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