drivers/hsi/controllers/omap_ssi_core.c

   1 /* OMAP SSI driver.
   2  *
   3  * Copyright (C) 2010 Nokia Corporation. All rights reserved.
   4  * Copyright (C) 2014 Sebastian Reichel <sre@kernel.org>
   5  *
   6  * Contact: Carlos Chinea <carlos.chinea@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  */
  22
  23 #include <linux/compiler.h>
  24 #include <linux/err.h>
  25 #include <linux/ioport.h>
  26 #include <linux/io.h>
  27 #include <linux/clk.h>
  28 #include <linux/device.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/dma-mapping.h>
  31 #include <linux/dmaengine.h>
  32 #include <linux/delay.h>
  33 #include <linux/seq_file.h>
  34 #include <linux/scatterlist.h>
  35 #include <linux/interrupt.h>
  36 #include <linux/spinlock.h>
  37 #include <linux/debugfs.h>
  38 #include <linux/pinctrl/consumer.h>
  39 #include <linux/pm_runtime.h>
  40 #include <linux/of_platform.h>
  41 #include <linux/hsi/hsi.h>
  42 #include <linux/idr.h>
  43
  44 #include "omap_ssi_regs.h"
  45 #include "omap_ssi.h"
  46
  47 /* For automatically allocated device IDs */
  48 static DEFINE_IDA(platform_omap_ssi_ida);
  49
  50 #ifdef CONFIG_DEBUG_FS
  51 static int ssi_regs_show(struct seq_file *m, void *p __maybe_unused)
  52 {
  53         struct hsi_controller *ssi = m->private;
  54         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  55         void __iomem *sys = omap_ssi->sys;
  56
  57         pm_runtime_get_sync(ssi->device.parent);
  58         seq_printf(m, "REVISION\t: 0x%08x\n",  readl(sys + SSI_REVISION_REG));
  59         seq_printf(m, "SYSCONFIG\t: 0x%08x\n", readl(sys + SSI_SYSCONFIG_REG));
  60         seq_printf(m, "SYSSTATUS\t: 0x%08x\n", readl(sys + SSI_SYSSTATUS_REG));
  61         pm_runtime_put(ssi->device.parent);
  62
  63         return 0;
  64 }
  65
  66 static int ssi_gdd_regs_show(struct seq_file *m, void *p __maybe_unused)
  67 {
  68         struct hsi_controller *ssi = m->private;
  69         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  70         void __iomem *gdd = omap_ssi->gdd;
  71         void __iomem *sys = omap_ssi->sys;
  72         int lch;
  73
  74         pm_runtime_get_sync(ssi->device.parent);
  75
  76         seq_printf(m, "GDD_MPU_STATUS\t: 0x%08x\n",
  77                 readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG));
  78         seq_printf(m, "GDD_MPU_ENABLE\t: 0x%08x\n\n",
  79                 readl(sys + SSI_GDD_MPU_IRQ_ENABLE_REG));
  80         seq_printf(m, "HW_ID\t\t: 0x%08x\n",
  81                                 readl(gdd + SSI_GDD_HW_ID_REG));
  82         seq_printf(m, "PPORT_ID\t: 0x%08x\n",
  83                                 readl(gdd + SSI_GDD_PPORT_ID_REG));
  84         seq_printf(m, "MPORT_ID\t: 0x%08x\n",
  85                                 readl(gdd + SSI_GDD_MPORT_ID_REG));
  86         seq_printf(m, "TEST\t\t: 0x%08x\n",
  87                                 readl(gdd + SSI_GDD_TEST_REG));
  88         seq_printf(m, "GCR\t\t: 0x%08x\n",
  89                                 readl(gdd + SSI_GDD_GCR_REG));
  90
  91         for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) {
  92                 seq_printf(m, "\nGDD LCH %d\n=========\n", lch);
  93                 seq_printf(m, "CSDP\t\t: 0x%04x\n",
  94                                 readw(gdd + SSI_GDD_CSDP_REG(lch)));
  95                 seq_printf(m, "CCR\t\t: 0x%04x\n",
  96                                 readw(gdd + SSI_GDD_CCR_REG(lch)));
  97                 seq_printf(m, "CICR\t\t: 0x%04x\n",
  98                                 readw(gdd + SSI_GDD_CICR_REG(lch)));
  99                 seq_printf(m, "CSR\t\t: 0x%04x\n",
 100                                 readw(gdd + SSI_GDD_CSR_REG(lch)));
 101                 seq_printf(m, "CSSA\t\t: 0x%08x\n",
 102                                 readl(gdd + SSI_GDD_CSSA_REG(lch)));
 103                 seq_printf(m, "CDSA\t\t: 0x%08x\n",
 104                                 readl(gdd + SSI_GDD_CDSA_REG(lch)));
 105                 seq_printf(m, "CEN\t\t: 0x%04x\n",
 106                                 readw(gdd + SSI_GDD_CEN_REG(lch)));
