kernel_optimize_test/drivers/pinctrl/core.h
Stephen Warren 0e3db173e2 pinctrl: add usecount to pins for muxing
Multiple mapping table entries could reference the same pin, and hence
"own" it. This would be unusual now that pinctrl_get() represents a single
state for a client device, but in the future when it represents all known
states for a device, this is quite likely. Implement reference counting
for pin ownership to handle this.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-05 11:21:46 +01:00

117 lines
3.7 KiB
C

/*
* Core private header for the pin control subsystem
*
* Copyright (C) 2011 ST-Ericsson SA
* Written on behalf of Linaro for ST-Ericsson
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* License terms: GNU General Public License (GPL) version 2
*/
#include <linux/mutex.h>
#include <linux/radix-tree.h>
#include <linux/pinctrl/pinconf.h>
struct pinctrl_gpio_range;
/**
* struct pinctrl_dev - pin control class device
* @node: node to include this pin controller in the global pin controller list
* @desc: the pin controller descriptor supplied when initializing this pin
* controller
* @pin_desc_tree: each pin descriptor for this pin controller is stored in
* this radix tree
* @gpio_ranges: a list of GPIO ranges that is handled by this pin controller,
* ranges are added to this list at runtime
* @dev: the device entry for this pin controller
* @owner: module providing the pin controller, used for refcounting
* @driver_data: driver data for drivers registering to the pin controller
* subsystem
* @p: result of pinctrl_get() for this device
* @device_root: debugfs root for this device
*/
struct pinctrl_dev {
struct list_head node;
struct pinctrl_desc *desc;
struct radix_tree_root pin_desc_tree;
struct list_head gpio_ranges;
struct device *dev;
struct module *owner;
void *driver_data;
struct pinctrl *p;
#ifdef CONFIG_DEBUG_FS
struct dentry *device_root;
#endif
};
/**
* struct pinctrl - per-device pin control state holder
* @node: global list node
* @dev: the device using this pin control handle
* @state: the state name passed to pinctrl_get()
* @usecount: the number of active users of this pin controller setting, used
* to keep track of nested use cases
* @settings: a list of settings for this device/state
*/
struct pinctrl {
struct list_head node;
struct device *dev;
const char *state;
unsigned usecount;
struct list_head settings;
};
/**
* struct pinctrl_setting - an individual mux setting
* @node: list node for struct pinctrl's @settings field
* @pctldev: pin control device handling to be programmed
* @group_selector: the group selector to program
* @func_selector: the function selector to program
*/
struct pinctrl_setting {
struct list_head node;
struct pinctrl_dev *pctldev;
unsigned group_selector;
unsigned func_selector;
};
/**
* struct pin_desc - pin descriptor for each physical pin in the arch
* @pctldev: corresponding pin control device
* @name: a name for the pin, e.g. the name of the pin/pad/finger on a
* datasheet or such
* @dynamic_name: if the name of this pin was dynamically allocated
* @usecount: If zero, the pin is not claimed, and @owner should be NULL.
* If non-zero, this pin is claimed by @owner. This field is an integer
* rather than a boolean, since pinctrl_get() might process multiple
* mapping table entries that refer to, and hence claim, the same group
* or pin, and each of these will increment the @usecount.
* @owner: The name of the entity owning the pin. Typically, this is the name
* of the device that called pinctrl_get(). Alternatively, it may be the
* name of the GPIO passed to pinctrl_request_gpio().
*/
struct pin_desc {
struct pinctrl_dev *pctldev;
const char *name;
bool dynamic_name;
/* These fields only added when supporting pinmux drivers */
#ifdef CONFIG_PINMUX
unsigned usecount;
const char *owner;
#endif
};
struct pinctrl_dev *get_pinctrl_dev_from_devname(const char *dev_name);
int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name);
int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
const char *pin_group);
static inline struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev,
unsigned int pin)
{
return radix_tree_lookup(&pctldev->pin_desc_tree, pin);
}
extern struct mutex pinctrl_mutex;