261 lines
6.5 KiB
C
261 lines
6.5 KiB
C
/*
|
|
* Copyright (C) 2010 Google, Inc.
|
|
*
|
|
* Author:
|
|
* Colin Cross <ccross@google.com>
|
|
*
|
|
* This software is licensed under the terms of the GNU General Public
|
|
* License version 2, as published by the Free Software Foundation, and
|
|
* may be copied, distributed, and modified under those terms.
|
|
*
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/err.h>
|
|
#include <linux/time.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/clockchips.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/io.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_irq.h>
|
|
#include <linux/sched_clock.h>
|
|
#include <linux/delay.h>
|
|
|
|
#include <asm/mach/time.h>
|
|
#include <asm/smp_twd.h>
|
|
|
|
#define RTC_SECONDS 0x08
|
|
#define RTC_SHADOW_SECONDS 0x0c
|
|
#define RTC_MILLISECONDS 0x10
|
|
|
|
#define TIMERUS_CNTR_1US 0x10
|
|
#define TIMERUS_USEC_CFG 0x14
|
|
#define TIMERUS_CNTR_FREEZE 0x4c
|
|
|
|
#define TIMER1_BASE 0x0
|
|
#define TIMER2_BASE 0x8
|
|
#define TIMER3_BASE 0x50
|
|
#define TIMER4_BASE 0x58
|
|
|
|
#define TIMER_PTV 0x0
|
|
#define TIMER_PCR 0x4
|
|
|
|
static void __iomem *timer_reg_base;
|
|
static void __iomem *rtc_base;
|
|
|
|
static struct timespec64 persistent_ts;
|
|
static u64 persistent_ms, last_persistent_ms;
|
|
|
|
static struct delay_timer tegra_delay_timer;
|
|
|
|
#define timer_writel(value, reg) \
|
|
writel_relaxed(value, timer_reg_base + (reg))
|
|
#define timer_readl(reg) \
|
|
readl_relaxed(timer_reg_base + (reg))
|
|
|
|
static int tegra_timer_set_next_event(unsigned long cycles,
|
|
struct clock_event_device *evt)
|
|
{
|
|
u32 reg;
|
|
|
|
reg = 0x80000000 | ((cycles > 1) ? (cycles-1) : 0);
|
|
timer_writel(reg, TIMER3_BASE + TIMER_PTV);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline void timer_shutdown(struct clock_event_device *evt)
|
|
{
|
|
timer_writel(0, TIMER3_BASE + TIMER_PTV);
|
|
}
|
|
|
|
static int tegra_timer_shutdown(struct clock_event_device *evt)
|
|
{
|
|
timer_shutdown(evt);
|
|
return 0;
|
|
}
|
|
|
|
static int tegra_timer_set_periodic(struct clock_event_device *evt)
|
|
{
|
|
u32 reg = 0xC0000000 | ((1000000 / HZ) - 1);
|
|
|
|
timer_shutdown(evt);
|
|
timer_writel(reg, TIMER3_BASE + TIMER_PTV);
|
|
return 0;
|
|
}
|
|
|
|
static struct clock_event_device tegra_clockevent = {
|
|
.name = "timer0",
|
|
.rating = 300,
|
|
.features = CLOCK_EVT_FEAT_ONESHOT |
|
|
CLOCK_EVT_FEAT_PERIODIC |
|
|
CLOCK_EVT_FEAT_DYNIRQ,
|
|
.set_next_event = tegra_timer_set_next_event,
|
|
.set_state_shutdown = tegra_timer_shutdown,
|
|
.set_state_periodic = tegra_timer_set_periodic,
|
|
.set_state_oneshot = tegra_timer_shutdown,
|
|
.tick_resume = tegra_timer_shutdown,
|
|
};
|
|
|
|
static u64 notrace tegra_read_sched_clock(void)
|
|
{
|
|
return timer_readl(TIMERUS_CNTR_1US);
|
|
}
|
|
|
|
/*
|
|
* tegra_rtc_read - Reads the Tegra RTC registers
|
|
* Care must be taken that this funciton is not called while the
|
|
* tegra_rtc driver could be executing to avoid race conditions
|
|
* on the RTC shadow register
|
|
*/
|
|
static u64 tegra_rtc_read_ms(void)
|
|
{
|
|
u32 ms = readl(rtc_base + RTC_MILLISECONDS);
|
|
u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
|
|
return (u64)s * MSEC_PER_SEC + ms;
|
|
}
|
|
|
|
/*
|
|
* tegra_read_persistent_clock64 - Return time from a persistent clock.
|
|
*
|
|
* Reads the time from a source which isn't disabled during PM, the
|
|
* 32k sync timer. Convert the cycles elapsed since last read into
|
|
* nsecs and adds to a monotonically increasing timespec64.
