drivers/irqchip/irq-xtensa-mx.c

   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
  23 static DEFINE_PER_CPU(unsigned int, cached_irq_mask);
  24
  25 static 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  */
  45 static 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
  55 static 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
  60 void 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
  69 static 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
  87 static 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
 105 static void xtensa_mx_irq_enable(struct irq_data *d)
 106 {
 107         xtensa_mx_irq_unmask(d);
 108 }
 109
 110 static void xtensa_mx_irq_disable(struct irq_data *d)
 111 {
 112         xtensa_mx_irq_mask(d);
 113 }
 114
 115 static void xtensa_mx_irq_ack(struct irq_data *d)
 116 {
 117         xtensa_set_sr(1 << d->hwirq, intclear);
 118 }
 119
 120 static 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
 130 static 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
 143 static 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
 154 int __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
 165 static 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 }
 175 IRQCHIP_DECLARE(xtensa_mx_irq_chip, "cdns,xtensa-mx", xtensa_mx_init);