1/* 2 * PQ2 ADS-style PCI interrupt controller 3 * 4 * Copyright 2007 Freescale Semiconductor, Inc. 5 * Author: Scott Wood <scottwood@freescale.com> 6 * 7 * Loosely based on mpc82xx ADS support by Vitaly Bordug <vbordug@ru.mvista.com> 8 * Copyright (c) 2006 MontaVista Software, Inc. 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License version 2 as published 12 * by the Free Software Foundation. 13 */ 14 15#include <linux/init.h> 16#include <linux/spinlock.h> 17#include <linux/irq.h> 18#include <linux/types.h> 19#include <linux/bootmem.h> 20#include <linux/slab.h> 21 22#include <asm/io.h> 23#include <asm/prom.h> 24#include <asm/cpm2.h> 25 26#include "pq2.h" 27 28static DEFINE_RAW_SPINLOCK(pci_pic_lock); 29 30struct pq2ads_pci_pic { 31 struct device_node *node; 32 struct irq_host *host; 33 34 struct { 35 u32 stat; 36 u32 mask; 37 } __iomem *regs; 38}; 39 40#define NUM_IRQS 32 41 42static void pq2ads_pci_mask_irq(unsigned int virq) 43{ 44 struct pq2ads_pci_pic *priv = get_irq_chip_data(virq); 45 int irq = NUM_IRQS - virq_to_hw(virq) - 1; 46 47 if (irq != -1) { 48 unsigned long flags; 49 raw_spin_lock_irqsave(&pci_pic_lock, flags); 50 51 setbits32(&priv->regs->mask, 1 << irq); 52 mb(); 53 54 raw_spin_unlock_irqrestore(&pci_pic_lock, flags); 55 } 56} 57 58static void pq2ads_pci_unmask_irq(unsigned int virq) 59{ 60 struct pq2ads_pci_pic *priv = get_irq_chip_data(virq); 61 int irq = NUM_IRQS - virq_to_hw(virq) - 1; 62 63 if (irq != -1) { 64 unsigned long flags; 65 66 raw_spin_lock_irqsave(&pci_pic_lock, flags); 67 clrbits32(&priv->regs->mask, 1 << irq); 68 raw_spin_unlock_irqrestore(&pci_pic_lock, flags); 69 } 70} 71 72static struct irq_chip pq2ads_pci_ic = { 73 .name = "PQ2 ADS PCI", 74 .end = pq2ads_pci_unmask_irq, 75 .mask = pq2ads_pci_mask_irq, 76 .mask_ack = pq2ads_pci_mask_irq, 77 .ack = pq2ads_pci_mask_irq, 78 .unmask = pq2ads_pci_unmask_irq, 79 .enable = pq2ads_pci_unmask_irq, 80 .disable = pq2ads_pci_mask_irq 81}; 82 83static void pq2ads_pci_irq_demux(unsigned int irq, struct irq_desc *desc) 84{ 85 struct pq2ads_pci_pic *priv = desc->handler_data; 86 u32 stat, mask, pend; 87 int bit; 88 89 for (;;) { 90 stat = in_be32(&priv->regs->stat); 91 mask = in_be32(&priv->regs->mask); 92 93 pend = stat & ~mask; 94 95 if (!pend) 96 break; 97 98 for (bit = 0; pend != 0; ++bit, pend <<= 1) { 99 if (pend & 0x80000000) { 100 int virq = irq_linear_revmap(priv->host, bit); 101 generic_handle_irq(virq); 102 } 103 } 104 } 105} 106 107static int pci_pic_host_map(struct irq_host *h, unsigned int virq, 108 irq_hw_number_t hw) 109{ 110 irq_to_desc(virq)->status |= IRQ_LEVEL; 111 set_irq_chip_data(virq, h->host_data); 112 set_irq_chip_and_handler(virq, &pq2ads_pci_ic, handle_level_irq); 113 return 0; 114} 115 116static void pci_host_unmap(struct irq_host *h, unsigned int virq) 117{ 118 /* remove chip and handler */ 119 set_irq_chip_data(virq, NULL); 120 set_irq_chip(virq, NULL); 121} 122 123static struct irq_host_ops pci_pic_host_ops = { 124 .map = pci_pic_host_map, 125 .unmap = pci_host_unmap, 126}; 127 128int __init pq2ads_pci_init_irq(void) 129{ 130 struct pq2ads_pci_pic *priv; 131 struct irq_host *host; 132 struct device_node *np; 133 int ret = -ENODEV; 134 int irq; 135 136 np = of_find_compatible_node(NULL, NULL, "fsl,pq2ads-pci-pic"); 137 if (!np) { 138 printk(KERN_ERR "No pci pic node in device tree.\n"); 139 of_node_put(np); 140 goto out; 141 } 142 143 irq = irq_of_parse_and_map(np, 0); 144 if (irq == NO_IRQ) { 145 printk(KERN_ERR "No interrupt in pci pic node.\n"); 146 of_node_put(np); 147 goto out; 148 } 149 150 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 151 if (!priv) { 152 of_node_put(np); 153 ret = -ENOMEM; 154 goto out_unmap_irq; 155 } 156 157 /* PCI interrupt controller registers: status and mask */ 158 priv->regs = of_iomap(np, 0); 159 if (!priv->regs) { 160 printk(KERN_ERR "Cannot map PCI PIC registers.\n"); 161 goto out_free_bootmem; 162 } 163 164 /* mask all PCI interrupts */ 165 out_be32(&priv->regs->mask, ~0); 166 mb(); 167 168 host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, NUM_IRQS, 169 &pci_pic_host_ops, NUM_IRQS); 170 if (!host) { 171 ret = -ENOMEM; 172 goto out_unmap_regs; 173 } 174 175 host->host_data = priv; 176 177 priv->host = host; 178 host->host_data = priv; 179 set_irq_data(irq, priv); 180 set_irq_chained_handler(irq, pq2ads_pci_irq_demux); 181 182 of_node_put(np); 183 return 0; 184 185out_unmap_regs: 186 iounmap(priv->regs); 187out_free_bootmem: 188 free_bootmem((unsigned long)priv, 189 sizeof(struct pq2ads_pci_pic)); 190 of_node_put(np); 191out_unmap_irq: 192 irq_dispose_mapping(irq); 193out: 194 return ret; 195} 196