|
|
* Care must be taken that this funciton is not called while the
|
|
* tegra_rtc driver could be executing to avoid race conditions
|
|
* on the RTC shadow register
|
|
*/
|
|
static void tegra_read_persistent_clock64(struct timespec64 *ts)
|
|
{
|
|
u64 delta;
|
|
|
|
last_persistent_ms = persistent_ms;
|
|
persistent_ms = tegra_rtc_read_ms();
|
|
delta = persistent_ms - last_persistent_ms;
|
|
|
|
timespec64_add_ns(&persistent_ts, delta * NSEC_PER_MSEC);
|
|
*ts = persistent_ts;
|
|
}
|
|
|
|
static unsigned long tegra_delay_timer_read_counter_long(void)
|
|
{
|
|
return readl(timer_reg_base + TIMERUS_CNTR_1US);
|
|
}
|
|
|
|
static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct clock_event_device *evt = (struct clock_event_device *)dev_id;
|
|
timer_writel(1<<30, TIMER3_BASE + TIMER_PCR);
|
|
evt->event_handler(evt);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct irqaction tegra_timer_irq = {
|
|
.name = "timer0",
|
|
.flags = IRQF_TIMER | IRQF_TRIGGER_HIGH,
|
|
.handler = tegra_timer_interrupt,
|
|
.dev_id = &tegra_clockevent,
|
|
};
|
|
|
|
static void __init tegra20_init_timer(struct device_node *np)
|
|
{
|
|
struct clk *clk;
|
|
unsigned long rate;
|
|
int ret;
|
|
|
|
timer_reg_base = of_iomap(np, 0);
|
|
if (!timer_reg_base) {
|
|
pr_err("Can't map timer registers\n");
|
|
BUG();
|
|
}
|
|
|
|
tegra_timer_irq.irq = irq_of_parse_and_map(np, 2);
|
|
if (tegra_timer_irq.irq <= 0) {
|
|
pr_err("Failed to map timer IRQ\n");
|
|
BUG();
|
|
}
|
|
|
|
clk = of_clk_get(np, 0);
|
|
if (IS_ERR(clk)) {
|
|
pr_warn("Unable to get timer clock. Assuming 12Mhz input clock.\n");
|
|
rate = 12000000;
|
|
} else {
|
|
clk_prepare_enable(clk);
|
|
rate = clk_get_rate(clk);
|
|
}
|
|
|
|
switch (rate) {
|
|
case 12000000:
|
|
timer_writel(0x000b, TIMERUS_USEC_CFG);
|
|
break;
|
|
case 13000000:
|
|
timer_writel(0x000c, TIMERUS_USEC_CFG);
|
|
break;
|
|
case 19200000:
|
|
timer_writel(0x045f, TIMERUS_USEC_CFG);
|
|
break;
|
|
case 26000000:
|
|
timer_writel(0x0019, TIMERUS_USEC_CFG);
|
|
break;
|
|
default:
|
|
WARN(1, "Unknown clock rate");
|
|
}
|
|
|
|
sched_clock_register(tegra_read_sched_clock, 32, 1000000);
|
|
|
|
if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
|
|
"timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) {
|
|
pr_err("Failed to register clocksource\n");
|
|
BUG();
|
|
}
|
|
|
|
tegra_delay_timer.read_current_timer =
|
|
tegra_delay_timer_read_counter_long;
|
|
tegra_delay_timer.freq = 1000000;
|
|
register_current_timer_delay(&tegra_delay_timer);
|
|
|
|
ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);
|
|
if (ret) {
|
|
pr_err("Failed to register timer IRQ: %d\n", ret);
|
|
BUG();
|
|
}
|
|
|
|
tegra_clockevent.cpumask = cpu_all_mask;
|
|
tegra_clockevent.irq = tegra_timer_irq.irq;
|
|
clockevents_config_and_register(&tegra_clockevent, 1000000,
|
|
0x1, 0x1fffffff);
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra20_init_timer);
|
|
|
|
static void __init tegra20_init_rtc(struct device_node *np)
|
|
{
|
|
struct clk *clk;
|
|
|
|
rtc_base = of_iomap(np, 0);
|
|
if (!rtc_base) {
|
|
pr_err("Can't map RTC registers");
|
|
BUG();
|
|
}
|
|
|
|
/*
|
|
* rtc registers are used by read_persistent_clock, keep the rtc clock
|
|
* enabled
|
|
*/
|
|
clk = of_clk_get(np, 0);
|
|
if (IS_ERR(clk))
|
|
pr_warn("Unable to get rtc-tegra clock\n");
|
|
else
|
|
clk_prepare_enable(clk);
|
|
|
|
register_persistent_clock(NULL, tegra_read_persistent_clock64);
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);
|