Commit | Line | Data |
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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> | |
5ca65188 | 15 | #include <linux/mmc/cd-gpio.h> |
349ab524 GL |
16 | #include <linux/mmc/host.h> |
17 | #include <linux/module.h> | |
18 | #include <linux/slab.h> | |
19 | ||
20 | struct mmc_cd_gpio { | |
21 | unsigned int gpio; | |
22 | char label[0]; | |
23 | }; | |
24 | ||
25 | static irqreturn_t mmc_cd_gpio_irqt(int irq, void *dev_id) | |
26 | { | |
27 | /* Schedule a card detection after a debounce timeout */ | |
28 | mmc_detect_change(dev_id, msecs_to_jiffies(100)); | |
29 | return IRQ_HANDLED; | |
30 | } | |
31 | ||
c9b0546a | 32 | int mmc_cd_gpio_request(struct mmc_host *host, unsigned int gpio) |
349ab524 GL |
33 | { |
34 | size_t len = strlen(dev_name(host->parent)) + 4; | |
c9b0546a GL |
35 | struct mmc_cd_gpio *cd; |
36 | int irq = gpio_to_irq(gpio); | |
349ab524 GL |
37 | int ret; |
38 | ||
c9b0546a GL |
39 | if (irq < 0) |
40 | return irq; | |
41 | ||
42 | cd = kmalloc(sizeof(*cd) + len, GFP_KERNEL); | |
349ab524 GL |
43 | if (!cd) |
44 | return -ENOMEM; | |
45 | ||
46 | snprintf(cd->label, len, "%s cd", dev_name(host->parent)); | |
47 | ||
48 | ret = gpio_request_one(gpio, GPIOF_DIR_IN, cd->label); | |
49 | if (ret < 0) | |
50 | goto egpioreq; | |
51 | ||
52 | ret = request_threaded_irq(irq, NULL, mmc_cd_gpio_irqt, | |
623b51fc GL |
53 | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | |
54 | IRQF_ONESHOT, cd->label, host); | |
349ab524 GL |
55 | if (ret < 0) |
56 | goto eirqreq; | |
57 | ||
58 | cd->gpio = gpio; | |
59 | host->hotplug.irq = irq; | |
60 | host->hotplug.handler_priv = cd; | |
61 | ||
62 | return 0; | |
63 | ||
64 | eirqreq: | |
65 | gpio_free(gpio); | |
66 | egpioreq: | |
67 | kfree(cd); | |
68 | return ret; | |
69 | } | |
70 | EXPORT_SYMBOL(mmc_cd_gpio_request); | |
71 | ||
72 | void mmc_cd_gpio_free(struct mmc_host *host) | |
73 | { | |
74 | struct mmc_cd_gpio *cd = host->hotplug.handler_priv; | |
75 | ||
0e9f480b GL |
76 | if (!cd) |
77 | return; | |
78 | ||
349ab524 GL |
79 | free_irq(host->hotplug.irq, host); |
80 | gpio_free(cd->gpio); | |
81 | kfree(cd); | |
82 | } | |
83 | EXPORT_SYMBOL(mmc_cd_gpio_free); |