drivers/irqchip/exynos-combiner.c

   1 /*
   2  * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
   3  *              http://www.samsung.com
   4  *
   5  * Combiner irqchip for EXYNOS
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/err.h>
  12 #include <linux/export.h>
  13 #include <linux/init.h>
  14 #include <linux/io.h>
  15 #include <linux/slab.h>
  16 #include <linux/syscore_ops.h>
  17 #include <linux/irqdomain.h>
  18 #include <linux/irqchip.h>
  19 #include <linux/irqchip/chained_irq.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_irq.h>
  23
  24 #define COMBINER_ENABLE_SET     0x0
  25 #define COMBINER_ENABLE_CLEAR   0x4
  26 #define COMBINER_INT_STATUS     0xC
  27
  28 #define IRQ_IN_COMBINER         8
  29
  30 static DEFINE_SPINLOCK(irq_controller_lock);
  31
  32 struct combiner_chip_data {
  33         unsigned int hwirq_offset;
  34         unsigned int irq_mask;
  35         void __iomem *base;
  36         unsigned int parent_irq;
  37 #ifdef CONFIG_PM
  38         u32 pm_save;
  39 #endif
  40 };
  41
  42 static struct combiner_chip_data *combiner_data;
  43 static struct irq_domain *combiner_irq_domain;
  44 static unsigned int max_nr = 20;
  45
  46 static inline void __iomem *combiner_base(struct irq_data *data)
  47 {
  48         struct combiner_chip_data *combiner_data =
  49                 irq_data_get_irq_chip_data(data);
  50
  51         return combiner_data->base;
  52 }
  53
  54 static void combiner_mask_irq(struct irq_data *data)
  55 {
  56         u32 mask = 1 << (data->hwirq % 32);
  57
  58         writel_relaxed(mask, combiner_base(data) + COMBINER_ENABLE_CLEAR);
  59 }
  60
  61 static void combiner_unmask_irq(struct irq_data *data)
  62 {
  63         u32 mask = 1 << (data->hwirq % 32);
  64
  65         writel_relaxed(mask, combiner_base(data) + COMBINER_ENABLE_SET);
  66 }
  67
  68 static void combiner_handle_cascade_irq(struct irq_desc *desc)
  69 {
  70         struct combiner_chip_data *chip_data = irq_desc_get_handler_data(desc);
  71         struct irq_chip *chip = irq_desc_get_chip(desc);
  72         unsigned int cascade_irq, combiner_irq;
  73         unsigned long status;
  74
  75         chained_irq_enter(chip, desc);
  76
  77         spin_lock(&irq_controller_lock);
  78         status = readl_relaxed(chip_data->base + COMBINER_INT_STATUS);
  79         spin_unlock(&irq_controller_lock);
  80         status &= chip_data->irq_mask;
  81
  82         if (status == 0)
  83                 goto out;
  84
  85         combiner_irq = chip_data->hwirq_offset + __ffs(status);
  86         cascade_irq = irq_find_mapping(combiner_irq_domain, combiner_irq);
  87
  88         if (unlikely(!cascade_irq))
  89                 handle_bad_irq(desc);
  90         else
  91                 generic_handle_irq(cascade_irq);
  92
  93  out:
  94         chained_irq_exit(chip, desc);
  95 }
  96
  97 #ifdef CONFIG_SMP
  98 static int combiner_set_affinity(struct irq_data *d,
  99                                  const struct cpumask *mask_val, bool force)
 100 {
 101         struct combiner_chip_data *chip_data = irq_data_get_irq_chip_data(d);
 102         struct irq_chip *chip = irq_get_chip(chip_data->parent_irq);
 103         struct irq_data *data = irq_get_irq_data(chip_data->parent_irq);
 104
 105         if (chip && chip->irq_set_affinity)
 106                 return chip->irq_set_affinity(data, mask_val, force);
 107         else
 108                 return -EINVAL;
 109 }
 110 #endif
 111
 112 static struct irq_chip combiner_chip = {
 113         .name                   = "COMBINER",
 114         .irq_mask               = combiner_mask_irq,
 115         .irq_unmask             = combiner_unmask_irq,
 116 #ifdef CONFIG_SMP
 117         .irq_set_affinity       = combiner_set_affinity,
 118 #endif
 119 };
 120
 121 static void __init combiner_cascade_irq(struct combiner_chip_data *combiner_data,
 122                                         unsigned int irq)
 123 {
 124         irq_set_chained_handler_and_data(irq, combiner_handle_cascade_irq,
 125                                          combiner_data);
 126 }
 127
 128 static void __init combiner_init_one(struct combiner_chip_data *combiner_data,
 129                                      unsigned int combiner_nr,
 130                                      void __iomem *base, unsigned int irq)
 131 {
 132         combiner_data->base = base;
 133         combiner_data->hwirq_offset = (combiner_nr & ~3) * IRQ_IN_COMBINER;
 134         combiner_data->irq_mask = 0xff << ((combiner_nr % 4) << 3);
 135         combiner_data->parent_irq = irq;
 136
 137         /* Disable all interrupts */
 138         writel_relaxed(combiner_data->irq_mask, base + COMBINER_ENABLE_CLEAR);
 139 }
 140
 141 static int combiner_irq_domain_xlate(struct irq_domain *d,
