forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
213 lines
5.5 KiB
213 lines
5.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* linux/drivers/clocksource/zevio-timer.c |
|
* |
|
* Copyright (C) 2013 Daniel Tang <[email protected]> |
|
*/ |
|
|
|
#include <linux/io.h> |
|
#include <linux/irq.h> |
|
#include <linux/of.h> |
|
#include <linux/of_address.h> |
|
#include <linux/of_irq.h> |
|
#include <linux/clk.h> |
|
#include <linux/clockchips.h> |
|
#include <linux/cpumask.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/slab.h> |
|
|
|
#define IO_CURRENT_VAL 0x00 |
|
#define IO_DIVIDER 0x04 |
|
#define IO_CONTROL 0x08 |
|
|
|
#define IO_TIMER1 0x00 |
|
#define IO_TIMER2 0x0C |
|
|
|
#define IO_MATCH_BEGIN 0x18 |
|
#define IO_MATCH(x) (IO_MATCH_BEGIN + ((x) << 2)) |
|
|
|
#define IO_INTR_STS 0x00 |
|
#define IO_INTR_ACK 0x00 |
|
#define IO_INTR_MSK 0x04 |
|
|
|
#define CNTL_STOP_TIMER (1 << 4) |
|
#define CNTL_RUN_TIMER (0 << 4) |
|
|
|
#define CNTL_INC (1 << 3) |
|
#define CNTL_DEC (0 << 3) |
|
|
|
#define CNTL_TOZERO 0 |
|
#define CNTL_MATCH(x) ((x) + 1) |
|
#define CNTL_FOREVER 7 |
|
|
|
/* There are 6 match registers but we only use one. */ |
|
#define TIMER_MATCH 0 |
|
|
|
#define TIMER_INTR_MSK (1 << (TIMER_MATCH)) |
|
#define TIMER_INTR_ALL 0x3F |
|
|
|
struct zevio_timer { |
|
void __iomem *base; |
|
void __iomem *timer1, *timer2; |
|
void __iomem *interrupt_regs; |
|
|
|
struct clk *clk; |
|
struct clock_event_device clkevt; |
|
|
|
char clocksource_name[64]; |
|
char clockevent_name[64]; |
|
}; |
|
|
|
static int zevio_timer_set_event(unsigned long delta, |
|
struct clock_event_device *dev) |
|
{ |
|
struct zevio_timer *timer = container_of(dev, struct zevio_timer, |
|
clkevt); |
|
|
|
writel(delta, timer->timer1 + IO_CURRENT_VAL); |
|
writel(CNTL_RUN_TIMER | CNTL_DEC | CNTL_MATCH(TIMER_MATCH), |
|
timer->timer1 + IO_CONTROL); |
|
|
|
return 0; |
|
} |
|
|
|
static int zevio_timer_shutdown(struct clock_event_device *dev) |
|
{ |
|
struct zevio_timer *timer = container_of(dev, struct zevio_timer, |
|
clkevt); |
|
|
|
/* Disable timer interrupts */ |
|
writel(0, timer->interrupt_regs + IO_INTR_MSK); |
|
writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK); |
|
/* Stop timer */ |
|
writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL); |
|
return 0; |
|
} |
|
|
|
static int zevio_timer_set_oneshot(struct clock_event_device *dev) |
|
{ |
|
struct zevio_timer *timer = container_of(dev, struct zevio_timer, |
|
clkevt); |
|
|
|
/* Enable timer interrupts */ |
|
writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_MSK); |
|
writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK); |
|
return 0; |
|
} |
|
|
|
static irqreturn_t zevio_timer_interrupt(int irq, void *dev_id) |
|
{ |
|
struct zevio_timer *timer = dev_id; |
|
u32 intr; |
|
|
|
intr = readl(timer->interrupt_regs + IO_INTR_ACK); |
|
if (!(intr & TIMER_INTR_MSK)) |
|
return IRQ_NONE; |
|
|
|
writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_ACK); |
|
writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL); |
|
|
|
if (timer->clkevt.event_handler) |
|
