drivers/mmc/core/slot-gpio.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Generic GPIO card-detect helper
   4  *
   5  * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
   6  */
   7
   8 #include <linux/err.h>
   9 #include <linux/gpio/consumer.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/jiffies.h>
  12 #include <linux/mmc/host.h>
  13 #include <linux/mmc/slot-gpio.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16
  17 #include "slot-gpio.h"
  18
  19 struct mmc_gpio {
  20         struct gpio_desc *ro_gpio;
  21         struct gpio_desc *cd_gpio;
  22         bool override_cd_active_level;
  23         irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
  24         char *ro_label;
  25         char *cd_label;
  26         u32 cd_debounce_delay_ms;
  27 };
  28
  29 static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
  30 {
  31         /* Schedule a card detection after a debounce timeout */
  32         struct mmc_host *host = dev_id;
  33         struct mmc_gpio *ctx = host->slot.handler_priv;
  34
  35         host->trigger_card_event = true;
  36         mmc_detect_change(host, msecs_to_jiffies(ctx->cd_debounce_delay_ms));
  37
  38         return IRQ_HANDLED;
  39 }
  40
  41 int mmc_gpio_alloc(struct mmc_host *host)
  42 {
  43         struct mmc_gpio *ctx = devm_kzalloc(host->parent,
  44                                             sizeof(*ctx), GFP_KERNEL);
  45
  46         if (ctx) {
  47                 ctx->cd_debounce_delay_ms = 200;
  48                 ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL,
  49                                 "%s cd", dev_name(host->parent));
  50                 if (!ctx->cd_label)
  51                         return -ENOMEM;
  52                 ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL,
  53                                 "%s ro", dev_name(host->parent));
  54                 if (!ctx->ro_label)
  55                         return -ENOMEM;
  56                 host->slot.handler_priv = ctx;
  57                 host->slot.cd_irq = -EINVAL;
  58         }
  59
  60         return ctx ? 0 : -ENOMEM;
  61 }
  62
  63 int mmc_gpio_get_ro(struct mmc_host *host)
  64 {
  65         struct mmc_gpio *ctx = host->slot.handler_priv;
  66
  67         if (!ctx || !ctx->ro_gpio)
  68                 return -ENOSYS;
  69
  70         return gpiod_get_value_cansleep(ctx->ro_gpio);
  71 }
  72 EXPORT_SYMBOL(mmc_gpio_get_ro);
  73
  74 int mmc_gpio_get_cd(struct mmc_host *host)
  75 {
  76         struct mmc_gpio *ctx = host->slot.handler_priv;
  77         int cansleep;
  78
  79         if (!ctx || !ctx->cd_gpio)
  80                 return -ENOSYS;
  81
  82         cansleep = gpiod_cansleep(ctx->cd_gpio);
  83         if (ctx->override_cd_active_level) {
  84                 int value = cansleep ?
  85                                 gpiod_get_raw_value_cansleep(ctx->cd_gpio) :
  86                                 gpiod_get_raw_value(ctx->cd_gpio);
  87                 return !value ^ !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
  88         }
  89
  90         return cansleep ?
  91                 gpiod_get_value_cansleep(ctx->cd_gpio) :
  92                 gpiod_get_value(ctx->cd_gpio);
  93 }
  94 EXPORT_SYMBOL(mmc_gpio_get_cd);
  95
  96 void mmc_gpiod_request_cd_irq(struct mmc_host *host)
  97 {
  98         struct mmc_gpio *ctx = host->slot.handler_priv;
  99         int irq = -EINVAL;
 100         int ret;
 101
 102         if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
 103                 return;
 104
 105         /*
 106          * Do not use IRQ if the platform prefers to poll, e.g., because that
 107          * IRQ number is already used by another unit and cannot be shared.
 108          */
 109         if (!(host->caps & MMC_CAP_NEEDS_POLL))
 110                 irq = gpiod_to_irq(ctx->cd_gpio);
 111
 112         if (irq >= 0) {
 113                 if (!ctx->cd_gpio_isr)
 114                         ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
 115                 ret = devm_request_threaded_irq(host->parent, irq,
 116                         NULL, ctx->cd_gpio_isr,
 117                         IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 118                         ctx->cd_label, host);
 119                 if (ret < 0)
 120                         irq = ret;
 121         }
 122
 123         host->slot.cd_irq = irq;
 124
 125         if (irq < 0)
 126                 host->caps |= MMC_CAP_NEEDS_POLL;
 127 }
 128 EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
 129
 130 int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
 131 {
 132         int ret = 0;
 133
 134         if (!(host->caps & MMC_CAP_CD_WAKE) ||
 135             host->slot.cd_irq < 0 ||
 136             on == host->slot.cd_wake_enabled)
 137                 return 0;
 138
 139         if (on) {
 140                 ret = enable_irq_wake(host->slot.cd_irq);
 141                 host->slot.cd_wake_enabled = !ret;
 142         } else {
 143                 disable_irq_wake(host->slot.cd_irq);
 144                 host->slot.cd_wake_enabled = false;
 145         }
 146
 147         return ret;
 148 }
 149 EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
 150
 151 /* Register an alternate interrupt service routine for
 152  * the card-detect GPIO.
