1 #include <linux/module.h> 2 #include <linux/smp.h> 3 #include <linux/time.h> 4 #include <linux/errno.h> 5 #include <linux/timex.h> 6 #include <linux/clocksource.h> 7 #include <linux/io.h> 8 9 /* IBM Summit (EXA) Cyclone counter code*/ 10 #define CYCLONE_CBAR_ADDR 0xFEB00CD0 11 #define CYCLONE_PMCC_OFFSET 0x51A0 12 #define CYCLONE_MPMC_OFFSET 0x51D0 13 #define CYCLONE_MPCS_OFFSET 0x51A8 14 #define CYCLONE_TIMER_FREQ 100000000 15 16 int use_cyclone; 17 void __init cyclone_setup(void) 18 { 19 use_cyclone = 1; 20 } 21 22 static void __iomem *cyclone_mc; 23 24 static cycle_t read_cyclone(struct clocksource *cs) 25 { 26 return (cycle_t)readq((void __iomem *)cyclone_mc); 27 } 28 29 static struct clocksource clocksource_cyclone = { 30 .name = "cyclone", 31 .rating = 300, 32 .read = read_cyclone, 33 .mask = (1LL << 40) - 1, 34 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 35 }; 36 37 int __init init_cyclone_clock(void) 38 { 39 u64 __iomem *reg; 40 u64 base; /* saved cyclone base address */ 41 u64 offset; /* offset from pageaddr to cyclone_timer register */ 42 int i; 43 u32 __iomem *cyclone_timer; /* Cyclone MPMC0 register */ 44 45 if (!use_cyclone) 46 return 0; 47 48 printk(KERN_INFO "Summit chipset: Starting Cyclone Counter.\n"); 49 50 /* find base address */ 51 offset = (CYCLONE_CBAR_ADDR); 52 reg = ioremap_nocache(offset, sizeof(u64)); 53 if(!reg){ 54 printk(KERN_ERR "Summit chipset: Could not find valid CBAR" 55 " register.\n"); 56 use_cyclone = 0; 57 return -ENODEV; 58 } 59 base = readq(reg); 60 iounmap(reg); 61 if(!base){ 62 printk(KERN_ERR "Summit chipset: Could not find valid CBAR" 63 " value.\n"); 64 use_cyclone = 0; 65 return -ENODEV; 66 } 67 68 /* setup PMCC */ 69 offset = (base + CYCLONE_PMCC_OFFSET); 70 reg = ioremap_nocache(offset, sizeof(u64)); 71 if(!reg){ 72 printk(KERN_ERR "Summit chipset: Could not find valid PMCC" 73 " register.\n"); 74 use_cyclone = 0; 75 return -ENODEV; 76 } 77 writel(0x00000001,reg); 78 iounmap(reg); 79 80 /* setup MPCS */ 81 offset = (base + CYCLONE_MPCS_OFFSET); 82 reg = ioremap_nocache(offset, sizeof(u64)); 83 if(!reg){ 84 printk(KERN_ERR "Summit chipset: Could not find valid MPCS" 85 " register.\n"); 86 use_cyclone = 0; 87 return -ENODEV; 88 } 89 writel(0x00000001,reg); 90 iounmap(reg); 91 92 /* map in cyclone_timer */ 93 offset = (base + CYCLONE_MPMC_OFFSET); 94 cyclone_timer = ioremap_nocache(offset, sizeof(u32)); 95 if(!cyclone_timer){ 96 printk(KERN_ERR "Summit chipset: Could not find valid MPMC" 97 " register.\n"); 98 use_cyclone = 0; 99 return -ENODEV; 100 } 101 102 /*quick test to make sure its ticking*/ 103 for(i=0; i<3; i++){ 104 u32 old = readl(cyclone_timer); 105 int stall = 100; 106 while(stall--) barrier(); 107 if(readl(cyclone_timer) == old){ 108 printk(KERN_ERR "Summit chipset: Counter not counting!" 109 " DISABLED\n"); 110 iounmap(cyclone_timer); 111 cyclone_timer = NULL; 112 use_cyclone = 0; 113 return -ENODEV; 114 } 115 } 116 /* initialize last tick */ 117 cyclone_mc = cyclone_timer; 118 clocksource_cyclone.archdata.fsys_mmio = cyclone_timer; 119 clocksource_register_hz(&clocksource_cyclone, CYCLONE_TIMER_FREQ); 120 121 return 0; 122 } 123 124 __initcall(init_cyclone_clock); 125