119 lines
2.5 KiB
C
119 lines
2.5 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/cd-gpio.h>
|
||
|
|
#include <linux/mmc/host.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
|
||
|
|
struct mmc_cd_gpio {
|
||
|
|
unsigned int gpio;
|
||
|
|
char label[0];
|
||
|
|
bool status;
|
||
|
|
};
|
||
|
|
|
||
|
|
static int mmc_cd_get_status(struct mmc_host *host)
|
||
|
|
{
|
||
|
|
int ret = -ENOSYS;
|
||
|
|
struct mmc_cd_gpio *cd = host->hotplug.handler_priv;
|
||
|
|
|
||
|
|
if (!cd || !gpio_is_valid(cd->gpio))
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
ret = !gpio_get_value_cansleep(cd->gpio) ^
|
||
|
|
!!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
|
||
|
|
out:
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static irqreturn_t mmc_cd_gpio_irqt(int irq, void *dev_id)
|
||
|
|
{
|
||
|
|
struct mmc_host *host = dev_id;
|
||
|
|
struct mmc_cd_gpio *cd = host->hotplug.handler_priv;
|
||
|
|
int status;
|
||
|
|
|
||
|
|
status = mmc_cd_get_status(host);
|
||
|
|
if (unlikely(status < 0))
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
if (status ^ cd->status) {
|
||
|
|
pr_info("%s: slot status change detected (%d -> %d), GPIO_ACTIVE_%s\n",
|
||
|
|
mmc_hostname(host), cd->status, status,
|
||
|
|
(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH) ?
|
||
|
|
"HIGH" : "LOW");
|
||
|
|
cd->status = status;
|
||
|
|
|
||
|
|
/* Schedule a card detection after a debounce timeout */
|
||
|
|
mmc_detect_change(host, msecs_to_jiffies(100));
|
||
|
|
}
|
||
|
|
out:
|
||
|
|
return IRQ_HANDLED;
|
||
|
|
}
|
||
|
|
|
||
|
|
int mmc_cd_gpio_request(struct mmc_host *host, unsigned int gpio)
|
||
|
|
{
|
||
|
|
size_t len = strlen(dev_name(host->parent)) + 4;
|
||
|
|
struct mmc_cd_gpio *cd;
|
||
|
|
int irq = gpio_to_irq(gpio);
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
if (irq < 0)
|
||
|
|
return irq;
|
||
|
|
|
||
|
|
cd = kmalloc(sizeof(*cd) + len, GFP_KERNEL);
|
||
|
|
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;
|
||
|
|
|
||
|
|
cd->gpio = gpio;
|
||
|
|
host->hotplug.irq = irq;
|
||
|
|
host->hotplug.handler_priv = cd;
|
||
|
|
|
||
|
|
ret = mmc_cd_get_status(host);
|
||
|
|
if (ret < 0)
|
||
|
|
goto eirqreq;
|
||
|
|
|
||
|
|
cd->status = ret;
|
||
|
|
|
||
|
|
ret = request_threaded_irq(irq, NULL, mmc_cd_gpio_irqt,
|
||
|
|
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
|
||
|
|
cd->label, host);
|
||
|
|
if (ret < 0)
|
||
|
|
goto eirqreq;
|
||
|
|
|
||
|
|
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);
|