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/irqdomain.h>
  16 #include <linux/irqchip/chained_irq.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_irq.h>
  19 #include <asm/mach/irq.h>
  20
  21 #include <plat/cpu.h>
  22
  23 #include "irqchip.h"
  24
  25 #define COMBINER_ENABLE_SET     0x0
  26 #define COMBINER_ENABLE_CLEAR   0x4
  27 #define COMBINER_INT_STATUS     0xC
  28
  29 static DEFINE_SPINLOCK(irq_controller_lock);
  30
  31 struct combiner_chip_data {
  32         unsigned int irq_offset;
  33         unsigned int irq_mask;
  34         void __iomem *base;
  35 };
  36
  37 static struct irq_domain *combiner_irq_domain;
  38 static struct combiner_chip_data combiner_data[MAX_COMBINER_NR];
  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 = __ffs(status);
  80
  81         cascade_irq = combiner_irq + (chip_data->irq_offset & ~31);
  82         if (unlikely(cascade_irq >= NR_IRQS))
  83                 do_bad_IRQ(cascade_irq, desc);
  84         else
  85                 generic_handle_irq(cascade_irq);
  86
  87  out:
  88         chained_irq_exit(chip, desc);
  89 }
  90
  91 static struct irq_chip combiner_chip = {
  92         .name           = "COMBINER",
  93         .irq_mask       = combiner_mask_irq,
  94         .irq_unmask     = combiner_unmask_irq,
  95 };
  96
  97 static void __init combiner_cascade_irq(unsigned int combiner_nr, unsigned int irq)
  98 {
  99         unsigned int max_nr;
 100
 101         if (soc_is_exynos5250())
 102                 max_nr = EXYNOS5_MAX_COMBINER_NR;
 103         else
 104                 max_nr = EXYNOS4_MAX_COMBINER_NR;
 105
 106         if (combiner_nr >= max_nr)
 107                 BUG();
 108         if (irq_set_handler_data(irq, &combiner_data[combiner_nr]) != 0)
 109                 BUG();
 110         irq_set_chained_handler(irq, combiner_handle_cascade_irq);
 111 }
 112
 113 static void __init combiner_init_one(unsigned int combiner_nr,
 114                                      void __iomem *base)
 115 {
 116         combiner_data[combiner_nr].base = base;
 117         combiner_data[combiner_nr].irq_offset = irq_find_mapping(
 118                 combiner_irq_domain, combiner_nr * MAX_IRQ_IN_COMBINER);
 119         combiner_data[combiner_nr].irq_mask = 0xff << ((combiner_nr % 4) << 3);
 120
 121         /* Disable all interrupts */
 122         __raw_writel(combiner_data[combiner_nr].irq_mask,
 123                      base + COMBINER_ENABLE_CLEAR);
 124 }
 125
 126 #ifdef CONFIG_OF
 127 static int combiner_irq_domain_xlate(struct irq_domain *d,
 128                                      struct device_node *controller,
 129                                      const u32 *intspec, unsigned int intsize,
 130                                      unsigned long *out_hwirq,
 131                                      unsigned int *out_type)
 132 {
 133         if (d->of_node != controller)
 134                 return -EINVAL;
 135
 136         if (intsize < 2)
 137                 return -EINVAL;
 138
 139         *out_hwirq = intspec[0] * MAX_IRQ_IN_COMBINER + intspec[1];
 140         *out_type = 0;
 141
 142         return 0;
 143 }
 144 #else
 145 static int combiner_irq_domain_xlate(struct irq_domain *d,
 146                                      struct device_node *controller,
 147                                      const u32 *intspec, unsigned int intsize,
 148                                      unsigned long *out_hwirq,
 149                                      unsigned int *out_type)
 150 {
 151         return -EINVAL;
 152 }
 153 #endif
 154
 155 static int combiner_irq_domain_map(struct irq_domain *d, unsigned int irq,
 156                                    irq_hw_number_t hw)
 157 {
 158         irq_set_chip_and_handler(irq, &combiner_chip, handle_level_irq);
 159         irq_set_chip_data(irq, &combiner_data[hw >> 3]);
 160         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 161
 162         return 0;
 163 }
 164
 165 static struct irq_domain_ops combiner_irq_domain_ops = {
 166         .xlate  = combiner_irq_domain_xlate,
 167         .map    = combiner_irq_domain_map,
 168 };
 169
 170 void __init combiner_init(void __iomem *combiner_base,
 171                           struct device_node *np)
 172 {
 173         int i, irq, irq_base;
 174         unsigned int max_nr, nr_irq;
 175
 176         if (np) {
 177                 if (of_property_read_u32(np, "samsung,combiner-nr", &max_nr)) {
 178                         pr_warning("%s: number of combiners not specified, "
 179                                 "setting default as %d.\n",
 180                                 __func__, EXYNOS4_MAX_COMBINER_NR);
 181                         max_nr = EXYNOS4_MAX_COMBINER_NR;
 182                 }
 183         } else {
 184                 max_nr = soc_is_exynos5250() ? EXYNOS5_MAX_COMBINER_NR :
 185                                                 EXYNOS4_MAX_COMBINER_NR;
 186         }
 187         nr_irq = max_nr * MAX_IRQ_IN_COMBINER;
 188
 189         irq_base = irq_alloc_descs(COMBINER_IRQ(0, 0), 1, nr_irq, 0);
 190         if (IS_ERR_VALUE(irq_base)) {
 191                 irq_base = COMBINER_IRQ(0, 0);
 192                 pr_warning("%s: irq desc alloc failed. Continuing with %d as linux irq base\n", __func__, irq_base);
 193         }
 194
 195         combiner_irq_domain = irq_domain_add_legacy(np, nr_irq, irq_base, 0,
 196                                 &combiner_irq_domain_ops, &combiner_data);
 197         if (WARN_ON(!combiner_irq_domain)) {
 198                 pr_warning("%s: irq domain init failed\n", __func__);
 199                 return;
 200         }
 201
 202         for (i = 0; i < max_nr; i++) {
 203                 combiner_init_one(i, combiner_base + (i >> 2) * 0x10);
 204                 irq = IRQ_SPI(i);
 205 #ifdef CONFIG_OF
 206                 if (np)
 207                         irq = irq_of_parse_and_map(np, i);
 208 #endif
 209                 combiner_cascade_irq(i, irq);
 210         }
 211 }
 212
 213 #ifdef CONFIG_OF
 214 static int __init combiner_of_init(struct device_node *np,
 215                                    struct device_node *parent)
 216 {
 217         void __iomem *combiner_base;
 218
 219         combiner_base = of_iomap(np, 0);
 220         if (!combiner_base) {
 221                 pr_err("%s: failed to map combiner registers\n", __func__);
 222                 return -ENXIO;
 223         }
 224
 225         combiner_init(combiner_base, np);
 226
 227         return 0;
 228 }
 229 IRQCHIP_DECLARE(exynos4210_combiner, "samsung,exynos4210-combiner",
 230                 combiner_of_init);
 231 #endif