drivers/hsi/controllers/omap_ssi_core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* OMAP SSI driver.
   3  *
   4  * Copyright (C) 2010 Nokia Corporation. All rights reserved.
   5  * Copyright (C) 2014 Sebastian Reichel <sre@kernel.org>
   6  *
   7  * Contact: Carlos Chinea <carlos.chinea@nokia.com>
   8  */
   9
  10 #include <linux/compiler.h>
  11 #include <linux/err.h>
  12 #include <linux/ioport.h>
  13 #include <linux/io.h>
  14 #include <linux/clk.h>
  15 #include <linux/device.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/dma-mapping.h>
  18 #include <linux/dmaengine.h>
  19 #include <linux/delay.h>
  20 #include <linux/hsi/ssi_protocol.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/scatterlist.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/debugfs.h>
  26 #include <linux/pinctrl/consumer.h>
  27 #include <linux/pm_runtime.h>
  28 #include <linux/of.h>
  29 #include <linux/of_platform.h>
  30 #include <linux/hsi/hsi.h>
  31 #include <linux/idr.h>
  32
  33 #include "omap_ssi_regs.h"
  34 #include "omap_ssi.h"
  35
  36 /* For automatically allocated device IDs */
  37 static DEFINE_IDA(platform_omap_ssi_ida);
  38
  39 #ifdef CONFIG_DEBUG_FS
  40 static int ssi_regs_show(struct seq_file *m, void *p __maybe_unused)
  41 {
  42         struct hsi_controller *ssi = m->private;
  43         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  44         void __iomem *sys = omap_ssi->sys;
  45
  46         pm_runtime_get_sync(ssi->device.parent);
  47         seq_printf(m, "REVISION\t: 0x%08x\n",  readl(sys + SSI_REVISION_REG));
  48         seq_printf(m, "SYSCONFIG\t: 0x%08x\n", readl(sys + SSI_SYSCONFIG_REG));
  49         seq_printf(m, "SYSSTATUS\t: 0x%08x\n", readl(sys + SSI_SYSSTATUS_REG));
  50         pm_runtime_put(ssi->device.parent);
  51
  52         return 0;
  53 }
  54
  55 static int ssi_gdd_regs_show(struct seq_file *m, void *p __maybe_unused)
  56 {
  57         struct hsi_controller *ssi = m->private;
  58         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  59         void __iomem *gdd = omap_ssi->gdd;
  60         void __iomem *sys = omap_ssi->sys;
  61         int lch;
  62
  63         pm_runtime_get_sync(ssi->device.parent);
  64
  65         seq_printf(m, "GDD_MPU_STATUS\t: 0x%08x\n",
  66                 readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG));
  67         seq_printf(m, "GDD_MPU_ENABLE\t: 0x%08x\n\n",
  68                 readl(sys + SSI_GDD_MPU_IRQ_ENABLE_REG));
  69         seq_printf(m, "HW_ID\t\t: 0x%08x\n",
  70                                 readl(gdd + SSI_GDD_HW_ID_REG));
  71         seq_printf(m, "PPORT_ID\t: 0x%08x\n",
  72                                 readl(gdd + SSI_GDD_PPORT_ID_REG));
  73         seq_printf(m, "MPORT_ID\t: 0x%08x\n",
  74                                 readl(gdd + SSI_GDD_MPORT_ID_REG));
  75         seq_printf(m, "TEST\t\t: 0x%08x\n",
  76                                 readl(gdd + SSI_GDD_TEST_REG));
  77         seq_printf(m, "GCR\t\t: 0x%08x\n",
  78                                 readl(gdd + SSI_GDD_GCR_REG));
  79
  80         for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) {
  81                 seq_printf(m, "\nGDD LCH %d\n=========\n", lch);
  82                 seq_printf(m, "CSDP\t\t: 0x%04x\n",
  83                                 readw(gdd + SSI_GDD_CSDP_REG(lch)));
  84                 seq_printf(m, "CCR\t\t: 0x%04x\n",
  85                                 readw(gdd + SSI_GDD_CCR_REG(lch)));
  86                 seq_printf(m, "CICR\t\t: 0x%04x\n",
  87                                 readw(gdd + SSI_GDD_CICR_REG(lch)));
  88                 seq_printf(m, "CSR\t\t: 0x%04x\n",
  89                                 readw(gdd + SSI_GDD_CSR_REG(lch)));
  90                 seq_printf(m, "CSSA\t\t: 0x%08x\n",
  91                                 readl(gdd + SSI_GDD_CSSA_REG(lch)));
  92                 seq_printf(m, "CDSA\t\t: 0x%08x\n",
  93                                 readl(gdd + SSI_GDD_CDSA_REG(lch)));
  94                 seq_printf(m, "CEN\t\t: 0x%04x\n",
