[U-Boot] [PATCH v2 08/14] gpio: add ops for configuration with dir flags
Patrick Delaunay
patrick.delaunay at st.com
Tue Nov 26 08:49:05 UTC 2019
This commit manages the dir flags that can be used in gpio specifiers
to indicate if a pull-up resistor or pull-down resistor should be
enabled for output gpio (GPIO_PULL_UP, GPIO_PULL_DOWN) and the
Open Drain/Open Source configuration for input gpio
(GPIO_OPEN_DRAIN, GPIO_OPEN_SOURCE).
These flags are already supported in Linux kernel in gpiolib;
this patch provides the same support in U-Boot.
The dir flags are managed in gpio drivers with two optional ops in gpio
uclass: set_dir_flags and get_dir_flags.
- ops set_dir_flags() set the direction and configuration of each GPIO
with a only call to dm_gpio_set_dir_flags() / dm_gpio_set_dir()
and respecting the configuration provided by device tree
(saved in desc->flags).
- ops get_dir_flags() return dynamically the current gpio configuration,
it is used by the new API dm_gpio_get_dir_flags().
When these optional ops are absent, the gpio uclass use the mandatory ops
(direction_output, direction_input, get_value) and desc->flags to manage
only the main dir flags:
- GPIOD_IS_IN
- GPIOD_IS_OUT
- GPIOD_IS_OUT_ACTIVE
- GPIOD_ACTIVE_LOW
Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
---
Changes in v2:
- change the proposed ops for pin config to set_dir_flags/get_dir_flags
- reused the existing API dm_gpio_set_dir_flags/dm_gpio_set_dir
- add a new API dm_gpio_get_dir_flags
drivers/gpio/gpio-uclass.c | 157 +++++++++++++++++++++++++++++++------
include/asm-generic/gpio.h | 65 +++++++++++++--
2 files changed, 192 insertions(+), 30 deletions(-)
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 0870458e96..241293f4b4 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -140,8 +140,27 @@ int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
if (args->args_count < 2)
return 0;
+ desc->flags = 0;
if (args->args[1] & GPIO_ACTIVE_LOW)
- desc->flags = GPIOD_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;
}
@@ -476,18 +495,24 @@ int gpio_direction_output(unsigned gpio, int value)
desc.offset, value);
}
-int dm_gpio_get_value(const struct gpio_desc *desc)
+static int _gpio_get_value(const struct gpio_desc *desc)
{
int value;
+
+ value = gpio_get_ops(desc->dev)->get_value(desc->dev, desc->offset);
+
+ return desc->flags & GPIOD_ACTIVE_LOW ? !value : value;
+}
+
+int dm_gpio_get_value(const struct gpio_desc *desc)
+{
int ret;
ret = check_reserved(desc, "get_value");
if (ret)
return ret;
- value = gpio_get_ops(desc->dev)->get_value(desc->dev, desc->offset);
-
- return desc->flags & GPIOD_ACTIVE_LOW ? !value : value;
+ return _gpio_get_value(desc);
}
int dm_gpio_set_value(const struct gpio_desc *desc, int value)
@@ -504,39 +529,119 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value)
return 0;
}
-int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
+/* check dir flags invalid configuration */
+static int check_dir_flags(ulong flags)
+{
+ if ((flags & GPIOD_IS_OUT) && (flags & GPIOD_IS_IN))
+ return -EINVAL;
+
+ if ((flags & GPIOD_PULL_UP) && (flags & GPIOD_PULL_DOWN))
+ return -EINVAL;
+
+ if ((flags & GPIOD_OPEN_DRAIN) && (flags & GPIOD_OPEN_SOURCE))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int _dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
{
struct udevice *dev = desc->dev;
struct dm_gpio_ops *ops = gpio_get_ops(dev);
+ struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
int ret;
- ret = check_reserved(desc, "set_dir");
- if (ret)
- return ret;
+ ret = check_dir_flags(flags);
