linux/drivers/irqchip/irq-mst-intc.c
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   1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2/*
   3 * Copyright (c) 2020 MediaTek Inc.
   4 * Author Mark-PK Tsai <mark-pk.tsai@mediatek.com>
   5 */
   6#include <linux/interrupt.h>
   7#include <linux/io.h>
   8#include <linux/irq.h>
   9#include <linux/irqchip.h>
  10#include <linux/irqdomain.h>
  11#include <linux/of.h>
  12#include <linux/of_address.h>
  13#include <linux/of_irq.h>
  14#include <linux/slab.h>
  15#include <linux/spinlock.h>
  16#include <linux/syscore_ops.h>
  17
  18#define MST_INTC_MAX_IRQS       64
  19
  20#define INTC_MASK               0x0
  21#define INTC_REV_POLARITY       0x10
  22#define INTC_EOI                0x20
  23
  24#ifdef CONFIG_PM_SLEEP
  25static LIST_HEAD(mst_intc_list);
  26#endif
  27
  28struct mst_intc_chip_data {
  29        raw_spinlock_t  lock;
  30        unsigned int    irq_start, nr_irqs;
  31        void __iomem    *base;
  32        bool            no_eoi;
  33#ifdef CONFIG_PM_SLEEP
  34        struct list_head entry;
  35        u16 saved_polarity_conf[DIV_ROUND_UP(MST_INTC_MAX_IRQS, 16)];
  36#endif
  37};
  38
  39static void mst_set_irq(struct irq_data *d, u32 offset)
  40{
  41        irq_hw_number_t hwirq = irqd_to_hwirq(d);
  42        struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d);
  43        u16 val, mask;
  44        unsigned long flags;
  45
  46        mask = 1 << (hwirq % 16);
  47        offset += (hwirq / 16) * 4;
  48
  49        raw_spin_lock_irqsave(&cd->lock, flags);
  50        val = readw_relaxed(cd->base + offset) | mask;
  51        writew_relaxed(val, cd->base + offset);
  52        raw_spin_unlock_irqrestore(&cd->lock, flags);
  53}
  54
  55static void mst_clear_irq(struct irq_data *d, u32 offset)
  56{
  57        irq_hw_number_t hwirq = irqd_to_hwirq(d);
  58        struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d);
  59        u16 val, mask;
  60        unsigned long flags;
  61
  62        mask = 1 << (hwirq % 16);
  63        offset += (hwirq / 16) * 4;
  64
  65        raw_spin_lock_irqsave(&cd->lock, flags);
  66        val = readw_relaxed(cd->base + offset) & ~mask;
  67        writew_relaxed(val, cd->base + offset);
  68        raw_spin_unlock_irqrestore(&cd->lock, flags);
  69}
  70
  71static void mst_intc_mask_irq(struct irq_data *d)
  72{
  73        mst_set_irq(d, INTC_MASK);
  74        irq_chip_mask_parent(d);
  75}
  76
  77static void mst_intc_unmask_irq(struct irq_data *d)
  78{
  79        mst_clear_irq(d, INTC_MASK);
  80        irq_chip_unmask_parent(d);
  81}
  82
  83static void mst_intc_eoi_irq(struct irq_data *d)
  84{
  85        struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d);
  86
  87        if (!cd->no_eoi)
  88                mst_set_irq(d, INTC_EOI);
  89
  90        irq_chip_eoi_parent(d);
  91}
  92
  93static int mst_irq_chip_set_type(struct irq_data *data, unsigned int type)
  94{
  95        switch (type) {
  96        case IRQ_TYPE_LEVEL_LOW:
  97        case IRQ_TYPE_EDGE_FALLING:
  98                mst_set_irq(data, INTC_REV_POLARITY);
  99                break;
 100        case IRQ_TYPE_LEVEL_HIGH:
 101        case IRQ_TYPE_EDGE_RISING:
 102                mst_clear_irq(data, INTC_REV_POLARITY);
 103                break;
 104        default:
 105                return -EINVAL;
 106        }
 107
 108        return irq_chip_set_type_parent(data, IRQ_TYPE_LEVEL_HIGH);
 109}
 110
 111static struct irq_chip mst_intc_chip = {
 112        .name                   = "mst-intc",
 113        .irq_mask               = mst_intc_mask_irq,
 114        .irq_unmask             = mst_intc_unmask_irq,
 115        .irq_eoi                = mst_intc_eoi_irq,
 116        .irq_get_irqchip_state  = irq_chip_get_parent_state,
 117        .irq_set_irqchip_state  = irq_chip_set_parent_state,
 118        .irq_set_affinity       = irq_chip_set_affinity_parent,
 119        .irq_set_vcpu_affinity  = irq_chip_set_vcpu_affinity_parent,
 120        .irq_set_type           = mst_irq_chip_set_type,
 121        .irq_retrigger          = irq_chip_retrigger_hierarchy,
 122        .flags                  = IRQCHIP_SET_TYPE_MASKED |
 123                                  IRQCHIP_SKIP_SET_WAKE |
 124                                  IRQCHIP_MASK_ON_SUSPEND,
 125};
 126
 127#ifdef CONFIG_PM_SLEEP
 128static void mst_intc_polarity_save(struct mst_intc_chip_data *cd)
 129{
 130        int i;
 131        void __iomem *addr = cd->base + INTC_REV_POLARITY;
 132
 133        for (i = 0; i < DIV_ROUND_UP(cd->nr_irqs, 16); i++)
 134                cd->saved_polarity_conf[i] = readw_relaxed(addr + i * 4);
 135}
 136
 137static void mst_intc_polarity_restore(struct mst_intc_chip_data *cd)
 138{
 139        int i;
 140        void __iomem *addr = cd->base + INTC_REV_POLARITY;
 141
 142        for (i = 0; i < DIV_ROUND_UP(cd->nr_irqs, 16); i++)
 143                writew_relaxed(cd->saved_polarity_conf[i], addr + i * 4);
 144}
 145
 146static void mst_irq_resume(void)
 147{
 148        struct mst_intc_chip_data *cd;
 149
