drivers/soc/fsl/qe/qe_ic.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * arch/powerpc/sysdev/qe_lib/qe_ic.c
   4  *
   5  * Copyright (C) 2006 Freescale Semiconductor, Inc.  All rights reserved.
   6  *
   7  * Author: Li Yang <leoli@freescale.com>
   8  * Based on code from Shlomi Gridish <gridish@freescale.com>
   9  *
  10  * QUICC ENGINE Interrupt Controller
  11  */
  12
  13 #include <linux/of_irq.h>
  14 #include <linux/of_address.h>
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/errno.h>
  18 #include <linux/irq.h>
  19 #include <linux/reboot.h>
  20 #include <linux/slab.h>
  21 #include <linux/stddef.h>
  22 #include <linux/sched.h>
  23 #include <linux/signal.h>
  24 #include <linux/device.h>
  25 #include <linux/spinlock.h>
  26 #include <asm/irq.h>
  27 #include <asm/io.h>
  28 #include <soc/fsl/qe/qe.h>
  29
  30 #define NR_QE_IC_INTS           64
  31
  32 /* QE IC registers offset */
  33 #define QEIC_CICR               0x00
  34 #define QEIC_CIVEC              0x04
  35 #define QEIC_CIPXCC             0x10
  36 #define QEIC_CIPYCC             0x14
  37 #define QEIC_CIPWCC             0x18
  38 #define QEIC_CIPZCC             0x1c
  39 #define QEIC_CIMR               0x20
  40 #define QEIC_CRIMR              0x24
  41 #define QEIC_CIPRTA             0x30
  42 #define QEIC_CIPRTB             0x34
  43 #define QEIC_CHIVEC             0x60
  44
  45 struct qe_ic {
  46         /* Control registers offset */
  47         __be32 __iomem *regs;
  48
  49         /* The remapper for this QEIC */
  50         struct irq_domain *irqhost;
  51
  52         /* The "linux" controller struct */
  53         struct irq_chip hc_irq;
  54
  55         /* VIRQ numbers of QE high/low irqs */
  56         unsigned int virq_high;
  57         unsigned int virq_low;
  58 };
  59
  60 /*
  61  * QE interrupt controller internal structure
  62  */
  63 struct qe_ic_info {
  64         /* Location of this source at the QIMR register */
  65         u32     mask;
  66
  67         /* Mask register offset */
  68         u32     mask_reg;
  69
  70         /*
  71          * For grouped interrupts sources - the interrupt code as
  72          * appears at the group priority register
  73          */
  74         u8      pri_code;
  75
  76         /* Group priority register offset */
  77         u32     pri_reg;
  78 };
  79
  80 static DEFINE_RAW_SPINLOCK(qe_ic_lock);
  81
  82 static struct qe_ic_info qe_ic_info[] = {
  83         [1] = {
  84                .mask = 0x00008000,
  85                .mask_reg = QEIC_CIMR,
  86                .pri_code = 0,
  87                .pri_reg = QEIC_CIPWCC,
  88                },
  89         [2] = {
  90                .mask = 0x00004000,
  91                .mask_reg = QEIC_CIMR,
  92                .pri_code = 1,
  93                .pri_reg = QEIC_CIPWCC,
  94                },
  95         [3] = {
  96                .mask = 0x00002000,
  97                .mask_reg = QEIC_CIMR,
  98                .pri_code = 2,
  99                .pri_reg = QEIC_CIPWCC,
 100                },
 101         [10] = {
 102                 .mask = 0x00000040,
 103                 .mask_reg = QEIC_CIMR,
 104                 .pri_code = 1,
 105                 .pri_reg = QEIC_CIPZCC,
 106                 },
 107         [11] = {
 108                 .mask = 0x00000020,
 109                 .mask_reg = QEIC_CIMR,
 110                 .pri_code = 2,
 111                 .pri_reg = QEIC_CIPZCC,
 112                 },
 113         [12] = {
 114                 .mask = 0x00000010,
 115                 .mask_reg = QEIC_CIMR,
 116                 .pri_code = 3,
 117                 .pri_reg = QEIC_CIPZCC,
 118                 },
 119         [13] = {
 120                 .mask = 0x00000008,
 121                 .mask_reg = QEIC_CIMR,
 122                 .pri_code = 4,
 123                 .pri_reg = QEIC_CIPZCC,
 124                 },
 125         [14] = {
 126                 .mask = 0x00000004,
 127                 .mask_reg = QEIC_CIMR,
