1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * External Interrupt Controller on Spider South Bridge 4 * 5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005 6 * 7 * Author: Arnd Bergmann <arndb@de.ibm.com> 8 */ 9 10 #include <linux/interrupt.h> 11 #include <linux/irq.h> 12 #include <linux/ioport.h> 13 #include <linux/pgtable.h> 14 15 #include <asm/prom.h> 16 #include <asm/io.h> 17 18 #include "interrupt.h" 19 20 /* register layout taken from Spider spec, table 7.4-4 */ 21 enum { 22 TIR_DEN = 0x004, /* Detection Enable Register */ 23 TIR_MSK = 0x084, /* Mask Level Register */ 24 TIR_EDC = 0x0c0, /* Edge Detection Clear Register */ 25 TIR_PNDA = 0x100, /* Pending Register A */ 26 TIR_PNDB = 0x104, /* Pending Register B */ 27 TIR_CS = 0x144, /* Current Status Register */ 28 TIR_LCSA = 0x150, /* Level Current Status Register A */ 29 TIR_LCSB = 0x154, /* Level Current Status Register B */ 30 TIR_LCSC = 0x158, /* Level Current Status Register C */ 31 TIR_LCSD = 0x15c, /* Level Current Status Register D */ 32 TIR_CFGA = 0x200, /* Setting Register A0 */ 33 TIR_CFGB = 0x204, /* Setting Register B0 */ 34 /* 0x208 ... 0x3ff Setting Register An/Bn */ 35 TIR_PPNDA = 0x400, /* Packet Pending Register A */ 36 TIR_PPNDB = 0x404, /* Packet Pending Register B */ 37 TIR_PIERA = 0x408, /* Packet Output Error Register A */ 38 TIR_PIERB = 0x40c, /* Packet Output Error Register B */ 39 TIR_PIEN = 0x444, /* Packet Output Enable Register */ 40 TIR_PIPND = 0x454, /* Packet Output Pending Register */ 41 TIRDID = 0x484, /* Spider Device ID Register */ 42 REISTIM = 0x500, /* Reissue Command Timeout Time Setting */ 43 REISTIMEN = 0x504, /* Reissue Command Timeout Setting */ 44 REISWAITEN = 0x508, /* Reissue Wait Control*/ 45 }; 46 47 #define SPIDER_CHIP_COUNT 4 48 #define SPIDER_SRC_COUNT 64 49 #define SPIDER_IRQ_INVALID 63 50 51 struct spider_pic { 52 struct irq_domain *host; 53 void __iomem *regs; 54 unsigned int node_id; 55 }; 56 static struct spider_pic spider_pics[SPIDER_CHIP_COUNT]; 57 58 static struct spider_pic *spider_irq_data_to_pic(struct irq_data *d) 59 { 60 return irq_data_get_irq_chip_data(d); 61 } 62 63 static void __iomem *spider_get_irq_config(struct spider_pic *pic, 64 unsigned int src) 65 { 66 return pic->regs + TIR_CFGA + 8 * src; 67 } 68 69 static void spider_unmask_irq(struct irq_data *d) 70 { 71 struct spider_pic *pic = spider_irq_data_to_pic(d); 72 void __iomem *cfg = spider_get_irq_config(pic, irqd_to_hwirq(d)); 73 74 out_be32(cfg, in_be32(cfg) | 0x30000000u); 75 } 76 77 static void spider_mask_irq(struct irq_data *d) 78 { 79 struct spider_pic *pic = spider_irq_data_to_pic(d); 80 void __iomem *cfg = spider_get_irq_config(pic, irqd_to_hwirq(d)); 81 82 out_be32(cfg, in_be32(cfg) & ~0x30000000u); 83 } 84 85 static void spider_ack_irq(struct irq_data *d) 86 { 87 struct spider_pic *pic = spider_irq_data_to_pic(d); 88 unsigned int src = irqd_to_hwirq(d); 89 90 /* Reset edge detection logic if necessary 91 */ 92 if (irqd_is_level_type(d)) 93 return; 94 95 /* Only interrupts 47 to 50 can be set to edge */ 96 if (src < 47 || src > 50) 97 return; 98 99 /* Perform the clear of the edge logic */ 100 out_be32(pic->regs + TIR_EDC, 0x100 | (src & 0xf)); 101 } 102 103 static int spider_set_irq_type(struct irq_data *d, unsigned int type) 104 { 105 unsigned int sense = type & IRQ_TYPE_SENSE_MASK; 106 struct spider_pic *pic = spider_irq_data_to_pic(d); 107 unsigned int hw = irqd_to_hwirq(d); 108 void __iomem *cfg = spider_get_irq_config(pic, hw); 109 u32 old_mask; 110 u32 ic; 111 112 /* Note that only level high is supported for most interrupts */ 113 if (sense != IRQ_TYPE_NONE && sense != IRQ_TYPE_LEVEL_HIGH && 114 (hw < 47 || hw > 50)) 115 return -EINVAL; 116 117 /* Decode sense type */ 118 switch(sense) { 119 case IRQ_TYPE_EDGE_RISING: 120 ic = 0x3; 121 break; 122 case IRQ_TYPE_EDGE_FALLING: 123 ic = 0x2; 124 break; 125 case IRQ_TYPE_LEVEL_LOW: 126 ic = 0x0; 127 break; 128 case IRQ_TYPE_LEVEL_HIGH: 129 case IRQ_TYPE_NONE: 130 ic = 0x1; 131 break; 132 default: 133 return -EINVAL; 134 } 135 136 /* Configure the source. One gross hack that was there before and 137 * that I've kept around is the priority to the BE which I set to 138 * be the same as the interrupt source number. I don't know whether 139 * that's supposed to make any kind of sense however, we'll have to 140 * decide that, but for now, I'm not changing the behaviour. 141 */ 142 old_mask = in_be32(cfg) & 0x30000000u; 143 out_be32(cfg, old_mask | (ic << 24) | (0x7 << 16) | 144 (pic->node_id << 4) | 0xe); 145 out_be32(cfg + 4, (0x2 << 16) | (hw & 0xff)); 146 147 return 0; 148 } 149 150 static struct irq_chip spider_pic = { 151 .name = "SPIDER", 152 .irq_unmask = spider_unmask_irq, 153 .irq_mask = spider_mask_irq, 154 .irq_ack = spider_ack_irq, 155 .irq_set_type = spider_set_irq_type, 156 }; 157 158 static int spider_host_map(struct irq_domain *h, unsigned int virq, 159 irq_hw_number_t hw) 160 { 161 irq_set_chip_data(virq, h->host_data); 162 irq_set_chip_and_handler(virq, &spider_pic, handle_level_irq); 163 164 /* Set default irq type */ 165 irq_set_irq_type(virq, IRQ_TYPE_NONE); 166 167 return 0; 168 } 169 170 static int spider_host_xlate(struct irq_domain *h, struct device_node *ct, 171 const u32 *intspec, unsigned int intsize, 172 irq_hw_number_t *out_hwirq, unsigned int *out_flags) 173 174 { 175 /* Spider interrupts have 2 cells, first is the interrupt source, 176 * second, well, I don't know for sure yet ... We mask the top bits 177 * because old device-trees encode a node number in there 178 */ 179 *out_hwirq = intspec[0] & 0x3f; 180 *out_flags = IRQ_TYPE_LEVEL_HIGH; 181 return 0; 182 } 183 184 static const struct irq_domain_ops spider_host_ops = { 185 .map = spider_host_map, 186 .xlate = spider_host_xlate, 187 }; 188 189 static void spider_irq_cascade(struct irq_desc *desc) 190 { 191 struct irq_chip *chip = irq_desc_get_chip(desc); 192 struct spider_pic *pic = irq_desc_get_handler_data(desc); 193 unsigned int cs, virq; 194 195 cs = in_be32(pic->regs + TIR_CS) >> 24; 196 if (cs == SPIDER_IRQ_INVALID) 197 virq = 0; 198 else 199 virq = irq_linear_revmap(pic->host, cs); 200 201 if (virq) 202 generic_handle_irq(virq); 203 204 chip->irq_eoi(&desc->irq_data); 205 } 206 207 /* For hooking up the cascade we have a problem. Our device-tree is 208 * crap and we don't know on which BE iic interrupt we are hooked on at 209 * least not the "standard" way. We can reconstitute it based on two 210 * informations though: which BE node we are connected to and whether 211 * we are connected to IOIF0 or IOIF1. Right now, we really only care 212 * about the IBM cell blade and we know that its firmware gives us an 213 * interrupt-map property which is pretty strange. 214 */ 215 static unsigned int __init spider_find_cascade_and_node(struct spider_pic *pic) 216 { 217 unsigned int virq; 218 const u32 *imap, *tmp; 219 int imaplen, intsize, unit; 220 struct device_node *iic; 221 struct device_node *of_node; 222 223 of_node = irq_domain_get_of_node(pic->host); 224 225 /* First, we check whether we have a real "interrupts" in the device 226 * tree in case the device-tree is ever fixed 227 */ 228 virq = irq_of_parse_and_map(of_node, 0); 229 if (virq) 230 return virq; 231 232 /* Now do the horrible hacks */ 233 tmp = of_get_property(of_node, "#interrupt-cells", NULL); 234 if (tmp == NULL) 235 return 0; 236 intsize = *tmp; 237 imap = of_get_property(of_node, "interrupt-map", &imaplen); 238 if (imap == NULL || imaplen < (intsize + 1)) 239 return 0; 240 iic = of_find_node_by_phandle(imap[intsize]); 241 if (iic == NULL) 242 return 0; 243 imap += intsize + 1; 244 tmp = of_get_property(iic, "#interrupt-cells", NULL); 245 if (tmp == NULL) { 246 of_node_put(iic); 247 return 0; 248 } 249 intsize = *tmp; 250 /* Assume unit is last entry of interrupt specifier */ 251 unit = imap[intsize - 1]; 252 /* Ok, we have a unit, now let's try to get the node */ 253 tmp = of_get_property(iic, "ibm,interrupt-server-ranges", NULL); 254 if (tmp == NULL) { 255 of_node_put(iic); 256 return 0; 257 } 258 /* ugly as hell but works for now */ 259 pic->node_id = (*tmp) >> 1; 260 of_node_put(iic); 261 262 /* Ok, now let's get cracking. You may ask me why I just didn't match 263 * the iic host from the iic OF node, but that way I'm still compatible 264 * with really really old old firmwares for which we don't have a node 265 */ 266 /* Manufacture an IIC interrupt number of class 2 */ 267 virq = irq_create_mapping(NULL, 268 (pic->node_id << IIC_IRQ_NODE_SHIFT) | 269 (2 << IIC_IRQ_CLASS_SHIFT) | 270 unit); 271 if (!virq) 272 printk(KERN_ERR "spider_pic: failed to map cascade !"); 273 return virq; 274 } 275 276 277 static void __init spider_init_one(struct device_node *of_node, int chip, 278 unsigned long addr) 279 { 280 struct spider_pic *pic = &spider_pics[chip]; 281 int i, virq; 282 283 /* Map registers */ 284 pic->regs = ioremap(addr, 0x1000); 285 if (pic->regs == NULL) 286 panic("spider_pic: can't map registers !"); 287 288 /* Allocate a host */ 289 pic->host = irq_domain_add_linear(of_node, SPIDER_SRC_COUNT, 290 &spider_host_ops, pic); 291 if (pic->host == NULL) 292 panic("spider_pic: can't allocate irq host !"); 293 294 /* Go through all sources and disable them */ 295 for (i = 0; i < SPIDER_SRC_COUNT; i++) { 296 void __iomem *cfg = pic->regs + TIR_CFGA + 8 * i; 297 out_be32(cfg, in_be32(cfg) & ~0x30000000u); 298 } 299 300 /* do not mask any interrupts because of level */ 301 out_be32(pic->regs + TIR_MSK, 0x0); 302 303 /* enable interrupt packets to be output */ 304 out_be32(pic->regs + TIR_PIEN, in_be32(pic->regs + TIR_PIEN) | 0x1); 305 306 /* Hook up the cascade interrupt to the iic and nodeid */ 307 virq = spider_find_cascade_and_node(pic); 308 if (!virq) 309 return; 310 irq_set_handler_data(virq, pic); 311 irq_set_chained_handler(virq, spider_irq_cascade); 312 313 printk(KERN_INFO "spider_pic: node %d, addr: 0x%lx %pOF\n", 314 pic->node_id, addr, of_node); 315 316 /* Enable the interrupt detection enable bit. Do this last! */ 317 out_be32(pic->regs + TIR_DEN, in_be32(pic->regs + TIR_DEN) | 0x1); 318 } 319 320 void __init spider_init_IRQ(void) 321 { 322 struct resource r; 323 struct device_node *dn; 324 int chip = 0; 325 326 /* XXX node numbers are totally bogus. We _hope_ we get the device 327 * nodes in the right order here but that's definitely not guaranteed, 328 * we need to get the node from the device tree instead. 329 * There is currently no proper property for it (but our whole 330 * device-tree is bogus anyway) so all we can do is pray or maybe test 331 * the address and deduce the node-id 332 */ 333 for_each_node_by_name(dn, "interrupt-controller") { 334 if (of_device_is_compatible(dn, "CBEA,platform-spider-pic")) { 335 if (of_address_to_resource(dn, 0, &r)) { 336 printk(KERN_WARNING "spider-pic: Failed\n"); 337 continue; 338 } 339 } else if (of_device_is_compatible(dn, "sti,platform-spider-pic") 340 && (chip < 2)) { 341 static long hard_coded_pics[] = 342 { 0x24000008000ul, 0x34000008000ul}; 343 r.start = hard_coded_pics[chip]; 344 } else 345 continue; 346 spider_init_one(dn, chip++, r.start); 347 } 348 } 349