+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * System timer for CSR SiRFprimaII
- *
- * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
- */
-
-#include <linux/kernel.h>
-#include <linux/interrupt.h>
-#include <linux/clockchips.h>
-#include <linux/clocksource.h>
-#include <linux/bitops.h>
-#include <linux/irq.h>
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/slab.h>
-#include <linux/of.h>
-#include <linux/of_irq.h>
-#include <linux/of_address.h>
-#include <linux/sched_clock.h>
-
-#define PRIMA2_CLOCK_FREQ 1000000
-
-#define SIRFSOC_TIMER_COUNTER_LO 0x0000
-#define SIRFSOC_TIMER_COUNTER_HI 0x0004
-#define SIRFSOC_TIMER_MATCH_0 0x0008
-#define SIRFSOC_TIMER_MATCH_1 0x000C
-#define SIRFSOC_TIMER_MATCH_2 0x0010
-#define SIRFSOC_TIMER_MATCH_3 0x0014
-#define SIRFSOC_TIMER_MATCH_4 0x0018
-#define SIRFSOC_TIMER_MATCH_5 0x001C
-#define SIRFSOC_TIMER_STATUS 0x0020
-#define SIRFSOC_TIMER_INT_EN 0x0024
-#define SIRFSOC_TIMER_WATCHDOG_EN 0x0028
-#define SIRFSOC_TIMER_DIV 0x002C
-#define SIRFSOC_TIMER_LATCH 0x0030
-#define SIRFSOC_TIMER_LATCHED_LO 0x0034
-#define SIRFSOC_TIMER_LATCHED_HI 0x0038
-
-#define SIRFSOC_TIMER_WDT_INDEX 5
-
-#define SIRFSOC_TIMER_LATCH_BIT BIT(0)
-
-#define SIRFSOC_TIMER_REG_CNT 11
-
-static const u32 sirfsoc_timer_reg_list[SIRFSOC_TIMER_REG_CNT] = {
- SIRFSOC_TIMER_MATCH_0, SIRFSOC_TIMER_MATCH_1, SIRFSOC_TIMER_MATCH_2,
- SIRFSOC_TIMER_MATCH_3, SIRFSOC_TIMER_MATCH_4, SIRFSOC_TIMER_MATCH_5,
- SIRFSOC_TIMER_INT_EN, SIRFSOC_TIMER_WATCHDOG_EN, SIRFSOC_TIMER_DIV,
- SIRFSOC_TIMER_LATCHED_LO, SIRFSOC_TIMER_LATCHED_HI,
-};
-
-static u32 sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT];
-
-static void __iomem *sirfsoc_timer_base;
-
-/* timer0 interrupt handler */
-static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id)
-{
- struct clock_event_device *ce = dev_id;
-
- WARN_ON(!(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_STATUS) &
- BIT(0)));
-
- /* clear timer0 interrupt */
- writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
-
- ce->event_handler(ce);
-
- return IRQ_HANDLED;
-}
-
-/* read 64-bit timer counter */
-static u64 notrace sirfsoc_timer_read(struct clocksource *cs)
-{
- u64 cycles;
-
- /* latch the 64-bit timer counter */
- writel_relaxed(SIRFSOC_TIMER_LATCH_BIT,
- sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
- cycles = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_HI);
- cycles = (cycles << 32) |
- readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
-
- return cycles;
-}
-
-static int sirfsoc_timer_set_next_event(unsigned long delta,
- struct clock_event_device *ce)
-{
- unsigned long now, next;
-
- writel_relaxed(SIRFSOC_TIMER_LATCH_BIT,
- sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
- now = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
- next = now + delta;
- writel_relaxed(next, sirfsoc_timer_base + SIRFSOC_TIMER_MATCH_0);
- writel_relaxed(SIRFSOC_TIMER_LATCH_BIT,
- sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
- now = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
-
- return next - now > delta ? -ETIME : 0;
-}
-
-static int sirfsoc_timer_shutdown(struct clock_event_device *evt)
-{
- u32 val = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
-
- writel_relaxed(val & ~BIT(0),
- sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
- return 0;
-}
-
-static int sirfsoc_timer_set_oneshot(struct clock_event_device *evt)
-{
- u32 val = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
