gpio: add support of new GPIO direction flag
This commit manages the new dir flags that can be used in gpio
specifiers to indicate the pull-up or pull-down resistor
configuration for output gpio (GPIO_PULL_UP, GPIO_PULL_DOWN)
or the Open Drain/Open Source configuration for input gpio
(GPIO_OPEN_DRAIN, GPIO_OPEN_SOURCE).
These flags are already supported in Linux kernel in gpio lib.
This patch only parse and save the direction flags in GPIO
descriptor (desc->flags), it prepares the introduction of new ops
to manage them.
The GPIO uclass supports new GPIO flags from device-tree
(GPIO_XXX define in include/dt-bindings/gpio/gpio.h)
and translate them in the dir flags (GPIOD_XXX):
- GPIO_PULL_UP => GPIOD_PULL_UP
- GPIO_PULL_DOWN => GPIOD_PULL_DOWN
- GPIO_OPEN_DRAIN => GPIOD_OPEN_DRAIN
- GPIO_OPEN_SOURCE => GPIOD_OPEN_SOURCE
This patch also adds protection in the check_dir_flags function for
new invalid configuration of the dir flags.
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 9550e45..2526399 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -145,6 +145,24 @@
if (args->args[1] & GPIO_ACTIVE_LOW)
desc->flags |= GPIOD_ACTIVE_LOW;
+ /*
+ * need to test 2 bits for gpio output binding:
+ * OPEN_DRAIN (0x6) = SINGLE_ENDED (0x2) | LINE_OPEN_DRAIN (0x4)
+ * OPEN_SOURCE (0x2) = SINGLE_ENDED (0x2) | LINE_OPEN_SOURCE (0x0)
+ */
+ if (args->args[1] & GPIO_SINGLE_ENDED) {
+ if (args->args[1] & GPIO_LINE_OPEN_DRAIN)
+ desc->flags |= GPIOD_OPEN_DRAIN;
+ else
+ desc->flags |= GPIOD_OPEN_SOURCE;
+ }
+
+ if (args->args[1] & GPIO_PULL_UP)
+ desc->flags |= GPIOD_PULL_UP;
+
+ if (args->args[1] & GPIO_PULL_DOWN)
+ desc->flags |= GPIOD_PULL_DOWN;
+
return 0;
}
@@ -521,6 +539,18 @@
return -EINVAL;
}
+ if ((flags & GPIOD_PULL_UP) && (flags & GPIOD_PULL_DOWN)) {
+ log_debug("%s: flags 0x%lx has GPIOD_PULL_UP and GPIOD_PULL_DOWN\n",
+ __func__, flags);
+ return -EINVAL;
+ }
+
+ if ((flags & GPIOD_OPEN_DRAIN) && (flags & GPIOD_OPEN_SOURCE)) {
+ log_debug("%s: flags 0x%lx has GPIOD_OPEN_DRAIN and GPIOD_OPEN_SOURCE\n",
+ __func__, flags);
+ return -EINVAL;
+ }
+
return 0;
}
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 1329d02..42c9ab2 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -119,8 +119,12 @@
unsigned long flags;
#define GPIOD_IS_OUT BIT(1) /* GPIO is an output */
#define GPIOD_IS_IN BIT(2) /* GPIO is an input */
-#define GPIOD_ACTIVE_LOW BIT(3) /* value has active low */
+#define GPIOD_ACTIVE_LOW BIT(3) /* GPIO is active when value is low */
#define GPIOD_IS_OUT_ACTIVE BIT(4) /* set output active */
+#define GPIOD_OPEN_DRAIN BIT(5) /* GPIO is open drain type */
+#define GPIOD_OPEN_SOURCE BIT(6) /* GPIO is open source type */
+#define GPIOD_PULL_UP BIT(7) /* GPIO has pull-up enabled */
+#define GPIOD_PULL_DOWN BIT(8) /* GPIO has pull-down enabled */
uint offset; /* GPIO offset within the device */
/*