1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1992 Linus Torvalds 7 * Copyright (C) 1994 - 2001, 2003, 07 Ralf Baechle 8 */ 9 #include <linux/clockchips.h> 10 #include <linux/i8253.h> 11 #include <linux/init.h> 12 #include <linux/interrupt.h> 13 #include <linux/kernel.h> 14 #include <linux/smp.h> 15 #include <linux/spinlock.h> 16 #include <linux/irq.h> 17 18 #include <asm/irq_cpu.h> 19 #include <asm/i8259.h> 20 #include <asm/io.h> 21 #include <asm/jazz.h> 22 #include <asm/pgtable.h> 23 #include <asm/tlbmisc.h> 24 25 static DEFINE_RAW_SPINLOCK(r4030_lock); 26 27 static void enable_r4030_irq(struct irq_data *d) 28 { 29 unsigned int mask = 1 << (d->irq - JAZZ_IRQ_START); 30 unsigned long flags; 31 32 raw_spin_lock_irqsave(&r4030_lock, flags); 33 mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE); 34 r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask); 35 raw_spin_unlock_irqrestore(&r4030_lock, flags); 36 } 37 38 void disable_r4030_irq(struct irq_data *d) 39 { 40 unsigned int mask = ~(1 << (d->irq - JAZZ_IRQ_START)); 41 unsigned long flags; 42 43 raw_spin_lock_irqsave(&r4030_lock, flags); 44 mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE); 45 r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask); 46 raw_spin_unlock_irqrestore(&r4030_lock, flags); 47 } 48 49 static struct irq_chip r4030_irq_type = { 50 .name = "R4030", 51 .irq_mask = disable_r4030_irq, 52 .irq_unmask = enable_r4030_irq, 53 }; 54 55 void __init init_r4030_ints(void) 56 { 57 int i; 58 59 for (i = JAZZ_IRQ_START; i <= JAZZ_IRQ_END; i++) 60 irq_set_chip_and_handler(i, &r4030_irq_type, handle_level_irq); 61 62 r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0); 63 r4030_read_reg16(JAZZ_IO_IRQ_SOURCE); /* clear pending IRQs */ 64 r4030_read_reg32(JAZZ_R4030_INVAL_ADDR); /* clear error bits */ 65 } 66 67 /* 68 * On systems with i8259-style interrupt controllers we assume for 69 * driver compatibility reasons interrupts 0 - 15 to be the i8259 70 * interrupts even if the hardware uses a different interrupt numbering. 71 */ 72 void __init arch_init_irq(void) 73 { 74 /* 75 * this is a hack to get back the still needed wired mapping 76 * killed by init_mm() 77 */ 78 79 /* Map 0xe0000000 -> 0x0:800005C0, 0xe0010000 -> 0x1:30000580 */ 80 add_wired_entry(0x02000017, 0x03c00017, 0xe0000000, PM_64K); 81 /* Map 0xe2000000 -> 0x0:900005C0, 0xe3010000 -> 0x0:910005C0 */ 82 add_wired_entry(0x02400017, 0x02440017, 0xe2000000, PM_16M); 83 /* Map 0xe4000000 -> 0x0:600005C0, 0xe4100000 -> 400005C0 */ 84 add_wired_entry(0x01800017, 0x01000017, 0xe4000000, PM_4M); 85 86 init_i8259_irqs(); /* Integrated i8259 */ 87 mips_cpu_irq_init(); 88 init_r4030_ints(); 89 90 change_c0_status(ST0_IM, IE_IRQ2 | IE_IRQ1); 91 } 92 93 asmlinkage void plat_irq_dispatch(void) 94 { 95 unsigned int pending = read_c0_cause() & read_c0_status(); 96 unsigned int irq; 97 98 if (pending & IE_IRQ4) { 99 r4030_read_reg32(JAZZ_TIMER_REGISTER); 100 do_IRQ(JAZZ_TIMER_IRQ); 101 } else if (pending & IE_IRQ2) { 102 irq = *(volatile u8 *)JAZZ_EISA_IRQ_ACK; 103 do_IRQ(irq); 104 } else if (pending & IE_IRQ1) { 105 irq = *(volatile u8 *)JAZZ_IO_IRQ_SOURCE >> 2; 106 if (likely(irq > 0)) 107 do_IRQ(irq + JAZZ_IRQ_START - 1); 108 else 109 panic("Unimplemented loc_no_irq handler"); 110 } 111 } 112 113 struct clock_event_device r4030_clockevent = { 114 .name = "r4030", 115 .features = CLOCK_EVT_FEAT_PERIODIC, 116 .rating = 300, 117 .irq = JAZZ_TIMER_IRQ, 118 }; 119 120 static irqreturn_t r4030_timer_interrupt(int irq, void *dev_id) 121 { 122 struct clock_event_device *cd = dev_id; 123 124 cd->event_handler(cd); 125 return IRQ_HANDLED; 126 } 127 128 static struct irqaction r4030_timer_irqaction = { 129 .handler = r4030_timer_interrupt, 130 .flags = IRQF_TIMER, 131 .name = "R4030 timer", 132 }; 133 134 void __init plat_time_init(void) 135 { 136 struct clock_event_device *cd = &r4030_clockevent; 137 struct irqaction *action = &r4030_timer_irqaction; 138 unsigned int cpu = smp_processor_id(); 139 140 BUG_ON(HZ != 100); 141 142 cd->cpumask = cpumask_of(cpu); 143 clockevents_register_device(cd); 144 action->dev_id = cd; 145 setup_irq(JAZZ_TIMER_IRQ, action); 146 147 /* 148 * Set clock to 100Hz. 149 * 150 * The R4030 timer receives an input clock of 1kHz which is divieded by 151 * a programmable 4-bit divider. This makes it fairly inflexible. 152 */ 153 r4030_write_reg32(JAZZ_TIMER_INTERVAL, 9); 154 setup_pit_timer(); 155 } 156