LXR linux/drivers/irqchip/irq-brcmstb-l2.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Generic Broadcom Set Top Box Level 2 Interrupt controller driver
   4 *
   5 * Copyright (C) 2014-2017 Broadcom
   6 */
   7
   8#define pr_fmt(fmt)     KBUILD_MODNAME  ": " fmt
   9
  10#include <linux/init.h>
  11#include <linux/slab.h>
  12#include <linux/module.h>
  13#include <linux/platform_device.h>
  14#include <linux/spinlock.h>
  15#include <linux/of.h>
  16#include <linux/of_irq.h>
  17#include <linux/of_address.h>
  18#include <linux/of_platform.h>
  19#include <linux/interrupt.h>
  20#include <linux/irq.h>
  21#include <linux/io.h>
  22#include <linux/irqdomain.h>
  23#include <linux/irqchip.h>
  24#include <linux/irqchip/chained_irq.h>
  25
  26struct brcmstb_intc_init_params {
  27        irq_flow_handler_t handler;
  28        int cpu_status;
  29        int cpu_clear;
  30        int cpu_mask_status;
  31        int cpu_mask_set;
  32        int cpu_mask_clear;
  33};
  34
  35/* Register offsets in the L2 latched interrupt controller */
  36static const struct brcmstb_intc_init_params l2_edge_intc_init = {
  37        .handler                = handle_edge_irq,
  38        .cpu_status             = 0x00,
  39        .cpu_clear              = 0x08,
  40        .cpu_mask_status        = 0x0c,
  41        .cpu_mask_set           = 0x10,
  42        .cpu_mask_clear         = 0x14
  43};
  44
  45/* Register offsets in the L2 level interrupt controller */
  46static const struct brcmstb_intc_init_params l2_lvl_intc_init = {
  47        .handler                = handle_level_irq,
  48        .cpu_status             = 0x00,
  49        .cpu_clear              = -1, /* Register not present */
  50        .cpu_mask_status        = 0x04,
  51        .cpu_mask_set           = 0x08,
  52        .cpu_mask_clear         = 0x0C
  53};
  54
  55/* L2 intc private data structure */
  56struct brcmstb_l2_intc_data {
  57        struct irq_domain *domain;
  58        struct irq_chip_generic *gc;
  59        int status_offset;
  60        int mask_offset;
  61        bool can_wake;
  62        u32 saved_mask; /* for suspend/resume */
  63};
  64
  65/**
  66 * brcmstb_l2_mask_and_ack - Mask and ack pending interrupt
  67 * @d: irq_data
  68 *
  69 * Chip has separate enable/disable registers instead of a single mask
  70 * register and pending interrupt is acknowledged by setting a bit.
  71 *
  72 * Note: This function is generic and could easily be added to the
  73 * generic irqchip implementation if there ever becomes a will to do so.
  74 * Perhaps with a name like irq_gc_mask_disable_and_ack_set().
  75 *
  76 * e.g.: https://patchwork.kernel.org/patch/9831047/
  77 */
  78static void brcmstb_l2_mask_and_ack(struct irq_data *d)
  79{
  80        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  81        struct irq_chip_type *ct = irq_data_get_chip_type(d);
  82        u32 mask = d->mask;
  83
  84        irq_gc_lock(gc);
  85        irq_reg_writel(gc, mask, ct->regs.disable);
  86        *ct->mask_cache &= ~mask;
  87        irq_reg_writel(gc, mask, ct->regs.ack);
  88        irq_gc_unlock(gc);
  89}
  90
  91static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc)
  92{
  93        struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
  94        struct irq_chip *chip = irq_desc_get_chip(desc);
  95        unsigned int irq;
  96        u32 status;
  97
  98        chained_irq_enter(chip, desc);
  99
 100        status = irq_reg_readl(b->gc, b->status_offset) &
 101                ~(irq_reg_readl(b->gc, b->mask_offset));
 102
 103        if (status == 0) {
 104                raw_spin_lock(&desc->lock);
 105                handle_bad_irq(desc);
 106                raw_spin_unlock(&desc->lock);
 107                goto out;
 108        }
 109
 110        do {
 111                irq = ffs(status) - 1;
 112                status &= ~(1 << irq);
 113                generic_handle_domain_irq(b->domain, irq);
 114        } while (status);
 115out:
 116        chained_irq_exit(chip, desc);
 117}
 118
 119static void brcmstb_l2_intc_suspend(struct irq_data *d)
 120{
 121        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 122        struct irq_chip_type *ct = irq_data_get_chip_type(d);
 123        struct brcmstb_l2_intc_data *b = gc->private;
 124        unsigned long flags;
 125
 126        irq_gc_lock_irqsave(gc, flags);
 127        /* Save the current mask */
 128        b->saved_mask = irq_reg_readl(gc, ct->regs.mask);
 129
 130        if (b->can_wake) {
 131                /* Program the wakeup mask */
 132                irq_reg_writel(gc, ~gc->wake_active, ct->regs.disable);
 133                irq_reg_writel(gc, gc->wake_active, ct->regs.enable);
 134        }
 135        irq_gc_unlock_irqrestore(gc, flags);
 136}
 137
 138static void brcmstb_l2_intc_resume(struct irq_data *d)
 139{
 140        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 141        struct irq_chip_type *ct = irq_data_get_chip_type(d);
 142        struct brcmstb_l2_intc_data *b = gc->private;
 143        unsigned long flags;
 144
 145        irq_gc_lock_irqsave(gc, flags);
 146        if (ct->chip.irq_ack) {
 147                /* Clear unmasked non-wakeup interrupts */
 148                irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active,
 149                                ct->regs.ack);
 150        }
 151
 152        /* Restore the saved mask */
 153        irq_reg_writel(gc, b->saved_mask, ct->regs.disable);
