1 /* 2 * Copyright (C) 2000, 2001 Broadcom Corporation 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 17 */ 18 #include <linux/clockchips.h> 19 #include <linux/interrupt.h> 20 #include <linux/irq.h> 21 #include <linux/percpu.h> 22 #include <linux/smp.h> 23 24 #include <asm/addrspace.h> 25 #include <asm/io.h> 26 #include <asm/time.h> 27 28 #include <asm/sibyte/sb1250.h> 29 #include <asm/sibyte/sb1250_regs.h> 30 #include <asm/sibyte/sb1250_int.h> 31 #include <asm/sibyte/sb1250_scd.h> 32 33 #define IMR_IP2_VAL K_INT_MAP_I0 34 #define IMR_IP3_VAL K_INT_MAP_I1 35 #define IMR_IP4_VAL K_INT_MAP_I2 36 37 /* 38 * The general purpose timer ticks at 1MHz independent if 39 * the rest of the system 40 */ 41 static void sibyte_set_mode(enum clock_event_mode mode, 42 struct clock_event_device *evt) 43 { 44 unsigned int cpu = smp_processor_id(); 45 void __iomem *cfg, *init; 46 47 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)); 48 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)); 49 50 switch (mode) { 51 case CLOCK_EVT_MODE_PERIODIC: 52 __raw_writeq(0, cfg); 53 __raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, init); 54 __raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, 55 cfg); 56 break; 57 58 case CLOCK_EVT_MODE_ONESHOT: 59 /* Stop the timer until we actually program a shot */ 60 case CLOCK_EVT_MODE_SHUTDOWN: 61 __raw_writeq(0, cfg); 62 break; 63 64 case CLOCK_EVT_MODE_UNUSED: /* shuddup gcc */ 65 case CLOCK_EVT_MODE_RESUME: 66 ; 67 } 68 } 69 70 static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd) 71 { 72 unsigned int cpu = smp_processor_id(); 73 void __iomem *cfg, *init; 74 75 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)); 76 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)); 77 78 __raw_writeq(0, cfg); 79 __raw_writeq(delta - 1, init); 80 __raw_writeq(M_SCD_TIMER_ENABLE, cfg); 81 82 return 0; 83 } 84 85 static irqreturn_t sibyte_counter_handler(int irq, void *dev_id) 86 { 87 unsigned int cpu = smp_processor_id(); 88 struct clock_event_device *cd = dev_id; 89 void __iomem *cfg; 90 unsigned long tmode; 91 92 if (cd->mode == CLOCK_EVT_MODE_PERIODIC) 93 tmode = M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS; 94 else 95 tmode = 0; 96 97 /* ACK interrupt */ 98 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)); 99 ____raw_writeq(tmode, cfg); 100 101 cd->event_handler(cd); 102 103 return IRQ_HANDLED; 104 } 105 106 static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent); 107 static DEFINE_PER_CPU(struct irqaction, sibyte_hpt_irqaction); 108 static DEFINE_PER_CPU(char [18], sibyte_hpt_name); 109 110 void __cpuinit sb1250_clockevent_init(void) 111 { 112 unsigned int cpu = smp_processor_id(); 113 unsigned int irq = K_INT_TIMER_0 + cpu; 114 struct irqaction *action = &per_cpu(sibyte_hpt_irqaction, cpu); 115 struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu); 116 unsigned char *name = per_cpu(sibyte_hpt_name, cpu); 117 118 /* Only have 4 general purpose timers, and we use last one as hpt */ 119 BUG_ON(cpu > 2); 120 121 sprintf(name, "sb1250-counter-%d", cpu); 122 cd->name = name; 123 cd->features = CLOCK_EVT_FEAT_PERIODIC | 124 CLOCK_EVT_FEAT_ONESHOT; 125 clockevent_set_clock(cd, V_SCD_TIMER_FREQ); 126 cd->max_delta_ns = clockevent_delta2ns(0x7fffff, cd); 127 cd->min_delta_ns = clockevent_delta2ns(2, cd); 128 cd->rating = 200; 129 cd->irq = irq; 130 cd->cpumask = cpumask_of(cpu); 131 cd->set_next_event = sibyte_next_event; 132 cd->set_mode = sibyte_set_mode; 133 clockevents_register_device(cd); 134 135 sb1250_mask_irq(cpu, irq); 136 137 /* 138 * Map the timer interrupt to IP[4] of this cpu 139 */ 140 __raw_writeq(IMR_IP4_VAL, 141 IOADDR(A_IMR_REGISTER(cpu, R_IMR_INTERRUPT_MAP_BASE) + 142 (irq << 3))); 143 144 sb1250_unmask_irq(cpu, irq); 145 146 action->handler = sibyte_counter_handler; 147 action->flags = IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER; 148 action->name = name; 149 action->dev_id = cd; 150 151 irq_set_affinity(irq, cpumask_of(cpu)); 152 setup_irq(irq, action); 153 } 154