linux/drivers/parisc/gsc.c
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   1/*
   2 * Interrupt management for most GSC and related devices.
   3 *
   4 * (c) Copyright 1999 Alex deVries for The Puffin Group
   5 * (c) Copyright 1999 Grant Grundler for Hewlett-Packard
   6 * (c) Copyright 1999 Matthew Wilcox
   7 * (c) Copyright 2000 Helge Deller
   8 * (c) Copyright 2001 Matthew Wilcox for Hewlett-Packard
   9 *
  10 *      This program is free software; you can redistribute it and/or modify
  11 *      it under the terms of the GNU General Public License as published by
  12 *      the Free Software Foundation; either version 2 of the License, or
  13 *      (at your option) any later version.
  14 */
  15
  16#include <linux/bitops.h>
  17#include <linux/errno.h>
  18#include <linux/init.h>
  19#include <linux/interrupt.h>
  20#include <linux/ioport.h>
  21#include <linux/module.h>
  22#include <linux/types.h>
  23
  24#include <asm/hardware.h>
  25#include <asm/io.h>
  26
  27#include "gsc.h"
  28
  29#undef DEBUG
  30
  31#ifdef DEBUG
  32#define DEBPRINTK printk
  33#else
  34#define DEBPRINTK(x,...)
  35#endif
  36
  37int gsc_alloc_irq(struct gsc_irq *i)
  38{
  39        int irq = txn_alloc_irq(GSC_EIM_WIDTH);
  40        if (irq < 0) {
  41                printk("cannot get irq\n");
  42                return irq;
  43        }
  44
  45        i->txn_addr = txn_alloc_addr(irq);
  46        i->txn_data = txn_alloc_data(irq);
  47        i->irq = irq;
  48
  49        return irq;
  50}
  51
  52int gsc_claim_irq(struct gsc_irq *i, int irq)
  53{
  54        int c = irq;
  55
  56        irq += CPU_IRQ_BASE; /* virtualize the IRQ first */
  57
  58        irq = txn_claim_irq(irq);
  59        if (irq < 0) {
  60                printk("cannot claim irq %d\n", c);
  61                return irq;
  62        }
  63
  64        i->txn_addr = txn_alloc_addr(irq);
  65        i->txn_data = txn_alloc_data(irq);
  66        i->irq = irq;
  67
  68        return irq;
  69}
  70
  71EXPORT_SYMBOL(gsc_alloc_irq);
  72EXPORT_SYMBOL(gsc_claim_irq);
  73
  74/* Common interrupt demultiplexer used by Asp, Lasi & Wax.  */
  75irqreturn_t gsc_asic_intr(int gsc_asic_irq, void *dev)
  76{
  77        unsigned long irr;
  78        struct gsc_asic *gsc_asic = dev;
  79
  80        irr = gsc_readl(gsc_asic->hpa + OFFSET_IRR);
  81        if (irr == 0)
  82                return IRQ_NONE;
  83
  84        DEBPRINTK("%s intr, mask=0x%x\n", gsc_asic->name, irr);
  85
  86        do {
  87                int local_irq = __ffs(irr);
  88                unsigned int irq = gsc_asic->global_irq[local_irq];
  89                __do_IRQ(irq);
  90                irr &= ~(1 << local_irq);
  91        } while (irr);
  92
  93        return IRQ_HANDLED;
  94}
  95
  96int gsc_find_local_irq(unsigned int irq, int *global_irqs, int limit)
  97{
  98        int local_irq;
  99
 100        for (local_irq = 0; local_irq < limit; local_irq++) {
 101                if (global_irqs[local_irq] == irq)
 102                        return local_irq;
 103        }
 104
 105        return NO_IRQ;
 106}
 107
 108static void gsc_asic_disable_irq(unsigned int irq)
 109{
 110        struct irq_desc *desc = irq_to_desc(irq);
 111        struct gsc_asic *irq_dev = desc->chip_data;
 112        int local_irq = gsc_find_local_irq(irq, irq_dev->global_irq, 32);
 113        u32 imr;
 114
 115        DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, irq,
 116                        irq_dev->name, imr);
 117
 118        /* Disable the IRQ line by clearing the bit in the IMR */
 119        imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
 120        imr &= ~(1 << local_irq);
 121        gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
 122}
 123
 124static void gsc_asic_enable_irq(unsigned int irq)
 125{
 126        struct irq_desc *desc = irq_to_desc(irq);
 127        struct gsc_asic *irq_dev = desc->chip_data;
 128        int local_irq = gsc_find_local_irq(irq, irq_dev->global_irq, 32);
 129        u32 imr;
 130
 131        DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, irq,
 132                        irq_dev->name, imr);
 133
 134        /* Enable the IRQ line by setting the bit in the IMR */
 135        imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
 136        imr |= 1 << local_irq;
 137        gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
 138        /*
 139         * FIXME: read IPR to make sure the IRQ isn't already pending.
