+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/arch/cris/arch-v32/kernel/time.c
- *
- * Copyright (C) 2003-2010 Axis Communications AB
- *
- */
-
-#include <linux/timex.h>
-#include <linux/time.h>
-#include <linux/clocksource.h>
-#include <linux/clockchips.h>
-#include <linux/interrupt.h>
-#include <linux/swap.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/threads.h>
-#include <linux/cpufreq.h>
-#include <linux/sched_clock.h>
-#include <linux/mm.h>
-#include <asm/types.h>
-#include <asm/signal.h>
-#include <asm/io.h>
-#include <asm/delay.h>
-#include <asm/irq.h>
-#include <asm/irq_regs.h>
-
-#include <hwregs/reg_map.h>
-#include <hwregs/reg_rdwr.h>
-#include <hwregs/timer_defs.h>
-#include <hwregs/intr_vect_defs.h>
-#ifdef CONFIG_CRIS_MACH_ARTPEC3
-#include <hwregs/clkgen_defs.h>
-#endif
-
-/* Watchdog defines */
-#define ETRAX_WD_KEY_MASK 0x7F /* key is 7 bit */
-#define ETRAX_WD_HZ 763 /* watchdog counts at 763 Hz */
-/* Number of 763 counts before watchdog bites */
-#define ETRAX_WD_CNT ((2*ETRAX_WD_HZ)/HZ + 1)
-
-#define CRISV32_TIMER_FREQ (100000000lu)
-
-unsigned long timer_regs[NR_CPUS] =
-{
- regi_timer0,
-};
-
-extern int set_rtc_mmss(unsigned long nowtime);
-
-#ifdef CONFIG_CPU_FREQ
-static int cris_time_freq_notifier(struct notifier_block *nb,
- unsigned long val, void *data);
-
-static struct notifier_block cris_time_freq_notifier_block = {
- .notifier_call = cris_time_freq_notifier,
-};
-#endif
-
-unsigned long get_ns_in_jiffie(void)
-{
- reg_timer_r_tmr0_data data;
- unsigned long ns;
-
- data = REG_RD(timer, regi_timer0, r_tmr0_data);
- ns = (TIMER0_DIV - data) * 10;
- return ns;
-}
-
-/* From timer MDS describing the hardware watchdog:
- * 4.3.1 Watchdog Operation
- * The watchdog timer is an 8-bit timer with a configurable start value.
- * Once started the watchdog counts downwards with a frequency of 763 Hz
- * (100/131072 MHz). When the watchdog counts down to 1, it generates an
- * NMI (Non Maskable Interrupt), and when it counts down to 0, it resets the
- * chip.
- */
-/* This gives us 1.3 ms to do something useful when the NMI comes */
-
-/* Right now, starting the watchdog is the same as resetting it */
-#define start_watchdog reset_watchdog
-
-#if defined(CONFIG_ETRAX_WATCHDOG)
-static short int watchdog_key = 42; /* arbitrary 7 bit number */
-#endif
-
-/* Number of pages to consider "out of memory". It is normal that the memory
- * is used though, so set this really low. */
-#define WATCHDOG_MIN_FREE_PAGES 8
-
-#if defined(CONFIG_ETRAX_WATCHDOG_NICE_DOGGY)
-/* for reliable NICE_DOGGY behaviour */
-static int bite_in_progress;
-#endif
-
-void reset_watchdog(void)
-{
-#if defined(CONFIG_ETRAX_WATCHDOG)
- reg_timer_rw_wd_ctrl wd_ctrl = { 0 };
-
-#if defined(CONFIG_ETRAX_WATCHDOG_NICE_DOGGY)
- if (unlikely(bite_in_progress))
- return;
-#endif
- /* Only keep watchdog happy as long as we have memory left! */
- if(nr_free_pages() > WATCHDOG_MIN_FREE_PAGES) {
- /* Reset the watchdog with the inverse of the old key */
- /* Invert key, which is 7 bits */
- watchdog_key ^= ETRAX_WD_KEY_MASK;
- wd_ctrl.cnt = ETRAX_WD_CNT;
