linux/drivers/irqchip/irq-xtensa-mx.c
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   1/*
   2 * Xtensa MX interrupt distributor
   3 *
   4 * Copyright (C) 2002 - 2013 Tensilica, Inc.
   5 *
   6 * This file is subject to the terms and conditions of the GNU General Public
   7 * License.  See the file "COPYING" in the main directory of this archive
   8 * for more details.
   9 */
  10
  11#include <linux/interrupt.h>
  12#include <linux/irqdomain.h>
  13#include <linux/irq.h>
  14#include <linux/irqchip.h>
  15#include <linux/of.h>
  16
  17#include <asm/mxregs.h>
  18
  19#define HW_IRQ_IPI_COUNT 2
  20#define HW_IRQ_MX_BASE 2
  21#define HW_IRQ_EXTERN_BASE 3
  22
  23static DEFINE_PER_CPU(unsigned int, cached_irq_mask);
  24
  25static int xtensa_mx_irq_map(struct irq_domain *d, unsigned int irq,
  26                irq_hw_number_t hw)
  27{
  28        if (hw < HW_IRQ_IPI_COUNT) {
  29                struct irq_chip *irq_chip = d->host_data;
  30                irq_set_chip_and_handler_name(irq, irq_chip,
  31                                handle_percpu_irq, "ipi");
  32                irq_set_status_flags(irq, IRQ_LEVEL);
  33                return 0;
  34        }
  35        irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq)));
  36        return xtensa_irq_map(d, irq, hw);
  37}
  38
  39/*
  40 * Device Tree IRQ specifier translation function which works with one or
  41 * two cell bindings. First cell value maps directly to the hwirq number.
  42 * Second cell if present specifies whether hwirq number is external (1) or
  43 * internal (0).
  44 */
  45static int xtensa_mx_irq_domain_xlate(struct irq_domain *d,
  46                struct device_node *ctrlr,
  47                const u32 *intspec, unsigned int intsize,
  48                unsigned long *out_hwirq, unsigned int *out_type)
  49{
  50        return xtensa_irq_domain_xlate(intspec, intsize,
  51                        intspec[0], intspec[0] + HW_IRQ_EXTERN_BASE,
  52                        out_hwirq, out_type);
  53}
  54
  55static const struct irq_domain_ops xtensa_mx_irq_domain_ops = {
  56        .xlate = xtensa_mx_irq_domain_xlate,
  57        .map = xtensa_mx_irq_map,
  58};
  59
  60void secondary_init_irq(void)
  61{
  62        __this_cpu_write(cached_irq_mask,
  63                        XCHAL_INTTYPE_MASK_EXTERN_EDGE |
  64                        XCHAL_INTTYPE_MASK_EXTERN_LEVEL);
  65        xtensa_set_sr(XCHAL_INTTYPE_MASK_EXTERN_EDGE |
  66                        XCHAL_INTTYPE_MASK_EXTERN_LEVEL, intenable);
  67}
  68
  69static void xtensa_mx_irq_mask(struct irq_data *d)
  70{
  71        unsigned int mask = 1u << d->hwirq;
  72
  73        if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
  74                    XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
  75                unsigned int ext_irq = xtensa_get_ext_irq_no(d->hwirq);
  76
  77                if (ext_irq >= HW_IRQ_MX_BASE) {
  78                        set_er(1u << (ext_irq - HW_IRQ_MX_BASE), MIENG);
  79                        return;
  80                }
  81        }
  82        mask = __this_cpu_read(cached_irq_mask) & ~mask;
  83        __this_cpu_write(cached_irq_mask, mask);
  84        xtensa_set_sr(mask, intenable);
  85}
  86
  87static void xtensa_mx_irq_unmask(struct irq_data *d)
  88{
  89        unsigned int mask = 1u << d->hwirq;
  90
  91        if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
  92                    XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
  93                unsigned int ext_irq = xtensa_get_ext_irq_no(d->hwirq);
  94
  95                if (ext_irq >= HW_IRQ_MX_BASE) {
  96                        set_er(1u << (ext_irq - HW_IRQ_MX_BASE), MIENGSET);
  97                        return;
  98                }
  99        }
 100        mask |= __this_cpu_read(cached_irq_mask);
 101        __this_cpu_write(cached_irq_mask, mask);
 102        xtensa_set_sr(mask, intenable);
 103}
 104
 105static void xtensa_mx_irq_enable(struct irq_data *d)
 106{
 107        xtensa_mx_irq_unmask(d);
 108}
 109
 110static void xtensa_mx_irq_disable(struct irq_data *d)
 111{
 112        xtensa_mx_irq_mask(d);
 113}
 114
 115static void xtensa_mx_irq_ack(struct irq_data *d)
 116{
 117        xtensa_set_sr(1 << d->hwirq, intclear);
 118}
 119
 120static int xtensa_mx_irq_retrigger(struct irq_data *d)
 121{
 122        unsigned int mask = 1u << d->hwirq;
 123
 124        if (WARN_ON(mask & ~XCHAL_INTTYPE_MASK_SOFTWARE))
 125                return 0;
 126        xtensa_set_sr(mask, intset);
 127        return 1;
 128}
 129
 130static int xtensa_mx_irq_set_affinity(struct irq_data *d,
 131                const struct cpumask *dest, bool force)
 132{
 133        int cpu = cpumask_any_and(dest, cpu_online_mask);
 134        unsigned mask = 1u << cpu;
 135
 136        set_er(mask, MIROUT(d->hwirq - HW_IRQ_MX_BASE));
 137        irq_data_update_effective_affinity(d, cpumask_of(cpu));
 138
 139        return 0;
 140
 141}
 142
 143static struct irq_chip xtensa_mx_irq_chip = {
 144        .name           = "xtensa-mx",
 145        .irq_enable     = xtensa_mx_irq_enable,
 146        .irq_disable    = xtensa_mx_irq_disable,
 147        .irq_mask       = xtensa_mx_irq_mask,
 148        .irq_unmask     = xtensa_mx_irq_unmask,
 149        .irq_ack        = xtensa_mx_irq_ack,
 150        .irq_retrigger  = xtensa_mx_irq_retrigger,
 151        .irq_set_affinity = xtensa_mx_irq_set_affinity,
 152};
 153
 154int __init xtensa_mx_init_legacy(struct device_node *interrupt_parent)
 155{
 156        struct irq_domain *root_domain =
 157                irq_domain_add_legacy(NULL, NR_IRQS - 1, 1, 0,
 158                                &xtensa_mx_irq_domain_ops,
 159                                &xtensa_mx_irq_chip);
 160        irq_set_default_host(root_domain);
 161        secondary_init_irq();
 162        return 0;
 163}
 164
 165static int __init xtensa_mx_init(struct device_node *np,
 166                struct device_node *interrupt_parent)
 167{
 168        struct irq_domain *root_domain =
 169                irq_domain_add_linear(np, NR_IRQS, &xtensa_mx_irq_domain_ops,
 170                                &xtensa_mx_irq_chip);
 171        irq_set_default_host(root_domain);
 172        secondary_init_irq();
 173        return 0;
 174}
 175IRQCHIP_DECLARE(xtensa_mx_irq_chip, "cdns,xtensa-mx", xtensa_mx_init);
 176