linux/drivers/irqchip/irq-meson-gpio.c
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   1/*
   2 * Copyright (c) 2015 Endless Mobile, Inc.
   3 * Author: Carlo Caione <carlo@endlessm.com>
   4 * Copyright (c) 2016 BayLibre, SAS.
   5 * Author: Jerome Brunet <jbrunet@baylibre.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of version 2 of the GNU General Public License as
   9 * published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 * The full GNU General Public License is included in this distribution
  19 * in the file called COPYING.
  20 */
  21
  22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24#include <linux/io.h>
  25#include <linux/module.h>
  26#include <linux/irq.h>
  27#include <linux/irqdomain.h>
  28#include <linux/irqchip.h>
  29#include <linux/of.h>
  30#include <linux/of_address.h>
  31
  32#define NUM_CHANNEL 8
  33#define MAX_INPUT_MUX 256
  34
  35#define REG_EDGE_POL    0x00
  36#define REG_PIN_03_SEL  0x04
  37#define REG_PIN_47_SEL  0x08
  38#define REG_FILTER_SEL  0x0c
  39
  40#define REG_EDGE_POL_MASK(x)    (BIT(x) | BIT(16 + (x)))
  41#define REG_EDGE_POL_EDGE(x)    BIT(x)
  42#define REG_EDGE_POL_LOW(x)     BIT(16 + (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_params {
  47        unsigned int nr_hwirq;
  48};
  49
  50static const struct meson_gpio_irq_params meson8_params = {
  51        .nr_hwirq = 134,
  52};
  53
  54static const struct meson_gpio_irq_params meson8b_params = {
  55        .nr_hwirq = 119,
  56};
  57
  58static const struct meson_gpio_irq_params gxbb_params = {
  59        .nr_hwirq = 133,
  60};
  61
  62static const struct meson_gpio_irq_params gxl_params = {
  63        .nr_hwirq = 110,
  64};
  65
  66static const struct meson_gpio_irq_params axg_params = {
  67        .nr_hwirq = 100,
  68};
  69
  70static const struct of_device_id meson_irq_gpio_matches[] = {
  71        { .compatible = "amlogic,meson8-gpio-intc", .data = &meson8_params },
  72        { .compatible = "amlogic,meson8b-gpio-intc", .data = &meson8b_params },
  73        { .compatible = "amlogic,meson-gxbb-gpio-intc", .data = &gxbb_params },
  74        { .compatible = "amlogic,meson-gxl-gpio-intc", .data = &gxl_params },
  75        { .compatible = "amlogic,meson-axg-gpio-intc", .data = &axg_params },
  76        { }
  77};
  78
  79struct meson_gpio_irq_controller {
  80        unsigned int nr_hwirq;
  81        void __iomem *base;
  82        u32 channel_irqs[NUM_CHANNEL];
  83        DECLARE_BITMAP(channel_map, NUM_CHANNEL);
  84        spinlock_t lock;
  85};
  86
  87static void meson_gpio_irq_update_bits(struct meson_gpio_irq_controller *ctl,
  88                                       unsigned int reg, u32 mask, u32 val)
  89{
  90        u32 tmp;
  91
  92        tmp = readl_relaxed(ctl->base + reg);
  93        tmp &= ~mask;
  94        tmp |= val;
  95        writel_relaxed(tmp, ctl->base + reg);
  96}
  97
  98static unsigned int meson_gpio_irq_channel_to_reg(unsigned int channel)
  99{
 100        return (channel < 4) ? REG_PIN_03_SEL : REG_PIN_47_SEL;
 101}
 102
 103static int
 104meson_gpio_irq_request_channel(struct meson_gpio_irq_controller *ctl,
 105                               unsigned long  hwirq,
 106                               u32 **channel_hwirq)
 107{
 108        unsigned int reg, idx;
 109
 110        spin_lock(&ctl->lock);
 111
 112        /* Find a free channel */
 113        idx = find_first_zero_bit(ctl->channel_map, NUM_CHANNEL);
 114        if (idx >= NUM_CHANNEL) {
 115                spin_unlock(&ctl->lock);
 116                pr_err("No channel available\n");
 117                return -ENOSPC;
 118        }
 119
 120        /* Mark the channel as used */
 121        set_bit(idx, ctl->channel_map);
 122
 123        /*
 124         * Setup the mux of the channel to route the signal of the pad
 125         * to the appropriate input of the GIC
 126         */
 127        reg = meson_gpio_irq_channel_to_reg(idx);
 128        meson_gpio_irq_update_bits(ctl, reg,
 129                                   0xff << REG_PIN_SEL_SHIFT(idx),
 130                                   hwirq << REG_PIN_SEL_SHIFT(idx));
 131
 132        /*
 133         * Get the hwirq number assigned to this channel through
 134         * a pointer the channel_irq table. The added benifit of this
 135         * method is that we can also retrieve the channel index with
 136         * it, using the table base.