- wd_ctrl.cmd = regk_timer_start;
- wd_ctrl.key = watchdog_key;
- REG_WR(timer, regi_timer0, rw_wd_ctrl, wd_ctrl);
- }
-#endif
-}
-
-/* stop the watchdog - we still need the correct key */
-
-void stop_watchdog(void)
-{
-#if defined(CONFIG_ETRAX_WATCHDOG)
- reg_timer_rw_wd_ctrl wd_ctrl = { 0 };
- watchdog_key ^= ETRAX_WD_KEY_MASK; /* invert key, which is 7 bits */
- wd_ctrl.cnt = ETRAX_WD_CNT;
- wd_ctrl.cmd = regk_timer_stop;
- wd_ctrl.key = watchdog_key;
- REG_WR(timer, regi_timer0, rw_wd_ctrl, wd_ctrl);
-#endif
-}
-
-extern void show_registers(struct pt_regs *regs);
-
-void handle_watchdog_bite(struct pt_regs *regs)
-{
-#if defined(CONFIG_ETRAX_WATCHDOG)
- extern int cause_of_death;
-
- nmi_enter();
- oops_in_progress = 1;
-#if defined(CONFIG_ETRAX_WATCHDOG_NICE_DOGGY)
- bite_in_progress = 1;
-#endif
- printk(KERN_WARNING "Watchdog bite\n");
-
- /* Check if forced restart or unexpected watchdog */
- if (cause_of_death == 0xbedead) {
-#ifdef CONFIG_CRIS_MACH_ARTPEC3
- /* There is a bug in Artpec-3 (voodoo TR 78) that requires
- * us to go to lower frequency for the reset to be reliable
- */
- reg_clkgen_rw_clk_ctrl ctrl =
- REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
- ctrl.pll = 0;
- REG_WR(clkgen, regi_clkgen, rw_clk_ctrl, ctrl);
-#endif
- while(1);
- }
-
- /* Unexpected watchdog, stop the watchdog and dump registers. */
- stop_watchdog();
- printk(KERN_WARNING "Oops: bitten by watchdog\n");
- show_registers(regs);
- oops_in_progress = 0;
- printk("\n"); /* Flush mtdoops. */
-#ifndef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
- reset_watchdog();
-#endif
- while(1) /* nothing */;
-#endif
-}
-
-extern void cris_profile_sample(struct pt_regs *regs);
-static void __iomem *timer_base;
-
-static int crisv32_clkevt_switch_state(struct clock_event_device *dev)
-{
- reg_timer_rw_tmr0_ctrl ctrl = {
- .op = regk_timer_hold,
- .freq = regk_timer_f100,
- };
-
- REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl);
- return 0;
-}
-
-static int crisv32_clkevt_next_event(unsigned long evt,
- struct clock_event_device *dev)
-{
- reg_timer_rw_tmr0_ctrl ctrl = {
- .op = regk_timer_ld,
- .freq = regk_timer_f100,
- };
-
- REG_WR(timer, timer_base, rw_tmr0_div, evt);
- REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl);
-
- ctrl.op = regk_timer_run;
- REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl);
-
- return 0;
-}
-
-static irqreturn_t crisv32_timer_interrupt(int irq, void *dev_id)
-{
- struct clock_event_device *evt = dev_id;
- reg_timer_rw_tmr0_ctrl ctrl = {
- .op = regk_timer_hold,
- .freq = regk_timer_f100,
- };
- reg_timer_rw_ack_intr ack = { .tmr0 = 1 };
- reg_timer_r_masked_intr intr;
-
- intr = REG_RD(timer, timer_base, r_masked_intr);
- if (!intr.tmr0)
- return IRQ_NONE;
-
- REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl);
- REG_WR(timer, timer_base, rw_ack_intr, ack);
-
- reset_watchdog();
-#ifdef CONFIG_SYSTEM_PROFILER
- cris_profile_sample(get_irq_regs());
-#endif
-
- evt->event_handler(evt);
-
- return IRQ_HANDLED;
-}
-
-static struct clock_event_device crisv32_clockevent = {
- .name = "crisv32-timer",
- .rating = 300,
