mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 08:31:55 +00:00
c8af34b4db
Replace the driver-specific thread-safe shared register API by the recently introduced atomic_io_clear_set(). Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
315 lines
7.9 KiB
C
315 lines
7.9 KiB
C
/*
|
|
* Marvell Armada 370/XP SoC timer handling.
|
|
*
|
|
* Copyright (C) 2012 Marvell
|
|
*
|
|
* Lior Amsalem <alior@marvell.com>
|
|
* Gregory CLEMENT <gregory.clement@free-electrons.com>
|
|
* Thomas Petazzoni <thomas.petazzoni@free-electrons.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.
|
|
*
|
|
* Timer 0 is used as free-running clocksource, while timer 1 is
|
|
* used as clock_event_device.
|
|
*
|
|
* ---
|
|
* Clocksource driver for Armada 370 and Armada XP SoC.
|
|
* This driver implements one compatible string for each SoC, given
|
|
* each has its own characteristics:
|
|
*
|
|
* * Armada 370 has no 25 MHz fixed timer.
|
|
*
|
|
* * Armada XP cannot work properly without such 25 MHz fixed timer as
|
|
* doing otherwise leads to using a clocksource whose frequency varies
|
|
* when doing cpufreq frequency changes.
|
|
*
|
|
* See Documentation/devicetree/bindings/timer/marvell,armada-370-xp-timer.txt
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/clockchips.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_irq.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/module.h>
|
|
#include <linux/sched_clock.h>
|
|
#include <linux/percpu.h>
|
|
|
|
/*
|
|
* Timer block registers.
|
|
*/
|
|
#define TIMER_CTRL_OFF 0x0000
|
|
#define TIMER0_EN BIT(0)
|
|
#define TIMER0_RELOAD_EN BIT(1)
|
|
#define TIMER0_25MHZ BIT(11)
|
|
#define TIMER0_DIV(div) ((div) << 19)
|
|
#define TIMER1_EN BIT(2)
|
|
#define TIMER1_RELOAD_EN BIT(3)
|
|
#define TIMER1_25MHZ BIT(12)
|
|
#define TIMER1_DIV(div) ((div) << 22)
|
|
#define TIMER_EVENTS_STATUS 0x0004
|
|
#define TIMER0_CLR_MASK (~0x1)
|
|
#define TIMER1_CLR_MASK (~0x100)
|
|
#define TIMER0_RELOAD_OFF 0x0010
|
|
#define TIMER0_VAL_OFF 0x0014
|
|
#define TIMER1_RELOAD_OFF 0x0018
|
|
#define TIMER1_VAL_OFF 0x001c
|
|
|
|
#define LCL_TIMER_EVENTS_STATUS 0x0028
|
|
/* Global timers are connected to the coherency fabric clock, and the
|
|
below divider reduces their incrementing frequency. */
|
|
#define TIMER_DIVIDER_SHIFT 5
|
|
#define TIMER_DIVIDER (1 << TIMER_DIVIDER_SHIFT)
|
|
|
|
/*
|
|
* SoC-specific data.
|
|
*/
|
|
static void __iomem *timer_base, *local_base;
|
|
static unsigned int timer_clk;
|
|
static bool timer25Mhz = true;
|
|
static u32 enable_mask;
|
|
|
|
/*
|
|
* Number of timer ticks per jiffy.
|
|
*/
|
|
static u32 ticks_per_jiffy;
|
|
|
|
static struct clock_event_device __percpu *armada_370_xp_evt;
|
|
|
|
static void local_timer_ctrl_clrset(u32 clr, u32 set)
|
|
{
|
|
writel((readl(local_base + TIMER_CTRL_OFF) & ~clr) | set,
|
|
local_base + TIMER_CTRL_OFF);
|
|
}
|
|
|
|
static u64 notrace armada_370_xp_read_sched_clock(void)
|
|
{
|
|
return ~readl(timer_base + TIMER0_VAL_OFF);
|
|
}
|
|
|
|
/*
|
|
* Clockevent handling.
|
|
*/
|
|
static int
|
|
armada_370_xp_clkevt_next_event(unsigned long delta,
|
|
struct clock_event_device *dev)
|
|
{
|
|
/*
|
|
* Clear clockevent timer interrupt.
|
|
*/
|
|
writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
|
|
|
|
/*
|
|
* Setup new clockevent timer value.
|
|
*/
|
|
writel(delta, local_base + TIMER0_VAL_OFF);
|
|
|
|
/*
|
|
* Enable the timer.
|
|
*/
|
|
local_timer_ctrl_clrset(TIMER0_RELOAD_EN, enable_mask);
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
armada_370_xp_clkevt_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *dev)
|
|
{
|
|
if (mode == CLOCK_EVT_MODE_PERIODIC) {
|
|
|
|
/*
|
|
* Setup timer to fire at 1/HZ intervals.
|
|
*/
|
|
writel(ticks_per_jiffy - 1, local_base + TIMER0_RELOAD_OFF);
|
|
writel(ticks_per_jiffy - 1, local_base + TIMER0_VAL_OFF);
|
|
|
|
/*
|
|
* Enable timer.
|
|
*/
|
|
local_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | enable_mask);
|
|
} else {
|
|
/*
|
|
* Disable timer.
|
|
*/
|
|
local_timer_ctrl_clrset(TIMER0_EN, 0);
|
|
|
|
/*
|
|
* ACK pending timer interrupt.
|
|
*/
|
|
writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
|
|
}
|
|
}
|
|
|
|
static int armada_370_xp_clkevt_irq;
|
|
|
|
static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id)
|
|
{
|
|
/*
|
|
* ACK timer interrupt and call event handler.
