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 <linux/of_address.h>
  22 #include <asm/io.h>
  23
  24 #include "flipper-pic.h"
  25
  26 #define FLIPPER_NR_IRQS         32
  27
  28 /*
  29  * Each interrupt has a corresponding bit in both
  30  * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
  31  *
  32  * Enabling/disabling an interrupt line involves setting/clearing
  33  * the corresponding bit in IMR.
  34  * Except for the RSW interrupt, all interrupts get deasserted automatically
  35  * when the source deasserts the interrupt.
  36  */
  37 #define FLIPPER_ICR             0x00
  38 #define FLIPPER_ICR_RSS         (1<<16) /* reset switch state */
  39
  40 #define FLIPPER_IMR             0x04
  41
  42 #define FLIPPER_RESET           0x24
  43
  44
  45 /*
  46  * IRQ chip hooks.
  47  *
  48  */
  49
  50 static void flipper_pic_mask_and_ack(struct irq_data *d)
  51 {
  52         int irq = irqd_to_hwirq(d);
  53         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  54         u32 mask = 1 << irq;
  55
  56         clrbits32(io_base + FLIPPER_IMR, mask);
  57         /* this is at least needed for RSW */
  58         out_be32(io_base + FLIPPER_ICR, mask);
  59 }
  60
  61 static void flipper_pic_ack(struct irq_data *d)
  62 {
  63         int irq = irqd_to_hwirq(d);
  64         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  65
  66         /* this is at least needed for RSW */
  67         out_be32(io_base + FLIPPER_ICR, 1 << irq);
  68 }
  69
  70 static void flipper_pic_mask(struct irq_data *d)
  71 {
  72         int irq = irqd_to_hwirq(d);
  73         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  74
  75         clrbits32(io_base + FLIPPER_IMR, 1 << irq);
  76 }
  77
  78 static void flipper_pic_unmask(struct irq_data *d)
  79 {
  80         int irq = irqd_to_hwirq(d);
  81         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  82
  83         setbits32(io_base + FLIPPER_IMR, 1 << irq);
  84 }
  85
  86
  87 static struct irq_chip flipper_pic = {
  88         .name           = "flipper-pic",
  89         .irq_ack        = flipper_pic_ack,
  90         .irq_mask_ack   = flipper_pic_mask_and_ack,
  91         .irq_mask       = flipper_pic_mask,
  92         .irq_unmask     = flipper_pic_unmask,
  93 };
  94
  95 /*
  96  * IRQ host hooks.
  97  *
  98  */
  99
 100 static struct irq_domain *flipper_irq_host;
 101
 102 static int flipper_pic_map(struct irq_domain *h, unsigned int virq,
 103                            irq_hw_number_t hwirq)
 104 {
 105         irq_set_chip_data(virq, h->host_data);
 106         irq_set_status_flags(virq, IRQ_LEVEL);
 107         irq_set_chip_and_handler(virq, &flipper_pic, handle_level_irq);
 108         return 0;
 109 }
 110
 111 static int flipper_pic_match(struct irq_domain *h, struct device_node *np,
 112                              enum irq_domain_bus_token bus_token)
 113 {
 114         return 1;
 115 }
 116
 117
 118 static const struct irq_domain_ops flipper_irq_domain_ops = {
 119         .map = flipper_pic_map,
 120         .match = flipper_pic_match,
 121 };
 122
 123 /*
 124  * Platform hooks.
 125  *
 126  */
 127
 128 static void __flipper_quiesce(void __iomem *io_base)
 129 {
 130         /* mask and ack all IRQs */
 131         out_be32(io_base + FLIPPER_IMR, 0x00000000);
 132         out_be32(io_base + FLIPPER_ICR, 0xffffffff);
 133 }
 134
 135 struct irq_domain * __init flipper_pic_init(struct device_node *np)
 136 {
 137         struct device_node *pi;
 138         struct irq_domain *irq_domain = NULL;
 139         struct resource res;
 140         void __iomem *io_base;
 141         int retval;
 142
 143         pi = of_get_parent(np);
 144         if (!pi) {
 145                 pr_err("no parent found\n");
 146                 goto out;
 147         }
 148         if (!of_device_is_compatible(pi, "nintendo,flipper-pi")) {
 149                 pr_err("unexpected parent compatible\n");
 150                 goto out;
 151         }
 152
 153         retval = of_address_to_resource(pi, 0, &res);
 154         if (retval) {
 155                 pr_err("no io memory range found\n");
 156                 goto out;
 157         }
 158         io_base = ioremap(res.start, resource_size(&res));
 159
 160         pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
 161
 162         __flipper_quiesce(io_base);
 163
 164         irq_domain = irq_domain_add_linear(np, FLIPPER_NR_IRQS,
 165                                   &flipper_irq_domain_ops, io_base);
 166         if (!irq_domain) {
 167                 pr_err("failed to allocate irq_domain\n");
 168                 return NULL;
 169         }
 170
 171 out:
 172         return irq_domain;
 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