+ if (ret) {
+ dev_err(dev,
+ "%s error: set_dir_flags for gpio %s%d has invalid dir flags 0x%lx\n",
+ desc->dev->name,
+ uc_priv->bank_name ? uc_priv->bank_name : "",
+ desc->offset, flags);
- if (flags & GPIOD_IS_OUT) {
- int value = flags & GPIOD_IS_OUT_ACTIVE ? 1 : 0;
+ return ret;
+ }
- if (flags & GPIOD_ACTIVE_LOW)
- value = !value;
- ret = ops->direction_output(dev, desc->offset, value);
- } else if (flags & GPIOD_IS_IN) {
- ret = ops->direction_input(dev, desc->offset);
+ /* GPIOD_ are directly managed by driver in set_dir_flags*/
+ if (ops->set_dir_flags) {
+ ret = ops->set_dir_flags(dev, desc->offset, flags);
+ } else {
+ if (flags & GPIOD_IS_OUT) {
+ ret = ops->direction_output(dev, desc->offset,
+ GPIOD_FLAGS_OUTPUT(flags));
+ } else if (flags & GPIOD_IS_IN) {
+ ret = ops->direction_input(dev, desc->offset);
+ }
}
+
+ return ret;
+}
+
+int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
+{
+ int ret;
+
+ ret = check_reserved(desc, "set_dir_flags");
if (ret)
return ret;
- /*
- * Update desc->flags here, so that GPIO_ACTIVE_LOW is honoured in
- * futures
- */
- desc->flags = flags;
- return 0;
+ /* combine the requested flags (for IN/OUT) and the descriptor flags */
+ flags |= desc->flags;
+ ret = _dm_gpio_set_dir_flags(desc, flags);
+
+ /* update the descriptor flags */
+ if (ret)
+ desc->flags = flags;
+
+ return ret;
}
int dm_gpio_set_dir(struct gpio_desc *desc)
{
- return dm_gpio_set_dir_flags(desc, desc->flags);
+ int ret;
+
+ ret = check_reserved(desc, "set_dir");
+ if (ret)
+ return ret;
+
+ return _dm_gpio_set_dir_flags(desc, desc->flags);
+}
+
+int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags)
+{
+ struct udevice *dev = desc->dev;
+ struct dm_gpio_ops *ops = gpio_get_ops(dev);
+ int ret, value;
+ ulong dir_flags;
+
+ ret = check_reserved(desc, "get_dir_flags");
+ if (ret)
+ return ret;
+
+ /* GPIOD_ are directly provided by driver except GPIOD_ACTIVE_LOW*/
+ if (ops->get_dir_flags) {
+ ret = ops->get_dir_flags(dev, desc->offset, &dir_flags);
+ if (ret)
+ return ret;
+
+ /* GPIOD_ACTIVE_LOW is saved in desc->flags */
+ value = dir_flags & GPIOD_IS_OUT_ACTIVE ? 1 : 0;
+ if (desc->flags & GPIOD_ACTIVE_LOW)
+ value = !value;
+ dir_flags &= ~(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE);
+ dir_flags |= (desc->flags & GPIOD_ACTIVE_LOW);
+ if (value)
+ dir_flags |= GPIOD_IS_OUT_ACTIVE;
+ } else {
+ dir_flags = desc->flags;
+ /* only GPIOD_IS_OUT_ACTIVE is provided by uclass */
+ dir_flags &= ~GPIOD_IS_OUT_ACTIVE;
+ if ((desc->flags & GPIOD_IS_OUT) && _gpio_get_value(desc))
+ dir_flags |= GPIOD_IS_OUT_ACTIVE;
+ }
+ *flags = dir_flags;
+
+ return 0;
}
/**
@@ -809,7 +914,7 @@ static int gpio_request_tail(int ret, const char *nodename,
debug("%s: dm_gpio_requestf failed\n", __func__);
goto err;
}
- ret = dm_gpio_set_dir_flags(desc, flags | desc->flags);
+ ret = dm_gpio_set_dir_flags(desc, flags);
if (ret) {
debug("%s: dm_gpio_set_dir failed\n", __func__);
goto err;
@@ -1036,6 +1141,10 @@ static int gpio_post_bind(struct udevice *dev)
ops->get_function += gd->reloc_off;
if (ops->xlate)
ops->xlate += gd->reloc_off;
+ if (ops->set_dir_flags)
+ ops->set_dir_flags += gd->reloc_off;
+ if (ops->get_dir_flags)
+ ops->get_dir_flags += gd->reloc_off;
reloc_done++;
}
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 454578c8d2..c6991be1c9 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -117,10 +117,15 @@ struct udevice;
struct gpio_desc {
struct udevice *dev; /* Device, NULL for invalid GPIO */
