| /* |
| * 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/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 { |
| int ro_gpio; |
| int cd_gpio; |
| 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 */ |
| mmc_detect_change(dev_id, msecs_to_jiffies(100)); |
| 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)); |
| ctx->cd_gpio = -EINVAL; |
| ctx->ro_gpio = -EINVAL; |
| 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 || !gpio_is_valid(ctx->ro_gpio)) |
| return -ENOSYS; |
| |
| return !gpio_get_value_cansleep(ctx->ro_gpio) ^ |
| !!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH); |
| } |
| 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 || !gpio_is_valid(ctx->cd_gpio)) |
| return -ENOSYS; |
| |
| return !gpio_get_value_cansleep(ctx->cd_gpio) ^ |
| !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH); |
| } |
| EXPORT_SYMBOL(mmc_gpio_get_cd); |
| |
| 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; |
| |
| return gpio_request_one(gpio, GPIOF_DIR_IN, ctx->ro_label); |
| } |
| EXPORT_SYMBOL(mmc_gpio_request_ro); |
| |
| int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio) |
| { |
| struct mmc_gpio *ctx; |
| int irq = gpio_to_irq(gpio); |
| int ret; |
| |
| ret = mmc_gpio_alloc(host); |
| if (ret < 0) |
| return ret; |
| |
| ctx = host->slot.handler_priv; |
| |
| ret = gpio_request_one(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; |
| |
| /* |
| * Even if gpio_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 = request_threaded_irq(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; |
| |
| ctx->cd_gpio = gpio; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(mmc_gpio_request_cd); |
| |
| void mmc_gpio_free_ro(struct mmc_host *host) |
| { |
| struct mmc_gpio *ctx = host->slot.handler_priv; |
| int gpio; |
| |
| if (!ctx || !gpio_is_valid(ctx->ro_gpio)) |
| return; |
| |
| gpio = ctx->ro_gpio; |
| ctx->ro_gpio = -EINVAL; |
| |
| gpio_free(gpio); |
| } |
| EXPORT_SYMBOL(mmc_gpio_free_ro); |
| |
| void mmc_gpio_free_cd(struct mmc_host *host) |
| { |
| struct mmc_gpio *ctx = host->slot.handler_priv; |
| int gpio; |
| |
| if (!ctx || !gpio_is_valid(ctx->cd_gpio)) |
| return; |
| |
| if (host->slot.cd_irq >= 0) { |
| free_irq(host->slot.cd_irq, host); |
| host->slot.cd_irq = -EINVAL; |
| } |
| |
| gpio = ctx->cd_gpio; |
| ctx->cd_gpio = -EINVAL; |
| |
| gpio_free(gpio); |
| } |
| EXPORT_SYMBOL(mmc_gpio_free_cd); |