arch/mips/pnx8550/common/int.c

   1 /*
   2  *
   3  * Copyright (C) 2005 Embedded Alley Solutions, Inc
   4  * Ported to 2.6.
   5  *
   6  * Per Hallsmark, per.hallsmark@mvista.com
   7  * Copyright (C) 2000, 2001 MIPS Technologies, Inc.
   8  * Copyright (C) 2001 Ralf Baechle
   9  *
  10  * Cleaned up and bug fixing: Pete Popov, ppopov@embeddedalley.com
  11  *
  12  *  This program is free software; you can distribute it and/or modify it
  13  *  under the terms of the GNU General Public License (Version 2) as
  14  *  published by the Free Software Foundation.
  15  *
  16  *  This program is distributed in the hope it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with this program; if not, write to the Free Software Foundation, Inc.,
  23  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  24  *
  25  */
  26 #include <linux/compiler.h>
  27 #include <linux/init.h>
  28 #include <linux/irq.h>
  29 #include <linux/sched.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/kernel_stat.h>
  32 #include <linux/random.h>
  33 #include <linux/module.h>
  34
  35 #include <asm/io.h>
  36 #include <int.h>
  37 #include <uart.h>
  38
  39 /* default prio for interrupts */
  40 /* first one is a no-no so therefore always prio 0 (disabled) */
  41 static char gic_prio[PNX8550_INT_GIC_TOTINT] = {
  42         0, 1, 1, 1, 1, 15, 1, 1, 1, 1,  //   0 -  9
  43         1, 1, 1, 1, 1, 1, 1, 1, 1, 1,   //  10 - 19
  44         1, 1, 1, 1, 1, 1, 1, 1, 1, 1,   //  20 - 29
  45         1, 1, 1, 1, 1, 1, 1, 1, 1, 1,   //  30 - 39
  46         1, 1, 1, 1, 1, 1, 1, 1, 1, 1,   //  40 - 49
  47         1, 1, 1, 1, 1, 1, 1, 1, 2, 1,   //  50 - 59
  48         1, 1, 1, 1, 1, 1, 1, 1, 1, 1,   //  60 - 69
  49         1                       //  70
  50 };
  51
  52 static void hw0_irqdispatch(int irq)
  53 {
  54         /* find out which interrupt */
  55         irq = PNX8550_GIC_VECTOR_0 >> 3;
  56
  57         if (irq == 0) {
  58                 printk("hw0_irqdispatch: irq 0, spurious interrupt?\n");
  59                 return;
  60         }
  61         do_IRQ(PNX8550_INT_GIC_MIN + irq);
  62 }
  63
  64
  65 static void timer_irqdispatch(int irq)
  66 {
  67         irq = (0x01c0 & read_c0_config7()) >> 6;
  68
  69         if (unlikely(irq == 0)) {
  70                 printk("timer_irqdispatch: irq 0, spurious interrupt?\n");
  71                 return;
  72         }
  73
  74         if (irq & 0x1)
  75                 do_IRQ(PNX8550_INT_TIMER1);
  76         if (irq & 0x2)
  77                 do_IRQ(PNX8550_INT_TIMER2);
  78         if (irq & 0x4)
  79                 do_IRQ(PNX8550_INT_TIMER3);
  80 }
  81
  82 asmlinkage void plat_irq_dispatch(void)
  83 {
  84         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
  85
  86         if (pending & STATUSF_IP2)
  87                 hw0_irqdispatch(2);
  88         else if (pending & STATUSF_IP7) {
  89                 if (read_c0_config7() & 0x01c0)
  90                         timer_irqdispatch(7);
  91         } else
  92                 spurious_interrupt();
  93 }
  94
  95 static inline void modify_cp0_intmask(unsigned clr_mask, unsigned set_mask)
  96 {
  97         unsigned long status = read_c0_status();
  98
  99         status &= ~((clr_mask & 0xFF) << 8);
 100         status |= (set_mask & 0xFF) << 8;
 101
 102         write_c0_status(status);
 103 }
 104
 105 static inline void mask_gic_int(unsigned int irq_nr)
 106 {
 107         /* interrupt disabled, bit 26(WE_ENABLE)=1 and bit 16(enable)=0 */
 108         PNX8550_GIC_REQ(irq_nr) = 1<<28; /* set priority to 0 */
 109 }
 110
 111 static inline void unmask_gic_int(unsigned int irq_nr)
 112 {
 113         /* set prio mask to lower four bits and enable interrupt */
 114         PNX8550_GIC_REQ(irq_nr) = (1<<26 | 1<<16) | (1<<28) | gic_prio[irq_nr];
 115 }
 116
 117 static inline void mask_irq(struct irq_data *d)
 118 {
 119         unsigned int irq_nr = d->irq;
 120
 121         if ((PNX8550_INT_CP0_MIN <= irq_nr) && (irq_nr <= PNX8550_INT_CP0_MAX)) {
 122                 modify_cp0_intmask(1 << irq_nr, 0);
 123         } else if ((PNX8550_INT_GIC_MIN <= irq_nr) &&
 124                 (irq_nr <= PNX8550_INT_GIC_MAX)) {
 125                 mask_gic_int(irq_nr - PNX8550_INT_GIC_MIN);
 126         } else if ((PNX8550_INT_TIMER_MIN <= irq_nr) &&
