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/irqdomain.h>
  17 #include <linux/irqchip/chained_irq.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_irq.h>
  20 #include <asm/mach/irq.h>
  21
  22 #ifdef CONFIG_EXYNOS_ATAGS
  23 #include <plat/cpu.h>
  24 #endif
  25
  26 #include "irqchip.h"
  27
  28 #define COMBINER_ENABLE_SET     0x0
  29 #define COMBINER_ENABLE_CLEAR   0x4
  30 #define COMBINER_INT_STATUS     0xC
  31
  32 #define IRQ_IN_COMBINER         8
  33
  34 static DEFINE_SPINLOCK(irq_controller_lock);
  35
  36 struct combiner_chip_data {
  37         unsigned int hwirq_offset;
  38         unsigned int irq_mask;
  39         void __iomem *base;
  40         unsigned int parent_irq;
  41 };
  42
  43 static struct irq_domain *combiner_irq_domain;
  44
  45 static inline void __iomem *combiner_base(struct irq_data *data)
  46 {
  47         struct combiner_chip_data *combiner_data =
  48                 irq_data_get_irq_chip_data(data);
  49
  50         return combiner_data->base;
  51 }
  52
  53 static void combiner_mask_irq(struct irq_data *data)
  54 {
  55         u32 mask = 1 << (data->hwirq % 32);
  56
  57         __raw_writel(mask, combiner_base(data) + COMBINER_ENABLE_CLEAR);
  58 }
  59
  60 static void combiner_unmask_irq(struct irq_data *data)
  61 {
  62         u32 mask = 1 << (data->hwirq % 32);
  63
  64         __raw_writel(mask, combiner_base(data) + COMBINER_ENABLE_SET);
  65 }
  66
  67 static void combiner_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
  68 {
  69         struct combiner_chip_data *chip_data = irq_get_handler_data(irq);
  70         struct irq_chip *chip = irq_get_chip(irq);
  71         unsigned int cascade_irq, combiner_irq;
  72         unsigned long status;
  73
  74         chained_irq_enter(chip, desc);
  75
  76         spin_lock(&irq_controller_lock);
  77         status = __raw_readl(chip_data->base + COMBINER_INT_STATUS);
  78         spin_unlock(&irq_controller_lock);
  79         status &= chip_data->irq_mask;
  80
  81         if (status == 0)
  82                 goto out;
  83
  84         combiner_irq = chip_data->hwirq_offset + __ffs(status);
  85         cascade_irq = irq_find_mapping(combiner_irq_domain, combiner_irq);
  86
  87         if (unlikely(!cascade_irq))
  88                 do_bad_IRQ(irq, desc);
  89         else
  90                 generic_handle_irq(cascade_irq);
  91
  92  out:
  93         chained_irq_exit(chip, desc);
  94 }
  95
  96 #ifdef CONFIG_SMP
  97 static int combiner_set_affinity(struct irq_data *d,
  98                                  const struct cpumask *mask_val, bool force)
  99 {
 100         struct combiner_chip_data *chip_data = irq_data_get_irq_chip_data(d);
 101         struct irq_chip *chip = irq_get_chip(chip_data->parent_irq);
 102         struct irq_data *data = irq_get_irq_data(chip_data->parent_irq);
 103
 104         if (chip && chip->irq_set_affinity)
 105                 return chip->irq_set_affinity(data, mask_val, force);
 106         else
 107                 return -EINVAL;
 108 }
 109 #endif
 110
 111 static struct irq_chip combiner_chip = {
 112         .name                   = "COMBINER",
 113         .irq_mask               = combiner_mask_irq,
 114         .irq_unmask             = combiner_unmask_irq,
 115 #ifdef CONFIG_SMP
 116         .irq_set_affinity       = combiner_set_affinity,
 117 #endif
 118 };
 119
 120 static void __init combiner_cascade_irq(struct combiner_chip_data *combiner_data,
 121                                         unsigned int irq)
 122 {
 123         if (irq_set_handler_data(irq, combiner_data) != 0)
 124                 BUG();
 125         irq_set_chained_handler(irq, combiner_handle_cascade_irq);
 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         __raw_writel(combiner_data->irq_mask, base + COMBINER_ENABLE_CLEAR);
 139 }
 140
 141 #ifdef CONFIG_OF
 142 static int combiner_irq_domain_xlate(struct irq_domain *d,
 143                                      struct device_node *controller,
 144                                      const u32 *intspec, unsigned int intsize,
 145                                      unsigned long *out_hwirq,
 146                                      unsigned int *out_type)
 147 {
 148         if (d->of_node != controller)
 149                 return -EINVAL;
 150
 151         if (intsize < 2)
 152                 return -EINVAL;
 153
