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.

-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc.  Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.