drivers/irqchip/irq-qcom-mpm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2021, Linaro Limited
   4  * Copyright (c) 2010-2020, The Linux Foundation. All rights reserved.
   5  */
   6
   7 #include <linux/delay.h>
   8 #include <linux/err.h>
   9 #include <linux/init.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/io.h>
  12 #include <linux/irqchip.h>
  13 #include <linux/irqdomain.h>
  14 #include <linux/mailbox_client.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pm_domain.h>
  21 #include <linux/slab.h>
  22 #include <linux/soc/qcom/irq.h>
  23 #include <linux/spinlock.h>
  24
  25 /*
  26  * This is the driver for Qualcomm MPM (MSM Power Manager) interrupt controller,
  27  * which is commonly found on Qualcomm SoCs built on the RPM architecture.
  28  * Sitting in always-on domain, MPM monitors the wakeup interrupts when SoC is
  29  * asleep, and wakes up the AP when one of those interrupts occurs.  This driver
  30  * doesn't directly access physical MPM registers though.  Instead, the access
  31  * is bridged via a piece of internal memory (SRAM) that is accessible to both
  32  * AP and RPM.  This piece of memory is called 'vMPM' in the driver.
  33  *
  34  * When SoC is awake, the vMPM is owned by AP and the register setup by this
  35  * driver all happens on vMPM.  When AP is about to get power collapsed, the
  36  * driver sends a mailbox notification to RPM, which will take over the vMPM
  37  * ownership and dump vMPM into physical MPM registers.  On wakeup, AP is woken
  38  * up by a MPM pin/interrupt, and RPM will copy STATUS registers into vMPM.
  39  * Then AP start owning vMPM again.
  40  *
  41  * vMPM register map:
  42  *
  43  *    31                              0
  44  *    +--------------------------------+
  45  *    |            TIMER0              | 0x00
  46  *    +--------------------------------+
  47  *    |            TIMER1              | 0x04
  48  *    +--------------------------------+
  49  *    |            ENABLE0             | 0x08
  50  *    +--------------------------------+
  51  *    |              ...               | ...
  52  *    +--------------------------------+
  53  *    |            ENABLEn             |
  54  *    +--------------------------------+
  55  *    |          FALLING_EDGE0         |
  56  *    +--------------------------------+
  57  *    |              ...               |
  58  *    +--------------------------------+
  59  *    |            STATUSn             |
  60  *    +--------------------------------+
  61  *
  62  *    n = DIV_ROUND_UP(pin_cnt, 32)
  63  *
  64  */
  65
  66 #define MPM_REG_ENABLE          0
  67 #define MPM_REG_FALLING_EDGE    1
  68 #define MPM_REG_RISING_EDGE     2
  69 #define MPM_REG_POLARITY        3
  70 #define MPM_REG_STATUS          4
  71
  72 /* MPM pin map to GIC hwirq */
  73 struct mpm_gic_map {
  74         int pin;
  75         irq_hw_number_t hwirq;
  76 };
  77
  78 struct qcom_mpm_priv {
  79         void __iomem *base;
  80         raw_spinlock_t lock;
  81         struct mbox_client mbox_client;
  82         struct mbox_chan *mbox_chan;
  83         struct mpm_gic_map *maps;
  84         unsigned int map_cnt;
  85         unsigned int reg_stride;
  86         struct irq_domain *domain;
  87         struct generic_pm_domain genpd;
  88 };
  89
  90 static u32 qcom_mpm_read(struct qcom_mpm_priv *priv, unsigned int reg,
  91                          unsigned int index)
  92 {
  93         unsigned int offset = (reg * priv->reg_stride + index + 2) * 4;
  94
  95         return readl_relaxed(priv->base + offset);
  96 }
  97
