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 42 static int sibyte_shutdown(struct clock_event_device *evt) 43 { 44 void __iomem *cfg; 45 46 cfg = IOADDR(A_SCD_TIMER_REGISTER(smp_processor_id(), R_SCD_TIMER_CFG)); 47 48 /* Stop the timer until we actually program a shot */ 49 __raw_writeq(0, cfg); 50 51 return 0; 52 } 53 54 static int sibyte_set_periodic(struct clock_event_device *evt) 55 { 56 unsigned int cpu = smp_processor_id(); 57 void __iomem *cfg, *init; 58 59 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)); 60 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)); 61 62 __raw_writeq(0, cfg); 63 __raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, init); 64 __raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, cfg); 65 66 return 0; 67 } 68 69 static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd) 70 { 71 unsigned int cpu = smp_processor_id(); 72 void __iomem *cfg, *init; 73 74 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)); 75 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)); 76 77 __raw_writeq(0, cfg); 78 __raw_writeq(delta - 1, init); 79 __raw_writeq(M_SCD_TIMER_ENABLE, cfg); 80 81 return 0; 82 } 83 84 static irqreturn_t sibyte_counter_handler(int irq, void *dev_id) 85 { 86 unsigned int cpu = smp_processor_id(); 87 struct clock_event_device *cd = dev_id; 88 void __iomem *cfg; 89 unsigned long tmode; 90 91 if (clockevent_state_periodic(cd)) 92 tmode = M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS; 93 else 94 tmode = 0; 95 96 /* ACK interrupt */ 97 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)); 98 ____raw_writeq(tmode, cfg); 99 100 cd->event_handler(cd); 101 102 return IRQ_HANDLED; 103 } 104 105 static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent); 106 static DEFINE_PER_CPU(struct irqaction, sibyte_hpt_irqaction); 107 static DEFINE_PER_CPU(char [18], sibyte_hpt_name); 108 109 void sb1250_clockevent_init(void) 110 { 111 unsigned int cpu = smp_processor_id(); 112 unsigned int irq = K_INT_TIMER_0 + cpu; 113 struct irqaction *action = &per_cpu(sibyte_hpt_irqaction, cpu); 114 struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu); 115 unsigned char *name = per_cpu(sibyte_hpt_name, cpu); 116 117 /* Only have 4 general purpose timers, and we use last one as hpt */ 118 BUG_ON(cpu > 2); 119 120 sprintf(name, "sb1250-counter-%d", cpu); 121 cd->name = name; 122 cd->features = CLOCK_EVT_FEAT_PERIODIC | 123 CLOCK_EVT_FEAT_ONESHOT; 124 clockevent_set_clock(cd, V_SCD_TIMER_FREQ); 125 cd->max_delta_ns = clockevent_delta2ns(0x7fffff, cd); 126 cd->max_delta_ticks = 0x7fffff; 127 cd->min_delta_ns = clockevent_delta2ns(2, cd); 128 cd->min_delta_ticks = 2; 129 cd->rating = 200; 130 cd->irq = irq; 131 cd->cpumask = cpumask_of(cpu); 132 cd->set_next_event = sibyte_next_event; 133 cd->set_state_shutdown = sibyte_shutdown; 134 cd->set_state_periodic = sibyte_set_periodic; 135 cd->set_state_oneshot = sibyte_shutdown; 136 clockevents_register_device(cd); 137 138 sb1250_mask_irq(cpu, irq); 139 140 /* 141 * Map the timer interrupt to IP[4] of this cpu 142 */ 143 __raw_writeq(IMR_IP4_VAL, 144 IOADDR(A_IMR_REGISTER(cpu, R_IMR_INTERRUPT_MAP_BASE) + 145 (irq << 3))); 146 147 sb1250_unmask_irq(cpu, irq); 148 149 action->handler = sibyte_counter_handler; 150 action->flags = IRQF_PERCPU | IRQF_TIMER; 151 action->name = name; 152 action->dev_id = cd; 153 154 irq_set_affinity(irq, cpumask_of(cpu)); 155 setup_irq(irq, action); 156 } 157