  95                                 readw(gdd + SSI_GDD_CEN_REG(lch)));
  96                 seq_printf(m, "CSAC\t\t: 0x%04x\n",
  97                                 readw(gdd + SSI_GDD_CSAC_REG(lch)));
  98                 seq_printf(m, "CDAC\t\t: 0x%04x\n",
  99                                 readw(gdd + SSI_GDD_CDAC_REG(lch)));
 100                 seq_printf(m, "CLNK_CTRL\t: 0x%04x\n",
 101                                 readw(gdd + SSI_GDD_CLNK_CTRL_REG(lch)));
 102         }
 103
 104         pm_runtime_put(ssi->device.parent);
 105
 106         return 0;
 107 }
 108
 109 DEFINE_SHOW_ATTRIBUTE(ssi_regs);
 110 DEFINE_SHOW_ATTRIBUTE(ssi_gdd_regs);
 111
 112 static int ssi_debug_add_ctrl(struct hsi_controller *ssi)
 113 {
 114         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 115         struct dentry *dir;
 116
 117         /* SSI controller */
 118         omap_ssi->dir = debugfs_create_dir(dev_name(&ssi->device), NULL);
 119         debugfs_create_file("regs", S_IRUGO, omap_ssi->dir, ssi, &ssi_regs_fops);
 120
 121         /* SSI GDD (DMA) */
 122         dir = debugfs_create_dir("gdd", omap_ssi->dir);
 123         debugfs_create_file("regs", S_IRUGO, dir, ssi, &ssi_gdd_regs_fops);
 124
 125         return 0;
 126 }
 127
 128 static void ssi_debug_remove_ctrl(struct hsi_controller *ssi)
 129 {
 130         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 131
 132         debugfs_remove_recursive(omap_ssi->dir);
 133 }
 134 #endif /* CONFIG_DEBUG_FS */
 135
 136 /*
 137  * FIXME: Horrible HACK needed until we remove the useless wakeline test
 138  * in the CMT. To be removed !!!!
 139  */
 140 void ssi_waketest(struct hsi_client *cl, unsigned int enable)
 141 {
 142         struct hsi_port *port = hsi_get_port(cl);
 143         struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
 144         struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
 145         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 146
 147         omap_port->wktest = !!enable;
 148         if (omap_port->wktest) {
 149                 pm_runtime_get_sync(ssi->device.parent);
 150                 writel_relaxed(SSI_WAKE(0),
 151                                 omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
 152         } else {
 153                 writel_relaxed(SSI_WAKE(0),
 154                                 omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
 155                 pm_runtime_put(ssi->device.parent);
 156         }
 157 }
 158 EXPORT_SYMBOL_GPL(ssi_waketest);
 159
 160 static void ssi_gdd_complete(struct hsi_controller *ssi, unsigned int lch)
 161 {
 162         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 163         struct hsi_msg *msg = omap_ssi->gdd_trn[lch].msg;
 164         struct hsi_port *port = to_hsi_port(msg->cl->device.parent);
 165         struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
 166         unsigned int dir;
 167         u32 csr;
 168         u32 val;
 169
 170         spin_lock(&omap_ssi->lock);
 171
 172         val = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
 173         val &= ~SSI_GDD_LCH(lch);
 174         writel_relaxed(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
 175
 176         if (msg->ttype == HSI_MSG_READ) {
 177                 dir = DMA_FROM_DEVICE;
 178                 val = SSI_DATAAVAILABLE(msg->channel);
 179                 pm_runtime_put(omap_port->pdev);
 180         } else {
 181                 dir = DMA_TO_DEVICE;
 182                 val = SSI_DATAACCEPT(msg->channel);
 183                 /* Keep clocks reference for write pio event */
 184         }
 185         dma_unmap_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents, dir);
 186         csr = readw(omap_ssi->gdd + SSI_GDD_CSR_REG(lch));
 187         omap_ssi->gdd_trn[lch].msg = NULL; /* release GDD lch */
 188         dev_dbg(&port->device, "DMA completed ch %d ttype %d\n",
 189                                 msg->channel, msg->ttype);
 190         spin_unlock(&omap_ssi->lock);
 191         if (csr & SSI_CSR_TOUR) { /* Timeout error */
