satip-axe/kernel/include/linux/stm/clk.h
2015-03-26 17:24:57 +01:00

109 lines
2.7 KiB
C

/*
* STMicroelectronics clock framework
*
* Copyright (C) 2009, STMicroelectronics
* Copyright (C) 2010, STMicroelectronics
* Author: Francesco M. Virlinzi <francesco.virlinzi@st.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#ifndef __ASM_STM_CLK_H__
#define __ASM_STM_CLK_H__
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/seq_file.h>
#include <linux/clk.h>
#include <linux/spinlock.h>
struct clk;
struct clk_ops {
int (*init)(struct clk *clk);
int (*enable)(struct clk *clk);
int (*disable)(struct clk *clk);
int (*set_rate)(struct clk *clk, unsigned long rate);
int (*set_parent)(struct clk *clk, struct clk *parent);
int (*recalc)(struct clk *clk);
long (*round_rate)(struct clk *clk, unsigned long rate);
int (*observe)(struct clk *clk, unsigned long *div);
unsigned long (*get_measure)(struct clk *clk);
};
struct clk {
struct list_head node;
const char *name;
int id;
struct clk *parent;
struct clk_ops *ops;
void *private_data;
struct kref kref;
unsigned long usage_counter;
unsigned long rate;
unsigned long flags;
struct list_head children;
struct list_head children_node;
};
#define CLK_ALWAYS_ENABLED (1 << 0)
/* drivers/stm/clks/clock-... */
/* SoC specific clock initialisation */
int plat_clk_init(void);
int plat_clk_alias_init(void);
/* drivers/stm/clk.c */
/* Additions to the standard clk_... functions in include/linux/clk.h */
int clk_register(struct clk *);
void clk_unregister(struct clk *);
int clk_for_each(int (*fn)(struct clk *clk, void *data), void *data);
int clk_for_each_child(struct clk *clk,
int (*fn)(struct clk *clk, void *data), void *data);
static inline void recalculate_root_clocks(void)
{}
static inline void clk_enable_init_clocks(void)
{}
/**
* clk_observe - route the clock to an external pin (if possible)
* @clk: clock source
* @div: divider
*
* To help with debugging clock related code, it is sometimes possible
* to route the clock directly to an external pin where it can be
* observed, typically with an oscilloscope.
*
* To allow high frequency clocks to be observed it is sometimes
* possible to divide the clock by a fixed amount before it is sent
* to an external pin. This factor is specified by @div, which is also
* used to return the actual divider used, which may not be the requested
* factor.
*/
int clk_observe(struct clk *clk, unsigned long *div);
/**
* clk_get_measure - evaluate the clock rate in hardware (if possible)
* @clk: clock source
*
* Measure the frequency of the specified clock and return it.
*/
unsigned long clk_get_measure(struct clk *clk);
#endif /* __ASM_STM_CLOCK_H */