1 /* 2 * 3 * Programmable Interrupt Controller functions for the Freescale MPC52xx. 4 * 5 * Copyright (C) 2008 Secret Lab Technologies Ltd. 6 * Copyright (C) 2006 bplan GmbH 7 * Copyright (C) 2004 Sylvain Munaut <tnt@246tNt.com> 8 * Copyright (C) 2003 Montavista Software, Inc 9 * 10 * Based on the code from the 2.4 kernel by 11 * Dale Farnsworth <dfarnsworth@mvista.com> and Kent Borg. 12 * 13 * This file is licensed under the terms of the GNU General Public License 14 * version 2. This program is licensed "as is" without any warranty of any 15 * kind, whether express or implied. 16 * 17 */ 18 19 /* 20 * This is the device driver for the MPC5200 interrupt controller. 21 * 22 * hardware overview 23 * ----------------- 24 * The MPC5200 interrupt controller groups the all interrupt sources into 25 * three groups called 'critical', 'main', and 'peripheral'. The critical 26 * group has 3 irqs, External IRQ0, slice timer 0 irq, and wake from deep 27 * sleep. Main group include the other 3 external IRQs, slice timer 1, RTC, 28 * gpios, and the general purpose timers. Peripheral group contains the 29 * remaining irq sources from all of the on-chip peripherals (PSCs, Ethernet, 30 * USB, DMA, etc). 31 * 32 * virqs 33 * ----- 34 * The Linux IRQ subsystem requires that each irq source be assigned a 35 * system wide unique IRQ number starting at 1 (0 means no irq). Since 36 * systems can have multiple interrupt controllers, the virtual IRQ (virq) 37 * infrastructure lets each interrupt controller to define a local set 38 * of IRQ numbers and the virq infrastructure maps those numbers into 39 * a unique range of the global IRQ# space. 40 * 41 * To define a range of virq numbers for this controller, this driver first 42 * assigns a number to each of the irq groups (called the level 1 or L1 43 * value). Within each group individual irq sources are also assigned a 44 * number, as defined by the MPC5200 user guide, and refers to it as the 45 * level 2 or L2 value. The virq number is determined by shifting up the 46 * L1 value by MPC52xx_IRQ_L1_OFFSET and ORing it with the L2 value. 47 * 48 * For example, the TMR0 interrupt is irq 9 in the main group. The 49 * virq for TMR0 is calculated by ((1 << MPC52xx_IRQ_L1_OFFSET) | 9). 50 * 51 * The observant reader will also notice that this driver defines a 4th 52 * interrupt group called 'bestcomm'. The bestcomm group isn't physically 53 * part of the MPC5200 interrupt controller, but it is used here to assign 54 * a separate virq number for each bestcomm task (since any of the 16 55 * bestcomm tasks can cause the bestcomm interrupt to be raised). When a 56 * bestcomm interrupt occurs (peripheral group, irq 0) this driver determines 57 * which task needs servicing and returns the irq number for that task. This 58 * allows drivers which use bestcomm to define their own interrupt handlers. 59 * 60 * irq_chip structures 61 * ------------------- 62 * For actually manipulating IRQs (masking, enabling, clearing, etc) this 63 * driver defines four separate 'irq_chip' structures, one for the main 64 * group, one for the peripherals group, one for the bestcomm group and one 65 * for external interrupts. The irq_chip structures provide the hooks needed 66 * to manipulate each IRQ source, and since each group is has a separate set 67 * of registers for controlling the irq, it makes sense to divide up the 68 * hooks along those lines. 