linux/drivers/clocksource/meson6_timer.c
Daniel Lezcano 1727339590 clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE
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>
2017-06-14 11:58:45 +02:00

179 lines
4.4 KiB
C

/*
* Amlogic Meson6 SoCs timer handling.
*
* Copyright (C) 2014 Carlo Caione <carlo@caione.org>
*
* Based on code from Amlogic, Inc
*
* 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.
*/
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqreturn.h>
#include <linux/sched_clock.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#define CED_ID 0
#define CSD_ID 4
#define TIMER_ISA_MUX 0
#define TIMER_ISA_VAL(t) (((t) + 1) << 2)
#define TIMER_INPUT_BIT(t) (2 * (t))
#define TIMER_ENABLE_BIT(t) (16 + (t))
#define TIMER_PERIODIC_BIT(t) (12 + (t))
#define TIMER_CED_INPUT_MASK (3UL << TIMER_INPUT_BIT(CED_ID))
#define TIMER_CSD_INPUT_MASK (7UL << TIMER_INPUT_BIT(CSD_ID))
#define TIMER_CED_UNIT_1US 0
#define TIMER_CSD_UNIT_1US 1
static void __iomem *timer_base;
static u64 notrace meson6_timer_sched_read(void)
{
return (u64)readl(timer_base + TIMER_ISA_VAL(CSD_ID));
}
static void meson6_clkevt_time_stop(unsigned char timer)
{
u32 val = readl(timer_base + TIMER_ISA_MUX);
writel(val & ~TIMER_ENABLE_BIT(timer), timer_base + TIMER_ISA_MUX);
}
static void meson6_clkevt_time_setup(unsigned char timer, unsigned long delay)
{
writel(delay, timer_base + TIMER_ISA_VAL(timer));
}
static void meson6_clkevt_time_start(unsigned char timer, bool periodic)
{
u32 val = readl(timer_base + TIMER_ISA_MUX);
if (periodic)
val |= TIMER_PERIODIC_BIT(timer);
else
val &= ~TIMER_PERIODIC_BIT(timer);
writel(val | TIMER_ENABLE_BIT(timer), timer_base + TIMER_ISA_MUX);
}
static int meson6_shutdown(struct clock_event_device *evt)
{
meson6_clkevt_time_stop(CED_ID);
return 0;
}
static int meson6_set_oneshot(struct clock_event_device *evt)
{
meson6_clkevt_time_stop(CED_ID);
meson6_clkevt_time_start(CED_ID, false);
return 0;
}
static int meson6_set_periodic(struct clock_event_device *evt)
{
meson6_clkevt_time_stop(CED_ID);
meson6_clkevt_time_setup(CED_ID, USEC_PER_SEC / HZ - 1);
meson6_clkevt_time_start(CED_ID, true);
return 0;
}
static int meson6_clkevt_next_event(unsigned long evt,
struct clock_event_device *unused)
{
meson6_clkevt_time_stop(CED_ID);
meson6_clkevt_time_setup(CED_ID, evt);
meson6_clkevt_time_start(CED_ID, false);
return 0;
}
static struct clock_event_device meson6_clockevent = {
.name = "meson6_tick",
.rating = 400,
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = meson6_shutdown,
.set_state_periodic = meson6_set_periodic,
.set_state_oneshot = meson6_set_oneshot,
.tick_resume = meson6_shutdown,
.set_next_event = meson6_clkevt_next_event,
};
static irqreturn_t meson6_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = (struct clock_event_device *)dev_id;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction meson6_timer_irq = {
.name = "meson6_timer",
.flags = IRQF_TIMER | IRQF_IRQPOLL,
.handler = meson6_timer_interrupt,
.dev_id = &meson6_clockevent,
};
static int __init meson6_timer_init(struct device_node *node)
{
u32 val;
int ret, irq;
timer_base = of_io_request_and_map(node, 0, "meson6-timer");
if (IS_ERR(timer_base)) {
pr_err("Can't map registers\n");
return -ENXIO;
}
irq = irq_of_parse_and_map(node, 0);
if (irq <= 0) {
pr_err("Can't parse IRQ\n");
return -EINVAL;
}
/* Set 1us for timer E */
val = readl(timer_base + TIMER_ISA_MUX);
val &= ~TIMER_CSD_INPUT_MASK;
val |= TIMER_CSD_UNIT_1US << TIMER_INPUT_BIT(CSD_ID);
writel(val, timer_base + TIMER_ISA_MUX);
sched_clock_register(meson6_timer_sched_read, 32, USEC_PER_SEC);
clocksource_mmio_init(timer_base + TIMER_ISA_VAL(CSD_ID), node->name,
1000 * 1000, 300, 32, clocksource_mmio_readl_up);
/* Timer A base 1us */
val &= ~TIMER_CED_INPUT_MASK;
val |= TIMER_CED_UNIT_1US << TIMER_INPUT_BIT(CED_ID);
writel(val, timer_base + TIMER_ISA_MUX);
/* Stop the timer A */
meson6_clkevt_time_stop(CED_ID);
ret = setup_irq(irq, &meson6_timer_irq);
if (ret) {
pr_warn("failed to setup irq %d\n", irq);
return ret;
}
meson6_clockevent.cpumask = cpu_possible_mask;
meson6_clockevent.irq = irq;
clockevents_config_and_register(&meson6_clockevent, USEC_PER_SEC,
1, 0xfffe);
return 0;
}
TIMER_OF_DECLARE(meson6, "amlogic,meson6-timer",
meson6_timer_init);