 107                 seq_printf(m, "CSAC\t\t: 0x%04x\n",
 108                                 readw(gdd + SSI_GDD_CSAC_REG(lch)));
 109                 seq_printf(m, "CDAC\t\t: 0x%04x\n",
 110                                 readw(gdd + SSI_GDD_CDAC_REG(lch)));
 111                 seq_printf(m, "CLNK_CTRL\t: 0x%04x\n",
 112                                 readw(gdd + SSI_GDD_CLNK_CTRL_REG(lch)));
 113         }
 114
 115         pm_runtime_put(ssi->device.parent);
 116
 117         return 0;
 118 }
 119
 120 DEFINE_SHOW_ATTRIBUTE(ssi_regs);
 121 DEFINE_SHOW_ATTRIBUTE(ssi_gdd_regs);
 122
 123 static int ssi_debug_add_ctrl(struct hsi_controller *ssi)
 124 {
 125         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 126         struct dentry *dir;
 127
 128         /* SSI controller */
 129         omap_ssi->dir = debugfs_create_dir(dev_name(&ssi->device), NULL);
 130         if (!omap_ssi->dir)
 131                 return -ENOMEM;
 132
 133         debugfs_create_file("regs", S_IRUGO, omap_ssi->dir, ssi,
 134                                                                 &ssi_regs_fops);
 135         /* SSI GDD (DMA) */
 136         dir = debugfs_create_dir("gdd", omap_ssi->dir);
 137         if (!dir)
 138                 goto rback;
 139         debugfs_create_file("regs", S_IRUGO, dir, ssi, &ssi_gdd_regs_fops);
 140
 141         return 0;
 142 rback:
 143         debugfs_remove_recursive(omap_ssi->dir);
 144
 145         return -ENOMEM;
 146 }
 147
 148 static void ssi_debug_remove_ctrl(struct hsi_controller *ssi)
 149 {
 150         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 151
 152         debugfs_remove_recursive(omap_ssi->dir);
 153 }
 154 #endif /* CONFIG_DEBUG_FS */
 155
 156 /*
 157  * FIXME: Horrible HACK needed until we remove the useless wakeline test
 158  * in the CMT. To be removed !!!!
 159  */
 160 void ssi_waketest(struct hsi_client *cl, unsigned int enable)
 161 {
 162         struct hsi_port *port = hsi_get_port(cl);
 163         struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
 164         struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
 165         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 166
 167         omap_port->wktest = !!enable;
 168         if (omap_port->wktest) {
 169                 pm_runtime_get_sync(ssi->device.parent);
 170                 writel_relaxed(SSI_WAKE(0),
 171                                 omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
 172         } else {
 173                 writel_relaxed(SSI_WAKE(0),
 174                                 omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
 175                 pm_runtime_put(ssi->device.parent);
 176         }
 177 }
 178 EXPORT_SYMBOL_GPL(ssi_waketest);
 179
 180 static void ssi_gdd_complete(struct hsi_controller *ssi, unsigned int lch)
 181 {
 182         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 183         struct hsi_msg *msg = omap_ssi->gdd_trn[lch].msg;
 184         struct hsi_port *port = to_hsi_port(msg->cl->device.parent);
 185         struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
 186         unsigned int dir;
 187         u32 csr;
 188         u32 val;
 189
 190         spin_lock(&omap_ssi->lock);
 191
 192         val = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
 193         val &= ~SSI_GDD_LCH(lch);
 194         writel_relaxed(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
 195
 196         if (msg->ttype == HSI_MSG_READ) {
 197                 dir = DMA_FROM_DEVICE;
 198                 val = SSI_DATAAVAILABLE(msg->channel);
 199                 pm_runtime_put(omap_port->pdev);
 200         } else {
 201                 dir = DMA_TO_DEVICE;
 202                 val = SSI_DATAACCEPT(msg->channel);
 203                 /* Keep clocks reference for write pio event */
 204         }
 205         dma_unmap_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents, dir);
 206         csr = readw(omap_ssi->gdd + SSI_GDD_CSR_REG(lch));
 207         omap_ssi->gdd_trn[lch].msg = NULL; /* release GDD lch */
