linux/drivers/irqchip/irq-meson-gpio.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2015 Endless Mobile, Inc.
   4 * Author: Carlo Caione <carlo@endlessm.com>
   5 * Copyright (c) 2016 BayLibre, SAS.
   6 * Author: Jerome Brunet <jbrunet@baylibre.com>
   7 */
   8
   9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11#include <linux/io.h>
  12#include <linux/module.h>
  13#include <linux/irq.h>
  14#include <linux/irqdomain.h>
  15#include <linux/irqchip.h>
  16#include <linux/of.h>
  17#include <linux/of_address.h>
  18
  19#define NUM_CHANNEL 8
  20#define MAX_INPUT_MUX 256
  21
  22#define REG_EDGE_POL    0x00
  23#define REG_PIN_03_SEL  0x04
  24#define REG_PIN_47_SEL  0x08
  25#define REG_FILTER_SEL  0x0c
  26
  27/* use for A1 like chips */
  28#define REG_PIN_A1_SEL  0x04
  29
  30/*
  31 * Note: The S905X3 datasheet reports that BOTH_EDGE is controlled by
  32 * bits 24 to 31. Tests on the actual HW show that these bits are
  33 * stuck at 0. Bits 8 to 15 are responsive and have the expected
  34 * effect.
  35 */
  36#define REG_EDGE_POL_EDGE(params, x)    BIT((params)->edge_single_offset + (x))
  37#define REG_EDGE_POL_LOW(params, x)     BIT((params)->pol_low_offset + (x))
  38#define REG_BOTH_EDGE(params, x)        BIT((params)->edge_both_offset + (x))
  39#define REG_EDGE_POL_MASK(params, x)    (       \
  40                REG_EDGE_POL_EDGE(params, x) |  \
  41                REG_EDGE_POL_LOW(params, x)  |  \
  42                REG_BOTH_EDGE(params, x))
  43#define REG_PIN_SEL_SHIFT(x)    (((x) % 4) * 8)
  44#define REG_FILTER_SEL_SHIFT(x) ((x) * 4)
  45
  46struct meson_gpio_irq_controller;
  47static void meson8_gpio_irq_sel_pin(struct meson_gpio_irq_controller *ctl,
  48                                    unsigned int channel, unsigned long hwirq);
  49static void meson_gpio_irq_init_dummy(struct meson_gpio_irq_controller *ctl);
  50static void meson_a1_gpio_irq_sel_pin(struct meson_gpio_irq_controller *ctl,
  51                                      unsigned int channel,
  52                                      unsigned long hwirq);
  53static void meson_a1_gpio_irq_init(struct meson_gpio_irq_controller *ctl);
  54
  55struct irq_ctl_ops {
  56        void (*gpio_irq_sel_pin)(struct meson_gpio_irq_controller *ctl,
  57                                 unsigned int channel, unsigned long hwirq);
  58        void (*gpio_irq_init)(struct meson_gpio_irq_controller *ctl);
  59};
  60
  61struct meson_gpio_irq_params {
  62        unsigned int nr_hwirq;
  63        bool support_edge_both;
  64        unsigned int edge_both_offset;
  65        unsigned int edge_single_offset;
  66        unsigned int pol_low_offset;
  67        unsigned int pin_sel_mask;
  68        struct irq_ctl_ops ops;
  69};
  70
  71#define INIT_MESON_COMMON(irqs, init, sel)                      \
  72        .nr_hwirq = irqs,                                       \
  73        .ops = {                                                \
  74                .gpio_irq_init = init,                          \
  75                .gpio_irq_sel_pin = sel,                        \
  76        },
  77
  78#define INIT_MESON8_COMMON_DATA(irqs)                           \
  79        INIT_MESON_COMMON(irqs, meson_gpio_irq_init_dummy,      \
  80                          meson8_gpio_irq_sel_pin)              \
  81        .edge_single_offset = 0,                                \
  82        .pol_low_offset = 16,                                   \
  83        .pin_sel_mask = 0xff,                                   \
  84
  85#define INIT_MESON_A1_COMMON_DATA(irqs)                         \
