/*
* pervasive backend for the cbe_cpufreq driver
*
* This driver makes use of the pervasive unit to
* engage the desired frequency.
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
*
* Author: Christian Krafft <krafft@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <asm/machdep.h>
#include <asm/hw_irq.h>
#include <asm/cell-regs.h>
#include "cbe_cpufreq.h"
/* to write to MIC register */
static u64 MIC_Slow_Fast_Timer_table[] = {
[0 ... 7] = 0x007fc00000000000ull,
};
/* more values for the MIC */
static u64 MIC_Slow_Next_Timer_table[] = {
0x0000240000000000ull,
0x0000268000000000ull,
0x000029C000000000ull,
0x00002D0000000000ull,
0x0000300000000000ull,
0x0000334000000000ull,
0x000039C000000000ull,
0x00003FC000000000ull,
};
int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode)
{
struct cbe_pmd_regs __iomem *pmd_regs;
struct cbe_mic_tm_regs __iomem *mic_tm_regs;
u64 flags;
u64 value;
#ifdef DEBUG
long time;
#endif
local_irq_save(flags);
mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
pmd_regs = cbe_get_cpu_pmd_regs(cpu);
#ifdef DEBUG
time = jiffies;
#endif
out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
value = in_be64(&pmd_regs->pmcr);
/* set bits to zero */
value &= 0xFFFFFFFFFFFFFFF8ull;
/* set bits to next pmode */
value |= pmode;
out_be64(&pmd_regs->pmcr, value);
#ifdef DEBUG
/* wait until new pmode appears in status register */
value = in_be64(&pmd_regs->pmsr) & 0x07;
while (value != pmode) {
cpu_relax();
value = in_be64(&pmd_regs->pmsr) & 0x07;
}
time = jiffies - time;
time = jiffies_to_msecs(time);
pr_debug("had to wait %lu ms for a transition using " \
"pervasive unit\n", time);
#endif
local_irq_restore(flags);
return 0;
}
int cbe_cpufreq_get_pmode(int cpu)
{
int ret;
struct cbe_pmd_regs __iomem *pmd_regs;
pmd_regs = cbe_get_cpu_pmd_regs(cpu);
ret = in_be64(&pmd_regs->pmsr) & 0x07;
return ret;
}
