https://github.com/torvalds/linux
Tip revision: f2906aa863381afb0015a9eb7fefad885d4e5a56 authored by Linus Torvalds on 06 June 2022, 00:18:54 UTC
Linux 5.19-rc1
Linux 5.19-rc1
Tip revision: f2906aa
timer-sp804.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* linux/drivers/clocksource/timer-sp.c
*
* Copyright (C) 1999 - 2003 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_clk.h>
#include <linux/of_irq.h>
#include <linux/sched_clock.h>
#include "timer-sp.h"
/* Hisilicon 64-bit timer(a variant of ARM SP804) */
#define HISI_TIMER_1_BASE 0x00
#define HISI_TIMER_2_BASE 0x40
#define HISI_TIMER_LOAD 0x00
#define HISI_TIMER_LOAD_H 0x04
#define HISI_TIMER_VALUE 0x08
#define HISI_TIMER_VALUE_H 0x0c
#define HISI_TIMER_CTRL 0x10
#define HISI_TIMER_INTCLR 0x14
#define HISI_TIMER_RIS 0x18
#define HISI_TIMER_MIS 0x1c
#define HISI_TIMER_BGLOAD 0x20
#define HISI_TIMER_BGLOAD_H 0x24
static struct sp804_timer arm_sp804_timer __initdata = {
.load = TIMER_LOAD,
.value = TIMER_VALUE,
.ctrl = TIMER_CTRL,
.intclr = TIMER_INTCLR,
.timer_base = {TIMER_1_BASE, TIMER_2_BASE},
.width = 32,
};
static struct sp804_timer hisi_sp804_timer __initdata = {
.load = HISI_TIMER_LOAD,
.load_h = HISI_TIMER_LOAD_H,
.value = HISI_TIMER_VALUE,
.value_h = HISI_TIMER_VALUE_H,
.ctrl = HISI_TIMER_CTRL,
.intclr = HISI_TIMER_INTCLR,
.timer_base = {HISI_TIMER_1_BASE, HISI_TIMER_2_BASE},
.width = 64,
};
static struct sp804_clkevt sp804_clkevt[NR_TIMERS];
static long __init sp804_get_clock_rate(struct clk *clk, const char *name)
{
int err;
if (!clk)
clk = clk_get_sys("sp804", name);
if (IS_ERR(clk)) {
pr_err("%s clock not found: %ld\n", name, PTR_ERR(clk));
return PTR_ERR(clk);
}
err = clk_prepare_enable(clk);
if (err) {
pr_err("clock failed to enable: %d\n", err);
clk_put(clk);
return err;
}
return clk_get_rate(clk);
}
static struct sp804_clkevt * __init sp804_clkevt_get(void __iomem *base)
{
int i;
for (i = 0; i < NR_TIMERS; i++) {
if (sp804_clkevt[i].base == base)
return &sp804_clkevt[i];
}
/* It's impossible to reach here */
WARN_ON(1);
return NULL;
}
static struct sp804_clkevt *sched_clkevt;
static u64 notrace sp804_read(void)
{
return ~readl_relaxed(sched_clkevt->value);
}
static int __init sp804_clocksource_and_sched_clock_init(void __iomem *base,
const char *name,
struct clk *clk,
int use_sched_clock)
{
long rate;
struct sp804_clkevt *clkevt;
rate = sp804_get_clock_rate(clk, name);
if (rate < 0)
return -EINVAL;
clkevt = sp804_clkevt_get(base);
writel(0, clkevt->ctrl);
writel(0xffffffff, clkevt->load);
writel(0xffffffff, clkevt->value);
if (clkevt->width == 64) {
writel(0xffffffff, clkevt->load_h);
writel(0xffffffff, clkevt->value_h);
}
writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
clkevt->ctrl);
clocksource_mmio_init(clkevt->value, name,
rate, 200, 32, clocksource_mmio_readl_down);
if (use_sched_clock) {
sched_clkevt = clkevt;
sched_clock_register(sp804_read, 32, rate);
}
return 0;
}
static struct sp804_clkevt *common_clkevt;
/*
* IRQ handler for the timer
*/
static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
/* clear the interrupt */
writel(1, common_clkevt->intclr);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static inline void timer_shutdown(struct clock_event_device *evt)
{
writel(0, common_clkevt->ctrl);
}
static int sp804_shutdown(struct clock_event_device *evt)
{
timer_shutdown(evt);
return 0;
}
static int sp804_set_periodic(struct clock_event_device *evt)
{
unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE |
TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
timer_shutdown(evt);
writel(common_clkevt->reload, common_clkevt->load);
writel(ctrl, common_clkevt->ctrl);
return 0;
}
static int sp804_set_next_event(unsigned long next,
struct clock_event_device *evt)
{
unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE |
TIMER_CTRL_ONESHOT | TIMER_CTRL_ENABLE;
writel(next, common_clkevt->load);
writel(ctrl, common_clkevt->ctrl);
return 0;
}
static struct clock_event_device sp804_clockevent = {
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT |
CLOCK_EVT_FEAT_DYNIRQ,
.set_state_shutdown = sp804_shutdown,
.set_state_periodic = sp804_set_periodic,
.set_state_oneshot = sp804_shutdown,
