linux-stable/include/linux/pinctrl/machine.h
Hans de Goede c72bed23b9 pinctrl: Allow modules to use pinctrl_[un]register_mappings
Currently only the drivers/pinctrl/devicetree.c code allows registering
pinctrl-mappings which may later be unregistered, all other mappings
are assumed to be permanent.

Non-dt platforms may also want to register pinctrl mappings from code which
is build as a module, which requires being able to unregister the mapping
when the module is unloaded to avoid dangling pointers.

To allow unregistering the mappings the devicetree code uses 2 internal
functions: pinctrl_register_map and pinctrl_unregister_map.

pinctrl_register_map allows the devicetree code to tell the core to
not memdup the mappings as it retains ownership of them and
pinctrl_unregister_map does the unregistering, note this only works
when the mappings where not memdupped.

The only code relying on the memdup/shallow-copy done by
pinctrl_register_mappings is arch/arm/mach-u300/core.c this commit
replaces the __initdata with const, so that the shallow-copy is no
longer necessary.

After that we can get rid of the internal pinctrl_unregister_map function
and just use pinctrl_register_mappings directly everywhere.

This commit also renames pinctrl_unregister_map to
pinctrl_unregister_mappings so that its naming matches its
pinctrl_register_mappings counter-part and exports it.

Together these 2 changes will allow non-dt platform code to
register pinctrl-mappings from modules without breaking things on
module unload (as they can now unregister the mapping on unload).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20191216205122.1850923-2-hdegoede@redhat.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-12-30 14:27:17 +01:00