  86        INIT_MESON_COMMON(irqs, meson_a1_gpio_irq_init,         \
  87                          meson_a1_gpio_irq_sel_pin)            \
  88        .support_edge_both = true,                              \
  89        .edge_both_offset = 16,                                 \
  90        .edge_single_offset = 8,                                \
  91        .pol_low_offset = 0,                                    \
  92        .pin_sel_mask = 0x7f,                                   \
  93
  94static const struct meson_gpio_irq_params meson8_params = {
  95        INIT_MESON8_COMMON_DATA(134)
  96};
  97
  98static const struct meson_gpio_irq_params meson8b_params = {
  99        INIT_MESON8_COMMON_DATA(119)
 100};
 101
 102static const struct meson_gpio_irq_params gxbb_params = {
 103        INIT_MESON8_COMMON_DATA(133)
 104};
 105
 106static const struct meson_gpio_irq_params gxl_params = {
 107        INIT_MESON8_COMMON_DATA(110)
 108};
 109
 110static const struct meson_gpio_irq_params axg_params = {
 111        INIT_MESON8_COMMON_DATA(100)
 112};
 113
 114static const struct meson_gpio_irq_params sm1_params = {
 115        INIT_MESON8_COMMON_DATA(100)
 116        .support_edge_both = true,
 117        .edge_both_offset = 8,
 118};
 119
 120static const struct meson_gpio_irq_params a1_params = {
 121        INIT_MESON_A1_COMMON_DATA(62)
 122};
 123
 124static const struct of_device_id meson_irq_gpio_matches[] = {
 125        { .compatible = "amlogic,meson8-gpio-intc", .data = &meson8_params },
 126        { .compatible = "amlogic,meson8b-gpio-intc", .data = &meson8b_params },
 127        { .compatible = "amlogic,meson-gxbb-gpio-intc", .data = &gxbb_params },
 128        { .compatible = "amlogic,meson-gxl-gpio-intc", .data = &gxl_params },
 129        { .compatible = "amlogic,meson-axg-gpio-intc", .data = &axg_params },
 130        { .compatible = "amlogic,meson-g12a-gpio-intc", .data = &axg_params },
 131        { .compatible = "amlogic,meson-sm1-gpio-intc", .data = &sm1_params },
 132        { .compatible = "amlogic,meson-a1-gpio-intc", .data = &a1_params },
 133        { }
 134};
 135
 136struct meson_gpio_irq_controller {
 137        const struct meson_gpio_irq_params *params;
 138        void __iomem *base;
 139        u32 channel_irqs[NUM_CHANNEL];
 140        DECLARE_BITMAP(channel_map, NUM_CHANNEL);
 141        spinlock_t lock;
 142};
 143
 144static void meson_gpio_irq_update_bits(struct meson_gpio_irq_controller *ctl,
 145                                       unsigned int reg, u32 mask, u32 val)
 146{
 147        unsigned long flags;
 148        u32 tmp;
 149
 150        spin_lock_irqsave(&ctl->lock, flags);
 151
 152        tmp = readl_relaxed(ctl->base + reg);
 153        tmp &= ~mask;
 154        tmp |= val;
 155        writel_relaxed(tmp, ctl->base + reg);
 156
 157        spin_unlock_irqrestore(&ctl->lock, flags);
 158}
 159
 160static void meson_gpio_irq_init_dummy(struct meson_gpio_irq_controller *ctl)
 161{
 162}
 163
 164static void meson8_gpio_irq_sel_pin(struct meson_gpio_irq_controller *ctl,
 165                                    unsigned int channel, unsigned long hwirq)
 166{
 167        unsigned int reg_offset;
 168        unsigned int bit_offset;
 169
 170        reg_offset = (channel < 4) ? REG_PIN_03_SEL : REG_PIN_47_SEL;
 171        bit_offset = REG_PIN_SEL_SHIFT(channel);
 172
 173        meson_gpio_irq_update_bits(ctl, reg_offset,
 174                                   ctl->params->pin_sel_mask << bit_offset,
 175                                   hwirq << bit_offset);
 176}
 177
 178static void meson_a1_gpio_irq_sel_pin(struct meson_gpio_irq_controller *ctl,
