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/interrupt.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_irq.h>
  21
  22 #include "irqchip.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 };
  38
  39 static struct irq_domain *combiner_irq_domain;
  40
  41 static inline void __iomem *combiner_base(struct irq_data *data)
  42 {
  43         struct combiner_chip_data *combiner_data =
  44                 irq_data_get_irq_chip_data(data);
  45
  46         return combiner_data->base;
  47 }
  48
  49 static void combiner_mask_irq(struct irq_data *data)
  50 {
  51         u32 mask = 1 << (data->hwirq % 32);
  52
  53         __raw_writel(mask, combiner_base(data) + COMBINER_ENABLE_CLEAR);
  54 }
  55
  56 static void combiner_unmask_irq(struct irq_data *data)
  57 {
  58         u32 mask = 1 << (data->hwirq % 32);
  59
  60         __raw_writel(mask, combiner_base(data) + COMBINER_ENABLE_SET);
  61 }
  62
  63 static void combiner_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
  64 {
  65         struct combiner_chip_data *chip_data = irq_get_handler_data(irq);
  66         struct irq_chip *chip = irq_get_chip(irq);
  67         unsigned int cascade_irq, combiner_irq;
  68         unsigned long status;
  69
  70         chained_irq_enter(chip, desc);
  71
  72         spin_lock(&irq_controller_lock);
  73         status = __raw_readl(chip_data->base + COMBINER_INT_STATUS);
  74         spin_unlock(&irq_controller_lock);
  75         status &= chip_data->irq_mask;
  76
  77         if (status == 0)
  78                 goto out;
  79
  80         combiner_irq = chip_data->hwirq_offset + __ffs(status);
  81         cascade_irq = irq_find_mapping(combiner_irq_domain, combiner_irq);
  82
  83         if (unlikely(!cascade_irq))
  84                 handle_bad_irq(irq, desc);
  85         else
  86                 generic_handle_irq(cascade_irq);
  87
  88  out:
  89         chained_irq_exit(chip, desc);
  90 }
  91
  92 #ifdef CONFIG_SMP
  93 static int combiner_set_affinity(struct irq_data *d,
  94                                  const struct cpumask *mask_val, bool force)
  95 {
  96         struct combiner_chip_data *chip_data = irq_data_get_irq_chip_data(d);
  97         struct irq_chip *chip = irq_get_chip(chip_data->parent_irq);
  98         struct irq_data *data = irq_get_irq_data(chip_data->parent_irq);
  99
 100         if (chip && chip->irq_set_affinity)
 101                 return chip->irq_set_affinity(data, mask_val, force);
 102         else
 103                 return -EINVAL;
 104 }
 105 #endif
 106
 107 static struct irq_chip combiner_chip = {
 108         .name                   = "COMBINER",
 109         .irq_mask               = combiner_mask_irq,
 110         .irq_unmask             = combiner_unmask_irq,
 111 #ifdef CONFIG_SMP
 112         .irq_set_affinity       = combiner_set_affinity,
 113 #endif
 114 };
 115
 116 static void __init combiner_cascade_irq(struct combiner_chip_data *combiner_data,
 117                                         unsigned int irq)
 118 {
 119         if (irq_set_handler_data(irq, combiner_data) != 0)
 120                 BUG();
 121         irq_set_chained_handler(irq, combiner_handle_cascade_irq);
 122 }
 123
 124 static void __init combiner_init_one(struct combiner_chip_data *combiner_data,
 125                                      unsigned int combiner_nr,
 126                                      void __iomem *base, unsigned int irq)
 127 {
 128         combiner_data->base = base;
 129         combiner_data->hwirq_offset = (combiner_nr & ~3) * IRQ_IN_COMBINER;
 130         combiner_data->irq_mask = 0xff << ((combiner_nr % 4) << 3);
 131         combiner_data->parent_irq = irq;
 132
 133         /* Disable all interrupts */
 134         __raw_writel(combiner_data->irq_mask, base + COMBINER_ENABLE_CLEAR);
 135 }
 136
 137 static int combiner_irq_domain_xlate(struct irq_domain *d,
 138                                      struct device_node *controller,
 139                                      const u32 *intspec, unsigned int intsize,
 140                                      unsigned long *out_hwirq,
 141                                      unsigned int *out_type)
 142 {
 143         if (d->of_node != controller)
 144                 return -EINVAL;
 145
 146         if (intsize < 2)
 147                 return -EINVAL;
 148
 149         *out_hwirq = intspec[0] * IRQ_IN_COMBINER + intspec[1];
 150         *out_type = 0;
 151
 152         return 0;
 153 }
 154
 155 static int combiner_irq_domain_map(struct irq_domain *d, unsigned int irq,
 156                                    irq_hw_number_t hw)
 157 {
 158         struct combiner_chip_data *combiner_data = d->host_data;
 159
 160         irq_set_chip_and_handler(irq, &combiner_chip, handle_level_irq);
 161         irq_set_chip_data(irq, &combiner_data[hw >> 3]);
 162         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 163
 164         return 0;
 165 }
 166
 167 static struct irq_domain_ops combiner_irq_domain_ops = {
 168         .xlate  = combiner_irq_domain_xlate,
 169         .map    = combiner_irq_domain_map,
 170 };
 171
 172 static void __init combiner_init(void __iomem *combiner_base,
 173                                  struct device_node *np,
 174                                  unsigned int max_nr)
 175 {
 176         int i, irq;
 177         unsigned int nr_irq;
 178         struct combiner_chip_data *combiner_data;
 179
 180         nr_irq = max_nr * IRQ_IN_COMBINER;
 181
 182         combiner_data = kcalloc(max_nr, sizeof (*combiner_data), GFP_KERNEL);
 183         if (!combiner_data) {
 184                 pr_warning("%s: could not allocate combiner data\n", __func__);
 185                 return;
 186         }
 187
 188         combiner_irq_domain = irq_domain_add_linear(np, nr_irq,
 189                                 &combiner_irq_domain_ops, combiner_data);
 190         if (WARN_ON(!combiner_irq_domain)) {
 191                 pr_warning("%s: irq domain init failed\n", __func__);
 192                 return;
 193         }
 194
 195         for (i = 0; i < max_nr; i++) {
 196                 irq = irq_of_parse_and_map(np, i);
 197
 198                 combiner_init_one(&combiner_data[i], i,
 199                                   combiner_base + (i >> 2) * 0x10, irq);
 200                 combiner_cascade_irq(&combiner_data[i], irq);
 201         }
 202 }
 203
 204 static int __init combiner_of_init(struct device_node *np,
 205                                    struct device_node *parent)
 206 {
 207         void __iomem *combiner_base;
 208         unsigned int max_nr = 20;
 209
 210         combiner_base = of_iomap(np, 0);
 211         if (!combiner_base) {
 212                 pr_err("%s: failed to map combiner registers\n", __func__);
 213                 return -ENXIO;
 214         }
 215
 216         if (of_property_read_u32(np, "samsung,combiner-nr", &max_nr)) {
 217                 pr_info("%s: number of combiners not specified, "
 218                         "setting default as %d.\n",
 219                         __func__, max_nr);
 220         }
 221
 222         combiner_init(combiner_base, np, max_nr);
 223
 224         return 0;
 225 }
 226 IRQCHIP_DECLARE(exynos4210_combiner, "samsung,exynos4210-combiner",
 227                 combiner_of_init);