linux-hardened/include/linux/clk-private.h
Sylwester Nawrocki fcb0ee6a3d clk: Implement clk_unregister
clk_unregister() is currently not implemented and it is required when
a clock provider module needs to be unloaded.

Normally the clock supplier module is prevented to be unloaded by
taking reference on the module in clk_get().

For cases when the clock supplier module deinitializes despite the
consumers of its clocks holding a reference on the module, e.g. when
the driver is unbound through "unbind" sysfs attribute, there are
empty clock ops added. These ops are assigned temporarily to struct
clk and used until all consumers release the clock, to avoid invoking
callbacks from the module which just got removed.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
2013-12-04 17:19:52 +01:00

217 lines
6.1 KiB
C

/*
* linux/include/linux/clk-private.h
*
* Copyright (c) 2010-2011 Jeremy Kerr <jeremy.kerr@canonical.com>
* Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __LINUX_CLK_PRIVATE_H
#define __LINUX_CLK_PRIVATE_H
#include <linux/clk-provider.h>
#include <linux/kref.h>
#include <linux/list.h>
/*
* WARNING: Do not include clk-private.h from any file that implements struct
* clk_ops. Doing so is a layering violation!
*
* This header exists only to allow for statically initialized clock data. Any
* static clock data must be defined in a separate file from the logic that
* implements the clock operations for that same data.
*/
#ifdef CONFIG_COMMON_CLK
struct module;
struct clk {
const char *name;
const struct clk_ops *ops;
struct clk_hw *hw;
struct module *owner;
struct clk *parent;
const char **parent_names;
struct clk **parents;
u8 num_parents;
u8 new_parent_index;
unsigned long rate;
unsigned long new_rate;
struct clk *new_parent;
struct clk *new_child;
unsigned long flags;
unsigned int enable_count;
unsigned int prepare_count;
struct hlist_head children;
struct hlist_node child_node;
unsigned int notifier_count;
#ifdef CONFIG_COMMON_CLK_DEBUG
struct dentry *dentry;
#endif
struct kref ref;
};
/*
* DOC: Basic clock implementations common to many platforms
*
* Each basic clock hardware type is comprised of a structure describing the
* clock hardware, implementations of the relevant callbacks in struct clk_ops,
* unique flags for that hardware type, a registration function and an
* alternative macro for static initialization
*/
#define DEFINE_CLK(_name, _ops, _flags, _parent_names, \
_parents) \
static struct clk _name = { \
.name = #_name, \
.ops = &_ops, \
.hw = &_name##_hw.hw, \
.parent_names = _parent_names, \
.num_parents = ARRAY_SIZE(_parent_names), \
.parents = _parents, \
.flags = _flags | CLK_IS_BASIC, \
}
#define DEFINE_CLK_FIXED_RATE(_name, _flags, _rate, \
_fixed_rate_flags) \
static struct clk _name; \
static const char *_name##_parent_names[] = {}; \
static struct clk_fixed_rate _name##_hw = { \
.hw = { \
.clk = &_name, \
}, \
.fixed_rate = _rate, \
.flags = _fixed_rate_flags, \
}; \
DEFINE_CLK(_name, clk_fixed_rate_ops, _flags, \
_name##_parent_names, NULL);
#define DEFINE_CLK_GATE(_name, _parent_name, _parent_ptr, \
_flags, _reg, _bit_idx, \
_gate_flags, _lock) \
static struct clk _name; \
static const char *_name##_parent_names[] = { \
_parent_name, \
}; \
static struct clk *_name##_parents[] = { \
_parent_ptr, \
}; \
static struct clk_gate _name##_hw = { \
.hw = { \
.clk = &_name, \
}, \
.reg = _reg, \
.bit_idx = _bit_idx, \
.flags = _gate_flags, \
.lock = _lock, \
}; \
DEFINE_CLK(_name, clk_gate_ops, _flags, \
_name##_parent_names, _name##_parents);
#define _DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \
_flags, _reg, _shift, _width, \
_divider_flags, _table, _lock) \
static struct clk _name; \
static const char *_name##_parent_names[] = { \
_parent_name, \
}; \
static struct clk *_name##_parents[] = { \
_parent_ptr, \
}; \
static struct clk_divider _name##_hw = { \
.hw = { \
.clk = &_name, \
}, \
.reg = _reg, \
.shift = _shift, \
.width = _width, \
.flags = _divider_flags, \
.table = _table, \
.lock = _lock, \
}; \
DEFINE_CLK(_name, clk_divider_ops, _flags, \
_name##_parent_names, _name##_parents);
#define DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \
_flags, _reg, _shift, _width, \
_divider_flags, _lock) \
_DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \
_flags, _reg, _shift, _width, \
_divider_flags, NULL, _lock)
#define DEFINE_CLK_DIVIDER_TABLE(_name, _parent_name, \
_parent_ptr, _flags, _reg, \
_shift, _width, _divider_flags, \
_table, _lock) \
_DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \
_flags, _reg, _shift, _width, \
_divider_flags, _table, _lock) \
#define DEFINE_CLK_MUX(_name, _parent_names, _parents, _flags, \
_reg, _shift, _width, \
_mux_flags, _lock) \
static struct clk _name; \
static struct clk_mux _name##_hw = { \
.hw = { \
.clk = &_name, \
}, \
.reg = _reg, \
.shift = _shift, \
.mask = BIT(_width) - 1, \
.flags = _mux_flags, \
.lock = _lock, \
}; \
DEFINE_CLK(_name, clk_mux_ops, _flags, _parent_names, \
_parents);
#define DEFINE_CLK_FIXED_FACTOR(_name, _parent_name, \
_parent_ptr, _flags, \
_mult, _div) \
static struct clk _name; \
static const char *_name##_parent_names[] = { \
_parent_name, \
}; \
static struct clk *_name##_parents[] = { \
_parent_ptr, \
}; \
static struct clk_fixed_factor _name##_hw = { \
.hw = { \
.clk = &_name, \
}, \
.mult = _mult, \
.div = _div, \
}; \
DEFINE_CLK(_name, clk_fixed_factor_ops, _flags, \
_name##_parent_names, _name##_parents);
/**
* __clk_init - initialize the data structures in a struct clk
* @dev: device initializing this clk, placeholder for now
* @clk: clk being initialized
*
* Initializes the lists in struct clk, queries the hardware for the
* parent and rate and sets them both.
*
* Any struct clk passed into __clk_init must have the following members
* populated:
* .name
* .ops
* .hw
* .parent_names
* .num_parents
* .flags
*
* It is not necessary to call clk_register if __clk_init is used directly with
* statically initialized clock data.
*
* Returns 0 on success, otherwise an error code.
*/
int __clk_init(struct device *dev, struct clk *clk);
struct clk *__clk_register(struct device *dev, struct clk_hw *hw);
#endif /* CONFIG_COMMON_CLK */
#endif /* CLK_PRIVATE_H */