1/* 2 * OSS handling 3 * Written by Joshua M. Thompson (funaho@jurai.org) 4 * 5 * 6 * This chip is used in the IIfx in place of VIA #2. It acts like a fancy 7 * VIA chip with prorammable interrupt levels. 8 * 9 * 990502 (jmt) - Major rewrite for new interrupt architecture as well as some 10 * recent insights into OSS operational details. 11 * 990610 (jmt) - Now taking full advantage of the OSS. Interrupts are mapped 12 * to mostly match the A/UX interrupt scheme supported on the 13 * VIA side. Also added support for enabling the ISM irq again 14 * since we now have a functional IOP manager. 15 */ 16 17#include <linux/types.h> 18#include <linux/kernel.h> 19#include <linux/mm.h> 20#include <linux/delay.h> 21#include <linux/init.h> 22 23#include <asm/bootinfo.h> 24#include <asm/macintosh.h> 25#include <asm/macints.h> 26#include <asm/mac_via.h> 27#include <asm/mac_oss.h> 28 29int oss_present; 30volatile struct mac_oss *oss; 31 32static irqreturn_t oss_irq(int, void *); 33static irqreturn_t oss_nubus_irq(int, void *); 34 35extern irqreturn_t via1_irq(int, void *); 36 37/* 38 * Initialize the OSS 39 * 40 * The OSS "detection" code is actually in via_init() which is always called 41 * before us. Thus we can count on oss_present being valid on entry. 42 */ 43 44void __init oss_init(void) 45{ 46 int i; 47 48 if (!oss_present) return; 49 50 oss = (struct mac_oss *) OSS_BASE; 51 52 /* Disable all interrupts. Unlike a VIA it looks like we */ 53 /* do this by setting the source's interrupt level to zero. */ 54 55 for (i = 0; i <= OSS_NUM_SOURCES; i++) { 56 oss->irq_level[i] = OSS_IRQLEV_DISABLED; 57 } 58 /* If we disable VIA1 here, we never really handle it... */ 59 oss->irq_level[OSS_VIA1] = OSS_IRQLEV_VIA1; 60} 61 62/* 63 * Register the OSS and NuBus interrupt dispatchers. 64 */ 65 66void __init oss_register_interrupts(void) 67{ 68 if (request_irq(OSS_IRQLEV_SCSI, oss_irq, IRQ_FLG_LOCK, 69 "scsi", (void *) oss)) 70 pr_err("Couldn't register %s interrupt\n", "scsi"); 71 if (request_irq(OSS_IRQLEV_NUBUS, oss_nubus_irq, IRQ_FLG_LOCK, 72 "nubus", (void *) oss)) 73 pr_err("Couldn't register %s interrupt\n", "nubus"); 74 if (request_irq(OSS_IRQLEV_SOUND, oss_irq, IRQ_FLG_LOCK, 75 "sound", (void *) oss)) 76 pr_err("Couldn't register %s interrupt\n", "sound"); 77 if (request_irq(OSS_IRQLEV_VIA1, via1_irq, IRQ_FLG_LOCK, 78 "via1", (void *) via1)) 79 pr_err("Couldn't register %s interrupt\n", "via1"); 80} 81 82/* 83 * Initialize OSS for Nubus access 84 */ 85 86void __init oss_nubus_init(void) 87{ 88} 89 90/* 91 * Handle miscellaneous OSS interrupts. Right now that's just sound 92 * and SCSI; everything else is routed to its own autovector IRQ. 93 */ 94 95static irqreturn_t oss_irq(int irq, void *dev_id) 96{ 97 int events; 98 99 events = oss->irq_pending & (OSS_IP_SOUND|OSS_IP_SCSI); 100 if (!events) 101 return IRQ_NONE; 102 103#ifdef DEBUG_IRQS 104 if ((console_loglevel == 10) && !(events & OSS_IP_SCSI)) { 105 printk("oss_irq: irq %d events = 0x%04X\n", irq, 106 (int) oss->irq_pending); 107 } 108#endif 109 110 if (events & OSS_IP_SOUND) { 111 oss->irq_pending &= ~OSS_IP_SOUND; 112 } else if (events & OSS_IP_SCSI) { 113 oss->irq_pending &= ~OSS_IP_SCSI; 114 m68k_handle_int(IRQ_MAC_SCSI); 115 } else { 116 } 117 return IRQ_HANDLED; 118} 119 120/* 121 * Nubus IRQ handler, OSS style 122 * 123 * Unlike the VIA/RBV this is on its own autovector interrupt level. 