 192                 msg->status = HSI_STATUS_ERROR;
 193                 msg->actual_len = 0;
 194                 spin_lock(&omap_port->lock);
 195                 list_del(&msg->link); /* Dequeue msg */
 196                 spin_unlock(&omap_port->lock);
 197
 198                 list_add_tail(&msg->link, &omap_port->errqueue);
 199                 schedule_delayed_work(&omap_port->errqueue_work, 0);
 200                 return;
 201         }
 202         spin_lock(&omap_port->lock);
 203         val |= readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
 204         writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
 205         spin_unlock(&omap_port->lock);
 206
 207         msg->status = HSI_STATUS_COMPLETED;
 208         msg->actual_len = sg_dma_len(msg->sgt.sgl);
 209 }
 210
 211 static void ssi_gdd_tasklet(unsigned long dev)
 212 {
 213         struct hsi_controller *ssi = (struct hsi_controller *)dev;
 214         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 215         void __iomem *sys = omap_ssi->sys;
 216         unsigned int lch;
 217         u32 status_reg;
 218
 219         pm_runtime_get(ssi->device.parent);
 220
 221         if (!pm_runtime_active(ssi->device.parent)) {
 222                 dev_warn(ssi->device.parent, "ssi_gdd_tasklet called without runtime PM!\n");
 223                 pm_runtime_put(ssi->device.parent);
 224                 return;
 225         }
 226
 227         status_reg = readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG);
 228         for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) {
 229                 if (status_reg & SSI_GDD_LCH(lch))
 230                         ssi_gdd_complete(ssi, lch);
 231         }
 232         writel_relaxed(status_reg, sys + SSI_GDD_MPU_IRQ_STATUS_REG);
 233         status_reg = readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG);
 234
 235         pm_runtime_put(ssi->device.parent);
 236
 237         if (status_reg)
 238                 tasklet_hi_schedule(&omap_ssi->gdd_tasklet);
 239         else
 240                 enable_irq(omap_ssi->gdd_irq);
 241
 242 }
 243
 244 static irqreturn_t ssi_gdd_isr(int irq, void *ssi)
 245 {
 246         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 247
 248         tasklet_hi_schedule(&omap_ssi->gdd_tasklet);
 249         disable_irq_nosync(irq);
 250
 251         return IRQ_HANDLED;
 252 }
 253
 254 static unsigned long ssi_get_clk_rate(struct hsi_controller *ssi)
 255 {
 256         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 257         unsigned long rate = clk_get_rate(omap_ssi->fck);
 258         return rate;
 259 }
 260
 261 static int ssi_clk_event(struct notifier_block *nb, unsigned long event,
 262                                                                 void *data)
 263 {
 264         struct omap_ssi_controller *omap_ssi = container_of(nb,
 265                                         struct omap_ssi_controller, fck_nb);
 266         struct hsi_controller *ssi = to_hsi_controller(omap_ssi->dev);
 267         struct clk_notifier_data *clk_data = data;
 268         struct omap_ssi_port *omap_port;
 269         int i;
 270
 271         switch (event) {
 272         case PRE_RATE_CHANGE:
 273                 dev_dbg(&ssi->device, "pre rate change\n");
 274
 275                 for (i = 0; i < ssi->num_ports; i++) {
 276                         omap_port = omap_ssi->port[i];
 277
 278                         if (!omap_port)
 279                                 continue;
 280
 281                         /* Workaround for SWBREAK + CAwake down race in CMT */
 282                         disable_irq(omap_port->wake_irq);
 283
 284                         /* stop all ssi communication */
 285                         pinctrl_pm_select_idle_state(omap_port->pdev);
 286                         udelay(1); /* wait for racing frames */
 287                 }
 288
 289                 break;
 290         case ABORT_RATE_CHANGE:
 291                 dev_dbg(&ssi->device, "abort rate change\n");
