drivers/irqchip/exynos-combiner.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * Combiner irqchip for EXYNOS
   7  */
   8 #include <linux/err.h>
   9 #include <linux/export.h>
  10 #include <linux/init.h>
  11 #include <linux/io.h>
  12 #include <linux/slab.h>
  13 #include <linux/syscore_ops.h>
  14 #include <linux/irqdomain.h>
  15 #include <linux/irqchip.h>
  16 #include <linux/irqchip/chained_irq.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_irq.h>
  20
  21 #define COMBINER_ENABLE_SET     0x0
  22 #define COMBINER_ENABLE_CLEAR   0x4
  23 #define COMBINER_INT_STATUS     0xC
  24
  25 #define IRQ_IN_COMBINER         8
  26
  27 static DEFINE_SPINLOCK(irq_controller_lock);
  28
  29 struct combiner_chip_data {
  30         unsigned int hwirq_offset;
  31         unsigned int irq_mask;
  32         void __iomem *base;
  33         unsigned int parent_irq;
  34 #ifdef CONFIG_PM
  35         u32 pm_save;
  36 #endif
  37 };
  38
  39 static struct combiner_chip_data *combiner_data;
  40 static struct irq_domain *combiner_irq_domain;
  41 static unsigned int max_nr = 20;
  42
  43 static inline void __iomem *combiner_base(struct irq_data *data)
  44 {
  45         struct combiner_chip_data *combiner_data =
  46                 irq_data_get_irq_chip_data(data);
  47
  48         return combiner_data->base;
  49 }
  50
  51 static void combiner_mask_irq(struct irq_data *data)
  52 {
  53         u32 mask = 1 << (data->hwirq % 32);
  54
  55         writel_relaxed(mask, combiner_base(data) + COMBINER_ENABLE_CLEAR);
  56 }
  57
  58 static void combiner_unmask_irq(struct irq_data *data)
  59 {
  60         u32 mask = 1 << (data->hwirq % 32);
  61
  62         writel_relaxed(mask, combiner_base(data) + COMBINER_ENABLE_SET);
  63 }
  64
  65 static void combiner_handle_cascade_irq(struct irq_desc *desc)
  66 {
  67         struct combiner_chip_data *chip_data = irq_desc_get_handler_data(desc);
  68         struct irq_chip *chip = irq_desc_get_chip(desc);
  69         unsigned int cascade_irq, combiner_irq;
  70         unsigned long status;
  71
  72         chained_irq_enter(chip, desc);
  73
  74         spin_lock(&irq_controller_lock);
  75         status = readl_relaxed(chip_data->base + COMBINER_INT_STATUS);
  76         spin_unlock(&irq_controller_lock);
  77         status &= chip_data->irq_mask;
  78
  79         if (status == 0)
  80                 goto out;
  81
  82         combiner_irq = chip_data->hwirq_offset + __ffs(status);
  83         cascade_irq = irq_find_mapping(combiner_irq_domain, combiner_irq);
  84
  85         if (unlikely(!cascade_irq))
  86                 handle_bad_irq(desc);
  87         else
  88                 generic_handle_irq(cascade_irq);
  89
  90  out:
  91         chained_irq_exit(chip, desc);
  92 }
  93
  94 #ifdef CONFIG_SMP
  95 static int combiner_set_affinity(struct irq_data *d,
  96                                  const struct cpumask *mask_val, bool force)
  97 {
  98         struct combiner_chip_data *chip_data = irq_data_get_irq_chip_data(d);
  99         struct irq_chip *chip = irq_get_chip(chip_data->parent_irq);
 100         struct irq_data *data = irq_get_irq_data(chip_data->parent_irq);
 101
 102         if (chip && chip->irq_set_affinity)
 103                 return chip->irq_set_affinity(data, mask_val, force);
 104         else
 105                 return -EINVAL;
 106 }
 107 #endif
 108
 109 static struct irq_chip combiner_chip = {
 110         .name                   = "COMBINER",
 111         .irq_mask               = combiner_mask_irq,
 112         .irq_unmask             = combiner_unmask_irq,
 113 #ifdef CONFIG_SMP
 114         .irq_set_affinity       = combiner_set_affinity,
 115 #endif
 116 };
 117
 118 static void __init combiner_cascade_irq(struct combiner_chip_data *combiner_data,
 119                                         unsigned int irq)
 120 {
 121         irq_set_chained_handler_and_data(irq, combiner_handle_cascade_irq,
 122                                          combiner_data);
 123 }
 124
 125 static void __init combiner_init_one(struct combiner_chip_data *combiner_data,
 126                                      unsigned int combiner_nr,
 127                                      void __iomem *base, unsigned int irq)
 128 {
 129         combiner_data->base = base;
 130         combiner_data->hwirq_offset = (combiner_nr & ~3) * IRQ_IN_COMBINER;
 131         combiner_data->irq_mask = 0xff << ((combiner_nr % 4) << 3);
 132         combiner_data->parent_irq = irq;
 133
 134         /* Disable all interrupts */
 135         writel_relaxed(combiner_data->irq_mask, base + COMBINER_ENABLE_CLEAR);
 136 }
 137
 138 static int combiner_irq_domain_xlate(struct irq_domain *d,
 139                                      struct device_node *controller,
