linux/arch/mips/rb532/irq.c
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   1/*
   2 *  This program is free software; you can redistribute  it and/or modify it
   3 *  under  the terms of  the GNU General  Public License as published by the
   4 *  Free Software Foundation;  either version 2 of the  License, or (at your
   5 *  option) any later version.
   6 *
   7 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
   8 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
   9 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  10 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  11 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  12 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  13 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  14 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  15 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  16 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  17 *
  18 *  You should have received a copy of the  GNU General Public License along
  19 *  with this program; if not, write  to the Free Software Foundation, Inc.,
  20 *  675 Mass Ave, Cambridge, MA 02139, USA.
  21 *
  22 * Copyright 2002 MontaVista Software Inc.
  23 * Author: MontaVista Software, Inc.
  24 *              stevel@mvista.com or source@mvista.com
  25 */
  26
  27#include <linux/bitops.h>
  28#include <linux/errno.h>
  29#include <linux/init.h>
  30#include <linux/io.h>
  31#include <linux/kernel_stat.h>
  32#include <linux/signal.h>
  33#include <linux/sched.h>
  34#include <linux/types.h>
  35#include <linux/interrupt.h>
  36#include <linux/ioport.h>
  37#include <linux/timex.h>
  38#include <linux/random.h>
  39#include <linux/delay.h>
  40
  41#include <asm/bootinfo.h>
  42#include <asm/time.h>
  43#include <asm/mipsregs.h>
  44
  45#include <asm/mach-rc32434/irq.h>
  46#include <asm/mach-rc32434/gpio.h>
  47
  48struct intr_group {
  49        u32 mask;       /* mask of valid bits in pending/mask registers */
  50        volatile u32 *base_addr;
  51};
  52
  53#define RC32434_NR_IRQS  (GROUP4_IRQ_BASE + 32)
  54
  55#if (NR_IRQS < RC32434_NR_IRQS)
  56#error Too little irqs defined. Did you override <asm/irq.h> ?
  57#endif
  58
  59static const struct intr_group intr_group[NUM_INTR_GROUPS] = {
  60        {
  61                .mask   = 0x0000efff,
  62                .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 0 * IC_GROUP_OFFSET)},
  63        {
  64                .mask   = 0x00001fff,
  65                .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 1 * IC_GROUP_OFFSET)},
  66        {
  67                .mask   = 0x00000007,
  68                .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 2 * IC_GROUP_OFFSET)},
  69        {
  70                .mask   = 0x0003ffff,
  71                .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 3 * IC_GROUP_OFFSET)},
  72        {
  73                .mask   = 0xffffffff,
  74                .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 4 * IC_GROUP_OFFSET)}
  75};
  76
  77#define READ_PEND(base) (*(base))
  78#define READ_MASK(base) (*(base + 2))
  79#define WRITE_MASK(base, val) (*(base + 2) = (val))
  80
  81static inline int irq_to_group(unsigned int irq_nr)
  82{
  83        return (irq_nr - GROUP0_IRQ_BASE) >> 5;
  84}
  85
  86static inline int group_to_ip(unsigned int group)
  87{
  88        return group + 2;
  89}
  90
  91static inline void enable_local_irq(unsigned int ip)
  92{
  93        int ipnum = 0x100 << ip;
  94
  95        set_c0_status(ipnum);
  96}
  97
  98static inline void disable_local_irq(unsigned int ip)
  99{
 100        int ipnum = 0x100 << ip;
 101
 102        clear_c0_status(ipnum);
 103}
 104
 105static inline void ack_local_irq(unsigned int ip)
 106{
 107        int ipnum = 0x100 << ip;
 108
 109        clear_c0_cause(ipnum);
 110}
 111
 112static void rb532_enable_irq(struct irq_data *d)
 113{
 114        unsigned int group, intr_bit, irq_nr = d->irq;
 115        int ip = irq_nr - GROUP0_IRQ_BASE;
