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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/mmc/core/slot-gpio.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/mmc/core/slot-gpio.c')
-rw-r--r-- | drivers/mmc/core/slot-gpio.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c new file mode 100644 index 000000000..86803a3a0 --- /dev/null +++ b/drivers/mmc/core/slot-gpio.c @@ -0,0 +1,344 @@ +/* + * 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> + +#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; + irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id); + char *ro_label; + u32 cd_debounce_delay_ms; + char cd_label[]; +}; + +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; + + host->trigger_card_event = true; + mmc_detect_change(host, msecs_to_jiffies(ctx->cd_debounce_delay_ms)); + + 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; + ctx->cd_debounce_delay_ms = 200; + 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 cansleep; + + if (!ctx || !ctx->cd_gpio) + return -ENOSYS; + + cansleep = gpiod_cansleep(ctx->cd_gpio); + if (ctx->override_cd_active_level) { + int value = cansleep ? + gpiod_get_raw_value_cansleep(ctx->cd_gpio) : + gpiod_get_raw_value(ctx->cd_gpio); + return !value ^ !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH); + } + + return cansleep ? + gpiod_get_value_cansleep(ctx->cd_gpio) : + gpiod_get_value(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_request_cd_irq(struct mmc_host *host) +{ + struct mmc_gpio *ctx = host->slot.handler_priv; + int irq = -EINVAL; + int ret; + + if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio) + return; + + /* + * Do not use IRQ if the platform prefers to poll, e.g., because that + * IRQ number is already used by another unit and cannot be shared. + */ + if (!(host->caps & MMC_CAP_NEEDS_POLL)) + irq = gpiod_to_irq(ctx->cd_gpio); + + 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; +} +EXPORT_SYMBOL(mmc_gpiod_request_cd_irq); + +int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on) +{ + int ret = 0; + + if (!(host->caps & MMC_CAP_CD_WAKE) || + host->slot.cd_irq < 0 || + on == host->slot.cd_wake_enabled) + return 0; + + if (on) { + ret = enable_irq_wake(host->slot.cd_irq); + host->slot.cd_wake_enabled = !ret; + } else { + disable_irq_wake(host->slot.cd_irq); + host->slot.cd_wake_enabled = false; + } + + return ret; +} +EXPORT_SYMBOL(mmc_gpio_set_cd_wake); + +/* 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) + ctx->cd_debounce_delay_ms = debounce / 1000; + } + + 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); + +bool mmc_can_gpio_ro(struct mmc_host *host) +{ + struct mmc_gpio *ctx = host->slot.handler_priv; + + return ctx->ro_gpio ? true : false; +} +EXPORT_SYMBOL(mmc_can_gpio_ro); |