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(unsigned int irq) 40 { 41 } 42 43 static void disable_rt_irq(unsigned int irq) 44 { 45 } 46 47 static struct irq_chip rt_irq_type = { 48 .name = "SN HUB RT timer", 49 .ack = disable_rt_irq, 50 .mask = disable_rt_irq, 51 .mask_ack = disable_rt_irq, 52 .unmask = enable_rt_irq, 53 .eoi = enable_rt_irq, 54 }; 55 56 static int rt_next_event(unsigned long delta, struct clock_event_device *evt) 57 { 58 unsigned int cpu = smp_processor_id(); 59 int slice = cputoslice(cpu); 60 unsigned long cnt; 61 62 cnt = LOCAL_HUB_L(PI_RT_COUNT); 63 cnt += delta; 64 LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt); 65 66 return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; 67 } 68 69 static void rt_set_mode(enum clock_event_mode mode, 70 struct clock_event_device *evt) 71 { 72 switch (mode) { 73 case CLOCK_EVT_MODE_ONESHOT: 74 /* The only mode supported */ 75 break; 76 77 case CLOCK_EVT_MODE_PERIODIC: 78 case CLOCK_EVT_MODE_UNUSED: 79 case CLOCK_EVT_MODE_SHUTDOWN: 80 case CLOCK_EVT_MODE_RESUME: 81 /* Nothing to do */ 82 break; 83 } 84 } 85 86 int rt_timer_irq; 87 88 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent); 89 static DEFINE_PER_CPU(char [11], hub_rt_name); 90 91 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id) 92 { 93 unsigned int cpu = smp_processor_id(); 94 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 95 int slice = cputoslice(cpu); 96 97 /* 98 * Ack 99 */ 100 LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0); 101 cd->event_handler(cd); 102 103 return IRQ_HANDLED; 104 } 105 106 struct irqaction hub_rt_irqaction = { 107 .handler = hub_rt_counter_handler, 108 .flags = IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER, 109 .name = "hub-rt", 110 }; 111 112 /* 113 * This is a hack; we really need to figure these values out dynamically 114 * 115 * Since 800 ns works very well with various HUB frequencies, such as 116 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. 117 * 118 * Ralf: which clock rate is used to feed the counter? 119 */ 120 #define NSEC_PER_CYCLE 800 121 #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) 122 123 void __cpuinit hub_rt_clock_event_init(void) 124 { 125 unsigned int cpu = smp_processor_id(); 126 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 127 unsigned char *name = per_cpu(hub_rt_name, cpu); 128 int irq = rt_timer_irq; 129 130 sprintf(name, "hub-rt %d", cpu); 131 cd->name = name; 132 cd->features = CLOCK_EVT_FEAT_ONESHOT; 133 clockevent_set_clock(cd, CYCLES_PER_SEC); 134 cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd); 135 cd->min_delta_ns = clockevent_delta2ns(0x300, cd); 136 cd->rating = 200; 137 cd->irq = irq; 138 cd->cpumask = cpumask_of(cpu); 139 cd->set_next_event = rt_next_event; 140 cd->set_mode = rt_set_mode; 141 clockevents_register_device(cd); 142 } 143 144 static void __init hub_rt_clock_event_global_init(void) 145 { 146 int irq; 147 148 do { 149 smp_wmb(); 150 irq = rt_timer_irq; 151 if (irq) 152 break; 153 154 irq = allocate_irqno(); 155 if (irq < 0) 156 panic("Allocation of irq number for timer failed"); 157 } while (xchg(&rt_timer_irq, irq)); 158 159 set_irq_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq); 160 setup_irq(irq, &hub_rt_irqaction); 161 } 162 163 static cycle_t hub_rt_read(struct clocksource *cs) 164 { 165 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 166 } 167 168 struct clocksource hub_rt_clocksource = { 169 .name = "HUB-RT", 170 .rating = 200, 171 .read = hub_rt_read, 172 .mask = CLOCKSOURCE_MASK(52), 173 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 174 }; 175 176 static void __init hub_rt_clocksource_init(void) 177 { 178 struct clocksource *cs = &hub_rt_clocksource; 179 180 clocksource_register_hz(cs, CYCLES_PER_SEC); 181 } 182 183 void __init plat_time_init(void) 184 { 185 hub_rt_clocksource_init(); 186 hub_rt_clock_event_global_init(); 187 hub_rt_clock_event_init(); 188 } 189 190 void __cpuinit cpu_time_init(void) 191 { 192 lboard_t *board; 193 klcpu_t *cpu; 194 int cpuid; 195 196 /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */ 197 board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27); 198 if (!board) 199 panic("Can't find board info for myself."); 200 201 cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX; 202 cpu = (klcpu_t *) KLCF_COMP(board, cpuid); 203 if (!cpu) 204 panic("No information about myself?"); 205 206 printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed); 207 208 set_c0_status(SRB_TIMOCLK); 209 } 210 211 void __cpuinit hub_rtc_init(cnodeid_t cnode) 212 { 213 214 /* 215 * We only need to initialize the current node. 216 * If this is not the current node then it is a cpuless 217 * node and timeouts will not happen there. 218 */ 219 if (get_compact_nodeid() == cnode) { 220 LOCAL_HUB_S(PI_RT_EN_A, 1); 221 LOCAL_HUB_S(PI_RT_EN_B, 1); 222 LOCAL_HUB_S(PI_PROF_EN_A, 0); 223 LOCAL_HUB_S(PI_PROF_EN_B, 0); 224 LOCAL_HUB_S(PI_RT_COUNT, 0); 225 LOCAL_HUB_S(PI_RT_PEND_A, 0); 226 LOCAL_HUB_S(PI_RT_PEND_B, 0); 227 } 228 } 229 230 static int __init sgi_ip27_rtc_devinit(void) 231 { 232 struct resource res; 233 234 memset(&res, 0, sizeof(res)); 235 res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + 236 IOC3_BYTEBUS_DEV0); 237 res.end = res.start + 32767; 238 res.flags = IORESOURCE_MEM; 239 240 return IS_ERR(platform_device_register_simple("rtc-m48t35", -1, 241 &res, 1)); 242 } 243 244 /* 245 * kludge make this a device_initcall after ioc3 resource conflicts 246 * are resolved 247 */ 248 late_initcall(sgi_ip27_rtc_devinit); 249