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
 31static 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
 45static 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
 57static 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
 72static 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
 93static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);
 94static DEFINE_PER_CPU(char [18], sibyte_hpt_name);
 95
 96void 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}