From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1755877AbcCXOBr (ORCPT <rfc822;w@1wt.eu>);
	Thu, 24 Mar 2016 10:01:47 -0400
Received: from mga04.intel.com ([192.55.52.120]:41720 "EHLO mga04.intel.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1752871AbcCXOBi (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Thu, 24 Mar 2016 10:01:38 -0400
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.24,385,1455004800"; 
   d="scan'208";a="770643651"
Date: Thu, 24 Mar 2016 16:01:33 +0200
From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
        Alexandre Courbot <gnurou@gmail.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] gpio / ACPI: ignore GpioInt() GPIOs when requesting
 GPIO_OUT_*
Message-ID: <20160324140133.GT2099@lahna.fi.intel.com>
References: <20160323225831.GA28309@dtor-ws>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20160323225831.GA28309@dtor-ws>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, Mar 23, 2016 at 03:58:31PM -0700, Dmitry Torokhov wrote:
> From: Dmitry Torokhov <dtor@chromium.org>
> 
> When firmware does not use _DSD properties that allow properly name GPIO
> resources, the kernel falls back on parsing _CRS resources, and will
> return entries described as GpioInt() as general purpose GPIOs even
> though they are meant to be used simply as interrupt sources for the
> device:
> 
> Device (ETSA)
> {
> 	Name (_HID, "ELAN0001")
> 	...
> 
> 	Method(_CRS, 0x0, NotSerialized)
> 	{
> 		Name(BUF0,ResourceTemplate ()
> 		{
> 			I2CSerialBus(
> 				0x10,                     /* SlaveAddress */
> 				ControllerInitiated,      /* SlaveMode */
> 				400000,                   /* ConnectionSpeed */
> 				AddressingMode7Bit,       /* AddressingMode */
> 				"\\_SB.I2C1",             /* ResourceSource */
> 			)
> 			GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone,,
> 				 "\\_SB.GPSW") { BOARD_TOUCH_GPIO_INDEX }
> 		} )
> 		Return (BUF0)
> 	}
> ...
> }
> 
> This gives troubles with drivers such as Elan Touchscreen driver
> (elants_i2c) that uses devm_gpio_get to look up "reset" GPIO line and
> decide whether the driver is responsible for powering up and resetting
> the device or firmware is. In the above case the lookup succeeds, we map
> GPIO as output and later fail to request client->irq interrupt that is
> mapped to the same GPIO.
> 
> Let's ignore resources described as GpioInt() when requesting output
> GPIO (but allow them when requesting GPIOD_ASIS or GPIOD_IN as some
> drivers - i2c-hid - do request GPIO as input and then map it to
> interrupt with gpiod_to_irq).

You could mention here that we only ignore GpioInt() resources in
fallback case.

> BUG=chrome-os-partner:51154
> TEST=Boot Cyan, verify touchscreen work
> 
> Change-Id: Id20c730b937dce8a4135d2b64c8d798372d20e82

This is not needed for mainline patches :)

> Signed-off-by: Dmitry Torokhov <dtor@chromium.org>

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>