 150        list_for_each_entry(cd, &mst_intc_list, entry)
 151                mst_intc_polarity_restore(cd);
 152}
 153
 154static int mst_irq_suspend(void)
 155{
 156        struct mst_intc_chip_data *cd;
 157
 158        list_for_each_entry(cd, &mst_intc_list, entry)
 159                mst_intc_polarity_save(cd);
 160        return 0;
 161}
 162
 163static struct syscore_ops mst_irq_syscore_ops = {
 164        .suspend        = mst_irq_suspend,
 165        .resume         = mst_irq_resume,
 166};
 167
 168static int __init mst_irq_pm_init(void)
 169{
 170        register_syscore_ops(&mst_irq_syscore_ops);
 171        return 0;
 172}
 173late_initcall(mst_irq_pm_init);
 174#endif
 175
 176static int mst_intc_domain_translate(struct irq_domain *d,
 177                                     struct irq_fwspec *fwspec,
 178                                     unsigned long *hwirq,
 179                                     unsigned int *type)
 180{
 181        struct mst_intc_chip_data *cd = d->host_data;
 182
 183        if (is_of_node(fwspec->fwnode)) {
 184                if (fwspec->param_count != 3)
 185                        return -EINVAL;
 186
 187                /* No PPI should point to this domain */
 188                if (fwspec->param[0] != 0)
 189                        return -EINVAL;
 190
 191                if (fwspec->param[1] >= cd->nr_irqs)
 192                        return -EINVAL;
 193
 194                *hwirq = fwspec->param[1];
 195                *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
 196                return 0;
 197        }
 198
 199        return -EINVAL;
 200}
 201
 202static int mst_intc_domain_alloc(struct irq_domain *domain, unsigned int virq,
 203                                 unsigned int nr_irqs, void *data)
 204{
 205        int i;
 206        irq_hw_number_t hwirq;
 207        struct irq_fwspec parent_fwspec, *fwspec = data;
 208        struct mst_intc_chip_data *cd = domain->host_data;
 209
 210        /* Not GIC compliant */
 211        if (fwspec->param_count != 3)
 212                return -EINVAL;
 213
 214        /* No PPI should point to this domain */
 215        if (fwspec->param[0])
 216                return -EINVAL;
 217
 218        hwirq = fwspec->param[1];
 219        for (i = 0; i < nr_irqs; i++)
 220                irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
 221                                              &mst_intc_chip,
 222                                              domain->host_data);
 223
 224        parent_fwspec = *fwspec;
 225        parent_fwspec.fwnode = domain->parent->fwnode;
 226        parent_fwspec.param[1] = cd->irq_start + hwirq;
 227
 228        /*
 229         * mst-intc latch the interrupt request if it's edge triggered,
 230         * so the output signal to parent GIC is always level sensitive.
 231         * And if the irq signal is active low, configure it to active high
 232         * to meet GIC SPI spec in mst_irq_chip_set_type via REV_POLARITY bit.
 233         */
 234        parent_fwspec.param[2] = IRQ_TYPE_LEVEL_HIGH;
 235
 236        return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &parent_fwspec);
 237}
 238
 239static const struct irq_domain_ops mst_intc_domain_ops = {
 240        .translate      = mst_intc_domain_translate,
 241        .alloc          = mst_intc_domain_alloc,
 242        .free           = irq_domain_free_irqs_common,
 243};
 244
 245static int __init mst_intc_of_init(struct device_node *dn,
 246                                   struct device_node *parent)
 247{
 248        struct irq_domain *domain, *domain_parent;
 249        struct mst_intc_chip_data *cd;
 250        u32 irq_start, irq_end;
 251
 252        domain_parent = irq_find_host(parent);
 253        if (!domain_parent) {
 254                pr_err("mst-intc: interrupt-parent not found\n");
 255                return -EINVAL;
 256        }
 257
 258        if (of_property_read_u32_index(dn, "mstar,irqs-map-range", 0, &irq_start) ||
 259            of_property_read_u32_index(dn, "mstar,irqs-map-range", 1, &irq_end))
 260                return -EINVAL;
 261
 262        cd = kzalloc(sizeof(*cd), GFP_KERNEL);
 263        if (!cd)
 264                return -ENOMEM;
 265
 266        cd->base = of_iomap(dn, 0);
 267        if (!cd->base) {
 268                kfree(cd);
 269                return -ENOMEM;
 270        }
 271
 272        cd->no_eoi = of_property_read_bool(dn, "mstar,intc-no-eoi");
 273        raw_spin_lock_init(&cd->lock);
 274        cd->irq_start = irq_start;
 275        cd->nr_irqs = irq_end - irq_start + 1;
 276        domain = irq_domain_add_hierarchy(domain_parent, 0, cd->nr_irqs, dn,
 277                                          &mst_intc_domain_ops, cd);
 278        if (!domain) {
 279                iounmap(cd->base);
 280                kfree(cd);
 281                return -ENOMEM;
 282        }
 283
 284#ifdef CONFIG_PM_SLEEP
 285        INIT_LIST_HEAD(&cd->entry);
 286        list_add_tail(&cd->entry, &mst_intc_list);
 287#endif
 288        return 0;
 289}
 290
 291IRQCHIP_DECLARE(mst_intc, "mstar,mst-intc", mst_intc_of_init);
 292