From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alex Courbot <acourbot@nvidia.com>
Subject: Re: [PATCH v1 3/3] gpiolib: append SFI helpers for GPIO API
Date: Fri, 6 Dec 2013 10:52:11 +0900
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References: <1386261409-13850-1-git-send-email-andriy.shevchenko@linux.intel.com> <1386261409-13850-4-git-send-email-andriy.shevchenko@linux.intel.com>
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To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>, "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>, Linus Walleij <linus.walleij@linaro.org>, Mika Westerberg <mika.westerberg@linux.intel.com>, David Cohen <david.a.cohen@intel.com>, Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>, Len Brown <lenb@kernel.org>

On 12/06/2013 01:36 AM, Andy Shevchenko wrote:
> To support some (legacy) firmwares and platforms let's make life easier for
> their customers.
>
> This patch provides a function which converts sfi_gpio_table_entry to
> gpio_desc. The use of it is integrated into GPIO library to enable generic
> access to the SFI GPIO resources.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>   drivers/gpio/Kconfig       |  4 ++++
>   drivers/gpio/Makefile      |  1 +
>   drivers/gpio/gpiolib-sfi.c | 28 ++++++++++++++++++++++++++++
>   drivers/gpio/gpiolib.c     |  3 +++
>   drivers/gpio/gpiolib.h     | 13 +++++++++++++
>   5 files changed, 49 insertions(+)
>   create mode 100644 drivers/gpio/gpiolib-sfi.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index ae3682d..a12752a 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -51,6 +51,10 @@ config OF_GPIO
>   	def_bool y
>   	depends on OF
>
> +config GPIO_SFI
> +	def_bool y
> +	depends on SFI
> +
>   config GPIO_ACPI
>   	def_bool y
>   	depends on ACPI
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index ee95154..5373e3a 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -5,6 +5,7 @@ ccflags-$(CONFIG_DEBUG_GPIO)	+= -DDEBUG
>   obj-$(CONFIG_GPIO_DEVRES)	+= devres.o
>   obj-$(CONFIG_GPIOLIB)		+= gpiolib.o
>   obj-$(CONFIG_OF_GPIO)		+= gpiolib-of.o
> +obj-$(CONFIG_GPIO_SFI)		+= gpiolib-sfi.o
>   obj-$(CONFIG_GPIO_ACPI)		+= gpiolib-acpi.o
>
>   # Device drivers. Generally keep list sorted alphabetically
> diff --git a/drivers/gpio/gpiolib-sfi.c b/drivers/gpio/gpiolib-sfi.c
> new file mode 100644
> index 0000000..c804314
> --- /dev/null
> +++ b/drivers/gpio/gpiolib-sfi.c
> @@ -0,0 +1,28 @@
> +/*
> + * Simple Firmware Interface (SFI) helpers for GPIO API
> + *
> + * Copyright (C) 2013, Intel Corporation
> + * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/sfi.h>
> +#include <linux/errno.h>
> +#include <linux/err.h>
> +
> +#include "gpiolib.h"
> +
> +struct gpio_desc *sfi_get_gpiod_by_name(const char *name)
> +{
> +	struct sfi_gpio_table_entry *pentry;
> +
> +	pentry = sfi_gpio_get_entry_by_name(name);
> +	if (!pentry)
> +		return ERR_PTR(-ENODEV);
> +
> +	return gpio_to_desc(pentry->pin_no);
> +}
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index bad400c..789ae1c 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -2451,6 +2451,9 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
>   	} else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
>   		dev_dbg(dev, "using ACPI for GPIO lookup\n");
>   		desc = acpi_find_gpio(dev, con_id, idx, &flags);
> +	} else if (IS_ENABLED(CONFIG_SFI)) {
> +		dev_dbg(dev, "using SFI for GPIO lookup\n");
> +		desc = sfi_get_gpiod_by_name(con_id);

Your lookup function is ignoring the dev argument. Are SFI GPIOs always 
supposed to be system-global? In this case, your if condition should 
likely be

	} else if (IS_ENABLED(CONFIG_SFI) && !dev) {

So that a global SFI GPIO does not get mistakenly assigned to a device 
that has, say, a more suited platform mapping on the same con_id.