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
  21 #include "irqchip.h"
  22
  23 #define COMBINER_ENABLE_SET     0x0
  24 #define COMBINER_ENABLE_CLEAR   0x4
  25 #define COMBINER_INT_STATUS     0xC
  26
  27 #define IRQ_IN_COMBINER         8
  28
  29 static DEFINE_SPINLOCK(irq_controller_lock);
  30
  31 struct combiner_chip_data {
  32         unsigned int hwirq_offset;
  33         unsigned int irq_mask;
  34         void __iomem *base;
  35         unsigned int parent_irq;
  36 };
  37
  38 static struct irq_domain *combiner_irq_domain;
  39
  40 static inline void __iomem *combiner_base(struct irq_data *data)
  41 {
  42         struct combiner_chip_data *combiner_data =
  43                 irq_data_get_irq_chip_data(data);
  44
  45         return combiner_data->base;
  46 }
  47
  48 static void combiner_mask_irq(struct irq_data *data)
  49 {
  50         u32 mask = 1 << (data->hwirq % 32);
  51
  52         __raw_writel(mask, combiner_base(data) + COMBINER_ENABLE_CLEAR);
  53 }
  54
  55 static void combiner_unmask_irq(struct irq_data *data)
  56 {
  57         u32 mask = 1 << (data->hwirq % 32);
  58
  59         __raw_writel(mask, combiner_base(data) + COMBINER_ENABLE_SET);
  60 }
  61
  62 static void combiner_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
  63 {
  64         struct combiner_chip_data *chip_data = irq_get_handler_data(irq);
  65         struct irq_chip *chip = irq_get_chip(irq);
  66         unsigned int cascade_irq, combiner_irq;
  67         unsigned long status;
  68
  69         chained_irq_enter(chip, desc);
  70
  71         spin_lock(&irq_controller_lock);
  72         status = __raw_readl(chip_data->base + COMBINER_INT_STATUS);
  73         spin_unlock(&irq_controller_lock);
  74         status &= chip_data->irq_mask;
  75
  76         if (status == 0)
  77                 goto out;
  78
  79         combiner_irq = chip_data->hwirq_offset + __ffs(status);
  80         cascade_irq = irq_find_mapping(combiner_irq_domain, combiner_irq);
  81
  82         if (unlikely(!cascade_irq))
  83                 handle_bad_irq(irq, desc);
  84         else
  85                 generic_handle_irq(cascade_irq);
  86
  87  out:
  88         chained_irq_exit(chip, desc);
  89 }
  90
  91 #ifdef CONFIG_SMP
  92 static int combiner_set_affinity(struct irq_data *d,
  93                                  const struct cpumask *mask_val, bool force)
  94 {
  95         struct combiner_chip_data *chip_data = irq_data_get_irq_chip_data(d);
  96         struct irq_chip *chip = irq_get_chip(chip_data->parent_irq);
  97         struct irq_data *data = irq_get_irq_data(chip_data->parent_irq);
  98
  99         if (chip && chip->irq_set_affinity)
 100                 return chip->irq_set_affinity(data, mask_val, force);
 101         else
 102                 return -EINVAL;
 103 }
 104 #endif
 105
 106 static struct irq_chip combiner_chip = {
 107         .name                   = "COMBINER",
 108         .irq_mask               = combiner_mask_irq,
 109         .irq_unmask             = combiner_unmask_irq,
 110 #ifdef CONFIG_SMP
 111         .irq_set_affinity       = combiner_set_affinity,
 112 #endif
 113 };
 114
 115 static void __init combiner_cascade_irq(struct combiner_chip_data *combiner_data,
 116                                         unsigned int irq)
 117 {
 118         if (irq_set_handler_data(irq, combiner_data) != 0)
 119                 BUG();
 120         irq_set_chained_handler(irq, combiner_handle_cascade_irq);
 121 }
 122
 123 static void __init combiner_init_one(struct combiner_chip_data *combiner_data,
 124                                      unsigned int combiner_nr,
 125                                      void __iomem *base, unsigned int irq)
 126 {
 127         combiner_data->base = base;
 128         combiner_data->hwirq_offset = (combiner_nr & ~3) * IRQ_IN_COMBINER;
 129         combiner_data->irq_mask = 0xff << ((combiner_nr % 4) << 3);
 130         combiner_data->parent_irq = irq;
 131
 132         /* Disable all interrupts */
 133         __raw_writel(combiner_data->irq_mask, base + COMBINER_ENABLE_CLEAR);
 134 }
 135
 136 static int combiner_irq_domain_xlate(struct irq_domain *d,
 137                                      struct device_node *controller,
 138                                      const u32 *intspec, unsigned int intsize,
 139                                      unsigned long *out_hwirq,
 140                                      unsigned int *out_type)
 141 {
 142         if (d->of_node != controller)
 143                 return -EINVAL;
 144
 145         if (intsize < 2)
 146                 return -EINVAL;
 147
 148         *out_hwirq = intspec[0] * IRQ_IN_COMBINER + intspec[1];
 149         *out_type = 0;
 150
 151         return 0;
 152 }
 153
 154 static int combiner_irq_domain_map(struct irq_domain *d, unsigned int irq,
 155                                    irq_hw_number_t hw)
 156 {
 157         struct combiner_chip_data *combiner_data = d->host_data;
 158
 159         irq_set_chip_and_handler(irq, &combiner_chip, handle_level_irq);
 160         irq_set_chip_data(irq, &combiner_data[hw >> 3]);
 161         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 162
 163         return 0;
 164 }
 165
 166 static struct irq_domain_ops combiner_irq_domain_ops = {
 167         .xlate  = combiner_irq_domain_xlate,
 168         .map    = combiner_irq_domain_map,
 169 };
 170
 171 static void __init combiner_init(void __iomem *combiner_base,
 172                                  struct device_node *np,
 173                                  unsigned int max_nr)
 174 {
 175         int i, irq;
 176         unsigned int nr_irq;
 177         struct combiner_chip_data *combiner_data;
 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_warning("%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_warning("%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 static int __init combiner_of_init(struct device_node *np,
 204                                    struct device_node *parent)
 205 {
 206         void __iomem *combiner_base;
 207         unsigned int max_nr = 20;
 208
 209         combiner_base = of_iomap(np, 0);
 210         if (!combiner_base) {
 211                 pr_err("%s: failed to map combiner registers\n", __func__);
 212                 return -ENXIO;
 213         }
 214
 215         if (of_property_read_u32(np, "samsung,combiner-nr", &max_nr)) {
 216                 pr_info("%s: number of combiners not specified, "
 217                         "setting default as %d.\n",
 218                         __func__, max_nr);
 219         }
 220
 221         combiner_init(combiner_base, np, max_nr);
 222
 223         return 0;
 224 }
 225 IRQCHIP_DECLARE(exynos4210_combiner, "samsung,exynos4210-combiner",
 226                 combiner_of_init);