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(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
  60 static 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
  69 static 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
  77 static 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
  86 static 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
  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         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
 110 static int flipper_pic_match(struct irq_host *h, struct device_node *np)
 111 {
 112         return 1;
 113 }
 114
 115
 116 static 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
 126 static 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
 133 struct 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
 171 out:
 172         return irq_host;
 173 }
 174
 175 unsigned 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
 195 void __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  */
 221 void 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  */
 231 void 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  */
 244 int 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