  98 static void qcom_mpm_write(struct qcom_mpm_priv *priv, unsigned int reg,
  99                            unsigned int index, u32 val)
 100 {
 101         unsigned int offset = (reg * priv->reg_stride + index + 2) * 4;
 102
 103         writel_relaxed(val, priv->base + offset);
 104
 105         /* Ensure the write is completed */
 106         wmb();
 107 }
 108
 109 static void qcom_mpm_enable_irq(struct irq_data *d, bool en)
 110 {
 111         struct qcom_mpm_priv *priv = d->chip_data;
 112         int pin = d->hwirq;
 113         unsigned int index = pin / 32;
 114         unsigned int shift = pin % 32;
 115         unsigned long flags, val;
 116
 117         raw_spin_lock_irqsave(&priv->lock, flags);
 118
 119         val = qcom_mpm_read(priv, MPM_REG_ENABLE, index);
 120         __assign_bit(shift, &val, en);
 121         qcom_mpm_write(priv, MPM_REG_ENABLE, index, val);
 122
 123         raw_spin_unlock_irqrestore(&priv->lock, flags);
 124 }
 125
 126 static void qcom_mpm_mask(struct irq_data *d)
 127 {
 128         qcom_mpm_enable_irq(d, false);
 129
 130         if (d->parent_data)
 131                 irq_chip_mask_parent(d);
 132 }
 133
 134 static void qcom_mpm_unmask(struct irq_data *d)
 135 {
 136         qcom_mpm_enable_irq(d, true);
 137
 138         if (d->parent_data)
 139                 irq_chip_unmask_parent(d);
 140 }
 141
 142 static void mpm_set_type(struct qcom_mpm_priv *priv, bool set, unsigned int reg,
 143                          unsigned int index, unsigned int shift)
 144 {
 145         unsigned long flags, val;
 146
 147         raw_spin_lock_irqsave(&priv->lock, flags);
 148
 149         val = qcom_mpm_read(priv, reg, index);
 150         __assign_bit(shift, &val, set);
 151         qcom_mpm_write(priv, reg, index, val);
 152
 153         raw_spin_unlock_irqrestore(&priv->lock, flags);
 154 }
 155
 156 static int qcom_mpm_set_type(struct irq_data *d, unsigned int type)
 157 {
 158         struct qcom_mpm_priv *priv = d->chip_data;
 159         int pin = d->hwirq;
 160         unsigned int index = pin / 32;
 161         unsigned int shift = pin % 32;
 162
 163         if (type & IRQ_TYPE_EDGE_RISING)
 164                 mpm_set_type(priv, true, MPM_REG_RISING_EDGE, index, shift);
 165         else
 166                 mpm_set_type(priv, false, MPM_REG_RISING_EDGE, index, shift);
 167
 168         if (type & IRQ_TYPE_EDGE_FALLING)
 169                 mpm_set_type(priv, true, MPM_REG_FALLING_EDGE, index, shift);
 170         else
 171                 mpm_set_type(priv, false, MPM_REG_FALLING_EDGE, index, shift);
 172
 173         if (type & IRQ_TYPE_LEVEL_HIGH)
 174                 mpm_set_type(priv, true, MPM_REG_POLARITY, index, shift);
 175         else
 176                 mpm_set_type(priv, false, MPM_REG_POLARITY, index, shift);
 177
 178         if (!d->parent_data)
 179                 return 0;
 180
 181         if (type & IRQ_TYPE_EDGE_BOTH)
 182                 type = IRQ_TYPE_EDGE_RISING;
 183
 184         if (type & IRQ_TYPE_LEVEL_MASK)
 185                 type = IRQ_TYPE_LEVEL_HIGH;
 186
 187         return irq_chip_set_type_parent(d, type);
 188 }
 189
 190 static struct irq_chip qcom_mpm_chip = {
 191         .name                   = "mpm",
 192         .irq_eoi                = irq_chip_eoi_parent,
 193         .irq_mask               = qcom_mpm_mask,
 194         .irq_unmask             = qcom_mpm_unmask,
 195         .irq_retrigger          = irq_chip_retrigger_hierarchy,
 196         .irq_set_type           = qcom_mpm_set_type,
 197         .irq_set_affinity       = irq_chip_set_affinity_parent,