 140                                      const u32 *intspec, unsigned int intsize,
 141                                      unsigned long *out_hwirq,
 142                                      unsigned int *out_type)
 143 {
 144         if (irq_domain_get_of_node(d) != controller)
 145                 return -EINVAL;
 146
 147         if (intsize < 2)
 148                 return -EINVAL;
 149
 150         *out_hwirq = intspec[0] * IRQ_IN_COMBINER + intspec[1];
 151         *out_type = 0;
 152
 153         return 0;
 154 }
 155
 156 static int combiner_irq_domain_map(struct irq_domain *d, unsigned int irq,
 157                                    irq_hw_number_t hw)
 158 {
 159         struct combiner_chip_data *combiner_data = d->host_data;
 160
 161         irq_set_chip_and_handler(irq, &combiner_chip, handle_level_irq);
 162         irq_set_chip_data(irq, &combiner_data[hw >> 3]);
 163         irq_set_probe(irq);
 164
 165         return 0;
 166 }
 167
 168 static const struct irq_domain_ops combiner_irq_domain_ops = {
 169         .xlate  = combiner_irq_domain_xlate,
 170         .map    = combiner_irq_domain_map,
 171 };
 172
 173 static void __init combiner_init(void __iomem *combiner_base,
 174                                  struct device_node *np)
 175 {
 176         int i, irq;
 177         unsigned int nr_irq;
 178
 179         nr_irq = max_nr * IRQ_IN_COMBINER;
 180
 181         combiner_data = kcalloc(max_nr, sizeof (*combiner_data), GFP_KERNEL);
 182         if (!combiner_data) {
 183                 pr_warn("%s: could not allocate combiner data\n", __func__);
 184                 return;
 185         }
 186
 187         combiner_irq_domain = irq_domain_add_linear(np, nr_irq,
 188                                 &combiner_irq_domain_ops, combiner_data);
 189         if (WARN_ON(!combiner_irq_domain)) {
 190                 pr_warn("%s: irq domain init failed\n", __func__);
 191                 return;
 192         }
 193
 194         for (i = 0; i < max_nr; i++) {
 195                 irq = irq_of_parse_and_map(np, i);
 196
 197                 combiner_init_one(&combiner_data[i], i,
 198                                   combiner_base + (i >> 2) * 0x10, irq);
 199                 combiner_cascade_irq(&combiner_data[i], irq);
 200         }
 201 }
 202
 203 #ifdef CONFIG_PM
 204
 205 /**
 206  * combiner_suspend - save interrupt combiner state before suspend
 207  *
 208  * Save the interrupt enable set register for all combiner groups since
 209  * the state is lost when the system enters into a sleep state.
 210  *
 211  */
 212 static int combiner_suspend(void)
 213 {
 214         int i;
 215
 216         for (i = 0; i < max_nr; i++)
 217                 combiner_data[i].pm_save =
 218                         readl_relaxed(combiner_data[i].base + COMBINER_ENABLE_SET);
 219
 220         return 0;
 221 }
 222
 223 /**
 224  * combiner_resume - restore interrupt combiner state after resume
 225  *
 226  * Restore the interrupt enable set register for all combiner groups since
 227  * the state is lost when the system enters into a sleep state on suspend.
 228  *
 229  */
 230 static void combiner_resume(void)
 231 {
 232         int i;
 233
 234         for (i = 0; i < max_nr; i++) {
 235                 writel_relaxed(combiner_data[i].irq_mask,
 236                              combiner_data[i].base + COMBINER_ENABLE_CLEAR);
 237                 writel_relaxed(combiner_data[i].pm_save,
 238                              combiner_data[i].base + COMBINER_ENABLE_SET);
 239         }
 240 }
 241
 242 #else
 243 #define combiner_suspend        NULL
 244 #define combiner_resume         NULL
 245 #endif
 246
 247 static struct syscore_ops combiner_syscore_ops = {
 248         .suspend        = combiner_suspend,
 249         .resume         = combiner_resume,
 250 };
 251
 252 static int __init combiner_of_init(struct device_node *np,
 253                                    struct device_node *parent)
 254 {
 255         void __iomem *combiner_base;
 256
 257         combiner_base = of_iomap(np, 0);
 258         if (!combiner_base) {
 259                 pr_err("%s: failed to map combiner registers\n", __func__);
 260                 return -ENXIO;
 261         }
 262
 263         if (of_property_read_u32(np, "samsung,combiner-nr", &max_nr)) {
 264                 pr_info("%s: number of combiners not specified, "
 265                         "setting default as %d.\n",
 266                         __func__, max_nr);
 267         }
 268
 269         combiner_init(combiner_base, np);
 270
 271         register_syscore_ops(&combiner_syscore_ops);
 272
 273         return 0;
 274 }
 275 IRQCHIP_DECLARE(exynos4210_combiner, "samsung,exynos4210-combiner",
 276                 combiner_of_init);