projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 349ab524 GL |
1 | /* |
| 2 | * Generic GPIO card-detect helper | |
| 3 | * | |
| 4 | * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de> | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License version 2 as | |
| 8 | * published by the Free Software Foundation. | |
| 9 | */ | |
| 10 | ||
| 11 | #include <linux/err.h> | |
| 12 | #include <linux/gpio.h> | |
| 13 | #include <linux/interrupt.h> | |
| 14 | #include <linux/jiffies.h> | |
| 15 | #include <linux/mmc/host.h> | |
| 16 | #include <linux/module.h> | |
| 17 | #include <linux/slab.h> | |
| 18 | ||
| 19 | struct mmc_cd_gpio { | |
| 20 | unsigned int gpio; | |
| 21 | char label[0]; | |
| 22 | }; | |
| 23 | ||
| 24 | static irqreturn_t mmc_cd_gpio_irqt(int irq, void *dev_id) | |
| 25 | { | |
| 26 | /* Schedule a card detection after a debounce timeout */ | |
| 27 | mmc_detect_change(dev_id, msecs_to_jiffies(100)); | |
| 28 | return IRQ_HANDLED; | |
| 29 | } | |
| 30 | ||
| 31 | int mmc_cd_gpio_request(struct mmc_host *host, unsigned int gpio, | |
| 32 | unsigned int irq, unsigned long flags) | |
| 33 | { | |
| 34 | size_t len = strlen(dev_name(host->parent)) + 4; | |
| 35 | struct mmc_cd_gpio *cd = kmalloc(sizeof(*cd) + len, GFP_KERNEL); | |
| 36 | int ret; | |
| 37 | ||
| 38 | if (!cd) | |
| 39 | return -ENOMEM; | |
| 40 | ||
| 41 | snprintf(cd->label, len, "%s cd", dev_name(host->parent)); | |
| 42 | ||
| 43 | ret = gpio_request_one(gpio, GPIOF_DIR_IN, cd->label); | |
| 44 | if (ret < 0) | |
| 45 | goto egpioreq; | |
| 46 | ||
| 47 | ret = request_threaded_irq(irq, NULL, mmc_cd_gpio_irqt, | |
| 48 | flags, cd->label, host); | |
| 49 | if (ret < 0) | |
| 50 | goto eirqreq; | |
| 51 | ||
| 52 | cd->gpio = gpio; | |
| 53 | host->hotplug.irq = irq; | |
| 54 | host->hotplug.handler_priv = cd; | |
| 55 | ||
| 56 | return 0; | |
| 57 | ||
| 58 | eirqreq: | |
| 59 | gpio_free(gpio); | |
| 60 | egpioreq: | |
| 61 | kfree(cd); | |
| 62 | return ret; | |
| 63 | } | |
| 64 | EXPORT_SYMBOL(mmc_cd_gpio_request); | |
| 65 | ||
| 66 | void mmc_cd_gpio_free(struct mmc_host *host) | |
| 67 | { | |
| 68 | struct mmc_cd_gpio *cd = host->hotplug.handler_priv; | |
| 69 | ||
| 70 | free_irq(host->hotplug.irq, host); | |
| 71 | gpio_free(cd->gpio); | |
| 72 | kfree(cd); | |
| 73 | } | |
| 74 | EXPORT_SYMBOL(mmc_cd_gpio_free); |