 128                 .pri_code = 5,
 129                 .pri_reg = QEIC_CIPZCC,
 130                 },
 131         [15] = {
 132                 .mask = 0x00000002,
 133                 .mask_reg = QEIC_CIMR,
 134                 .pri_code = 6,
 135                 .pri_reg = QEIC_CIPZCC,
 136                 },
 137         [20] = {
 138                 .mask = 0x10000000,
 139                 .mask_reg = QEIC_CRIMR,
 140                 .pri_code = 3,
 141                 .pri_reg = QEIC_CIPRTA,
 142                 },
 143         [25] = {
 144                 .mask = 0x00800000,
 145                 .mask_reg = QEIC_CRIMR,
 146                 .pri_code = 0,
 147                 .pri_reg = QEIC_CIPRTB,
 148                 },
 149         [26] = {
 150                 .mask = 0x00400000,
 151                 .mask_reg = QEIC_CRIMR,
 152                 .pri_code = 1,
 153                 .pri_reg = QEIC_CIPRTB,
 154                 },
 155         [27] = {
 156                 .mask = 0x00200000,
 157                 .mask_reg = QEIC_CRIMR,
 158                 .pri_code = 2,
 159                 .pri_reg = QEIC_CIPRTB,
 160                 },
 161         [28] = {
 162                 .mask = 0x00100000,
 163                 .mask_reg = QEIC_CRIMR,
 164                 .pri_code = 3,
 165                 .pri_reg = QEIC_CIPRTB,
 166                 },
 167         [32] = {
 168                 .mask = 0x80000000,
 169                 .mask_reg = QEIC_CIMR,
 170                 .pri_code = 0,
 171                 .pri_reg = QEIC_CIPXCC,
 172                 },
 173         [33] = {
 174                 .mask = 0x40000000,
 175                 .mask_reg = QEIC_CIMR,
 176                 .pri_code = 1,
 177                 .pri_reg = QEIC_CIPXCC,
 178                 },
 179         [34] = {
 180                 .mask = 0x20000000,
 181                 .mask_reg = QEIC_CIMR,
 182                 .pri_code = 2,
 183                 .pri_reg = QEIC_CIPXCC,
 184                 },
 185         [35] = {
 186                 .mask = 0x10000000,
 187                 .mask_reg = QEIC_CIMR,
 188                 .pri_code = 3,
 189                 .pri_reg = QEIC_CIPXCC,
 190                 },
 191         [36] = {
 192                 .mask = 0x08000000,
 193                 .mask_reg = QEIC_CIMR,
 194                 .pri_code = 4,
 195                 .pri_reg = QEIC_CIPXCC,
 196                 },
 197         [40] = {
 198                 .mask = 0x00800000,
 199                 .mask_reg = QEIC_CIMR,
 200                 .pri_code = 0,
 201                 .pri_reg = QEIC_CIPYCC,
 202                 },
 203         [41] = {
 204                 .mask = 0x00400000,
 205                 .mask_reg = QEIC_CIMR,
 206                 .pri_code = 1,
 207                 .pri_reg = QEIC_CIPYCC,
 208                 },
 209         [42] = {
 210                 .mask = 0x00200000,
 211                 .mask_reg = QEIC_CIMR,
 212                 .pri_code = 2,
 213                 .pri_reg = QEIC_CIPYCC,
 214                 },
 215         [43] = {
 216                 .mask = 0x00100000,
 217                 .mask_reg = QEIC_CIMR,
 218                 .pri_code = 3,
 219                 .pri_reg = QEIC_CIPYCC,
 220                 },
 221 };
 222
 223 static inline u32 qe_ic_read(__be32  __iomem *base, unsigned int reg)
 224 {
 225         return ioread32be(base + (reg >> 2));
 226 }
 227
 228 static inline void qe_ic_write(__be32  __iomem *base, unsigned int reg,
 229                                u32 value)
 230 {
 231         iowrite32be(value, base + (reg >> 2));
 232 }
 233
 234 static inline struct qe_ic *qe_ic_from_irq(unsigned int virq)
 235 {
 236         return irq_get_chip_data(virq);
 237 }
 238
 239 static inline struct qe_ic *qe_ic_from_irq_data(struct irq_data *d)
 240 {
 241         return irq_data_get_irq_chip_data(d);
 242 }
 243
 244 static void qe_ic_unmask_irq(struct irq_data *d)
 245 {
 246         struct qe_ic *qe_ic = qe_ic_from_irq_data(d);