 137         */
 138        *channel_hwirq = &(ctl->channel_irqs[idx]);
 139
 140        spin_unlock(&ctl->lock);
 141
 142        pr_debug("hwirq %lu assigned to channel %d - irq %u\n",
 143                 hwirq, idx, **channel_hwirq);
 144
 145        return 0;
 146}
 147
 148static unsigned int
 149meson_gpio_irq_get_channel_idx(struct meson_gpio_irq_controller *ctl,
 150                               u32 *channel_hwirq)
 151{
 152        return channel_hwirq - ctl->channel_irqs;
 153}
 154
 155static void
 156meson_gpio_irq_release_channel(struct meson_gpio_irq_controller *ctl,
 157                               u32 *channel_hwirq)
 158{
 159        unsigned int idx;
 160
 161        idx = meson_gpio_irq_get_channel_idx(ctl, channel_hwirq);
 162        clear_bit(idx, ctl->channel_map);
 163}
 164
 165static int meson_gpio_irq_type_setup(struct meson_gpio_irq_controller *ctl,
 166                                     unsigned int type,
 167                                     u32 *channel_hwirq)
 168{
 169        u32 val = 0;
 170        unsigned int idx;
 171
 172        idx = meson_gpio_irq_get_channel_idx(ctl, channel_hwirq);
 173
 174        /*
 175         * The controller has a filter block to operate in either LEVEL or
 176         * EDGE mode, then signal is sent to the GIC. To enable LEVEL_LOW and
 177         * EDGE_FALLING support (which the GIC does not support), the filter
 178         * block is also able to invert the input signal it gets before
 179         * providing it to the GIC.
 180         */
 181        type &= IRQ_TYPE_SENSE_MASK;
 182
 183        if (type == IRQ_TYPE_EDGE_BOTH)
 184                return -EINVAL;
 185
 186        if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))
 187                val |= REG_EDGE_POL_EDGE(idx);
 188
 189        if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_EDGE_FALLING))
 190                val |= REG_EDGE_POL_LOW(idx);
 191
 192        spin_lock(&ctl->lock);
 193
 194        meson_gpio_irq_update_bits(ctl, REG_EDGE_POL,
 195                                   REG_EDGE_POL_MASK(idx), val);
 196
 197        spin_unlock(&ctl->lock);
 198
 199        return 0;
 200}
 201
 202static unsigned int meson_gpio_irq_type_output(unsigned int type)
 203{
 204        unsigned int sense = type & IRQ_TYPE_SENSE_MASK;
 205
 206        type &= ~IRQ_TYPE_SENSE_MASK;
 207
 208        /*
 209         * The polarity of the signal provided to the GIC should always
 210         * be high.
 211         */
 212        if (sense & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 213                type |= IRQ_TYPE_LEVEL_HIGH;
 214        else if (sense & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))
 215                type |= IRQ_TYPE_EDGE_RISING;
 216
 217        return type;
 218}
 219
 220static int meson_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 221{
 222        struct meson_gpio_irq_controller *ctl = data->domain->host_data;
 223        u32 *channel_hwirq = irq_data_get_irq_chip_data(data);
 224        int ret;
 225
 226        ret = meson_gpio_irq_type_setup(ctl, type, channel_hwirq);
 227        if (ret)
 228                return ret;
 229
 230        return irq_chip_set_type_parent(data,
 231                                        meson_gpio_irq_type_output(type));
 232}
 233
 234static struct irq_chip meson_gpio_irq_chip = {
 235        .name                   = "meson-gpio-irqchip",
 236        .irq_mask               = irq_chip_mask_parent,
 237        .irq_unmask             = irq_chip_unmask_parent,
 238        .irq_eoi                = irq_chip_eoi_parent,
 239        .irq_set_type           = meson_gpio_irq_set_type,
 240        .irq_retrigger          = irq_chip_retrigger_hierarchy,
 241#ifdef CONFIG_SMP
 242        .irq_set_affinity       = irq_chip_set_affinity_parent,
 243#endif
 244        .flags                  = IRQCHIP_SET_TYPE_MASKED,
 245};
 246
 247static int meson_gpio_irq_domain_translate(struct irq_domain *domain,
 248                                           struct irq_fwspec *fwspec,
 249                                           unsigned long *hwirq,
 250                                           unsigned int *type)
 251{
 252        if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
 253                *hwirq  = fwspec->param[0];
 254                *type   = fwspec->param[1];
 255                return 0;
 256        }
 257
 258        return -EINVAL;
 259}
 260
 261static int meson_gpio_irq_allocate_gic_irq(struct irq_domain *domain,
 262                                           unsigned int virq,
 263                                           u32 hwirq,
 264                                           unsigned int type)
 265{
 266        struct irq_fwspec fwspec;
 267
 268        fwspec.fwnode = domain->parent->fwnode;
 269        fwspec.param_count = 3;
 270        fwspec.param[0] = 0;    /* SPI */
 271        fwspec.param[1] = hwirq;
 272        fwspec.param[2] = meson_gpio_irq_type_output(type);
 273
 274        return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
 275}
 276
 277static int meson_gpio_irq_domain_alloc(struct irq_domain *domain,
 278                                       unsigned int virq,