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_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 */
/*
@@ -129,6 +134,12 @@ struct gpio_desc {
*/
};
+/* helper to compute the value of the gpio output */
+#define GPIOD_FLAGS_OUTPUT_MASK (GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE)
+#define GPIOD_FLAGS_OUTPUT(flags) \
+ (((((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_IS_OUT_ACTIVE) || \
+ (((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_ACTIVE_LOW)) ? 1 : 0)
+
/**
* dm_gpio_is_valid() - Check if a GPIO is valid
*
@@ -253,6 +264,7 @@ struct dm_gpio_ops {
int value);
int (*get_value)(struct udevice *dev, unsigned offset);
int (*set_value)(struct udevice *dev, unsigned offset, int value);
+
/**
* get_function() Get the GPIO function
*
@@ -287,6 +299,37 @@ struct dm_gpio_ops {
*/
int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
struct ofnode_phandle_args *args);
+
+ /**
+ * set_dir_flags() - Set GPIO dir flags
+ *
+ * This function should set up the GPIO configuration according to the
+ * information provide by the direction flags bitfield.
+ *
+ * This method is optional.
+ *
+ * @dev: GPIO device
+ * @offset: GPIO offset within that device
+ * @flags: GPIO configuration to use
+ * @return 0 if OK, -ve on error
+ */
+ int (*set_dir_flags)(struct udevice *dev, unsigned int offset,
+ ulong flags);
+
+ /**
+ * get_dir_flags() - Get GPIO dir flags
+ *
+ * This function return the GPIO direction flags used.
+ *
+ * This method is optional.
+ *
+ * @dev: GPIO device
+ * @offset: GPIO offset within that device
+ * @flags: place to put the used direction flags by GPIO
+ * @return 0 if OK, -ve on error
+ */
+ int (*get_dir_flags)(struct udevice *dev, unsigned int offset,
+ ulong *flags);
};
/**
@@ -586,8 +629,7 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value);
/**
* dm_gpio_set_dir() - Set the direction for a GPIO
*
- * This sets up the direction according tot the provided flags. It will do
- * nothing unless the direction is actually specified.
+ * This sets up the direction according to the GPIO flags: desc->flags.
*
* @desc: GPIO description containing device, offset and flags,
* previously returned by gpio_request_by_name()
@@ -596,11 +638,10 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value);
int dm_gpio_set_dir(struct gpio_desc *desc);
/**
- * dm_gpio_set_dir_flags() - Set direction using specific flags
+ * dm_gpio_set_dir_flags() - Set direction using add flags
*
- * This is like dm_gpio_set_dir() except that the flags value is provided
- * instead of being used from desc->flags. This is needed because in many
- * cases the GPIO description does not include direction information.
+ * This sets up the direction according tot the provided flags and the GPIO
+ * description (desc->flags) which include direction information.
* Note that desc->flags is updated by this function.
*
* @desc: GPIO description containing device, offset and flags,
@@ -610,6 +651,18 @@ int dm_gpio_set_dir(struct gpio_desc *desc);
*/
int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
+/**
+ * dm_gpio_get_dir_flags() - Get direction flags
+ *
+ * read the current direction flags
+ *
+ * @desc: GPIO description containing device, offset and flags,
+ * previously returned by gpio_request_by_name()
+ * @flags: place to put the used flags
+ * @return 0 if OK, -ve on error, in which case desc->flags is not updated
+ */
+int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags);
+
/**
* gpio_get_number() - Get the global GPIO number of a GPIO
*
--
2.17.1
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