69 * 70 * You'll notice that there is not an irq_chip for the critical group and 71 * you'll also notice that there is an irq_chip defined for external 72 * interrupts even though there is no external interrupt group. The reason 73 * for this is that the four external interrupts are all managed with the same 74 * register even though one of the external IRQs is in the critical group and 75 * the other three are in the main group. For this reason it makes sense for 76 * the 4 external irqs to be managed using a separate set of hooks. The 77 * reason there is no crit irq_chip is that of the 3 irqs in the critical 78 * group, only external interrupt is actually support at this time by this 79 * driver and since external interrupt is the only one used, it can just 80 * be directed to make use of the external irq irq_chip. 81 * 82 * device tree bindings 83 * -------------------- 84 * The device tree bindings for this controller reflect the two level 85 * organization of irqs in the device. #interrupt-cells = <3> where the 86 * first cell is the group number [0..3], the second cell is the irq 87 * number in the group, and the third cell is the sense type (level/edge). 88 * For reference, the following is a list of the interrupt property values 89 * associated with external interrupt sources on the MPC5200 (just because 90 * it is non-obvious to determine what the interrupts property should be 91 * when reading the mpc5200 manual and it is a frequently asked question). 92 * 93 * External interrupts: 94 * <0 0 n> external irq0, n is sense (n=0: level high, 95 * <1 1 n> external irq1, n is sense n=1: edge rising, 96 * <1 2 n> external irq2, n is sense n=2: edge falling, 97 * <1 3 n> external irq3, n is sense n=3: level low) 98 */ 99 #undef DEBUG 100 101 #include <linux/interrupt.h> 102 #include <linux/irq.h> 103 #include <linux/of.h> 104 #include <asm/io.h> 105 #include <asm/prom.h> 106 #include <asm/mpc52xx.h> 107 108 /* HW IRQ mapping */ 109 #define MPC52xx_IRQ_L1_CRIT (0) 110 #define MPC52xx_IRQ_L1_MAIN (1) 111 #define MPC52xx_IRQ_L1_PERP (2) 112 #define MPC52xx_IRQ_L1_SDMA (3) 113 114 #define MPC52xx_IRQ_L1_OFFSET (6) 115 #define MPC52xx_IRQ_L1_MASK (0x00c0) 116 #define MPC52xx_IRQ_L2_MASK (0x003f) 117 118 #define MPC52xx_IRQ_HIGHTESTHWIRQ (0xd0) 119 120 121 /* MPC5200 device tree match tables */ 122 static const struct of_device_id mpc52xx_pic_ids[] __initconst = { 123 { .compatible = "fsl,mpc5200-pic", }, 124 { .compatible = "mpc5200-pic", }, 125 {} 126 }; 127 static const struct of_device_id mpc52xx_sdma_ids[] __initconst = { 128 { .compatible = "fsl,mpc5200-bestcomm", }, 129 { .compatible = "mpc5200-bestcomm", }, 130 {} 131 }; 132 133 static struct mpc52xx_intr __iomem *intr; 134 static struct mpc52xx_sdma __iomem *sdma; 135 static struct irq_domain *mpc52xx_irqhost = NULL; 136 137 static unsigned char mpc52xx_map_senses[4] = { 138 IRQ_TYPE_LEVEL_HIGH, 139 IRQ_TYPE_EDGE_RISING, 140 IRQ_TYPE_EDGE_FALLING, 141 IRQ_TYPE_LEVEL_LOW, 142 }; 143 144 /* Utility functions */ 145 static inline void io_be_setbit(u32 __iomem *addr, int bitno) 146 { 147 out_be32(addr, in_be32(addr) | (1 << bitno)); 148 } 149 150 static inline void io_be_clrbit(u32 __iomem *addr, int bitno) 151 { 152 out_be32(addr, in_be32(addr) & ~(1 << bitno)); 153 } 154 155 /* 156 * IRQ[0-3] interrupt irq_chip 157 */ 158 static void mpc52xx_extirq_mask(struct irq_data *d) 159 { 160 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 161 io_be_clrbit(&intr->ctrl, 11 - l2irq); 162 } 163 164 static void mpc52xx_extirq_unmask(struct irq_data *d) 165 { 166 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 167 io_be_setbit(&intr->ctrl, 11 - l2irq); 168 } 169 170 static void mpc52xx_extirq_ack(struct irq_data *d) 171 { 172 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 173 io_be_setbit(&intr->ctrl, 27-l2irq); 174 } 175 176 static int mpc52xx_extirq_set_type(struct irq_data *d, unsigned int flow_type) 177 { 178 u32 