 179                                      unsigned int channel,
 180                                      unsigned long hwirq)
 181{
 182        unsigned int reg_offset;
 183        unsigned int bit_offset;
 184
 185        bit_offset = ((channel % 2) == 0) ? 0 : 16;
 186        reg_offset = REG_PIN_A1_SEL + ((channel / 2) << 2);
 187
 188        meson_gpio_irq_update_bits(ctl, reg_offset,
 189                                   ctl->params->pin_sel_mask << bit_offset,
 190                                   hwirq << bit_offset);
 191}
 192
 193/* For a1 or later chips like a1 there is a switch to enable/disable irq */
 194static void meson_a1_gpio_irq_init(struct meson_gpio_irq_controller *ctl)
 195{
 196        meson_gpio_irq_update_bits(ctl, REG_EDGE_POL, BIT(31), BIT(31));
 197}
 198
 199static int
 200meson_gpio_irq_request_channel(struct meson_gpio_irq_controller *ctl,
 201                               unsigned long  hwirq,
 202                               u32 **channel_hwirq)
 203{
 204        unsigned long flags;
 205        unsigned int idx;
 206
 207        spin_lock_irqsave(&ctl->lock, flags);
 208
 209        /* Find a free channel */
 210        idx = find_first_zero_bit(ctl->channel_map, NUM_CHANNEL);
 211        if (idx >= NUM_CHANNEL) {
 212                spin_unlock_irqrestore(&ctl->lock, flags);
 213                pr_err("No channel available\n");
 214                return -ENOSPC;
 215        }
 216
 217        /* Mark the channel as used */
 218        set_bit(idx, ctl->channel_map);
 219
 220        spin_unlock_irqrestore(&ctl->lock, flags);
 221
 222        /*
 223         * Setup the mux of the channel to route the signal of the pad
 224         * to the appropriate input of the GIC
 225         */
 226        ctl->params->ops.gpio_irq_sel_pin(ctl, idx, hwirq);
 227
 228        /*
 229         * Get the hwirq number assigned to this channel through
 230         * a pointer the channel_irq table. The added benefit of this
 231         * method is that we can also retrieve the channel index with
 232         * it, using the table base.
 233         */
 234        *channel_hwirq = &(ctl->channel_irqs[idx]);
 235
 236        pr_debug("hwirq %lu assigned to channel %d - irq %u\n",
 237                 hwirq, idx, **channel_hwirq);
 238
 239        return 0;
 240}
 241
 242static unsigned int
 243meson_gpio_irq_get_channel_idx(struct meson_gpio_irq_controller *ctl,
 244                               u32 *channel_hwirq)
 245{
 246        return channel_hwirq - ctl->channel_irqs;
 247}
 248
 249static void
 250meson_gpio_irq_release_channel(struct meson_gpio_irq_controller *ctl,
 251                               u32 *channel_hwirq)
 252{
 253        unsigned int idx;
 254
 255        idx = meson_gpio_irq_get_channel_idx(ctl, channel_hwirq);
 256        clear_bit(idx, ctl->channel_map);
 257}
 258
 259static int meson_gpio_irq_type_setup(struct meson_gpio_irq_controller *ctl,
 260                                     unsigned int type,
 261                                     u32 *channel_hwirq)
 262{
 263        u32 val = 0;
 264        unsigned int idx;
 265        const struct meson_gpio_irq_params *params;
 266
 267        params = ctl->params;
 268        idx = meson_gpio_irq_get_channel_idx(ctl, channel_hwirq);
 269
 270        /*
 271         * The controller has a filter block to operate in either LEVEL or
 272         * EDGE mode, then signal is sent to the GIC. To enable LEVEL_LOW and
 273         * EDGE_FALLING support (which the GIC does not support), the filter
 274         * block is also able to invert the input signal it gets before
 275         * providing it to the GIC.