 116        volatile unsigned int *addr;
 117
 118        if (ip < 0)
 119                enable_local_irq(irq_nr);
 120        else {
 121                group = ip >> 5;
 122
 123                ip &= (1 << 5) - 1;
 124                intr_bit = 1 << ip;
 125
 126                enable_local_irq(group_to_ip(group));
 127
 128                addr = intr_group[group].base_addr;
 129                WRITE_MASK(addr, READ_MASK(addr) & ~intr_bit);
 130        }
 131}
 132
 133static void rb532_disable_irq(struct irq_data *d)
 134{
 135        unsigned int group, intr_bit, mask, irq_nr = d->irq;
 136        int ip = irq_nr - GROUP0_IRQ_BASE;
 137        volatile unsigned int *addr;
 138
 139        if (ip < 0) {
 140                disable_local_irq(irq_nr);
 141        } else {
 142                group = ip >> 5;
 143
 144                ip &= (1 << 5) - 1;
 145                intr_bit = 1 << ip;
 146                addr = intr_group[group].base_addr;
 147                mask = READ_MASK(addr);
 148                mask |= intr_bit;
 149                WRITE_MASK(addr, mask);
 150
 151                /* There is a maximum of 14 GPIO interrupts */
 152                if (group == GPIO_MAPPED_IRQ_GROUP && irq_nr <= (GROUP4_IRQ_BASE + 13))
 153                        rb532_gpio_set_istat(0, irq_nr - GPIO_MAPPED_IRQ_BASE);
 154
 155                /*
 156                 * if there are no more interrupts enabled in this
 157                 * group, disable corresponding IP
 158                 */
 159                if (mask == intr_group[group].mask)
 160                        disable_local_irq(group_to_ip(group));
 161        }
 162}
 163
 164static void rb532_mask_and_ack_irq(struct irq_data *d)
 165{
 166        rb532_disable_irq(d);
 167        ack_local_irq(group_to_ip(irq_to_group(d->irq)));
 168}
 169
 170static int rb532_set_type(struct irq_data *d,  unsigned type)
 171{
 172        int gpio = d->irq - GPIO_MAPPED_IRQ_BASE;
 173        int group = irq_to_group(d->irq);
 174
 175        if (group != GPIO_MAPPED_IRQ_GROUP || d->irq > (GROUP4_IRQ_BASE + 13))
 176                return (type == IRQ_TYPE_LEVEL_HIGH) ? 0 : -EINVAL;
 177
 178        switch (type) {
 179        case IRQ_TYPE_LEVEL_HIGH:
 180                rb532_gpio_set_ilevel(1, gpio);
 181                break;
 182        case IRQ_TYPE_LEVEL_LOW:
 183                rb532_gpio_set_ilevel(0, gpio);
 184                break;
 185        default:
 186                return -EINVAL;
 187        }
 188
 189        return 0;
 190}
 191
 192static struct irq_chip rc32434_irq_type = {
 193        .name           = "RB532",
 194        .irq_ack        = rb532_disable_irq,
 195        .irq_mask       = rb532_disable_irq,
 196        .irq_mask_ack   = rb532_mask_and_ack_irq,
 197        .irq_unmask     = rb532_enable_irq,
 198        .irq_set_type   = rb532_set_type,
 199};
 200
 201void __init arch_init_irq(void)
 202{
 203        int i;
 204
 205        pr_info("Initializing IRQ's: %d out of %d\n", RC32434_NR_IRQS, NR_IRQS);
 206
 207        for (i = 0; i < RC32434_NR_IRQS; i++)
 208                irq_set_chip_and_handler(i, &rc32434_irq_type,
 209                                         handle_level_irq);
 210}
 211
 212/* Main Interrupt dispatcher */
 213asmlinkage void plat_irq_dispatch(void)
 214{
 215        unsigned int ip, pend, group;
 216        volatile unsigned int *addr;
 217        unsigned int cp0_cause = read_c0_cause() & read_c0_status();
 218
 219        if (cp0_cause & CAUSEF_IP7) {
 220                do_IRQ(7);
 221        } else {
 222                ip = (cp0_cause & 0x7c00);
 223                if (ip) {
 224                        group = 21 + (fls(ip) - 32);
 225
 226                        addr = intr_group[group].base_addr;
 227
 228                        pend = READ_PEND(addr);
 229                        pend &= ~READ_MASK(addr);       /* only unmasked interrupts */
 230                        pend = 39 + (fls(pend) - 32);
 231                        do_IRQ((group << 5) + pend);
 232                }
 233        }
 234}
 235