drivers/irqchip/irq-bcm7120-l2.c

   1 /*
   2  * Broadcom BCM7120 style Level 2 interrupt controller driver
   3  *
   4  * Copyright (C) 2014 Broadcom Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #define pr_fmt(fmt)     KBUILD_MODNAME  ": " fmt
  12
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/of.h>
  18 #include <linux/of_irq.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/irq.h>
  23 #include <linux/io.h>
  24 #include <linux/irqdomain.h>
  25 #include <linux/reboot.h>
  26 #include <linux/irqchip/chained_irq.h>
  27
  28 #include "irqchip.h"
  29
  30 #include <asm/mach/irq.h>
  31
  32 /* Register offset in the L2 interrupt controller */
  33 #define IRQEN           0x00
  34 #define IRQSTAT         0x04
  35
  36 struct bcm7120_l2_intc_data {
  37         void __iomem *base;
  38         struct irq_domain *domain;
  39         bool can_wake;
  40         u32 irq_fwd_mask;
  41         u32 irq_map_mask;
  42         u32 saved_mask;
  43 };
  44
  45 static void bcm7120_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc)
  46 {
  47         struct bcm7120_l2_intc_data *b = irq_desc_get_handler_data(desc);
  48         struct irq_chip *chip = irq_desc_get_chip(desc);
  49         u32 status;
  50
  51         chained_irq_enter(chip, desc);
  52
  53         status = __raw_readl(b->base + IRQSTAT);
  54
  55         if (status == 0) {
  56                 do_bad_IRQ(irq, desc);
  57                 goto out;
  58         }
  59
  60         do {
  61                 irq = ffs(status) - 1;
  62                 status &= ~(1 << irq);
  63                 generic_handle_irq(irq_find_mapping(b->domain, irq));
  64         } while (status);
  65
  66 out:
  67         chained_irq_exit(chip, desc);
  68 }
  69
  70 static void bcm7120_l2_intc_suspend(struct irq_data *d)
  71 {
  72         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  73         struct bcm7120_l2_intc_data *b = gc->private;
  74         u32 reg;
  75
  76         irq_gc_lock(gc);
  77         /* Save the current mask and the interrupt forward mask */
  78         b->saved_mask = __raw_readl(b->base) | b->irq_fwd_mask;
  79         if (b->can_wake) {
  80                 reg = b->saved_mask | gc->wake_active;
  81                 __raw_writel(reg, b->base);
  82         }
  83         irq_gc_unlock(gc);
  84 }
  85
  86 static void bcm7120_l2_intc_resume(struct irq_data *d)
  87 {
  88         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  89         struct bcm7120_l2_intc_data *b = gc->private;
  90
  91         /* Restore the saved mask */
  92         irq_gc_lock(gc);
  93         __raw_writel(b->saved_mask, b->base);
  94         irq_gc_unlock(gc);
  95 }
  96
  97 static int bcm7120_l2_intc_init_one(struct device_node *dn,
  98                                         struct bcm7120_l2_intc_data *data,
  99                                         int irq, const __be32 *map_mask)
 100 {
 101         int parent_irq;
 102
 103         parent_irq = irq_of_parse_and_map(dn, irq);
 104         if (parent_irq < 0) {
 105                 pr_err("failed to map interrupt %d\n", irq);
 106                 return parent_irq;
 107         }
 108
 109         data->irq_map_mask |= be32_to_cpup(map_mask + irq);
 110
 111         irq_set_handler_data(parent_irq, data);
 112         irq_set_chained_handler(parent_irq, bcm7120_l2_intc_irq_handle);
 113
 114         return 0;
 115 }
 116
 117 int __init bcm7120_l2_intc_of_init(struct device_node *dn,
 118                                         struct device_node *parent)
 119 {
 120         unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 121         struct bcm7120_l2_intc_data *data;
 122         struct irq_chip_generic *gc;
