arch/powerpc/platforms/embedded6xx/flipper-pic.c

   1 /*
   2  * arch/powerpc/platforms/embedded6xx/flipper-pic.c
   3  *
   4  * Nintendo GameCube/Wii "Flipper" interrupt controller support.
   5  * Copyright (C) 2004-2009 The GameCube Linux Team
   6  * Copyright (C) 2007,2008,2009 Albert Herranz
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  */
  14 #define DRV_MODULE_NAME "flipper-pic"
  15 #define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
  16
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/irq.h>
  20 #include <linux/of.h>
  21 #include <asm/io.h>
  22
  23 #include "flipper-pic.h"
  24
  25 #define FLIPPER_NR_IRQS         32
  26
  27 /*
  28  * Each interrupt has a corresponding bit in both
  29  * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
  30  *
  31  * Enabling/disabling an interrupt line involves setting/clearing
  32  * the corresponding bit in IMR.
  33  * Except for the RSW interrupt, all interrupts get deasserted automatically
  34  * when the source deasserts the interrupt.
  35  */
  36 #define FLIPPER_ICR             0x00
  37 #define FLIPPER_ICR_RSS         (1<<16) /* reset switch state */
  38
  39 #define FLIPPER_IMR             0x04
  40
  41 #define FLIPPER_RESET           0x24
  42
  43
  44 /*
  45  * IRQ chip hooks.
  46  *
  47  */
  48
  49 static void flipper_pic_mask_and_ack(unsigned int virq)
  50 {
  51         int irq = virq_to_hw(virq);
  52         void __iomem *io_base = get_irq_chip_data(virq);
  53         u32 mask = 1 << irq;
  54
  55         clrbits32(io_base + FLIPPER_IMR, mask);
  56         /* this is at least needed for RSW */
  57         out_be32(io_base + FLIPPER_ICR, mask);
  58 }
  59
  60 static void flipper_pic_ack(unsigned int virq)
  61 {
  62         int irq = virq_to_hw(virq);
  63         void __iomem *io_base = get_irq_chip_data(virq);
  64
  65         /* this is at least needed for RSW */
  66         out_be32(io_base + FLIPPER_ICR, 1 << irq);
  67 }
  68
  69 static void flipper_pic_mask(unsigned int virq)
  70 {
  71         int irq = virq_to_hw(virq);
  72         void __iomem *io_base = get_irq_chip_data(virq);
  73
  74         clrbits32(io_base + FLIPPER_IMR, 1 << irq);
  75 }
  76
  77 static void flipper_pic_unmask(unsigned int virq)
  78 {
  79         int irq = virq_to_hw(virq);
  80         void __iomem *io_base = get_irq_chip_data(virq);
  81
  82         setbits32(io_base + FLIPPER_IMR, 1 << irq);
  83 }
  84
  85
  86 static struct irq_chip flipper_pic = {
  87         .name           = "flipper-pic",
  88         .ack            = flipper_pic_ack,
  89         .mask_ack       = flipper_pic_mask_and_ack,
  90         .mask           = flipper_pic_mask,
  91         .unmask         = flipper_pic_unmask,
  92 };
  93
  94 /*
  95  * IRQ host hooks.
  96  *
  97  */
  98
  99 static struct irq_host *flipper_irq_host;
 100
 101 static int flipper_pic_map(struct irq_host *h, unsigned int virq,
 102                            irq_hw_number_t hwirq)
 103 {
 104         set_irq_chip_data(virq, h->host_data);
 105         irq_to_desc(virq)->status |= IRQ_LEVEL;
 106         set_irq_chip_and_handler(virq, &flipper_pic, handle_level_irq);
 107         return 0;
 108 }
 109
 110 static void flipper_pic_unmap(struct irq_host *h, unsigned int irq)
 111 {
 112         set_irq_chip_data(irq, NULL);
 113         set_irq_chip(irq, NULL);
 114 }
 115
 116 static int flipper_pic_match(struct irq_host *h, struct device_node *np)
 117 {
 118         return 1;
 119 }
 120
 121
 122 static struct irq_host_ops flipper_irq_host_ops = {
 123         .map = flipper_pic_map,
 124         .unmap = flipper_pic_unmap,
 125         .match = flipper_pic_match,
 126 };
 127
 128 /*
 129  * Platform hooks.