 198         .flags                  = IRQCHIP_MASK_ON_SUSPEND |
 199                                   IRQCHIP_SKIP_SET_WAKE,
 200 };
 201
 202 static struct mpm_gic_map *get_mpm_gic_map(struct qcom_mpm_priv *priv, int pin)
 203 {
 204         struct mpm_gic_map *maps = priv->maps;
 205         int i;
 206
 207         for (i = 0; i < priv->map_cnt; i++) {
 208                 if (maps[i].pin == pin)
 209                         return &maps[i];
 210         }
 211
 212         return NULL;
 213 }
 214
 215 static int qcom_mpm_alloc(struct irq_domain *domain, unsigned int virq,
 216                           unsigned int nr_irqs, void *data)
 217 {
 218         struct qcom_mpm_priv *priv = domain->host_data;
 219         struct irq_fwspec *fwspec = data;
 220         struct irq_fwspec parent_fwspec;
 221         struct mpm_gic_map *map;
 222         irq_hw_number_t pin;
 223         unsigned int type;
 224         int  ret;
 225
 226         ret = irq_domain_translate_twocell(domain, fwspec, &pin, &type);
 227         if (ret)
 228                 return ret;
 229
 230         ret = irq_domain_set_hwirq_and_chip(domain, virq, pin,
 231                                             &qcom_mpm_chip, priv);
 232         if (ret)
 233                 return ret;
 234
 235         map = get_mpm_gic_map(priv, pin);
 236         if (map == NULL)
 237                 return irq_domain_disconnect_hierarchy(domain->parent, virq);
 238
 239         if (type & IRQ_TYPE_EDGE_BOTH)
 240                 type = IRQ_TYPE_EDGE_RISING;
 241
 242         if (type & IRQ_TYPE_LEVEL_MASK)
 243                 type = IRQ_TYPE_LEVEL_HIGH;
 244
 245         parent_fwspec.fwnode = domain->parent->fwnode;
 246         parent_fwspec.param_count = 3;
 247         parent_fwspec.param[0] = 0;
 248         parent_fwspec.param[1] = map->hwirq;
 249         parent_fwspec.param[2] = type;
 250
 251         return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
 252                                             &parent_fwspec);
 253 }
 254
 255 static const struct irq_domain_ops qcom_mpm_ops = {
 256         .alloc          = qcom_mpm_alloc,
 257         .free           = irq_domain_free_irqs_common,
 258         .translate      = irq_domain_translate_twocell,
 259 };
 260
 261 /* Triggered by RPM when system resumes from deep sleep */
 262 static irqreturn_t qcom_mpm_handler(int irq, void *dev_id)
 263 {
 264         struct qcom_mpm_priv *priv = dev_id;
 265         unsigned long enable, pending;
 266         irqreturn_t ret = IRQ_NONE;
 267         unsigned long flags;
 268         int i, j;
 269
 270         for (i = 0; i < priv->reg_stride; i++) {
 271                 raw_spin_lock_irqsave(&priv->lock, flags);
 272                 enable = qcom_mpm_read(priv, MPM_REG_ENABLE, i);
 273                 pending = qcom_mpm_read(priv, MPM_REG_STATUS, i);
 274                 pending &= enable;
 275                 raw_spin_unlock_irqrestore(&priv->lock, flags);
 276
 277                 for_each_set_bit(j, &pending, 32) {
 278                         unsigned int pin = 32 * i + j;
 279                         struct irq_desc *desc = irq_resolve_mapping(priv->domain, pin);
 280                         struct irq_data *d = &desc->irq_data;
 281
 282                         if (!irqd_is_level_type(d))
 283                                 irq_set_irqchip_state(d->irq,
 284                                                 IRQCHIP_STATE_PENDING, true);
 285                         ret = IRQ_HANDLED;
 286                 }
 287         }
 288
 289         return ret;
 290 }
 291
 292 static int mpm_pd_power_off(struct generic_pm_domain *genpd)