 154         *out_hwirq = intspec[0] * IRQ_IN_COMBINER + intspec[1];
 155         *out_type = 0;
 156
 157         return 0;
 158 }
 159 #else
 160 static int combiner_irq_domain_xlate(struct irq_domain *d,
 161                                      struct device_node *controller,
 162                                      const u32 *intspec, unsigned int intsize,
 163                                      unsigned long *out_hwirq,
 164                                      unsigned int *out_type)
 165 {
 166         return -EINVAL;
 167 }
 168 #endif
 169
 170 static int combiner_irq_domain_map(struct irq_domain *d, unsigned int irq,
 171                                    irq_hw_number_t hw)
 172 {
 173         struct combiner_chip_data *combiner_data = d->host_data;
 174
 175         irq_set_chip_and_handler(irq, &combiner_chip, handle_level_irq);
 176         irq_set_chip_data(irq, &combiner_data[hw >> 3]);
 177         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 178
 179         return 0;
 180 }
 181
 182 static struct irq_domain_ops combiner_irq_domain_ops = {
 183         .xlate  = combiner_irq_domain_xlate,
 184         .map    = combiner_irq_domain_map,
 185 };
 186
 187 static unsigned int combiner_lookup_irq(int group)
 188 {
 189 #ifdef CONFIG_EXYNOS_ATAGS
 190         if (group < EXYNOS4210_MAX_COMBINER_NR || soc_is_exynos5250())
 191                 return IRQ_SPI(group);
 192
 193         switch (group) {
 194         case 16:
 195                 return IRQ_SPI(107);
 196         case 17:
 197                 return IRQ_SPI(108);
 198         case 18:
 199                 return IRQ_SPI(48);
 200         case 19:
 201                 return IRQ_SPI(42);
 202         }
 203 #endif
 204         return 0;
 205 }
 206
 207 void __init combiner_init(void __iomem *combiner_base,
 208                           struct device_node *np,
 209                           unsigned int max_nr,
 210                           int irq_base)
 211 {
 212         int i, irq;
 213         unsigned int nr_irq;
 214         struct combiner_chip_data *combiner_data;
 215
 216         nr_irq = max_nr * IRQ_IN_COMBINER;
 217
 218         combiner_data = kcalloc(max_nr, sizeof (*combiner_data), GFP_KERNEL);
 219         if (!combiner_data) {
 220                 pr_warning("%s: could not allocate combiner data\n", __func__);
 221                 return;
 222         }
 223
 224         combiner_irq_domain = irq_domain_add_simple(np, nr_irq, irq_base,
 225                                 &combiner_irq_domain_ops, combiner_data);
 226         if (WARN_ON(!combiner_irq_domain)) {
 227                 pr_warning("%s: irq domain init failed\n", __func__);
 228                 return;
 229         }
 230
 231         for (i = 0; i < max_nr; i++) {
 232 #ifdef CONFIG_OF
 233                 if (np)
 234                         irq = irq_of_parse_and_map(np, i);
 235                 else
 236 #endif
 237                         irq = combiner_lookup_irq(i);
 238
 239                 combiner_init_one(&combiner_data[i], i,
 240                                   combiner_base + (i >> 2) * 0x10, irq);
 241                 combiner_cascade_irq(&combiner_data[i], irq);
 242         }
 243 }
 244
 245 #ifdef CONFIG_OF
 246 static int __init combiner_of_init(struct device_node *np,
 247                                    struct device_node *parent)
 248 {
 249         void __iomem *combiner_base;
 250         unsigned int max_nr = 20;
 251         int irq_base = -1;
 252
 253         combiner_base = of_iomap(np, 0);
 254         if (!combiner_base) {
 255                 pr_err("%s: failed to map combiner registers\n", __func__);
 256                 return -ENXIO;
 257         }
 258
 259         if (of_property_read_u32(np, "samsung,combiner-nr", &max_nr)) {
 260                 pr_info("%s: number of combiners not specified, "
 261                         "setting default as %d.\n",
 262                         __func__, max_nr);
 263         }
 264
 265         /*
 266          * FIXME: This is a hardwired COMBINER_IRQ(0,0). Once all devices
 267          * get their IRQ from DT, remove this in order to get dynamic
 268          * allocation.
 269          */
 270         irq_base = 160;
 271
 272         combiner_init(combiner_base, np, max_nr, irq_base);
 273
 274         return 0;
 275 }
 276 IRQCHIP_DECLARE(exynos4210_combiner, "samsung,exynos4210-combiner",
 277                 combiner_of_init);
 278 #endif