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 } 256 257