1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2000,2001,2004 Broadcom Corporation
4 */
5 #include <linux/clockchips.h>
6 #include <linux/interrupt.h>
7 #include <linux/percpu.h>
8 #include <linux/smp.h>
9 #include <linux/irq.h>
10
11 #include <asm/addrspace.h>
12 #include <asm/io.h>
13 #include <asm/time.h>
14
15 #include <asm/sibyte/bcm1480_regs.h>
16 #include <asm/sibyte/sb1250_regs.h>
17 #include <asm/sibyte/bcm1480_int.h>
18 #include <asm/sibyte/bcm1480_scd.h>
19
20 #include <asm/sibyte/sb1250.h>
21
22 #define IMR_IP2_VAL K_BCM1480_INT_MAP_I0
23 #define IMR_IP3_VAL K_BCM1480_INT_MAP_I1
24 #define IMR_IP4_VAL K_BCM1480_INT_MAP_I2
25
26 /*
27 * The general purpose timer ticks at 1MHz independent if
28 * the rest of the system
29 */
30
31 static int sibyte_set_periodic(struct clock_event_device *evt)
32 {
33 unsigned int cpu = smp_processor_id();
34 void __iomem *cfg, *init;
35
36 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
37 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
38
39 __raw_writeq(0, cfg);
40 __raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, init);
41 __raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, cfg);
42 return 0;
43 }
44
45 static int sibyte_shutdown(struct clock_event_device *evt)
46 {
47 unsigned int cpu = smp_processor_id();
48 void __iomem *cfg;
49
50 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
51
52 /* Stop the timer until we actually program a shot */
53 __raw_writeq(0, cfg);
54 return 0;
55 }
56
57 static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd)
58 {
59 unsigned int cpu = smp_processor_id();
60 void __iomem *cfg, *init;
61
62 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
63 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
64
65 __raw_writeq(0, cfg);
66 __raw_writeq(delta - 1, init);
67 __raw_writeq(M_SCD_TIMER_ENABLE, cfg);
68
69 return 0;
70 }
71
72 static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)
73 {
74 unsigned int cpu = smp_processor_id();
75 struct clock_event_device *cd = dev_id;
76 void __iomem *cfg;
77 unsigned long tmode;
78
79 if (clockevent_state_periodic(cd))
80 tmode = M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS;
81 else
82 tmode = 0;
83
84 /* ACK interrupt */
85 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
86 ____raw_writeq(tmode, cfg);
87
88 cd->event_handler(cd);
89
90 return IRQ_HANDLED;
91 }
92
93 static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);
94 static DEFINE_PER_CPU(char [18], sibyte_hpt_name);
95
96 void sb1480_clockevent_init(void)
97 {
98 unsigned int cpu = smp_processor_id();
99 unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
100 struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);
101 unsigned char *name = per_cpu(sibyte_hpt_name, cpu);
102 unsigned long flags = IRQF_PERCPU | IRQF_TIMER;
103
104 BUG_ON(cpu > 3); /* Only have 4 general purpose timers */
105
106 sprintf(name, "bcm1480-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(0x7fffff, cd);
112 cd->max_delta_ticks = 0x7fffff;
113 cd->min_delta_ns = clockevent_delta2ns(2, 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(cd);
123
124 bcm1480_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 IOADDR(A_BCM1480_IMR_REGISTER(cpu,
131 R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (irq << 3)));
132
133 bcm1480_unmask_irq(cpu, irq);
134
135 irq_set_affinity(irq, cpumask_of(cpu));
136 if (request_irq(irq, sibyte_counter_handler, flags, name, cd))
137 pr_err("Failed to request irq %d (%s)\n", irq, name);
138 }
139
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