arch/mips/kernel/cevt-gt641xx.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  GT641xx clockevent routines.
   4  *
   5  *  Copyright (C) 2007  Yoichi Yuasa <yuasa@linux-mips.org>
   6  */
   7 #include <linux/clockchips.h>
   8 #include <linux/init.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/irq.h>
  12
  13 #include <asm/gt64120.h>
  14 #include <asm/time.h>
  15
  16 static DEFINE_RAW_SPINLOCK(gt641xx_timer_lock);
  17 static unsigned int gt641xx_base_clock;
  18
  19 void gt641xx_set_base_clock(unsigned int clock)
  20 {
  21         gt641xx_base_clock = clock;
  22 }
  23
  24 int gt641xx_timer0_state(void)
  25 {
  26         if (GT_READ(GT_TC0_OFS))
  27                 return 0;
  28
  29         GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
  30         GT_WRITE(GT_TC_CONTROL_OFS, GT_TC_CONTROL_ENTC0_MSK);
  31
  32         return 1;
  33 }
  34
  35 static int gt641xx_timer0_set_next_event(unsigned long delta,
  36                                          struct clock_event_device *evt)
  37 {
  38         u32 ctrl;
  39
  40         raw_spin_lock(&gt641xx_timer_lock);
  41
  42         ctrl = GT_READ(GT_TC_CONTROL_OFS);
  43         ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
  44         ctrl |= GT_TC_CONTROL_ENTC0_MSK;
  45
  46         GT_WRITE(GT_TC0_OFS, delta);
  47         GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
  48
  49         raw_spin_unlock(&gt641xx_timer_lock);
  50
  51         return 0;
  52 }
  53
  54 static int gt641xx_timer0_shutdown(struct clock_event_device *evt)
  55 {
  56         u32 ctrl;
  57
  58         raw_spin_lock(&gt641xx_timer_lock);
  59
  60         ctrl = GT_READ(GT_TC_CONTROL_OFS);
  61         ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
  62         GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
  63
  64         raw_spin_unlock(&gt641xx_timer_lock);
  65         return 0;
  66 }
  67
  68 static int gt641xx_timer0_set_oneshot(struct clock_event_device *evt)
  69 {
  70         u32 ctrl;
  71
  72         raw_spin_lock(&gt641xx_timer_lock);
  73
  74         ctrl = GT_READ(GT_TC_CONTROL_OFS);
  75         ctrl &= ~GT_TC_CONTROL_SELTC0_MSK;
  76         ctrl |= GT_TC_CONTROL_ENTC0_MSK;
  77         GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
  78
  79         raw_spin_unlock(&gt641xx_timer_lock);
  80         return 0;
  81 }
  82
  83 static int gt641xx_timer0_set_periodic(struct clock_event_device *evt)
  84 {
  85         u32 ctrl;
  86
  87         raw_spin_lock(&gt641xx_timer_lock);
  88
  89         ctrl = GT_READ(GT_TC_CONTROL_OFS);
  90         ctrl |= GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK;
  91         GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
  92
  93         raw_spin_unlock(&gt641xx_timer_lock);
  94         return 0;
  95 }
  96
  97 static void gt641xx_timer0_event_handler(struct clock_event_device *dev)
  98 {
  99 }
 100
 101 static struct clock_event_device gt641xx_timer0_clockevent = {
 102         .name                   = "gt641xx-timer0",
 103         .features               = CLOCK_EVT_FEAT_PERIODIC |
 104                                   CLOCK_EVT_FEAT_ONESHOT,
 105         .irq                    = GT641XX_TIMER0_IRQ,
 106         .set_next_event         = gt641xx_timer0_set_next_event,
 107         .set_state_shutdown     = gt641xx_timer0_shutdown,
 108         .set_state_periodic     = gt641xx_timer0_set_periodic,
 109         .set_state_oneshot      = gt641xx_timer0_set_oneshot,
 110         .tick_resume            = gt641xx_timer0_shutdown,
 111         .event_handler          = gt641xx_timer0_event_handler,
 112 };
 113
 114 static irqreturn_t gt641xx_timer0_interrupt(int irq, void *dev_id)
 115 {
 116         struct clock_event_device *cd = &gt641xx_timer0_clockevent;
 117
 118         cd->event_handler(cd);
 119
 120         return IRQ_HANDLED;
 121 }
 122
 123 static int __init gt641xx_timer0_clockevent_init(void)
 124 {
 125         struct clock_event_device *cd;
 126
 127         if (!gt641xx_base_clock)
 128                 return 0;
 129
 130         GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
 131
 132         cd = &gt641xx_timer0_clockevent;
 133         cd->rating = 200 + gt641xx_base_clock / 10000000;
 134         clockevent_set_clock(cd, gt641xx_base_clock);
 135         cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
 136         cd->max_delta_ticks = 0x7fffffff;
 137         cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
 138         cd->min_delta_ticks = 0x300;
 139         cd->cpumask = cpumask_of(0);
 140
 141         clockevents_register_device(&gt641xx_timer0_clockevent);
 142
 143         return request_irq(GT641XX_TIMER0_IRQ, gt641xx_timer0_interrupt,
 144                            IRQF_PERCPU | IRQF_TIMER, "gt641xx_timer0", NULL);
 145 }
 146 arch_initcall(gt641xx_timer0_clockevent_init);