 208         dev_dbg(&port->device, "DMA completed ch %d ttype %d\n",
 209                                 msg->channel, msg->ttype);
 210         spin_unlock(&omap_ssi->lock);
 211         if (csr & SSI_CSR_TOUR) { /* Timeout error */
 212                 msg->status = HSI_STATUS_ERROR;
 213                 msg->actual_len = 0;
 214                 spin_lock(&omap_port->lock);
 215                 list_del(&msg->link); /* Dequeue msg */
 216                 spin_unlock(&omap_port->lock);
 217
 218                 list_add_tail(&msg->link, &omap_port->errqueue);
 219                 schedule_delayed_work(&omap_port->errqueue_work, 0);
 220                 return;
 221         }
 222         spin_lock(&omap_port->lock);
 223         val |= readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
 224         writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
 225         spin_unlock(&omap_port->lock);
 226
 227         msg->status = HSI_STATUS_COMPLETED;
 228         msg->actual_len = sg_dma_len(msg->sgt.sgl);
 229 }
 230
 231 static void ssi_gdd_tasklet(unsigned long dev)
 232 {
 233         struct hsi_controller *ssi = (struct hsi_controller *)dev;
 234         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 235         void __iomem *sys = omap_ssi->sys;
 236         unsigned int lch;
 237         u32 status_reg;
 238
 239         pm_runtime_get(ssi->device.parent);
 240
 241         if (!pm_runtime_active(ssi->device.parent)) {
 242                 dev_warn(ssi->device.parent, "ssi_gdd_tasklet called without runtime PM!\n");
 243                 pm_runtime_put(ssi->device.parent);
 244                 return;
 245         }
 246
 247         status_reg = readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG);
 248         for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) {
 249                 if (status_reg & SSI_GDD_LCH(lch))
 250                         ssi_gdd_complete(ssi, lch);
 251         }
 252         writel_relaxed(status_reg, sys + SSI_GDD_MPU_IRQ_STATUS_REG);
 253         status_reg = readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG);
 254
 255         pm_runtime_put(ssi->device.parent);
 256
 257         if (status_reg)
 258                 tasklet_hi_schedule(&omap_ssi->gdd_tasklet);
 259         else
 260                 enable_irq(omap_ssi->gdd_irq);
 261
 262 }
 263
 264 static irqreturn_t ssi_gdd_isr(int irq, void *ssi)
 265 {
 266         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 267
 268         tasklet_hi_schedule(&omap_ssi->gdd_tasklet);
 269         disable_irq_nosync(irq);
 270
 271         return IRQ_HANDLED;
 272 }
 273
 274 static unsigned long ssi_get_clk_rate(struct hsi_controller *ssi)
 275 {
 276         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 277         unsigned long rate = clk_get_rate(omap_ssi->fck);
 278         return rate;
 279 }
 280
 281 static int ssi_clk_event(struct notifier_block *nb, unsigned long event,
 282                                                                 void *data)
 283 {
 284         struct omap_ssi_controller *omap_ssi = container_of(nb,
 285                                         struct omap_ssi_controller, fck_nb);
 286         struct hsi_controller *ssi = to_hsi_controller(omap_ssi->dev);
 287         struct clk_notifier_data *clk_data = data;
 288         struct omap_ssi_port *omap_port;
 289         int i;
 290
 291         switch (event) {
 292         case PRE_RATE_CHANGE:
 293                 dev_dbg(&ssi->device, "pre rate change\n");
 294
 295                 for (i = 0; i < ssi->num_ports; i++) {
 296                         omap_port = omap_ssi->port[i];
 297
 298                         if (!omap_port)
 299                                 continue;
 300
 301                         /* Workaround for SWBREAK + CAwake down race in CMT */
 302                         disable_irq(omap_port->wake_irq);
 303
 304                         /* stop all ssi communication */
 305                         pinctrl_pm_select_idle_state(omap_port->pdev);
 306                         udelay(1); /* wait for racing frames */
