drivers/irqchip/irq-orion.c

   1 /*
   2  * Marvell Orion SoCs IRQ chip driver.
   3  *
   4  * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
   5  *
   6  * This file is licensed under the terms of the GNU General Public
   7  * License version 2.  This program is licensed "as is" without any
   8  * warranty of any kind, whether express or implied.
   9  */
  10
  11 #include <linux/io.h>
  12 #include <linux/irq.h>
  13 #include <linux/of.h>
  14 #include <linux/of_address.h>
  15 #include <linux/of_irq.h>
  16 #include <asm/exception.h>
  17 #include <asm/mach/irq.h>
  18
  19 #include "irqchip.h"
  20
  21 /*
  22  * Orion SoC main interrupt controller
  23  */
  24 #define ORION_IRQS_PER_CHIP             32
  25
  26 #define ORION_IRQ_CAUSE                 0x00
  27 #define ORION_IRQ_MASK                  0x04
  28 #define ORION_IRQ_FIQ_MASK              0x08
  29 #define ORION_IRQ_ENDP_MASK             0x0c
  30
  31 static struct irq_domain *orion_irq_domain;
  32
  33 static asmlinkage void
  34 __exception_irq_entry orion_handle_irq(struct pt_regs *regs)
  35 {
  36         struct irq_domain_chip_generic *dgc = orion_irq_domain->gc;
  37         int n, base = 0;
  38
  39         for (n = 0; n < dgc->num_chips; n++, base += ORION_IRQS_PER_CHIP) {
  40                 struct irq_chip_generic *gc =
  41                         irq_get_domain_generic_chip(orion_irq_domain, base);
  42                 u32 stat = readl_relaxed(gc->reg_base + ORION_IRQ_CAUSE) &
  43                         gc->mask_cache;
  44                 while (stat) {
  45                         u32 hwirq = ffs(stat) - 1;
  46                         u32 irq = irq_find_mapping(orion_irq_domain,
  47                                                    gc->irq_base + hwirq);
  48                         handle_IRQ(irq, regs);
  49                         stat &= ~(1 << hwirq);
  50                 }
  51         }
  52 }
  53
  54 static int __init orion_irq_init(struct device_node *np,
  55                                  struct device_node *parent)
  56 {
  57         unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
  58         int n, ret, base, num_chips = 0;
  59         struct resource r;
  60
  61         /* count number of irq chips by valid reg addresses */
  62         while (of_address_to_resource(np, num_chips, &r) == 0)
  63                 num_chips++;
  64
  65         orion_irq_domain = irq_domain_add_linear(np,
  66                                 num_chips * ORION_IRQS_PER_CHIP,
  67                                 &irq_generic_chip_ops, NULL);
  68         if (!orion_irq_domain)
  69                 panic("%s: unable to add irq domain\n", np->name);
  70
  71         ret = irq_alloc_domain_generic_chips(orion_irq_domain,
  72                                 ORION_IRQS_PER_CHIP, 1, np->name,
  73                                 handle_level_irq, clr, 0,
  74                                 IRQ_GC_INIT_MASK_CACHE);
  75         if (ret)
  76                 panic("%s: unable to alloc irq domain gc\n", np->name);
  77
  78         for (n = 0, base = 0; n < num_chips; n++, base += ORION_IRQS_PER_CHIP) {
  79                 struct irq_chip_generic *gc =
  80                         irq_get_domain_generic_chip(orion_irq_domain, base);
  81
  82                 of_address_to_resource(np, n, &r);
  83
  84                 if (!request_mem_region(r.start, resource_size(&r), np->name))
  85                         panic("%s: unable to request mem region %d",
  86                               np->name, n);
  87
  88                 gc->reg_base = ioremap(r.start, resource_size(&r));
  89                 if (!gc->reg_base)
  90                         panic("%s: unable to map resource %d", np->name, n);
  91
  92                 gc->chip_types[0].regs.mask = ORION_IRQ_MASK;
  93                 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
  94                 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
  95
  96                 /* mask all interrupts */
  97                 writel(0, gc->reg_base + ORION_IRQ_MASK);
  98         }
  99
 100         set_handle_irq(orion_handle_irq);
 101         return 0;
 102 }
 103 IRQCHIP_DECLARE(orion_intc, "marvell,orion-intc", orion_irq_init);
 104
 105 /*
 106  * Orion SoC bridge interrupt controller
 107  */
 108 #define ORION_BRIDGE_IRQ_CAUSE  0x00
 109 #define ORION_BRIDGE_IRQ_MASK   0x04
 110
 111 static void orion_bridge_irq_handler(unsigned int irq, struct irq_desc *desc)
 112 {
 113         struct irq_domain *d = irq_get_handler_data(irq);
 114
 115         struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, 0);
 116         u32 stat = readl_relaxed(gc->reg_base + ORION_BRIDGE_IRQ_CAUSE) &
 117                    gc->mask_cache;
 118
 119         while (stat) {
 120                 u32 hwirq = ffs(stat) - 1;
 121
 122                 generic_handle_irq(irq_find_mapping(d, gc->irq_base + hwirq));
 123                 stat &= ~(1 << hwirq);
 124         }
 125 }
 126
 127 /*
 128  * Bridge IRQ_CAUSE is asserted regardless of IRQ_MASK register.
