arch/mips/kernel/cevt-txx9.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Based on linux/arch/mips/kernel/cevt-r4k.c,
   7  *          linux/arch/mips/jmr3927/rbhma3100/setup.c
   8  *
   9  * Copyright 2001 MontaVista Software Inc.
  10  * Copyright (C) 2000-2001 Toshiba Corporation
  11  * Copyright (C) 2007 MIPS Technologies, Inc.
  12  * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
  13  */
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <asm/time.h>
  18 #include <asm/txx9tmr.h>
  19
  20 #define TCR_BASE (TXx9_TMTCR_CCDE | TXx9_TMTCR_CRE | TXx9_TMTCR_TMODE_ITVL)
  21 #define TIMER_CCD       0       /* 1/2 */
  22 #define TIMER_CLK(imclk)        ((imclk) / (2 << TIMER_CCD))
  23
  24 struct txx9_clocksource {
  25         struct clocksource cs;
  26         struct txx9_tmr_reg __iomem *tmrptr;
  27 };
  28
  29 static cycle_t txx9_cs_read(struct clocksource *cs)
  30 {
  31         struct txx9_clocksource *txx9_cs =
  32                 container_of(cs, struct txx9_clocksource, cs);
  33         return __raw_readl(&txx9_cs->tmrptr->trr);
  34 }
  35
  36 /* Use 1 bit smaller width to use full bits in that width */
  37 #define TXX9_CLOCKSOURCE_BITS (TXX9_TIMER_BITS - 1)
  38
  39 static struct txx9_clocksource txx9_clocksource = {
  40         .cs = {
  41                 .name           = "TXx9",
  42                 .rating         = 200,
  43                 .read           = txx9_cs_read,
  44                 .mask           = CLOCKSOURCE_MASK(TXX9_CLOCKSOURCE_BITS),
  45                 .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
  46         },
  47 };
  48
  49 void __init txx9_clocksource_init(unsigned long baseaddr,
  50                                   unsigned int imbusclk)
  51 {
  52         struct txx9_tmr_reg __iomem *tmrptr;
  53
  54         clocksource_register_hz(&txx9_clocksource.cs, TIMER_CLK(imbusclk));
  55
  56         tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
  57         __raw_writel(TCR_BASE, &tmrptr->tcr);
  58         __raw_writel(0, &tmrptr->tisr);
  59         __raw_writel(TIMER_CCD, &tmrptr->ccdr);
  60         __raw_writel(TXx9_TMITMR_TZCE, &tmrptr->itmr);
  61         __raw_writel(1 << TXX9_CLOCKSOURCE_BITS, &tmrptr->cpra);
  62         __raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
  63         txx9_clocksource.tmrptr = tmrptr;
  64 }
  65
  66 struct txx9_clock_event_device {
  67         struct clock_event_device cd;
  68         struct txx9_tmr_reg __iomem *tmrptr;
  69 };
  70
  71 static void txx9tmr_stop_and_clear(struct txx9_tmr_reg __iomem *tmrptr)
  72 {
  73         /* stop and reset counter */
  74         __raw_writel(TCR_BASE, &tmrptr->tcr);
  75         /* clear pending interrupt */
  76         __raw_writel(0, &tmrptr->tisr);
  77 }
  78
  79 static void txx9tmr_set_mode(enum clock_event_mode mode,
  80                              struct clock_event_device *evt)
  81 {
  82         struct txx9_clock_event_device *txx9_cd =
  83                 container_of(evt, struct txx9_clock_event_device, cd);
  84         struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
  85
  86         txx9tmr_stop_and_clear(tmrptr);
  87         switch (mode) {
  88         case CLOCK_EVT_MODE_PERIODIC:
  89                 __raw_writel(TXx9_TMITMR_TIIE | TXx9_TMITMR_TZCE,
  90                              &tmrptr->itmr);
  91                 /* start timer */
  92                 __raw_writel(((u64)(NSEC_PER_SEC / HZ) * evt->mult) >>
  93                              evt->shift,
  94                              &tmrptr->cpra);
  95                 __raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
  96                 break;
  97         case CLOCK_EVT_MODE_SHUTDOWN:
  98         case CLOCK_EVT_MODE_UNUSED:
  99                 __raw_writel(0, &tmrptr->itmr);
 100                 break;
