Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 | /*
* 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 {
int ro_gpio;
int cd_gpio;
char *ro_label;
char cd_label[0];
};
static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
{
/* Schedule a card detection after a debounce timeout */
struct mmc_host *host = dev_id;
if (host->ops->card_event)
host->ops->card_event(host);
mmc_detect_change(host, msecs_to_jiffies(200));
return IRQ_HANDLED;
}
static int mmc_gpio_alloc(struct mmc_host *host)
{
size_t len = strlen(dev_name(host->parent)) + 4;
struct mmc_gpio *ctx;
mutex_lock(&host->slot.lock);
ctx = host->slot.handler_priv;
if (!ctx) {
/*
* devm_kzalloc() can be called after device_initialize(), even
* before device_add(), i.e., between mmc_alloc_host() and
* mmc_add_host()
*/
ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + 2 * len,
GFP_KERNEL);
if (ctx) {
ctx->ro_label = ctx->cd_label + len;
snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent));
snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent));
ctx->cd_gpio = -EINVAL;
ctx->ro_gpio = -EINVAL;
host->slot.handler_priv = ctx;
}
}
mutex_unlock(&host->slot.lock);
return ctx ? 0 : -ENOMEM;
}
int mmc_gpio_get_ro(struct mmc_host *host)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
if (!ctx || !gpio_is_valid(ctx->ro_gpio))
return -ENOSYS;
return !gpio_get_value_cansleep(ctx->ro_gpio) ^
!!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
}
EXPORT_SYMBOL(mmc_gpio_get_ro);
int mmc_gpio_get_cd(struct mmc_host *host)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
if (!ctx || !gpio_is_valid(ctx->cd_gpio))
return -ENOSYS;
return !gpio_get_value_cansleep(ctx->cd_gpio) ^
!!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
}
EXPORT_SYMBOL(mmc_gpio_get_cd);
/**
* mmc_gpio_request_ro - request a gpio for write-protection
* @host: mmc host
* @gpio: gpio number requested
*
* As devm_* managed functions are used in mmc_gpio_request_ro(), client
* drivers do not need to explicitly call mmc_gpio_free_ro() for freeing up,
* if the requesting and freeing are only needed at probing and unbinding time
* for once. However, if client drivers do something special like runtime
* switching for write-protection, they are responsible for calling
* mmc_gpio_request_ro() and mmc_gpio_free_ro() as a pair on their own.
*
* Returns zero on success, else an error.
*/
int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
{
struct mmc_gpio *ctx;
int ret;
if (!gpio_is_valid(gpio))
return -EINVAL;
ret = mmc_gpio_alloc(host);
if (ret < 0)
return ret;
ctx = host->slot.handler_priv;
ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
ctx->ro_label);
if (ret < 0)
return ret;
ctx->ro_gpio = gpio;
return 0;
}
EXPORT_SYMBOL(mmc_gpio_request_ro);
/**
* mmc_gpio_request_cd - request a gpio for card-detection
* @host: mmc host
* @gpio: gpio number requested
*
* As devm_* managed functions are used in mmc_gpio_request_cd(), client
* drivers do not need to explicitly call mmc_gpio_free_cd() for freeing up,
* if the requesting and freeing are only needed at probing and unbinding time
* for once. However, if client drivers do something special like runtime
* switching for card-detection, they are responsible for calling
* mmc_gpio_request_cd() and mmc_gpio_free_cd() as a pair on their own.
*
* Returns zero on success, else an error.
*/
int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
{
struct mmc_gpio *ctx;
int irq = gpio_to_irq(gpio);
int ret;
ret = mmc_gpio_alloc(host);
if (ret < 0)
return ret;
ctx = host->slot.handler_priv;
ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
ctx->cd_label);
if (ret < 0)
/*
* don't bother freeing memory. It might still get used by other
* slot functions, in any case it will be freed, when the device
* is destroyed.
*/
return ret;
/*
* Even if gpio_to_irq() returns a valid IRQ number, the platform might
* still prefer to poll, e.g., because that IRQ number is already used
* by another unit and cannot be shared.
*/
if (irq >= 0 && host->caps & MMC_CAP_NEEDS_POLL)
irq = -EINVAL;
if (irq >= 0) {
ret = devm_request_threaded_irq(&host->class_dev, irq,
NULL, mmc_gpio_cd_irqt,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
ctx->cd_label, host);
if (ret < 0)
irq = ret;
}
host->slot.cd_irq = irq;
if (irq < 0)
host->caps |= MMC_CAP_NEEDS_POLL;
ctx->cd_gpio = gpio;
return 0;
}
EXPORT_SYMBOL(mmc_gpio_request_cd);
/**
* mmc_gpio_free_ro - free the write-protection gpio
* @host: mmc host
*
* It's provided only for cases that client drivers need to manually free
* up the write-protection gpio requested by mmc_gpio_request_ro().
*/
void mmc_gpio_free_ro(struct mmc_host *host)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
int gpio;
if (!ctx || !gpio_is_valid(ctx->ro_gpio))
return;
gpio = ctx->ro_gpio;
ctx->ro_gpio = -EINVAL;
devm_gpio_free(&host->class_dev, gpio);
}
EXPORT_SYMBOL(mmc_gpio_free_ro);
/**
* mmc_gpio_free_cd - free the card-detection gpio
* @host: mmc host
*
* It's provided only for cases that client drivers need to manually free
* up the card-detection gpio requested by mmc_gpio_request_cd().
*/
void mmc_gpio_free_cd(struct mmc_host *host)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
int gpio;
if (!ctx || !gpio_is_valid(ctx->cd_gpio))
return;
if (host->slot.cd_irq >= 0) {
devm_free_irq(&host->class_dev, host->slot.cd_irq, host);
host->slot.cd_irq = -EINVAL;
}
gpio = ctx->cd_gpio;
ctx->cd_gpio = -EINVAL;
devm_gpio_free(&host->class_dev, gpio);
}
EXPORT_SYMBOL(mmc_gpio_free_cd);
|