drivers/irqchip/irq-ls-extirq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #define pr_fmt(fmt) "irq-ls-extirq: " fmt
   4
   5 #include <linux/irq.h>
   6 #include <linux/irqchip.h>
   7 #include <linux/irqdomain.h>
   8 #include <linux/of.h>
   9 #include <linux/mfd/syscon.h>
  10 #include <linux/regmap.h>
  11 #include <linux/slab.h>
  12
  13 #include <dt-bindings/interrupt-controller/arm-gic.h>
  14
  15 #define MAXIRQ 12
  16 #define LS1021A_SCFGREVCR 0x200
  17
  18 struct ls_extirq_data {
  19         struct regmap           *syscon;
  20         u32                     intpcr;
  21         bool                    bit_reverse;
  22         u32                     nirq;
  23         struct irq_fwspec       map[MAXIRQ];
  24 };
  25
  26 static int
  27 ls_extirq_set_type(struct irq_data *data, unsigned int type)
  28 {
  29         struct ls_extirq_data *priv = data->chip_data;
  30         irq_hw_number_t hwirq = data->hwirq;
  31         u32 value, mask;
  32
  33         if (priv->bit_reverse)
  34                 mask = 1U << (31 - hwirq);
  35         else
  36                 mask = 1U << hwirq;
  37
  38         switch (type) {
  39         case IRQ_TYPE_LEVEL_LOW:
  40                 type = IRQ_TYPE_LEVEL_HIGH;
  41                 value = mask;
  42                 break;
  43         case IRQ_TYPE_EDGE_FALLING:
  44                 type = IRQ_TYPE_EDGE_RISING;
  45                 value = mask;
  46                 break;
  47         case IRQ_TYPE_LEVEL_HIGH:
  48         case IRQ_TYPE_EDGE_RISING:
  49                 value = 0;
  50                 break;
  51         default:
  52                 return -EINVAL;
  53         }
  54         regmap_update_bits(priv->syscon, priv->intpcr, mask, value);
  55
  56         return irq_chip_set_type_parent(data, type);
  57 }
  58
  59 static struct irq_chip ls_extirq_chip = {
  60         .name                   = "ls-extirq",
  61         .irq_mask               = irq_chip_mask_parent,
  62         .irq_unmask             = irq_chip_unmask_parent,
  63         .irq_eoi                = irq_chip_eoi_parent,
  64         .irq_set_type           = ls_extirq_set_type,
  65         .irq_retrigger          = irq_chip_retrigger_hierarchy,
  66         .irq_set_affinity       = irq_chip_set_affinity_parent,
  67         .flags                  = IRQCHIP_SET_TYPE_MASKED,
  68 };
  69
  70 static int
  71 ls_extirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
  72                        unsigned int nr_irqs, void *arg)
  73 {
  74         struct ls_extirq_data *priv = domain->host_data;
  75         struct irq_fwspec *fwspec = arg;
  76         irq_hw_number_t hwirq;
  77
  78         if (fwspec->param_count != 2)
  79                 return -EINVAL;
  80
  81         hwirq = fwspec->param[0];
  82         if (hwirq >= priv->nirq)
  83                 return -EINVAL;
  84
  85         irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &ls_extirq_chip,
  86                                       priv);
  87
  88         return irq_domain_alloc_irqs_parent(domain, virq, 1, &priv->map[hwirq]);
  89 }
  90
  91 static const struct irq_domain_ops extirq_domain_ops = {
  92         .xlate          = irq_domain_xlate_twocell,
  93         .alloc          = ls_extirq_domain_alloc,
  94         .free           = irq_domain_free_irqs_common,
  95 };
  96
  97 static int
  98 ls_extirq_parse_map(struct ls_extirq_data *priv, struct device_node *node)
  99 {
 100         const __be32 *map;
 101         u32 mapsize;
 102         int ret;
 103
 104         map = of_get_property(node, "interrupt-map", &mapsize);
 105         if (!map)
 106                 return -ENOENT;
 107         if (mapsize % sizeof(*map))
 108                 return -EINVAL;
 109         mapsize /= sizeof(*map);
 110
 111         while (mapsize) {
 112                 struct device_node *ipar;
 113                 u32 hwirq, intsize, j;
 114
 115                 if (mapsize < 3)
 116                         return -EINVAL;
 117                 hwirq = be32_to_cpup(map);
 118                 if (hwirq >= MAXIRQ)
 119                         return -EINVAL;
 120                 priv->nirq = max(priv->nirq, hwirq + 1);
 121
 122                 ipar = of_find_node_by_phandle(be32_to_cpup(map + 2));
 123                 map += 3;
 124                 mapsize -= 3;
 125                 if (!ipar)
 126                         return -EINVAL;
 127                 priv->map[hwirq].fwnode = &ipar->fwnode;
 128                 ret = of_property_read_u32(ipar, "#interrupt-cells", &intsize);
 129                 if (ret)
 130                         return ret;
 131
 132                 if (intsize > mapsize)
 133                         return -EINVAL;
 134
 135                 priv->map[hwirq].param_count = intsize;
 136                 for (j = 0; j < intsize; ++j)
 137                         priv->map[hwirq].param[j] = be32_to_cpup(map++);
 138                 mapsize -= intsize;
 139         }
 140         return 0;
 141 }
 142
 143 static int __init
 144 ls_extirq_of_init(struct device_node *node, struct device_node *parent)
 145 {
 146
 147         struct irq_domain *domain, *parent_domain;
 148         struct ls_extirq_data *priv;
 149         int ret;
 150
 151         parent_domain = irq_find_host(parent);
 152         if (!parent_domain) {
 153                 pr_err("Cannot find parent domain\n");
 154                 return -ENODEV;
 155         }
 156
 157         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 158         if (!priv)
 159                 return -ENOMEM;
 160
 161         priv->syscon = syscon_node_to_regmap(node->parent);
 162         if (IS_ERR(priv->syscon)) {
 163                 ret = PTR_ERR(priv->syscon);
 164                 pr_err("Failed to lookup parent regmap\n");
 165                 goto out;
 166         }
 167         ret = of_property_read_u32(node, "reg", &priv->intpcr);
 168         if (ret) {
 169                 pr_err("Missing INTPCR offset value\n");
 170                 goto out;
 171         }
 172
 173         ret = ls_extirq_parse_map(priv, node);
 174         if (ret)
 175                 goto out;
 176
 177         if (of_device_is_compatible(node, "fsl,ls1021a-extirq")) {
 178                 u32 revcr;
 179
 180                 ret = regmap_read(priv->syscon, LS1021A_SCFGREVCR, &revcr);
 181                 if (ret)
 182                         goto out;
 183                 priv->bit_reverse = (revcr != 0);
 184         }
 185
 186         domain = irq_domain_add_hierarchy(parent_domain, 0, priv->nirq, node,
 187                                           &extirq_domain_ops, priv);
 188         if (!domain)
 189                 ret = -ENOMEM;
 190
 191 out:
 192         if (ret)
 193                 kfree(priv);
 194         return ret;
 195 }
 196
 197 IRQCHIP_DECLARE(ls1021a_extirq, "fsl,ls1021a-extirq", ls_extirq_of_init);