drivers/irqchip/irq-sni-exiu.c

   1 /*
   2  * Driver for Socionext External Interrupt Unit (EXIU)
   3  *
   4  * Copyright (c) 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
   5  *
   6  * Based on irq-tegra.c:
   7  *   Copyright (C) 2011 Google, Inc.
   8  *   Copyright (C) 2010,2013, NVIDIA Corporation
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/irq.h>
  18 #include <linux/irqchip.h>
  19 #include <linux/irqdomain.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_irq.h>
  23
  24 #include <dt-bindings/interrupt-controller/arm-gic.h>
  25
  26 #define NUM_IRQS        32
  27
  28 #define EIMASK          0x00
  29 #define EISRCSEL        0x04
  30 #define EIREQSTA        0x08
  31 #define EIRAWREQSTA     0x0C
  32 #define EIREQCLR        0x10
  33 #define EILVL           0x14
  34 #define EIEDG           0x18
  35 #define EISIR           0x1C
  36
  37 struct exiu_irq_data {
  38         void __iomem    *base;
  39         u32             spi_base;
  40 };
  41
  42 static void exiu_irq_eoi(struct irq_data *d)
  43 {
  44         struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
  45
  46         writel(BIT(d->hwirq), data->base + EIREQCLR);
  47         irq_chip_eoi_parent(d);
  48 }
  49
  50 static void exiu_irq_mask(struct irq_data *d)
  51 {
  52         struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
  53         u32 val;
  54
  55         val = readl_relaxed(data->base + EIMASK) | BIT(d->hwirq);
  56         writel_relaxed(val, data->base + EIMASK);
  57         irq_chip_mask_parent(d);
  58 }
  59
  60 static void exiu_irq_unmask(struct irq_data *d)
  61 {
  62         struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
  63         u32 val;
  64
  65         val = readl_relaxed(data->base + EIMASK) & ~BIT(d->hwirq);
  66         writel_relaxed(val, data->base + EIMASK);
  67         irq_chip_unmask_parent(d);
  68 }
  69
  70 static void exiu_irq_enable(struct irq_data *d)
  71 {
  72         struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
  73         u32 val;
  74
  75         /* clear interrupts that were latched while disabled */
  76         writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR);
  77
  78         val = readl_relaxed(data->base + EIMASK) & ~BIT(d->hwirq);
  79         writel_relaxed(val, data->base + EIMASK);
  80         irq_chip_enable_parent(d);
  81 }
  82
  83 static int exiu_irq_set_type(struct irq_data *d, unsigned int type)
  84 {
  85         struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
  86         u32 val;
  87
  88         val = readl_relaxed(data->base + EILVL);
  89         if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
  90                 val |= BIT(d->hwirq);
  91         else
  92                 val &= ~BIT(d->hwirq);
  93         writel_relaxed(val, data->base + EILVL);
  94
  95         val = readl_relaxed(data->base + EIEDG);
  96         if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
  97                 val &= ~BIT(d->hwirq);
  98         else
  99                 val |= BIT(d->hwirq);
 100         writel_relaxed(val, data->base + EIEDG);
 101
 102         writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR);
 103
 104         return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
 105 }
 106
 107 static struct irq_chip exiu_irq_chip = {
 108         .name                   = "EXIU",
 109         .irq_eoi                = exiu_irq_eoi,
 110         .irq_enable             = exiu_irq_enable,
 111         .irq_mask               = exiu_irq_mask,
 112         .irq_unmask             = exiu_irq_unmask,
 113         .irq_set_type           = exiu_irq_set_type,
 114         .irq_set_affinity       = irq_chip_set_affinity_parent,
 115         .flags                  = IRQCHIP_SET_TYPE_MASKED |
 116                                   IRQCHIP_SKIP_SET_WAKE |
 117                                   IRQCHIP_EOI_THREADED |
 118                                   IRQCHIP_MASK_ON_SUSPEND,
 119 };
 120
