drivers/irqchip/irq-ixp4xx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * irqchip for the IXP4xx interrupt controller
   4  * Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org>
   5  *
   6  * Based on arch/arm/mach-ixp4xx/common.c
   7  * Copyright 2002 (C) Intel Corporation
   8  * Copyright 2003-2004 (C) MontaVista, Software, Inc.
   9  * Copyright (C) Deepak Saxena <dsaxena@plexity.net>
  10  */
  11 #include <linux/bitops.h>
  12 #include <linux/gpio/driver.h>
  13 #include <linux/irq.h>
  14 #include <linux/io.h>
  15 #include <linux/irqchip.h>
  16 #include <linux/irqchip/irq-ixp4xx.h>
  17 #include <linux/irqdomain.h>
  18 #include <linux/of.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_irq.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/cpu.h>
  23
  24 #include <asm/exception.h>
  25 #include <asm/mach/irq.h>
  26
  27 #define IXP4XX_ICPR     0x00 /* Interrupt Status */
  28 #define IXP4XX_ICMR     0x04 /* Interrupt Enable */
  29 #define IXP4XX_ICLR     0x08 /* Interrupt IRQ/FIQ Select */
  30 #define IXP4XX_ICIP     0x0C /* IRQ Status */
  31 #define IXP4XX_ICFP     0x10 /* FIQ Status */
  32 #define IXP4XX_ICHR     0x14 /* Interrupt Priority */
  33 #define IXP4XX_ICIH     0x18 /* IRQ Highest Pri Int */
  34 #define IXP4XX_ICFH     0x1C /* FIQ Highest Pri Int */
  35
  36 /* IXP43x and IXP46x-only */
  37 #define IXP4XX_ICPR2    0x20 /* Interrupt Status 2 */
  38 #define IXP4XX_ICMR2    0x24 /* Interrupt Enable 2 */
  39 #define IXP4XX_ICLR2    0x28 /* Interrupt IRQ/FIQ Select 2 */
  40 #define IXP4XX_ICIP2    0x2C /* IRQ Status */
  41 #define IXP4XX_ICFP2    0x30 /* FIQ Status */
  42 #define IXP4XX_ICEEN    0x34 /* Error High Pri Enable */
  43
  44 /**
  45  * struct ixp4xx_irq - state container for the Faraday IRQ controller
  46  * @irqbase: IRQ controller memory base in virtual memory
  47  * @is_356: if this is an IXP43x, IXP45x or IX46x SoC (with 64 IRQs)
  48  * @irqchip: irqchip for this instance
  49  * @domain: IRQ domain for this instance
  50  */
  51 struct ixp4xx_irq {
  52         void __iomem *irqbase;
  53         bool is_356;
  54         struct irq_chip irqchip;
  55         struct irq_domain *domain;
  56 };
  57
  58 /* Local static state container */
  59 static struct ixp4xx_irq ixirq;
  60
  61 /* GPIO Clocks */
  62 #define IXP4XX_GPIO_CLK_0               14
  63 #define IXP4XX_GPIO_CLK_1               15
  64
  65 static int ixp4xx_set_irq_type(struct irq_data *d, unsigned int type)
  66 {
  67         /* All are level active high (asserted) here */
  68         if (type != IRQ_TYPE_LEVEL_HIGH)
  69                 return -EINVAL;
  70         return 0;
  71 }
  72
  73 static void ixp4xx_irq_mask(struct irq_data *d)
  74 {
  75         struct ixp4xx_irq *ixi = irq_data_get_irq_chip_data(d);
  76         u32 val;
  77
  78         if (ixi->is_356 && d->hwirq >= 32) {
  79                 val = __raw_readl(ixi->irqbase + IXP4XX_ICMR2);
  80                 val &= ~BIT(d->hwirq - 32);
  81                 __raw_writel(val, ixi->irqbase + IXP4XX_ICMR2);
  82         } else {
  83                 val = __raw_readl(ixi->irqbase + IXP4XX_ICMR);
  84                 val &= ~BIT(d->hwirq);
  85                 __raw_writel(val, ixi->irqbase + IXP4XX_ICMR);
  86         }
  87 }
  88
  89 /*
  90  * Level triggered interrupts on GPIO lines can only be cleared when the
  91  * interrupt condition disappears.