ctrl_reg, type; 179 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 180 void *handler = handle_level_irq; 181 182 pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, 183 (int) irqd_to_hwirq(d), l2irq, flow_type); 184 185 switch (flow_type) { 186 case IRQF_TRIGGER_HIGH: type = 0; break; 187 case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break; 188 case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break; 189 case IRQF_TRIGGER_LOW: type = 3; break; 190 default: 191 type = 0; 192 } 193 194 ctrl_reg = in_be32(&intr->ctrl); 195 ctrl_reg &= ~(0x3 << (22 - (l2irq * 2))); 196 ctrl_reg |= (type << (22 - (l2irq * 2))); 197 out_be32(&intr->ctrl, ctrl_reg); 198 199 __irq_set_handler_locked(d->irq, handler); 200 201 return 0; 202 } 203 204 static struct irq_chip mpc52xx_extirq_irqchip = { 205 .name = "MPC52xx External", 206 .irq_mask = mpc52xx_extirq_mask, 207 .irq_unmask = mpc52xx_extirq_unmask, 208 .irq_ack = mpc52xx_extirq_ack, 209 .irq_set_type = mpc52xx_extirq_set_type, 210 }; 211 212 /* 213 * Main interrupt irq_chip 214 */ 215 static int mpc52xx_null_set_type(struct irq_data *d, unsigned int flow_type) 216 { 217 return 0; /* Do nothing so that the sense mask will get updated */ 218 } 219 220 static void mpc52xx_main_mask(struct irq_data *d) 221 { 222 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 223 io_be_setbit(&intr->main_mask, 16 - l2irq); 224 } 225 226 static void mpc52xx_main_unmask(struct irq_data *d) 227 { 228 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 229 io_be_clrbit(&intr->main_mask, 16 - l2irq); 230 } 231 232 static struct irq_chip mpc52xx_main_irqchip = { 233 .name = "MPC52xx Main", 234 .irq_mask = mpc52xx_main_mask, 235 .irq_mask_ack = mpc52xx_main_mask, 236 .irq_unmask = mpc52xx_main_unmask, 237 .irq_set_type = mpc52xx_null_set_type, 238 }; 239 240 /* 241 * Peripherals interrupt irq_chip 242 */ 243 static void mpc52xx_periph_mask(struct irq_data *d) 244 { 245 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 246 io_be_setbit(&intr->per_mask, 31 - l2irq); 247 } 248 249 static void mpc52xx_periph_unmask(struct irq_data *d) 250 { 251 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 252 io_be_clrbit(&intr->per_mask, 31 - l2irq); 253 } 254 255 static struct irq_chip mpc52xx_periph_irqchip = { 256 .name = "MPC52xx Peripherals", 257 .irq_mask = mpc52xx_periph_mask, 258 .irq_mask_ack = mpc52xx_periph_mask, 259 .irq_unmask = mpc52xx_periph_unmask, 260 .irq_set_type = mpc52xx_null_set_type, 261 }; 262 263 /* 264 * SDMA interrupt irq_chip 265 */ 266 static void mpc52xx_sdma_mask(struct irq_data *d) 267 { 268 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 269 io_be_setbit(&sdma->IntMask, l2irq); 270 } 271 272 static void mpc52xx_sdma_unmask(struct irq_data *d) 273 { 274 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 275 io_be_clrbit(&sdma->IntMask, l2irq); 276 } 277 278 static void mpc52xx_sdma_ack(struct irq_data *d) 279 { 280 int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; 281 out_be32(&sdma->IntPend, 1 << l2irq); 282 } 283 284 static struct irq_chip mpc52xx_sdma_irqchip = { 285 .name = "MPC52xx SDMA", 286 .irq_mask = mpc52xx_sdma_mask, 287 .irq_unmask = mpc52xx_sdma_unmask, 288 .irq_ack = mpc52xx_sdma_ack, 289 .irq_set_type = mpc52xx_null_set_type, 290 }; 291 292 /** 293 * mpc52xx_is_extirq - Returns true if hwirq number is for an external IRQ 294 */ 295 static int mpc52xx_is_extirq(int l1, int l2) 296 { 297 return ((l1 == 0) && (l2 == 0)) || 298 ((l1 == 1) && (l2 >= 1) && (l2 <= 3)); 299 } 300 301 /** 302 * mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property 303 */ 304 static int mpc52xx_irqhost_xlate(struct irq_domain *h, struct device_node *ct, 305 const u32 *intspec, unsigned int intsize, 306 irq_hw_number_t *out_hwirq, 307 unsigned int *out_flags) 308 { 309 int intrvect_l1; 310 int intrvect_l2; 311 int intrvect_type; 312 int intrvect_linux; 313 314 if (intsize != 3) 315 return -1; 316 317 intrvect_l1 = (int)intspec[0]; 318 intrvect_l2 = (int)intspec[1]; 319 intrvect_type = (int)intspec[2] & 0x3; 320 321 intrvect_linux = (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) & 322 MPC52xx_IRQ_L1_MASK; 323 intrvect_linux |= intrvect_l2 & MPC52xx_IRQ_L2_MASK; 324 325 *out_hwirq = intrvect_linux; 326 *out_flags = IRQ_TYPE_LEVEL_LOW; 327 if (mpc52xx_is_extirq(intrvect_l1, intrvect_l2)) 328 *out_flags = mpc52xx_map_senses[intrvect_type]; 329 330 pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1, 331 intrvect_l2); 332 return 0; 333 } 334 335 /** 336 * mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure 337 */ 338 static int mpc52xx_irqhost_map(struct irq_domain *h, unsigned int virq, 339 irq_hw_number_t irq) 340 { 341 int l1irq; 342 int l2irq; 343 struct irq_chip *uninitialized_var(irqchip); 344 void *hndlr; 345 int type; 346 u32 reg; 347 348 l1irq = (irq & MPC52xx_IRQ_L1_MASK) >> MPC52xx_IRQ_L1_OFFSET; 349 l2irq = irq & MPC52xx_IRQ_L2_MASK; 350 351 /* 352 * External IRQs are handled differently by the hardware so they are 353 * handled by a dedicated irq_chip structure. 354 */ 355 if (mpc52xx_is_extirq(l1irq, l2irq)) { 356 reg = in_be32(&intr->ctrl); 357 type = mpc52xx_map_senses[(reg >> (22 - l2irq * 2)) & 0x3]; 358 if ((type == IRQ_TYPE_EDGE_FALLING) || 359 (type == IRQ_TYPE_EDGE_RISING)) 360 hndlr = handle_edge_irq; 361 else 362 hndlr = handle_level_irq; 363 364 irq_set_chip_and_handler(virq, &mpc52xx_extirq_irqchip, hndlr); 365 pr_debug("%s: External IRQ%i virq=%x, hw=%x. type=%x\n", 366 __func__, l2irq, virq, (int)irq, type); 367 return 0; 368 } 369 370 /* It is an internal SOC irq. Choose the correct irq_chip */ 371 switch (l1irq) { 372 case MPC52xx_IRQ_L1_MAIN: irqchip = &mpc52xx_main_irqchip; break; 373 case MPC52xx_IRQ_L1_PERP: irqchip = &mpc52xx_periph_irqchip; break; 374 case MPC52xx_IRQ_L1_SDMA: irqchip = &mpc52xx_sdma_irqchip; break; 375 case MPC52xx_IRQ_L1_CRIT: 376 pr_warn("%s: Critical IRQ #%d is unsupported! Nopping it.\n", 377 __func__, l2irq); 378 irq_set_chip(virq, &no_irq_chip); 379 return 0; 380 } 381 382 irq_set_chip_and_handler(virq, irqchip, handle_level_irq); 383 pr_debug("%s: virq=%x, l1=%i, l2=%i\n", __func__, virq, l1irq, l2irq); 384 385 return 0; 386 } 387 388 static const struct irq_domain_ops mpc52xx_irqhost_ops = { 389 .xlate = mpc52xx_irqhost_xlate, 390 .map = mpc52xx_irqhost_map, 391 }; 392 393 /** 394 * mpc52xx_init_irq - Initialize and register with the virq subsystem 395 * 396 * Hook for setting up IRQs on an mpc5200 system. A pointer to this function 397 * is to be put into the machine definition structure. 398 * 399 * This function searches the device tree for an MPC5200 interrupt controller, 400 * initializes it, and registers it with the virq subsystem. 401 */ 402 void __init mpc52xx_init_irq(void) 403 { 404 u32 intr_ctrl; 405 struct device_node *picnode; 406 struct device_node *np; 407 408 /* Remap the necessary zones */ 409 picnode = of_find_matching_node(NULL, mpc52xx_pic_ids); 410 intr = of_iomap(picnode, 0); 411 if (!intr) 412 panic(__FILE__ ": find_and_map failed on 'mpc5200-pic'. " 413 "Check node !"); 414 415 np = of_find_matching_node(NULL, mpc52xx_sdma_ids); 416 sdma = of_iomap(np, 0); 417 of_node_put(np); 418 if (!sdma) 419 panic(__FILE__ ": find_and_map failed on 'mpc5200-bestcomm'. " 420 "Check node !"); 421 422 pr_debug("MPC5200 IRQ controller mapped to 0x%p\n", intr); 