summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/cevt-sb1250.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--arch/mips/kernel/cevt-sb1250.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/mips/kernel/cevt-sb1250.c b/arch/mips/kernel/cevt-sb1250.c
new file mode 100644
index 000000000..0451273fa
--- /dev/null
+++ b/arch/mips/kernel/cevt-sb1250.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2000, 2001 Broadcom Corporation
+ */
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/percpu.h>
+#include <linux/smp.h>
+
+#include <asm/addrspace.h>
+#include <asm/io.h>
+#include <asm/time.h>
+
+#include <asm/sibyte/sb1250.h>
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_int.h>
+#include <asm/sibyte/sb1250_scd.h>
+
+#define IMR_IP2_VAL K_INT_MAP_I0
+#define IMR_IP3_VAL K_INT_MAP_I1
+#define IMR_IP4_VAL K_INT_MAP_I2
+
+/*
+ * The general purpose timer ticks at 1MHz independent if
+ * the rest of the system
+ */
+
+static int sibyte_shutdown(struct clock_event_device *evt)
+{
+ void __iomem *cfg;
+
+ cfg = IOADDR(A_SCD_TIMER_REGISTER(smp_processor_id(), R_SCD_TIMER_CFG));
+
+ /* Stop the timer until we actually program a shot */
+ __raw_writeq(0, cfg);
+
+ return 0;
+}
+
+static int sibyte_set_periodic(struct clock_event_device *evt)
+{
+ unsigned int cpu = smp_processor_id();
+ void __iomem *cfg, *init;
+
+ cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
+ init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
+
+ __raw_writeq(0, cfg);
+ __raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, init);
+ __raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, cfg);
+
+ return 0;
+}
+
+static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd)
+{
+ unsigned int cpu = smp_processor_id();
+ void __iomem *cfg, *init;
+
+ cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
+ init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
+
+ __raw_writeq(0, cfg);
+ __raw_writeq(delta - 1, init);
+ __raw_writeq(M_SCD_TIMER_ENABLE, cfg);
+
+ return 0;
+}
+
+static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)
+{
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *cd = dev_id;
+ void __iomem *cfg;
+ unsigned long tmode;
+
+ if (clockevent_state_periodic(cd))
+ tmode = M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS;
+ else
+ tmode = 0;
+
+ /* ACK interrupt */
+ cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
+ ____raw_writeq(tmode, cfg);
+
+ cd->event_handler(cd);
+
+ return IRQ_HANDLED;
+}
+
+static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);
+static DEFINE_PER_CPU(char [18], sibyte_hpt_name);
+
+void sb1250_clockevent_init(void)
+{
+ unsigned int cpu = smp_processor_id();
+ unsigned int irq = K_INT_TIMER_0 + cpu;
+ struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);
+ unsigned char *name = per_cpu(sibyte_hpt_name, cpu);
+ unsigned long flags = IRQF_PERCPU | IRQF_TIMER;
+
+ /* Only have 4 general purpose timers, and we use last one as hpt */
+ BUG_ON(cpu > 2);
+
+ sprintf(name, "sb1250-counter-%d", cpu);
+ cd->name = name;
+ cd->features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT;
+ clockevent_set_clock(cd, V_SCD_TIMER_FREQ);
+ cd->max_delta_ns = clockevent_delta2ns(0x7fffff, cd);
+ cd->max_delta_ticks = 0x7fffff;
+ cd->min_delta_ns = clockevent_delta2ns(2, cd);
+ cd->min_delta_ticks = 2;
+ cd->rating = 200;
+ cd->irq = irq;
+ cd->cpumask = cpumask_of(cpu);
+ cd->set_next_event = sibyte_next_event;
+ cd->set_state_shutdown = sibyte_shutdown;
+ cd->set_state_periodic = sibyte_set_periodic;
+ cd->set_state_oneshot = sibyte_shutdown;
+ clockevents_register_device(cd);
+
+ sb1250_mask_irq(cpu, irq);
+
+ /*
+ * Map the timer interrupt to IP[4] of this cpu
+ */
+ __raw_writeq(IMR_IP4_VAL,
+ IOADDR(A_IMR_REGISTER(cpu, R_IMR_INTERRUPT_MAP_BASE) +
+ (irq << 3)));
+
+ sb1250_unmask_irq(cpu, irq);
+
+ irq_set_affinity(irq, cpumask_of(cpu));
+ if (request_irq(irq, sibyte_counter_handler, flags, name, cd))
+ pr_err("Failed to request irq %d (%s)\n", irq, name);
+}