- .features = CLOCK_EVT_FEAT_ONESHOT,
- .set_state_oneshot = crisv32_clkevt_switch_state,
- .set_state_shutdown = crisv32_clkevt_switch_state,
- .tick_resume = crisv32_clkevt_switch_state,
- .set_next_event = crisv32_clkevt_next_event,
-};
-
-/* Timer is IRQF_SHARED so drivers can add stuff to the timer irq chain. */
-static struct irqaction irq_timer = {
- .handler = crisv32_timer_interrupt,
- .flags = IRQF_TIMER | IRQF_SHARED,
- .name = "crisv32-timer",
- .dev_id = &crisv32_clockevent,
-};
-
-static u64 notrace crisv32_timer_sched_clock(void)
-{
- return REG_RD(timer, timer_base, r_time);
-}
-
-static void __init crisv32_timer_init(void)
-{
- reg_timer_rw_intr_mask timer_intr_mask;
- reg_timer_rw_tmr0_ctrl ctrl = {
- .op = regk_timer_hold,
- .freq = regk_timer_f100,
- };
-
- REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl);
-
- timer_intr_mask = REG_RD(timer, timer_base, rw_intr_mask);
- timer_intr_mask.tmr0 = 1;
- REG_WR(timer, timer_base, rw_intr_mask, timer_intr_mask);
-}
-
-void __init time_init(void)
-{
- int irq;
- int ret;
-
- /* Probe for the RTC and read it if it exists.
- * Before the RTC can be probed the loops_per_usec variable needs
- * to be initialized to make usleep work. A better value for
- * loops_per_usec is calculated by the kernel later once the
- * clock has started.
- */
- loops_per_usec = 50;
-
- irq = TIMER0_INTR_VECT;
- timer_base = (void __iomem *) regi_timer0;
-
- crisv32_timer_init();
-
- sched_clock_register(crisv32_timer_sched_clock, 32,
- CRISV32_TIMER_FREQ);
-
- clocksource_mmio_init(timer_base + REG_RD_ADDR_timer_r_time,
- "crisv32-timer", CRISV32_TIMER_FREQ,
- 300, 32, clocksource_mmio_readl_up);
-
- crisv32_clockevent.cpumask = cpu_possible_mask;
- crisv32_clockevent.irq = irq;
-
- ret = setup_irq(irq, &irq_timer);
- if (ret)
- pr_warn("failed to setup irq %d\n", irq);
-
- clockevents_config_and_register(&crisv32_clockevent,
- CRISV32_TIMER_FREQ,
- 2, 0xffffffff);
-
- /* Enable watchdog if we should use one. */
-
-#if defined(CONFIG_ETRAX_WATCHDOG)
- printk(KERN_INFO "Enabling watchdog...\n");
- start_watchdog();
-
- /* If we use the hardware watchdog, we want to trap it as an NMI
- * and dump registers before it resets us. For this to happen, we
- * must set the "m" NMI enable flag (which once set, is unset only
- * when an NMI is taken). */
- {
- unsigned long flags;
- local_save_flags(flags);
- flags |= (1<<30); /* NMI M flag is at bit 30 */
- local_irq_restore(flags);
- }
-#endif
-
-#ifdef CONFIG_CPU_FREQ
- cpufreq_register_notifier(&cris_time_freq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
-#endif
-}
-
-#ifdef CONFIG_CPU_FREQ
-static int cris_time_freq_notifier(struct notifier_block *nb,
- unsigned long val, void *data)
-{
- struct cpufreq_freqs *freqs = data;
- if (val == CPUFREQ_POSTCHANGE) {
- reg_timer_r_tmr0_data data;
- reg_timer_rw_tmr0_div div = (freqs->new * 500) / HZ;
- do {
- data = REG_RD(timer, timer_regs[freqs->cpu],
- r_tmr0_data);
- } while (data > 20);
- REG_WR(timer, timer_regs[freqs->cpu], rw_tmr0_div, div);
- }
- return 0;
-}
-#endif
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