A simple extension of mmc slot functions add support for CD GPIO polling
for cases, where the GPIO cannot produce interrupts or this is for some
reason not desired.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
---
drivers/mmc/core/slot-gpio.c | 42 +++++++++++++++++++++++++++++-----------
include/linux/mmc/slot-gpio.h | 2 +
2 files changed, 32 insertions(+), 12 deletions(-)
diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
index 11a8ef1..1491fd8 100644
--- a/drivers/mmc/core/slot-gpio.c
+++ b/drivers/mmc/core/slot-gpio.c
@@ -29,6 +29,18 @@ static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
return IRQ_HANDLED;
}
+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_INVERTED_CD);
+}
+EXPORT_SYMBOL(mmc_gpio_get_cd);
+
int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
{
size_t len = strlen(dev_name(host->parent)) + 4;
@@ -36,9 +48,6 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
int irq = gpio_to_irq(gpio);
int ret;
- if (irq < 0)
- return irq;
-
ctx = kmalloc(sizeof(*ctx) + len, GFP_KERNEL);
if (!ctx)
return -ENOMEM;
@@ -49,20 +58,25 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
if (ret < 0)
goto egpioreq;
- ret = request_threaded_irq(irq, NULL, mmc_gpio_cd_irqt,
- IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
- ctx->cd_label, host);
- if (ret < 0)
- goto eirqreq;
+ /*
+ * 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 (host->caps & MMC_CAP_NEEDS_POLL || irq < 0) {
+ host->caps |= MMC_CAP_NEEDS_POLL;
+ host->slot.cd_irq = -EINVAL;
+ } else if (!request_threaded_irq(irq, NULL, mmc_gpio_cd_irqt,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ ctx->cd_label, host)) {
+ host->slot.cd_irq = irq;
+ }
ctx->cd_gpio = gpio;
- host->slot.cd_irq = irq;
host->slot.handler_priv = ctx;
return 0;
-eirqreq:
- gpio_free(gpio);
egpioreq:
kfree(ctx);
return ret;
@@ -76,8 +90,12 @@ void mmc_gpio_free_cd(struct mmc_host *host)
if (!ctx)
return;
- free_irq(host->slot.cd_irq, host);
+ if (host->slot.cd_irq >= 0) {
+ free_irq(host->slot.cd_irq, host);
+ host->slot.cd_irq = -EINVAL;
+ }
gpio_free(ctx->cd_gpio);
+ host->slot.handler_priv = NULL;
kfree(ctx);
}
EXPORT_SYMBOL(mmc_gpio_free_cd);
diff --git a/include/linux/mmc/slot-gpio.h b/include/linux/mmc/slot-gpio.h
index edfaa32..1a977d7 100644
--- a/include/linux/mmc/slot-gpio.h
+++ b/include/linux/mmc/slot-gpio.h
@@ -12,6 +12,8 @@
#define MMC_SLOT_GPIO_H
struct mmc_host;
+
+int mmc_gpio_get_cd(struct mmc_host *host);
int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio);
void mmc_gpio_free_cd(struct mmc_host *host);
--
1.7.2.5
--
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