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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Generic GPIO card-detect helper4 *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 19struct 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 29static 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 41int 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 64void 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}73EXPORT_SYMBOL(mmc_gpio_set_cd_irq);74 75int 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}88EXPORT_SYMBOL(mmc_gpio_get_ro);89 90int 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}103EXPORT_SYMBOL(mmc_gpio_get_cd);104 105void 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 that116 * 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}139EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);140 141int 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}160EXPORT_SYMBOL(mmc_gpio_set_cd_wake);161 162/* Register an alternate interrupt service routine for163 * the card-detect GPIO.164 */165void 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}172EXPORT_SYMBOL(mmc_gpio_set_cd_isr);173 174/**175 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection176 * @host: mmc host177 * @con_id: function within the GPIO consumer178 * @idx: index of the GPIO to obtain in the consumer179 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag180 * @debounce: debounce time in microseconds181 *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 */187int 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}221EXPORT_SYMBOL(mmc_gpiod_request_cd);222 223/**224 * mmc_gpiod_set_cd_config - set config for card-detection GPIO225 * @host: mmc host226 * @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 config229 * (e.g. set PIN_CONFIG_BIAS_PULL_UP) after acquiring the GPIO descriptor230 * through mmc_gpiod_request_cd().231 *232 * Returns:233 * 0 on success, or a negative errno value on error.234 */235int 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}241EXPORT_SYMBOL(mmc_gpiod_set_cd_config);242 243bool 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}249EXPORT_SYMBOL(mmc_can_gpio_cd);250 251/**252 * mmc_gpiod_request_ro - request a gpio descriptor for write protection253 * @host: mmc host254 * @con_id: function within the GPIO consumer255 * @idx: index of the GPIO to obtain in the consumer256 * @debounce: debounce time in microseconds257 *258 * Returns zero on success, else an error.259 */260int 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}288EXPORT_SYMBOL(mmc_gpiod_request_ro);289 290bool 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}296EXPORT_SYMBOL(mmc_can_gpio_ro);297