149 строки
3.8 KiB
C
149 строки
3.8 KiB
C
/*
|
|
* Allwinner A1X SoCs timer handling.
|
|
*
|
|
* Copyright (C) 2012 Maxime Ripard
|
|
*
|
|
* Maxime Ripard <maxime.ripard@free-electrons.com>
|
|
*
|
|
* Based on code from
|
|
* Allwinner Technology Co., Ltd. <www.allwinnertech.com>
|
|
* Benn Huang <benn@allwinnertech.com>
|
|
*
|
|
* 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/of.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_irq.h>
|
|
|
|
#define TIMER_IRQ_EN_REG 0x00
|
|
#define TIMER_IRQ_EN(val) (1 << val)
|
|
#define TIMER_IRQ_ST_REG 0x04
|
|
#define TIMER_CTL_REG(val) (0x10 * val + 0x10)
|
|
#define TIMER_CTL_ENABLE (1 << 0)
|
|
#define TIMER_CTL_AUTORELOAD (1 << 1)
|
|
#define TIMER_CTL_ONESHOT (1 << 7)
|
|
#define TIMER_INTVAL_REG(val) (0x10 * val + 0x14)
|
|
#define TIMER_CNTVAL_REG(val) (0x10 * val + 0x18)
|
|
|
|
#define TIMER_SCAL 16
|
|
|
|
static void __iomem *timer_base;
|
|
|
|
static void sun4i_clkevt_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *clk)
|
|
{
|
|
u32 u = readl(timer_base + TIMER_CTL_REG(0));
|
|
|
|
switch (mode) {
|
|
case CLOCK_EVT_MODE_PERIODIC:
|
|
u &= ~(TIMER_CTL_ONESHOT);
|
|
writel(u | TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG(0));
|
|
break;
|
|
|
|
case CLOCK_EVT_MODE_ONESHOT:
|
|
writel(u | TIMER_CTL_ONESHOT, timer_base + TIMER_CTL_REG(0));
|
|
break;
|
|
case CLOCK_EVT_MODE_UNUSED:
|
|
case CLOCK_EVT_MODE_SHUTDOWN:
|
|
default:
|
|
writel(u & ~(TIMER_CTL_ENABLE), timer_base + TIMER_CTL_REG(0));
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int sun4i_clkevt_next_event(unsigned long evt,
|
|
struct clock_event_device *unused)
|
|
{
|
|
u32 u = readl(timer_base + TIMER_CTL_REG(0));
|
|
writel(evt, timer_base + TIMER_CNTVAL_REG(0));
|
|
writel(u | TIMER_CTL_ENABLE | TIMER_CTL_AUTORELOAD,
|
|
timer_base + TIMER_CTL_REG(0));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct clock_event_device sun4i_clockevent = {
|
|
.name = "sun4i_tick",
|
|
.rating = 300,
|
|
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
|
|
.set_mode = sun4i_clkevt_mode,
|
|
.set_next_event = sun4i_clkevt_next_event,
|
|
};
|
|
|
|
|
|
static irqreturn_t sun4i_timer_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct clock_event_device *evt = (struct clock_event_device *)dev_id;
|
|
|
|
writel(0x1, timer_base + TIMER_IRQ_ST_REG);
|
|
evt->event_handler(evt);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct irqaction sun4i_timer_irq = {
|
|
.name = "sun4i_timer0",
|
|
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
|
|
.handler = sun4i_timer_interrupt,
|
|
.dev_id = &sun4i_clockevent,
|
|
};
|
|
|
|
static void __init sun4i_timer_init(struct device_node *node)
|
|
{
|
|
unsigned long rate = 0;
|
|
struct clk *clk;
|
|
int ret, irq;
|
|
u32 val;
|
|
|
|
timer_base = of_iomap(node, 0);
|
|
if (!timer_base)
|
|
panic("Can't map registers");
|
|
|
|
irq = irq_of_parse_and_map(node, 0);
|
|
if (irq <= 0)
|
|
panic("Can't parse IRQ");
|
|
|
|
clk = of_clk_get(node, 0);
|
|
if (IS_ERR(clk))
|
|
panic("Can't get timer clock");
|
|
|
|
rate = clk_get_rate(clk);
|
|
|
|
writel(rate / (TIMER_SCAL * HZ),
|
|
timer_base + TIMER_INTVAL_REG(0));
|
|
|
|
/* set clock source to HOSC, 16 pre-division */
|
|
val = readl(timer_base + TIMER_CTL_REG(0));
|
|
val &= ~(0x07 << 4);
|
|
val &= ~(0x03 << 2);
|
|
val |= (4 << 4) | (1 << 2);
|
|
writel(val, timer_base + TIMER_CTL_REG(0));
|
|
|
|
/* set mode to auto reload */
|
|
val = readl(timer_base + TIMER_CTL_REG(0));
|
|
writel(val | TIMER_CTL_AUTORELOAD, timer_base + TIMER_CTL_REG(0));
|
|
|
|
ret = setup_irq(irq, &sun4i_timer_irq);
|
|
if (ret)
|
|
pr_warn("failed to setup irq %d\n", irq);
|
|
|
|
/* Enable timer0 interrupt */
|
|
val = readl(timer_base + TIMER_IRQ_EN_REG);
|
|
writel(val | TIMER_IRQ_EN(0), timer_base + TIMER_IRQ_EN_REG);
|
|
|
|
sun4i_clockevent.cpumask = cpumask_of(0);
|
|
|
|
clockevents_config_and_register(&sun4i_clockevent, rate / TIMER_SCAL,
|
|
0x1, 0xff);
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(sun4i, "allwinner,sun4i-timer",
|
|
sun4i_timer_init);
|