 142                                      struct device_node *controller,
 143                                      const u32 *intspec, unsigned int intsize,
 144                                      unsigned long *out_hwirq,
 145                                      unsigned int *out_type)
 146 {
 147         if (irq_domain_get_of_node(d) != controller)
 148                 return -EINVAL;
 149
 150         if (intsize < 2)
 151                 return -EINVAL;
 152
 153         *out_hwirq = intspec[0] * IRQ_IN_COMBINER + intspec[1];
 154         *out_type = 0;
 155
 156         return 0;
 157 }
 158
 159 static int combiner_irq_domain_map(struct irq_domain *d, unsigned int irq,
 160                                    irq_hw_number_t hw)
 161 {
 162         struct combiner_chip_data *combiner_data = d->host_data;
 163
 164         irq_set_chip_and_handler(irq, &combiner_chip, handle_level_irq);
 165         irq_set_chip_data(irq, &combiner_data[hw >> 3]);
 166         irq_set_probe(irq);
 167
 168         return 0;
 169 }
 170
 171 static const struct irq_domain_ops combiner_irq_domain_ops = {
 172         .xlate  = combiner_irq_domain_xlate,
 173         .map    = combiner_irq_domain_map,
 174 };
 175
 176 static void __init combiner_init(void __iomem *combiner_base,
 177                                  struct device_node *np)
 178 {
 179         int i, irq;
 180         unsigned int nr_irq;
 181
 182         nr_irq = max_nr * IRQ_IN_COMBINER;
 183
 184         combiner_data = kcalloc(max_nr, sizeof (*combiner_data), GFP_KERNEL);
 185         if (!combiner_data) {
 186                 pr_warn("%s: could not allocate combiner data\n", __func__);
 187                 return;
 188         }
 189
 190         combiner_irq_domain = irq_domain_add_linear(np, nr_irq,
 191                                 &combiner_irq_domain_ops, combiner_data);
 192         if (WARN_ON(!combiner_irq_domain)) {
 193                 pr_warn("%s: irq domain init failed\n", __func__);
 194                 return;
 195         }
 196
 197         for (i = 0; i < max_nr; i++) {
 198                 irq = irq_of_parse_and_map(np, i);
 199
 200                 combiner_init_one(&combiner_data[i], i,
 201                                   combiner_base + (i >> 2) * 0x10, irq);
 202                 combiner_cascade_irq(&combiner_data[i], irq);
 203         }
 204 }
 205
 206 #ifdef CONFIG_PM
 207
 208 /**
 209  * combiner_suspend - save interrupt combiner state before suspend
 210  *
 211  * Save the interrupt enable set register for all combiner groups since
 212  * the state is lost when the system enters into a sleep state.
 213  *
 214  */
 215 static int combiner_suspend(void)
 216 {
 217         int i;
 218
 219         for (i = 0; i < max_nr; i++)
 220                 combiner_data[i].pm_save =
 221                         readl_relaxed(combiner_data[i].base + COMBINER_ENABLE_SET);
 222
 223         return 0;
 224 }
 225
 226 /**
 227  * combiner_resume - restore interrupt combiner state after resume
 228  *
 229  * Restore the interrupt enable set register for all combiner groups since
 230  * the state is lost when the system enters into a sleep state on suspend.
 231  *
 232  */
 233 static void combiner_resume(void)
 234 {
 235         int i;
 236
 237         for (i = 0; i < max_nr; i++) {
 238                 writel_relaxed(combiner_data[i].irq_mask,
 239                              combiner_data[i].base + COMBINER_ENABLE_CLEAR);
 240                 writel_relaxed(combiner_data[i].pm_save,
 241                              combiner_data[i].base + COMBINER_ENABLE_SET);
 242         }
 243 }
 244
 245 #else
 246 #define combiner_suspend        NULL
 247 #define combiner_resume         NULL
 248 #endif
 249
 250 static struct syscore_ops combiner_syscore_ops = {
 251         .suspend        = combiner_suspend,
 252         .resume         = combiner_resume,
 253 };
 254
 255 static int __init combiner_of_init(struct device_node *np,
 256                                    struct device_node *parent)
 257 {
 258         void __iomem *combiner_base;
 259
 260         combiner_base = of_iomap(np, 0);
 261         if (!combiner_base) {
 262                 pr_err("%s: failed to map combiner registers\n", __func__);
 263                 return -ENXIO;
 264         }
 265
 266         if (of_property_read_u32(np, "samsung,combiner-nr", &max_nr)) {
 267                 pr_info("%s: number of combiners not specified, "
 268                         "setting default as %d.\n",
 269                         __func__, max_nr);
 270         }
 271
 272         combiner_init(combiner_base, np);
 273
 274         register_syscore_ops(&combiner_syscore_ops);
 275
 276         return 0;
 277 }
 278 IRQCHIP_DECLARE(exynos4210_combiner, "samsung,exynos4210-combiner",
 279                 combiner_of_init);