/*
* Generic GPIO API for U-Boot
*
+ * --
+ * NB: This is deprecated. Please use the driver model functions instead:
+ *
+ * - gpio_request_by_name()
+ * - dm_gpio_get_value() etc.
+ *
+ * For now we need a dm_ prefix on some functions to avoid name collision.
+ * --
+ *
* GPIOs are numbered from 0 to GPIO_COUNT-1 which value is defined
* by the SOC/architecture.
*
};
/**
+ * @deprecated Please use driver model instead
* Request a GPIO. This should be called before any of the other functions
* are used on this GPIO.
*
int gpio_request(unsigned gpio, const char *label);
/**
+ * @deprecated Please use driver model instead
* Request a GPIO and configure it
* @param gpios pointer to array of gpio defs
* @param count number of GPIOs to set up
int gpio_request_array(const struct gpio *gpios, int count);
/**
+ * @deprecated Please use driver model instead
* Stop using the GPIO. This function should not alter pin configuration.
*
* @param gpio GPIO number
int gpio_free(unsigned gpio);
/**
+ * @deprecated Please use driver model instead
* Release a set of GPIOs
* @param gpios pointer to array of gpio defs
* @param count number of GPIOs to set up
int gpio_free_array(const struct gpio *gpios, int count);
/**
+ * @deprecated Please use driver model instead
* Make a GPIO an input.
*
* @param gpio GPIO number
int gpio_direction_input(unsigned gpio);
/**
+ * @deprecated Please use driver model instead
* Make a GPIO an output, and set its value.
*
* @param gpio GPIO number
int gpio_direction_output(unsigned gpio, int value);
/**
+ * @deprecated Please use driver model instead
* Get a GPIO's value. This will work whether the GPIO is an input
* or an output.
*
int gpio_get_value(unsigned gpio);
/**
+ * @deprecated Please use driver model instead
* Set an output GPIO's value. The GPIO must already be an output or
* this function may have no effect.
*
struct udevice;
+struct gpio_desc {
+ struct udevice *dev; /* Device, NULL for invalid GPIO */
+ unsigned long flags;
+#define GPIOD_REQUESTED (1 << 0) /* Requested/claimed */
+#define GPIOD_IS_OUT (1 << 1) /* GPIO is an output */
+#define GPIOD_IS_IN (1 << 2) /* GPIO is an output */
+#define GPIOD_ACTIVE_LOW (1 << 3) /* value has active low */
+#define GPIOD_IS_OUT_ACTIVE (1 << 4) /* set output active */
+
+ uint offset; /* GPIO offset within the device */
+ /*
+ * We could consider adding the GPIO label in here. Possibly we could
+ * use this structure for internal GPIO information.
+ */
+};
+
+/**
+ * dm_gpio_is_valid() - Check if a GPIO is gpio_is_valie
+ *
+ * @desc: GPIO description containing device, offset and flags,
+ * previously returned by gpio_request_by_name()
+ * @return true if valid, false if not
+ */
+static inline bool dm_gpio_is_valid(struct gpio_desc *desc)
+{
+ return desc->dev != NULL;
+}
+
/**
* gpio_get_status() - get the current GPIO status as a string
*
* which means this is GPIO bank b, offset 4, currently set to input, current
* value 1, [x] means that it is requested and the owner is 'sdmmc_cd'
*
+ * TODO(sjg@chromium.org): This should use struct gpio_desc
+ *
* @dev: Device to check
* @offset: Offset of device GPIO to check
* @buf: Place to put string
*
* Note this returns GPIOF_UNUSED if the GPIO is not requested.
*
+ * TODO(sjg@chromium.org): This should use struct gpio_desc
+ *
* @dev: Device to check
* @offset: Offset of device GPIO to check
* @namep: If non-NULL, this is set to the nane given when the GPIO
* Note this does not return GPIOF_UNUSED - it will always return the GPIO
* driver's view of a pin function, even if it is not correctly set up.
*
+ * TODO(sjg@chromium.org): This should use struct gpio_desc
+ *
* @dev: Device to check
* @offset: Offset of device GPIO to check
* @namep: If non-NULL, this is set to the nane given when the GPIO
int gpio_requestf(unsigned gpio, const char *fmt, ...)
