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9c08fbfc95
The pinmux property allows for smaller and more compact device trees, especially when there are many pins which need to be assigned individually. Instead of specifying an array of strings to be parsed as pins and a function property, the pinmux property contains an array of integers representing pinmux groups. A pinmux group consists of the pin identifier and mux settings represented as a single integer or an array of integers. Each individual pin controller driver specifies the exact format of a pinmux group. As specified in the Linux documentation, a pinmux group may be multiple integers long. However, no existing drivers use multi-integer pinmux groups, so I have chosen to omit this feature. This makes the implementation easier, since there is no need to allocate a buffer to do endian conversions. Support for the pinmux property is done differently than in Linux. As far as I can tell, inversion of control is used when implementing support for the pins and groups properties to avoid allocating. This results in some duplication of effort; every property in a config node is parsed once for each pin in that node. This is not such an overhead with pins and groups properties, since having multiple pins in one config node does not occur especially often. However, the semantics of the pinmux property make such a configuration much more appealing. A future patch could parse all config properties at once and store them in an array. This would make it easier to create drivers which do not function solely as callbacks from pinctrl-generic. This commit increases the size of the sandbox build by approximately 48 bytes. However, it also decreases the size of the K210 device tree by 2 KiB from the previous version of this series. The documentation has been updated from the last Linux commit before it was split off into yaml files. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org>
450 lines
18 KiB
C
450 lines
18 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
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*/
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#ifndef __PINCTRL_H
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#define __PINCTRL_H
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#define PINNAME_SIZE 10
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#define PINMUX_SIZE 40
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/**
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* struct pinconf_param - pin config parameters
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*
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* @property: property name in DT nodes
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* @param: ID for this config parameter
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* @default_value: default value for this config parameter used in case
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* no value is specified in DT nodes
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*/
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struct pinconf_param {
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const char * const property;
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unsigned int param;
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u32 default_value;
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};
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/**
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* struct pinctrl_ops - pin control operations, to be implemented by
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* pin controller drivers.
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*
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* The @set_state is the only mandatory operation. You can implement your
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* pinctrl driver with its own @set_state. In this case, the other callbacks
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* are not required. Otherwise, generic pinctrl framework is also available;
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* use pinctrl_generic_set_state for @set_state, and implement other operations
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* depending on your necessity.
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*
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* @get_pins_count: return number of selectable named pins available
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* in this driver. (necessary to parse "pins" property in DTS)
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* @get_pin_name: return the pin name of the pin selector,
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* called by the core to figure out which pin it shall do
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* operations to. (necessary to parse "pins" property in DTS)
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* @get_groups_count: return number of selectable named groups available
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* in this driver. (necessary to parse "groups" property in DTS)
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* @get_group_name: return the group name of the group selector,
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* called by the core to figure out which pin group it shall do
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* operations to. (necessary to parse "groups" property in DTS)
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* @get_functions_count: return number of selectable named functions available
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* in this driver. (necessary for pin-muxing)
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* @get_function_name: return the function name of the muxing selector,
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* called by the core to figure out which mux setting it shall map a
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* certain device to. (necessary for pin-muxing)
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* @pinmux_set: enable a certain muxing function with a certain pin.
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* The @func_selector selects a certain function whereas @pin_selector
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* selects a certain pin to be used. On simple controllers one of them
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* may be ignored. (necessary for pin-muxing against a single pin)
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* @pinmux_group_set: enable a certain muxing function with a certain pin
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* group. The @func_selector selects a certain function whereas
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* @group_selector selects a certain set of pins to be used. On simple
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* controllers one of them may be ignored.
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* (necessary for pin-muxing against a pin group)
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* @pinmux_property_set: enable a pinmux group. @pinmux_group should specify the
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* pin identifier and mux settings. The exact format of a pinmux group is
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* left up to the driver. The pin selector for the mux-ed pin should be
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* returned on success. (necessary to parse the "pinmux" property in DTS)
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* @pinconf_num_params: number of driver-specific parameters to be parsed
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* from device trees (necessary for pin-configuration)
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* @pinconf_params: list of driver_specific parameters to be parsed from
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* device trees (necessary for pin-configuration)
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* @pinconf_set: configure an individual pin with a given parameter.