 276         */
 277        type &= IRQ_TYPE_SENSE_MASK;
 278
 279        /*
 280         * New controller support EDGE_BOTH trigger. This setting takes
 281         * precedence over the other edge/polarity settings
 282         */
 283        if (type == IRQ_TYPE_EDGE_BOTH) {
 284                if (!params->support_edge_both)
 285                        return -EINVAL;
 286
 287                val |= REG_BOTH_EDGE(params, idx);
 288        } else {
 289                if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))
 290                        val |= REG_EDGE_POL_EDGE(params, idx);
 291
 292                if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_EDGE_FALLING))
 293                        val |= REG_EDGE_POL_LOW(params, idx);
 294        }
 295
 296        meson_gpio_irq_update_bits(ctl, REG_EDGE_POL,
 297                                   REG_EDGE_POL_MASK(params, idx), val);
 298
 299        return 0;
 300}
 301
 302static unsigned int meson_gpio_irq_type_output(unsigned int type)
 303{
 304        unsigned int sense = type & IRQ_TYPE_SENSE_MASK;
 305
 306        type &= ~IRQ_TYPE_SENSE_MASK;
 307
 308        /*
 309         * The polarity of the signal provided to the GIC should always
 310         * be high.
 311         */
 312        if (sense & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 313                type |= IRQ_TYPE_LEVEL_HIGH;
 314        else
 315                type |= IRQ_TYPE_EDGE_RISING;
 316
 317        return type;
 318}
 319
 320static int meson_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 321{
 322        struct meson_gpio_irq_controller *ctl = data->domain->host_data;
 323        u32 *channel_hwirq = irq_data_get_irq_chip_data(data);
 324        int ret;
 325
 326        ret = meson_gpio_irq_type_setup(ctl, type, channel_hwirq);
 327        if (ret)
 328                return ret;
 329
 330        return irq_chip_set_type_parent(data,
 331                                        meson_gpio_irq_type_output(type));
 332}
 333
 334static struct irq_chip meson_gpio_irq_chip = {
 335        .name                   = "meson-gpio-irqchip",
 336        .irq_mask               = irq_chip_mask_parent,
 337        .irq_unmask             = irq_chip_unmask_parent,
 338        .irq_eoi                = irq_chip_eoi_parent,
 339        .irq_set_type           = meson_gpio_irq_set_type,
 340        .irq_retrigger          = irq_chip_retrigger_hierarchy,
 341#ifdef CONFIG_SMP
 342        .irq_set_affinity       = irq_chip_set_affinity_parent,
 343#endif
 344        .flags                  = IRQCHIP_SET_TYPE_MASKED,
 345};
 346
 347static int meson_gpio_irq_domain_translate(struct irq_domain *domain,
 348                                           struct irq_fwspec *fwspec,
 349                                           unsigned long *hwirq,
 350                                           unsigned int *type)
 351{
 352        if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
 353                *hwirq  = fwspec->param[0];
 354                *type   = fwspec->param[1];
 355                return 0;
 356        }
 357
 358        return -EINVAL;
 359}
 360
 361static int meson_gpio_irq_allocate_gic_irq(struct irq_domain *domain,
 362                                           unsigned int virq,
 363                                           u32 hwirq,
 364                                           unsigned int type)
 365{
 366        struct irq_fwspec fwspec;
 367
 368        fwspec.fwnode = domain->parent->fwnode;
 369        fwspec.param_count = 3;
 370        fwspec.param[0] = 0;    /* SPI */
 371        fwspec.param[1] = hwirq;
 372        fwspec.param[2] = meson_gpio_irq_type_output(type);
 373
 374        return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
 375}
 376
 377static int meson_gpio_irq_domain_alloc(struct irq_domain *domain,
 378                                       unsigned int virq,
 379                                       unsigned int nr_irqs,
 380                                       void *data)
 381{
 382        struct irq_fwspec *fwspec = data;
 383        struct meson_gpio_irq_controller *ctl = domain->host_data;
 384        unsigned long hwirq;
 385        u32 *channel_hwirq;
 386        unsigned int type;
 387        int ret;
 388
 389        if (WARN_ON(nr_irqs != 1))
 390                return -EINVAL;
 391
 392        ret = meson_gpio_irq_domain_translate(domain, fwspec, &hwirq, &type);
 393        if (ret)
 394                return ret;
 395
 396        ret = meson_gpio_irq_request_channel(ctl, hwirq, &channel_hwirq);
