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/of.h>
  15
  16#include <asm/mxregs.h>
  17
  18#include "irqchip.h"
  19
  20#define HW_IRQ_IPI_COUNT 2
  21#define HW_IRQ_MX_BASE 2
  22#define HW_IRQ_EXTERN_BASE 3
  23
  24static DEFINE_PER_CPU(unsigned int, cached_irq_mask);
  25
  26static int xtensa_mx_irq_map(struct irq_domain *d, unsigned int irq,
  27                irq_hw_number_t hw)
  28{
  29        if (hw < HW_IRQ_IPI_COUNT) {
  30                struct irq_chip *irq_chip = d->host_data;
  31                irq_set_chip_and_handler_name(irq, irq_chip,
  32                                handle_percpu_irq, "ipi");
  33                irq_set_status_flags(irq, IRQ_LEVEL);
  34                return 0;
  35        }
  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        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                set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
  76                                        HW_IRQ_MX_BASE), MIENG);
  77        } else {
  78                mask = __this_cpu_read(cached_irq_mask) & ~mask;
  79                __this_cpu_write(cached_irq_mask, mask);
  80                set_sr(mask, intenable);
  81        }
  82}
  83
  84static void xtensa_mx_irq_unmask(struct irq_data *d)
  85{
  86        unsigned int mask = 1u << d->hwirq;
  87
  88        if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
  89                                XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
  90                set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
  91                                        HW_IRQ_MX_BASE), MIENGSET);
  92        } else {
  93                mask |= __this_cpu_read(cached_irq_mask);
  94                __this_cpu_write(cached_irq_mask, mask);
  95                set_sr(mask, intenable);
  96        }
  97}
  98
  99static void xtensa_mx_irq_enable(struct irq_data *d)
 100{
 101        variant_irq_enable(d->hwirq);
 102        xtensa_mx_irq_unmask(d);
 103}
 104
 105static void xtensa_mx_irq_disable(struct irq_data *d)
 106{
 107        xtensa_mx_irq_mask(d);
 108        variant_irq_disable(d->hwirq);
 109}
 110
 111static void xtensa_mx_irq_ack(struct irq_data *d)
 112{
 113        set_sr(1 << d->hwirq, intclear);
 114}
 115
 116static int xtensa_mx_irq_retrigger(struct irq_data *d)
 117{
 118        set_sr(1 << d->hwirq, intset);
 119        return 1;
 120}
 121
 122static int xtensa_mx_irq_set_affinity(struct irq_data *d,
 123                const struct cpumask *dest, bool force)
 124{
 125        unsigned mask = 1u << cpumask_any_and(dest, cpu_online_mask);
 126
 127        set_er(mask, MIROUT(d->hwirq - HW_IRQ_MX_BASE));
 128        return 0;
 129
 130}
 131
 132static struct irq_chip xtensa_mx_irq_chip = {
 133        .name           = "xtensa-mx",
 134        .irq_enable     = xtensa_mx_irq_enable,
 135        .irq_disable    = xtensa_mx_irq_disable,
 136        .irq_mask       = xtensa_mx_irq_mask,
 137        .irq_unmask     = xtensa_mx_irq_unmask,
 138        .irq_ack        = xtensa_mx_irq_ack,
 139        .irq_retrigger  = xtensa_mx_irq_retrigger,
 140        .irq_set_affinity = xtensa_mx_irq_set_affinity,
 141};
 142
 143int __init xtensa_mx_init_legacy(struct device_node *interrupt_parent)
 144{
 145        struct irq_domain *root_domain =
 146                irq_domain_add_legacy(NULL, NR_IRQS, 0, 0,
 147                                &xtensa_mx_irq_domain_ops,
 148                                &xtensa_mx_irq_chip);
 149        irq_set_default_host(root_domain);
 150        secondary_init_irq();
 151        return 0;
 152}
 153
 154static int __init xtensa_mx_init(struct device_node *np,
 155                struct device_node *interrupt_parent)
 156{
 157        struct irq_domain *root_domain =
 158                irq_domain_add_linear(np, NR_IRQS, &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}
 164IRQCHIP_DECLARE(xtensa_mx_irq_chip, "cdns,xtensa-mx", xtensa_mx_init);
 165