 292                 fallthrough;
 293         case POST_RATE_CHANGE:
 294                 dev_dbg(&ssi->device, "post rate change (%lu -> %lu)\n",
 295                         clk_data->old_rate, clk_data->new_rate);
 296                 omap_ssi->fck_rate = DIV_ROUND_CLOSEST(clk_data->new_rate, 1000); /* kHz */
 297
 298                 for (i = 0; i < ssi->num_ports; i++) {
 299                         omap_port = omap_ssi->port[i];
 300
 301                         if (!omap_port)
 302                                 continue;
 303
 304                         omap_ssi_port_update_fclk(ssi, omap_port);
 305
 306                         /* resume ssi communication */
 307                         pinctrl_pm_select_default_state(omap_port->pdev);
 308                         enable_irq(omap_port->wake_irq);
 309                 }
 310
 311                 break;
 312         default:
 313                 break;
 314         }
 315
 316         return NOTIFY_DONE;
 317 }
 318
 319 static int ssi_get_iomem(struct platform_device *pd,
 320                 const char *name, void __iomem **pbase, dma_addr_t *phy)
 321 {
 322         struct resource *mem;
 323         void __iomem *base;
 324         struct hsi_controller *ssi = platform_get_drvdata(pd);
 325
 326         mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name);
 327         base = devm_ioremap_resource(&ssi->device, mem);
 328         if (IS_ERR(base))
 329                 return PTR_ERR(base);
 330
 331         *pbase = base;
 332
 333         if (phy)
 334                 *phy = mem->start;
 335
 336         return 0;
 337 }
 338
 339 static int ssi_add_controller(struct hsi_controller *ssi,
 340                                                 struct platform_device *pd)
 341 {
 342         struct omap_ssi_controller *omap_ssi;
 343         int err;
 344
 345         omap_ssi = devm_kzalloc(&ssi->device, sizeof(*omap_ssi), GFP_KERNEL);
 346         if (!omap_ssi)
 347                 return -ENOMEM;
 348
 349         err = ida_alloc(&platform_omap_ssi_ida, GFP_KERNEL);
 350         if (err < 0)
 351                 return err;
 352         ssi->id = err;
 353
 354         ssi->owner = THIS_MODULE;
 355         ssi->device.parent = &pd->dev;
 356         dev_set_name(&ssi->device, "ssi%d", ssi->id);
 357         hsi_controller_set_drvdata(ssi, omap_ssi);
 358         omap_ssi->dev = &ssi->device;
 359         err = ssi_get_iomem(pd, "sys", &omap_ssi->sys, NULL);
 360         if (err < 0)
 361                 goto out_err;
 362         err = ssi_get_iomem(pd, "gdd", &omap_ssi->gdd, NULL);
 363         if (err < 0)
 364                 goto out_err;
 365         err = platform_get_irq_byname(pd, "gdd_mpu");
 366         if (err < 0)
 367                 goto out_err;
 368         omap_ssi->gdd_irq = err;
 369         tasklet_init(&omap_ssi->gdd_tasklet, ssi_gdd_tasklet,
 370                                                         (unsigned long)ssi);
 371         err = devm_request_irq(&ssi->device, omap_ssi->gdd_irq, ssi_gdd_isr,
 372                                                 0, "gdd_mpu", ssi);
 373         if (err < 0) {
 374                 dev_err(&ssi->device, "Request GDD IRQ %d failed (%d)",
 375                                                         omap_ssi->gdd_irq, err);
 376                 goto out_err;
 377         }
 378
 379         omap_ssi->port = devm_kcalloc(&ssi->device, ssi->num_ports,
 380                                       sizeof(*omap_ssi->port), GFP_KERNEL);
 381         if (!omap_ssi->port) {
 382                 err = -ENOMEM;
 383                 goto out_err;
 384         }
 385
 386         omap_ssi->fck = devm_clk_get(&ssi->device, "ssi_ssr_fck");
 387         if (IS_ERR(omap_ssi->fck)) {
 388                 dev_err(&pd->dev, "Could not acquire clock \"ssi_ssr_fck\": %li\n",
 389                         PTR_ERR(omap_ssi->fck));
 390                 err = -ENODEV;
 391                 goto out_err;
 392         }
 393
 394         omap_ssi->fck_nb.notifier_call = ssi_clk_event;
 395         omap_ssi->fck_nb.priority = INT_MAX;
