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/irq.h> 19 #include <linux/of.h> 20 #include <linux/of_address.h> 21 #include <linux/of_irq.h> 22 #include <asm/io.h> 23 24 #include "hlwd-pic.h" 25 26 #define HLWD_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 asserting/clearing 33 * the corresponding bit in IMR. ACK'ing a request simply involves 34 * asserting the corresponding bit in ICR. 35 */ 36 #define HW_BROADWAY_ICR 0x00 37 #define HW_BROADWAY_IMR 0x04 38 39 40 /* 41 * IRQ chip hooks. 42 * 43 */ 44 45 static void hlwd_pic_mask_and_ack(struct irq_data *d) 46 { 47 int irq = irqd_to_hwirq(d); 48 void __iomem *io_base = irq_data_get_irq_chip_data(d); 49 u32 mask = 1 << irq; 50 51 clrbits32(io_base + HW_BROADWAY_IMR, mask); 52 out_be32(io_base + HW_BROADWAY_ICR, mask); 53 } 54 55 static void hlwd_pic_ack(struct irq_data *d) 56 { 57 int irq = irqd_to_hwirq(d); 58 void __iomem *io_base = irq_data_get_irq_chip_data(d); 59 60 out_be32(io_base + HW_BROADWAY_ICR, 1 << irq); 61 } 62 63 static void hlwd_pic_mask(struct irq_data *d) 64 { 65 int irq = irqd_to_hwirq(d); 66 void __iomem *io_base = irq_data_get_irq_chip_data(d); 67 68 clrbits32(io_base + HW_BROADWAY_IMR, 1 << irq); 69 } 70 71 static void hlwd_pic_unmask(struct irq_data *d) 72 { 73 int irq = irqd_to_hwirq(d); 74 void __iomem *io_base = irq_data_get_irq_chip_data(d); 75 76 setbits32(io_base + HW_BROADWAY_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 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 } 235 236