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         irq_handler_t cd_gpio_isr;
  23         char *ro_label;
  24         char *cd_label;
  25         u32 cd_debounce_delay_ms;
  26         int cd_irq;
  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         const char *devname = dev_name(host->parent);
  44         struct mmc_gpio *ctx;
  45
  46         ctx = devm_kzalloc(host->parent, sizeof(*ctx), GFP_KERNEL);
  47         if (!ctx)
  48                 return -ENOMEM;
  49
  50         ctx->cd_debounce_delay_ms = 200;
  51         ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL, "%s cd", devname);
  52         if (!ctx->cd_label)
  53                 return -ENOMEM;
  54         ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL, "%s ro", devname);
  55         if (!ctx->ro_label)
  56                 return -ENOMEM;
  57         ctx->cd_irq = -EINVAL;
  58         host->slot.handler_priv = ctx;
  59         host->slot.cd_irq = -EINVAL;
  60
  61         return 0;
  62 }
  63
  64 void mmc_gpio_set_cd_irq(struct mmc_host *host, int irq)
  65 {
  66         struct mmc_gpio *ctx = host->slot.handler_priv;
  67
  68         if (!ctx || irq < 0)
  69                 return;
  70
  71         ctx->cd_irq = irq;
  72 }
  73 EXPORT_SYMBOL(mmc_gpio_set_cd_irq);
  74
  75 int mmc_gpio_get_ro(struct mmc_host *host)
  76 {
  77         struct mmc_gpio *ctx = host->slot.handler_priv;
  78         int cansleep;
  79
  80         if (!ctx || !ctx->ro_gpio)
  81                 return -ENOSYS;
  82
  83         cansleep = gpiod_cansleep(ctx->ro_gpio);
  84         return cansleep ?
  85                 gpiod_get_value_cansleep(ctx->ro_gpio) :
  86                 gpiod_get_value(ctx->ro_gpio);
  87 }
  88 EXPORT_SYMBOL(mmc_gpio_get_ro);
  89
  90 int mmc_gpio_get_cd(struct mmc_host *host)
  91 {
  92         struct mmc_gpio *ctx = host->slot.handler_priv;
  93         int cansleep;
  94
  95         if (!ctx || !ctx->cd_gpio)
  96                 return -ENOSYS;
  97
  98         cansleep = gpiod_cansleep(ctx->cd_gpio);
  99         return cansleep ?
 100                 gpiod_get_value_cansleep(ctx->cd_gpio) :
 101                 gpiod_get_value(ctx->cd_gpio);
 102 }
 103 EXPORT_SYMBOL(mmc_gpio_get_cd);
 104
 105 void mmc_gpiod_request_cd_irq(struct mmc_host *host)
 106 {
 107         struct mmc_gpio *ctx = host->slot.handler_priv;
 108         int irq = -EINVAL;
 109         int ret;
 110
 111         if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
 112                 return;
 113
 114         /*
 115          * Do not use IRQ if the platform prefers to poll, e.g., because that
 116          * IRQ number is already used by another unit and cannot be shared.
 117          */
 118         if (ctx->cd_irq >= 0)
 119                 irq = ctx->cd_irq;
 120         else if (!(host->caps & MMC_CAP_NEEDS_POLL))
 121                 irq = gpiod_to_irq(ctx->cd_gpio);
 122
 123         if (irq >= 0) {
 124                 if (!ctx->cd_gpio_isr)
 125                         ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
 126                 ret = devm_request_threaded_irq(host->parent, irq,
 127                         NULL, ctx->cd_gpio_isr,
 128                         IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 129                         ctx->cd_label, host);
 130                 if (ret < 0)
 131                         irq = ret;
 132         }
 133
 134         host->slot.cd_irq = irq;
 135
 136         if (irq < 0)
 137                 host->caps |= MMC_CAP_NEEDS_POLL;
 138 }
 139 EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
 140
 141 int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
 142 {
 143         int ret = 0;
 144
 145         if (!(host->caps & MMC_CAP_CD_WAKE) ||
 146             host->slot.cd_irq < 0 ||
 147             on == host->slot.cd_wake_enabled)
 148                 return 0;
 149
 150         if (on) {
 151                 ret = enable_irq_wake(host->slot.cd_irq);
 152                 host->slot.cd_wake_enabled = !ret;
 153         } else {
 154                 disable_irq_wake(host->slot.cd_irq);
 155                 host->slot.cd_wake_enabled = false;
 156         }
 157
 158         return ret;
 159 }
 160 EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
 161
 162 /* Register an alternate interrupt service routine for
 163  * the card-detect GPIO.
