mirror of
https://github.com/torvalds/linux.git
synced 2025-10-31 16:48:26 +02:00
cd5375610b
System Tick Counter is present on Ralink SoCs RT3352 and MT7620. This driver has been in 'arch/mips/ralink' directory since the beggining of Ralink architecture support. However, it can be moved into a more proper place in 'drivers/clocksource'. Hence add it here adding also support for compile test targets and reducing LOC in architecture code folder. Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> Link: https://lore.kernel.org/r/20241028203643.191268-2-sergio.paracuellos@gmail.com Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
150 lines
3.7 KiB
C
150 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Ralink System Tick Counter driver present on RT3352 and MT7620 SoCs.
|
|
*
|
|
* Copyright (C) 2013 by John Crispin <john@phrozen.org>
|
|
*/
|
|
|
|
#include <linux/clockchips.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/reset.h>
|
|
#include <linux/init.h>
|
|
#include <linux/time.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_irq.h>
|
|
#include <linux/of_address.h>
|
|
|
|
#define SYSTICK_FREQ (50 * 1000)
|
|
|
|
#define SYSTICK_CONFIG 0x00
|
|
#define SYSTICK_COMPARE 0x04
|
|
#define SYSTICK_COUNT 0x08
|
|
|
|
/* route systick irq to mips irq 7 instead of the r4k-timer */
|
|
#define CFG_EXT_STK_EN 0x2
|
|
/* enable the counter */
|
|
#define CFG_CNT_EN 0x1
|
|
|
|
struct systick_device {
|
|
void __iomem *membase;
|
|
struct clock_event_device dev;
|
|
int irq_requested;
|
|
int freq_scale;
|
|
};
|
|
|
|
static int systick_set_oneshot(struct clock_event_device *evt);
|
|
static int systick_shutdown(struct clock_event_device *evt);
|
|
|
|
static int systick_next_event(unsigned long delta,
|
|
struct clock_event_device *evt)
|
|
{
|
|
struct systick_device *sdev;
|
|
u32 count;
|
|
|
|
sdev = container_of(evt, struct systick_device, dev);
|
|
count = ioread32(sdev->membase + SYSTICK_COUNT);
|
|
count = (count + delta) % SYSTICK_FREQ;
|
|
iowrite32(count, sdev->membase + SYSTICK_COMPARE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void systick_event_handler(struct clock_event_device *dev)
|
|
{
|
|
/* noting to do here */
|
|
}
|
|
|
|
static irqreturn_t systick_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct clock_event_device *dev = (struct clock_event_device *)dev_id;
|
|
|
|
dev->event_handler(dev);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct systick_device systick = {
|
|
.dev = {
|
|
/*
|
|
* cevt-r4k uses 300, make sure systick
|
|
* gets used if available
|
|
*/
|
|
.rating = 310,
|
|
.features = CLOCK_EVT_FEAT_ONESHOT,
|
|
.set_next_event = systick_next_event,
|
|
.set_state_shutdown = systick_shutdown,
|
|
.set_state_oneshot = systick_set_oneshot,
|
|
.event_handler = systick_event_handler,
|
|
},
|
|
};
|
|
|
|
static int systick_shutdown(struct clock_event_device *evt)
|
|
{
|
|
struct systick_device *sdev;
|
|
|
|
sdev = container_of(evt, struct systick_device, dev);
|
|
|
|
if (sdev->irq_requested)
|
|
free_irq(systick.dev.irq, &systick.dev);
|
|
sdev->irq_requested = 0;
|
|
iowrite32(0, systick.membase + SYSTICK_CONFIG);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int systick_set_oneshot(struct clock_event_device *evt)
|
|
{
|
|
const char *name = systick.dev.name;
|
|
struct systick_device *sdev;
|
|
int irq = systick.dev.irq;
|
|
|
|
sdev = container_of(evt, struct systick_device, dev);
|
|
|
|
if (!sdev->irq_requested) {
|
|
if (request_irq(irq, systick_interrupt,
|
|
IRQF_PERCPU | IRQF_TIMER, name, &systick.dev))
|
|
pr_err("Failed to request irq %d (%s)\n", irq, name);
|
|
}
|
|
sdev->irq_requested = 1;
|
|
iowrite32(CFG_EXT_STK_EN | CFG_CNT_EN,
|
|
systick.membase + SYSTICK_CONFIG);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init ralink_systick_init(struct device_node *np)
|
|
{
|
|
int ret;
|
|
|
|
systick.membase = of_iomap(np, 0);
|
|
if (!systick.membase)
|
|
return -ENXIO;
|
|
|
|
systick.dev.name = np->name;
|
|
clockevents_calc_mult_shift(&systick.dev, SYSTICK_FREQ, 60);
|
|
systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
|
|
systick.dev.max_delta_ticks = 0x7fff;
|
|
systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
|
|
systick.dev.min_delta_ticks = 0x3;
|
|
systick.dev.irq = irq_of_parse_and_map(np, 0);
|
|
if (!systick.dev.irq) {
|
|
pr_err("%pOFn: request_irq failed", np);
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
|
|
SYSTICK_FREQ, 301, 16,
|
|
clocksource_mmio_readl_up);
|
|
if (ret)
|
|
return ret;
|
|
|
|
clockevents_register_device(&systick.dev);
|
|
|
|
pr_info("%pOFn: running - mult: %d, shift: %d\n",
|
|
np, systick.dev.mult, systick.dev.shift);
|
|
|
|
return 0;
|
|
}
|
|
|
|
TIMER_OF_DECLARE(systick, "ralink,cevt-systick", ralink_systick_init);
|