 397        if (ret)
 398                return ret;
 399
 400        ret = meson_gpio_irq_allocate_gic_irq(domain, virq,
 401                                              *channel_hwirq, type);
 402        if (ret < 0) {
 403                pr_err("failed to allocate gic irq %u\n", *channel_hwirq);
 404                meson_gpio_irq_release_channel(ctl, channel_hwirq);
 405                return ret;
 406        }
 407
 408        irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 409                                      &meson_gpio_irq_chip, channel_hwirq);
 410
 411        return 0;
 412}
 413
 414static void meson_gpio_irq_domain_free(struct irq_domain *domain,
 415                                       unsigned int virq,
 416                                       unsigned int nr_irqs)
 417{
 418        struct meson_gpio_irq_controller *ctl = domain->host_data;
 419        struct irq_data *irq_data;
 420        u32 *channel_hwirq;
 421
 422        if (WARN_ON(nr_irqs != 1))
 423                return;
 424
 425        irq_domain_free_irqs_parent(domain, virq, 1);
 426
 427        irq_data = irq_domain_get_irq_data(domain, virq);
 428        channel_hwirq = irq_data_get_irq_chip_data(irq_data);
 429
 430        meson_gpio_irq_release_channel(ctl, channel_hwirq);
 431}
 432
 433static const struct irq_domain_ops meson_gpio_irq_domain_ops = {
 434        .alloc          = meson_gpio_irq_domain_alloc,
 435        .free           = meson_gpio_irq_domain_free,
 436        .translate      = meson_gpio_irq_domain_translate,
 437};
 438
 439static int __init meson_gpio_irq_parse_dt(struct device_node *node,
 440                                          struct meson_gpio_irq_controller *ctl)
 441{
 442        const struct of_device_id *match;
 443        int ret;
 444
 445        match = of_match_node(meson_irq_gpio_matches, node);
 446        if (!match)
 447                return -ENODEV;
 448
 449        ctl->params = match->data;
 450
 451        ret = of_property_read_variable_u32_array(node,
 452                                                  "amlogic,channel-interrupts",
 453                                                  ctl->channel_irqs,
 454                                                  NUM_CHANNEL,
 455                                                  NUM_CHANNEL);
 456        if (ret < 0) {
 457                pr_err("can't get %d channel interrupts\n", NUM_CHANNEL);
 458                return ret;
 459        }
 460
 461        ctl->params->ops.gpio_irq_init(ctl);
 462
 463        return 0;
 464}
 465
 466static int __init meson_gpio_irq_of_init(struct device_node *node,
 467                                         struct device_node *parent)
 468{
 469        struct irq_domain *domain, *parent_domain;
 470        struct meson_gpio_irq_controller *ctl;
 471        int ret;
 472
 473        if (!parent) {
 474                pr_err("missing parent interrupt node\n");
 475                return -ENODEV;
 476        }
 477
 478        parent_domain = irq_find_host(parent);
 479        if (!parent_domain) {
 480                pr_err("unable to obtain parent domain\n");
 481                return -ENXIO;
 482        }
 483
 484        ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
 485        if (!ctl)
 486                return -ENOMEM;
 487
 488        spin_lock_init(&ctl->lock);
 489
 490        ctl->base = of_iomap(node, 0);
 491        if (!ctl->base) {
 492                ret = -ENOMEM;
 493                goto free_ctl;
 494        }
 495
 496        ret = meson_gpio_irq_parse_dt(node, ctl);
 497        if (ret)
 498                goto free_channel_irqs;
 499
 500        domain = irq_domain_create_hierarchy(parent_domain, 0,
 501                                             ctl->params->nr_hwirq,
 502                                             of_node_to_fwnode(node),
 503                                             &meson_gpio_irq_domain_ops,
 504                                             ctl);
 505        if (!domain) {
 506                pr_err("failed to add domain\n");
 507                ret = -ENODEV;
 508                goto free_channel_irqs;
 509        }
 510
 511        pr_info("%d to %d gpio interrupt mux initialized\n",
 512                ctl->params->nr_hwirq, NUM_CHANNEL);
 513
 514        return 0;
 515
 516free_channel_irqs:
 517        iounmap(ctl->base);
 518free_ctl:
 519        kfree(ctl);
 520
 521        return ret;
 522}
 523
 524IRQCHIP_DECLARE(meson_gpio_intc, "amlogic,meson-gpio-intc",
 525                meson_gpio_irq_of_init);
 526