 101         case CLOCK_EVT_MODE_ONESHOT:
 102                 __raw_writel(TXx9_TMITMR_TIIE, &tmrptr->itmr);
 103                 break;
 104         case CLOCK_EVT_MODE_RESUME:
 105                 __raw_writel(TIMER_CCD, &tmrptr->ccdr);
 106                 __raw_writel(0, &tmrptr->itmr);
 107                 break;
 108         }
 109 }
 110
 111 static int txx9tmr_set_next_event(unsigned long delta,
 112                                   struct clock_event_device *evt)
 113 {
 114         struct txx9_clock_event_device *txx9_cd =
 115                 container_of(evt, struct txx9_clock_event_device, cd);
 116         struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
 117
 118         txx9tmr_stop_and_clear(tmrptr);
 119         /* start timer */
 120         __raw_writel(delta, &tmrptr->cpra);
 121         __raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
 122         return 0;
 123 }
 124
 125 static struct txx9_clock_event_device txx9_clock_event_device = {
 126         .cd = {
 127                 .name           = "TXx9",
 128                 .features       = CLOCK_EVT_FEAT_PERIODIC |
 129                                   CLOCK_EVT_FEAT_ONESHOT,
 130                 .rating         = 200,
 131                 .set_mode       = txx9tmr_set_mode,
 132                 .set_next_event = txx9tmr_set_next_event,
 133         },
 134 };
 135
 136 static irqreturn_t txx9tmr_interrupt(int irq, void *dev_id)
 137 {
 138         struct txx9_clock_event_device *txx9_cd = dev_id;
 139         struct clock_event_device *cd = &txx9_cd->cd;
 140         struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
 141
 142         __raw_writel(0, &tmrptr->tisr); /* ack interrupt */
 143         cd->event_handler(cd);
 144         return IRQ_HANDLED;
 145 }
 146
 147 static struct irqaction txx9tmr_irq = {
 148         .handler        = txx9tmr_interrupt,
 149         .flags          = IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER,
 150         .name           = "txx9tmr",
 151         .dev_id         = &txx9_clock_event_device,
 152 };
 153
 154 void __init txx9_clockevent_init(unsigned long baseaddr, int irq,
 155                                  unsigned int imbusclk)
 156 {
 157         struct clock_event_device *cd = &txx9_clock_event_device.cd;
 158         struct txx9_tmr_reg __iomem *tmrptr;
 159
 160         tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
 161         txx9tmr_stop_and_clear(tmrptr);
 162         __raw_writel(TIMER_CCD, &tmrptr->ccdr);
 163         __raw_writel(0, &tmrptr->itmr);
 164         txx9_clock_event_device.tmrptr = tmrptr;
 165
 166         clockevent_set_clock(cd, TIMER_CLK(imbusclk));
 167         cd->max_delta_ns =
 168                 clockevent_delta2ns(0xffffffff >> (32 - TXX9_TIMER_BITS), cd);
 169         cd->min_delta_ns = clockevent_delta2ns(0xf, cd);
 170         cd->irq = irq;
 171         cd->cpumask = cpumask_of(0),
 172         clockevents_register_device(cd);
 173         setup_irq(irq, &txx9tmr_irq);
 174         printk(KERN_INFO "TXx9: clockevent device at 0x%lx, irq %d\n",
 175                baseaddr, irq);
 176 }
 177
 178 void __init txx9_tmr_init(unsigned long baseaddr)
 179 {
 180         struct txx9_tmr_reg __iomem *tmrptr;
 181
 182         tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
 183         /* Start once to make CounterResetEnable effective */
 184         __raw_writel(TXx9_TMTCR_CRE | TXx9_TMTCR_TCE, &tmrptr->tcr);
 185         /* Stop and reset the counter */
 186         __raw_writel(TXx9_TMTCR_CRE, &tmrptr->tcr);
 187         __raw_writel(0, &tmrptr->tisr);
 188         __raw_writel(0xffffffff, &tmrptr->cpra);
 189         __raw_writel(0, &tmrptr->itmr);
 190         __raw_writel(0, &tmrptr->ccdr);
 191         __raw_writel(0, &tmrptr->pgmr);
 192         iounmap(tmrptr);
 193 }