 279                                       unsigned int nr_irqs,
 280                                       void *data)
 281{
 282        struct irq_fwspec *fwspec = data;
 283        struct meson_gpio_irq_controller *ctl = domain->host_data;
 284        unsigned long hwirq;
 285        u32 *channel_hwirq;
 286        unsigned int type;
 287        int ret;
 288
 289        if (WARN_ON(nr_irqs != 1))
 290                return -EINVAL;
 291
 292        ret = meson_gpio_irq_domain_translate(domain, fwspec, &hwirq, &type);
 293        if (ret)
 294                return ret;
 295
 296        ret = meson_gpio_irq_request_channel(ctl, hwirq, &channel_hwirq);
 297        if (ret)
 298                return ret;
 299
 300        ret = meson_gpio_irq_allocate_gic_irq(domain, virq,
 301                                              *channel_hwirq, type);
 302        if (ret < 0) {
 303                pr_err("failed to allocate gic irq %u\n", *channel_hwirq);
 304                meson_gpio_irq_release_channel(ctl, channel_hwirq);
 305                return ret;
 306        }
 307
 308        irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 309                                      &meson_gpio_irq_chip, channel_hwirq);
 310
 311        return 0;
 312}
 313
 314static void meson_gpio_irq_domain_free(struct irq_domain *domain,
 315                                       unsigned int virq,
 316                                       unsigned int nr_irqs)
 317{
 318        struct meson_gpio_irq_controller *ctl = domain->host_data;
 319        struct irq_data *irq_data;
 320        u32 *channel_hwirq;
 321
 322        if (WARN_ON(nr_irqs != 1))
 323                return;
 324
 325        irq_domain_free_irqs_parent(domain, virq, 1);
 326
 327        irq_data = irq_domain_get_irq_data(domain, virq);
 328        channel_hwirq = irq_data_get_irq_chip_data(irq_data);
 329
 330        meson_gpio_irq_release_channel(ctl, channel_hwirq);
 331}
 332
 333static const struct irq_domain_ops meson_gpio_irq_domain_ops = {
 334        .alloc          = meson_gpio_irq_domain_alloc,
 335        .free           = meson_gpio_irq_domain_free,
 336        .translate      = meson_gpio_irq_domain_translate,
 337};
 338
 339static int __init meson_gpio_irq_parse_dt(struct device_node *node,
 340                                          struct meson_gpio_irq_controller *ctl)
 341{
 342        const struct of_device_id *match;
 343        const struct meson_gpio_irq_params *params;
 344        int ret;
 345
 346        match = of_match_node(meson_irq_gpio_matches, node);
 347        if (!match)
 348                return -ENODEV;
 349
 350        params = match->data;
 351        ctl->nr_hwirq = params->nr_hwirq;
 352
 353        ret = of_property_read_variable_u32_array(node,
 354                                                  "amlogic,channel-interrupts",
 355                                                  ctl->channel_irqs,
 356                                                  NUM_CHANNEL,
 357                                                  NUM_CHANNEL);
 358        if (ret < 0) {
 359                pr_err("can't get %d channel interrupts\n", NUM_CHANNEL);
 360                return ret;
 361        }
 362
 363        return 0;
 364}
 365
 366static int __init meson_gpio_irq_of_init(struct device_node *node,
 367                                         struct device_node *parent)
 368{
 369        struct irq_domain *domain, *parent_domain;
 370        struct meson_gpio_irq_controller *ctl;
 371        int ret;
 372
 373        if (!parent) {
 374                pr_err("missing parent interrupt node\n");
 375                return -ENODEV;
 376        }
 377
 378        parent_domain = irq_find_host(parent);
 379        if (!parent_domain) {
 380                pr_err("unable to obtain parent domain\n");
 381                return -ENXIO;
 382        }
 383
 384        ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
 385        if (!ctl)
 386                return -ENOMEM;
 387
 388        spin_lock_init(&ctl->lock);
 389
 390        ctl->base = of_iomap(node, 0);
 391        if (!ctl->base) {
 392                ret = -ENOMEM;
 393                goto free_ctl;
 394        }
 395
 396        ret = meson_gpio_irq_parse_dt(node, ctl);
 397        if (ret)
 398                goto free_channel_irqs;
 399
 400        domain = irq_domain_create_hierarchy(parent_domain, 0, ctl->nr_hwirq,
 401                                             of_node_to_fwnode(node),
 402                                             &meson_gpio_irq_domain_ops,
 403                                             ctl);
 404        if (!domain) {
 405                pr_err("failed to add domain\n");
 406                ret = -ENODEV;
 407                goto free_channel_irqs;
 408        }
 409
 410        pr_info("%d to %d gpio interrupt mux initialized\n",
 411                ctl->nr_hwirq, NUM_CHANNEL);
 412
 413        return 0;
 414
 415free_channel_irqs:
 416        iounmap(ctl->base);
 417free_ctl:
 418        kfree(ctl);
 419
 420        return ret;
 421}
 422
 423IRQCHIP_DECLARE(meson_gpio_intc, "amlogic,meson-gpio-intc",
 424                meson_gpio_irq_of_init);
 425