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/*
* Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/types.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <mach/spba.h>
/*!
* @file plat-mxc/spba.c
*
* @brief This file contains the SPBA API implementation details.
*
* @ingroup SPBA
*/
static DEFINE_SPINLOCK(spba_lock);
#define SPBA_MASTER_MIN 1
#define SPBA_MASTER_MAX 7
/*!
* the base addresses for the SPBA modules
*/
static unsigned long spba_base = (unsigned long)IO_ADDRESS(SPBA_CTRL_BASE_ADDR);
/*!
* SPBA clock
*/
static struct clk *spba_clk;
/*!
* This function allows the three masters (A, B, C) to take ownership of a
* shared peripheral.
*
* @param mod specified module as defined in \b enum \b #spba_module
* @param master one of more (or-ed together) masters as defined in \b enum \b #spba_masters
*
* @return 0 if successful; -1 otherwise.
*/
int spba_take_ownership(int mod, int master)
{
unsigned long spba_flags;
__u32 rtn_val = -1;
if (master < SPBA_MASTER_MIN || master > SPBA_MASTER_MAX) {
printk("spba_take_ownership() invalide master= %d\n", master);
BUG(); /* oops */
}
if (spba_clk == NULL)
spba_clk = clk_get(NULL, "spba_clk");
clk_enable(spba_clk);
spin_lock_irqsave(&spba_lock, spba_flags);
__raw_writel(master, spba_base + mod);
if ((__raw_readl(spba_base + mod) & MXC_SPBA_RAR_MASK) == master) {
rtn_val = 0;
}
spin_unlock_irqrestore(&spba_lock, spba_flags);
clk_disable(spba_clk);
return rtn_val;
}
/*!
* This function releases the ownership for a shared peripheral.
*
* @param mod specified module as defined in \b enum \b #spba_module
* @param master one of more (or-ed together) masters as defined in \b enum \b #spba_masters
*
* @return 0 if successful; -1 otherwise.
*/
int spba_rel_ownership(int mod, int master)
{
unsigned long spba_flags;
volatile unsigned long rar;
if (master < SPBA_MASTER_MIN || master > SPBA_MASTER_MAX) {
printk("spba_take_ownership() invalide master= %d\n", master);
BUG(); /* oops */
}
if (spba_clk == NULL)
spba_clk = clk_get(NULL, "spba_clk");
clk_enable(spba_clk);
if ((__raw_readl(spba_base + mod) & master) == 0) {
clk_disable(spba_clk);
return 0; /* does not own it */
}
spin_lock_irqsave(&spba_lock, spba_flags);
/* Since only the last 3 bits are writeable, doesn't need to mask off
bits 31-3 */
rar = __raw_readl(spba_base + mod) & (~master);
__raw_writel(rar, spba_base + mod);
if ((__raw_readl(spba_base + mod) & master) != 0) {
spin_unlock_irqrestore(&spba_lock, spba_flags);
clk_disable(spba_clk);
return -1;
}
spin_unlock_irqrestore(&spba_lock, spba_flags);
clk_disable(spba_clk);
return 0;
}
EXPORT_SYMBOL(spba_take_ownership);
EXPORT_SYMBOL(spba_rel_ownership);
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("SPBA");
MODULE_LICENSE("GPL");
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