174 lines
5.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Machine interface for the pinctrl subsystem.
*
* Copyright (C) 2011 ST-Ericsson SA
* Written on behalf of Linaro for ST-Ericsson
* Based on bits of regulator core, gpio core and clk core
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*/
#ifndef __LINUX_PINCTRL_MACHINE_H
#define __LINUX_PINCTRL_MACHINE_H
#include <linux/bug.h>
#include <linux/pinctrl/pinctrl-state.h>
enum pinctrl_map_type {
PIN_MAP_TYPE_INVALID,
PIN_MAP_TYPE_DUMMY_STATE,
PIN_MAP_TYPE_MUX_GROUP,
PIN_MAP_TYPE_CONFIGS_PIN,
PIN_MAP_TYPE_CONFIGS_GROUP,
};
/**
* struct pinctrl_map_mux - mapping table content for MAP_TYPE_MUX_GROUP
* @group: the name of the group whose mux function is to be configured. This
* field may be left NULL, and the first applicable group for the function
* will be used.
* @function: the mux function to select for the group
*/
struct pinctrl_map_mux {
const char *group;
const char *function;
};
/**
* struct pinctrl_map_configs - mapping table content for MAP_TYPE_CONFIGS_*
* @group_or_pin: the name of the pin or group whose configuration parameters
* are to be configured.
* @configs: a pointer to an array of config parameters/values to program into
* hardware. Each individual pin controller defines the format and meaning
* of config parameters.
* @num_configs: the number of entries in array @configs
*/
struct pinctrl_map_configs {
const char *group_or_pin;
unsigned long *configs;
unsigned num_configs;
};
/**
* struct pinctrl_map - boards/machines shall provide this map for devices
* @dev_name: the name of the device using this specific mapping, the name
* must be the same as in your struct device*. If this name is set to the
* same name as the pin controllers own dev_name(), the map entry will be
* hogged by the driver itself upon registration
* @name: the name of this specific map entry for the particular machine.
* This is the parameter passed to pinmux_lookup_state()
* @type: the type of mapping table entry
* @ctrl_dev_name: the name of the device controlling this specific mapping,
* the name must be the same as in your struct device*. This field is not
* used for PIN_MAP_TYPE_DUMMY_STATE
* @data: Data specific to the mapping type
*/
struct pinctrl_map {
const char *dev_name;
const char *name;
enum pinctrl_map_type type;
const char *ctrl_dev_name;
union {
struct pinctrl_map_mux mux;
struct pinctrl_map_configs configs;
} data;
};
/* Convenience macros to create mapping table entries */
#define PIN_MAP_DUMMY_STATE(dev, state) \
{ \
.dev_name = dev, \
.name = state, \
.type = PIN_MAP_TYPE_DUMMY_STATE, \
}
#define PIN_MAP_MUX_GROUP(dev, state, pinctrl, grp, func) \
{ \
.dev_name = dev, \
.name = state, \
.type = PIN_MAP_TYPE_MUX_GROUP, \
.ctrl_dev_name = pinctrl, \
.data.mux = { \
.group = grp, \
.function = func, \
}, \
}
#define PIN_MAP_MUX_GROUP_DEFAULT(dev, pinctrl, grp, func) \
PIN_MAP_MUX_GROUP(dev, PINCTRL_STATE_DEFAULT, pinctrl, grp, func)
#define PIN_MAP_MUX_GROUP_HOG(dev, state, grp, func) \
PIN_MAP_MUX_GROUP(dev, state, dev, grp, func)
#define PIN_MAP_MUX_GROUP_HOG_DEFAULT(dev, grp, func) \
PIN_MAP_MUX_GROUP(dev, PINCTRL_STATE_DEFAULT, dev, grp, func)
#define PIN_MAP_CONFIGS_PIN(dev, state, pinctrl, pin, cfgs) \
{ \
.dev_name = dev, \
.name = state, \
.type = PIN_MAP_TYPE_CONFIGS_PIN, \
.ctrl_dev_name = pinctrl, \
.data.configs = { \
.group_or_pin = pin, \
.configs = cfgs, \
.num_configs = ARRAY_SIZE(cfgs), \
}, \
}
#define PIN_MAP_CONFIGS_PIN_DEFAULT(dev, pinctrl, pin, cfgs) \
PIN_MAP_CONFIGS_PIN(dev, PINCTRL_STATE_DEFAULT, pinctrl, pin, cfgs)
#define PIN_MAP_CONFIGS_PIN_HOG(dev, state, pin, cfgs) \
PIN_MAP_CONFIGS_PIN(dev, state, dev, pin, cfgs)
#define PIN_MAP_CONFIGS_PIN_HOG_DEFAULT(dev, pin, cfgs) \
PIN_MAP_CONFIGS_PIN(dev, PINCTRL_STATE_DEFAULT, dev, pin, cfgs)
#define PIN_MAP_CONFIGS_GROUP(dev, state, pinctrl, grp, cfgs) \
{ \
.dev_name = dev, \
.name = state, \
.type = PIN_MAP_TYPE_CONFIGS_GROUP, \
.ctrl_dev_name = pinctrl, \
.data.configs = { \
.group_or_pin = grp, \
.configs = cfgs, \
.num_configs = ARRAY_SIZE(cfgs), \
}, \
}
#define PIN_MAP_CONFIGS_GROUP_DEFAULT(dev, pinctrl, grp, cfgs) \
PIN_MAP_CONFIGS_GROUP(dev, PINCTRL_STATE_DEFAULT, pinctrl, grp, cfgs)
#define PIN_MAP_CONFIGS_GROUP_HOG(dev, state, grp, cfgs) \
PIN_MAP_CONFIGS_GROUP(dev, state, dev, grp, cfgs)
#define PIN_MAP_CONFIGS_GROUP_HOG_DEFAULT(dev, grp, cfgs) \
PIN_MAP_CONFIGS_GROUP(dev, PINCTRL_STATE_DEFAULT, dev, grp, cfgs)
#ifdef CONFIG_PINCTRL
extern int pinctrl_register_mappings(const struct pinctrl_map *map,
unsigned num_maps);
extern void pinctrl_unregister_mappings(const struct pinctrl_map *map);
extern void pinctrl_provide_dummies(void);
#else
static inline int pinctrl_register_mappings(const struct pinctrl_map *map,
unsigned num_maps)
{
return 0;
}
static inline void pinctrl_unregister_mappings(const struct pinctrl_map *map)
{
}
static inline void pinctrl_provide_dummies(void)
{
}
#endif /* !CONFIG_PINCTRL */
#endif