[PATCH v2 3/4] mmc: rework cd-gpio handling

From: MichaÅ MirosÅaw
Date: Tue Dec 10 2019 - 21:41:01 EST


There are a few places around the code that invert inverted and possibly
inverted CD line. That's really confusing. Squash them all into one
place in mmc_gpiod_request_cd(). MMC_CAP2_CD_ACTIVE_HIGH is used
analogously to WP line: in GPIO mode it is used only at probe time to
switch polarity, for native mode it is left as is.

Signed-off-by: MichaÅ MirosÅaw <mirq-linux@xxxxxxxxxxxx>
---
drivers/gpio/gpiolib-of.c | 17 -----------------
drivers/mmc/core/host.c | 21 ++++-----------------
drivers/mmc/core/slot-gpio.c | 17 ++++++++---------
3 files changed, 12 insertions(+), 43 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index b0b77e52e261..8310da48ba01 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -104,23 +104,6 @@ static void of_gpio_flags_quirks(struct device_node *np,
enum of_gpio_flags *flags,
int index)
{
- /*
- * Handle MMC "cd-inverted" and "wp-inverted" semantics.
- */
- if (IS_ENABLED(CONFIG_MMC)) {
- /*
- * Active low is the default according to the
- * SDHCI specification and the device tree
- * bindings. However the code in the current
- * kernel was written such that the phandle
- * flags were always respected, and "cd-inverted"
- * would invert the flag from the device phandle.
- */
- if (!strcmp(propname, "cd-gpios")) {
- if (of_property_read_bool(np, "cd-inverted"))
- *flags ^= OF_GPIO_ACTIVE_LOW;
- }
- }
/*
* Some GPIO fixed regulator quirks.
* Note that active low is the default.
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index b3484def0a8b..e655dc1b5b85 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -175,7 +175,6 @@ int mmc_of_parse(struct mmc_host *host)
struct device *dev = host->parent;
u32 bus_width, drv_type, cd_debounce_delay_ms;
int ret;
- bool cd_cap_invert, cd_gpio_invert = false;

if (!dev || !dev_fwnode(dev))
return 0;
@@ -218,10 +217,12 @@ int mmc_of_parse(struct mmc_host *host)
*/

/* Parse Card Detection */
+
if (device_property_read_bool(dev, "non-removable")) {
host->caps |= MMC_CAP_NONREMOVABLE;
} else {
- cd_cap_invert = device_property_read_bool(dev, "cd-inverted");
+ if (device_property_read_bool(dev, "cd-inverted"))
+ host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;

if (device_property_read_u32(dev, "cd-debounce-delay-ms",
&cd_debounce_delay_ms))
@@ -232,25 +233,11 @@ int mmc_of_parse(struct mmc_host *host)

ret = mmc_gpiod_request_cd(host, "cd", 0, false,
cd_debounce_delay_ms * 1000,
- &cd_gpio_invert);
+ NULL);
if (!ret)
dev_info(host->parent, "Got CD GPIO\n");
else if (ret != -ENOENT && ret != -ENOSYS)
return ret;
-
- /*
- * There are two ways to flag that the CD line is inverted:
- * through the cd-inverted flag and by the GPIO line itself
- * being inverted from the GPIO subsystem. This is a leftover
- * from the times when the GPIO subsystem did not make it
- * possible to flag a line as inverted.
- *
- * If the capability on the host AND the GPIO line are
- * both inverted, the end result is that the CD line is
- * not inverted.
- */
- if (cd_cap_invert ^ cd_gpio_invert)
- host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
}

/* Parse Write Protection */
diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
index 582ec3d720f6..303e825ecfd8 100644
--- a/drivers/mmc/core/slot-gpio.c
+++ b/drivers/mmc/core/slot-gpio.c
@@ -19,7 +19,6 @@
struct mmc_gpio {
struct gpio_desc *ro_gpio;
struct gpio_desc *cd_gpio;
- bool override_cd_active_level;
irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
char *ro_label;
char *cd_label;
@@ -80,13 +79,6 @@ int mmc_gpio_get_cd(struct mmc_host *host)
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);
@@ -194,10 +186,17 @@ int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
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);
+
if (gpio_invert)
*gpio_invert = !gpiod_is_active_low(desc);

- ctx->override_cd_active_level = override_active_level;
ctx->cd_gpio = desc;

return 0;
--
2.20.1