 164  */
 165 void mmc_gpio_set_cd_isr(struct mmc_host *host, irq_handler_t isr)
 166 {
 167         struct mmc_gpio *ctx = host->slot.handler_priv;
 168
 169         WARN_ON(ctx->cd_gpio_isr);
 170         ctx->cd_gpio_isr = isr;
 171 }
 172 EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
 173
 174 /**
 175  * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
 176  * @host: mmc host
 177  * @con_id: function within the GPIO consumer
 178  * @idx: index of the GPIO to obtain in the consumer
 179  * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
 180  * @debounce: debounce time in microseconds
 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)
 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         /* Update default label if no con_id provided */
 200         if (!con_id)
 201                 gpiod_set_consumer_name(desc, ctx->cd_label);
 202
 203         if (debounce) {
 204                 ret = gpiod_set_debounce(desc, debounce);
 205                 if (ret < 0)
 206                         ctx->cd_debounce_delay_ms = debounce / 1000;
 207         }
 208
 209         /* override forces default (active-low) polarity ... */
 210         if (override_active_level && !gpiod_is_active_low(desc))
 211                 gpiod_toggle_active_low(desc);
 212
 213         /* ... or active-high */
 214         if (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
 215                 gpiod_toggle_active_low(desc);
 216
 217         ctx->cd_gpio = desc;
 218
 219         return 0;
 220 }
 221 EXPORT_SYMBOL(mmc_gpiod_request_cd);
 222
 223 /**
 224  * mmc_gpiod_set_cd_config - set config for card-detection GPIO
 225  * @host: mmc host
 226  * @config: Generic pinconf config (from pinconf_to_config_packed())
 227  *
 228  * This can be used by mmc host drivers to fixup a card-detection GPIO's config
 229  * (e.g. set PIN_CONFIG_BIAS_PULL_UP) after acquiring the GPIO descriptor
 230  * through mmc_gpiod_request_cd().
 231  *
 232  * Returns:
 233  * 0 on success, or a negative errno value on error.
 234  */
 235 int mmc_gpiod_set_cd_config(struct mmc_host *host, unsigned long config)
 236 {
 237         struct mmc_gpio *ctx = host->slot.handler_priv;
 238
 239         return gpiod_set_config(ctx->cd_gpio, config);
 240 }
 241 EXPORT_SYMBOL(mmc_gpiod_set_cd_config);
 242
 243 bool mmc_can_gpio_cd(struct mmc_host *host)
 244 {
 245         struct mmc_gpio *ctx = host->slot.handler_priv;
 246
 247         return ctx->cd_gpio ? true : false;
 248 }
 249 EXPORT_SYMBOL(mmc_can_gpio_cd);
 250
 251 /**
 252  * mmc_gpiod_request_ro - request a gpio descriptor for write protection
 253  * @host: mmc host
 254  * @con_id: function within the GPIO consumer
 255  * @idx: index of the GPIO to obtain in the consumer
 256  * @debounce: debounce time in microseconds
 257  *
 258  * Returns zero on success, else an error.
 259  */
 260 int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
 261                          unsigned int idx, unsigned int debounce)
 262 {
 263         struct mmc_gpio *ctx = host->slot.handler_priv;
 264         struct gpio_desc *desc;
 265         int ret;
 266
 267         desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
 268         if (IS_ERR(desc))
 269                 return PTR_ERR(desc);
 270
 271         /* Update default label if no con_id provided */
 272         if (!con_id)
 273                 gpiod_set_consumer_name(desc, ctx->ro_label);
 274
 275         if (debounce) {
 276                 ret = gpiod_set_debounce(desc, debounce);
 277                 if (ret < 0)
 278                         return ret;
 279         }
 280
 281         if (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
 282                 gpiod_toggle_active_low(desc);
 283
 284         ctx->ro_gpio = desc;
 285
 286         return 0;
 287 }
 288 EXPORT_SYMBOL(mmc_gpiod_request_ro);
 289
 290 bool mmc_can_gpio_ro(struct mmc_host *host)
 291 {
 292         struct mmc_gpio *ctx = host->slot.handler_priv;
 293
 294         return ctx->ro_gpio ? true : false;
 295 }
 296 EXPORT_SYMBOL(mmc_can_gpio_ro);