1 /* 2 * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org) 3 * Copytight (C) 1999, 2000 Silicon Graphics, Inc. 4 */ 5 #include <linux/bcd.h> 6 #include <linux/clockchips.h> 7 #include <linux/init.h> 8 #include <linux/kernel.h> 9 #include <linux/sched.h> 10 #include <linux/interrupt.h> 11 #include <linux/kernel_stat.h> 12 #include <linux/param.h> 13 #include <linux/smp.h> 14 #include <linux/time.h> 15 #include <linux/timex.h> 16 #include <linux/mm.h> 17 #include <linux/platform_device.h> 18 19 #include <asm/time.h> 20 #include <asm/pgtable.h> 21 #include <asm/sgialib.h> 22 #include <asm/sn/ioc3.h> 23 #include <asm/sn/klconfig.h> 24 #include <asm/sn/arch.h> 25 #include <asm/sn/addrs.h> 26 #include <asm/sn/sn_private.h> 27 #include <asm/sn/sn0/ip27.h> 28 #include <asm/sn/sn0/hub.h> 29 30 #define TICK_SIZE (tick_nsec / 1000) 31 32 /* Includes for ioc3_init(). */ 33 #include <asm/sn/types.h> 34 #include <asm/sn/sn0/addrs.h> 35 #include <asm/sn/sn0/hubni.h> 36 #include <asm/sn/sn0/hubio.h> 37 #include <asm/pci/bridge.h> 38 39 static void enable_rt_irq(struct irq_data *d) 40 { 41 } 42 43 static void disable_rt_irq(struct irq_data *d) 44 { 45 } 46 47 static struct irq_chip rt_irq_type = { 48 .name = "SN HUB RT timer", 49 .irq_mask = disable_rt_irq, 50 .irq_unmask = enable_rt_irq, 51 }; 52 53 static int rt_next_event(unsigned long delta, struct clock_event_device *evt) 54 { 55 unsigned int cpu = smp_processor_id(); 56 int slice = cputoslice(cpu); 57 unsigned long cnt; 58 59 cnt = LOCAL_HUB_L(PI_RT_COUNT); 60 cnt += delta; 61 LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt); 62 63 return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; 64 } 65 66 static void rt_set_mode(enum clock_event_mode mode, 67 struct clock_event_device *evt) 68 { 69 /* Nothing to do ... */ 70 } 71 72 unsigned int rt_timer_irq; 73 74 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent); 75 static DEFINE_PER_CPU(char [11], hub_rt_name); 76 77 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id) 78 { 79 unsigned int cpu = smp_processor_id(); 80 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 81 int slice = cputoslice(cpu); 82 83 /* 84 * Ack 85 */ 86 LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0); 87 cd->event_handler(cd); 88 89 return IRQ_HANDLED; 90 } 91 92 struct irqaction hub_rt_irqaction = { 93 .handler = hub_rt_counter_handler, 94 .flags = IRQF_PERCPU | IRQF_TIMER, 95 .name = "hub-rt", 96 }; 97 98 /* 99 * This is a hack; we really need to figure these values out dynamically 100 * 101 * Since 800 ns works very well with various HUB frequencies, such as 102 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. 103 * 104 * Ralf: which clock rate is used to feed the counter? 105 */ 106 #define NSEC_PER_CYCLE 800 107 #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) 108 109 void hub_rt_clock_event_init(void) 110 { 111 unsigned int cpu = smp_processor_id(); 112 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 113 unsigned char *name = per_cpu(hub_rt_name, cpu); 114 int irq = rt_timer_irq; 115 116 sprintf(name, "hub-rt %d", cpu); 117 cd->name = name; 118 cd->features = CLOCK_EVT_FEAT_ONESHOT; 119 clockevent_set_clock(cd, CYCLES_PER_SEC); 120 cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd); 121 cd->min_delta_ns = clockevent_delta2ns(0x300, cd); 122 cd->rating = 200; 123 cd->irq = irq; 124 cd->cpumask = cpumask_of(cpu); 125 cd->set_next_event = rt_next_event; 126 cd->set_mode = rt_set_mode; 127 clockevents_register_device(cd); 128 } 129 130 static void __init hub_rt_clock_event_global_init(void) 131 { 132 int irq; 133 134 do { 135 smp_wmb(); 136 irq = rt_timer_irq; 137 if (irq) 138 break; 139 140 irq = allocate_irqno(); 141 if (irq < 0) 142 panic("Allocation of irq number for timer failed"); 143 } while (xchg(&rt_timer_irq, irq)); 144 145 irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq); 146 setup_irq(irq, &hub_rt_irqaction); 147 } 148 149 static cycle_t hub_rt_read(struct clocksource *cs) 150 { 151 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 152 } 153 154 struct clocksource hub_rt_clocksource = { 155 .name = "HUB-RT", 156 .rating = 200, 157 .read = hub_rt_read, 158 .mask = CLOCKSOURCE_MASK(52), 159 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 160 }; 161 162 static void __init hub_rt_clocksource_init(void) 163 { 164 struct clocksource *cs = &hub_rt_clocksource; 165 166 clocksource_register_hz(cs, CYCLES_PER_SEC); 167 } 168 169 void __init plat_time_init(void) 170 { 171 hub_rt_clocksource_init(); 172 hub_rt_clock_event_global_init(); 173 hub_rt_clock_event_init(); 174 } 175 176 void cpu_time_init(void) 177 { 178 lboard_t *board; 179 klcpu_t *cpu; 180 int cpuid; 181 182 /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */ 183 board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27); 184 if (!board) 185 panic("Can't find board info for myself."); 186 187 cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX; 188 cpu = (klcpu_t *) KLCF_COMP(board, cpuid); 189 if (!cpu) 190 panic("No information about myself?"); 191 192 printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed); 193 194 set_c0_status(SRB_TIMOCLK); 195 } 196 197 void hub_rtc_init(cnodeid_t cnode) 198 { 199 200 /* 201 * We only need to initialize the current node. 202 * If this is not the current node then it is a cpuless 203 * node and timeouts will not happen there. 204 */ 205 if (get_compact_nodeid() == cnode) { 206 LOCAL_HUB_S(PI_RT_EN_A, 1); 207 LOCAL_HUB_S(PI_RT_EN_B, 1); 208 LOCAL_HUB_S(PI_PROF_EN_A, 0); 209 LOCAL_HUB_S(PI_PROF_EN_B, 0); 210 LOCAL_HUB_S(PI_RT_COUNT, 0); 211 LOCAL_HUB_S(PI_RT_PEND_A, 0); 212 LOCAL_HUB_S(PI_RT_PEND_B, 0); 213 } 214 } 215 216 static int __init sgi_ip27_rtc_devinit(void) 217 { 218 struct resource res; 219 220 memset(&res, 0, sizeof(res)); 221 res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + 222 IOC3_BYTEBUS_DEV0); 223 res.end = res.start + 32767; 224 res.flags = IORESOURCE_MEM; 225 226 return IS_ERR(platform_device_register_simple("rtc-m48t35", -1, 227 &res, 1)); 228 } 229 230 /* 231 * kludge make this a device_initcall after ioc3 resource conflicts 232 * are resolved 233 */ 234 late_initcall(sgi_ip27_rtc_devinit); 235