157 lines
4.0 KiB
C
157 lines
4.0 KiB
C
/*
|
|
* Copyright (C) 2012 Altera Corporation
|
|
* Copyright (c) 2011 Picochip Ltd., Jamie Iles
|
|
*
|
|
* Modified from mach-picoxcell/time.c
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* 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, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#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/sched_clock.h>
|
|
|
|
static void timer_get_base_and_rate(struct device_node *np,
|
|
void __iomem **base, u32 *rate)
|
|
{
|
|
struct clk *timer_clk;
|
|
struct clk *pclk;
|
|
|
|
*base = of_iomap(np, 0);
|
|
|
|
if (!*base)
|
|
panic("Unable to map regs for %s", np->name);
|
|
|
|
/*
|
|
* 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 %s is present, but could not be activated\n",
|
|
np->name);
|
|
|
|
timer_clk = of_clk_get_by_name(np, "timer");
|
|
if (IS_ERR(timer_clk))
|
|
goto try_clock_freq;
|
|
|
|
if (!clk_prepare_enable(timer_clk)) {
|
|
*rate = clk_get_rate(timer_clk);
|
|
return;
|
|
}
|
|
|
|
try_clock_freq:
|
|
if (of_property_read_u32(np, "clock-freq", rate) &&
|
|
of_property_read_u32(np, "clock-frequency", rate))
|
|
panic("No clock nor clock-frequency property for %s", np->name);
|
|
}
|
|
|
|
static void add_clockevent(struct device_node *event_timer)
|
|
{
|
|
void __iomem *iobase;
|
|
struct dw_apb_clock_event_device *ced;
|
|
u32 irq, rate;
|
|
|
|
irq = irq_of_parse_and_map(event_timer, 0);
|
|
if (irq == 0)
|
|
panic("No IRQ for clock event timer");
|
|
|
|
timer_get_base_and_rate(event_timer, &iobase, &rate);
|
|
|
|
ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq,
|
|
rate);
|
|
if (!ced)
|
|
panic("Unable to initialise clockevent device");
|
|
|
|
dw_apb_clockevent_register(ced);
|
|
}
|
|
|
|
static void __iomem *sched_io_base;
|
|
static u32 sched_rate;
|
|
|
|
static void add_clocksource(struct device_node *source_timer)
|
|
{
|
|
void __iomem *iobase;
|
|
struct dw_apb_clocksource *cs;
|
|
u32 rate;
|
|
|
|
timer_get_base_and_rate(source_timer, &iobase, &rate);
|
|
|
|
cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate);
|
|
if (!cs)
|
|
panic("Unable to initialise clocksource device");
|
|
|
|
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;
|
|
}
|
|
|
|
static u32 read_sched_clock(void)
|
|
{
|
|
return __raw_readl(sched_io_base);
|
|
}
|
|
|
|
static const struct of_device_id sptimer_ids[] __initconst = {
|
|
{ .compatible = "picochip,pc3x2-rtc" },
|
|
{ .compatible = "snps,dw-apb-timer-sp" },
|
|
{ /* Sentinel */ },
|
|
};
|
|
|
|
static void 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);
|
|
}
|
|
|
|
setup_sched_clock(read_sched_clock, 32, sched_rate);
|
|
}
|
|
|
|
static int num_called;
|
|
static void __init dw_apb_timer_init(struct device_node *timer)
|
|
{
|
|
switch (num_called) {
|
|
case 0:
|
|
pr_debug("%s: found clockevent timer\n", __func__);
|
|
add_clockevent(timer);
|
|
of_node_put(timer);
|
|
break;
|
|
case 1:
|
|
pr_debug("%s: found clocksource timer\n", __func__);
|
|
add_clocksource(timer);
|
|
of_node_put(timer);
|
|
init_sched_clock();
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
num_called++;
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(pc3x2_timer, "picochip,pc3x2-timer", dw_apb_timer_init);
|
|
CLOCKSOURCE_OF_DECLARE(apb_timer, "snps,dw-apb-timer-osc", dw_apb_timer_init);
|