2 * Generic GPIO card-detect helper
4 * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
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.
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/mmc/slot-gpio.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
27 static irqreturn_t
mmc_gpio_cd_irqt(int irq
, void *dev_id
)
29 /* Schedule a card detection after a debounce timeout */
30 mmc_detect_change(dev_id
, msecs_to_jiffies(100));
34 static int mmc_gpio_alloc(struct mmc_host
*host
)
36 size_t len
= strlen(dev_name(host
->parent
)) + 4;
39 mutex_lock(&host
->slot
.lock
);
41 ctx
= host
->slot
.handler_priv
;
44 * devm_kzalloc() can be called after device_initialize(), even
45 * before device_add(), i.e., between mmc_alloc_host() and
48 ctx
= devm_kzalloc(&host
->class_dev
, sizeof(*ctx
) + 2 * len
,
51 ctx
->ro_label
= ctx
->cd_label
+ len
;
52 snprintf(ctx
->cd_label
, len
, "%s cd", dev_name(host
->parent
));
53 snprintf(ctx
->ro_label
, len
, "%s ro", dev_name(host
->parent
));
54 ctx
->cd_gpio
= -EINVAL
;
55 ctx
->ro_gpio
= -EINVAL
;
56 host
->slot
.handler_priv
= ctx
;
60 mutex_unlock(&host
->slot
.lock
);
62 return ctx
? 0 : -ENOMEM
;
65 int mmc_gpio_get_ro(struct mmc_host
*host
)
67 struct mmc_gpio
*ctx
= host
->slot
.handler_priv
;
69 if (!ctx
|| !gpio_is_valid(ctx
->ro_gpio
))
72 return !gpio_get_value_cansleep(ctx
->ro_gpio
) ^
73 !!(host
->caps2
& MMC_CAP2_RO_ACTIVE_HIGH
);
75 EXPORT_SYMBOL(mmc_gpio_get_ro
);
77 int mmc_gpio_get_cd(struct mmc_host
*host
)
79 struct mmc_gpio
*ctx
= host
->slot
.handler_priv
;
81 if (!ctx
|| !gpio_is_valid(ctx
->cd_gpio
))
84 return !gpio_get_value_cansleep(ctx
->cd_gpio
) ^
85 !!(host
->caps2
& MMC_CAP2_CD_ACTIVE_HIGH
);
87 EXPORT_SYMBOL(mmc_gpio_get_cd
);
89 int mmc_gpio_request_ro(struct mmc_host
*host
, unsigned int gpio
)
94 if (!gpio_is_valid(gpio
))
97 ret
= mmc_gpio_alloc(host
);
101 ctx
= host
->slot
.handler_priv
;
103 return gpio_request_one(gpio
, GPIOF_DIR_IN
, ctx
->ro_label
);
105 EXPORT_SYMBOL(mmc_gpio_request_ro
);
107 int mmc_gpio_request_cd(struct mmc_host
*host
, unsigned int gpio
)
109 struct mmc_gpio
*ctx
;
110 int irq
= gpio_to_irq(gpio
);
113 ret
= mmc_gpio_alloc(host
);
117 ctx
= host
->slot
.handler_priv
;
119 ret
= gpio_request_one(gpio
, GPIOF_DIR_IN
, ctx
->cd_label
);
122 * don't bother freeing memory. It might still get used by other
123 * slot functions, in any case it will be freed, when the device
129 * Even if gpio_to_irq() returns a valid IRQ number, the platform might
130 * still prefer to poll, e.g., because that IRQ number is already used
131 * by another unit and cannot be shared.
133 if (irq
>= 0 && host
->caps
& MMC_CAP_NEEDS_POLL
)
137 ret
= request_threaded_irq(irq
, NULL
, mmc_gpio_cd_irqt
,
138 IRQF_TRIGGER_RISING
| IRQF_TRIGGER_FALLING
| IRQF_ONESHOT
,
139 ctx
->cd_label
, host
);
144 host
->slot
.cd_irq
= irq
;
147 host
->caps
|= MMC_CAP_NEEDS_POLL
;
153 EXPORT_SYMBOL(mmc_gpio_request_cd
);
155 void mmc_gpio_free_ro(struct mmc_host
*host
)
157 struct mmc_gpio
*ctx
= host
->slot
.handler_priv
;
160 if (!ctx
|| !gpio_is_valid(ctx
->ro_gpio
))
164 ctx
->ro_gpio
= -EINVAL
;
168 EXPORT_SYMBOL(mmc_gpio_free_ro
);
170 void mmc_gpio_free_cd(struct mmc_host
*host
)
172 struct mmc_gpio
*ctx
= host
->slot
.handler_priv
;
175 if (!ctx
|| !gpio_is_valid(ctx
->cd_gpio
))
178 if (host
->slot
.cd_irq
>= 0) {
179 free_irq(host
->slot
.cd_irq
, host
);
180 host
->slot
.cd_irq
= -EINVAL
;
184 ctx
->cd_gpio
= -EINVAL
;
188 EXPORT_SYMBOL(mmc_gpio_free_cd
);