mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
![Daniel Lezcano](/assets/img/avatar_default.png)
The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the clocksource at early stage. However, this macro is also used to initialize the clockevent if any, or the clockevent only. It was originally suggested to declare another macro to initialize a clockevent, so in order to separate the two entities even they belong to the same IP. This was not accepted because of the impact on the DT where splitting a clocksource/clockevent definition does not make sense as it is a Linux concept not a hardware description. On the other side, the clocksource has not interrupt declared while the clockevent has, so it is easy from the driver to know if the description is for a clockevent or a clocksource, IOW it could be implemented at the driver level. So instead of dealing with a named clocksource macro, let's use a more generic one: TIMER_OF_DECLARE. The patch has not functional changes. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Matthias Brugger <matthias.bgg@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
192 lines
4.7 KiB
C
192 lines
4.7 KiB
C
/*
|
|
* Marvell Orion SoC timer handling.
|
|
*
|
|
* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public
|
|
* License version 2. This program is licensed "as is" without any
|
|
* warranty of any kind, whether express or implied.
|
|
*
|
|
* Timer 0 is used as free-running clocksource, while timer 1 is
|
|
* used as clock_event_device.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/clockchips.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_irq.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/sched_clock.h>
|
|
|
|
#define TIMER_CTRL 0x00
|
|
#define TIMER0_EN BIT(0)
|
|
#define TIMER0_RELOAD_EN BIT(1)
|
|
#define TIMER1_EN BIT(2)
|
|
#define TIMER1_RELOAD_EN BIT(3)
|
|
#define TIMER0_RELOAD 0x10
|
|
#define TIMER0_VAL 0x14
|
|
#define TIMER1_RELOAD 0x18
|
|
#define TIMER1_VAL 0x1c
|
|
|
|
#define ORION_ONESHOT_MIN 1
|
|
#define ORION_ONESHOT_MAX 0xfffffffe
|
|
|
|
static void __iomem *timer_base;
|
|
|
|
static unsigned long notrace orion_read_timer(void)
|
|
{
|
|
return ~readl(timer_base + TIMER0_VAL);
|
|
}
|
|
|
|
static struct delay_timer orion_delay_timer = {
|
|
.read_current_timer = orion_read_timer,
|
|
};
|
|
|
|
static void orion_delay_timer_init(unsigned long rate)
|
|
{
|
|
orion_delay_timer.freq = rate;
|
|
register_current_timer_delay(&orion_delay_timer);
|
|
}
|
|
|
|
/*
|
|
* Free-running clocksource handling.
|
|
*/
|
|
static u64 notrace orion_read_sched_clock(void)
|
|
{
|
|
return ~readl(timer_base + TIMER0_VAL);
|
|
}
|
|
|
|
/*
|
|
* Clockevent handling.
|
|
*/
|
|
static u32 ticks_per_jiffy;
|
|
|
|
static int orion_clkevt_next_event(unsigned long delta,
|
|
struct clock_event_device *dev)
|
|
{
|
|
/* setup and enable one-shot timer */
|
|
writel(delta, timer_base + TIMER1_VAL);
|
|
atomic_io_modify(timer_base + TIMER_CTRL,
|
|
TIMER1_RELOAD_EN | TIMER1_EN, TIMER1_EN);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int orion_clkevt_shutdown(struct clock_event_device *dev)
|
|
{
|
|
/* disable timer */
|
|
atomic_io_modify(timer_base + TIMER_CTRL,
|
|
TIMER1_RELOAD_EN | TIMER1_EN, 0);
|
|
return 0;
|
|
}
|
|
|
|
static int orion_clkevt_set_periodic(struct clock_event_device *dev)
|
|
{
|
|
/* setup and enable periodic timer at 1/HZ intervals */
|
|
writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD);
|
|
writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL);
|
|
atomic_io_modify(timer_base + TIMER_CTRL,
|
|
TIMER1_RELOAD_EN | TIMER1_EN,
|
|
TIMER1_RELOAD_EN | TIMER1_EN);
|
|
return 0;
|
|
}
|
|
|
|
static struct clock_event_device orion_clkevt = {
|
|
.name = "orion_event",
|
|
.features = CLOCK_EVT_FEAT_ONESHOT |
|
|
CLOCK_EVT_FEAT_PERIODIC,
|
|
.shift = 32,
|
|
.rating = 300,
|
|
.set_next_event = orion_clkevt_next_event,
|
|
.set_state_shutdown = orion_clkevt_shutdown,
|
|
.set_state_periodic = orion_clkevt_set_periodic,
|
|
.set_state_oneshot = orion_clkevt_shutdown,
|
|
.tick_resume = orion_clkevt_shutdown,
|
|
};
|
|
|
|
static irqreturn_t orion_clkevt_irq_handler(int irq, void *dev_id)
|
|
{
|
|
orion_clkevt.event_handler(&orion_clkevt);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct irqaction orion_clkevt_irq = {
|
|
.name = "orion_event",
|
|
.flags = IRQF_TIMER,
|
|
.handler = orion_clkevt_irq_handler,
|
|
};
|
|
|
|
static int __init orion_timer_init(struct device_node *np)
|
|
{
|
|
unsigned long rate;
|
|
struct clk *clk;
|
|
int irq, ret;
|
|
|
|
/* timer registers are shared with watchdog timer */
|
|
timer_base = of_iomap(np, 0);
|
|
if (!timer_base) {
|
|
pr_err("%s: unable to map resource\n", np->name);
|
|
return -ENXIO;
|
|
}
|
|
|
|
clk = of_clk_get(np, 0);
|
|
if (IS_ERR(clk)) {
|
|
pr_err("%s: unable to get clk\n", np->name);
|
|
return PTR_ERR(clk);
|
|
}
|
|
|
|
ret = clk_prepare_enable(clk);
|
|
if (ret) {
|
|
pr_err("Failed to prepare clock\n");
|
|
return ret;
|
|
}
|
|
|
|
/* we are only interested in timer1 irq */
|
|
irq = irq_of_parse_and_map(np, 1);
|
|
if (irq <= 0) {
|
|
pr_err("%s: unable to parse timer1 irq\n", np->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
rate = clk_get_rate(clk);
|
|
|
|
/* setup timer0 as free-running clocksource */
|
|
writel(~0, timer_base + TIMER0_VAL);
|
|
writel(~0, timer_base + TIMER0_RELOAD);
|
|
atomic_io_modify(timer_base + TIMER_CTRL,
|
|
TIMER0_RELOAD_EN | TIMER0_EN,
|
|
TIMER0_RELOAD_EN | TIMER0_EN);
|
|
|
|
ret = clocksource_mmio_init(timer_base + TIMER0_VAL,
|
|
"orion_clocksource", rate, 300, 32,
|
|
clocksource_mmio_readl_down);
|
|
if (ret) {
|
|
pr_err("Failed to initialize mmio timer\n");
|
|
return ret;
|
|
}
|
|
|
|
sched_clock_register(orion_read_sched_clock, 32, rate);
|
|
|
|
/* setup timer1 as clockevent timer */
|
|
ret = setup_irq(irq, &orion_clkevt_irq);
|
|
if (ret) {
|
|
pr_err("%s: unable to setup irq\n", np->name);
|
|
return ret;
|
|
}
|
|
|
|
ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
|
|
orion_clkevt.cpumask = cpumask_of(0);
|
|
orion_clkevt.irq = irq;
|
|
clockevents_config_and_register(&orion_clkevt, rate,
|
|
ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
|
|
|
|
|
|
orion_delay_timer_init(rate);
|
|
|
|
return 0;
|
|
}
|
|
TIMER_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);
|