 154        irq_reg_writel(gc, ~b->saved_mask, ct->regs.enable);
 155        irq_gc_unlock_irqrestore(gc, flags);
 156}
 157
 158static int __init brcmstb_l2_intc_of_init(struct device_node *np,
 159                                          struct device_node *parent,
 160                                          const struct brcmstb_intc_init_params
 161                                          *init_params)
 162{
 163        unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 164        struct brcmstb_l2_intc_data *data;
 165        struct irq_chip_type *ct;
 166        int ret;
 167        unsigned int flags;
 168        int parent_irq;
 169        void __iomem *base;
 170
 171        data = kzalloc(sizeof(*data), GFP_KERNEL);
 172        if (!data)
 173                return -ENOMEM;
 174
 175        base = of_iomap(np, 0);
 176        if (!base) {
 177                pr_err("failed to remap intc L2 registers\n");
 178                ret = -ENOMEM;
 179                goto out_free;
 180        }
 181
 182        /* Disable all interrupts by default */
 183        writel(0xffffffff, base + init_params->cpu_mask_set);
 184
 185        /* Wakeup interrupts may be retained from S5 (cold boot) */
 186        data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
 187        if (!data->can_wake && (init_params->cpu_clear >= 0))
 188                writel(0xffffffff, base + init_params->cpu_clear);
 189
 190        parent_irq = irq_of_parse_and_map(np, 0);
 191        if (!parent_irq) {
 192                pr_err("failed to find parent interrupt\n");
 193                ret = -EINVAL;
 194                goto out_unmap;
 195        }
 196
 197        data->domain = irq_domain_add_linear(np, 32,
 198                                &irq_generic_chip_ops, NULL);
 199        if (!data->domain) {
 200                ret = -ENOMEM;
 201                goto out_unmap;
 202        }
 203
 204        /* MIPS chips strapped for BE will automagically configure the
 205         * peripheral registers for CPU-native byte order.
 206         */
 207        flags = 0;
 208        if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 209                flags |= IRQ_GC_BE_IO;
 210
 211        /* Allocate a single Generic IRQ chip for this node */
 212        ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
 213                        np->full_name, init_params->handler, clr, 0, flags);
 214        if (ret) {
 215                pr_err("failed to allocate generic irq chip\n");
 216                goto out_free_domain;
 217        }
 218
 219        /* Set the IRQ chaining logic */
 220        irq_set_chained_handler_and_data(parent_irq,
 221                                         brcmstb_l2_intc_irq_handle, data);
 222
 223        data->gc = irq_get_domain_generic_chip(data->domain, 0);
 224        data->gc->reg_base = base;
 225        data->gc->private = data;
 226        data->status_offset = init_params->cpu_status;
 227        data->mask_offset = init_params->cpu_mask_status;
 228
 229        ct = data->gc->chip_types;
 230
 231        if (init_params->cpu_clear >= 0) {
 232                ct->regs.ack = init_params->cpu_clear;
 233                ct->chip.irq_ack = irq_gc_ack_set_bit;
 234                ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack;
 235        } else {
 236                /* No Ack - but still slightly more efficient to define this */
 237                ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
 238        }
 239
 240        ct->chip.irq_mask = irq_gc_mask_disable_reg;
 241        ct->regs.disable = init_params->cpu_mask_set;
 242        ct->regs.mask = init_params->cpu_mask_status;
 243
 244        ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
 245        ct->regs.enable = init_params->cpu_mask_clear;
 246
 247        ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
 248        ct->chip.irq_resume = brcmstb_l2_intc_resume;
 249        ct->chip.irq_pm_shutdown = brcmstb_l2_intc_suspend;
 250
 251        if (data->can_wake) {
 252                /* This IRQ chip can wake the system, set all child interrupts
 253                 * in wake_enabled mask
 254                 */
 255                data->gc->wake_enabled = 0xffffffff;
 256                ct->chip.irq_set_wake = irq_gc_set_wake;
 257                enable_irq_wake(parent_irq);
 258        }
 259
 260        pr_info("registered L2 intc (%pOF, parent irq: %d)\n", np, parent_irq);
 261
 262        return 0;
 263
 264out_free_domain:
 265        irq_domain_remove(data->domain);
 266out_unmap:
 267        iounmap(base);
 268out_free:
 269        kfree(data);
 270        return ret;
 271}
 272
 273static int __init brcmstb_l2_edge_intc_of_init(struct device_node *np,
 274        struct device_node *parent)
 275{
 276        return brcmstb_l2_intc_of_init(np, parent, &l2_edge_intc_init);
 277}
 278IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_edge_intc_of_init);
 279IRQCHIP_DECLARE(brcmstb_hif_spi_l2_intc, "brcm,hif-spi-l2-intc",
 280                brcmstb_l2_edge_intc_of_init);
 281IRQCHIP_DECLARE(brcmstb_upg_aux_aon_l2_intc, "brcm,upg-aux-aon-l2-intc",
 282                brcmstb_l2_edge_intc_of_init);
 283
 284static int __init brcmstb_l2_lvl_intc_of_init(struct device_node *np,
 285        struct device_node *parent)
 286{
 287        return brcmstb_l2_intc_of_init(np, parent, &l2_lvl_intc_init);
 288}
 289IRQCHIP_DECLARE(bcm7271_l2_intc, "brcm,bcm7271-l2-intc",
 290        brcmstb_l2_lvl_intc_of_init);
 291