effbfdd7ba
In cases where we have multiple nodes of the same type, we may need the node pointer to know which node was matched. Passing the node pointer also keeps the init function from having to match the node a 2nd time. Update bcm2835, vt8500, and tegra20 init functions for the new function prototype. Further tegra20 clean-ups are in follow-up commit. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Stephen Warren <swarren@nvidia.com> Tested-by: Stephen Warren <swarren@nvidia.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Tony Prisk <linux@prisktech.co.nz> Tested-by: Michal Simek <michal.simek@xilinx.com>
149 lines
4 KiB
C
149 lines
4 KiB
C
/*
|
|
* Copyright 2012 Simon Arlott
|
|
*
|
|
* 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/bitops.h>
|
|
#include <linux/clockchips.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/irqreturn.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_irq.h>
|
|
#include <linux/of_platform.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
|
|
#include <asm/sched_clock.h>
|
|
#include <asm/irq.h>
|
|
|
|
#define REG_CONTROL 0x00
|
|
#define REG_COUNTER_LO 0x04
|
|
#define REG_COUNTER_HI 0x08
|
|
#define REG_COMPARE(n) (0x0c + (n) * 4)
|
|
#define MAX_TIMER 3
|
|
#define DEFAULT_TIMER 3
|
|
|
|
struct bcm2835_timer {
|
|
void __iomem *control;
|
|
void __iomem *compare;
|
|
int match_mask;
|
|
struct clock_event_device evt;
|
|
struct irqaction act;
|
|
};
|
|
|
|
static void __iomem *system_clock __read_mostly;
|
|
|
|
static u32 notrace bcm2835_sched_read(void)
|
|
{
|
|
return readl_relaxed(system_clock);
|
|
}
|
|
|
|
static void bcm2835_time_set_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *evt_dev)
|
|
{
|
|
switch (mode) {
|
|
case CLOCK_EVT_MODE_ONESHOT:
|
|
case CLOCK_EVT_MODE_UNUSED:
|
|
case CLOCK_EVT_MODE_SHUTDOWN:
|
|
case CLOCK_EVT_MODE_RESUME:
|
|
break;
|
|
default:
|
|
WARN(1, "%s: unhandled event mode %d\n", __func__, mode);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int bcm2835_time_set_next_event(unsigned long event,
|
|
struct clock_event_device *evt_dev)
|
|
{
|
|
struct bcm2835_timer *timer = container_of(evt_dev,
|
|
struct bcm2835_timer, evt);
|
|
writel_relaxed(readl_relaxed(system_clock) + event,
|
|
timer->compare);
|
|
return 0;
|
|
}
|
|
|
|
static irqreturn_t bcm2835_time_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct bcm2835_timer *timer = dev_id;
|
|
void (*event_handler)(struct clock_event_device *);
|
|
if (readl_relaxed(timer->control) & timer->match_mask) {
|
|
writel_relaxed(timer->match_mask, timer->control);
|
|
|
|
event_handler = ACCESS_ONCE(timer->evt.event_handler);
|
|
if (event_handler)
|
|
event_handler(&timer->evt);
|
|
return IRQ_HANDLED;
|
|
} else {
|
|
return IRQ_NONE;
|
|
}
|
|
}
|
|
|
|
static void __init bcm2835_timer_init(struct device_node *node)
|
|
{
|
|
void __iomem *base;
|
|
u32 freq;
|
|
int irq;
|
|
struct bcm2835_timer *timer;
|
|
|
|
base = of_iomap(node, 0);
|
|
if (!base)
|
|
panic("Can't remap registers");
|
|
|
|
if (of_property_read_u32(node, "clock-frequency", &freq))
|
|
panic("Can't read clock-frequency");
|
|
|
|
system_clock = base + REG_COUNTER_LO;
|
|
setup_sched_clock(bcm2835_sched_read, 32, freq);
|
|
|
|
clocksource_mmio_init(base + REG_COUNTER_LO, node->name,
|
|
freq, 300, 32, clocksource_mmio_readl_up);
|
|
|
|
irq = irq_of_parse_and_map(node, DEFAULT_TIMER);
|
|
if (irq <= 0)
|
|
panic("Can't parse IRQ");
|
|
|
|
timer = kzalloc(sizeof(*timer), GFP_KERNEL);
|
|
if (!timer)
|
|
panic("Can't allocate timer struct\n");
|
|
|
|
timer->control = base + REG_CONTROL;
|
|
timer->compare = base + REG_COMPARE(DEFAULT_TIMER);
|
|
timer->match_mask = BIT(DEFAULT_TIMER);
|
|
timer->evt.name = node->name;
|
|
timer->evt.rating = 300;
|
|
timer->evt.features = CLOCK_EVT_FEAT_ONESHOT;
|
|
timer->evt.set_mode = bcm2835_time_set_mode;
|
|
timer->evt.set_next_event = bcm2835_time_set_next_event;
|
|
timer->evt.cpumask = cpumask_of(0);
|
|
timer->act.name = node->name;
|
|
timer->act.flags = IRQF_TIMER | IRQF_SHARED;
|
|
timer->act.dev_id = timer;
|
|
timer->act.handler = bcm2835_time_interrupt;
|
|
|
|
if (setup_irq(irq, &timer->act))
|
|
panic("Can't set up timer IRQ\n");
|
|
|
|
clockevents_config_and_register(&timer->evt, freq, 0xf, 0xffffffff);
|
|
|
|
pr_info("bcm2835: system timer (irq = %d)\n", irq);
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(bcm2835, "brcm,bcm2835-system-timer",
|
|
bcm2835_timer_init);
|