linux/drivers/clocksource/timer-integrator-ap.c
Daniel Lezcano 177cf6e52b clocksources: Switch back to the clksrc table
All the clocksource drivers's init function are now converted to return
an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the
clksrc-of table.

Let's convert back the names:
 - CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE
 - clksrc-of-ret              => clksrc-of

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

For exynos_mct and samsung_pwm_timer:
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

For arch/arc:
Acked-by: Vineet Gupta <vgupta@synopsys.com>

For mediatek driver:
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>

For the Rockchip-part
Acked-by: Heiko Stuebner <heiko@sntech.de>

For STi :
Acked-by: Patrice Chotard <patrice.chotard@st.com>

For the mps2-timer.c and versatile.c changes:
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>

For the OXNAS part :
Acked-by: Neil Armstrong <narmstrong@baylibre.com>

For LPC32xx driver:
Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>

For Broadcom Kona timer change:
Acked-by: Ray Jui <ray.jui@broadcom.com>

For Sun4i and Sun5i:
Acked-by: Chen-Yu Tsai <wens@csie.org>

For Meson6:
Acked-by: Carlo Caione <carlo@caione.org>

For Keystone:
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>

For NPS:
Acked-by: Noam Camus <noamca@mellanox.com>

For bcm2835:
Acked-by: Eric Anholt <eric@anholt.net>
2016-06-28 10:19:35 +02:00

237 lines
5.8 KiB
C

/*
* Integrator/AP timer driver
* Copyright (C) 2000-2003 Deep Blue Solutions Ltd
* Copyright (c) 2014, Linaro Limited
*
* 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/clk.h>
#include <linux/clocksource.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/sched_clock.h>
#include "timer-sp.h"
static void __iomem * sched_clk_base;
static u64 notrace integrator_read_sched_clock(void)
{
return -readl(sched_clk_base + TIMER_VALUE);
}
static int integrator_clocksource_init(unsigned long inrate,
void __iomem *base)
{
u32 ctrl = TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC;
unsigned long rate = inrate;
int ret;
if (rate >= 1500000) {
rate /= 16;
ctrl |= TIMER_CTRL_DIV16;
}
writel(0xffff, base + TIMER_LOAD);
writel(ctrl, base + TIMER_CTRL);
ret = clocksource_mmio_init(base + TIMER_VALUE, "timer2",
rate, 200, 16, clocksource_mmio_readl_down);
if (ret)
return ret;
sched_clk_base = base;
sched_clock_register(integrator_read_sched_clock, 16, rate);
return 0;
}
static unsigned long timer_reload;
static void __iomem * clkevt_base;
/*
* IRQ handler for the timer
*/
static irqreturn_t integrator_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
/* clear the interrupt */
writel(1, clkevt_base + TIMER_INTCLR);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static int clkevt_shutdown(struct clock_event_device *evt)
{
u32 ctrl = readl(clkevt_base + TIMER_CTRL) & ~TIMER_CTRL_ENABLE;
/* Disable timer */
writel(ctrl, clkevt_base + TIMER_CTRL);
return 0;
}
static int clkevt_set_oneshot(struct clock_event_device *evt)
{
u32 ctrl = readl(clkevt_base + TIMER_CTRL) &
~(TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC);
/* Leave the timer disabled, .set_next_event will enable it */
writel(ctrl, clkevt_base + TIMER_CTRL);
return 0;
}
static int clkevt_set_periodic(struct clock_event_device *evt)
{
u32 ctrl = readl(clkevt_base + TIMER_CTRL) & ~TIMER_CTRL_ENABLE;
/* Disable timer */
writel(ctrl, clkevt_base + TIMER_CTRL);
/* Enable the timer and start the periodic tick */
writel(timer_reload, clkevt_base + TIMER_LOAD);
ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
writel(ctrl, clkevt_base + TIMER_CTRL);
return 0;
}
static int clkevt_set_next_event(unsigned long next, struct clock_event_device *evt)
{
unsigned long ctrl = readl(clkevt_base + TIMER_CTRL);
writel(ctrl & ~TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL);
writel(next, clkevt_base + TIMER_LOAD);
writel(ctrl | TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL);
return 0;
}
static struct clock_event_device integrator_clockevent = {
.name = "timer1",
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = clkevt_shutdown,
.set_state_periodic = clkevt_set_periodic,
.set_state_oneshot = clkevt_set_oneshot,
.tick_resume = clkevt_shutdown,
.set_next_event = clkevt_set_next_event,
.rating = 300,
};
static struct irqaction integrator_timer_irq = {
.name = "timer",
.flags = IRQF_TIMER | IRQF_IRQPOLL,
.handler = integrator_timer_interrupt,
.dev_id = &integrator_clockevent,
};
static int integrator_clockevent_init(unsigned long inrate,
void __iomem *base, int irq)
{
unsigned long rate = inrate;
unsigned int ctrl = 0;
int ret;
clkevt_base = base;
/* Calculate and program a divisor */
if (rate > 0x100000 * HZ) {
rate /= 256;
ctrl |= TIMER_CTRL_DIV256;
} else if (rate > 0x10000 * HZ) {
rate /= 16;
ctrl |= TIMER_CTRL_DIV16;
}
timer_reload = rate / HZ;
writel(ctrl, clkevt_base + TIMER_CTRL);
ret = setup_irq(irq, &integrator_timer_irq);
if (ret)
return ret;
clockevents_config_and_register(&integrator_clockevent,
rate,
1,
0xffffU);
return 0;
}
static int __init integrator_ap_timer_init_of(struct device_node *node)
{
const char *path;
void __iomem *base;
int err;
int irq;
struct clk *clk;
unsigned long rate;
struct device_node *pri_node;
struct device_node *sec_node;
base = of_io_request_and_map(node, 0, "integrator-timer");
if (IS_ERR(base))
return PTR_ERR(base);
clk = of_clk_get(node, 0);
if (IS_ERR(clk)) {
pr_err("No clock for %s\n", node->name);
return PTR_ERR(clk);
}
clk_prepare_enable(clk);
rate = clk_get_rate(clk);
writel(0, base + TIMER_CTRL);
err = of_property_read_string(of_aliases,
"arm,timer-primary", &path);
if (err) {
pr_warn("Failed to read property");
return err;
}
pri_node = of_find_node_by_path(path);
err = of_property_read_string(of_aliases,
"arm,timer-secondary", &path);
if (err) {
pr_warn("Failed to read property");
return err;
}
sec_node = of_find_node_by_path(path);
if (node == pri_node)
/* The primary timer lacks IRQ, use as clocksource */
return integrator_clocksource_init(rate, base);
if (node == sec_node) {
/* The secondary timer will drive the clock event */
irq = irq_of_parse_and_map(node, 0);
return integrator_clockevent_init(rate, base, irq);
}
pr_info("Timer @%p unused\n", base);
clk_disable_unprepare(clk);
return 0;
}
CLOCKSOURCE_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",
integrator_ap_timer_init_of);