arch/mips/rb532/irq.c

   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/module.h>
  33 #include <linux/signal.h>
  34 #include <linux/sched.h>
  35 #include <linux/types.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/ioport.h>
  38 #include <linux/timex.h>
  39 #include <linux/random.h>
  40 #include <linux/delay.h>
  41
  42 #include <asm/bootinfo.h>
  43 #include <asm/time.h>
  44 #include <asm/mipsregs.h>
  45 #include <asm/system.h>
  46
  47 #include <asm/mach-rc32434/irq.h>
  48 #include <asm/mach-rc32434/gpio.h>
  49
  50 struct intr_group {
  51         u32 mask;       /* mask of valid bits in pending/mask registers */
  52         volatile u32 *base_addr;
  53 };
  54
  55 #define RC32434_NR_IRQS  (GROUP4_IRQ_BASE + 32)
  56
  57 #if (NR_IRQS < RC32434_NR_IRQS)
  58 #error Too little irqs defined. Did you override <asm/irq.h> ?
  59 #endif
  60
  61 static const struct intr_group intr_group[NUM_INTR_GROUPS] = {
  62         {
  63                 .mask   = 0x0000efff,
  64                 .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 0 * IC_GROUP_OFFSET)},
  65         {
  66                 .mask   = 0x00001fff,
  67                 .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 1 * IC_GROUP_OFFSET)},
  68         {
  69                 .mask   = 0x00000007,
  70                 .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 2 * IC_GROUP_OFFSET)},
  71         {
  72                 .mask   = 0x0003ffff,
  73                 .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 3 * IC_GROUP_OFFSET)},
  74         {
  75                 .mask   = 0xffffffff,
  76                 .base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 4 * IC_GROUP_OFFSET)}
  77 };
  78
  79 #define READ_PEND(base) (*(base))
  80 #define READ_MASK(base) (*(base + 2))
  81 #define WRITE_MASK(base, val) (*(base + 2) = (val))
  82
  83 static inline int irq_to_group(unsigned int irq_nr)
  84 {
  85         return (irq_nr - GROUP0_IRQ_BASE) >> 5;
  86 }
  87
  88 static inline int group_to_ip(unsigned int group)
  89 {
  90         return group + 2;
  91 }
  92
  93 static inline void enable_local_irq(unsigned int ip)
  94 {
  95         int ipnum = 0x100 << ip;
  96
  97         set_c0_status(ipnum);
  98 }
  99
 100 static inline void disable_local_irq(unsigned int ip)
 101 {
 102         int ipnum = 0x100 << ip;
 103
 104         clear_c0_status(ipnum);
 105 }
 106
 107 static inline void ack_local_irq(unsigned int ip)
 108 {
 109         int ipnum = 0x100 << ip;
 110
 111         clear_c0_cause(ipnum);
 112 }
 113
 114 static void rb532_enable_irq(struct irq_data *d)
 115 {
 116         unsigned int group, intr_bit, irq_nr = d->irq;
 117         int ip = irq_nr - GROUP0_IRQ_BASE;
 118         volatile unsigned int *addr;
 119
 120         if (ip < 0)
 121                 enable_local_irq(irq_nr);
 122         else {
 123                 group = ip >> 5;
 124
 125                 ip &= (1 << 5) - 1;
 126                 intr_bit = 1 << ip;
 127
 128                 enable_local_irq(group_to_ip(group));
 129
 130                 addr = intr_group[group].base_addr;
 131                 WRITE_MASK(addr, READ_MASK(addr) & ~intr_bit);
 132         }
 133 }
 134
 135 static void rb532_disable_irq(struct irq_data *d)
 136 {
 137         unsigned int group, intr_bit, mask, irq_nr = d->irq;
 138         int ip = irq_nr - GROUP0_IRQ_BASE;
 139         volatile unsigned int *addr;
 140
 141         if (ip < 0) {
 142                 disable_local_irq(irq_nr);
 143         } else {
 144                 group = ip >> 5;
 145
 146                 ip &= (1 << 5) - 1;
 147                 intr_bit = 1 << ip;
 148                 addr = intr_group[group].base_addr;
 149                 mask = READ_MASK(addr);
 150                 mask |= intr_bit;
 151                 WRITE_MASK(addr, mask);
 152
 153                 /* There is a maximum of 14 GPIO interrupts */
 154                 if (group == GPIO_MAPPED_IRQ_GROUP && irq_nr <= (GROUP4_IRQ_BASE + 13))
 155                         rb532_gpio_set_istat(0, irq_nr - GPIO_MAPPED_IRQ_BASE);
 156
 157                 /*
 158                  * if there are no more interrupts enabled in this
 159                  * group, disable corresponding IP
 160                  */
 161                 if (mask == intr_group[group].mask)
 162                         disable_local_irq(group_to_ip(group));
 163         }
 164 }
 165
 166 static void rb532_mask_and_ack_irq(struct irq_data *d)
 167 {
 168         rb532_disable_irq(d);
 169         ack_local_irq(group_to_ip(irq_to_group(d->irq)));
 170 }
 171
 172 static int rb532_set_type(struct irq_data *d,  unsigned type)
 173 {
 174         int gpio = d->irq - GPIO_MAPPED_IRQ_BASE;
 175         int group = irq_to_group(d->irq);
 176
 177         if (group != GPIO_MAPPED_IRQ_GROUP || d->irq > (GROUP4_IRQ_BASE + 13))
 178                 return (type == IRQ_TYPE_LEVEL_HIGH) ? 0 : -EINVAL;
 179
 180         switch (type) {
 181         case IRQ_TYPE_LEVEL_HIGH:
 182                 rb532_gpio_set_ilevel(1, gpio);
 183                 break;
 184         case IRQ_TYPE_LEVEL_LOW:
 185                 rb532_gpio_set_ilevel(0, gpio);
 186                 break;
 187         default:
 188                 return -EINVAL;
 189         }
 190
 191         return 0;
 192 }
 193
 194 static struct irq_chip rc32434_irq_type = {
 195         .name           = "RB532",
 196         .irq_ack        = rb532_disable_irq,
 197         .irq_mask       = rb532_disable_irq,
 198         .irq_mask_ack   = rb532_mask_and_ack_irq,
 199         .irq_unmask     = rb532_enable_irq,
 200         .irq_set_type   = rb532_set_type,
 201 };
 202
 203 void __init arch_init_irq(void)
 204 {
 205         int i;
 206
 207         pr_info("Initializing IRQ's: %d out of %d\n", RC32434_NR_IRQS, NR_IRQS);
 208
 209         for (i = 0; i < RC32434_NR_IRQS; i++)
 210                 irq_set_chip_and_handler(i, &rc32434_irq_type,
 211                                          handle_level_irq);
 212 }
 213
 214 /* Main Interrupt dispatcher */
 215 asmlinkage void plat_irq_dispatch(void)
 216 {
 217         unsigned int ip, pend, group;
 218         volatile unsigned int *addr;
 219         unsigned int cp0_cause = read_c0_cause() & read_c0_status();
 220
 221         if (cp0_cause & CAUSEF_IP7) {
 222                 do_IRQ(7);
 223         } else {
 224                 ip = (cp0_cause & 0x7c00);
 225                 if (ip) {
 226                         group = 21 + (fls(ip) - 32);
 227
 228                         addr = intr_group[group].base_addr;
 229
 230                         pend = READ_PEND(addr);
 231                         pend &= ~READ_MASK(addr);       /* only unmasked interrupts */
 232                         pend = 39 + (fls(pend) - 32);
 233                         do_IRQ((group << 5) + pend);
 234                 }
 235         }
 236 }