1/*
  2 * pervasive backend for the cbe_cpufreq driver
  3 *
  4 * This driver makes use of the pervasive unit to
  5 * engage the desired frequency.
  6 *
  7 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
  8 *
  9 * Author: Christian Krafft <krafft@de.ibm.com>
 10 *
 11 * This program is free software; you can redistribute it and/or modify
 12 * it under the terms of the GNU General Public License as published by
 13 * the Free Software Foundation; either version 2, or (at your option)
 14 * any later version.
 15 *
 16 * This program is distributed in the hope that it will be useful,
 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 19 * GNU General Public License for more details.
 20 *
 21 * You should have received a copy of the GNU General Public License
 22 * along with this program; if not, write to the Free Software
 23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 24 */
 25
 26#include <linux/io.h>
 27#include <linux/kernel.h>
 28#include <linux/time.h>
 29#include <asm/machdep.h>
 30#include <asm/hw_irq.h>
 31#include <asm/cell-regs.h>
 32
 33#include "ppc_cbe_cpufreq.h"
 34
 35/* to write to MIC register */
 36static u64 MIC_Slow_Fast_Timer_table[] = {
 37	[0 ... 7] = 0x007fc00000000000ull,
 38};
 39
 40/* more values for the MIC */
 41static u64 MIC_Slow_Next_Timer_table[] = {
 42	0x0000240000000000ull,
 43	0x0000268000000000ull,
 44	0x000029C000000000ull,
 45	0x00002D0000000000ull,
 46	0x0000300000000000ull,
 47	0x0000334000000000ull,
 48	0x000039C000000000ull,
 49	0x00003FC000000000ull,
 50};
 51
 52
 53int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode)
 54{
 55	struct cbe_pmd_regs __iomem *pmd_regs;
 56	struct cbe_mic_tm_regs __iomem *mic_tm_regs;
 57	unsigned long flags;
 58	u64 value;
 59#ifdef DEBUG
 60	long time;
 61#endif
 62
 63	local_irq_save(flags);
 64
 65	mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
 66	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
 67
 68#ifdef DEBUG
 69	time = jiffies;
 70#endif
 71
 72	out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
 73	out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
 74
 75	out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
 76	out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
 77
 78	value = in_be64(&pmd_regs->pmcr);
 79	/* set bits to zero */
 80	value &= 0xFFFFFFFFFFFFFFF8ull;
 81	/* set bits to next pmode */
 82	value |= pmode;
 83
 84	out_be64(&pmd_regs->pmcr, value);
 85
 86#ifdef DEBUG
 87	/* wait until new pmode appears in status register */
 88	value = in_be64(&pmd_regs->pmsr) & 0x07;
 89	while (value != pmode) {
 90		cpu_relax();
 91		value = in_be64(&pmd_regs->pmsr) & 0x07;
 92	}
 93
 94	time = jiffies  - time;
 95	time = jiffies_to_msecs(time);
 96	pr_debug("had to wait %lu ms for a transition using " \
 97		 "pervasive unit\n", time);
 98#endif
 99	local_irq_restore(flags);
100
101	return 0;
102}
103
104
105int cbe_cpufreq_get_pmode(int cpu)
106{
107	int ret;
108	struct cbe_pmd_regs __iomem *pmd_regs;
109
110	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
111	ret = in_be64(&pmd_regs->pmsr) & 0x07;
112
113	return ret;
114}
115