drivers/mmc/core/slot-gpio.c

   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/consumer.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>
  19
  20 #include "slot-gpio.h"
  21
  22 struct mmc_gpio {
  23         struct gpio_desc *ro_gpio;
  24         struct gpio_desc *cd_gpio;
  25         bool override_ro_active_level;
  26         bool override_cd_active_level;
  27         irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
  28         char *ro_label;
  29         char *cd_label;
  30         u32 cd_debounce_delay_ms;
  31 };
  32
  33 static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
  34 {
  35         /* Schedule a card detection after a debounce timeout */
  36         struct mmc_host *host = dev_id;
  37         struct mmc_gpio *ctx = host->slot.handler_priv;
  38
  39         host->trigger_card_event = true;
  40         mmc_detect_change(host, msecs_to_jiffies(ctx->cd_debounce_delay_ms));
  41
  42         return IRQ_HANDLED;
  43 }
  44
  45 int mmc_gpio_alloc(struct mmc_host *host)
  46 {
  47         struct mmc_gpio *ctx = devm_kzalloc(host->parent,
  48                                             sizeof(*ctx), GFP_KERNEL);
  49
  50         if (ctx) {
  51                 ctx->cd_debounce_delay_ms = 200;
  52                 ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL,
  53                                 "%s cd", dev_name(host->parent));
  54                 if (!ctx->cd_label)
  55                         return -ENOMEM;
  56                 ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL,
  57                                 "%s ro", dev_name(host->parent));
  58                 if (!ctx->ro_label)
  59                         return -ENOMEM;
  60                 host->slot.handler_priv = ctx;
  61                 host->slot.cd_irq = -EINVAL;
  62         }
  63
  64         return ctx ? 0 : -ENOMEM;
  65 }
  66
  67 int mmc_gpio_get_ro(struct mmc_host *host)
  68 {
  69         struct mmc_gpio *ctx = host->slot.handler_priv;
  70
  71         if (!ctx || !ctx->ro_gpio)
  72                 return -ENOSYS;
  73
  74         if (ctx->override_ro_active_level)
  75                 return !gpiod_get_raw_value_cansleep(ctx->ro_gpio) ^
  76                         !!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
  77
  78         return gpiod_get_value_cansleep(ctx->ro_gpio);
  79 }
  80 EXPORT_SYMBOL(mmc_gpio_get_ro);
  81
  82 int mmc_gpio_get_cd(struct mmc_host *host)
  83 {
  84         struct mmc_gpio *ctx = host->slot.handler_priv;
  85         int cansleep;
  86
  87         if (!ctx || !ctx->cd_gpio)
  88                 return -ENOSYS;
  89
  90         cansleep = gpiod_cansleep(ctx->cd_gpio);
  91         if (ctx->override_cd_active_level) {
  92                 int value = cansleep ?
  93                                 gpiod_get_raw_value_cansleep(ctx->cd_gpio) :
  94                                 gpiod_get_raw_value(ctx->cd_gpio);
  95                 return !value ^ !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
  96         }
  97
  98         return cansleep ?
  99                 gpiod_get_value_cansleep(ctx->cd_gpio) :
 100                 gpiod_get_value(ctx->cd_gpio);
 101 }
 102 EXPORT_SYMBOL(mmc_gpio_get_cd);
 103
 104 void mmc_gpiod_request_cd_irq(struct mmc_host *host)
 105 {
 106         struct mmc_gpio *ctx = host->slot.handler_priv;
 107         int irq = -EINVAL;
 108         int ret;
 109
 110         if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
 111                 return;
 112
 113         /*
 114          * Do not use IRQ if the platform prefers to poll, e.g., because that
 115          * IRQ number is already used by another unit and cannot be shared.
 116          */
 117         if (!(host->caps & MMC_CAP_NEEDS_POLL))
 118                 irq = gpiod_to_irq(ctx->cd_gpio);
 119
 120         if (irq >= 0) {
 121                 if (!ctx->cd_gpio_isr)
 122                         ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
 123                 ret = devm_request_threaded_irq(host->parent, irq,
 124                         NULL, ctx->cd_gpio_isr,
 125                         IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 126                         ctx->cd_label, host);
 127                 if (ret < 0)
 128                         irq = ret;
 129         }
 130
 131         host->slot.cd_irq = irq;
 132
 133         if (irq < 0)
 134                 host->caps |= MMC_CAP_NEEDS_POLL;
 135 }
 136 EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
 137
 138 int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
 139 {
 140         int ret = 0;
 141
 142         if (!(host->caps & MMC_CAP_CD_WAKE) ||
 143             host->slot.cd_irq < 0 ||
 144             on == host->slot.cd_wake_enabled)
 145                 return 0;
 146
 147         if (on) {
 148                 ret = enable_irq_wake(host->slot.cd_irq);
 149                 host->slot.cd_wake_enabled = !ret;
 150         } else {
 151                 disable_irq_wake(host->slot.cd_irq);
 152                 host->slot.cd_wake_enabled = false;
 153         }
 154
 155         return ret;
 156 }
 157 EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
 158
 159 /* Register an alternate interrupt service routine for
 160  * the card-detect GPIO.