__attribute__ ((format (__printf__, 2, 3)));
+struct fdtdec_phandle_args;
+
/**
* struct struct dm_gpio_ops - Driver model GPIO operations
*
* @return current function - GPIOF_...
*/
int (*get_function)(struct udevice *dev, unsigned offset);
+
+ /**
+ * xlate() - Translate phandle arguments into a GPIO description
+ *
+ * This function should set up the fields in desc according to the
+ * information in the arguments. The uclass will have set up:
+ *
+ * @desc->dev to @dev
+ * @desc->flags to 0
+ * @desc->offset to the value of the first argument in args, if any,
+ * otherwise -1 (which is invalid)
+ *
+ * This method is optional so if the above defaults suit it can be
+ * omitted. Typical behaviour is to set up the GPIOD_ACTIVE_LOW flag
+ * in desc->flags.
+ *
+ * Note that @dev is passed in as a parameter to follow driver model
+ * uclass conventions, even though it is already available as
+ * desc->dev.
+ *
+ * @dev: GPIO device
+ * @desc: Place to put GPIO description
+ * @args: Arguments provided in descripion
+ * @return 0 if OK, -ve on error
+ */
+ int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
+ struct fdtdec_phandle_args *args);
};
/**
*/
unsigned gpio_get_values_as_int(const int *gpio_list);
+/**
+ * gpio_request_by_name() - Locate and request a GPIO by name
+ *
+ * This operates by looking up the given list name in the device (device
+ * tree property) and requesting the GPIO for use. The property must exist
+ * in @dev's node.
+ *
+ * Use @flags to specify whether the GPIO should be an input or output. In
+ * principle this can also come from the device tree binding but most
+ * bindings don't provide this information. Specifically, when the GPIO uclass
+ * calls the xlate() method, it can return default flags, which are then
+ * ORed with this @flags.
+ *
+ * If we find that requesting the GPIO is not always needed we could add a
+ * new function or a new GPIOD_NO_REQUEST flag.
+ *
+ * At present driver model has no reference counting so if one device
+ * requests a GPIO which subsequently is unbound, the @desc->dev pointer
+ * will be invalid. However this will only happen if the GPIO device is
+ * unbound, not if it is removed, so this seems like a reasonable limitation
+ * for now. There is no real use case for unbinding drivers in normal
+ * operation.
+ *
+ * The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
+ * generate terms and each specific device may add additional details in
+ * a binding file in the same directory.
+ *
+ * @dev: Device requesting the GPIO
+ * @list_name: Name of GPIO list (e.g. "board-id-gpios")
+ * @index: Index number of the GPIO in that list use request (0=first)
+ * @desc: Returns GPIO description information. If there is no such
+ * GPIO, dev->dev will be NULL.
+ * @flags: Indicates the GPIO input/output settings (GPIOD_...)
+ * @return 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
+ * something wrong with the list, or other -ve for another error (e.g.
+ * -EBUSY if a GPIO was already requested)
+ */
+int gpio_request_by_name(struct udevice *dev, const char *list_name,
+ int index, struct gpio_desc *desc, int flags);
+
+/**
+ * gpio_request_list_by_name() - Request a list of GPIOs
+ *
+ * Reads all the GPIOs from a list and requetss them. See
+ * gpio_request_by_name() for additional details. Lists should not be
+ * misused to hold unrelated or optional GPIOs. They should only be used
+ * for things like parallel data lines. A zero phandle terminates the list
+ * the list.
+ *
+ * This function will either succeed, and request all GPIOs in the list, or
+ * fail and request none (it will free already-requested GPIOs in case of
+ * an error part-way through).
+ *
+ * @dev: Device requesting the GPIO
+ * @list_name: Name of GPIO list (e.g. "board-id-gpios")
+ * @desc_list: Returns a list of GPIO description information
+ * @max_count: Maximum number of GPIOs to return (@desc_list must be at least
+ * this big)
+ * @flags: Indicates the GPIO input/output settings (GPIOD_...)
