Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

From: Paul Bolle <pebolle@tiscali.nl>
To: Nishanth Menon <nm@ti.com>
Cc: Tony Lindgren <tony@atomide.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, linux-omap@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Lokesh Vutla <lokeshvutla@ti.com>
Subject: Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver
Date: Wed, 04 Mar 2015 23:58:46 +0100	[thread overview]
Message-ID: <1425509926.2090.56.camel@tiscali.nl> (raw)
In-Reply-To: <1425427237-11511-3-git-send-email-nm@ti.com>

Nishanth Menon schreef op di 03-03-2015 om 18:00 [-0600]:
> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> index ee9f44ad7f02..8e463d75fbb2 100644
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
>  	select PINCONF
>  	select PINMUX
>  
> +config PINCTRL_TI_IODELAY
> +	bool "TI IODelay Module pinconf driver"

This adds a boolean Kconfig symbol.

> +	depends on OF
> +	select PINCONF
> +	select GENERIC_PINCONF
> +	select REGMAP_MMIO
> +	help
> +	  Say Y here to support Texas Instruments' IODelay pinconf driver.
> +	  IODelay module is used for the DRA7 SoC family. This driver is in
> +	  addition to PINCTRL_SINGLE which controls the mux.
> +
>  config PINCTRL_TZ1090
>  	bool "Toumaz Xenif TZ1090 pin control driver"
>  	depends on SOC_TZ1090
> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> index 0475206dd600..e441cd71aedf 100644
> --- a/drivers/pinctrl/Makefile
> +++ b/drivers/pinctrl/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
>  obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
>  obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
>  obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
> +obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o

So this objectfile will either be built-in or not be built at all.

>  obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
>  obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
>  obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
> diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
> new file mode 100644
> index 000000000000..e4c6e25a781c
> --- /dev/null
> +++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
> @@ -0,0 +1,963 @@
>[...]
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/list.h>
> +#include <linux/module.h>

This is, I think, a bit of a red flag.

> +#include <linux/of_device.h>
> +#include <linux/of.h>
> +#include <linux/pinctrl/pinconf-generic.h>
> +#include <linux/pinctrl/pinconf.h>
> +#include <linux/pinctrl/pinctrl.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>

[...]

> +static const struct of_device_id ti_iodelay_of_match[] = {
> +	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
> +	{ /* Hopefully no more.. */ },
> +};
> +MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
> +
> +static struct platform_driver ti_iodelay_driver = {
> +	.probe = ti_iodelay_probe,
> +	.remove = ti_iodelay_remove,
> +	.driver = {
> +		   .owner = THIS_MODULE,

So THIS_MODULE will, basically, be NULL.

> +		   .name = DRIVER_NAME,
> +		   .of_match_table = ti_iodelay_of_match,
> +		   },
> +};
> +module_platform_driver(ti_iodelay_driver);
> +
> +MODULE_AUTHOR("Texas Instruments, Inc.");
> +MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
> +MODULE_LICENSE("GPL v2");

And these three macros will be preprocessed away.

(Perhaps there are non-modular alternatives to MODULE_DEVICE_TABLE and
module_platform_driver, but I'm not sure how those two macros actually
work.)

Paul Bolle