drivers/irqchip/irq-mscc-ocelot.c

   1 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
   2 /*
   3  * Microsemi Ocelot IRQ controller driver
   4  *
   5  * Copyright (c) 2017 Microsemi Corporation
   6  */
   7 #include <linux/bitops.h>
   8 #include <linux/irq.h>
   9 #include <linux/of_address.h>
  10 #include <linux/of_irq.h>
  11 #include <linux/irqchip.h>
  12 #include <linux/irqchip/chained_irq.h>
  13 #include <linux/interrupt.h>
  14
  15 #define ICPU_CFG_INTR_INTR_STICKY       0x10
  16 #define ICPU_CFG_INTR_INTR_ENA          0x18
  17 #define ICPU_CFG_INTR_INTR_ENA_CLR      0x1c
  18 #define ICPU_CFG_INTR_INTR_ENA_SET      0x20
  19 #define ICPU_CFG_INTR_DST_INTR_IDENT(x) (0x38 + 0x4 * (x))
  20 #define ICPU_CFG_INTR_INTR_TRIGGER(x)   (0x5c + 0x4 * (x))
  21
  22 #define OCELOT_NR_IRQ 24
  23
  24 static void ocelot_irq_unmask(struct irq_data *data)
  25 {
  26         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
  27         struct irq_chip_type *ct = irq_data_get_chip_type(data);
  28         unsigned int mask = data->mask;
  29         u32 val;
  30
  31         irq_gc_lock(gc);
  32         val = irq_reg_readl(gc, ICPU_CFG_INTR_INTR_TRIGGER(0)) |
  33               irq_reg_readl(gc, ICPU_CFG_INTR_INTR_TRIGGER(1));
  34         if (!(val & mask))
  35                 irq_reg_writel(gc, mask, ICPU_CFG_INTR_INTR_STICKY);
  36
  37         *ct->mask_cache &= ~mask;
  38         irq_reg_writel(gc, mask, ICPU_CFG_INTR_INTR_ENA_SET);
  39         irq_gc_unlock(gc);
  40 }
  41
  42 static void ocelot_irq_handler(struct irq_desc *desc)
  43 {
  44         struct irq_chip *chip = irq_desc_get_chip(desc);
  45         struct irq_domain *d = irq_desc_get_handler_data(desc);
  46         struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, 0);
  47         u32 reg = irq_reg_readl(gc, ICPU_CFG_INTR_DST_INTR_IDENT(0));
  48
  49         chained_irq_enter(chip, desc);
  50
  51         while (reg) {
  52                 u32 hwirq = __fls(reg);
  53
  54                 generic_handle_irq(irq_find_mapping(d, hwirq));
  55                 reg &= ~(BIT(hwirq));
  56         }
  57
  58         chained_irq_exit(chip, desc);
  59 }
  60
  61 static int __init ocelot_irq_init(struct device_node *node,
  62                                   struct device_node *parent)
  63 {
  64         struct irq_domain *domain;
  65         struct irq_chip_generic *gc;
  66         int parent_irq, ret;
  67
  68         parent_irq = irq_of_parse_and_map(node, 0);
  69         if (!parent_irq)
  70                 return -EINVAL;
  71
  72         domain = irq_domain_add_linear(node, OCELOT_NR_IRQ,
  73                                        &irq_generic_chip_ops, NULL);
  74         if (!domain) {
  75                 pr_err("%s: unable to add irq domain\n", node->name);
  76                 return -ENOMEM;
  77         }
  78
  79         ret = irq_alloc_domain_generic_chips(domain, OCELOT_NR_IRQ, 1,
  80                                              "icpu", handle_level_irq,
  81                                              0, 0, 0);
  82         if (ret) {
  83                 pr_err("%s: unable to alloc irq domain gc\n", node->name);
  84                 goto err_domain_remove;
  85         }
  86
  87         gc = irq_get_domain_generic_chip(domain, 0);
  88         gc->reg_base = of_iomap(node, 0);
  89         if (!gc->reg_base) {
  90                 pr_err("%s: unable to map resource\n", node->name);
  91                 ret = -ENOMEM;
  92                 goto err_gc_free;
  93         }
  94
  95         gc->chip_types[0].regs.ack = ICPU_CFG_INTR_INTR_STICKY;
  96         gc->chip_types[0].regs.mask = ICPU_CFG_INTR_INTR_ENA_CLR;
  97         gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
  98         gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
  99         gc->chip_types[0].chip.irq_unmask = ocelot_irq_unmask;
 100
 101         /* Mask and ack all interrupts */
 102         irq_reg_writel(gc, 0, ICPU_CFG_INTR_INTR_ENA);
 103         irq_reg_writel(gc, 0xffffffff, ICPU_CFG_INTR_INTR_STICKY);
 104
 105         irq_set_chained_handler_and_data(parent_irq, ocelot_irq_handler,
 106                                          domain);
 107
 108         return 0;
 109
 110 err_gc_free:
 111         irq_free_generic_chip(gc);
 112
 113 err_domain_remove:
 114         irq_domain_remove(domain);
 115
 116         return ret;
 117 }
 118 IRQCHIP_DECLARE(ocelot_icpu, "mscc,ocelot-icpu-intr", ocelot_irq_init);