 127                 (irq_nr <= PNX8550_INT_TIMER_MAX)) {
 128                 modify_cp0_intmask(1 << 7, 0);
 129         } else {
 130                 printk("mask_irq: irq %d doesn't exist!\n", irq_nr);
 131         }
 132 }
 133
 134 static inline void unmask_irq(struct irq_data *d)
 135 {
 136         unsigned int irq_nr = d->irq;
 137
 138         if ((PNX8550_INT_CP0_MIN <= irq_nr) && (irq_nr <= PNX8550_INT_CP0_MAX)) {
 139                 modify_cp0_intmask(0, 1 << irq_nr);
 140         } else if ((PNX8550_INT_GIC_MIN <= irq_nr) &&
 141                 (irq_nr <= PNX8550_INT_GIC_MAX)) {
 142                 unmask_gic_int(irq_nr - PNX8550_INT_GIC_MIN);
 143         } else if ((PNX8550_INT_TIMER_MIN <= irq_nr) &&
 144                 (irq_nr <= PNX8550_INT_TIMER_MAX)) {
 145                 modify_cp0_intmask(0, 1 << 7);
 146         } else {
 147                 printk("mask_irq: irq %d doesn't exist!\n", irq_nr);
 148         }
 149 }
 150
 151 int pnx8550_set_gic_priority(int irq, int priority)
 152 {
 153         int gic_irq = irq-PNX8550_INT_GIC_MIN;
 154         int prev_priority = PNX8550_GIC_REQ(gic_irq) & 0xf;
 155
 156         gic_prio[gic_irq] = priority;
 157         PNX8550_GIC_REQ(gic_irq) |= (0x10000000 | gic_prio[gic_irq]);
 158
 159         return prev_priority;
 160 }
 161
 162 static struct irq_chip level_irq_type = {
 163         .name =         "PNX Level IRQ",
 164         .irq_mask =     mask_irq,
 165         .irq_unmask =   unmask_irq,
 166 };
 167
 168 static struct irqaction gic_action = {
 169         .handler =      no_action,
 170         .flags =        IRQF_NO_THREAD,
 171         .name =         "GIC",
 172 };
 173
 174 static struct irqaction timer_action = {
 175         .handler =      no_action,
 176         .flags =        IRQF_TIMER,
 177         .name =         "Timer",
 178 };
 179
 180 void __init arch_init_irq(void)
 181 {
 182         int i;
 183         int configPR;
 184
 185         for (i = 0; i < PNX8550_INT_CP0_TOTINT; i++)
 186                 irq_set_chip_and_handler(i, &level_irq_type, handle_level_irq);
 187
 188         /* init of GIC/IPC interrupts */
 189         /* should be done before cp0 since cp0 init enables the GIC int */
 190         for (i = PNX8550_INT_GIC_MIN; i <= PNX8550_INT_GIC_MAX; i++) {
 191                 int gic_int_line = i - PNX8550_INT_GIC_MIN;
 192                 if (gic_int_line == 0 )
 193                         continue;       // don't fiddle with int 0
 194                 /*
 195                  * enable change of TARGET, ENABLE and ACTIVE_LOW bits
 196                  * set TARGET        0 to route through hw0 interrupt
 197                  * set ACTIVE_LOW    0 active high  (correct?)
 198                  *
 199                  * We really should setup an interrupt description table
 200                  * to do this nicely.
 201                  * Note, PCI INTA is active low on the bus, but inverted
 202                  * in the GIC, so to us it's active high.
 203                  */
 204                 PNX8550_GIC_REQ(i - PNX8550_INT_GIC_MIN) = 0x1E000000;
 205
 206                 /* mask/priority is still 0 so we will not get any
 207                  * interrupts until it is unmasked */
 208
 209                 irq_set_chip_and_handler(i, &level_irq_type, handle_level_irq);
 210         }
 211
 212         /* Priority level 0 */
 213         PNX8550_GIC_PRIMASK_0 = PNX8550_GIC_PRIMASK_1 = 0;
 214
 215         /* Set int vector table address */
 216         PNX8550_GIC_VECTOR_0 = PNX8550_GIC_VECTOR_1 = 0;
 217
 218         irq_set_chip_and_handler(MIPS_CPU_GIC_IRQ, &level_irq_type,
 219                                  handle_level_irq);
 220         setup_irq(MIPS_CPU_GIC_IRQ, &gic_action);
 221
 222         /* init of Timer interrupts */
 223         for (i = PNX8550_INT_TIMER_MIN; i <= PNX8550_INT_TIMER_MAX; i++)
 224                 irq_set_chip_and_handler(i, &level_irq_type, handle_level_irq);
 225
 226         /* Stop Timer 1-3 */
 227         configPR = read_c0_config7();
 228         configPR |= 0x00000038;
 229         write_c0_config7(configPR);
 230
 231         irq_set_chip_and_handler(MIPS_CPU_TIMER_IRQ, &level_irq_type,
 232                                  handle_level_irq);
 233         setup_irq(MIPS_CPU_TIMER_IRQ, &timer_action);
 234 }
 235
 236 EXPORT_SYMBOL(pnx8550_set_gic_priority);