| /* |
| * 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; |
| bool status; |
| char label[0]; |
| }; |
| |
| 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; |
| |
| if (!cd || !gpio_is_valid(cd->gpio)) |
| return; |
| |
| free_irq(host->hotplug.irq, host); |
| gpio_free(cd->gpio); |
| cd->gpio = -EINVAL; |
| kfree(cd); |
| } |
| EXPORT_SYMBOL(mmc_cd_gpio_free); |