linux-sg2042/arch/arm/mach-bcmring/clock.c

224 lines
5.0 KiB
C

/*****************************************************************************
* Copyright 2001 - 2009 Broadcom Corporation. All rights reserved.
*
* Unless you and Broadcom execute a separate written software license
* agreement governing use of this software, this software is licensed to you
* under the terms of the GNU General Public License version 2, available at
* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
*
* Notwithstanding the above, under no circumstances may you combine this
* software in any way with any other Broadcom software provided under a
* license other than the GPL, without Broadcom's express prior written
* consent.
*****************************************************************************/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/clk.h>
#include <linux/spinlock.h>
#include <linux/clkdev.h>
#include <mach/csp/hw_cfg.h>
#include <mach/csp/chipcHw_def.h>
#include <mach/csp/chipcHw_reg.h>
#include <mach/csp/chipcHw_inline.h>
#include "clock.h"
#define clk_is_primary(x) ((x)->type & CLK_TYPE_PRIMARY)
#define clk_is_pll1(x) ((x)->type & CLK_TYPE_PLL1)
#define clk_is_pll2(x) ((x)->type & CLK_TYPE_PLL2)
#define clk_is_programmable(x) ((x)->type & CLK_TYPE_PROGRAMMABLE)
#define clk_is_bypassable(x) ((x)->type & CLK_TYPE_BYPASSABLE)
#define clk_is_using_xtal(x) ((x)->mode & CLK_MODE_XTAL)
static DEFINE_SPINLOCK(clk_lock);
static void __clk_enable(struct clk *clk)
{
if (!clk)
return;
/* enable parent clock first */
if (clk->parent)
__clk_enable(clk->parent);
if (clk->use_cnt++ == 0) {
if (clk_is_pll1(clk)) { /* PLL1 */
chipcHw_pll1Enable(clk->rate_hz, 0);
} else if (clk_is_pll2(clk)) { /* PLL2 */
chipcHw_pll2Enable(clk->rate_hz);
} else if (clk_is_using_xtal(clk)) { /* source is crystal */
if (!clk_is_primary(clk))
chipcHw_bypassClockEnable(clk->csp_id);
} else { /* source is PLL */
chipcHw_setClockEnable(clk->csp_id);
}
}
}
int clk_enable(struct clk *clk)
{
unsigned long flags;
if (!clk)
return -EINVAL;
spin_lock_irqsave(&clk_lock, flags);
__clk_enable(clk);
spin_unlock_irqrestore(&clk_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_enable);
static void __clk_disable(struct clk *clk)
{
if (!clk)
return;
BUG_ON(clk->use_cnt == 0);
if (--clk->use_cnt == 0) {
if (clk_is_pll1(clk)) { /* PLL1 */
chipcHw_pll1Disable();
} else if (clk_is_pll2(clk)) { /* PLL2 */
chipcHw_pll2Disable();
} else if (clk_is_using_xtal(clk)) { /* source is crystal */
if (!clk_is_primary(clk))
chipcHw_bypassClockDisable(clk->csp_id);
} else { /* source is PLL */
chipcHw_setClockDisable(clk->csp_id);
}
}
if (clk->parent)
__clk_disable(clk->parent);
}
void clk_disable(struct clk *clk)
{
unsigned long flags;
if (!clk)
return;
spin_lock_irqsave(&clk_lock, flags);
__clk_disable(clk);
spin_unlock_irqrestore(&clk_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
if (!clk)
return 0;
return clk->rate_hz;
}
EXPORT_SYMBOL(clk_get_rate);
long clk_round_rate(struct clk *clk, unsigned long rate)
{
unsigned long flags;
unsigned long actual;
unsigned long rate_hz;
if (!clk)
return -EINVAL;
if (!clk_is_programmable(clk))
return -EINVAL;
if (clk->use_cnt)
return -EBUSY;
spin_lock_irqsave(&clk_lock, flags);
actual = clk->parent->rate_hz;
rate_hz = min(actual, rate);
spin_unlock_irqrestore(&clk_lock, flags);
return rate_hz;
}
EXPORT_SYMBOL(clk_round_rate);
int clk_set_rate(struct clk *clk, unsigned long rate)
{
unsigned long flags;
unsigned long actual;
unsigned long rate_hz;
if (!clk)
return -EINVAL;
if (!clk_is_programmable(clk))
return -EINVAL;
if (clk->use_cnt)
return -EBUSY;
spin_lock_irqsave(&clk_lock, flags);
actual = clk->parent->rate_hz;
rate_hz = min(actual, rate);
rate_hz = chipcHw_setClockFrequency(clk->csp_id, rate_hz);
clk->rate_hz = rate_hz;
spin_unlock_irqrestore(&clk_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_set_rate);
struct clk *clk_get_parent(struct clk *clk)
{
if (!clk)
return NULL;
return clk->parent;
}
EXPORT_SYMBOL(clk_get_parent);
int clk_set_parent(struct clk *clk, struct clk *parent)
{
unsigned long flags;
struct clk *old_parent;
if (!clk || !parent)
return -EINVAL;
if (!clk_is_primary(parent) || !clk_is_bypassable(clk))
return -EINVAL;
/* if more than one user, parent is not allowed */
if (clk->use_cnt > 1)
return -EBUSY;
if (clk->parent == parent)
return 0;
spin_lock_irqsave(&clk_lock, flags);
old_parent = clk->parent;
clk->parent = parent;
if (clk_is_using_xtal(parent))
clk->mode |= CLK_MODE_XTAL;
else
clk->mode &= (~CLK_MODE_XTAL);
/* if clock is active */
if (clk->use_cnt != 0) {
clk->use_cnt--;
/* enable clock with the new parent */
__clk_enable(clk);
/* disable the old parent */
__clk_disable(old_parent);
}
spin_unlock_irqrestore(&clk_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_set_parent);