 247         unsigned int src = irqd_to_hwirq(d);
 248         unsigned long flags;
 249         u32 temp;
 250
 251         raw_spin_lock_irqsave(&qe_ic_lock, flags);
 252
 253         temp = qe_ic_read(qe_ic->regs, qe_ic_info[src].mask_reg);
 254         qe_ic_write(qe_ic->regs, qe_ic_info[src].mask_reg,
 255                     temp | qe_ic_info[src].mask);
 256
 257         raw_spin_unlock_irqrestore(&qe_ic_lock, flags);
 258 }
 259
 260 static void qe_ic_mask_irq(struct irq_data *d)
 261 {
 262         struct qe_ic *qe_ic = qe_ic_from_irq_data(d);
 263         unsigned int src = irqd_to_hwirq(d);
 264         unsigned long flags;
 265         u32 temp;
 266
 267         raw_spin_lock_irqsave(&qe_ic_lock, flags);
 268
 269         temp = qe_ic_read(qe_ic->regs, qe_ic_info[src].mask_reg);
 270         qe_ic_write(qe_ic->regs, qe_ic_info[src].mask_reg,
 271                     temp & ~qe_ic_info[src].mask);
 272
 273         /* Flush the above write before enabling interrupts; otherwise,
 274          * spurious interrupts will sometimes happen.  To be 100% sure
 275          * that the write has reached the device before interrupts are
 276          * enabled, the mask register would have to be read back; however,
 277          * this is not required for correctness, only to avoid wasting
 278          * time on a large number of spurious interrupts.  In testing,
 279          * a sync reduced the observed spurious interrupts to zero.
 280          */
 281         mb();
 282
 283         raw_spin_unlock_irqrestore(&qe_ic_lock, flags);
 284 }
 285
 286 static struct irq_chip qe_ic_irq_chip = {
 287         .name = "QEIC",
 288         .irq_unmask = qe_ic_unmask_irq,
 289         .irq_mask = qe_ic_mask_irq,
 290         .irq_mask_ack = qe_ic_mask_irq,
 291 };
 292
 293 static int qe_ic_host_match(struct irq_domain *h, struct device_node *node,
 294                             enum irq_domain_bus_token bus_token)
 295 {
 296         /* Exact match, unless qe_ic node is NULL */
 297         struct device_node *of_node = irq_domain_get_of_node(h);
 298         return of_node == NULL || of_node == node;
 299 }
 300
 301 static int qe_ic_host_map(struct irq_domain *h, unsigned int virq,
 302                           irq_hw_number_t hw)
 303 {
 304         struct qe_ic *qe_ic = h->host_data;
 305         struct irq_chip *chip;
 306
 307         if (hw >= ARRAY_SIZE(qe_ic_info)) {
 308                 pr_err("%s: Invalid hw irq number for QEIC\n", __func__);
 309                 return -EINVAL;
 310         }
 311
 312         if (qe_ic_info[hw].mask == 0) {
 313                 printk(KERN_ERR "Can't map reserved IRQ\n");
 314                 return -EINVAL;
 315         }
 316         /* Default chip */
 317         chip = &qe_ic->hc_irq;
 318
 319         irq_set_chip_data(virq, qe_ic);
 320         irq_set_status_flags(virq, IRQ_LEVEL);
 321
 322         irq_set_chip_and_handler(virq, chip, handle_level_irq);
 323
 324         return 0;
 325 }
 326
 327 static const struct irq_domain_ops qe_ic_host_ops = {
 328         .match = qe_ic_host_match,
 329         .map = qe_ic_host_map,
 330         .xlate = irq_domain_xlate_onetwocell,
 331 };
 332
 333 /* Return an interrupt vector or 0 if no interrupt is pending. */
 334 static unsigned int qe_ic_get_low_irq(struct qe_ic *qe_ic)
 335 {
 336         int irq;
 337
 338         BUG_ON(qe_ic == NULL);
 339
 340         /* get the interrupt source vector. */
 341         irq = qe_ic_read(qe_ic->regs, QEIC_CIVEC) >> 26;
 342
 343         if (irq == 0)
 344                 return 0;
 345
 346         return irq_linear_revmap(qe_ic->irqhost, irq);
 347 }
 348
 349 /* Return an interrupt vector or 0 if no interrupt is pending. */
 350 static unsigned int qe_ic_get_high_irq(struct qe_ic *qe_ic)
 351 {
 352         int irq;
 353
 354         BUG_ON(qe_ic == NULL);
 355
 356         /* get the interrupt source vector. */
 357         irq = qe_ic_read(qe_ic->regs, QEIC_CHIVEC) >> 26;
 358
 359         if (irq == 0)
