| /* |
| * Generic GPIO card-detect helper |
| * |
| * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de> |
| * |
| * 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 <linux/err.h> |
| #include <linux/gpio.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/interrupt.h> |
| #include <linux/jiffies.h> |
| #include <linux/mmc/host.h> |
| #include <linux/mmc/slot-gpio.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| |
| struct mmc_gpio { |
| struct gpio_desc *ro_gpio; |
| struct gpio_desc *cd_gpio; |
| bool override_ro_active_level; |
| bool override_cd_active_level; |
| 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; |
| |
| host->trigger_card_event = true; |
| mmc_detect_change(host, msecs_to_jiffies(200)); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int mmc_gpio_alloc(struct mmc_host *host) |
| { |
| size_t len = strlen(dev_name(host->parent)) + 4; |
| struct mmc_gpio *ctx; |
| |
| mutex_lock(&host->slot.lock); |
| |
| ctx = host->slot.handler_priv; |
| if (!ctx) { |
| /* |
| * devm_kzalloc() can be called after device_initialize(), even |
| * before device_add(), i.e., between mmc_alloc_host() and |
| * mmc_add_host() |
| */ |
| ctx = devm_kzalloc(&host->class_dev, 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; |
| } |
| } |
| |
| mutex_unlock(&host->slot.lock); |
| |
| 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; |
| |
| 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 explicitly call mmc_gpio_free_ro() for freeing up, |
| * if the requesting and freeing are only needed at probing and unbinding time |
| * for once. However, if client drivers do something special like runtime |
| * switching for write-protection, they are responsible for calling |
| * mmc_gpio_request_ro() and mmc_gpio_free_ro() as a pair on their own. |
| * |
| * Returns zero on success, else an error. |
| */ |
| int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio) |
| { |
| struct mmc_gpio *ctx; |
| int ret; |
| |
| if (!gpio_is_valid(gpio)) |
| return -EINVAL; |
| |
| ret = mmc_gpio_alloc(host); |
| if (ret < 0) |
| return ret; |
| |
| ctx = host->slot.handler_priv; |
| |
| ret = devm_gpio_request_one(&host->class_dev, 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_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; |
| |
| if (irq >= 0) { |
| ret = devm_request_threaded_irq(&host->class_dev, irq, |
| NULL, mmc_gpio_cd_irqt, |
| 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; |
| } |
| EXPORT_SYMBOL(mmc_gpiod_request_cd_irq); |
| |
| /** |
| * 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 explicitly call mmc_gpio_free_cd() for freeing up, |
| * if the requesting and freeing are only needed at probing and unbinding time |
| * for once. However, if client drivers do something special like runtime |
| * switching for card-detection, they are responsible for calling |
| * mmc_gpio_request_cd() and mmc_gpio_free_cd() as a pair on their own. |
| * |
| * 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; |
| int ret; |
| |
| ret = mmc_gpio_alloc(host); |
| if (ret < 0) |
| return ret; |
| |
| ctx = host->slot.handler_priv; |
| |
| ret = devm_gpio_request_one(&host->class_dev, 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_gpio_free_ro - free the write-protection gpio |
| * @host: mmc host |
| * |
| * It's provided only for cases that client drivers need to manually free |
| * up the write-protection gpio requested by mmc_gpio_request_ro(). |
| */ |
| void mmc_gpio_free_ro(struct mmc_host *host) |
| { |
| struct mmc_gpio *ctx = host->slot.handler_priv; |
| int gpio; |
| |
| if (!ctx || !ctx->ro_gpio) |
| return; |
| |
| gpio = desc_to_gpio(ctx->ro_gpio); |
| ctx->ro_gpio = NULL; |
| |
| devm_gpio_free(&host->class_dev, gpio); |
| } |
| EXPORT_SYMBOL(mmc_gpio_free_ro); |
| |
| /** |
| * mmc_gpio_free_cd - free the card-detection gpio |
| * @host: mmc host |
| * |
| * It's provided only for cases that client drivers need to manually free |
| * up the card-detection gpio requested by mmc_gpio_request_cd(). |
| */ |
| void mmc_gpio_free_cd(struct mmc_host *host) |
| { |
| struct mmc_gpio *ctx = host->slot.handler_priv; |
| int gpio; |
| |
| if (!ctx || !ctx->cd_gpio) |
| return; |
| |
| if (host->slot.cd_irq >= 0) { |
| devm_free_irq(&host->class_dev, host->slot.cd_irq, host); |
| host->slot.cd_irq = -EINVAL; |
| } |
| |
| gpio = desc_to_gpio(ctx->cd_gpio); |
| ctx->cd_gpio = NULL; |
| |
| devm_gpio_free(&host->class_dev, gpio); |
| } |
| EXPORT_SYMBOL(mmc_gpio_free_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 |
| * |
| * Use this function in place of mmc_gpio_request_cd() to use the GPIO |
| * descriptor API. Note that it is paired with mmc_gpiod_free_cd() not |
| * mmc_gpio_free_cd(). Note also 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) |
| { |
| struct mmc_gpio *ctx; |
| struct gpio_desc *desc; |
| int ret; |
| |
| ret = mmc_gpio_alloc(host); |
| if (ret < 0) |
| return ret; |
| |
| ctx = host->slot.handler_priv; |
| |
| if (!con_id) |
| con_id = ctx->cd_label; |
| |
| 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; |
| } |
| |
| ctx->override_cd_active_level = override_active_level; |
| ctx->cd_gpio = desc; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(mmc_gpiod_request_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 |
| * |
| * Use this function in place of mmc_gpio_request_ro() to use the GPIO |
| * descriptor API. Note that it is paired with mmc_gpiod_free_ro() not |
| * mmc_gpio_free_ro(). |
| * |
| * 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) |
| { |
| struct mmc_gpio *ctx; |
| struct gpio_desc *desc; |
| int ret; |
| |
| ret = mmc_gpio_alloc(host); |
| if (ret < 0) |
| return ret; |
| |
| ctx = host->slot.handler_priv; |
| |
| if (!con_id) |
| con_id = ctx->ro_label; |
| |
| 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; |
| } |
| |
| ctx->override_ro_active_level = override_active_level; |
| ctx->ro_gpio = desc; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(mmc_gpiod_request_ro); |
| |
| /** |
| * mmc_gpiod_free_cd - free the card-detection gpio descriptor |
| * @host: mmc host |
| * |
| * It's provided only for cases that client drivers need to manually free |
| * up the card-detection gpio requested by mmc_gpiod_request_cd(). |
| */ |
| void mmc_gpiod_free_cd(struct mmc_host *host) |
| { |
| struct mmc_gpio *ctx = host->slot.handler_priv; |
| |
| if (!ctx || !ctx->cd_gpio) |
| return; |
| |
| if (host->slot.cd_irq >= 0) { |
| devm_free_irq(&host->class_dev, host->slot.cd_irq, host); |
| host->slot.cd_irq = -EINVAL; |
| } |
| |
| devm_gpiod_put(&host->class_dev, ctx->cd_gpio); |
| |
| ctx->cd_gpio = NULL; |
| } |
| EXPORT_SYMBOL(mmc_gpiod_free_cd); |