Messages in this thread | | | Date | Thu, 14 May 2020 18:18:31 +0530 | From | Manivannan Sadhasivam <> | Subject | Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver |
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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
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