/* * Generic GPIO card-detect helper * * Copyright (C) 2011, Guennadi Liakhovetski * * 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 #include #include #include #include #include #include #include #include #include #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; bool status; 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; struct mmc_gpio *ctx = host->slot.handler_priv; bool status; status = mmc_gpio_get_cd(host) ? true : false; if (status ^ ctx->status) { pr_err("%s: slot status change detected (%d -> %d), GPIO_ACTIVE_%s\n", mmc_hostname(host), ctx->status, status, (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH) ? "HIGH" : "LOW"); ctx->status = status; host->trigger_card_event = true; if (host->card_detect_cnt < 0x7FFFFFFF) host->card_detect_cnt++; 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; int ret; if (host->extcon) { ret = extcon_get_state(host->extcon, EXTCON_MECHANICAL); if (ret < 0) dev_err(mmc_dev(host), "%s: Extcon failed to check card state, ret=%d\n", __func__, ret); return ret; } 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_free_cd_irq(struct mmc_host *host) { devm_free_irq(host->parent, host->slot.cd_irq, host); } EXPORT_SYMBOL(mmc_gpiod_free_cd_irq); void mmc_gpiod_restore_cd_irq(struct mmc_host *host) { struct mmc_gpio *ctx = host->slot.handler_priv; int irq = host->slot.cd_irq; if (irq >= 0) { devm_request_threaded_irq(host->parent, irq, NULL, ctx->cd_gpio_isr, IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, ctx->cd_label, host); } } EXPORT_SYMBOL(mmc_gpiod_restore_cd_irq); 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; ret = mmc_gpio_get_cd(host); if(ret < 0) { pr_err("%s: getting card detection gpio failed \n", mmc_hostname(host)); return; } ctx->status = ret ? true : false; 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; else if ((host->caps & MMC_CAP_CD_WAKE) && !enable_irq_wake(irq)) host->slot.cd_wake_enabled = true; } EXPORT_SYMBOL(mmc_gpiod_request_cd_irq); /** * mmc_gpiod_update_status - update ctx->status to current status * @host: mmc_host * @present: current status from get_cd() * * It is to update card detection status. */ void mmc_gpiod_update_status(struct mmc_host *host, int present) { struct mmc_gpio *ctx = host->slot.handler_priv; bool ctx_status; if (present < 0) return; ctx_status = !!present; if (ctx && (ctx->status ^ ctx_status)) ctx->status = ctx_status; } EXPORT_SYMBOL(mmc_gpiod_update_status); static int mmc_card_detect_notifier(struct notifier_block *nb, unsigned long event, void *ptr) { struct mmc_host *host = container_of(nb, struct mmc_host, card_detect_nb); host->trigger_card_event = true; mmc_detect_change(host, 0); return NOTIFY_DONE; } void mmc_register_extcon(struct mmc_host *host) { struct extcon_dev *extcon = host->extcon; int err; if (!extcon) return; host->card_detect_nb.notifier_call = mmc_card_detect_notifier; err = extcon_register_notifier(extcon, EXTCON_MECHANICAL, &host->card_detect_nb); if (err) { dev_err(mmc_dev(host), "%s: extcon_register_notifier() failed ret=%d\n", __func__, err); host->caps |= MMC_CAP_NEEDS_POLL; } } EXPORT_SYMBOL(mmc_register_extcon); void mmc_unregister_extcon(struct mmc_host *host) { struct extcon_dev *extcon = host->extcon; int err; if (!extcon) return; err = extcon_unregister_notifier(extcon, EXTCON_MECHANICAL, &host->card_detect_nb); if (err) dev_err(mmc_dev(host), "%s: extcon_unregister_notifier() failed ret=%d\n", __func__, err); } EXPORT_SYMBOL(mmc_unregister_extcon); /* 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; 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); bool mmc_can_gpio_cd(struct mmc_host *host) { struct mmc_gpio *ctx = host->slot.handler_priv; return ctx->cd_gpio ? true : false; } EXPORT_SYMBOL(mmc_can_gpio_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; 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);