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