423 424 /* Disable all interrupt sources. */ 425 out_be32(&sdma->IntPend, 0xffffffff); /* 1 means clear pending */ 426 out_be32(&sdma->IntMask, 0xffffffff); /* 1 means disabled */ 427 out_be32(&intr->per_mask, 0x7ffffc00); /* 1 means disabled */ 428 out_be32(&intr->main_mask, 0x00010fff); /* 1 means disabled */ 429 intr_ctrl = in_be32(&intr->ctrl); 430 intr_ctrl &= 0x00ff0000; /* Keeps IRQ[0-3] config */ 431 intr_ctrl |= 0x0f000000 | /* clear IRQ 0-3 */ 432 0x00001000 | /* MEE master external enable */ 433 0x00000000 | /* 0 means disable IRQ 0-3 */ 434 0x00000001; /* CEb route critical normally */ 435 out_be32(&intr->ctrl, intr_ctrl); 436 437 /* Zero a bunch of the priority settings. */ 438 out_be32(&intr->per_pri1, 0); 439 out_be32(&intr->per_pri2, 0); 440 out_be32(&intr->per_pri3, 0); 441 out_be32(&intr->main_pri1, 0); 442 out_be32(&intr->main_pri2, 0); 443 444 /* 445 * As last step, add an irq host to translate the real 446 * hw irq information provided by the ofw to linux virq 447 */ 448 mpc52xx_irqhost = irq_domain_add_linear(picnode, 449 MPC52xx_IRQ_HIGHTESTHWIRQ, 450 &mpc52xx_irqhost_ops, NULL); 451 452 if (!mpc52xx_irqhost) 453 panic(__FILE__ ": Cannot allocate the IRQ host\n"); 454 455 irq_set_default_host(mpc52xx_irqhost); 456 457 pr_info("MPC52xx PIC is up and running!\n"); 458 } 459 460 /** 461 * mpc52xx_get_irq - Get pending interrupt number hook function 462 * 463 * Called by the interrupt handler to determine what IRQ handler needs to be 464 * executed. 465 * 466 * Status of pending interrupts is determined by reading the encoded status 467 * register. The encoded status register has three fields; one for each of the 468 * types of interrupts defined by the controller - 'critical', 'main' and 469 * 'peripheral'. This function reads the status register and returns the IRQ 470 * number associated with the highest priority pending interrupt. 'Critical' 471 * interrupts have the highest priority, followed by 'main' interrupts, and 472 * then 'peripheral'. 473 * 474 * The mpc5200 interrupt controller can be configured to boost the priority 475 * of individual 'peripheral' interrupts. If this is the case then a special 476 * value will appear in either the crit or main fields indicating a high 477 * or medium priority peripheral irq has occurred. 478 * 479 * This function checks each of the 3 irq request fields and returns the 480 * first pending interrupt that it finds. 481 * 482 * This function also identifies a 4th type of interrupt; 'bestcomm'. Each 483 * bestcomm DMA task can raise the bestcomm peripheral interrupt. When this 484 * occurs at task-specific IRQ# is decoded so that each task can have its 485 * own IRQ handler. 486 */ 487 unsigned int mpc52xx_get_irq(void) 488 { 489 u32 status; 490 int irq; 491 492 status = in_be32(&intr->enc_status); 493 if (status & 0x00000400) { /* critical */ 494 irq = (status >> 8) & 0x3; 495 if (irq == 2) /* high priority peripheral */ 496 goto peripheral; 497 irq |= (MPC52xx_IRQ_L1_CRIT << MPC52xx_IRQ_L1_OFFSET); 498 } else if (status & 0x00200000) { /* main */ 499 irq = (status >> 16) & 0x1f; 500 if (irq == 4) /* low priority peripheral */ 501 goto peripheral; 502 irq |= (MPC52xx_IRQ_L1_MAIN << MPC52xx_IRQ_L1_OFFSET); 503 } else if (status & 0x20000000) { /* peripheral */ 504 peripheral: 505 irq = (status >> 24) & 0x1f; 506 if (irq == 0) { /* bestcomm */ 507 status = in_be32(&sdma->IntPend); 508 irq = ffs(status) - 1; 509 irq |= (MPC52xx_IRQ_L1_SDMA << MPC52xx_IRQ_L1_OFFSET); 510 } else { 511 irq |= (MPC52xx_IRQ_L1_PERP << MPC52xx_IRQ_L1_OFFSET); 512 } 513 } else { 514 return NO_IRQ; 515 } 516 517 return irq_linear_revmap(mpc52xx_irqhost, irq); 518 } 519