 123         struct irq_chip_type *ct;
 124         const __be32 *map_mask;
 125         int num_parent_irqs;
 126         int ret = 0, len, irq;
 127
 128         data = kzalloc(sizeof(*data), GFP_KERNEL);
 129         if (!data)
 130                 return -ENOMEM;
 131
 132         data->base = of_iomap(dn, 0);
 133         if (!data->base) {
 134                 pr_err("failed to remap intc L2 registers\n");
 135                 ret = -ENOMEM;
 136                 goto out_free;
 137         }
 138
 139         if (of_property_read_u32(dn, "brcm,int-fwd-mask", &data->irq_fwd_mask))
 140                 data->irq_fwd_mask = 0;
 141
 142         /* Enable all interrupt specified in the interrupt forward mask and have
 143          * the other disabled
 144          */
 145         __raw_writel(data->irq_fwd_mask, data->base + IRQEN);
 146
 147         num_parent_irqs = of_irq_count(dn);
 148         if (num_parent_irqs <= 0) {
 149                 pr_err("invalid number of parent interrupts\n");
 150                 ret = -ENOMEM;
 151                 goto out_unmap;
 152         }
 153
 154         map_mask = of_get_property(dn, "brcm,int-map-mask", &len);
 155         if (!map_mask || (len != (sizeof(*map_mask) * num_parent_irqs))) {
 156                 pr_err("invalid brcm,int-map-mask property\n");
 157                 ret = -EINVAL;
 158                 goto out_unmap;
 159         }
 160
 161         for (irq = 0; irq < num_parent_irqs; irq++) {
 162                 ret = bcm7120_l2_intc_init_one(dn, data, irq, map_mask);
 163                 if (ret)
 164                         goto out_unmap;
 165         }
 166
 167         data->domain = irq_domain_add_linear(dn, 32,
 168                                         &irq_generic_chip_ops, NULL);
 169         if (!data->domain) {
 170                 ret = -ENOMEM;
 171                 goto out_unmap;
 172         }
 173
 174         ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
 175                                 dn->full_name, handle_level_irq, clr, 0,
 176                                 IRQ_GC_INIT_MASK_CACHE);
 177         if (ret) {
 178                 pr_err("failed to allocate generic irq chip\n");
 179                 goto out_free_domain;
 180         }
 181
 182         gc = irq_get_domain_generic_chip(data->domain, 0);
 183         gc->unused = 0xfffffff & ~data->irq_map_mask;
 184         gc->reg_base = data->base;
 185         gc->private = data;
 186         ct = gc->chip_types;
 187
 188         ct->regs.mask = IRQEN;
 189         ct->chip.irq_mask = irq_gc_mask_clr_bit;
 190         ct->chip.irq_unmask = irq_gc_mask_set_bit;
 191         ct->chip.irq_ack = irq_gc_noop;
 192         ct->chip.irq_suspend = bcm7120_l2_intc_suspend;
 193         ct->chip.irq_resume = bcm7120_l2_intc_resume;
 194
 195         if (of_property_read_bool(dn, "brcm,irq-can-wake")) {
 196                 data->can_wake = true;
 197                 /* This IRQ chip can wake the system, set all relevant child
 198                  * interupts in wake_enabled mask
 199                  */
 200                 gc->wake_enabled = 0xffffffff;
 201                 gc->wake_enabled &= ~gc->unused;
 202                 ct->chip.irq_set_wake = irq_gc_set_wake;
 203         }
 204
 205         pr_info("registered BCM7120 L2 intc (mem: 0x%p, parent IRQ(s): %d)\n",
 206                         data->base, num_parent_irqs);
 207
 208         return 0;
 209
 210 out_free_domain:
 211         irq_domain_remove(data->domain);
 212 out_unmap:
 213         iounmap(data->base);
 214 out_free:
 215         kfree(data);
 216         return ret;
 217 }
 218 IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,bcm7120-l2-intc",
 219                 bcm7120_l2_intc_of_init);