 307                 }
 308
 309                 break;
 310         case ABORT_RATE_CHANGE:
 311                 dev_dbg(&ssi->device, "abort rate change\n");
 312                 /* Fall through */
 313         case POST_RATE_CHANGE:
 314                 dev_dbg(&ssi->device, "post rate change (%lu -> %lu)\n",
 315                         clk_data->old_rate, clk_data->new_rate);
 316                 omap_ssi->fck_rate = DIV_ROUND_CLOSEST(clk_data->new_rate, 1000); /* kHz */
 317
 318                 for (i = 0; i < ssi->num_ports; i++) {
 319                         omap_port = omap_ssi->port[i];
 320
 321                         if (!omap_port)
 322                                 continue;
 323
 324                         omap_ssi_port_update_fclk(ssi, omap_port);
 325
 326                         /* resume ssi communication */
 327                         pinctrl_pm_select_default_state(omap_port->pdev);
 328                         enable_irq(omap_port->wake_irq);
 329                 }
 330
 331                 break;
 332         default:
 333                 break;
 334         }
 335
 336         return NOTIFY_DONE;
 337 }
 338
 339 static int ssi_get_iomem(struct platform_device *pd,
 340                 const char *name, void __iomem **pbase, dma_addr_t *phy)
 341 {
 342         struct resource *mem;
 343         void __iomem *base;
 344         struct hsi_controller *ssi = platform_get_drvdata(pd);
 345
 346         mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name);
 347         base = devm_ioremap_resource(&ssi->device, mem);
 348         if (IS_ERR(base))
 349                 return PTR_ERR(base);
 350
 351         *pbase = base;
 352
 353         if (phy)
 354                 *phy = mem->start;
 355
 356         return 0;
 357 }
 358
 359 static int ssi_add_controller(struct hsi_controller *ssi,
 360                                                 struct platform_device *pd)
 361 {
 362         struct omap_ssi_controller *omap_ssi;
 363         int err;
 364
 365         omap_ssi = devm_kzalloc(&ssi->device, sizeof(*omap_ssi), GFP_KERNEL);
 366         if (!omap_ssi)
 367                 return -ENOMEM;
 368
 369         err = ida_simple_get(&platform_omap_ssi_ida, 0, 0, GFP_KERNEL);
 370         if (err < 0)
 371                 goto out_err;
 372         ssi->id = err;
 373
 374         ssi->owner = THIS_MODULE;
 375         ssi->device.parent = &pd->dev;
 376         dev_set_name(&ssi->device, "ssi%d", ssi->id);
 377         hsi_controller_set_drvdata(ssi, omap_ssi);
 378         omap_ssi->dev = &ssi->device;
 379         err = ssi_get_iomem(pd, "sys", &omap_ssi->sys, NULL);
 380         if (err < 0)
 381                 goto out_err;
 382         err = ssi_get_iomem(pd, "gdd", &omap_ssi->gdd, NULL);
 383         if (err < 0)
 384                 goto out_err;
 385         err = platform_get_irq_byname(pd, "gdd_mpu");
 386         if (err < 0) {
 387                 dev_err(&pd->dev, "GDD IRQ resource missing\n");
 388                 goto out_err;
 389         }
 390         omap_ssi->gdd_irq = err;
 391         tasklet_init(&omap_ssi->gdd_tasklet, ssi_gdd_tasklet,
 392                                                         (unsigned long)ssi);
 393         err = devm_request_irq(&ssi->device, omap_ssi->gdd_irq, ssi_gdd_isr,
 394                                                 0, "gdd_mpu", ssi);
 395         if (err < 0) {
 396                 dev_err(&ssi->device, "Request GDD IRQ %d failed (%d)",
 397                                                         omap_ssi->gdd_irq, err);
 398                 goto out_err;
 399         }
 400
 401         omap_ssi->port = devm_kcalloc(&ssi->device, ssi->num_ports,
 402                                       sizeof(*omap_ssi->port), GFP_KERNEL);
 403         if (!omap_ssi->port) {
 404                 err = -ENOMEM;
 405                 goto out_err;
 406         }
 407
 408         omap_ssi->fck = devm_clk_get(&ssi->device, "ssi_ssr_fck");
 409         if (IS_ERR(omap_ssi->fck)) {
