Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756090Ab3HYAOF (ORCPT ); Sat, 24 Aug 2013 20:14:05 -0400 Received: from perceval.ideasonboard.com ([95.142.166.194]:50169 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755941Ab3HYAOD (ORCPT ); Sat, 24 Aug 2013 20:14:03 -0400 From: Laurent Pinchart To: Tomasz Figa Cc: Laurent Pinchart , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Linus Walleij , swarren@wwwdotorg.org, ian.campbell@citrix.com, mark.rutland@arm.com, pawel.moll@arm.com, galak@codeaurora.org, rob.herring@calxeda.com Subject: Re: [PATCH v2 3/3] gpio: pcf857x: Add OF support Date: Sun, 25 Aug 2013 02:15:18 +0200 Message-ID: <11480687.DR76avTJMu@avalon> User-Agent: KMail/4.10.5 (Linux/3.8.13-gentoo; KDE/4.10.5; x86_64; ; ) In-Reply-To: <2417846.CRj8QejgZy@flatron> References: <1376953494-9684-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <1688346.YLZnUtEaXr@avalon> <2417846.CRj8QejgZy@flatron> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4410 Lines: 110 Hi Tomasz, On Saturday 24 August 2013 16:13:11 Tomasz Figa wrote: > On Saturday 24 of August 2013 02:54:07 Laurent Pinchart wrote: > > On Saturday 24 August 2013 02:41:59 Tomasz Figa wrote: > > > On Tuesday 20 of August 2013 01:04:54 Laurent Pinchart wrote: > > > > Add DT bindings for the pcf857x-compatible chips and parse the > > > > device tree node in the driver. > > > > > > > > Signed-off-by: Laurent Pinchart > > > > --- > > > > > > > > .../devicetree/bindings/gpio/gpio-pcf857x.txt | 71 +++++++++++++ > > > > drivers/gpio/gpio-pcf857x.c | 57 ++++++++++--- > > > > 2 files changed, 119 insertions(+), 9 deletions(-) > > > > create mode 100644 [snip] > > > > diff --git a/drivers/gpio/gpio-pcf857x.c > > > > b/drivers/gpio/gpio-pcf857x.c > > > > index 070e81f..50a90f1 100644 > > > > --- a/drivers/gpio/gpio-pcf857x.c > > > > +++ b/drivers/gpio/gpio-pcf857x.c > > > > [snip] > > > > > > @@ -50,6 +52,27 @@ static const struct i2c_device_id pcf857x_id[] = > > > > { > > > > > > > > }; > > > > MODULE_DEVICE_TABLE(i2c, pcf857x_id); > > > > > > > > +#ifdef CONFIG_OF > > > > +static const struct of_device_id pcf857x_of_table[] = { > > > > + { .compatible = "nxp,pcf8574", .data = (void *)8 }, > > > > + { .compatible = "nxp,pcf8574a", .data = (void *)8 }, > > > > + { .compatible = "nxp,pca8574", .data = (void *)8 }, > > > > + { .compatible = "nxp,pca9670", .data = (void *)8 }, > > > > + { .compatible = "nxp,pca9672", .data = (void *)8 }, > > > > + { .compatible = "nxp,pca9674", .data = (void *)8 }, > > > > + { .compatible = "nxp,pcf8575", .data = (void *)16 }, > > > > + { .compatible = "nxp,pca8575", .data = (void *)16 }, > > > > + { .compatible = "nxp,pca9671", .data = (void *)16 }, > > > > + { .compatible = "nxp,pca9673", .data = (void *)16 }, > > > > + { .compatible = "nxp,pca9675", .data = (void *)16 }, > > > > + { .compatible = "maxim,max7328", .data = (void *)8 }, > > > > + { .compatible = "maxim,max7329", .data = (void *)8 }, > > > > + { .compatible = "ti,tca9554", .data = (void *)8 }, > > > > + { } > > > > +}; > > > > +MODULE_DEVICE_TABLE(of, pcf857x_of_table); > > > > +#endif > > > > + > > > > > > > > /* > > > > * The pcf857x, pca857x, and pca967x chips only expose one read and > > > > * one write register. Writing a "one" bit (to match the reset > > > > @@ -257,14 +280,29 @@ fail: > > > > static int pcf857x_probe(struct i2c_client *client, > > > > const struct i2c_device_id *id) > > > > { > > > > - struct pcf857x_platform_data *pdata; > > > > + struct pcf857x_platform_data *pdata = client->dev.platform_data; > > > > + struct device_node *np = client->dev.of_node; > > > struct pcf857x *gpio; > > > > + unsigned int n_latch = 0; > > > > + unsigned int ngpio; > > > > int status; > > > > > > > > - pdata = client->dev.platform_data; > > > > - if (!pdata) { > > > > +#ifdef CONFIG_OF > > > > + if (np) { > > > > > > Wouldn't if (IS_ENABLED(CONFIG_OF) && np) be sufficient here, without > > > the #ifdef? You would have to move the match table out of the #ifdef > > > in this case, though... > > > > That's the exact reason why I've used #ifdef CONFIG_OF here, I didn't > > want to add the overhead of the pcf857x_of_table when CONFIG_OF isn't > > defined. > > I'm not sure if I remember correctly, but I think there was something said > in one of discussions some time ago, that we should be moving away from > ifdef'ing such things, in favour of just having them compiled > unconditionally. There seems to be a general consensus to favor if (IS_ENABLED(CONFIG_OF)) instead of #ifdef CONFIG_OF when possible. I'm not sure what the opinion is regarding using conditional compilation to avoid compiling unnecessary data tables in. I would vote for using it (there's no need to bloat the kernel unnecessarily on non-OF platforms), but I'll conform to whatever is decided to be best. > [Adding DT maintainers on Cc for more opinions.] I'll resubmit the patch with the DT bindings documentation fixed, and will submit yet another version if I need to remove the #ifdef. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/