124 lines
2.9 KiB
C
124 lines
2.9 KiB
C
/*
|
|
* Cirrus Logic CLPS711X clocksource driver
|
|
*
|
|
* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/clockchips.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/io.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_irq.h>
|
|
#include <linux/sched_clock.h>
|
|
#include <linux/slab.h>
|
|
|
|
enum {
|
|
CLPS711X_CLKSRC_CLOCKSOURCE,
|
|
CLPS711X_CLKSRC_CLOCKEVENT,
|
|
};
|
|
|
|
static void __iomem *tcd;
|
|
|
|
static u64 notrace clps711x_sched_clock_read(void)
|
|
{
|
|
return ~readw(tcd);
|
|
}
|
|
|
|
static int __init _clps711x_clksrc_init(struct clk *clock, void __iomem *base)
|
|
{
|
|
unsigned long rate;
|
|
|
|
if (!base)
|
|
return -ENOMEM;
|
|
if (IS_ERR(clock))
|
|
return PTR_ERR(clock);
|
|
|
|
rate = clk_get_rate(clock);
|
|
|
|
tcd = base;
|
|
|
|
clocksource_mmio_init(tcd, "clps711x-clocksource", rate, 300, 16,
|
|
clocksource_mmio_readw_down);
|
|
|
|
sched_clock_register(clps711x_sched_clock_read, 16, rate);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static irqreturn_t clps711x_timer_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct clock_event_device *evt = dev_id;
|
|
|
|
evt->event_handler(evt);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int __init _clps711x_clkevt_init(struct clk *clock, void __iomem *base,
|
|
unsigned int irq)
|
|
{
|
|
struct clock_event_device *clkevt;
|
|
unsigned long rate;
|
|
|
|
if (!irq)
|
|
return -EINVAL;
|
|
if (!base)
|
|
return -ENOMEM;
|
|
if (IS_ERR(clock))
|
|
return PTR_ERR(clock);
|
|
|
|
clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
|
|
if (!clkevt)
|
|
return -ENOMEM;
|
|
|
|
rate = clk_get_rate(clock);
|
|
|
|
/* Set Timer prescaler */
|
|
writew(DIV_ROUND_CLOSEST(rate, HZ), base);
|
|
|
|
clkevt->name = "clps711x-clockevent";
|
|
clkevt->rating = 300;
|
|
clkevt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_C3STOP;
|
|
clkevt->cpumask = cpumask_of(0);
|
|
clockevents_config_and_register(clkevt, HZ, 0, 0);
|
|
|
|
return request_irq(irq, clps711x_timer_interrupt, IRQF_TIMER,
|
|
"clps711x-timer", clkevt);
|
|
}
|
|
|
|
void __init clps711x_clksrc_init(void __iomem *tc1_base, void __iomem *tc2_base,
|
|
unsigned int irq)
|
|
{
|
|
struct clk *tc1 = clk_get_sys("clps711x-timer.0", NULL);
|
|
struct clk *tc2 = clk_get_sys("clps711x-timer.1", NULL);
|
|
|
|
BUG_ON(_clps711x_clksrc_init(tc1, tc1_base));
|
|
BUG_ON(_clps711x_clkevt_init(tc2, tc2_base, irq));
|
|
}
|
|
|
|
#ifdef CONFIG_CLKSRC_OF
|
|
static int __init clps711x_timer_init(struct device_node *np)
|
|
{
|
|
unsigned int irq = irq_of_parse_and_map(np, 0);
|
|
struct clk *clock = of_clk_get(np, 0);
|
|
void __iomem *base = of_iomap(np, 0);
|
|
|
|
switch (of_alias_get_id(np, "timer")) {
|
|
case CLPS711X_CLKSRC_CLOCKSOURCE:
|
|
return _clps711x_clksrc_init(clock, base);
|
|
case CLPS711X_CLKSRC_CLOCKEVENT:
|
|
return _clps711x_clkevt_init(clock, base, irq);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(clps711x, "cirrus,ep7209-timer", clps711x_timer_init);
|
|
#endif
|