|
|
*/
|
|
struct clock_event_device *evt = dev_id;
|
|
|
|
writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
|
|
evt->event_handler(evt);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/*
|
|
* Setup the local clock events for a CPU.
|
|
*/
|
|
static int armada_370_xp_timer_setup(struct clock_event_device *evt)
|
|
{
|
|
u32 clr = 0, set = 0;
|
|
int cpu = smp_processor_id();
|
|
|
|
if (timer25Mhz)
|
|
set = TIMER0_25MHZ;
|
|
else
|
|
clr = TIMER0_25MHZ;
|
|
local_timer_ctrl_clrset(clr, set);
|
|
|
|
evt->name = "armada_370_xp_per_cpu_tick",
|
|
evt->features = CLOCK_EVT_FEAT_ONESHOT |
|
|
CLOCK_EVT_FEAT_PERIODIC;
|
|
evt->shift = 32,
|
|
evt->rating = 300,
|
|
evt->set_next_event = armada_370_xp_clkevt_next_event,
|
|
evt->set_mode = armada_370_xp_clkevt_mode,
|
|
evt->irq = armada_370_xp_clkevt_irq;
|
|
evt->cpumask = cpumask_of(cpu);
|
|
|
|
clockevents_config_and_register(evt, timer_clk, 1, 0xfffffffe);
|
|
enable_percpu_irq(evt->irq, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void armada_370_xp_timer_stop(struct clock_event_device *evt)
|
|
{
|
|
evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
|
|
disable_percpu_irq(evt->irq);
|
|
}
|
|
|
|
static int armada_370_xp_timer_cpu_notify(struct notifier_block *self,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
/*
|
|
* Grab cpu pointer in each case to avoid spurious
|
|
* preemptible warnings
|
|
*/
|
|
switch (action & ~CPU_TASKS_FROZEN) {
|
|
case CPU_STARTING:
|
|
armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
|
|
break;
|
|
case CPU_DYING:
|
|
armada_370_xp_timer_stop(this_cpu_ptr(armada_370_xp_evt));
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block armada_370_xp_timer_cpu_nb = {
|
|
.notifier_call = armada_370_xp_timer_cpu_notify,
|
|
};
|
|
|
|
static void __init armada_370_xp_timer_common_init(struct device_node *np)
|
|
{
|
|
u32 clr = 0, set = 0;
|
|
int res;
|
|
|
|
timer_base = of_iomap(np, 0);
|
|
WARN_ON(!timer_base);
|
|
local_base = of_iomap(np, 1);
|
|
|
|
if (timer25Mhz) {
|
|
set = TIMER0_25MHZ;
|
|
enable_mask = TIMER0_EN;
|
|
} else {
|
|
clr = TIMER0_25MHZ;
|
|
enable_mask = TIMER0_EN | TIMER0_DIV(TIMER_DIVIDER_SHIFT);
|
|
}
|
|
atomic_io_modify(timer_base + TIMER_CTRL_OFF, clr | set, set);
|
|
local_timer_ctrl_clrset(clr, set);
|
|
|
|
/*
|
|
* We use timer 0 as clocksource, and private(local) timer 0
|
|
* for clockevents
|
|
*/
|
|
armada_370_xp_clkevt_irq = irq_of_parse_and_map(np, 4);
|
|
|
|
ticks_per_jiffy = (timer_clk + HZ / 2) / HZ;
|
|
|
|
/*
|
|
* Setup free-running clocksource timer (interrupts
|
|
* disabled).
|
|
*/
|
|
writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
|
|
writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
|
|
|
|
atomic_io_modify(timer_base + TIMER_CTRL_OFF,
|
|
TIMER0_RELOAD_EN | enable_mask,
|
|
TIMER0_RELOAD_EN | enable_mask);
|
|
|
|
/*
|
|
* Set scale and timer for sched_clock.
|
|
*/
|
|
sched_clock_register(armada_370_xp_read_sched_clock, 32, timer_clk);
|
|
|
|
clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
|
|
"armada_370_xp_clocksource",
|
|
timer_clk, 300, 32, clocksource_mmio_readl_down);
|
|
|
|
register_cpu_notifier(&armada_370_xp_timer_cpu_nb);
|
|
|
|
armada_370_xp_evt = alloc_percpu(struct clock_event_device);
|
|
|
|
|
|
/*
|
|
* Setup clockevent timer (interrupt-driven).
|
|
*/
|
|
res = request_percpu_irq(armada_370_xp_clkevt_irq,
|
|
armada_370_xp_timer_interrupt,
|
|
"armada_370_xp_per_cpu_tick",
|
|
armada_370_xp_evt);
|
|
/* Immediately configure the timer on the boot CPU */
|
|
if (!res)
|
|
armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
|
|
}
|
|
|
|
static void __init armada_xp_timer_init(struct device_node *np)
|
|
{
|
|
struct clk *clk = of_clk_get_by_name(np, "fixed");
|
|
|
|
/* The 25Mhz fixed clock is mandatory, and must always be available */
|
|
BUG_ON(IS_ERR(clk));
|
|
timer_clk = clk_get_rate(clk);
|
|
|
|
armada_370_xp_timer_common_init(np);
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(armada_xp, "marvell,armada-xp-timer",
|
|
armada_xp_timer_init);
|
|
|
|
static void __init armada_370_timer_init(struct device_node *np)
|
|
{
|
|
struct clk *clk = of_clk_get(np, 0);
|
|
|
|
BUG_ON(IS_ERR(clk));
|
|
timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
|
|
timer25Mhz = false;
|
|
|
|
armada_370_xp_timer_common_init(np);
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(armada_370, "marvell,armada-370-timer",
|
|
armada_370_timer_init);
|