arch/arm/plat-samsung/irq-vic-timer.c

   1 /* arch/arm/plat-samsung/irq-vic-timer.c
   2  *      originally part of arch/arm/plat-s3c64xx/irq.c
   3  *
   4  * Copyright 2008 Openmoko, Inc.
   5  * Copyright 2008 Simtec Electronics
   6  *      Ben Dooks <ben@simtec.co.uk>
   7  *      http://armlinux.simtec.co.uk/
   8  *
   9  * S3C64XX - Interrupt handling
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/irq.h>
  19 #include <linux/io.h>
  20
  21 #include <mach/map.h>
  22 #include <plat/irq-vic-timer.h>
  23 #include <plat/regs-timer.h>
  24
  25 static void s3c_irq_demux_vic_timer(unsigned int irq, struct irq_desc *desc)
  26 {
  27         generic_handle_irq((int)desc->irq_data.handler_data);
  28 }
  29
  30 /* We assume the IRQ_TIMER0..IRQ_TIMER4 range is continuous. */
  31 static void s3c_irq_timer_ack(struct irq_data *d)
  32 {
  33         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  34         u32 mask = (1 << 5) << (d->irq - gc->irq_base);
  35
  36         irq_reg_writel(mask | gc->mask_cache, gc->reg_base);
  37 }
  38
  39 /**
  40  * s3c_init_vic_timer_irq() - initialise timer irq chanined off VIC.\
  41  * @num: Number of timers to initialize
  42  * @timer_irq: Base IRQ number to be used for the timers.
  43  *
  44  * Register the necessary IRQ chaining and support for the timer IRQs
  45  * chained of the VIC.
  46  */
  47 void __init s3c_init_vic_timer_irq(unsigned int num, unsigned int timer_irq)
  48 {
  49         unsigned int pirq[5] = { IRQ_TIMER0_VIC, IRQ_TIMER1_VIC, IRQ_TIMER2_VIC,
  50                                  IRQ_TIMER3_VIC, IRQ_TIMER4_VIC };
  51         struct irq_chip_generic *s3c_tgc;
  52         struct irq_chip_type *ct;
  53         unsigned int i;
  54
  55         s3c_tgc = irq_alloc_generic_chip("s3c-timer", 1, timer_irq,
  56                                          S3C64XX_TINT_CSTAT, handle_level_irq);
  57
  58         if (!s3c_tgc) {
  59                 pr_err("%s: irq_alloc_generic_chip for IRQ %d failed\n",
  60                        __func__, timer_irq);
  61                 return;
  62         }
  63
  64         ct = s3c_tgc->chip_types;
  65         ct->chip.irq_mask = irq_gc_mask_clr_bit;
  66         ct->chip.irq_unmask = irq_gc_mask_set_bit;
  67         ct->chip.irq_ack = s3c_irq_timer_ack;
  68         irq_setup_generic_chip(s3c_tgc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
  69                                IRQ_NOREQUEST | IRQ_NOPROBE, 0);
  70         /* Clear the upper bits of the mask_cache*/
  71         s3c_tgc->mask_cache &= 0x1f;
  72
  73         for (i = 0; i < num; i++, timer_irq++) {
  74                 irq_set_chained_handler(pirq[i], s3c_irq_demux_vic_timer);
  75                 irq_set_handler_data(pirq[i], (void *)timer_irq);
  76         }
  77 }