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 */ 36 static u64 MIC_Slow_Fast_Timer_table[] = { 37 [0 ... 7] = 0x007fc00000000000ull, 38 }; 39 40 /* more values for the MIC */ 41 static 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 53 int 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 } 103 104 105 int 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 } 115 116