 140         *   If so, we need to read IRR and manually call do_irq().
 141         */
 142}
 143
 144static unsigned int gsc_asic_startup_irq(unsigned int irq)
 145{
 146        gsc_asic_enable_irq(irq);
 147        return 0;
 148}
 149
 150static struct irq_chip gsc_asic_interrupt_type = {
 151        .name    =      "GSC-ASIC",
 152        .startup =      gsc_asic_startup_irq,
 153        .shutdown =     gsc_asic_disable_irq,
 154        .enable =       gsc_asic_enable_irq,
 155        .disable =      gsc_asic_disable_irq,
 156        .ack =          no_ack_irq,
 157        .end =          no_end_irq,
 158};
 159
 160int gsc_assign_irq(struct irq_chip *type, void *data)
 161{
 162        static int irq = GSC_IRQ_BASE;
 163        struct irq_desc *desc;
 164
 165        if (irq > GSC_IRQ_MAX)
 166                return NO_IRQ;
 167
 168        desc = irq_to_desc(irq);
 169        desc->chip = type;
 170        desc->chip_data = data;
 171        return irq++;
 172}
 173
 174void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp)
 175{
 176        int irq = asic->global_irq[local_irq];
 177        
 178        if (irq <= 0) {
 179                irq = gsc_assign_irq(&gsc_asic_interrupt_type, asic);
 180                if (irq == NO_IRQ)
 181                        return;
 182
 183                asic->global_irq[local_irq] = irq;
 184        }
 185        *irqp = irq;
 186}
 187
 188struct gsc_fixup_struct {
 189        void (*choose_irq)(struct parisc_device *, void *);
 190        void *ctrl;
 191};
 192
 193static int gsc_fixup_irqs_callback(struct device *dev, void *data)
 194{
 195        struct parisc_device *padev = to_parisc_device(dev);
 196        struct gsc_fixup_struct *gf = data;
 197
 198        /* work-around for 715/64 and others which have parent
 199           at path [5] and children at path [5/0/x] */
 200        if (padev->id.hw_type == HPHW_FAULTY)
 201                gsc_fixup_irqs(padev, gf->ctrl, gf->choose_irq);
 202        gf->choose_irq(padev, gf->ctrl);
 203
 204        return 0;
 205}
 206
 207void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl,
 208                        void (*choose_irq)(struct parisc_device *, void *))
 209{
 210        struct gsc_fixup_struct data = {
 211                .choose_irq     = choose_irq,
 212                .ctrl           = ctrl,
 213        };
 214
 215        device_for_each_child(&parent->dev, &data, gsc_fixup_irqs_callback);
 216}
 217
 218int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic)
 219{
 220        struct resource *res;
 221        int i;
 222
 223        gsc_asic->gsc = parent;
 224
 225        /* Initialise local irq -> global irq mapping */
 226        for (i = 0; i < 32; i++) {
 227                gsc_asic->global_irq[i] = NO_IRQ;
 228        }
 229
 230        /* allocate resource region */
 231        res = request_mem_region(gsc_asic->hpa, 0x100000, gsc_asic->name);
 232        if (res) {
 233                res->flags = IORESOURCE_MEM;    /* do not mark it busy ! */
 234        }
 235
 236#if 0
 237        printk(KERN_WARNING "%s IRQ %d EIM 0x%x", gsc_asic->name,
 238                        parent->irq, gsc_asic->eim);
 239        if (gsc_readl(gsc_asic->hpa + OFFSET_IMR))
 240                printk("  IMR is non-zero! (0x%x)",
 241                                gsc_readl(gsc_asic->hpa + OFFSET_IMR));
 242        printk("\n");
 243#endif
 244
 245        return 0;
 246}
 247
 248extern struct parisc_driver lasi_driver;
 249extern struct parisc_driver asp_driver;
 250extern struct parisc_driver wax_driver;
 251
 252void __init gsc_init(void)
 253{
 254#ifdef CONFIG_GSC_LASI
 255        register_parisc_driver(&lasi_driver);
 256        register_parisc_driver(&asp_driver);
 257#endif
 258#ifdef CONFIG_GSC_WAX
 259        register_parisc_driver(&wax_driver);
 260#endif
 261}
 262