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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Altera Corporation
* Copyright (c) 2011 Picochip Ltd., Jamie Iles
*
* Modified from mach-picoxcell/time.c
*/
#include <linux/delay.h>
#include <linux/dw_apb_timer.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/clk.h>
#include <linux/reset.h>
#include <linux/sched_clock.h>
static int __init timer_get_base_and_rate(struct device_node *np,
void __iomem **base, u32 *rate)
{
struct clk *timer_clk;
struct clk *pclk;
struct reset_control *rstc;
int ret;
*base = of_iomap(np, 0);
if (!*base)
panic("Unable to map regs for %pOFn", np);
/*
* Reset the timer if the reset control is available, wiping
* out the state the firmware may have left it
*/
rstc = of_reset_control_get(np, NULL);
if (!IS_ERR(rstc)) {
reset_control_assert(rstc);
reset_control_deassert(rstc);
}
/*
* Not all implementations use a periphal clock, so don't panic
* if it's not present
*/
pclk = of_clk_get_by_name(np, "pclk");
if (!IS_ERR(pclk))
if (clk_prepare_enable(pclk))
pr_warn("pclk for %pOFn is present, but could not be activated\n",
np);
if (!of_property_read_u32(np, "clock-freq", rate) &&
!of_property_read_u32(np, "clock-frequency", rate))
return 0;
timer_clk = of_clk_get_by_name(np, "timer");
if (IS_ERR(timer_clk))
return PTR_ERR(timer_clk);
ret = clk_prepare_enable(timer_clk);
if (ret)
return ret;
*rate = clk_get_rate(timer_clk);
if (!(*rate))
return -EINVAL;
return 0;
}
static int __init add_clockevent(struct device_node *event_timer)
{
void __iomem *iobase;
struct dw_apb_clock_event_device *ced;
u32 irq, rate;
int ret = 0;
irq = irq_of_parse_and_map(event_timer, 0);
if (irq == 0)
panic("No IRQ for clock event timer");
ret = timer_get_base_and_rate(event_timer, &iobase, &rate);
if (ret)
return ret;
ced = dw_apb_clockevent_init(-1, event_timer->name, 300, iobase, irq,
rate);
if (!ced)
return -EINVAL;
dw_apb_clockevent_register(ced);
return 0;
}
static void __iomem *sched_io_base;
static u32 sched_rate;
static int __init add_clocksource(struct device_node *source_timer)
{
void __iomem *iobase;
struct dw_apb_clocksource *cs;
u32 rate;
int ret;
ret = timer_get_base_and_rate(source_timer, &iobase, &rate);
if (ret)
return ret;
cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate);
if (!cs)
return -EINVAL;
dw_apb_clocksource_start(cs);
dw_apb_clocksource_register(cs);
/*
* Fallback to use the clocksource as sched_clock if no separate
* timer is found. sched_io_base then points to the current_value
* register of the clocksource timer.
*/
sched_io_base = iobase + 0x04;
sched_rate = rate;
return 0;
}
static u64 notrace read_sched_clock(void)
{
return ~readl_relaxed(sched_io_base);
}
static const struct of_device_id sptimer_ids[] __initconst = {
{ .compatible = "picochip,pc3x2-rtc" },
{ /* Sentinel */ },
};
static void __init init_sched_clock(void)
{
struct device_node *sched_timer;
sched_timer = of_find_matching_node(NULL, sptimer_ids);
if (sched_timer) {
timer_get_base_and_rate(sched_timer, &sched_io_base,
&sched_rate);
of_node_put(sched_timer);
}
sched_clock_register(read_sched_clock, 32, sched_rate);
}
#ifdef CONFIG_ARM
static unsigned long dw_apb_delay_timer_read(void)
{
return ~readl_relaxed(sched_io_base);
}
static struct delay_timer dw_apb_delay_timer = {
.read_current_timer = dw_apb_delay_timer_read,
};
#endif
static int num_called;
static int __init dw_apb_timer_init(struct device_node *timer)
{
int ret = 0;
switch (num_called) {
case 1:
pr_debug("%s: found clocksource timer\n", __func__);
ret = add_clocksource(timer);
if (ret)
return ret;
init_sched_clock();
#ifdef CONFIG_ARM
dw_apb_delay_timer.freq = sched_rate;
register_current_timer_delay(&dw_apb_delay_timer);
#endif
break;
default:
pr_debug("%s: found clockevent timer\n", __func__);
ret = add_clockevent(timer);
if (ret)
return ret;
break;
}
num_called++;
return 0;
}
TIMER_OF_DECLARE(pc3x2_timer, "picochip,pc3x2-timer", dw_apb_timer_init);
TIMER_OF_DECLARE(apb_timer_osc, "snps,dw-apb-timer-osc", dw_apb_timer_init);
TIMER_OF_DECLARE(apb_timer_sp, "snps,dw-apb-timer-sp", dw_apb_timer_init);
TIMER_OF_DECLARE(apb_timer, "snps,dw-apb-timer", dw_apb_timer_init);
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