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* (necessary for pin-configuration against a single pin)
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* @pinconf_group_set: configure all pins in a group with a given parameter.
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* (necessary for pin-configuration against a pin group)
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* @set_state: do pinctrl operations specified by @config, a pseudo device
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* pointing a config node. (necessary for pinctrl_full)
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* @set_state_simple: do needed pinctrl operations for a peripherl @periph.
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* (necessary for pinctrl_simple)
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* @get_pin_muxing: display the muxing of a given pin.
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* @gpio_request_enable: requests and enables GPIO on a certain pin.
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* Implement this only if you can mux every pin individually as GPIO. The
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* affected GPIO range is passed along with an offset(pin number) into that
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* specific GPIO range - function selectors and pin groups are orthogonal
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* to this, the core will however make sure the pins do not collide.
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* @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of
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* @gpio_request_enable
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*/
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struct pinctrl_ops {
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int (*get_pins_count)(struct udevice *dev);
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const char *(*get_pin_name)(struct udevice *dev, unsigned selector);
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int (*get_groups_count)(struct udevice *dev);
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const char *(*get_group_name)(struct udevice *dev, unsigned selector);
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int (*get_functions_count)(struct udevice *dev);
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const char *(*get_function_name)(struct udevice *dev,
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unsigned selector);
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int (*pinmux_set)(struct udevice *dev, unsigned pin_selector,
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unsigned func_selector);
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int (*pinmux_group_set)(struct udevice *dev, unsigned group_selector,
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unsigned func_selector);
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int (*pinmux_property_set)(struct udevice *dev, u32 pinmux_group);
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unsigned int pinconf_num_params;
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const struct pinconf_param *pinconf_params;
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int (*pinconf_set)(struct udevice *dev, unsigned pin_selector,
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unsigned param, unsigned argument);
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int (*pinconf_group_set)(struct udevice *dev, unsigned group_selector,
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unsigned param, unsigned argument);
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int (*set_state)(struct udevice *dev, struct udevice *config);
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/* for pinctrl-simple */
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int (*set_state_simple)(struct udevice *dev, struct udevice *periph);
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/**
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* request() - Request a particular pinctrl function
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*
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* This activates the selected function.
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*
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* @dev: Device to adjust (UCLASS_PINCTRL)
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* @func: Function number (driver-specific)
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* @return 0 if OK, -ve on error
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*/
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int (*request)(struct udevice *dev, int func, int flags);
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/**
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* get_periph_id() - get the peripheral ID for a device
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*
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* This generally looks at the peripheral's device tree node to work
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* out the peripheral ID. The return value is normally interpreted as
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* enum periph_id. so long as this is defined by the platform (which it
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* should be).
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*
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* @dev: Pinctrl device to use for decoding
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* @periph: Device to check
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* @return peripheral ID of @periph, or -ENOENT on error
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*/
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int (*get_periph_id)(struct udevice *dev, struct udevice *periph);
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/**
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* get_gpio_mux() - get the mux value for a particular GPIO
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*
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* This allows the raw mux value for a GPIO to be obtained. It is
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* useful for displaying the function being used by that GPIO, such
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* as with the 'gpio' command. This function is internal to the GPIO
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* subsystem and should not be used by generic code. Typically it is
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* used by a GPIO driver with knowledge of the SoC pinctrl setup.
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*
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* @dev: Pinctrl device to use
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* @banknum: GPIO bank number
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* @index: GPIO index within the bank
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* @return mux value (SoC-specific, e.g. 0 for input, 1 for output)
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*/
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int (*get_gpio_mux)(struct udevice *dev, int banknum, int index);
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/**
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* get_pin_muxing() - show pin muxing
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*
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* This allows to display the muxing of a given pin. It's useful for
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* debug purpose to know if a pin is configured as GPIO or as an
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* alternate function and which one.
