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

   1 /*
   2  * arch/powerpc/platforms/embedded6xx/hlwd-pic.c
   3  *
   4  * Nintendo Wii "Hollywood" interrupt controller support.
   5  * Copyright (C) 2009 The GameCube Linux Team
   6  * Copyright (C) 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 "hlwd-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 "hlwd-pic.h"
  24
  25 #define HLWD_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 asserting/clearing
  32  * the corresponding bit in IMR. ACK'ing a request simply involves
  33  * asserting the corresponding bit in ICR.
  34  */
  35 #define HW_BROADWAY_ICR         0x00
  36 #define HW_BROADWAY_IMR         0x04
  37
  38
  39 /*
  40  * IRQ chip hooks.
  41  *
  42  */
  43
  44 static void hlwd_pic_mask_and_ack(struct irq_data *d)
  45 {
  46         int irq = irqd_to_hwirq(d);
  47         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  48         u32 mask = 1 << irq;
  49
  50         clrbits32(io_base + HW_BROADWAY_IMR, mask);
  51         out_be32(io_base + HW_BROADWAY_ICR, mask);
  52 }
  53
  54 static void hlwd_pic_ack(struct irq_data *d)
  55 {
  56         int irq = irqd_to_hwirq(d);
  57         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  58
  59         out_be32(io_base + HW_BROADWAY_ICR, 1 << irq);
  60 }
  61
  62 static void hlwd_pic_mask(struct irq_data *d)
  63 {
  64         int irq = irqd_to_hwirq(d);
  65         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  66
  67         clrbits32(io_base + HW_BROADWAY_IMR, 1 << irq);
  68 }
  69
  70 static void hlwd_pic_unmask(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         setbits32(io_base + HW_BROADWAY_IMR, 1 << irq);
  76 }
  77
  78
  79 static struct irq_chip hlwd_pic = {
  80         .name           = "hlwd-pic",
  81         .irq_ack        = hlwd_pic_ack,
  82         .irq_mask_ack   = hlwd_pic_mask_and_ack,
  83         .irq_mask       = hlwd_pic_mask,
  84         .irq_unmask     = hlwd_pic_unmask,
  85 };
  86
  87 /*
  88  * IRQ host hooks.
  89  *
  90  */
  91
  92 static struct irq_host *hlwd_irq_host;
  93
  94 static int hlwd_pic_map(struct irq_host *h, unsigned int virq,
  95                            irq_hw_number_t hwirq)
  96 {
  97         irq_set_chip_data(virq, h->host_data);
  98         irq_set_status_flags(virq, IRQ_LEVEL);
  99         irq_set_chip_and_handler(virq, &hlwd_pic, handle_level_irq);
 100         return 0;
 101 }
 102
 103 static struct irq_host_ops hlwd_irq_host_ops = {
 104         .map = hlwd_pic_map,
 105 };
 106
 107 static unsigned int __hlwd_pic_get_irq(struct irq_host *h)
 108 {
 109         void __iomem *io_base = h->host_data;
 110         int irq;
 111         u32 irq_status;
 112
 113         irq_status = in_be32(io_base + HW_BROADWAY_ICR) &
 114                      in_be32(io_base + HW_BROADWAY_IMR);
 115         if (irq_status == 0)
 116                 return NO_IRQ;  /* no more IRQs pending */
 117
 118         irq = __ffs(irq_status);
 119         return irq_linear_revmap(h, irq);
 120 }
 121
 122 static void hlwd_pic_irq_cascade(unsigned int cascade_virq,
 123                                       struct irq_desc *desc)
 124 {
 125         struct irq_chip *chip = irq_desc_get_chip(desc);
 126         struct irq_host *irq_host = irq_get_handler_data(cascade_virq);
 127         unsigned int virq;
 128
 129         raw_spin_lock(&desc->lock);
 130         chip->irq_mask(&desc->irq_data); /* IRQ_LEVEL */
 131         raw_spin_unlock(&desc->lock);
 132
 133         virq = __hlwd_pic_get_irq(irq_host);
 134         if (virq != NO_IRQ)
 135                 generic_handle_irq(virq);
 136         else
 137                 pr_err("spurious interrupt!\n");
 138
 139         raw_spin_lock(&desc->lock);
 140         chip->irq_ack(&desc->irq_data); /* IRQ_LEVEL */
 141         if (!irqd_irq_disabled(&desc->irq_data) && chip->irq_unmask)
 142                 chip->irq_unmask(&desc->irq_data);
 143         raw_spin_unlock(&desc->lock);
 144 }
 145
 146 /*
 147  * Platform hooks.
 148  *
 149  */
 150
 151 static void __hlwd_quiesce(void __iomem *io_base)
 152 {
 153         /* mask and ack all IRQs */
 154         out_be32(io_base + HW_BROADWAY_IMR, 0);
 155         out_be32(io_base + HW_BROADWAY_ICR, 0xffffffff);
 156 }
 157
 158 struct irq_host *hlwd_pic_init(struct device_node *np)
 159 {
 160         struct irq_host *irq_host;
 161         struct resource res;
 162         void __iomem *io_base;
 163         int retval;
 164
 165         retval = of_address_to_resource(np, 0, &res);
 166         if (retval) {
 167                 pr_err("no io memory range found\n");
 168                 return NULL;
 169         }
 170         io_base = ioremap(res.start, resource_size(&res));
 171         if (!io_base) {
 172                 pr_err("ioremap failed\n");
 173                 return NULL;
 174         }
 175
 176         pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
 177
 178         __hlwd_quiesce(io_base);
 179
 180         irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, HLWD_NR_IRQS,
 181                                   &hlwd_irq_host_ops, -1);
 182         if (!irq_host) {
 183                 pr_err("failed to allocate irq_host\n");
 184                 return NULL;
 185         }
 186         irq_host->host_data = io_base;
 187
 188         return irq_host;
 189 }
 190
 191 unsigned int hlwd_pic_get_irq(void)
 192 {
 193         return __hlwd_pic_get_irq(hlwd_irq_host);
 194 }
 195
 196 /*
 197  * Probe function.
 198  *
 199  */
 200
 201 void hlwd_pic_probe(void)
 202 {
 203         struct irq_host *host;
 204         struct device_node *np;
 205         const u32 *interrupts;
 206         int cascade_virq;
 207
 208         for_each_compatible_node(np, NULL, "nintendo,hollywood-pic") {
 209                 interrupts = of_get_property(np, "interrupts", NULL);
 210                 if (interrupts) {
 211                         host = hlwd_pic_init(np);
 212                         BUG_ON(!host);
 213                         cascade_virq = irq_of_parse_and_map(np, 0);
 214                         irq_set_handler_data(cascade_virq, host);
 215                         irq_set_chained_handler(cascade_virq,
 216                                                 hlwd_pic_irq_cascade);
 217                         hlwd_irq_host = host;
 218                         break;
 219                 }
 220         }
 221 }
 222
 223 /**
 224  * hlwd_quiesce() - quiesce hollywood irq controller
 225  *
 226  * Mask and ack all interrupt sources.
 227  *
 228  */
 229 void hlwd_quiesce(void)
 230 {
 231         void __iomem *io_base = hlwd_irq_host->host_data;
 232
 233         __hlwd_quiesce(io_base);
 234 }
 235