 410                 dev_err(&pd->dev, "Could not acquire clock \"ssi_ssr_fck\": %li\n",
 411                         PTR_ERR(omap_ssi->fck));
 412                 err = -ENODEV;
 413                 goto out_err;
 414         }
 415
 416         omap_ssi->fck_nb.notifier_call = ssi_clk_event;
 417         omap_ssi->fck_nb.priority = INT_MAX;
 418         clk_notifier_register(omap_ssi->fck, &omap_ssi->fck_nb);
 419
 420         /* TODO: find register, which can be used to detect context loss */
 421         omap_ssi->get_loss = NULL;
 422
 423         omap_ssi->max_speed = UINT_MAX;
 424         spin_lock_init(&omap_ssi->lock);
 425         err = hsi_register_controller(ssi);
 426
 427         if (err < 0)
 428                 goto out_err;
 429
 430         return 0;
 431
 432 out_err:
 433         ida_simple_remove(&platform_omap_ssi_ida, ssi->id);
 434         return err;
 435 }
 436
 437 static int ssi_hw_init(struct hsi_controller *ssi)
 438 {
 439         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 440         int err;
 441
 442         err = pm_runtime_get_sync(ssi->device.parent);
 443         if (err < 0) {
 444                 dev_err(&ssi->device, "runtime PM failed %d\n", err);
 445                 return err;
 446         }
 447         /* Resetting GDD */
 448         writel_relaxed(SSI_SWRESET, omap_ssi->gdd + SSI_GDD_GRST_REG);
 449         /* Get FCK rate in kHz */
 450         omap_ssi->fck_rate = DIV_ROUND_CLOSEST(ssi_get_clk_rate(ssi), 1000);
 451         dev_dbg(&ssi->device, "SSI fck rate %lu kHz\n", omap_ssi->fck_rate);
 452
 453         writel_relaxed(SSI_CLK_AUTOGATING_ON, omap_ssi->sys + SSI_GDD_GCR_REG);
 454         omap_ssi->gdd_gcr = SSI_CLK_AUTOGATING_ON;
 455         pm_runtime_put_sync(ssi->device.parent);
 456
 457         return 0;
 458 }
 459
 460 static void ssi_remove_controller(struct hsi_controller *ssi)
 461 {
 462         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 463         int id = ssi->id;
 464         tasklet_kill(&omap_ssi->gdd_tasklet);
 465         hsi_unregister_controller(ssi);
 466         clk_notifier_unregister(omap_ssi->fck, &omap_ssi->fck_nb);
 467         ida_simple_remove(&platform_omap_ssi_ida, id);
 468 }
 469
 470 static inline int ssi_of_get_available_ports_count(const struct device_node *np)
 471 {
 472         struct device_node *child;
 473         int num = 0;
 474
 475         for_each_available_child_of_node(np, child)
 476                 if (of_device_is_compatible(child, "ti,omap3-ssi-port"))
 477                         num++;
 478
 479         return num;
 480 }
 481
 482 static int ssi_remove_ports(struct device *dev, void *c)
 483 {
 484         struct platform_device *pdev = to_platform_device(dev);
 485
 486         if (!dev->of_node)
 487                 return 0;
 488
 489         of_node_clear_flag(dev->of_node, OF_POPULATED);
 490         of_device_unregister(pdev);
 491
 492         return 0;
 493 }
 494
 495 static int ssi_probe(struct platform_device *pd)
 496 {
 497         struct platform_device *childpdev;
 498         struct device_node *np = pd->dev.of_node;
 499         struct device_node *child;
 500         struct hsi_controller *ssi;
 501         int err;
 502         int num_ports;
 503
 504         if (!np) {
 505                 dev_err(&pd->dev, "missing device tree data\n");
 506                 return -EINVAL;
 507         }
 508
 509         num_ports = ssi_of_get_available_ports_count(np);
 510
 511         ssi = hsi_alloc_controller(num_ports, GFP_KERNEL);
 512         if (!ssi) {
 513                 dev_err(&pd->dev, "No memory for controller\n");
 514                 return -ENOMEM;
 515         }
 516
 517         platform_set_drvdata(pd, ssi);
 518
 519         err = ssi_add_controller(ssi, pd);
 520         if (err < 0)
 521                 goto out1;
 522
 523         pm_runtime_enable(&pd->dev);
 524
 525         err = ssi_hw_init(ssi);
 526         if (err < 0)
 527                 goto out2;
 528 #ifdef CONFIG_DEBUG_FS
 529         err = ssi_debug_add_ctrl(ssi);
 530         if (err < 0)
 531                 goto out2;
 532 #endif
 533
