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path: root/drivers/mmc/core/slot-gpio.c
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Diffstat (limited to 'drivers/mmc/core/slot-gpio.c')
-rw-r--r--drivers/mmc/core/slot-gpio.c250
1 files changed, 250 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..05e907451
--- /dev/null
+++ b/drivers/mmc/core/slot-gpio.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Generic GPIO card-detect helper
+ *
+ * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ */
+
+#include <linux/err.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;
+ irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
+ char *ro_label;
+ char *cd_label;
+ u32 cd_debounce_delay_ms;
+};
+
+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)
+{
+ struct mmc_gpio *ctx = devm_kzalloc(host->parent,
+ sizeof(*ctx), GFP_KERNEL);
+
+ if (ctx) {
+ ctx->cd_debounce_delay_ms = 200;
+ ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL,
+ "%s cd", dev_name(host->parent));
+ if (!ctx->cd_label)
+ return -ENOMEM;
+ ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL,
+ "%s ro", dev_name(host->parent));
+ if (!ctx->ro_label)
+ return -ENOMEM;
+ 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;
+
+ 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);
+ return cansleep ?
+ gpiod_get_value_cansleep(ctx->cd_gpio) :
+ gpiod_get_value(ctx->cd_gpio);
+}
+EXPORT_SYMBOL(mmc_gpio_get_cd);
+
+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_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
+ *
+ * Note that this 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 = 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;
+ }
+
+ /* override forces default (active-low) polarity ... */
+ if (override_active_level && !gpiod_is_active_low(desc))
+ gpiod_toggle_active_low(desc);
+
+ /* ... or active-high */
+ if (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
+ gpiod_toggle_active_low(desc);
+
+ 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
+ * @debounce: debounce time in microseconds
+ *
+ * Returns zero on success, else an error.
+ */
+int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
+ unsigned int idx, unsigned int debounce)
+{
+ 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 (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
+ gpiod_toggle_active_low(desc);
+
+ 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 03:33:34 +0000