 121 static int exiu_domain_translate(struct irq_domain *domain,
 122                                  struct irq_fwspec *fwspec,
 123                                  unsigned long *hwirq,
 124                                  unsigned int *type)
 125 {
 126         struct exiu_irq_data *info = domain->host_data;
 127
 128         if (is_of_node(fwspec->fwnode)) {
 129                 if (fwspec->param_count != 3)
 130                         return -EINVAL;
 131
 132                 if (fwspec->param[0] != GIC_SPI)
 133                         return -EINVAL; /* No PPI should point to this domain */
 134
 135                 *hwirq = fwspec->param[1] - info->spi_base;
 136                 *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
 137                 return 0;
 138         }
 139         return -EINVAL;
 140 }
 141
 142 static int exiu_domain_alloc(struct irq_domain *dom, unsigned int virq,
 143                              unsigned int nr_irqs, void *data)
 144 {
 145         struct irq_fwspec *fwspec = data;
 146         struct irq_fwspec parent_fwspec;
 147         struct exiu_irq_data *info = dom->host_data;
 148         irq_hw_number_t hwirq;
 149
 150         if (fwspec->param_count != 3)
 151                 return -EINVAL; /* Not GIC compliant */
 152         if (fwspec->param[0] != GIC_SPI)
 153                 return -EINVAL; /* No PPI should point to this domain */
 154
 155         WARN_ON(nr_irqs != 1);
 156         hwirq = fwspec->param[1] - info->spi_base;
 157         irq_domain_set_hwirq_and_chip(dom, virq, hwirq, &exiu_irq_chip, info);
 158
 159         parent_fwspec = *fwspec;
 160         parent_fwspec.fwnode = dom->parent->fwnode;
 161         return irq_domain_alloc_irqs_parent(dom, virq, nr_irqs, &parent_fwspec);
 162 }
 163
 164 static const struct irq_domain_ops exiu_domain_ops = {
 165         .translate      = exiu_domain_translate,
 166         .alloc          = exiu_domain_alloc,
 167         .free           = irq_domain_free_irqs_common,
 168 };
 169
 170 static int __init exiu_init(struct device_node *node,
 171                             struct device_node *parent)
 172 {
 173         struct irq_domain *parent_domain, *domain;
 174         struct exiu_irq_data *data;
 175         int err;
 176
 177         if (!parent) {
 178                 pr_err("%pOF: no parent, giving up\n", node);
 179                 return -ENODEV;
 180         }
 181
 182         parent_domain = irq_find_host(parent);
 183         if (!parent_domain) {
 184                 pr_err("%pOF: unable to obtain parent domain\n", node);
 185                 return -ENXIO;
 186         }
 187
 188         data = kzalloc(sizeof(*data), GFP_KERNEL);
 189         if (!data)
 190                 return -ENOMEM;
 191
 192         if (of_property_read_u32(node, "socionext,spi-base", &data->spi_base)) {
 193                 pr_err("%pOF: failed to parse 'spi-base' property\n", node);
 194                 err = -ENODEV;
 195                 goto out_free;
 196         }
 197
 198         data->base = of_iomap(node, 0);
 199         if (!data->base) {
 200                 err = -ENODEV;
 201                 goto out_free;
 202         }
 203
 204         /* clear and mask all interrupts */
 205         writel_relaxed(0xFFFFFFFF, data->base + EIREQCLR);
 206         writel_relaxed(0xFFFFFFFF, data->base + EIMASK);
 207
 208         domain = irq_domain_add_hierarchy(parent_domain, 0, NUM_IRQS, node,
 209                                           &exiu_domain_ops, data);
 210         if (!domain) {
 211                 pr_err("%pOF: failed to allocate domain\n", node);
 212                 err = -ENOMEM;
 213                 goto out_unmap;
 214         }
 215
 216         pr_info("%pOF: %d interrupts forwarded to %pOF\n", node, NUM_IRQS,
 217                 parent);
 218
 219         return 0;
 220
 221 out_unmap:
 222         iounmap(data->base);
 223 out_free:
 224         kfree(data);
 225         return err;
 226 }
 227 IRQCHIP_DECLARE(exiu, "socionext,synquacer-exiu", exiu_init);