1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * pervasive backend for the cbe_cpufreq driver 4 * 5 * This driver makes use of the pervasive unit to 6 * engage the desired frequency. 7 * 8 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007 9 * 10 * Author: Christian Krafft <krafft@de.ibm.com> 11 */ 12 13 #include <linux/io.h> 14 #include <linux/kernel.h> 15 #include <linux/time.h> 16 #include <asm/machdep.h> 17 #include <asm/hw_irq.h> 18 #include <asm/cell-regs.h> 19 20 #include "ppc_cbe_cpufreq.h" 21 22 /* to write to MIC register */ 23 static u64 MIC_Slow_Fast_Timer_table[] = { 24 [0 ... 7] = 0x007fc00000000000ull, 25 }; 26 27 /* more values for the MIC */ 28 static u64 MIC_Slow_Next_Timer_table[] = { 29 0x0000240000000000ull, 30 0x0000268000000000ull, 31 0x000029C000000000ull, 32 0x00002D0000000000ull, 33 0x0000300000000000ull, 34 0x0000334000000000ull, 35 0x000039C000000000ull, 36 0x00003FC000000000ull, 37 }; 38 39 40 int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode) 41 { 42 struct cbe_pmd_regs __iomem *pmd_regs; 43 struct cbe_mic_tm_regs __iomem *mic_tm_regs; 44 unsigned long flags; 45 u64 value; 46 #ifdef DEBUG 47 long time; 48 #endif 49 50 local_irq_save(flags); 51 52 mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu); 53 pmd_regs = cbe_get_cpu_pmd_regs(cpu); 54 55 #ifdef DEBUG 56 time = jiffies; 57 #endif 58 59 out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]); 60 out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]); 61 62 out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]); 63 out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]); 64 65 value = in_be64(&pmd_regs->pmcr); 66 /* set bits to zero */ 67 value &= 0xFFFFFFFFFFFFFFF8ull; 68 /* set bits to next pmode */ 69 value |= pmode; 70 71 out_be64(&pmd_regs->pmcr, value); 72 73 #ifdef DEBUG 74 /* wait until new pmode appears in status register */ 75 value = in_be64(&pmd_regs->pmsr) & 0x07; 76 while (value != pmode) { 77 cpu_relax(); 78 value = in_be64(&pmd_regs->pmsr) & 0x07; 79 } 80 81 time = jiffies - time; 82 time = jiffies_to_msecs(time); 83 pr_debug("had to wait %lu ms for a transition using " \ 84 "pervasive unit\n", time); 85 #endif 86 local_irq_restore(flags); 87 88 return 0; 89 } 90 91 92 int cbe_cpufreq_get_pmode(int cpu) 93 { 94 int ret; 95 struct cbe_pmd_regs __iomem *pmd_regs; 96 97 pmd_regs = cbe_get_cpu_pmd_regs(cpu); 98 ret = in_be64(&pmd_regs->pmsr) & 0x07; 99 100 return ret; 101 } 102 103