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