 293 {
 294         struct qcom_mpm_priv *priv = container_of(genpd, struct qcom_mpm_priv,
 295                                                   genpd);
 296         int i, ret;
 297
 298         for (i = 0; i < priv->reg_stride; i++)
 299                 qcom_mpm_write(priv, MPM_REG_STATUS, i, 0);
 300
 301         /* Notify RPM to write vMPM into HW */
 302         ret = mbox_send_message(priv->mbox_chan, NULL);
 303         if (ret < 0)
 304                 return ret;
 305
 306         return 0;
 307 }
 308
 309 static bool gic_hwirq_is_mapped(struct mpm_gic_map *maps, int cnt, u32 hwirq)
 310 {
 311         int i;
 312
 313         for (i = 0; i < cnt; i++)
 314                 if (maps[i].hwirq == hwirq)
 315                         return true;
 316
 317         return false;
 318 }
 319
 320 static int qcom_mpm_init(struct device_node *np, struct device_node *parent)
 321 {
 322         struct platform_device *pdev = of_find_device_by_node(np);
 323         struct device *dev = &pdev->dev;
 324         struct irq_domain *parent_domain;
 325         struct generic_pm_domain *genpd;
 326         struct device_node *msgram_np;
 327         struct qcom_mpm_priv *priv;
 328         unsigned int pin_cnt;
 329         struct resource res;
 330         int i, irq;
 331         int ret;
 332
 333         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 334         if (!priv)
 335                 return -ENOMEM;
 336
 337         ret = of_property_read_u32(np, "qcom,mpm-pin-count", &pin_cnt);
 338         if (ret) {
 339                 dev_err(dev, "failed to read qcom,mpm-pin-count: %d\n", ret);
 340                 return ret;
 341         }
 342
 343         priv->reg_stride = DIV_ROUND_UP(pin_cnt, 32);
 344
 345         ret = of_property_count_u32_elems(np, "qcom,mpm-pin-map");
 346         if (ret < 0) {
 347                 dev_err(dev, "failed to read qcom,mpm-pin-map: %d\n", ret);
 348                 return ret;
 349         }
 350
 351         if (ret % 2) {
 352                 dev_err(dev, "invalid qcom,mpm-pin-map\n");
 353                 return -EINVAL;
 354         }
 355
 356         priv->map_cnt = ret / 2;
 357         priv->maps = devm_kcalloc(dev, priv->map_cnt, sizeof(*priv->maps),
 358                                   GFP_KERNEL);
 359         if (!priv->maps)
 360                 return -ENOMEM;
 361
 362         for (i = 0; i < priv->map_cnt; i++) {
 363                 u32 pin, hwirq;
 364
 365                 of_property_read_u32_index(np, "qcom,mpm-pin-map", i * 2, &pin);
 366                 of_property_read_u32_index(np, "qcom,mpm-pin-map", i * 2 + 1, &hwirq);
 367
 368                 if (gic_hwirq_is_mapped(priv->maps, i, hwirq)) {
 369                         dev_warn(dev, "failed to map pin %d as GIC hwirq %d is already mapped\n",
 370                                  pin, hwirq);
 371                         continue;
 372                 }
 373
 374                 priv->maps[i].pin = pin;
 375                 priv->maps[i].hwirq = hwirq;
 376         }
 377
 378         raw_spin_lock_init(&priv->lock);
 379
 380         /* If we have a handle to an RPM message ram partition, use it. */
 381         msgram_np = of_parse_phandle(np, "qcom,rpm-msg-ram", 0);
 382         if (msgram_np) {
 383                 ret = of_address_to_resource(msgram_np, 0, &res);
 384                 if (ret) {
 385                         of_node_put(msgram_np);
 386                         return ret;
 387                 }
 388
 389                 /* Don't use devm_ioremap_resource, as we're accessing a shared region. */
