return true in fwnode_device_is_available for node types that do not implement this operation Daniel Scally
2020-11-30 16:05 ` Laurent Pinchart
2020-11-30 17:21 ` Andy Shevchenko
2020-12-01 3:12 ` Bingbu Cao
2020-12-01 8:46 ` Dan Scally
2020-11-30 13:31 ` [PATCH 02/18] property: Add support for calling fwnode_graph_get_endpoint_by_id() for fwnode->secondary Daniel Scally
2020-11-30 16:08 ` Laurent Pinchart
2020-11-30 17:29 ` Andy Shevchenko
2020-11-30 17:28 ` Laurent Pinchart
2020-11-30 17:53 ` Andy Shevchenko
2020-11-30 18:41 ` Laurent Pinchart
2020-11-30 19:21 ` Andy Shevchenko
2020-12-02 10:13 ` Dan Scally
2020-11-30 13:31 ` [PATCH 03/18] software_node: Fix failure to put() and get() references to children in software_node_get_next_child() Daniel Scally
2020-11-30 16:10 ` Laurent Pinchart
2020-11-30 17:30 ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 04/18] software_node: Enforce parent before child ordering of nodes array for software_node_register_nodes() Daniel Scally
2020-11-30 16:11 ` Laurent Pinchart
2020-11-30 16:12 ` Laurent Pinchart
2020-11-30 23:10 ` Dan Scally
2020-11-30 17:35 ` Andy Shevchenko
2020-11-30 17:37 ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 05/18] software_node: Alter software_node_unregister_nodes() to unregister the array in reverse order Daniel Scally
2020-11-30 16:14 ` Laurent Pinchart
2020-11-30 17:45 ` Andy Shevchenko
2020-12-01 23:36 ` Dan Scally
2020-11-30 13:31 ` [PATCH 06/18] software_node: amend software_node_unregister_node_group() to perform unregistration of array in reverse order to be consistent with software_node_unregister_nodes() Daniel Scally
2020-11-30 16:17 ` Laurent Pinchart
2020-11-30 17:47 ` Andy Shevchenko
2020-12-02 10:04 ` Dan Scally
2020-11-30 17:19 ` kernel test robot
2020-12-01 18:18 ` Dan Carpenter
2020-11-30 13:31 ` [PATCH 07/18] software_node: Add support for fwnode_graph*() family of functions Daniel Scally
2020-11-30 16:25 ` Laurent Pinchart
2020-11-30 23:34 ` Dan Scally
2020-11-30 13:31 ` [PATCH 08/18] lib/test_printf.c: Use helper function to unwind array of software_nodes Daniel Scally
2020-11-30 15:54 ` Sergey Senozhatsky
2020-11-30 16:26 ` Laurent Pinchart
2020-11-30 13:31 ` [PATCH 09/18] ipu3-cio2: Add T: entry to MAINTAINERS Daniel Scally
2020-11-30 13:31 ` [PATCH 10/18] ipu3-cio2: Rename ipu3-cio2.c to allow module to be built from multiple source files retaining ipu3-cio2 name Daniel Scally
2020-12-01 6:56 ` Bingbu Cao
2020-12-01 7:07 ` Bingbu Cao
2020-11-30 13:31 ` [PATCH 11/18] media: v4l2-core: v4l2-async: Check possible match in match_fwnode based on sd->fwnode->secondary Daniel Scally
2020-11-30 16:27 ` Laurent Pinchart
2020-11-30 17:55 ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 12/18] acpi: Add acpi_dev_get_next_match_dev() and macro to iterate through acpi_devices matching a given _HID Daniel Scally
2020-11-30 17:58 ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 13/18] ipu3-cio2: Add functionality allowing software_node connections to sensors on platforms designed for Windows Daniel Scally
2020-11-30 16:45 ` kernel test robot
2020-11-30 17:09 ` Laurent Pinchart
2020-11-30 18:14 ` Andy Shevchenko
2020-12-01 22:08 ` Dan Scally
2020-12-01 22:11 ` Dan Scally
2020-12-01 22:30 ` Laurent Pinchart
2020-12-01 23:15 ` Dan Scally
2020-12-02 10:38 ` Sakari Ailus
2020-12-02 10:53 ` Dan Scally
2020-12-02 12:02 ` Andy Shevchenko
2020-12-02 22:44 ` Dan Scally
2020-12-02 12:01 ` Andy Shevchenko
2020-11-30 20:27 ` kernel test robot
2020-11-30 20:35 ` Sakari Ailus
2020-12-01 8:13 ` Dan Scally
2020-12-01 15:06 ` Andy Shevchenko
2020-12-15 10:28 ` Daniel Scally
2020-12-15 10:32 ` Daniel Scally
2020-12-15 22:02 ` Sakari Ailus
2020-12-17 14:17 ` Daniel Scally
2020-11-30 13:31 ` [PATCH 14/18] acpi: utils: Add function to fetch dependent acpi_devices Daniel Scally
2020-11-30 18:23 ` Andy Shevchenko
2020-11-30 18:40 ` Laurent Pinchart
