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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 | /*
* 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/gpio/consumer.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>
#include "slot-gpio.h"
struct mmc_gpio {
struct gpio_desc *ro_gpio;
struct gpio_desc *cd_gpio;
bool override_ro_active_level;
bool override_cd_active_level;
irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
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;
host->trigger_card_event = true;
mmc_detect_change(host, msecs_to_jiffies(200));
return IRQ_HANDLED;
}
int mmc_gpio_alloc(struct mmc_host *host)
{
size_t len = strlen(dev_name(host->parent)) + 4;
struct mmc_gpio *ctx = devm_kzalloc(host->parent,
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));
host->slot.handler_priv = ctx;
host->slot.cd_irq = -EINVAL;
}
return ctx ? 0 : -ENOMEM;
}
int mmc_gpio_get_ro(struct mmc_host *host)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
if (!ctx || !ctx->ro_gpio)
return -ENOSYS;
if (ctx->override_ro_active_level)
return !gpiod_get_raw_value_cansleep(ctx->ro_gpio) ^
!!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
return gpiod_get_value_cansleep(ctx->ro_gpio);
}
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 || !ctx->cd_gpio)
return -ENOSYS;
if (ctx->override_cd_active_level)
return !gpiod_get_raw_value_cansleep(ctx->cd_gpio) ^
!!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
return gpiod_get_value_cansleep(ctx->cd_gpio);
}
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 worry about freeing up memory.
*
* Returns zero on success, else an error.
*/
int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
int ret;
if (!gpio_is_valid(gpio))
return -EINVAL;
ret = devm_gpio_request_one(host->parent, gpio, GPIOF_DIR_IN,
ctx->ro_label);
if (ret < 0)
return ret;
ctx->override_ro_active_level = true;
ctx->ro_gpio = gpio_to_desc(gpio);
return 0;
}
EXPORT_SYMBOL(mmc_gpio_request_ro);
void mmc_gpiod_request_cd_irq(struct mmc_host *host)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
int ret, irq;
if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
return;
irq = gpiod_to_irq(ctx->cd_gpio);
/*
* Even if gpiod_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) {
if (!ctx->cd_gpio_isr)
ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
ret = devm_request_threaded_irq(host->parent, irq,
NULL, ctx->cd_gpio_isr,
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;
}
EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
/* Register an alternate interrupt service routine for
* the card-detect GPIO.
*/
void mmc_gpio_set_cd_isr(struct mmc_host *host,
irqreturn_t (*isr)(int irq, void *dev_id))
{
struct mmc_gpio *ctx = host->slot.handler_priv;
WARN_ON(ctx->cd_gpio_isr);
ctx->cd_gpio_isr = isr;
}
EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
/**
* mmc_gpio_request_cd - request a gpio for card-detection
* @host: mmc host
* @gpio: gpio number requested
* @debounce: debounce time in microseconds
*
* As devm_* managed functions are used in mmc_gpio_request_cd(), client
* drivers do not need to worry about freeing up memory.
*
* If GPIO debouncing is desired, set the debounce parameter to a non-zero
* value. The caller is responsible for ensuring that the GPIO driver associated
* with the GPIO supports debouncing, otherwise an error will be returned.
*
* Returns zero on success, else an error.
*/
int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
unsigned int debounce)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
int ret;
ret = devm_gpio_request_one(host->parent, 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;
if (debounce) {
ret = gpio_set_debounce(gpio, debounce);
if (ret < 0)
return ret;
}
ctx->override_cd_active_level = true;
ctx->cd_gpio = gpio_to_desc(gpio);
return 0;
}
EXPORT_SYMBOL(mmc_gpio_request_cd);
/**
* mmc_gpiod_request_cd - request a gpio descriptor for card-detection
* @host: mmc host
* @con_id: function within the GPIO consumer
* @idx: index of the GPIO to obtain in the consumer
* @override_active_level: ignore %GPIO_ACTIVE_LOW flag
* @debounce: debounce time in microseconds
* @gpio_invert: will return whether the GPIO line is inverted or not, set
* to NULL to ignore
*
* Use this function in place of mmc_gpio_request_cd() to use the GPIO
* descriptor API. Note that it must be called prior to mmc_add_host()
* otherwise the caller must also call mmc_gpiod_request_cd_irq().
*
* Returns zero on success, else an error.
*/
int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
unsigned int idx, bool override_active_level,
unsigned int debounce, bool *gpio_invert)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
struct gpio_desc *desc;
int ret;
if (!con_id)
con_id = ctx->cd_label;
desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
if (IS_ERR(desc))
return PTR_ERR(desc);
if (debounce) {
ret = gpiod_set_debounce(desc, debounce);
if (ret < 0)
return ret;
}
if (gpio_invert)
*gpio_invert = !gpiod_is_active_low(desc);
ctx->override_cd_active_level = override_active_level;
ctx->cd_gpio = desc;
return 0;
}
EXPORT_SYMBOL(mmc_gpiod_request_cd);
/**
* mmc_gpiod_request_ro - request a gpio descriptor for write protection
* @host: mmc host
* @con_id: function within the GPIO consumer
* @idx: index of the GPIO to obtain in the consumer
* @override_active_level: ignore %GPIO_ACTIVE_LOW flag
* @debounce: debounce time in microseconds
* @gpio_invert: will return whether the GPIO line is inverted or not,
* set to NULL to ignore
*
* Use this function in place of mmc_gpio_request_ro() to use the GPIO
* descriptor API.
*
* Returns zero on success, else an error.
*/
int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
unsigned int idx, bool override_active_level,
unsigned int debounce, bool *gpio_invert)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
struct gpio_desc *desc;
int ret;
if (!con_id)
con_id = ctx->ro_label;
desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
if (IS_ERR(desc))
return PTR_ERR(desc);
if (debounce) {
ret = gpiod_set_debounce(desc, debounce);
if (ret < 0)
return ret;
}
if (gpio_invert)
*gpio_invert = !gpiod_is_active_low(desc);
ctx->override_ro_active_level = override_active_level;
ctx->ro_gpio = desc;
return 0;
}
EXPORT_SYMBOL(mmc_gpiod_request_ro);
|