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* Typically it is used by a PINCTRL driver with knowledge of the SoC
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* pinctrl setup.
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*
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* @dev: Pinctrl device to use
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* @selector: Pin selector
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* @buf Pin's muxing description
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* @size Pin's muxing description length
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* return 0 if OK, -ve on error
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*/
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int (*get_pin_muxing)(struct udevice *dev, unsigned int selector,
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char *buf, int size);
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/**
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* gpio_request_enable: requests and enables GPIO on a certain pin.
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*
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* @dev: Pinctrl device to use
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* @selector: Pin selector
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* return 0 if OK, -ve on error
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*/
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int (*gpio_request_enable)(struct udevice *dev, unsigned int selector);
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/**
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* gpio_disable_free: free up GPIO muxing on a certain pin.
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*
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* @dev: Pinctrl device to use
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* @selector: Pin selector
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* return 0 if OK, -ve on error
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*/
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int (*gpio_disable_free)(struct udevice *dev, unsigned int selector);
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};
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#define pinctrl_get_ops(dev) ((struct pinctrl_ops *)(dev)->driver->ops)
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/**
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* Generic pin configuration paramters
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*
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* enum pin_config_param - possible pin configuration parameters
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* @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
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* weakly drives the last value on a tristate bus, also known as a "bus
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* holder", "bus keeper" or "repeater". This allows another device on the
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* bus to change the value by driving the bus high or low and switching to
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* tristate. The argument is ignored.
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* @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
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* transition from say pull-up to pull-down implies that you disable
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* pull-up in the process, this setting disables all biasing.
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* @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
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* mode, also know as "third-state" (tristate) or "high-Z" or "floating".
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* On output pins this effectively disconnects the pin, which is useful
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* if for example some other pin is going to drive the signal connected
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* to it for a while. Pins used for input are usually always high
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* impedance.
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* @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
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* impedance to GROUND). If the argument is != 0 pull-down is enabled,
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* if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
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* @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
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* on embedded knowledge of the controller hardware, like current mux
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* function. The pull direction and possibly strength too will normally
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* be decided completely inside the hardware block and not be readable
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* from the kernel side.
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* If the argument is != 0 pull up/down is enabled, if it is 0, the
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* configuration is ignored. The proper way to disable it is to use
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* @PIN_CONFIG_BIAS_DISABLE.
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* @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
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* impedance to VDD). If the argument is != 0 pull-up is enabled,
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* if it is 0, pull-up is total, i.e. the pin is connected to VDD.
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* @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
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* collector) which means it is usually wired with other output ports
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* which are then pulled up with an external resistor. Setting this
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* config will enable open drain mode, the argument is ignored.
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* @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
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* (open emitter). Setting this config will enable open source mode, the
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* argument is ignored.
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* @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
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* low, this is the most typical case and is typically achieved with two
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* active transistors on the output. Setting this config will enable
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* push-pull mode, the argument is ignored.
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* @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
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* passed as argument. The argument is in mA.
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* @PIN_CONFIG_DRIVE_STRENGTH_UA: the pin will sink or source at most the current
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* passed as argument. The argument is in uA.
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* @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
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* which means it will wait for signals to settle when reading inputs. The
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* argument gives the debounce time in usecs. Setting the
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* argument to zero turns debouncing off.
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* @PIN_CONFIG_INPUT_ENABLE: enable the pin's input. Note that this does not
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* affect the pin's ability to drive output. 1 enables input, 0 disables
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* input.
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* @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
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* schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
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* the threshold value is given on a custom format as argument when
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* setting pins to this mode.
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* @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
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* If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
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* schmitt-trigger mode is disabled.
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* @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
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* operation, if several modes of operation are supported these can be
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* passed in the argument on a custom form, else just use argument 1
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* to indicate low power mode, argument 0 turns low power mode off.
