mmc: core: Add tunable delay before detecting card after card is inserted
Allow to use tunable delay before detecting card after card is inserted,
which either comes from firmware node, or comes from debounce value
passed on to mmc_gpiod_request_cd(). If the platform doesn't support
debounce, then we fall back to use the debounce period as the delay,
otherwise, it behaves the same as before that a HW debounce(if set) plus
a 200ms hardcode delay before detecting the card.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 64b03d6..da08a17 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -179,7 +179,7 @@
int mmc_of_parse(struct mmc_host *host)
{
struct device *dev = host->parent;
- u32 bus_width, drv_type;
+ u32 bus_width, drv_type, cd_debounce_delay_ms;
int ret;
bool cd_cap_invert, cd_gpio_invert = false;
bool ro_cap_invert, ro_gpio_invert = false;
@@ -230,11 +230,16 @@
} else {
cd_cap_invert = device_property_read_bool(dev, "cd-inverted");
+ if (device_property_read_u32(dev, "cd-debounce-delay-ms",
+ &cd_debounce_delay_ms))
+ cd_debounce_delay_ms = 200;
+
if (device_property_read_bool(dev, "broken-cd"))
host->caps |= MMC_CAP_NEEDS_POLL;
ret = mmc_gpiod_request_cd(host, "cd", 0, true,
- 0, &cd_gpio_invert);
+ cd_debounce_delay_ms,
+ &cd_gpio_invert);
if (!ret)
dev_info(host->parent, "Got CD GPIO\n");
else if (ret != -ENOENT && ret != -ENOSYS)