 360                 return 0;
 361
 362         return irq_linear_revmap(qe_ic->irqhost, irq);
 363 }
 364
 365 static void qe_ic_cascade_low(struct irq_desc *desc)
 366 {
 367         struct qe_ic *qe_ic = irq_desc_get_handler_data(desc);
 368         unsigned int cascade_irq = qe_ic_get_low_irq(qe_ic);
 369         struct irq_chip *chip = irq_desc_get_chip(desc);
 370
 371         if (cascade_irq != 0)
 372                 generic_handle_irq(cascade_irq);
 373
 374         if (chip->irq_eoi)
 375                 chip->irq_eoi(&desc->irq_data);
 376 }
 377
 378 static void qe_ic_cascade_high(struct irq_desc *desc)
 379 {
 380         struct qe_ic *qe_ic = irq_desc_get_handler_data(desc);
 381         unsigned int cascade_irq = qe_ic_get_high_irq(qe_ic);
 382         struct irq_chip *chip = irq_desc_get_chip(desc);
 383
 384         if (cascade_irq != 0)
 385                 generic_handle_irq(cascade_irq);
 386
 387         if (chip->irq_eoi)
 388                 chip->irq_eoi(&desc->irq_data);
 389 }
 390
 391 static void qe_ic_cascade_muxed_mpic(struct irq_desc *desc)
 392 {
 393         struct qe_ic *qe_ic = irq_desc_get_handler_data(desc);
 394         unsigned int cascade_irq;
 395         struct irq_chip *chip = irq_desc_get_chip(desc);
 396
 397         cascade_irq = qe_ic_get_high_irq(qe_ic);
 398         if (cascade_irq == 0)
 399                 cascade_irq = qe_ic_get_low_irq(qe_ic);
 400
 401         if (cascade_irq != 0)
 402                 generic_handle_irq(cascade_irq);
 403
 404         chip->irq_eoi(&desc->irq_data);
 405 }
 406
 407 static void __init qe_ic_init(struct device_node *node)
 408 {
 409         void (*low_handler)(struct irq_desc *desc);
 410         void (*high_handler)(struct irq_desc *desc);
 411         struct qe_ic *qe_ic;
 412         struct resource res;
 413         u32 ret;
 414
 415         ret = of_address_to_resource(node, 0, &res);
 416         if (ret)
 417                 return;
 418
 419         qe_ic = kzalloc(sizeof(*qe_ic), GFP_KERNEL);
 420         if (qe_ic == NULL)
 421                 return;
 422
 423         qe_ic->irqhost = irq_domain_add_linear(node, NR_QE_IC_INTS,
 424                                                &qe_ic_host_ops, qe_ic);
 425         if (qe_ic->irqhost == NULL) {
 426                 kfree(qe_ic);
 427                 return;
 428         }
 429
 430         qe_ic->regs = ioremap(res.start, resource_size(&res));
 431
 432         qe_ic->hc_irq = qe_ic_irq_chip;
 433
 434         qe_ic->virq_high = irq_of_parse_and_map(node, 0);
 435         qe_ic->virq_low = irq_of_parse_and_map(node, 1);
 436
 437         if (!qe_ic->virq_low) {
 438                 printk(KERN_ERR "Failed to map QE_IC low IRQ\n");
 439                 kfree(qe_ic);
 440                 return;
 441         }
 442         if (qe_ic->virq_high != qe_ic->virq_low) {
 443                 low_handler = qe_ic_cascade_low;
 444                 high_handler = qe_ic_cascade_high;
 445         } else {
 446                 low_handler = qe_ic_cascade_muxed_mpic;
 447                 high_handler = NULL;
 448         }
 449
 450         qe_ic_write(qe_ic->regs, QEIC_CICR, 0);
 451
 452         irq_set_handler_data(qe_ic->virq_low, qe_ic);
 453         irq_set_chained_handler(qe_ic->virq_low, low_handler);
 454
 455         if (qe_ic->virq_high && qe_ic->virq_high != qe_ic->virq_low) {
 456                 irq_set_handler_data(qe_ic->virq_high, qe_ic);
 457                 irq_set_chained_handler(qe_ic->virq_high, high_handler);
 458         }
 459 }
 460
 461 static int __init qe_ic_of_init(void)
 462 {
 463         struct device_node *np;
 464
 465         np = of_find_compatible_node(NULL, NULL, "fsl,qe-ic");
 466         if (!np) {
 467                 np = of_find_node_by_type(NULL, "qeic");
 468                 if (!np)
 469                         return -ENODEV;
 470         }
 471         qe_ic_init(np);
 472         of_node_put(np);
 473         return 0;
 474 }
 475 subsys_initcall(qe_ic_of_init);