linux/drivers/clocksource/timer-tegra20.c

412 lines
10 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/clk.h>
#include <linux/clockchips.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/percpu.h>
#include <linux/sched_clock.h>
#include <linux/time.h>
#include "timer-of.h"
#ifdef CONFIG_ARM
#include <asm/mach/time.h>
#endif
#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 TIMER_PTV 0x0
#define TIMER_PTV_EN BIT(31)
#define TIMER_PTV_PER BIT(30)
#define TIMER_PCR 0x4
#define TIMER_PCR_INTR_CLR BIT(30)
#ifdef CONFIG_ARM
#define TIMER_CPU0 0x50 /* TIMER3 */
#else
#define TIMER_CPU0 0x90 /* TIMER10 */
#define TIMER10_IRQ_IDX 10
#define IRQ_IDX_FOR_CPU(cpu) (TIMER10_IRQ_IDX + cpu)
#endif
#define TIMER_BASE_FOR_CPU(cpu) (TIMER_CPU0 + (cpu) * 8)
static u32 usec_config;
static void __iomem *timer_reg_base;
#ifdef CONFIG_ARM
static void __iomem *rtc_base;
static struct timespec64 persistent_ts;
static u64 persistent_ms, last_persistent_ms;
static struct delay_timer tegra_delay_timer;
#endif
static int tegra_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
void __iomem *reg_base = timer_of_base(to_timer_of(evt));
writel(TIMER_PTV_EN |
((cycles > 1) ? (cycles - 1) : 0), /* n+1 scheme */
reg_base + TIMER_PTV);
return 0;
}
static int tegra_timer_shutdown(struct clock_event_device *evt)
{
void __iomem *reg_base = timer_of_base(to_timer_of(evt));
writel(0, reg_base + TIMER_PTV);
return 0;
}
static int tegra_timer_set_periodic(struct clock_event_device *evt)
{
void __iomem *reg_base = timer_of_base(to_timer_of(evt));
writel(TIMER_PTV_EN | TIMER_PTV_PER |
((timer_of_rate(to_timer_of(evt)) / HZ) - 1),
reg_base + TIMER_PTV);
return 0;
}
static irqreturn_t tegra_timer_isr(int irq, void *dev_id)
{
struct clock_event_device *evt = (struct clock_event_device *)dev_id;
void __iomem *reg_base = timer_of_base(to_timer_of(evt));
writel(TIMER_PCR_INTR_CLR, reg_base + TIMER_PCR);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static void tegra_timer_suspend(struct clock_event_device *evt)
{
void __iomem *reg_base = timer_of_base(to_timer_of(evt));
writel(TIMER_PCR_INTR_CLR, reg_base + TIMER_PCR);
}
static void tegra_timer_resume(struct clock_event_device *evt)
{
writel(usec_config, timer_reg_base + TIMERUS_USEC_CFG);
}
#ifdef CONFIG_ARM64
static DEFINE_PER_CPU(struct timer_of, tegra_to) = {
.flags = TIMER_OF_CLOCK | TIMER_OF_BASE,
.clkevt = {
.name = "tegra_timer",
.rating = 460,
.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
.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,
.suspend = tegra_timer_suspend,
.resume = tegra_timer_resume,
},
};
static int tegra_timer_setup(unsigned int cpu)
{
struct timer_of *to = per_cpu_ptr(&tegra_to, cpu);
irq_force_affinity(to->clkevt.irq, cpumask_of(cpu));
enable_irq(to->clkevt.irq);
clockevents_config_and_register(&to->clkevt, timer_of_rate(to),
1, /* min */
0x1fffffff); /* 29 bits */
return 0;
}
static int tegra_timer_stop(unsigned int cpu)
{
struct timer_of *to = per_cpu_ptr(&tegra_to, cpu);
to->clkevt.set_state_shutdown(&to->clkevt);
disable_irq_nosync(to->clkevt.irq);
return 0;
}
#else /* CONFIG_ARM */
static struct timer_of tegra_to = {
.flags = TIMER_OF_CLOCK | TIMER_OF_BASE | TIMER_OF_IRQ,
.clkevt = {
.name = "tegra_timer",
.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,
.suspend = tegra_timer_suspend,
.resume = tegra_timer_resume,
.cpumask = cpu_possible_mask,
},
.of_irq = {
.index = 2,
.flags = IRQF_TIMER | IRQF_TRIGGER_HIGH,
.handler = tegra_timer_isr,
},
};
static u64 notrace tegra_read_sched_clock(void)
{
return readl(timer_reg_base + TIMERUS_CNTR_1US);
}
static unsigned long tegra_delay_timer_read_counter_long(void)
{
