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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * arch/powerpc/platforms/embedded6xx/hlwd-pic.c
   4  *
   5  * Nintendo Wii "Hollywood" interrupt controller support.
   6  * Copyright (C) 2009 The GameCube Linux Team
   7  * Copyright (C) 2009 Albert Herranz
   8  */
   9 #define DRV_MODULE_NAME "hlwd-pic"
  10 #define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/irq.h>
  14 #include <linux/of.h>
  15 #include <linux/of_address.h>
  16 #include <linux/of_irq.h>
  17 #include <asm/io.h>
  18
  19 #include "hlwd-pic.h"
  20
  21 #define HLWD_NR_IRQS    32
  22
  23 /*
  24  * Each interrupt has a corresponding bit in both
  25  * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
  26  *
  27  * Enabling/disabling an interrupt line involves asserting/clearing
  28  * the corresponding bit in IMR. ACK'ing a request simply involves
  29  * asserting the corresponding bit in ICR.
  30  */
  31 #define HW_BROADWAY_ICR         0x00
  32 #define HW_BROADWAY_IMR         0x04
  33 #define HW_STARLET_ICR          0x08
  34 #define HW_STARLET_IMR          0x0c
  35
  36
  37 /*
  38  * IRQ chip hooks.
  39  *
  40  */
  41
  42 static void hlwd_pic_mask_and_ack(struct irq_data *d)
  43 {
  44         int irq = irqd_to_hwirq(d);
  45         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  46         u32 mask = 1 << irq;
  47
  48         clrbits32(io_base + HW_BROADWAY_IMR, mask);
  49         out_be32(io_base + HW_BROADWAY_ICR, mask);
  50 }
  51
  52 static void hlwd_pic_ack(struct irq_data *d)
  53 {
  54         int irq = irqd_to_hwirq(d);
  55         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  56
  57         out_be32(io_base + HW_BROADWAY_ICR, 1 << irq);
  58 }
  59
  60 static void hlwd_pic_mask(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         clrbits32(io_base + HW_BROADWAY_IMR, 1 << irq);
  66 }
  67
  68 static void hlwd_pic_unmask(struct irq_data *d)
  69 {
  70         int irq = irqd_to_hwirq(d);
  71         void __iomem *io_base = irq_data_get_irq_chip_data(d);
  72
  73         setbits32(io_base + HW_BROADWAY_IMR, 1 << irq);
  74
  75         /* Make sure the ARM (aka. Starlet) doesn't handle this interrupt. */
  76         clrbits32(io_base + HW_STARLET_IMR, 1 << irq);
  77 }
  78
  79
  80 static struct irq_chip hlwd_pic = {
  81         .name           = "hlwd-pic",
  82         .irq_ack        = hlwd_pic_ack,
  83         .irq_mask_ack   = hlwd_pic_mask_and_ack,
  84         .irq_mask       = hlwd_pic_mask,
  85         .irq_unmask     = hlwd_pic_unmask,
  86 };
  87
  88 /*
  89  * IRQ host hooks.
  90  *
  91  */
  92
  93 static struct irq_domain *hlwd_irq_host;
  94
  95 static int hlwd_pic_map(struct irq_domain *h, unsigned int virq,
  96                            irq_hw_number_t hwirq)
  97 {
  98         irq_set_chip_data(virq, h->host_data);
  99         irq_set_status_flags(virq, IRQ_LEVEL);
 100         irq_set_chip_and_handler(virq, &hlwd_pic, handle_level_irq);
 101         return 0;
 102 }
 103
 104 static const struct irq_domain_ops hlwd_irq_domain_ops = {
 105         .map = hlwd_pic_map,
 106 };
 107
 108 static unsigned int __hlwd_pic_get_irq(struct irq_domain *h)
 109 {
 110         void __iomem *io_base = h->host_data;
 111         int irq;
 112         u32 irq_status;
 113
 114         irq_status = in_be32(io_base + HW_BROADWAY_ICR) &
 115                      in_be32(io_base + HW_BROADWAY_IMR);
 116         if (irq_status == 0)
 117                 return 0;       /* no more IRQs pending */
 118
 119         irq = __ffs(irq_status);
 120         return irq_linear_revmap(h, irq);
 121 }
 122
 123 static void hlwd_pic_irq_cascade(struct irq_desc *desc)
 124 {
 125         struct irq_chip *chip = irq_desc_get_chip(desc);
 126         struct irq_domain *irq_domain = irq_desc_get_handler_data(desc);
 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_domain);
 134         if (virq)
 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 static struct irq_domain *hlwd_pic_init(struct device_node *np)
 159 {
 160         struct irq_domain *irq_domain;
 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_domain = irq_domain_add_linear(np, HLWD_NR_IRQS,
 181                                            &hlwd_irq_domain_ops, io_base);
 182         if (!irq_domain) {
 183                 pr_err("failed to allocate irq_domain\n");
 184                 iounmap(io_base);
 185                 return NULL;
 186         }
 187
 188         return irq_domain;
 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_domain *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