 129  * To avoid interrupt events on stale irqs, we clear them before unmask.
 130  */
 131 static unsigned int orion_bridge_irq_startup(struct irq_data *d)
 132 {
 133         struct irq_chip_type *ct = irq_data_get_chip_type(d);
 134
 135         ct->chip.irq_ack(d);
 136         ct->chip.irq_unmask(d);
 137         return 0;
 138 }
 139
 140 static int __init orion_bridge_irq_init(struct device_node *np,
 141                                         struct device_node *parent)
 142 {
 143         unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 144         struct resource r;
 145         struct irq_domain *domain;
 146         struct irq_chip_generic *gc;
 147         int ret, irq, nrirqs = 32;
 148
 149         /* get optional number of interrupts provided */
 150         of_property_read_u32(np, "marvell,#interrupts", &nrirqs);
 151
 152         domain = irq_domain_add_linear(np, nrirqs,
 153                                        &irq_generic_chip_ops, NULL);
 154         if (!domain) {
 155                 pr_err("%s: unable to add irq domain\n", np->name);
 156                 return -ENOMEM;
 157         }
 158
 159         ret = irq_alloc_domain_generic_chips(domain, nrirqs, 1, np->name,
 160                              handle_edge_irq, clr, 0, IRQ_GC_INIT_MASK_CACHE);
 161         if (ret) {
 162                 pr_err("%s: unable to alloc irq domain gc\n", np->name);
 163                 return ret;
 164         }
 165
 166         ret = of_address_to_resource(np, 0, &r);
 167         if (ret) {
 168                 pr_err("%s: unable to get resource\n", np->name);
 169                 return ret;
 170         }
 171
 172         if (!request_mem_region(r.start, resource_size(&r), np->name)) {
 173                 pr_err("%s: unable to request mem region\n", np->name);
 174                 return -ENOMEM;
 175         }
 176
 177         /* Map the parent interrupt for the chained handler */
 178         irq = irq_of_parse_and_map(np, 0);
 179         if (irq <= 0) {
 180                 pr_err("%s: unable to parse irq\n", np->name);
 181                 return -EINVAL;
 182         }
 183
 184         gc = irq_get_domain_generic_chip(domain, 0);
 185         gc->reg_base = ioremap(r.start, resource_size(&r));
 186         if (!gc->reg_base) {
 187                 pr_err("%s: unable to map resource\n", np->name);
 188                 return -ENOMEM;
 189         }
 190
 191         gc->chip_types[0].regs.ack = ORION_BRIDGE_IRQ_CAUSE;
 192         gc->chip_types[0].regs.mask = ORION_BRIDGE_IRQ_MASK;
 193         gc->chip_types[0].chip.irq_startup = orion_bridge_irq_startup;
 194         gc->chip_types[0].chip.irq_ack = irq_gc_ack_clr_bit;
 195         gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
 196         gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
 197
 198         /* mask and clear all interrupts */
 199         writel(0, gc->reg_base + ORION_BRIDGE_IRQ_MASK);
 200         writel(0, gc->reg_base + ORION_BRIDGE_IRQ_CAUSE);
 201
 202         irq_set_handler_data(irq, domain);
 203         irq_set_chained_handler(irq, orion_bridge_irq_handler);
 204
 205         return 0;
 206 }
 207 IRQCHIP_DECLARE(orion_bridge_intc,
 208                 "marvell,orion-bridge-intc", orion_bridge_irq_init);