timer->clkevt.event_handler(&timer->clkevt); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
static int __init zevio_timer_add(struct device_node *node) |
|
{ |
|
struct zevio_timer *timer; |
|
struct resource res; |
|
int irqnr, ret; |
|
|
|
timer = kzalloc(sizeof(*timer), GFP_KERNEL); |
|
if (!timer) |
|
return -ENOMEM; |
|
|
|
timer->base = of_iomap(node, 0); |
|
if (!timer->base) { |
|
ret = -EINVAL; |
|
goto error_free; |
|
} |
|
timer->timer1 = timer->base + IO_TIMER1; |
|
timer->timer2 = timer->base + IO_TIMER2; |
|
|
|
timer->clk = of_clk_get(node, 0); |
|
if (IS_ERR(timer->clk)) { |
|
ret = PTR_ERR(timer->clk); |
|
pr_err("Timer clock not found! (error %d)\n", ret); |
|
goto error_unmap; |
|
} |
|
|
|
timer->interrupt_regs = of_iomap(node, 1); |
|
irqnr = irq_of_parse_and_map(node, 0); |
|
|
|
of_address_to_resource(node, 0, &res); |
|
scnprintf(timer->clocksource_name, sizeof(timer->clocksource_name), |
|
"%llx.%pOFn_clocksource", |
|
(unsigned long long)res.start, node); |
|
|
|
scnprintf(timer->clockevent_name, sizeof(timer->clockevent_name), |
|
"%llx.%pOFn_clockevent", |
|
(unsigned long long)res.start, node); |
|
|
|
if (timer->interrupt_regs && irqnr) { |
|
timer->clkevt.name = timer->clockevent_name; |
|
timer->clkevt.set_next_event = zevio_timer_set_event; |
|
timer->clkevt.set_state_shutdown = zevio_timer_shutdown; |
|
timer->clkevt.set_state_oneshot = zevio_timer_set_oneshot; |
|
timer->clkevt.tick_resume = zevio_timer_set_oneshot; |
|
timer->clkevt.rating = 200; |
|
timer->clkevt.cpumask = cpu_possible_mask; |
|
timer->clkevt.features = CLOCK_EVT_FEAT_ONESHOT; |
|
timer->clkevt.irq = irqnr; |
|
|
|
writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL); |
|
writel(0, timer->timer1 + IO_DIVIDER); |
|
|
|
/* Start with timer interrupts disabled */ |
|
writel(0, timer->interrupt_regs + IO_INTR_MSK); |
|
writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK); |
|
|
|
/* Interrupt to occur when timer value matches 0 */ |
|
writel(0, timer->base + IO_MATCH(TIMER_MATCH)); |
|
|
|
if (request_irq(irqnr, zevio_timer_interrupt, |
|
IRQF_TIMER | IRQF_IRQPOLL, |
|
timer->clockevent_name, timer)) { |
|
pr_err("%s: request_irq() failed\n", |
|
timer->clockevent_name); |
|
} |
|
|
|
clockevents_config_and_register(&timer->clkevt, |
|
clk_get_rate(timer->clk), 0x0001, 0xffff); |
|
pr_info("Added %s as clockevent\n", timer->clockevent_name); |
|
} |
|
|
|
writel(CNTL_STOP_TIMER, timer->timer2 + IO_CONTROL); |
|
writel(0, timer->timer2 + IO_CURRENT_VAL); |
|
writel(0, timer->timer2 + IO_DIVIDER); |
|
writel(CNTL_RUN_TIMER | CNTL_FOREVER | CNTL_INC, |
|
timer->timer2 + IO_CONTROL); |
|
|
|
clocksource_mmio_init(timer->timer2 + IO_CURRENT_VAL, |
|
timer->clocksource_name, |
|
clk_get_rate(timer->clk), |
|
200, 16, |
|
clocksource_mmio_readw_up); |
|
|
|
pr_info("Added %s as clocksource\n", timer->clocksource_name); |
|
|
|
return 0; |
|
error_unmap: |
|
iounmap(timer->base); |
|
error_free: |
|
kfree(timer); |
|
return ret; |
|
} |
|
|
|
static int __init zevio_timer_init(struct device_node *node) |
|
{ |
|
return zevio_timer_add(node); |
|
} |
|
|
|
TIMER_OF_DECLARE(zevio_timer, "lsi,zevio-timer", zevio_timer_init);
|
|
|