mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-28 04:17:47 +00:00
349ab52446
This patch adds a primitive helper to support card hotplug detection on platforms, where a GPIO, capable of producing interrupts, is used for detection of card-insertion and -removal events. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Chris Ball <cjb@laptop.org>
75 lines
1.6 KiB
C
75 lines
1.6 KiB
C
/*
|
|
* Generic GPIO card-detect helper
|
|
*
|
|
* Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
|
|
*
|
|
* 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/err.h>
|
|
#include <linux/gpio.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/mmc/host.h>
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
|
|
struct mmc_cd_gpio {
|
|
unsigned int gpio;
|
|
char label[0];
|
|
};
|
|
|
|
static irqreturn_t mmc_cd_gpio_irqt(int irq, void *dev_id)
|
|
{
|
|
/* Schedule a card detection after a debounce timeout */
|
|
mmc_detect_change(dev_id, msecs_to_jiffies(100));
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
int mmc_cd_gpio_request(struct mmc_host *host, unsigned int gpio,
|
|
unsigned int irq, unsigned long flags)
|
|
{
|
|
size_t len = strlen(dev_name(host->parent)) + 4;
|
|
struct mmc_cd_gpio *cd = kmalloc(sizeof(*cd) + len, GFP_KERNEL);
|
|
int ret;
|
|
|
|
if (!cd)
|
|
return -ENOMEM;
|
|
|
|
snprintf(cd->label, len, "%s cd", dev_name(host->parent));
|
|
|
|
ret = gpio_request_one(gpio, GPIOF_DIR_IN, cd->label);
|
|
if (ret < 0)
|
|
goto egpioreq;
|
|
|
|
ret = request_threaded_irq(irq, NULL, mmc_cd_gpio_irqt,
|
|
flags, cd->label, host);
|
|
if (ret < 0)
|
|
goto eirqreq;
|
|
|
|
cd->gpio = gpio;
|
|
host->hotplug.irq = irq;
|
|
host->hotplug.handler_priv = cd;
|
|
|
|
return 0;
|
|
|
|
eirqreq:
|
|
gpio_free(gpio);
|
|
egpioreq:
|
|
kfree(cd);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(mmc_cd_gpio_request);
|
|
|
|
void mmc_cd_gpio_free(struct mmc_host *host)
|
|
{
|
|
struct mmc_cd_gpio *cd = host->hotplug.handler_priv;
|
|
|
|
free_irq(host->hotplug.irq, host);
|
|
gpio_free(cd->gpio);
|
|
kfree(cd);
|
|
}
|
|
EXPORT_SYMBOL(mmc_cd_gpio_free);
|