 130  *
 131  */
 132
 133 static void __flipper_quiesce(void __iomem *io_base)
 134 {
 135         /* mask and ack all IRQs */
 136         out_be32(io_base + FLIPPER_IMR, 0x00000000);
 137         out_be32(io_base + FLIPPER_ICR, 0xffffffff);
 138 }
 139
 140 struct irq_host * __init flipper_pic_init(struct device_node *np)
 141 {
 142         struct device_node *pi;
 143         struct irq_host *irq_host = NULL;
 144         struct resource res;
 145         void __iomem *io_base;
 146         int retval;
 147
 148         pi = of_get_parent(np);
 149         if (!pi) {
 150                 pr_err("no parent found\n");
 151                 goto out;
 152         }
 153         if (!of_device_is_compatible(pi, "nintendo,flipper-pi")) {
 154                 pr_err("unexpected parent compatible\n");
 155                 goto out;
 156         }
 157
 158         retval = of_address_to_resource(pi, 0, &res);
 159         if (retval) {
 160                 pr_err("no io memory range found\n");
 161                 goto out;
 162         }
 163         io_base = ioremap(res.start, resource_size(&res));
 164
 165         pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
 166
 167         __flipper_quiesce(io_base);
 168
 169         irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, FLIPPER_NR_IRQS,
 170                                   &flipper_irq_host_ops, -1);
 171         if (!irq_host) {
 172                 pr_err("failed to allocate irq_host\n");
 173                 return NULL;
 174         }
 175
 176         irq_host->host_data = io_base;
 177
 178 out:
 179         return irq_host;
 180 }
 181
 182 unsigned int flipper_pic_get_irq(void)
 183 {
 184         void __iomem *io_base = flipper_irq_host->host_data;
 185         int irq;
 186         u32 irq_status;
 187
 188         irq_status = in_be32(io_base + FLIPPER_ICR) &
 189                      in_be32(io_base + FLIPPER_IMR);
 190         if (irq_status == 0)
 191                 return NO_IRQ;  /* no more IRQs pending */
 192
 193         irq = __ffs(irq_status);
 194         return irq_linear_revmap(flipper_irq_host, irq);
 195 }
 196
 197 /*
 198  * Probe function.
 199  *
 200  */
 201
 202 void __init flipper_pic_probe(void)
 203 {
 204         struct device_node *np;
 205
 206         np = of_find_compatible_node(NULL, NULL, "nintendo,flipper-pic");
 207         BUG_ON(!np);
 208
 209         flipper_irq_host = flipper_pic_init(np);
 210         BUG_ON(!flipper_irq_host);
 211
 212         irq_set_default_host(flipper_irq_host);
 213
 214         of_node_put(np);
 215 }
 216
 217 /*
 218  * Misc functions related to the flipper chipset.
 219  *
 220  */
 221
 222 /**
 223  * flipper_quiesce() - quiesce flipper irq controller
 224  *
 225  * Mask and ack all interrupt sources.
 226  *
 227  */
 228 void flipper_quiesce(void)
 229 {
 230         void __iomem *io_base = flipper_irq_host->host_data;
 231
 232         __flipper_quiesce(io_base);
 233 }
 234
 235 /*
 236  * Resets the platform.
 237  */
 238 void flipper_platform_reset(void)
 239 {
 240         void __iomem *io_base;
 241
 242         if (flipper_irq_host && flipper_irq_host->host_data) {
 243                 io_base = flipper_irq_host->host_data;
 244                 out_8(io_base + FLIPPER_RESET, 0x00);
 245         }
 246 }
 247
 248 /*
 249  * Returns non-zero if the reset button is pressed.
 250  */
 251 int flipper_is_reset_button_pressed(void)
 252 {
 253         void __iomem *io_base;
 254         u32 icr;
 255
 256         if (flipper_irq_host && flipper_irq_host->host_data) {
 257                 io_base = flipper_irq_host->host_data;
 258                 icr = in_be32(io_base + FLIPPER_ICR);
 259                 return !(icr & FLIPPER_ICR_RSS);
 260         }
 261         return 0;
 262 }
 263