1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2000, 2001 Broadcom Corporation
4 */
5#include <linux/clockchips.h>
6#include <linux/interrupt.h>
7#include <linux/irq.h>
8#include <linux/percpu.h>
9#include <linux/smp.h>
10
11#include <asm/addrspace.h>
12#include <asm/io.h>
13#include <asm/time.h>
14
15#include <asm/sibyte/sb1250.h>
16#include <asm/sibyte/sb1250_regs.h>
17#include <asm/sibyte/sb1250_int.h>
18#include <asm/sibyte/sb1250_scd.h>
19
20#define IMR_IP2_VAL K_INT_MAP_I0
21#define IMR_IP3_VAL K_INT_MAP_I1
22#define IMR_IP4_VAL K_INT_MAP_I2
23
24/*
25 * The general purpose timer ticks at 1MHz independent if
26 * the rest of the system
27 */
28
29static int sibyte_shutdown(struct clock_event_device *evt)
30{
31 void __iomem *cfg;
32
33 cfg = IOADDR(A_SCD_TIMER_REGISTER(smp_processor_id(), R_SCD_TIMER_CFG));
34
35 /* Stop the timer until we actually program a shot */
36 __raw_writeq(val: 0, addr: cfg);
37
38 return 0;
39}
40
41static int sibyte_set_periodic(struct clock_event_device *evt)
42{
43 unsigned int cpu = smp_processor_id();
44 void __iomem *cfg, *init;
45
46 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
47 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
48
49 __raw_writeq(val: 0, addr: cfg);
50 __raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, init);
51 __raw_writeq(val: M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, addr: cfg);
52
53 return 0;
54}
55
56static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd)
57{
58 unsigned int cpu = smp_processor_id();
59 void __iomem *cfg, *init;
60
61 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
62 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
63
64 __raw_writeq(val: 0, addr: cfg);
65 __raw_writeq(val: delta - 1, addr: init);
66 __raw_writeq(val: M_SCD_TIMER_ENABLE, addr: cfg);
67
68 return 0;
69}
70
71static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)
72{
73 unsigned int cpu = smp_processor_id();
74 struct clock_event_device *cd = dev_id;
75 void __iomem *cfg;
76 unsigned long tmode;
77
78 if (clockevent_state_periodic(dev: cd))
79 tmode = M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS;
80 else
81 tmode = 0;
82
83 /* ACK interrupt */
84 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
85 ____raw_writeq(tmode, cfg);
86
87 cd->event_handler(cd);
88
89 return IRQ_HANDLED;
90}
91
92static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);
93static DEFINE_PER_CPU(char [18], sibyte_hpt_name);
94
95void sb1250_clockevent_init(void)
96{
97 unsigned int cpu = smp_processor_id();
98 unsigned int irq = K_INT_TIMER_0 + cpu;
99 struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);
100 unsigned char *name = per_cpu(sibyte_hpt_name, cpu);
101 unsigned long flags = IRQF_PERCPU | IRQF_TIMER;
102
103 /* Only have 4 general purpose timers, and we use last one as hpt */
104 BUG_ON(cpu > 2);
105
106 sprintf(buf: name, fmt: "sb1250-counter-%d", cpu);
107 cd->name = name;
108 cd->features = CLOCK_EVT_FEAT_PERIODIC |
109 CLOCK_EVT_FEAT_ONESHOT;
110 clockevent_set_clock(cd, V_SCD_TIMER_FREQ);
111 cd->max_delta_ns = clockevent_delta2ns(latch: 0x7fffff, evt: cd);
112 cd->max_delta_ticks = 0x7fffff;
113 cd->min_delta_ns = clockevent_delta2ns(latch: 2, evt: cd);
114 cd->min_delta_ticks = 2;
115 cd->rating = 200;
116 cd->irq = irq;
117 cd->cpumask = cpumask_of(cpu);
118 cd->set_next_event = sibyte_next_event;
119 cd->set_state_shutdown = sibyte_shutdown;
120 cd->set_state_periodic = sibyte_set_periodic;
121 cd->set_state_oneshot = sibyte_shutdown;
122 clockevents_register_device(dev: cd);
123
124 sb1250_mask_irq(cpu, irq);
125
126 /*
127 * Map the timer interrupt to IP[4] of this cpu
128 */
129 __raw_writeq(IMR_IP4_VAL,
130 addr: IOADDR(A_IMR_REGISTER(cpu, R_IMR_INTERRUPT_MAP_BASE) +
131 (irq << 3)));
132
133 sb1250_unmask_irq(cpu, irq);
134
135 irq_set_affinity(irq, cpumask_of(cpu));
136 if (request_irq(irq, handler: sibyte_counter_handler, flags, name, dev: cd))
137 pr_err("Failed to request irq %d (%s)\n", irq, name);
138}
139

source code of linux/arch/mips/kernel/cevt-sb1250.c