 396         clk_notifier_register(omap_ssi->fck, &omap_ssi->fck_nb);
 397
 398         /* TODO: find register, which can be used to detect context loss */
 399         omap_ssi->get_loss = NULL;
 400
 401         omap_ssi->max_speed = UINT_MAX;
 402         spin_lock_init(&omap_ssi->lock);
 403         err = hsi_register_controller(ssi);
 404
 405         if (err < 0)
 406                 goto out_err;
 407
 408         return 0;
 409
 410 out_err:
 411         ida_free(&platform_omap_ssi_ida, ssi->id);
 412         return err;
 413 }
 414
 415 static int ssi_hw_init(struct hsi_controller *ssi)
 416 {
 417         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 418         int err;
 419
 420         err = pm_runtime_resume_and_get(ssi->device.parent);
 421         if (err < 0) {
 422                 dev_err(&ssi->device, "runtime PM failed %d\n", err);
 423                 return err;
 424         }
 425         /* Resetting GDD */
 426         writel_relaxed(SSI_SWRESET, omap_ssi->gdd + SSI_GDD_GRST_REG);
 427         /* Get FCK rate in kHz */
 428         omap_ssi->fck_rate = DIV_ROUND_CLOSEST(ssi_get_clk_rate(ssi), 1000);
 429         dev_dbg(&ssi->device, "SSI fck rate %lu kHz\n", omap_ssi->fck_rate);
 430
 431         writel_relaxed(SSI_CLK_AUTOGATING_ON, omap_ssi->sys + SSI_GDD_GCR_REG);
 432         omap_ssi->gdd_gcr = SSI_CLK_AUTOGATING_ON;
 433         pm_runtime_put_sync(ssi->device.parent);
 434
 435         return 0;
 436 }
 437
 438 static void ssi_remove_controller(struct hsi_controller *ssi)
 439 {
 440         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 441         int id = ssi->id;
 442         tasklet_kill(&omap_ssi->gdd_tasklet);
 443         hsi_unregister_controller(ssi);
 444         clk_notifier_unregister(omap_ssi->fck, &omap_ssi->fck_nb);
 445         ida_free(&platform_omap_ssi_ida, id);
 446 }
 447
 448 static inline int ssi_of_get_available_ports_count(const struct device_node *np)
 449 {
 450         struct device_node *child;
 451         int num = 0;
 452
 453         for_each_available_child_of_node(np, child)
 454                 if (of_device_is_compatible(child, "ti,omap3-ssi-port"))
 455                         num++;
 456
 457         return num;
 458 }
 459
 460 static int ssi_remove_ports(struct device *dev, void *c)
 461 {
 462         struct platform_device *pdev = to_platform_device(dev);
 463
 464         if (!dev->of_node)
 465                 return 0;
 466
 467         of_node_clear_flag(dev->of_node, OF_POPULATED);
 468         of_device_unregister(pdev);
 469
 470         return 0;
 471 }
 472
 473 static int ssi_probe(struct platform_device *pd)
 474 {
 475         struct platform_device *childpdev;
 476         struct device_node *np = pd->dev.of_node;
 477         struct device_node *child;
 478         struct hsi_controller *ssi;
 479         int err;
 480         int num_ports;
 481
 482         if (!np) {
 483                 dev_err(&pd->dev, "missing device tree data\n");
 484                 return -EINVAL;
 485         }
 486
 487         num_ports = ssi_of_get_available_ports_count(np);
 488
 489         ssi = hsi_alloc_controller(num_ports, GFP_KERNEL);
 490         if (!ssi) {
 491                 dev_err(&pd->dev, "No memory for controller\n");
 492                 return -ENOMEM;
 493         }
 494
 495         platform_set_drvdata(pd, ssi);
 496
 497         err = ssi_add_controller(ssi, pd);
 498         if (err < 0) {
 499                 hsi_put_controller(ssi);
 500                 goto out1;
 501         }
 502
 503         pm_runtime_enable(&pd->dev);
 504
 505         err = ssi_hw_init(ssi);
 506         if (err < 0)
 507                 goto out2;
 508 #ifdef CONFIG_DEBUG_FS
 509         err = ssi_debug_add_ctrl(ssi);
 510         if (err < 0)
 511                 goto out2;
 512 #endif
 513
 514         for_each_available_child_of_node(np, child) {
 515                 if (!of_device_is_compatible(child, "ti,omap3-ssi-port"))
 516                         continue;
 517