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* @PIN_CONFIG_OUTPUT_ENABLE: this will enable the pin's output mode
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* without driving a value there. For most platforms this reduces to
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* enable the output buffers and then let the pin controller current
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* configuration (eg. the currently selected mux function) drive values on
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* the line. Use argument 1 to enable output mode, argument 0 to disable
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* it.
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* @PIN_CONFIG_OUTPUT: this will configure the pin as an output and drive a
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* value on the line. Use argument 1 to indicate high level, argument 0 to
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* indicate low level. (Please see Documentation/driver-api/pinctl.rst,
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* section "GPIO mode pitfalls" for a discussion around this parameter.)
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* @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
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* supplies, the argument to this parameter (on a custom format) tells
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* the driver which alternative power source to use.
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* @PIN_CONFIG_SLEEP_HARDWARE_STATE: indicate this is sleep related state.
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* @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
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* this parameter (on a custom format) tells the driver which alternative
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* slew rate to use.
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* @PIN_CONFIG_SKEW_DELAY: if the pin has programmable skew rate (on inputs)
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* or latch delay (on outputs) this parameter (in a custom format)
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* specifies the clock skew or latch delay. It typically controls how
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* many double inverters are put in front of the line.
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* @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
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* you need to pass in custom configurations to the pin controller, use
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* PIN_CONFIG_END+1 as the base offset.
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* @PIN_CONFIG_MAX: this is the maximum configuration value that can be
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* presented using the packed format.
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*/
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enum pin_config_param {
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PIN_CONFIG_BIAS_BUS_HOLD,
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PIN_CONFIG_BIAS_DISABLE,
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PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
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PIN_CONFIG_BIAS_PULL_DOWN,
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PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
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PIN_CONFIG_BIAS_PULL_UP,
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PIN_CONFIG_DRIVE_OPEN_DRAIN,
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PIN_CONFIG_DRIVE_OPEN_SOURCE,
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PIN_CONFIG_DRIVE_PUSH_PULL,
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PIN_CONFIG_DRIVE_STRENGTH,
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PIN_CONFIG_DRIVE_STRENGTH_UA,
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PIN_CONFIG_INPUT_DEBOUNCE,
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PIN_CONFIG_INPUT_ENABLE,
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PIN_CONFIG_INPUT_SCHMITT,
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PIN_CONFIG_INPUT_SCHMITT_ENABLE,
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PIN_CONFIG_LOW_POWER_MODE,
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PIN_CONFIG_OUTPUT_ENABLE,
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PIN_CONFIG_OUTPUT,
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PIN_CONFIG_POWER_SOURCE,
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PIN_CONFIG_SLEEP_HARDWARE_STATE,
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PIN_CONFIG_SLEW_RATE,
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PIN_CONFIG_SKEW_DELAY,
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PIN_CONFIG_END = 0x7F,
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PIN_CONFIG_MAX = 0xFF,
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};
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#if CONFIG_IS_ENABLED(PINCTRL_GENERIC)
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/**
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* pinctrl_generic_set_state() - generic set_state operation
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* Parse the DT node of @config and its children and handle generic properties
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* such as "pins", "groups", "functions", and pin configuration parameters.
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*
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* @pctldev: pinctrl device
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* @config: config device (pseudo device), pointing a config node in DTS
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* @return: 0 on success, or negative error code on failure
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*/
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int pinctrl_generic_set_state(struct udevice *pctldev, struct udevice *config);
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#else
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static inline int pinctrl_generic_set_state(struct udevice *pctldev,
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struct udevice *config)
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{
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return -EINVAL;
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}
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#endif
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#if CONFIG_IS_ENABLED(PINCTRL)
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/**
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* pinctrl_select_state() - set a device to a given state
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*
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* @dev: peripheral device
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* @statename: state name, like "default"
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* @return: 0 on success, or negative error code on failure
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*/
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int pinctrl_select_state(struct udevice *dev, const char *statename);
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#else
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static inline int pinctrl_select_state(struct udevice *dev,
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const char *statename)
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{
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return -EINVAL;
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}
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#endif
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/**
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* pinctrl_request() - Request a particular pinctrl function
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*
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* @dev: Device to check (UCLASS_PINCTRL)
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* @func: Function number (driver-specific)
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* @flags: Flags (driver-specific)
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* @return 0 if OK, -ve on error
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*/
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int pinctrl_request(struct udevice *dev, int func, int flags);
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/**
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* pinctrl_request_noflags() - Request a particular pinctrl function
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*
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* This is similar to pinctrl_request() but uses 0 for @flags.