 161  */
 162 void mmc_gpio_set_cd_isr(struct mmc_host *host,
 163                          irqreturn_t (*isr)(int irq, void *dev_id))
 164 {
 165         struct mmc_gpio *ctx = host->slot.handler_priv;
 166
 167         WARN_ON(ctx->cd_gpio_isr);
 168         ctx->cd_gpio_isr = isr;
 169 }
 170 EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
 171
 172 /**
 173  * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
 174  * @host: mmc host
 175  * @con_id: function within the GPIO consumer
 176  * @idx: index of the GPIO to obtain in the consumer
 177  * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
 178  * @debounce: debounce time in microseconds
 179  * @gpio_invert: will return whether the GPIO line is inverted or not, set
 180  * to NULL to ignore
 181  *
 182  * Note that this must be called prior to mmc_add_host()
 183  * otherwise the caller must also call mmc_gpiod_request_cd_irq().
 184  *
 185  * Returns zero on success, else an error.
 186  */
 187 int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
 188                          unsigned int idx, bool override_active_level,
 189                          unsigned int debounce, bool *gpio_invert)
 190 {
 191         struct mmc_gpio *ctx = host->slot.handler_priv;
 192         struct gpio_desc *desc;
 193         int ret;
 194
 195         desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
 196         if (IS_ERR(desc))
 197                 return PTR_ERR(desc);
 198
 199         if (debounce) {
 200                 ret = gpiod_set_debounce(desc, debounce);
 201                 if (ret < 0)
 202                         ctx->cd_debounce_delay_ms = debounce / 1000;
 203         }
 204
 205         if (gpio_invert)
 206                 *gpio_invert = !gpiod_is_active_low(desc);
 207
 208         ctx->override_cd_active_level = override_active_level;
 209         ctx->cd_gpio = desc;
 210
 211         return 0;
 212 }
 213 EXPORT_SYMBOL(mmc_gpiod_request_cd);
 214
 215 bool mmc_can_gpio_cd(struct mmc_host *host)
 216 {
 217         struct mmc_gpio *ctx = host->slot.handler_priv;
 218
 219         return ctx->cd_gpio ? true : false;
 220 }
 221 EXPORT_SYMBOL(mmc_can_gpio_cd);
 222
 223 /**
 224  * mmc_gpiod_request_ro - request a gpio descriptor for write protection
 225  * @host: mmc host
 226  * @con_id: function within the GPIO consumer
 227  * @idx: index of the GPIO to obtain in the consumer
 228  * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
 229  * @debounce: debounce time in microseconds
 230  * @gpio_invert: will return whether the GPIO line is inverted or not,
 231  * set to NULL to ignore
 232  *
 233  * Returns zero on success, else an error.
 234  */
 235 int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
 236                          unsigned int idx, bool override_active_level,
 237                          unsigned int debounce, bool *gpio_invert)
 238 {
 239         struct mmc_gpio *ctx = host->slot.handler_priv;
 240         struct gpio_desc *desc;
 241         int ret;
 242
 243         desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
 244         if (IS_ERR(desc))
 245                 return PTR_ERR(desc);
 246
 247         if (debounce) {
 248                 ret = gpiod_set_debounce(desc, debounce);
 249                 if (ret < 0)
 250                         return ret;
 251         }
 252
 253         if (gpio_invert)
 254                 *gpio_invert = !gpiod_is_active_low(desc);
 255
 256         ctx->override_ro_active_level = override_active_level;
 257         ctx->ro_gpio = desc;
 258
 259         return 0;
 260 }
 261 EXPORT_SYMBOL(mmc_gpiod_request_ro);
 262
 263 bool mmc_can_gpio_ro(struct mmc_host *host)
 264 {
 265         struct mmc_gpio *ctx = host->slot.handler_priv;
 266
 267         return ctx->ro_gpio ? true : false;
 268 }
 269 EXPORT_SYMBOL(mmc_can_gpio_ro);