linux/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * PQ2 ADS-style PCI interrupt controller
   4 *
   5 * Copyright 2007 Freescale Semiconductor, Inc.
   6 * Author: Scott Wood <scottwood@freescale.com>
   7 *
   8 * Loosely based on mpc82xx ADS support by Vitaly Bordug <vbordug@ru.mvista.com>
   9 * Copyright (c) 2006 MontaVista Software, Inc.
  10 */
  11
  12#include <linux/init.h>
  13#include <linux/spinlock.h>
  14#include <linux/irq.h>
  15#include <linux/types.h>
  16#include <linux/slab.h>
  17
  18#include <asm/io.h>
  19#include <asm/prom.h>
  20#include <asm/cpm2.h>
  21
  22#include "pq2.h"
  23
  24static DEFINE_RAW_SPINLOCK(pci_pic_lock);
  25
  26struct pq2ads_pci_pic {
  27        struct device_node *node;
  28        struct irq_domain *host;
  29
  30        struct {
  31                u32 stat;
  32                u32 mask;
  33        } __iomem *regs;
  34};
  35
  36#define NUM_IRQS 32
  37
  38static void pq2ads_pci_mask_irq(struct irq_data *d)
  39{
  40        struct pq2ads_pci_pic *priv = irq_data_get_irq_chip_data(d);
  41        int irq = NUM_IRQS - irqd_to_hwirq(d) - 1;
  42
  43        if (irq != -1) {
  44                unsigned long flags;
  45                raw_spin_lock_irqsave(&pci_pic_lock, flags);
  46
  47                setbits32(&priv->regs->mask, 1 << irq);
  48                mb();
  49
  50                raw_spin_unlock_irqrestore(&pci_pic_lock, flags);
  51        }
  52}
  53
  54static void pq2ads_pci_unmask_irq(struct irq_data *d)
  55{
  56        struct pq2ads_pci_pic *priv = irq_data_get_irq_chip_data(d);
  57        int irq = NUM_IRQS - irqd_to_hwirq(d) - 1;
  58
  59        if (irq != -1) {
  60                unsigned long flags;
  61
  62                raw_spin_lock_irqsave(&pci_pic_lock, flags);
  63                clrbits32(&priv->regs->mask, 1 << irq);
  64                raw_spin_unlock_irqrestore(&pci_pic_lock, flags);
  65        }
  66}
  67
  68static struct irq_chip pq2ads_pci_ic = {
  69        .name = "PQ2 ADS PCI",
  70        .irq_mask = pq2ads_pci_mask_irq,
  71        .irq_mask_ack = pq2ads_pci_mask_irq,
  72        .irq_ack = pq2ads_pci_mask_irq,
  73        .irq_unmask = pq2ads_pci_unmask_irq,
  74        .irq_enable = pq2ads_pci_unmask_irq,
  75        .irq_disable = pq2ads_pci_mask_irq
  76};
  77
  78static void pq2ads_pci_irq_demux(struct irq_desc *desc)
  79{
  80        struct pq2ads_pci_pic *priv = irq_desc_get_handler_data(desc);
  81        u32 stat, mask, pend;
  82        int bit;
  83
  84        for (;;) {
  85                stat = in_be32(&priv->regs->stat);
  86                mask = in_be32(&priv->regs->mask);
  87
  88                pend = stat & ~mask;
  89
  90                if (!pend)
  91                        break;
  92
  93                for (bit = 0; pend != 0; ++bit, pend <<= 1) {
  94                        if (pend & 0x80000000) {
  95                                int virq = irq_linear_revmap(priv->host, bit);
  96                                generic_handle_irq(virq);
  97                        }
  98                }
  99        }
 100}
 101
 102static int pci_pic_host_map(struct irq_domain *h, unsigned int virq,
 103                            irq_hw_number_t hw)
 104{
 105        irq_set_status_flags(virq, IRQ_LEVEL);
 106        irq_set_chip_data(virq, h->host_data);
 107        irq_set_chip_and_handler(virq, &pq2ads_pci_ic, handle_level_irq);
 108        return 0;
 109}
 110
 111static const struct irq_domain_ops pci_pic_host_ops = {
 112        .map = pci_pic_host_map,
 113};
 114
 115int __init pq2ads_pci_init_irq(void)
 116{
 117        struct pq2ads_pci_pic *priv;
 118        struct irq_domain *host;
 119        struct device_node *np;
 120        int ret = -ENODEV;
 121        int irq;
 122
 123        np = of_find_compatible_node(NULL, NULL, "fsl,pq2ads-pci-pic");
 124        if (!np) {
 125                printk(KERN_ERR "No pci pic node in device tree.\n");
 126                goto out;
 127        }
 128
 129        irq = irq_of_parse_and_map(np, 0);
 130        if (!irq) {
 131                printk(KERN_ERR "No interrupt in pci pic node.\n");
 132                goto out_put_node;
 133        }
 134
 135        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 136        if (!priv) {
 137                ret = -ENOMEM;
 138                goto out_unmap_irq;
 139        }
 140
 141        /* PCI interrupt controller registers: status and mask */
 142        priv->regs = of_iomap(np, 0);
 143        if (!priv->regs) {
 144                printk(KERN_ERR "Cannot map PCI PIC registers.\n");
 145                goto out_free_kmalloc;
 146        }
 147
 148        /* mask all PCI interrupts */
 149        out_be32(&priv->regs->mask, ~0);
 150        mb();
 151
 152        host = irq_domain_add_linear(np, NUM_IRQS, &pci_pic_host_ops, priv);
 153        if (!host) {
 154                ret = -ENOMEM;
 155                goto out_unmap_regs;
 156        }
 157
 158        priv->host = host;
 159        irq_set_handler_data(irq, priv);
 160        irq_set_chained_handler(irq, pq2ads_pci_irq_demux);
 161        ret = 0;
 162        goto out_put_node;
 163
 164out_unmap_regs:
 165        iounmap(priv->regs);
 166out_free_kmalloc:
 167        kfree(priv);
 168out_unmap_irq:
 169        irq_dispose_mapping(irq);
 170out_put_node:
 171        of_node_put(np);
 172out:
 173        return ret;
 174}
 175
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.