 390                 priv->base = devm_ioremap(dev, res.start, resource_size(&res));
 391                 of_node_put(msgram_np);
 392                 if (!priv->base)
 393                         return -ENOMEM;
 394         } else {
 395                 /* Otherwise, fall back to simple MMIO. */
 396                 priv->base = devm_platform_ioremap_resource(pdev, 0);
 397                 if (IS_ERR(priv->base))
 398                         return PTR_ERR(priv->base);
 399         }
 400
 401         for (i = 0; i < priv->reg_stride; i++) {
 402                 qcom_mpm_write(priv, MPM_REG_ENABLE, i, 0);
 403                 qcom_mpm_write(priv, MPM_REG_FALLING_EDGE, i, 0);
 404                 qcom_mpm_write(priv, MPM_REG_RISING_EDGE, i, 0);
 405                 qcom_mpm_write(priv, MPM_REG_POLARITY, i, 0);
 406                 qcom_mpm_write(priv, MPM_REG_STATUS, i, 0);
 407         }
 408
 409         irq = platform_get_irq(pdev, 0);
 410         if (irq < 0)
 411                 return irq;
 412
 413         genpd = &priv->genpd;
 414         genpd->flags = GENPD_FLAG_IRQ_SAFE;
 415         genpd->power_off = mpm_pd_power_off;
 416
 417         genpd->name = devm_kasprintf(dev, GFP_KERNEL, "%s", dev_name(dev));
 418         if (!genpd->name)
 419                 return -ENOMEM;
 420
 421         ret = pm_genpd_init(genpd, NULL, false);
 422         if (ret) {
 423                 dev_err(dev, "failed to init genpd: %d\n", ret);
 424                 return ret;
 425         }
 426
 427         ret = of_genpd_add_provider_simple(np, genpd);
 428         if (ret) {
 429                 dev_err(dev, "failed to add genpd provider: %d\n", ret);
 430                 goto remove_genpd;
 431         }
 432
 433         priv->mbox_client.dev = dev;
 434         priv->mbox_chan = mbox_request_channel(&priv->mbox_client, 0);
 435         if (IS_ERR(priv->mbox_chan)) {
 436                 ret = PTR_ERR(priv->mbox_chan);
 437                 dev_err(dev, "failed to acquire IPC channel: %d\n", ret);
 438                 return ret;
 439         }
 440
 441         parent_domain = irq_find_host(parent);
 442         if (!parent_domain) {
 443                 dev_err(dev, "failed to find MPM parent domain\n");
 444                 ret = -ENXIO;
 445                 goto free_mbox;
 446         }
 447
 448         priv->domain = irq_domain_create_hierarchy(parent_domain,
 449                                 IRQ_DOMAIN_FLAG_QCOM_MPM_WAKEUP, pin_cnt,
 450                                 of_node_to_fwnode(np), &qcom_mpm_ops, priv);
 451         if (!priv->domain) {
 452                 dev_err(dev, "failed to create MPM domain\n");
 453                 ret = -ENOMEM;
 454                 goto free_mbox;
 455         }
 456
 457         irq_domain_update_bus_token(priv->domain, DOMAIN_BUS_WAKEUP);
 458
 459         ret = devm_request_irq(dev, irq, qcom_mpm_handler, IRQF_NO_SUSPEND,
 460                                "qcom_mpm", priv);
 461         if (ret) {
 462                 dev_err(dev, "failed to request irq: %d\n", ret);
 463                 goto remove_domain;
 464         }
 465
 466         return 0;
 467
 468 remove_domain:
 469         irq_domain_remove(priv->domain);
 470 free_mbox:
 471         mbox_free_channel(priv->mbox_chan);
 472 remove_genpd:
 473         pm_genpd_remove(genpd);
 474         return ret;
 475 }
 476
 477 IRQCHIP_PLATFORM_DRIVER_BEGIN(qcom_mpm)
 478 IRQCHIP_MATCH("qcom,mpm", qcom_mpm_init)
 479 IRQCHIP_PLATFORM_DRIVER_END(qcom_mpm)
 480 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. MSM Power Manager");
 481 MODULE_LICENSE("GPL v2");