  92  */
  93 static void ixp4xx_irq_unmask(struct irq_data *d)
  94 {
  95         struct ixp4xx_irq *ixi = irq_data_get_irq_chip_data(d);
  96         u32 val;
  97
  98         if (ixi->is_356 && d->hwirq >= 32) {
  99                 val = __raw_readl(ixi->irqbase + IXP4XX_ICMR2);
 100                 val |= BIT(d->hwirq - 32);
 101                 __raw_writel(val, ixi->irqbase + IXP4XX_ICMR2);
 102         } else {
 103                 val = __raw_readl(ixi->irqbase + IXP4XX_ICMR);
 104                 val |= BIT(d->hwirq);
 105                 __raw_writel(val, ixi->irqbase + IXP4XX_ICMR);
 106         }
 107 }
 108
 109 asmlinkage void __exception_irq_entry ixp4xx_handle_irq(struct pt_regs *regs)
 110 {
 111         struct ixp4xx_irq *ixi = &ixirq;
 112         unsigned long status;
 113         int i;
 114
 115         status = __raw_readl(ixi->irqbase + IXP4XX_ICIP);
 116         for_each_set_bit(i, &status, 32)
 117                 handle_domain_irq(ixi->domain, i, regs);
 118
 119         /*
 120          * IXP465/IXP435 has an upper IRQ status register
 121          */
 122         if (ixi->is_356) {
 123                 status = __raw_readl(ixi->irqbase + IXP4XX_ICIP2);
 124                 for_each_set_bit(i, &status, 32)
 125                         handle_domain_irq(ixi->domain, i + 32, regs);
 126         }
 127 }
 128
 129 static int ixp4xx_irq_domain_translate(struct irq_domain *domain,
 130                                        struct irq_fwspec *fwspec,
 131                                        unsigned long *hwirq,
 132                                        unsigned int *type)
 133 {
 134         /* We support standard DT translation */
 135         if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
 136                 *hwirq = fwspec->param[0];
 137                 *type = fwspec->param[1];
 138                 return 0;
 139         }
 140
 141         if (is_fwnode_irqchip(fwspec->fwnode)) {
 142                 if (fwspec->param_count != 2)
 143                         return -EINVAL;
 144                 *hwirq = fwspec->param[0];
 145                 *type = fwspec->param[1];
 146                 WARN_ON(*type == IRQ_TYPE_NONE);
 147                 return 0;
 148         }
 149
 150         return -EINVAL;
 151 }
 152
 153 static int ixp4xx_irq_domain_alloc(struct irq_domain *d,
 154                                    unsigned int irq, unsigned int nr_irqs,
 155                                    void *data)
 156 {
 157         struct ixp4xx_irq *ixi = d->host_data;
 158         irq_hw_number_t hwirq;
 159         unsigned int type = IRQ_TYPE_NONE;
 160         struct irq_fwspec *fwspec = data;
 161         int ret;
 162         int i;
 163
 164         ret = ixp4xx_irq_domain_translate(d, fwspec, &hwirq, &type);
 165         if (ret)
 166                 return ret;
 167
 168         for (i = 0; i < nr_irqs; i++) {
 169                 /*
 170                  * TODO: after converting IXP4xx to only device tree, set
 171                  * handle_bad_irq as default handler and assume all consumers
 172                  * call .set_type() as this is provided in the second cell in
 173                  * the device tree phandle.
 174                  */
 175                 irq_domain_set_info(d,
 176                                     irq + i,
 177                                     hwirq + i,
 178                                     &ixi->irqchip,
 179                                     ixi,
 180                                     handle_level_irq,
 181                                     NULL, NULL);
 182                 irq_set_probe(irq + i);
 183         }
 184
 185         return 0;
 186 }
 187
 188 /*
 189  * This needs to be a hierarchical irqdomain to work well with the
 190  * GPIO irqchip (which is lower in the hierarchy)
 191  */
 192 static const struct irq_domain_ops ixp4xx_irqdomain_ops = {
 193         .translate = ixp4xx_irq_domain_translate,
 194         .alloc = ixp4xx_irq_domain_alloc,
 195         .free = irq_domain_free_irqs_common,
 196 };
 197
 198 /**
 199  * ixp4xx_get_irq_domain() - retrieve the ixp4xx irq domain
 200  *
 201  * This function will go away when we transition to DT probing.
