From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "Kieran Bingham" <kieran.bingham+renesas@ideasonboard.com>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
"Linux Media Mailing List" <linux-media@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Mauro Carvalho Chehab" <mchehab@kernel.org>,
"Kieran Bingham" <kieran.bingham@ideasonboard.com>,
"Laurent Pinchart" <laurent.pinchart@ideasonboard.com>,
"Jacopo Mondi" <jacopo@jmondi.org>,
"Niklas Söderlund" <niklas.soderlund@ragnatech.se>,
"Sakari Ailus" <sakari.ailus@iki.fi>,
"Hans Verkuil" <hverkuil@xs4all.nl>,
"Hyun Kwon" <hyunk@xilinx.com>,
"Rob Herring" <robh+dt@kernel.org>,
"Jacopo Mondi" <jacopo+renesas@jmondi.org>,
"Laurent Pinchart" <laurent.pinchart+renesas@ideasonboard.com>,
"Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>
Subject: Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver
Date: Thu, 14 May 2020 18:18:31 +0530 [thread overview]
Message-ID: <20200514124831.GG2877@Mani-XPS-13-9360> (raw)
In-Reply-To: <CAMuHMdWSEY2q1f1iobrSXHYWzweV9yjk4i1ROj2Yde7DJMiabQ@mail.gmail.com>
On Thu, May 14, 2020 at 01:59:35PM +0200, Geert Uytterhoeven wrote:
> Hi Kieran,
>
> On Thu, May 14, 2020 at 1:47 PM Kieran Bingham
> <kieran.bingham+renesas@ideasonboard.com> wrote:
> > On 14/05/2020 11:13, Manivannan Sadhasivam wrote:
> > > On Thu, May 14, 2020 at 11:02:53AM +0100, Kieran Bingham wrote:
> > >> On 12/05/2020 19:17, Manivannan Sadhasivam wrote:
> > >>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> > >>>> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
> > >>>> CSI-2 output. The device supports multicamera streaming applications,
> > >>>> and features the ability to synchronise the attached cameras.
> > >>>>
> > >>>> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
> > >>>> is supported over I2C, which implements an I2C mux to facilitate
> > >>>> communications with connected cameras across the reverse control
> > >>>> channel.
> > >>>>
> > >>>> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > >>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > >>>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > >>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>
> > >>>> --- /dev/null
> > >>>> +++ b/drivers/media/i2c/max9286.c
>
> > >>>> +static int max9286_register_gpio(struct max9286_priv *priv)
> > >>>> +{
> > >>>> + struct device *dev = &priv->client->dev;
> > >>>> + struct gpio_chip *gpio = &priv->gpio;
> > >>>> + int ret;
> > >>>> +
> > >>>> + static const char * const names[] = {
> > >>>> + "GPIO0OUT",
> > >>>> + "GPIO1OUT",
> > >>>> + };
> > >>>> +
> > >>>> + /* Configure the GPIO */
> > >>>> + gpio->label = dev_name(dev);
> > >>>
> > >>> So if you have more than one MAX9286 in a system, all gpiochips will appear
> > >>> with the same name. I'd recommend to append the index to distinguish properly.
> > >>
> > >> Ah yes, that's a good point, and I think I've even seen that.
> > >>
> > >> I'll fix it now.
> >
> > Oh, in fact actually this doesn't.
> >
> > gpiodetect prints:
> >
> > gpiochip10 [4-004c] (2 lines)
> > gpiochip11 [4-006c] (2 lines)
> >
> > and mostly references them as gpiochip10 and gpiochip11.
>
> Indeed, dev_name() should be different for each instance.
>
Ah, my bad! Somehow I got confused that this delivers static name... Sorry for
the noise, Kieran.