124 */ 125 126static irqreturn_t oss_nubus_irq(int irq, void *dev_id) 127{ 128 int events, irq_bit, i; 129 130 events = oss->irq_pending & OSS_IP_NUBUS; 131 if (!events) 132 return IRQ_NONE; 133 134#ifdef DEBUG_NUBUS_INT 135 if (console_loglevel > 7) { 136 printk("oss_nubus_irq: events = 0x%04X\n", events); 137 } 138#endif 139 /* There are only six slots on the OSS, not seven */ 140 141 i = 6; 142 irq_bit = 0x40; 143 do { 144 --i; 145 irq_bit >>= 1; 146 if (events & irq_bit) { 147 oss->irq_pending &= ~irq_bit; 148 m68k_handle_int(NUBUS_SOURCE_BASE + i); 149 } 150 } while(events & (irq_bit - 1)); 151 return IRQ_HANDLED; 152} 153 154/* 155 * Enable an OSS interrupt 156 * 157 * It looks messy but it's rather straightforward. The switch() statement 158 * just maps the machspec interrupt numbers to the right OSS interrupt 159 * source (if the OSS handles that interrupt) and then sets the interrupt 160 * level for that source to nonzero, thus enabling the interrupt. 161 */ 162 163void oss_irq_enable(int irq) { 164#ifdef DEBUG_IRQUSE 165 printk("oss_irq_enable(%d)\n", irq); 166#endif 167 switch(irq) { 168 case IRQ_MAC_SCC: 169 oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_IOPSCC; 170 break; 171 case IRQ_MAC_ADB: 172 oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_IOPISM; 173 break; 174 case IRQ_MAC_SCSI: 175 oss->irq_level[OSS_SCSI] = OSS_IRQLEV_SCSI; 176 break; 177 case IRQ_NUBUS_9: 178 case IRQ_NUBUS_A: 179 case IRQ_NUBUS_B: 180 case IRQ_NUBUS_C: 181 case IRQ_NUBUS_D: 182 case IRQ_NUBUS_E: 183 irq -= NUBUS_SOURCE_BASE; 184 oss->irq_level[irq] = OSS_IRQLEV_NUBUS; 185 break; 186#ifdef DEBUG_IRQUSE 187 default: 188 printk("%s unknown irq %d\n", __func__, irq); 189 break; 190#endif 191 } 192} 193 194/* 195 * Disable an OSS interrupt 196 * 197 * Same as above except we set the source's interrupt level to zero, 198 * to disable the interrupt. 199 */ 200 201void oss_irq_disable(int irq) { 202#ifdef DEBUG_IRQUSE 203 printk("oss_irq_disable(%d)\n", irq); 204#endif 205 switch(irq) { 206 case IRQ_MAC_SCC: 207 oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_DISABLED; 208 break; 209 case IRQ_MAC_ADB: 210 oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_DISABLED; 211 break; 212 case IRQ_MAC_SCSI: 213 oss->irq_level[OSS_SCSI] = OSS_IRQLEV_DISABLED; 214 break; 215 case IRQ_NUBUS_9: 216 case IRQ_NUBUS_A: 217 case IRQ_NUBUS_B: 218 case IRQ_NUBUS_C: 219 case IRQ_NUBUS_D: 220 case IRQ_NUBUS_E: 221 irq -= NUBUS_SOURCE_BASE; 222 oss->irq_level[irq] = OSS_IRQLEV_DISABLED; 223 break; 224#ifdef DEBUG_IRQUSE 225 default: 226 printk("%s unknown irq %d\n", __func__, irq); 227 break; 228#endif 229 } 230} 231 232/* 233 * Clear an OSS interrupt 234 * 235 * Not sure if this works or not but it's the only method I could 236 * think of based on the contents of the mac_oss structure. 237 */ 238 239void oss_irq_clear(int irq) { 240 switch(irq) { 241 case IRQ_MAC_SCC: 242 oss->irq_pending &= ~OSS_IP_IOPSCC; 243 break; 244 case IRQ_MAC_ADB: 245 oss->irq_pending &= ~OSS_IP_IOPISM; 246 break; 247 case IRQ_MAC_SCSI: 248 oss->irq_pending &= ~OSS_IP_SCSI; 249 break; 250 case IRQ_NUBUS_9: 251 case IRQ_NUBUS_A: 252 case IRQ_NUBUS_B: 253 case IRQ_NUBUS_C: 254 case IRQ_NUBUS_D: 255 case IRQ_NUBUS_E: 256 irq -= NUBUS_SOURCE_BASE; 257 oss->irq_pending &= ~(1 << irq); 258 break; 259 } 260} 261 262/* 263 * Check to see if a specific OSS interrupt is pending 264 */ 265 266int oss_irq_pending(int irq) 267{ 268 switch(irq) { 269 case IRQ_MAC_SCC: 270 return oss->irq_pending & OSS_IP_IOPSCC; 271 break; 272 case IRQ_MAC_ADB: 273 return oss->irq_pending & OSS_IP_IOPISM; 274 break; 275 case IRQ_MAC_SCSI: 276 return oss->irq_pending & OSS_IP_SCSI; 277 break; 278 case IRQ_NUBUS_9: 279 case IRQ_NUBUS_A: 280 case IRQ_NUBUS_B: 281 case IRQ_NUBUS_C: 282 case IRQ_NUBUS_D: 283 case IRQ_NUBUS_E: 284 irq -= NUBUS_SOURCE_BASE; 285 return oss->irq_pending & (1 << irq); 286 break; 287 } 288 return 0; 289} 290