-
- writel_relaxed(val | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
- return 0;
-}
-
-static void sirfsoc_clocksource_suspend(struct clocksource *cs)
-{
- int i;
-
- writel_relaxed(SIRFSOC_TIMER_LATCH_BIT,
- sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
-
- for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
- sirfsoc_timer_reg_val[i] =
- readl_relaxed(sirfsoc_timer_base +
- sirfsoc_timer_reg_list[i]);
-}
-
-static void sirfsoc_clocksource_resume(struct clocksource *cs)
-{
- int i;
-
- for (i = 0; i < SIRFSOC_TIMER_REG_CNT - 2; i++)
- writel_relaxed(sirfsoc_timer_reg_val[i],
- sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
-
- writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 2],
- sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
- writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 1],
- sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
-}
-
-static struct clock_event_device sirfsoc_clockevent = {
- .name = "sirfsoc_clockevent",
- .rating = 200,
- .features = CLOCK_EVT_FEAT_ONESHOT,
- .set_state_shutdown = sirfsoc_timer_shutdown,
- .set_state_oneshot = sirfsoc_timer_set_oneshot,
- .set_next_event = sirfsoc_timer_set_next_event,
-};
-
-static struct clocksource sirfsoc_clocksource = {
- .name = "sirfsoc_clocksource",
- .rating = 200,
- .mask = CLOCKSOURCE_MASK(64),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
- .read = sirfsoc_timer_read,
- .suspend = sirfsoc_clocksource_suspend,
- .resume = sirfsoc_clocksource_resume,
-};
-
-/* Overwrite weak default sched_clock with more precise one */
-static u64 notrace sirfsoc_read_sched_clock(void)
-{
- return sirfsoc_timer_read(NULL);
-}
-
-static void __init sirfsoc_clockevent_init(void)
-{
- sirfsoc_clockevent.cpumask = cpumask_of(0);
- clockevents_config_and_register(&sirfsoc_clockevent, PRIMA2_CLOCK_FREQ,
- 2, -2);
-}
-
-/* initialize the kernel jiffy timer source */
-static int __init sirfsoc_prima2_timer_init(struct device_node *np)
-{
- unsigned long rate;
- unsigned int irq;
- struct clk *clk;
- int ret;
-
- clk = of_clk_get(np, 0);
- if (IS_ERR(clk)) {
- pr_err("Failed to get clock\n");
- return PTR_ERR(clk);
- }
-
- ret = clk_prepare_enable(clk);
- if (ret) {
- pr_err("Failed to enable clock\n");
- return ret;
- }
-
- rate = clk_get_rate(clk);
-
- if (rate < PRIMA2_CLOCK_FREQ || rate % PRIMA2_CLOCK_FREQ) {
- pr_err("Invalid clock rate\n");
- return -EINVAL;
- }
-
- sirfsoc_timer_base = of_iomap(np, 0);
- if (!sirfsoc_timer_base) {
- pr_err("unable to map timer cpu registers\n");
- return -ENXIO;
- }
-
- irq = irq_of_parse_and_map(np, 0);
-
- writel_relaxed(rate / PRIMA2_CLOCK_FREQ / 2 - 1,
- sirfsoc_timer_base + SIRFSOC_TIMER_DIV);
- writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
- writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
- writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
-
- ret = clocksource_register_hz(&sirfsoc_clocksource, PRIMA2_CLOCK_FREQ);
- if (ret) {
- pr_err("Failed to register clocksource\n");
- return ret;
- }
-
- sched_clock_register(sirfsoc_read_sched_clock, 64, PRIMA2_CLOCK_FREQ);
-
- ret = request_irq(irq, sirfsoc_timer_interrupt, IRQF_TIMER,
- "sirfsoc_timer0", &sirfsoc_clockevent);
- if (ret) {
- pr_err("Failed to setup irq\n");
- return ret;
- }
-
- sirfsoc_clockevent_init();
-
- return 0;
-}
-TIMER_OF_DECLARE(sirfsoc_prima2_timer,
- "sirf,prima2-tick", sirfsoc_prima2_timer_init);
projects / platform / kernel / linux-starfive.git / commitdiff