2020-11-30 23:54 ` Dan Scally
2020-12-01 15:10 ` Andy Shevchenko
2020-12-01 15:23 ` Dan Scally
2020-11-30 13:31 ` [PATCH 15/18] i2c: i2c-core-acpi: Add i2c_acpi_dev_name() Daniel Scally
2020-11-30 17:11 ` Laurent Pinchart
2020-12-02 22:44 ` Dan Scally
2020-11-30 13:31 ` [PATCH 16/18] i2c: i2c-core-base: Use the new i2c_acpi_dev_name() in i2c_set_dev_name() Daniel Scally
2020-11-30 17:12 ` Laurent Pinchart
2020-11-30 19:18 ` Andy Shevchenko
2020-12-02 9:35 ` Andy Shevchenko
2020-12-02 9:49 ` Dan Scally
2020-12-01 23:50 ` Dan Scally
2020-11-30 13:31 ` [PATCH 17/18] gpio: gpiolib-acpi: Export acpi_get_gpiod() Daniel Scally
2020-11-30 17:02 ` kernel test robot
2020-11-30 18:04 ` kernel test robot
2020-11-30 19:20 ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 18/18] ipu3: Add driver for dummy INT3472 ACPI device Daniel Scally
2020-11-30 16:17 ` Jean-Michel Hautbois
2020-11-30 23:20 ` Dan Scally
2020-12-01 18:31 ` Andy Shevchenko
2020-12-01 18:36 ` Laurent Pinchart
2020-12-01 18:51 ` Andy Shevchenko
2020-11-30 16:29 ` Kieran Bingham
2020-11-30 17:21 ` Laurent Pinchart
2020-11-30 20:07 ` Andy Shevchenko
2020-11-30 23:32 ` Laurent Pinchart
2020-12-01 15:55 ` Sakari Ailus
2020-12-01 18:37 ` Laurent Pinchart
2020-12-02 11:09 ` Sakari Ailus
2020-12-02 12:42 ` Laurent Pinchart
2020-12-02 15:08 ` Andy Shevchenko
2020-12-03 12:37 ` Dan Scally
2020-12-03 12:57 ` Andy Shevchenko
2020-12-01 18:49 ` Andy Shevchenko
2020-12-01 20:59 ` Dan Scally
2020-12-02 9:39 ` Andy Shevchenko
2020-12-02 12:35 ` Laurent Pinchart
2020-12-02 15:11 ` Andy Shevchenko
2020-12-03 12:25 ` Dan Scally
2020-12-13 22:48 ` Daniel Scally
2020-12-14 15:33 ` Andy Shevchenko
2020-12-01 8:30 ` Dan Scally
2020-12-01 18:54 ` Andy Shevchenko
2020-12-01 18:55 ` Laurent Pinchart
2020-12-01 19:05 ` Andy Shevchenko
2020-12-01 19:06 ` Laurent Pinchart
2020-12-01 19:21 ` Andy Shevchenko
2020-12-01 20:34 ` Hans de Goede
2020-12-01 20:46 ` Andy Shevchenko
2020-12-02 12:48 ` Laurent Pinchart
2020-12-02 15:15 ` Andy Shevchenko
2020-12-01 21:05 ` Dan Scally
2020-12-02 9:42 ` Andy Shevchenko
2021-01-07 23:55 ` Daniel Scally
2021-01-08 12:17 ` Andy Shevchenko
2021-01-08 23:24 ` Daniel Scally
[not found] ` <CAHp75Vcy878xKUUUDH5ory9uS-Vhhx_W1PZc=S6hsSLYJ0i60w@mail.gmail.com>
2021-01-09 9:58 ` Daniel Scally
2021-01-09 0:18 ` Laurent Pinchart
2021-01-09 0:39 ` Daniel Scally [this message]
2020-11-30 20:52 ` Sakari Ailus
2020-11-30 23:06 ` Dan Scally
2020-11-30 23:21 ` Laurent Pinchart
2020-12-01 0:05 ` Dan Scally
2020-12-01 6:44 ` Sakari Ailus
2020-12-01 8:08 ` Dan Scally
2020-12-01 8:09 ` Dan Scally
2020-12-01 12:32 ` Sakari Ailus
2020-12-01 12:40 ` Laurent Pinchart
2020-12-01 12:44 ` Sakari Ailus
2020-12-01 12:48 ` Dan Scally
2020-12-01 19:01 ` Andy Shevchenko
2020-12-01 18:55 ` Andy Shevchenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7f20c116-a3fc-9374-aaf2-4cf57a9a07f9@gmail.com \
--to=djrscally@gmail.com \
--cc=andriy.shevchenko@linux.intel.com \
--cc=andy.shevchenko@gmail.com \
--cc=bgolaszewski@baylibre.com \
--cc=bingbu.cao@intel.com \
--cc=devel@acpica.org \
--cc=erik.kaneda@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=heikki.krogerus@linux.intel.com \
--cc=jacopo+renesas@jmondi.org \
--cc=jorhand@linux.microsoft.com \
--cc=kieran.bingham+renesas@ideasonboard.com \
--cc=kitakar@gmail.com \
--cc=laurent.pinchart+renesas@ideasonboard.com \
--cc=laurent.pinchart@ideasonboard.com \
--cc=lenb@kernel.org \
--cc=linus.walleij@linaro.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=mchehab@kernel.org \
--cc=mika.westerberg@linux.intel.com \
--cc=pmladek@suse.com \
--cc=rjw@rjwysocki.net \
--cc=robert.moore@intel.com \
--cc=rostedt@goodmis.org \
--cc=sakari.ailus@linux.intel.com \
--cc=sergey.senozhatsky@gmail.com \
--cc=tian.shu.qiu@intel.com \
--cc=wsa@kernel.org \
--cc=yong.zhi@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).