 153  */
 154 void mmc_gpio_set_cd_isr(struct mmc_host *host,
 155                          irqreturn_t (*isr)(int irq, void *dev_id))
 156 {
 157         struct mmc_gpio *ctx = host->slot.handler_priv;
 158
 159         WARN_ON(ctx->cd_gpio_isr);
 160         ctx->cd_gpio_isr = isr;
 161 }
 162 EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
 163
 164 /**
 165  * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
 166  * @host: mmc host
 167  * @con_id: function within the GPIO consumer
 168  * @idx: index of the GPIO to obtain in the consumer
 169  * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
 170  * @debounce: debounce time in microseconds
 171  * @gpio_invert: will return whether the GPIO line is inverted or not, set
 172  * to NULL to ignore
 173  *
 174  * Note that this must be called prior to mmc_add_host()
 175  * otherwise the caller must also call mmc_gpiod_request_cd_irq().
 176  *
 177  * Returns zero on success, else an error.
 178  */
 179 int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
 180                          unsigned int idx, bool override_active_level,
 181                          unsigned int debounce, bool *gpio_invert)
 182 {
 183         struct mmc_gpio *ctx = host->slot.handler_priv;
 184         struct gpio_desc *desc;
 185         int ret;
 186
 187         desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
 188         if (IS_ERR(desc))
 189                 return PTR_ERR(desc);
 190
 191         if (debounce) {
 192                 ret = gpiod_set_debounce(desc, debounce);
 193                 if (ret < 0)
 194                         ctx->cd_debounce_delay_ms = debounce / 1000;
 195         }
 196
 197         if (gpio_invert)
 198                 *gpio_invert = !gpiod_is_active_low(desc);
 199
 200         ctx->override_cd_active_level = override_active_level;
 201         ctx->cd_gpio = desc;
 202
 203         return 0;
 204 }
 205 EXPORT_SYMBOL(mmc_gpiod_request_cd);
 206
 207 bool mmc_can_gpio_cd(struct mmc_host *host)
 208 {
 209         struct mmc_gpio *ctx = host->slot.handler_priv;
 210
 211         return ctx->cd_gpio ? true : false;
 212 }
 213 EXPORT_SYMBOL(mmc_can_gpio_cd);
 214
 215 /**
 216  * mmc_gpiod_request_ro - request a gpio descriptor for write protection
 217  * @host: mmc host
 218  * @con_id: function within the GPIO consumer
 219  * @idx: index of the GPIO to obtain in the consumer
 220  * @debounce: debounce time in microseconds
 221  * @gpio_invert: will return whether the GPIO line is inverted or not,
 222  * set to NULL to ignore
 223  *
 224  * Returns zero on success, else an error.
 225  */
 226 int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
 227                          unsigned int idx,
 228                          unsigned int debounce, bool *gpio_invert)
 229 {
 230         struct mmc_gpio *ctx = host->slot.handler_priv;
 231         struct gpio_desc *desc;
 232         int ret;
 233
 234         desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
 235         if (IS_ERR(desc))
 236                 return PTR_ERR(desc);
 237
 238         if (debounce) {
 239                 ret = gpiod_set_debounce(desc, debounce);
 240                 if (ret < 0)
 241                         return ret;
 242         }
 243
 244         if (gpio_invert)
 245                 *gpio_invert = !gpiod_is_active_low(desc);
 246
 247         ctx->ro_gpio = desc;
 248
 249         return 0;
 250 }
 251 EXPORT_SYMBOL(mmc_gpiod_request_ro);
 252
 253 bool mmc_can_gpio_ro(struct mmc_host *host)
 254 {
 255         struct mmc_gpio *ctx = host->slot.handler_priv;
 256
 257         return ctx->ro_gpio ? true : false;
 258 }
 259 EXPORT_SYMBOL(mmc_can_gpio_ro);