 202  */
 203 struct irq_domain *ixp4xx_get_irq_domain(void)
 204 {
 205         struct ixp4xx_irq *ixi = &ixirq;
 206
 207         return ixi->domain;
 208 }
 209 EXPORT_SYMBOL_GPL(ixp4xx_get_irq_domain);
 210
 211 /*
 212  * This is the Linux IRQ to hwirq mapping table. This goes away when
 213  * we have DT support as all IRQ resources are defined in the device
 214  * tree. It will register all the IRQs that are not used by the hierarchical
 215  * GPIO IRQ chip. The "holes" inbetween these IRQs will be requested by
 216  * the GPIO driver using . This is a step-gap solution.
 217  */
 218 struct ixp4xx_irq_chunk {
 219         int irq;
 220         int hwirq;
 221         int nr_irqs;
 222 };
 223
 224 static const struct ixp4xx_irq_chunk ixp4xx_irq_chunks[] = {
 225         {
 226                 .irq = 16,
 227                 .hwirq = 0,
 228                 .nr_irqs = 6,
 229         },
 230         {
 231                 .irq = 24,
 232                 .hwirq = 8,
 233                 .nr_irqs = 11,
 234         },
 235         {
 236                 .irq = 46,
 237                 .hwirq = 30,
 238                 .nr_irqs = 2,
 239         },
 240         /* Only on the 436 variants */
 241         {
 242                 .irq = 48,
 243                 .hwirq = 32,
 244                 .nr_irqs = 10,
 245         },
 246 };
 247
 248 /**
 249  * ixp4x_irq_setup() - Common setup code for the IXP4xx interrupt controller
 250  * @ixi: State container
 251  * @irqbase: Virtual memory base for the interrupt controller
 252  * @fwnode: Corresponding fwnode abstraction for this controller
 253  * @is_356: if this is an IXP43x, IXP45x or IXP46x SoC variant
 254  */
 255 static int __init ixp4xx_irq_setup(struct ixp4xx_irq *ixi,
 256                                    void __iomem *irqbase,
 257                                    struct fwnode_handle *fwnode,
 258                                    bool is_356)
 259 {
 260         int nr_irqs;
 261
 262         ixi->irqbase = irqbase;
 263         ixi->is_356 = is_356;
 264
 265         /* Route all sources to IRQ instead of FIQ */
 266         __raw_writel(0x0, ixi->irqbase + IXP4XX_ICLR);
 267
 268         /* Disable all interrupts */
 269         __raw_writel(0x0, ixi->irqbase + IXP4XX_ICMR);
 270
 271         if (is_356) {
 272                 /* Route upper 32 sources to IRQ instead of FIQ */
 273                 __raw_writel(0x0, ixi->irqbase + IXP4XX_ICLR2);
 274
 275                 /* Disable upper 32 interrupts */
 276                 __raw_writel(0x0, ixi->irqbase + IXP4XX_ICMR2);
 277
 278                 nr_irqs = 64;
 279         } else {
 280                 nr_irqs = 32;
 281         }
 282
 283         ixi->irqchip.name = "IXP4xx";
 284         ixi->irqchip.irq_mask = ixp4xx_irq_mask;
 285         ixi->irqchip.irq_unmask = ixp4xx_irq_unmask;
 286         ixi->irqchip.irq_set_type = ixp4xx_set_irq_type;
 287
 288         ixi->domain = irq_domain_create_linear(fwnode, nr_irqs,
 289                                                &ixp4xx_irqdomain_ops,
 290                                                ixi);
 291         if (!ixi->domain) {
 292                 pr_crit("IXP4XX: can not add primary irqdomain\n");
 293                 return -ENODEV;
 294         }
 295
 296         set_handle_irq(ixp4xx_handle_irq);
 297
 298         return 0;
 299 }
 300
 301 /**
 302  * ixp4xx_irq_init() - Function to initialize the irqchip from boardfiles
 303  * @irqbase: physical base for the irq controller
 304  * @is_356: if this is an IXP43x, IXP45x or IXP46x SoC variant
 305  */
 306 void __init ixp4xx_irq_init(resource_size_t irqbase,
 307                             bool is_356)
 308 {
 309         struct ixp4xx_irq *ixi = &ixirq;
 310         void __iomem *base;
 311         struct fwnode_handle *fwnode;
 312         struct irq_fwspec fwspec;
 313         int nr_chunks;
 314         int ret;
 315         int i;
 316
 317         base = ioremap(irqbase, 0x100);
 318         if (!base) {
 319                 pr_crit("IXP4XX: could not ioremap interrupt controller\n");
 320                 return;
 321         }
 322         fwnode = irq_domain_alloc_fwnode(&irqbase);
 323         if (!fwnode) {
 324                 pr_crit("IXP4XX: no domain handle\n");
 325                 return;
 326         }
 327         ret = ixp4xx_irq_setup(ixi, base, fwnode, is_356);
 328         if (ret) {
 329                 pr_crit("IXP4XX: failed to set up irqchip\n");
 330                 irq_domain_free_fwnode(fwnode);
 331         }
 332
 333         nr_chunks = ARRAY_SIZE(ixp4xx_irq_chunks);
 334         if (!is_356)
 335                 nr_chunks--;
 336
 337         /*
 338          * After adding OF support, this is no longer needed: irqs
 339          * will be allocated for the respective fwnodes.