 518                 childpdev = of_platform_device_create(child, NULL, &pd->dev);
 519                 if (!childpdev) {
 520                         err = -ENODEV;
 521                         dev_err(&pd->dev, "failed to create ssi controller port\n");
 522                         of_node_put(child);
 523                         goto out3;
 524                 }
 525         }
 526
 527         dev_info(&pd->dev, "ssi controller %d initialized (%d ports)!\n",
 528                 ssi->id, num_ports);
 529         return err;
 530 out3:
 531         device_for_each_child(&pd->dev, NULL, ssi_remove_ports);
 532 out2:
 533         ssi_remove_controller(ssi);
 534         pm_runtime_disable(&pd->dev);
 535 out1:
 536         platform_set_drvdata(pd, NULL);
 537
 538         return err;
 539 }
 540
 541 static void ssi_remove(struct platform_device *pd)
 542 {
 543         struct hsi_controller *ssi = platform_get_drvdata(pd);
 544
 545         /* cleanup of of_platform_populate() call */
 546         device_for_each_child(&pd->dev, NULL, ssi_remove_ports);
 547
 548 #ifdef CONFIG_DEBUG_FS
 549         ssi_debug_remove_ctrl(ssi);
 550 #endif
 551         ssi_remove_controller(ssi);
 552         platform_set_drvdata(pd, NULL);
 553
 554         pm_runtime_disable(&pd->dev);
 555 }
 556
 557 #ifdef CONFIG_PM
 558 static int omap_ssi_runtime_suspend(struct device *dev)
 559 {
 560         struct hsi_controller *ssi = dev_get_drvdata(dev);
 561         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 562
 563         dev_dbg(dev, "runtime suspend!\n");
 564
 565         if (omap_ssi->get_loss)
 566                 omap_ssi->loss_count =
 567                                 omap_ssi->get_loss(ssi->device.parent);
 568
 569         return 0;
 570 }
 571
 572 static int omap_ssi_runtime_resume(struct device *dev)
 573 {
 574         struct hsi_controller *ssi = dev_get_drvdata(dev);
 575         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 576
 577         dev_dbg(dev, "runtime resume!\n");
 578
 579         if ((omap_ssi->get_loss) && (omap_ssi->loss_count ==
 580                                 omap_ssi->get_loss(ssi->device.parent)))
 581                 return 0;
 582
 583         writel_relaxed(omap_ssi->gdd_gcr, omap_ssi->gdd + SSI_GDD_GCR_REG);
 584
 585         return 0;
 586 }
 587
 588 static const struct dev_pm_ops omap_ssi_pm_ops = {
 589         SET_RUNTIME_PM_OPS(omap_ssi_runtime_suspend, omap_ssi_runtime_resume,
 590                 NULL)
 591 };
 592
 593 #define DEV_PM_OPS     (&omap_ssi_pm_ops)
 594 #else
 595 #define DEV_PM_OPS     NULL
 596 #endif
 597
 598 #ifdef CONFIG_OF
 599 static const struct of_device_id omap_ssi_of_match[] = {
 600         { .compatible = "ti,omap3-ssi", },
 601         {},
 602 };
 603 MODULE_DEVICE_TABLE(of, omap_ssi_of_match);
 604 #else
 605 #define omap_ssi_of_match NULL
 606 #endif
 607
 608 static struct platform_driver ssi_pdriver = {
 609         .probe = ssi_probe,
 610         .remove = ssi_remove,
 611         .driver = {
 612                 .name   = "omap_ssi",
 613                 .pm     = DEV_PM_OPS,
 614                 .of_match_table = omap_ssi_of_match,
 615         },
 616 };
 617
 618 static int __init ssi_init(void) {
 619         int ret;
 620
 621         ret = platform_driver_register(&ssi_pdriver);
 622         if (ret)
 623                 return ret;
 624
 625         ret = platform_driver_register(&ssi_port_pdriver);
 626         if (ret) {
 627                 platform_driver_unregister(&ssi_pdriver);
 628                 return ret;
 629         }
 630
 631         return 0;
 632 }
 633 module_init(ssi_init);
 634
 635 static void __exit ssi_exit(void) {
 636         platform_driver_unregister(&ssi_port_pdriver);
 637         platform_driver_unregister(&ssi_pdriver);
 638 }
 639 module_exit(ssi_exit);
 640
 641 MODULE_ALIAS("platform:omap_ssi");
 642 MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
 643 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
 644 MODULE_DESCRIPTION("Synchronous Serial Interface Driver");
 645 MODULE_LICENSE("GPL v2");