> > However,
> >
> > > [ 2.318533] gpio gpiochip11: Detected name collision for GPIO name 'GPIO0OUT'
> > > [ 2.325739] gpio gpiochip11: Detected name collision for GPIO name 'GPIO1OUT'
> >
> > That seems to be more of a problem for the gpio library, so I think I'll
> > just drop the const names. I don't think they add much value.
>
Well, I should've pointed this instead of above...
(lack of coffee)
> These are the line names. If they're not unique, a warning is printed,
> but they are still registered.
> So probably you want to use kasprintf("%s.%s", dev_name(dev), names[i]) to
> generate names.
>
Ack.
I think you should CC Linus W for next iteration to get review for gpiolib
implementation.
Thanks,
Mani
> See "[PATCH] gpiolib: Document that GPIO line names are not globally unique"
> (https://lore.kernel.org/linux-gpio/20200511101828.30046-1-geert+renesas@glider.be/)
> to clear up the details.
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
next prev parent reply other threads:[~2020-05-14 12:48 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-12 15:51 [PATCH v9 0/4] MAX9286 GMSL Support (+RDACM20) Kieran Bingham
2020-05-12 15:51 ` [PATCH v9 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286 Kieran Bingham
2020-05-12 22:33 ` Rob Herring
2020-05-13 12:54 ` Jacopo Mondi
2020-05-14 9:43 ` [PATCH] fixup! dt-bindings: media: i2c: Add bindings for Maxima Integrated MAX9286 Kieran Bingham
2020-05-14 10:20 ` Jacopo Mondi
2020-05-12 22:36 ` [PATCH v9 1/4] dt-bindings: media: i2c: Add bindings for Maxim " Rob Herring
2020-05-13 12:28 ` Jacopo Mondi
2020-05-12 15:51 ` [PATCH v9 2/4] media: i2c: Add MAX9286 driver Kieran Bingham
2020-05-12 17:40 ` Manivannan Sadhasivam
2020-05-14 9:53 ` Kieran Bingham
2020-05-14 9:59 ` Manivannan Sadhasivam
2020-05-14 10:05 ` Kieran Bingham
2020-05-12 18:17 ` Manivannan Sadhasivam
2020-05-14 10:02 ` Kieran Bingham
2020-05-14 10:13 ` Manivannan Sadhasivam
2020-05-14 11:47 ` Kieran Bingham
2020-05-14 11:59 ` Geert Uytterhoeven
2020-05-14 12:48 ` Manivannan Sadhasivam [this message]
2020-05-14 13:50 ` Kieran Bingham
2020-05-14 11:47 ` Kieran Bingham
2020-05-14 12:27 ` Kieran Bingham
2020-05-14 12:54 ` Manivannan Sadhasivam
2020-05-16 21:51 ` Sakari Ailus
2020-05-18 11:45 ` Kieran Bingham
2020-05-18 12:38 ` Jacopo Mondi
2020-05-18 13:09 ` Kieran Bingham
2020-05-18 16:11 ` [PATCH] fixes! [max9286]: Validate link formats Kieran Bingham
2020-05-18 18:44 ` Kieran Bingham
2020-05-19 8:13 ` Sakari Ailus
2020-05-19 7:56 ` Jacopo Mondi
2020-05-19 9:00 ` Kieran Bingham
2020-05-19 8:10 ` [PATCH v9 2/4] media: i2c: Add MAX9286 driver Sakari Ailus
2020-05-19 8:55 ` Kieran Bingham
2020-05-19 9:03 ` Sakari Ailus
2020-05-20 0:50 ` Laurent Pinchart
2020-05-26 8:54 ` Sakari Ailus
2020-05-12 15:51 ` [PATCH v9 3/4] dt-bindings: media: i2c: Add bindings for IMI RDACM2x Kieran Bingham
2020-05-12 15:51 ` [PATCH v9 4/4] media: i2c: Add RDACM20 driver Kieran Bingham
2020-05-16 22:36 ` Sakari Ailus
2020-05-18 7:35 ` Jacopo Mondi
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