From mboxrd@z Thu Jan  1 00:00:00 1970
From: timur@codeaurora.org (Timur Tabi)
Date: Fri, 14 Jul 2017 16:43:56 -0500
Subject: [PATCH 1/2] pinctrl: qcom: disable GPIO groups with no pins
In-Reply-To: <20170714171148.GH22780@codeaurora.org>
References: <1499982763-29619-1-git-send-email-timur@codeaurora.org>
 <1499982763-29619-2-git-send-email-timur@codeaurora.org>
 <20170714171148.GH22780@codeaurora.org>
Message-ID: <8eaeefc0-2f2c-a488-283f-80e26f4d13f5@codeaurora.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 07/14/2017 12:11 PM, Stephen Boyd wrote:
> gpiochips also have a request() hook. Can we use that before
> initializing direction to make sure the GPIO is accessible?

So I tried it, and it didn't work:

static int msm_gpio_request(struct gpio_chip *chip, unsigned int offset)
{
	pr_info("%s:%u offset=%u\n", __func__, __LINE__, offset);

	return 0;
}

static struct gpio_chip msm_gpio_template = {
	.request          = msm_gpio_request,
	...

msm_gpio_request() is never called when the driver loads.  In fact, I 
can't figure out when it would be called.

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