| /* |
| * 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/mmc/slot-gpio.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| |
| struct mmc_gpio { |
| unsigned int cd_gpio; |
| char cd_label[0]; |
| }; |
| |
| static irqreturn_t mmc_gpio_cd_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_gpio_request_cd(struct mmc_host *host, unsigned int gpio) |
| { |
| size_t len = strlen(dev_name(host->parent)) + 4; |
| struct mmc_gpio *ctx; |
| int irq = gpio_to_irq(gpio); |
| int ret; |
| |
| if (irq < 0) |
| return irq; |
| |
| ctx = kmalloc(sizeof(*ctx) + len, GFP_KERNEL); |
| if (!ctx) |
| return -ENOMEM; |
| |
| snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent)); |
| |
| ret = gpio_request_one(gpio, GPIOF_DIR_IN, ctx->cd_label); |
| if (ret < 0) |
| goto egpioreq; |
| |
| ret = request_threaded_irq(irq, NULL, mmc_gpio_cd_irqt, |
| IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
| ctx->cd_label, host); |
| if (ret < 0) |
| goto eirqreq; |
| |
| ctx->cd_gpio = gpio; |
| host->hotplug.irq = irq; |
| host->hotplug.handler_priv = ctx; |
| |
| return 0; |
| |
| eirqreq: |
| gpio_free(gpio); |
| egpioreq: |
| kfree(ctx); |
| return ret; |
| } |
| EXPORT_SYMBOL(mmc_gpio_request_cd); |
| |
| void mmc_gpio_free_cd(struct mmc_host *host) |
| { |
| struct mmc_gpio *ctx = host->hotplug.handler_priv; |
| |
| if (!ctx) |
| return; |
| |
| free_irq(host->hotplug.irq, host); |
| gpio_free(ctx->cd_gpio); |
| kfree(ctx); |
| } |
| EXPORT_SYMBOL(mmc_gpio_free_cd); |