linux/arch/powerpc/platforms/embedded6xx/flipper-pic.c
<<
>>
Prefs
   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
  49static void flipper_pic_mask_and_ack(struct irq_data *d)
  50{
  51        int irq = irqd_to_hwirq(d);
  52        void __iomem *io_base = irq_data_get_irq_chip_data(d);
  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
  60static void flipper_pic_ack(struct irq_data *d)
  61{
  62        int irq = irqd_to_hwirq(d);
  63        void __iomem *io_base = irq_data_get_irq_chip_data(d);
  64
  65        /* this is at least needed for RSW */
  66        out_be32(io_base + FLIPPER_ICR, 1 << irq);
  67}
  68
  69static void flipper_pic_mask(struct irq_data *d)
  70{
  71        int irq = irqd_to_hwirq(d);
  72        void __iomem *io_base = irq_data_get_irq_chip_data(d);
  73
  74        clrbits32(io_base + FLIPPER_IMR, 1 << irq);
  75}
  76
  77static void flipper_pic_unmask(struct irq_data *d)
  78{
  79        int irq = irqd_to_hwirq(d);
  80        void __iomem *io_base = irq_data_get_irq_chip_data(d);
  81
  82        setbits32(io_base + FLIPPER_IMR, 1 << irq);
  83}
  84
  85
  86static struct irq_chip flipper_pic = {
  87        .name           = "flipper-pic",
  88        .irq_ack        = flipper_pic_ack,
  89        .irq_mask_ack   = flipper_pic_mask_and_ack,
  90        .irq_mask       = flipper_pic_mask,
  91        .irq_unmask     = flipper_pic_unmask,
  92};
  93
  94/*
  95 * IRQ host hooks.
  96 *
  97 */
  98
  99static struct irq_host *flipper_irq_host;
 100
 101static int flipper_pic_map(struct irq_host *h, unsigned int virq,
 102                           irq_hw_number_t hwirq)
 103{
 104        irq_set_chip_data(virq, h->host_data);
 105        irq_set_status_flags(virq, IRQ_LEVEL);
 106        irq_set_chip_and_handler(virq, &flipper_pic, handle_level_irq);
 107        return 0;
 108}
 109
 110static int flipper_pic_match(struct irq_host *h, struct device_node *np)
 111{
 112        return 1;
 113}
 114
 115
 116static struct irq_host_ops flipper_irq_host_ops = {
 117        .map = flipper_pic_map,
 118        .match = flipper_pic_match,
 119};
 120
 121/*
 122 * Platform hooks.
 123 *
 124 */
 125
 126static void __flipper_quiesce(void __iomem *io_base)
 127{
 128        /* mask and ack all IRQs */
 129        out_be32(io_base + FLIPPER_IMR, 0x00000000);
 130        out_be32(io_base + FLIPPER_ICR, 0xffffffff);
 131}
 132
 133struct irq_host * __init flipper_pic_init(struct device_node *np)
 134{
 135        struct device_node *pi;
 136        struct irq_host *irq_host = NULL;
 137        struct resource res;
 138        void __iomem *io_base;
 139        int retval;
 140
 141        pi = of_get_parent(np);
 142        if (!pi) {
 143                pr_err("no parent found\n");
 144                goto out;
 145        }
 146        if (!of_device_is_compatible(pi, "nintendo,flipper-pi")) {
 147                pr_err("unexpected parent compatible\n");
 148                goto out;
 149        }
 150
 151        retval = of_address_to_resource(pi, 0, &res);
 152        if (retval) {
 153                pr_err("no io memory range found\n");
 154                goto out;
 155        }
 156        io_base = ioremap(res.start, resource_size(&res));
 157
 158        pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
 159
 160        __flipper_quiesce(io_base);
 161
 162        irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, FLIPPER_NR_IRQS,
 163                                  &flipper_irq_host_ops, -1);
 164        if (!irq_host) {
 165                pr_err("failed to allocate irq_host\n");
 166                return NULL;
 167        }
 168
 169        irq_host->host_data = io_base;
 170
 171out:
 172        return irq_host;
 173}
 174
 175unsigned int flipper_pic_get_irq(void)
 176{
 177        void __iomem *io_base = flipper_irq_host->host_data;
 178        int irq;
 179        u32 irq_status;
 180
 181        irq_status = in_be32(io_base + FLIPPER_ICR) &
 182                     in_be32(io_base + FLIPPER_IMR);
 183        if (irq_status == 0)
 184                return NO_IRQ;  /* no more IRQs pending */
 185
 186        irq = __ffs(irq_status);
 187        return irq_linear_revmap(flipper_irq_host, irq);
 188}
 189
 190/*
 191 * Probe function.
 192 *
 193 */
 194
 195void __init flipper_pic_probe(void)
 196{
 197        struct device_node *np;
 198
 199        np = of_find_compatible_node(NULL, NULL, "nintendo,flipper-pic");
 200        BUG_ON(!np);
 201
 202        flipper_irq_host = flipper_pic_init(np);
 203        BUG_ON(!flipper_irq_host);
 204
 205        irq_set_default_host(flipper_irq_host);
 206
 207        of_node_put(np);
 208}
 209
 210/*
 211 * Misc functions related to the flipper chipset.
 212 *
 213 */
 214
 215/**
 216 * flipper_quiesce() - quiesce flipper irq controller
 217 *
 218 * Mask and ack all interrupt sources.
 219 *
 220 */
 221void flipper_quiesce(void)
 222{
 223        void __iomem *io_base = flipper_irq_host->host_data;
 224
 225        __flipper_quiesce(io_base);
 226}
 227
 228/*
 229 * Resets the platform.
 230 */
 231void flipper_platform_reset(void)
 232{
 233        void __iomem *io_base;
 234
 235        if (flipper_irq_host && flipper_irq_host->host_data) {
 236                io_base = flipper_irq_host->host_data;
 237                out_8(io_base + FLIPPER_RESET, 0x00);
 238        }
 239}
 240
 241/*
 242 * Returns non-zero if the reset button is pressed.
 243 */
 244int flipper_is_reset_button_pressed(void)
 245{
 246        void __iomem *io_base;
 247        u32 icr;
 248
 249        if (flipper_irq_host && flipper_irq_host->host_data) {
 250                io_base = flipper_irq_host->host_data;
 251                icr = in_be32(io_base + FLIPPER_ICR);
 252                return !(icr & FLIPPER_ICR_RSS);
 253        }
 254        return 0;
 255}
 256
 257