 340          */
 341         for (i = 0; i < nr_chunks; i++) {
 342                 const struct ixp4xx_irq_chunk *chunk = &ixp4xx_irq_chunks[i];
 343
 344                 pr_info("Allocate Linux IRQs %d..%d HW IRQs %d..%d\n",
 345                         chunk->irq, chunk->irq + chunk->nr_irqs - 1,
 346                         chunk->hwirq, chunk->hwirq + chunk->nr_irqs - 1);
 347                 fwspec.fwnode = fwnode;
 348                 fwspec.param[0] = chunk->hwirq;
 349                 fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
 350                 fwspec.param_count = 2;
 351                 ret = __irq_domain_alloc_irqs(ixi->domain,
 352                                               chunk->irq,
 353                                               chunk->nr_irqs,
 354                                               NUMA_NO_NODE,
 355                                               &fwspec,
 356                                               false,
 357                                               NULL);
 358                 if (ret < 0) {
 359                         pr_crit("IXP4XX: can not allocate irqs in hierarchy %d\n",
 360                                 ret);
 361                         return;
 362                 }
 363         }
 364 }
 365 EXPORT_SYMBOL_GPL(ixp4xx_irq_init);
 366
 367 #ifdef CONFIG_OF
 368 int __init ixp4xx_of_init_irq(struct device_node *np,
 369                               struct device_node *parent)
 370 {
 371         struct ixp4xx_irq *ixi = &ixirq;
 372         void __iomem *base;
 373         struct fwnode_handle *fwnode;
 374         bool is_356;
 375         int ret;
 376
 377         base = of_iomap(np, 0);
 378         if (!base) {
 379                 pr_crit("IXP4XX: could not ioremap interrupt controller\n");
 380                 return -ENODEV;
 381         }
 382         fwnode = of_node_to_fwnode(np);
 383
 384         /* These chip variants have 64 interrupts */
 385         is_356 = of_device_is_compatible(np, "intel,ixp43x-interrupt") ||
 386                 of_device_is_compatible(np, "intel,ixp45x-interrupt") ||
 387                 of_device_is_compatible(np, "intel,ixp46x-interrupt");
 388
 389         ret = ixp4xx_irq_setup(ixi, base, fwnode, is_356);
 390         if (ret)
 391                 pr_crit("IXP4XX: failed to set up irqchip\n");
 392
 393         return ret;
 394 }
 395 IRQCHIP_DECLARE(ixp42x, "intel,ixp42x-interrupt",
 396                 ixp4xx_of_init_irq);
 397 IRQCHIP_DECLARE(ixp43x, "intel,ixp43x-interrupt",
 398                 ixp4xx_of_init_irq);
 399 IRQCHIP_DECLARE(ixp45x, "intel,ixp45x-interrupt",
 400                 ixp4xx_of_init_irq);
 401 IRQCHIP_DECLARE(ixp46x, "intel,ixp46x-interrupt",
 402                 ixp4xx_of_init_irq);
 403 #endif