.tick_resume = sp804_shutdown,
.set_next_event = sp804_set_next_event,
.rating = 300,
};
static int __init sp804_clockevents_init(void __iomem *base, unsigned int irq,
struct clk *clk, const char *name)
{
struct clock_event_device *evt = &sp804_clockevent;
long rate;
rate = sp804_get_clock_rate(clk, name);
if (rate < 0)
return -EINVAL;
common_clkevt = sp804_clkevt_get(base);
common_clkevt->reload = DIV_ROUND_CLOSEST(rate, HZ);
evt->name = name;
evt->irq = irq;
evt->cpumask = cpu_possible_mask;
writel(0, common_clkevt->ctrl);
if (request_irq(irq, sp804_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
"timer", &sp804_clockevent))
pr_err("request_irq() failed\n");
clockevents_config_and_register(evt, rate, 0xf, 0xffffffff);
return 0;
}
static void __init sp804_clkevt_init(struct sp804_timer *timer, void __iomem *base)
{
int i;
for (i = 0; i < NR_TIMERS; i++) {
void __iomem *timer_base;
struct sp804_clkevt *clkevt;
timer_base = base + timer->timer_base[i];
clkevt = &sp804_clkevt[i];
clkevt->base = timer_base;
clkevt->load = timer_base + timer->load;
clkevt->load_h = timer_base + timer->load_h;
clkevt->value = timer_base + timer->value;
clkevt->value_h = timer_base + timer->value_h;
clkevt->ctrl = timer_base + timer->ctrl;
clkevt->intclr = timer_base + timer->intclr;
clkevt->width = timer->width;
}
}
static int __init sp804_of_init(struct device_node *np, struct sp804_timer *timer)
{
static bool initialized = false;
void __iomem *base;
void __iomem *timer1_base;
void __iomem *timer2_base;
int irq, ret = -EINVAL;
u32 irq_num = 0;
struct clk *clk1, *clk2;
const char *name = of_get_property(np, "compatible", NULL);
if (initialized) {
pr_debug("%pOF: skipping further SP804 timer device\n", np);
return 0;
}
base = of_iomap(np, 0);
if (!base)
return -ENXIO;
timer1_base = base + timer->timer_base[0];
timer2_base = base + timer->timer_base[1];
/* Ensure timers are disabled */
writel(0, timer1_base + timer->ctrl);
writel(0, timer2_base + timer->ctrl);
clk1 = of_clk_get(np, 0);
if (IS_ERR(clk1))
clk1 = NULL;
/* Get the 2nd clock if the timer has 3 timer clocks */
if (of_clk_get_parent_count(np) == 3) {
clk2 = of_clk_get(np, 1);
if (IS_ERR(clk2)) {
pr_err("%pOFn clock not found: %d\n", np,
(int)PTR_ERR(clk2));
clk2 = NULL;
}
} else
clk2 = clk1;
irq = irq_of_parse_and_map(np, 0);
if (irq <= 0)
goto err;
sp804_clkevt_init(timer, base);
of_property_read_u32(np, "arm,sp804-has-irq", &irq_num);
if (irq_num == 2) {
ret = sp804_clockevents_init(timer2_base, irq, clk2, name);
if (ret)
goto err;
ret = sp804_clocksource_and_sched_clock_init(timer1_base,
name, clk1, 1);
if (ret)
goto err;
} else {
ret = sp804_clockevents_init(timer1_base, irq, clk1, name);
if (ret)
goto err;
ret = sp804_clocksource_and_sched_clock_init(timer2_base,
name, clk2, 1);
if (ret)
goto err;
}
initialized = true;
return 0;
err:
iounmap(base);
return ret;
}
static int __init arm_sp804_of_init(struct device_node *np)
{
return sp804_of_init(np, &arm_sp804_timer);
}
TIMER_OF_DECLARE(sp804, "arm,sp804", arm_sp804_of_init);
static int __init hisi_sp804_of_init(struct device_node *np)
{
return sp804_of_init(np, &hisi_sp804_timer);
}
TIMER_OF_DECLARE(hisi_sp804, "hisilicon,sp804", hisi_sp804_of_init);
static int __init integrator_cp_of_init(struct device_node *np)
{
static int init_count = 0;
void __iomem *base;
int irq, ret = -EINVAL;
const char *name = of_get_property(np, "compatible", NULL);
struct clk *clk;
base = of_iomap(np, 0);
if (!base) {
pr_err("Failed to iomap\n");
return -ENXIO;
}
clk = of_clk_get(np, 0);
if (IS_ERR(clk)) {
pr_err("Failed to get clock\n");
return PTR_ERR(clk);
}
/* Ensure timer is disabled */
writel(0, base + arm_sp804_timer.ctrl);
if (init_count == 2 || !of_device_is_available(np))
goto err;
sp804_clkevt_init(&arm_sp804_timer, base);
if (!init_count) {
ret = sp804_clocksource_and_sched_clock_init(base,
name, clk, 0);
if (ret)
goto err;
} else {
irq = irq_of_parse_and_map(np, 0);
if (irq <= 0)
goto err;
ret = sp804_clockevents_init(base, irq, clk, name);
if (ret)
goto err;
}
init_count++;
return 0;
err:
iounmap(base);
return ret;
}
TIMER_OF_DECLARE(intcp, "arm,integrator-cp-timer", integrator_cp_of_init);