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1a78958dc2
This switches the way that pins are reserved for multiplexing: We used to do this when the map was parsed, at the creation of the settings inside the pinctrl handle, in pinmux_map_to_setting(). However this does not work for us, because we want to use the same set of pins with different devices at different times: the current code assumes that the pin groups in a pinmux state will only be used with one single device, albeit different groups can be active at different times. For example if a single I2C driver block is used to drive two different busses located on two pin groups A and B, then the pins for all possible states of a function are reserved when fetching the pinctrl handle: the I2C bus can choose either set A or set B by a mux state at runtime, but all pins in both group A and B (the superset) are effectively reserved for that I2C function and mapped to the device. Another device can never get in and use the pins in group A, even if the device/function is using group B at the moment. Instead: let use reserve the pins when the state is activated and drop them when the state is disabled, i.e. when we move to another state. This way different devices/functions can use the same pins at different times. We know that this is an odd way of doing things, but we really need to switch e.g. an SD-card slot to become a tracing output sink at runtime: we plug in a special "tracing card" then mux the pins that used to be an SD slot around to the tracing unit and push out tracing data there instead of SD-card traffic. As a side effect pinmux_free_setting() is unused but the stubs are kept for future additions of code. Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Loic Pallardy <loic.pallardy@st.com> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Jean Nicolas Graux <jean-nicolas.graux@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
169 lines
5.3 KiB
C
169 lines
5.3 KiB
C
/*
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* Core private header for the pin control subsystem
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*
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* Copyright (C) 2011 ST-Ericsson SA
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* Written on behalf of Linaro for ST-Ericsson
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*
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* Author: Linus Walleij <linus.walleij@linaro.org>
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*
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* License terms: GNU General Public License (GPL) version 2
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*/
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#include <linux/mutex.h>
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#include <linux/radix-tree.h>
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#include <linux/pinctrl/pinconf.h>
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#include <linux/pinctrl/machine.h>
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struct pinctrl_gpio_range;
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/**
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* struct pinctrl_dev - pin control class device
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* @node: node to include this pin controller in the global pin controller list
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* @desc: the pin controller descriptor supplied when initializing this pin
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* controller
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* @pin_desc_tree: each pin descriptor for this pin controller is stored in
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* this radix tree
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* @gpio_ranges: a list of GPIO ranges that is handled by this pin controller,
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* ranges are added to this list at runtime
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* @dev: the device entry for this pin controller
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* @owner: module providing the pin controller, used for refcounting
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* @driver_data: driver data for drivers registering to the pin controller
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* subsystem
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* @p: result of pinctrl_get() for this device
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* @device_root: debugfs root for this device
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*/
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struct pinctrl_dev {
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struct list_head node;
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struct pinctrl_desc *desc;
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struct radix_tree_root pin_desc_tree;
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struct list_head gpio_ranges;
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struct device *dev;
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struct module *owner;
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void *driver_data;
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struct pinctrl *p;
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#ifdef CONFIG_DEBUG_FS
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struct dentry *device_root;
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#endif
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};
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/**
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* struct pinctrl - per-device pin control state holder
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* @node: global list node
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* @dev: the device using this pin control handle
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* @states: a list of states for this device
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* @state: the current state
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* @dt_maps: the mapping table chunks dynamically parsed from device tree for
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* this device, if any
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*/
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struct pinctrl {
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struct list_head node;
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struct device *dev;
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struct list_head states;
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struct pinctrl_state *state;
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struct list_head dt_maps;
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};
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/**
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* struct pinctrl_state - a pinctrl state for a device
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* @node: list not for struct pinctrl's @states field
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* @name: the name of this state
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* @settings: a list of settings for this state
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*/
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struct pinctrl_state {
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struct list_head node;
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const char *name;
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struct list_head settings;
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};
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/**
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* struct pinctrl_setting_mux - setting data for MAP_TYPE_MUX_GROUP
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* @group: the group selector to program
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* @func: the function selector to program
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*/
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struct pinctrl_setting_mux {
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unsigned group;
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unsigned func;
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};
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/**
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* struct pinctrl_setting_configs - setting data for MAP_TYPE_CONFIGS_*
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* @group_or_pin: the group selector or pin ID to program
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* @configs: a pointer to an array of config parameters/values to program into
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* hardware. Each individual pin controller defines the format and meaning
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* of config parameters.
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* @num_configs: the number of entries in array @configs
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*/
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struct pinctrl_setting_configs {
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unsigned group_or_pin;
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unsigned long *configs;
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unsigned num_configs;
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};
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/**
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* struct pinctrl_setting - an individual mux or config setting
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* @node: list node for struct pinctrl_settings's @settings field
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* @type: the type of setting
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* @pctldev: pin control device handling to be programmed. Not used for
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* PIN_MAP_TYPE_DUMMY_STATE.
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* @dev_name: the name of the device using this state
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* @data: Data specific to the setting type
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*/
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struct pinctrl_setting {
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struct list_head node;
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enum pinctrl_map_type type;
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struct pinctrl_dev *pctldev;
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const char *dev_name;
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union {
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struct pinctrl_setting_mux mux;
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struct pinctrl_setting_configs configs;
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} data;
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};
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/**
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* struct pin_desc - pin descriptor for each physical pin in the arch
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* @pctldev: corresponding pin control device
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* @name: a name for the pin, e.g. the name of the pin/pad/finger on a
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* datasheet or such
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* @dynamic_name: if the name of this pin was dynamically allocated
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* @mux_usecount: If zero, the pin is not claimed, and @owner should be NULL.
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* If non-zero, this pin is claimed by @owner. This field is an integer
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* rather than a boolean, since pinctrl_get() might process multiple
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* mapping table entries that refer to, and hence claim, the same group
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* or pin, and each of these will increment the @usecount.
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* @mux_owner: The name of device that called pinctrl_get().
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* @mux_setting: The most recent selected mux setting for this pin, if any.
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* @gpio_owner: If pinctrl_request_gpio() was called for this pin, this is
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* the name of the GPIO that "owns" this pin.
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*/
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struct pin_desc {
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struct pinctrl_dev *pctldev;
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const char *name;
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bool dynamic_name;
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/* These fields only added when supporting pinmux drivers */
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#ifdef CONFIG_PINMUX
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unsigned mux_usecount;
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const char *mux_owner;
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const struct pinctrl_setting_mux *mux_setting;
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const char *gpio_owner;
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#endif
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};
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struct pinctrl_dev *get_pinctrl_dev_from_devname(const char *dev_name);
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int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name);
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const char *pin_get_name(struct pinctrl_dev *pctldev, const unsigned pin);
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int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
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const char *pin_group);
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static inline struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev,
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unsigned int pin)
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{
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return radix_tree_lookup(&pctldev->pin_desc_tree, pin);
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}
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int pinctrl_register_map(struct pinctrl_map const *maps, unsigned num_maps,
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bool dup, bool locked);
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void pinctrl_unregister_map(struct pinctrl_map const *map);
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extern struct mutex pinctrl_mutex;
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extern struct list_head pinctrldev_list;
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