linux/arch/mips/kernel/cevt-bcm1480.c
Nicolai Stange e4db9253d6 MIPS: clockevent drivers: Set ->min_delta_ticks and ->max_delta_ticks
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.

Make the MIPS arch's clockevent drivers initialize these fields properly.

This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from these
drivers.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Keguang Zhang <keguang.zhang@gmail.com>
Cc: John Crispin <john@phrozen.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-04-14 13:11:16 -07:00

157 lines
4.4 KiB
C

/*
* Copyright (C) 2000,2001,2004 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/irq.h>
#include <asm/addrspace.h>
#include <asm/io.h>
#include <asm/time.h>
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/bcm1480_int.h>
#include <asm/sibyte/bcm1480_scd.h>
#include <asm/sibyte/sb1250.h>
#define IMR_IP2_VAL K_BCM1480_INT_MAP_I0
#define IMR_IP3_VAL K_BCM1480_INT_MAP_I1
#define IMR_IP4_VAL K_BCM1480_INT_MAP_I2
/*
* The general purpose timer ticks at 1MHz independent if
* the rest of the system
*/
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_shutdown(struct clock_event_device *evt)
{
unsigned int cpu = smp_processor_id();
void __iomem *cfg;
cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
/* Stop the timer until we actually program a shot */
__raw_writeq(0, 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(struct irqaction, sibyte_hpt_irqaction);
static DEFINE_PER_CPU(char [18], sibyte_hpt_name);
void sb1480_clockevent_init(void)
{
unsigned int cpu = smp_processor_id();
unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
struct irqaction *action = &per_cpu(sibyte_hpt_irqaction, cpu);
struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);
unsigned char *name = per_cpu(sibyte_hpt_name, cpu);
BUG_ON(cpu > 3); /* Only have 4 general purpose timers */
sprintf(name, "bcm1480-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);
bcm1480_mask_irq(cpu, irq);
/*
* Map the timer interrupt to IP[4] of this cpu
*/
__raw_writeq(IMR_IP4_VAL,
IOADDR(A_BCM1480_IMR_REGISTER(cpu,
R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (irq << 3)));
bcm1480_unmask_irq(cpu, irq);
action->handler = sibyte_counter_handler;
action->flags = IRQF_PERCPU | IRQF_TIMER;
action->name = name;
action->dev_id = cd;
irq_set_affinity(irq, cpumask_of(cpu));
setup_irq(irq, action);
}