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*
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* @dev: Device to check (UCLASS_PINCTRL)
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* @func: Function number (driver-specific)
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* @return 0 if OK, -ve on error
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*/
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int pinctrl_request_noflags(struct udevice *dev, int func);
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/**
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* pinctrl_get_periph_id() - get the peripheral ID for a device
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*
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* This generally looks at the peripheral's device tree node to work out the
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* peripheral ID. The return value is normally interpreted as enum periph_id.
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* so long as this is defined by the platform (which it should be).
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*
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* @dev: Pinctrl device to use for decoding
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* @periph: Device to check
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* @return peripheral ID of @periph, or -ENOENT on error
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*/
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int pinctrl_get_periph_id(struct udevice *dev, struct udevice *periph);
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/**
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* pinctrl_get_gpio_mux() - get the mux value for a particular GPIO
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*
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* This allows the raw mux value for a GPIO to be obtained. It is
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* useful for displaying the function being used by that GPIO, such
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* as with the 'gpio' command. This function is internal to the GPIO
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* subsystem and should not be used by generic code. Typically it is
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* used by a GPIO driver with knowledge of the SoC pinctrl setup.
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*
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* @dev: Pinctrl device to use
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* @banknum: GPIO bank number
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* @index: GPIO index within the bank
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* @return mux value (SoC-specific, e.g. 0 for input, 1 for output)
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*/
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int pinctrl_get_gpio_mux(struct udevice *dev, int banknum, int index);
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/**
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* pinctrl_get_pin_muxing() - Returns the muxing description
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*
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* This allows to display the muxing description of the given pin for
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* debug purpose
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*
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* @dev: Pinctrl device to use
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* @selector Pin index within pin-controller
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* @buf Pin's muxing description
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* @size Pin's muxing description length
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* @return 0 if OK, -ve on error
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*/
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int pinctrl_get_pin_muxing(struct udevice *dev, int selector, char *buf,
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int size);
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|
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/**
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* pinctrl_get_pins_count() - display pin-controller pins number
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|
*
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|
* This allows to know the number of pins owned by a given pin-controller
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|
*
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|
* @dev: Pinctrl device to use
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|
* @return pins number if OK, -ve on error
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|
*/
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|
int pinctrl_get_pins_count(struct udevice *dev);
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|
|
|
/**
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|
* pinctrl_get_pin_name() - Returns the pin's name
|
|
*
|
|
* This allows to display the pin's name for debug purpose
|
|
*
|
|
* @dev: Pinctrl device to use
|
|
* @selector Pin index within pin-controller
|
|
* @buf Pin's name
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|
* @return 0 if OK, -ve on error
|
|
*/
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|
int pinctrl_get_pin_name(struct udevice *dev, int selector, char *buf,
|
|
int size);
|
|
|
|
/**
|
|
* pinctrl_gpio_request() - request a single pin to be used as GPIO
|
|
*
|
|
* @dev: GPIO peripheral device
|
|
* @offset: the GPIO pin offset from the GPIO controller
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|
* @return: 0 on success, or negative error code on failure
|
|
*/
|
|
int pinctrl_gpio_request(struct udevice *dev, unsigned offset);
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|
|
|
/**
|
|
* pinctrl_gpio_free() - free a single pin used as GPIO
|
|
*
|
|
* @dev: GPIO peripheral device
|
|
* @offset: the GPIO pin offset from the GPIO controller
|
|
* @return: 0 on success, or negative error code on failure
|
|
*/
|
|
int pinctrl_gpio_free(struct udevice *dev, unsigned offset);
|
|
|
|
#endif /* __PINCTRL_H */
|