return readl(timer_reg_base + 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;
}
#endif
static int tegra_timer_common_init(struct device_node *np, struct timer_of *to)
{
int ret = 0;
ret = timer_of_init(np, to);
if (ret < 0)
goto out;
timer_reg_base = timer_of_base(to);
/*
* Configure microsecond timers to have 1MHz clock
* Config register is 0xqqww, where qq is "dividend", ww is "divisor"
* Uses n+1 scheme
*/
switch (timer_of_rate(to)) {
case 12000000:
usec_config = 0x000b; /* (11+1)/(0+1) */
break;
case 12800000:
usec_config = 0x043f; /* (63+1)/(4+1) */
break;
case 13000000:
usec_config = 0x000c; /* (12+1)/(0+1) */
break;
case 16800000:
usec_config = 0x0453; /* (83+1)/(4+1) */
break;
case 19200000:
usec_config = 0x045f; /* (95+1)/(4+1) */
break;
case 26000000:
usec_config = 0x0019; /* (25+1)/(0+1) */
break;
case 38400000:
usec_config = 0x04bf; /* (191+1)/(4+1) */
break;
case 48000000:
usec_config = 0x002f; /* (47+1)/(0+1) */
break;
default:
ret = -EINVAL;
goto out;
}
writel(usec_config, timer_of_base(to) + TIMERUS_USEC_CFG);
out:
return ret;
}
#ifdef CONFIG_ARM64
static int __init tegra_init_timer(struct device_node *np)
{
int cpu, ret = 0;
struct timer_of *to;
to = this_cpu_ptr(&tegra_to);
ret = tegra_timer_common_init(np, to);
if (ret < 0)
goto out;
for_each_possible_cpu(cpu) {
struct timer_of *cpu_to;
cpu_to = per_cpu_ptr(&tegra_to, cpu);
cpu_to->of_base.base = timer_reg_base + TIMER_BASE_FOR_CPU(cpu);
cpu_to->of_clk.rate = timer_of_rate(to);
cpu_to->clkevt.cpumask = cpumask_of(cpu);
cpu_to->clkevt.irq =
irq_of_parse_and_map(np, IRQ_IDX_FOR_CPU(cpu));
if (!cpu_to->clkevt.irq) {
pr_err("%s: can't map IRQ for CPU%d\n",
__func__, cpu);
ret = -EINVAL;
goto out;
}
irq_set_status_flags(cpu_to->clkevt.irq, IRQ_NOAUTOEN);
ret = request_irq(cpu_to->clkevt.irq, tegra_timer_isr,
IRQF_TIMER | IRQF_NOBALANCING,
cpu_to->clkevt.name, &cpu_to->clkevt);
if (ret) {
pr_err("%s: cannot setup irq %d for CPU%d\n",
__func__, cpu_to->clkevt.irq, cpu);
ret = -EINVAL;
goto out_irq;
}
}
cpuhp_setup_state(CPUHP_AP_TEGRA_TIMER_STARTING,
"AP_TEGRA_TIMER_STARTING", tegra_timer_setup,
tegra_timer_stop);
return ret;
out_irq:
for_each_possible_cpu(cpu) {
struct timer_of *cpu_to;
cpu_to = per_cpu_ptr(&tegra_to, cpu);
if (cpu_to->clkevt.irq) {
free_irq(cpu_to->clkevt.irq, &cpu_to->clkevt);
irq_dispose_mapping(cpu_to->clkevt.irq);
}
}
out:
timer_of_cleanup(to);
return ret;
}
#else /* CONFIG_ARM */
static int __init tegra_init_timer(struct device_node *np)
{
int ret = 0;
ret = tegra_timer_common_init(np, &tegra_to);
if (ret < 0)
goto out;
tegra_to.of_base.base = timer_reg_base + TIMER_BASE_FOR_CPU(0);
tegra_to.of_clk.rate = 1000000; /* microsecond timer */
sched_clock_register(tegra_read_sched_clock, 32,
timer_of_rate(&tegra_to));
ret = clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
"timer_us", timer_of_rate(&tegra_to),
300, 32, clocksource_mmio_readl_up);
if (ret) {
pr_err("Failed to register clocksource\n");
goto out;
}
tegra_delay_timer.read_current_timer =
tegra_delay_timer_read_counter_long;
tegra_delay_timer.freq = timer_of_rate(&tegra_to);
register_current_timer_delay(&tegra_delay_timer);
clockevents_config_and_register(&tegra_to.clkevt,
timer_of_rate(&tegra_to),
0x1,
0x1fffffff);
return ret;
out:
timer_of_cleanup(&tegra_to);
return ret;
}
static int __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\n");
return -ENXIO;
}
/*
* 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);
return register_persistent_clock(tegra_read_persistent_clock64);
}
TIMER_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);
#endif
TIMER_OF_DECLARE(tegra210_timer, "nvidia,tegra210-timer", tegra_init_timer);
TIMER_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra_init_timer);