+ * @return number of GPIOs requested, or -ve on error
+ */
+int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
+ struct gpio_desc *desc_list, int max_count,
+ int flags);
+
+/**
+ * gpio_get_list_count() - Returns the number of GPIOs in a list
+ *
+ * Counts the GPIOs in a list. See gpio_request_by_name() for additional
+ * details.
+ *
+ * @dev: Device requesting the GPIO
+ * @list_name: Name of GPIO list (e.g. "board-id-gpios")
+ * @return number of GPIOs (0 for an empty property) or -ENOENT if the list
+ * does not exist
+ */
+int gpio_get_list_count(struct udevice *dev, const char *list_name);
+
+/**
+ * gpio_request_by_name_nodev() - request GPIOs without a device
+ *
+ * This is a version of gpio_request_list_by_name() that does not use a
+ * device. Avoid it unless the caller is not yet using driver model
+ */
+int gpio_request_by_name_nodev(const void *blob, int node,
+ const char *list_name,
+ int index, struct gpio_desc *desc, int flags);
+
+/**
+ * gpio_request_list_by_name_nodev() - request GPIOs without a device
+ *
+ * This is a version of gpio_request_list_by_name() that does not use a
+ * device. Avoid it unless the caller is not yet using driver model
+ */
+int gpio_request_list_by_name_nodev(const void *blob, int node,
+ const char *list_name,
+ struct gpio_desc *desc_list, int max_count,
+ int flags);
+
+/**
+ * dm_gpio_free() - Free a single GPIO
+ *
+ * This frees a single GPIOs previously returned from gpio_request_by_name().
+ *
+ * @dev: Device which requested the GPIO
+ * @desc: GPIO to free
+ * @return 0 if OK, -ve on error
+ */
+int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc);
+
+/**
+ * gpio_free_list() - Free a list of GPIOs
+ *
+ * This frees a list of GPIOs previously returned from
+ * gpio_request_list_by_name().
+ *
+ * @dev: Device which requested the GPIOs
+ * @desc: List of GPIOs to free
+ * @count: Number of GPIOs in the list
+ * @return 0 if OK, -ve on error
+ */
+int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count);
+
+/**
+ * gpio_free_list_nodev() - free GPIOs without a device
+ *
+ * This is a version of gpio_free_list() that does not use a
+ * device. Avoid it unless the caller is not yet using driver model
+ */
+int gpio_free_list_nodev(struct gpio_desc *desc, int count);
+
+/**
+ * dm_gpio_get_value() - Get the value of a GPIO
+ *
+ * This is the driver model version of the existing gpio_get_value() function
+ * and should be used instead of that.
+ *
+ * For now, these functions have a dm_ prefix since they conflict with
+ * existing names.
+ *
+ * @desc: GPIO description containing device, offset and flags,
+ * previously returned by gpio_request_by_name()
+ * @return GPIO value (0 for inactive, 1 for active) or -ve on error
+ */
+int dm_gpio_get_value(struct gpio_desc *desc);
+
+int dm_gpio_set_value(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.
+ *
+ * @desc: GPIO description containing device, offset and flags,
+ * previously returned by gpio_request_by_name()
+ * @return 0 if OK, -ve on error
+ */
+int dm_gpio_set_dir(struct gpio_desc *desc);
+
+/**
+ * dm_gpio_set_dir_flags() - Set direction using specific 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.
+ * Note that desc->flags is updated by this function.
+ *
+ * @desc: GPIO description containing device, offset and flags,
+ * previously returned by gpio_request_by_name()
+ * @flags: New flags to use
+ * @return 0 if OK, -ve on error, in which case desc->flags is not updated
+ */
+int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
+
+/**
+ * gpio_get_number() - Get the global GPIO number of a GPIO
+ *
+ * This should only be used for debugging or interest. It returns the nummber
+ * that should be used for gpio_get_value() etc. to access this GPIO.
+ *
+ * @desc: GPIO description containing device, offset and flags,
+ * previously returned by gpio_request_by_name()
+ * @return GPIO number, or -ve if not found
+ */
+int gpio_get_number(struct gpio_desc *desc);
+
#endif /* _ASM_GENERIC_GPIO_H_ */
projects / karo-tx-uboot.git / blobdiff