 534         for_each_available_child_of_node(np, child) {
 535                 if (!of_device_is_compatible(child, "ti,omap3-ssi-port"))
 536                         continue;
 537
 538                 childpdev = of_platform_device_create(child, NULL, &pd->dev);
 539                 if (!childpdev) {
 540                         err = -ENODEV;
 541                         dev_err(&pd->dev, "failed to create ssi controller port\n");
 542                         goto out3;
 543                 }
 544         }
 545
 546         dev_info(&pd->dev, "ssi controller %d initialized (%d ports)!\n",
 547                 ssi->id, num_ports);
 548         return err;
 549 out3:
 550         device_for_each_child(&pd->dev, NULL, ssi_remove_ports);
 551 out2:
 552         ssi_remove_controller(ssi);
 553 out1:
 554         platform_set_drvdata(pd, NULL);
 555         pm_runtime_disable(&pd->dev);
 556
 557         return err;
 558 }
 559
 560 static int ssi_remove(struct platform_device *pd)
 561 {
 562         struct hsi_controller *ssi = platform_get_drvdata(pd);
 563
 564         /* cleanup of of_platform_populate() call */
 565         device_for_each_child(&pd->dev, NULL, ssi_remove_ports);
 566
 567 #ifdef CONFIG_DEBUG_FS
 568         ssi_debug_remove_ctrl(ssi);
 569 #endif
 570         ssi_remove_controller(ssi);
 571         platform_set_drvdata(pd, NULL);
 572
 573         pm_runtime_disable(&pd->dev);
 574
 575         return 0;
 576 }
 577
 578 #ifdef CONFIG_PM
 579 static int omap_ssi_runtime_suspend(struct device *dev)
 580 {
 581         struct hsi_controller *ssi = dev_get_drvdata(dev);
 582         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 583
 584         dev_dbg(dev, "runtime suspend!\n");
 585
 586         if (omap_ssi->get_loss)
 587                 omap_ssi->loss_count =
 588                                 omap_ssi->get_loss(ssi->device.parent);
 589
 590         return 0;
 591 }
 592
 593 static int omap_ssi_runtime_resume(struct device *dev)
 594 {
 595         struct hsi_controller *ssi = dev_get_drvdata(dev);
 596         struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
 597
 598         dev_dbg(dev, "runtime resume!\n");
 599
 600         if ((omap_ssi->get_loss) && (omap_ssi->loss_count ==
 601                                 omap_ssi->get_loss(ssi->device.parent)))
 602                 return 0;
 603
 604         writel_relaxed(omap_ssi->gdd_gcr, omap_ssi->gdd + SSI_GDD_GCR_REG);
 605
 606         return 0;
 607 }
 608
 609 static const struct dev_pm_ops omap_ssi_pm_ops = {
 610         SET_RUNTIME_PM_OPS(omap_ssi_runtime_suspend, omap_ssi_runtime_resume,
 611                 NULL)
 612 };
 613
 614 #define DEV_PM_OPS     (&omap_ssi_pm_ops)
 615 #else
 616 #define DEV_PM_OPS     NULL
 617 #endif
 618
 619 #ifdef CONFIG_OF
 620 static const struct of_device_id omap_ssi_of_match[] = {
 621         { .compatible = "ti,omap3-ssi", },
 622         {},
 623 };
 624 MODULE_DEVICE_TABLE(of, omap_ssi_of_match);
 625 #else
 626 #define omap_ssi_of_match NULL
 627 #endif
 628
 629 static struct platform_driver ssi_pdriver = {
 630         .probe = ssi_probe,
 631         .remove = ssi_remove,
 632         .driver = {
 633                 .name   = "omap_ssi",
 634                 .pm     = DEV_PM_OPS,
 635                 .of_match_table = omap_ssi_of_match,
 636         },
 637 };
 638
 639 static int __init ssi_init(void) {
 640         int ret;
 641
 642         ret = platform_driver_register(&ssi_pdriver);
 643         if (ret)
 644                 return ret;
 645
 646         return platform_driver_register(&ssi_port_pdriver);
 647 }
 648 module_init(ssi_init);
 649
 650 static void __exit ssi_exit(void) {
 651         platform_driver_unregister(&ssi_port_pdriver);
 652         platform_driver_unregister(&ssi_pdriver);
 653 }
 654 module_exit(ssi_exit);
 655
 656 MODULE_ALIAS("platform:omap_ssi");
 657 MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
 658 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
 659 MODULE_DESCRIPTION("Synchronous Serial Interface Driver");
 660 MODULE_LICENSE("GPL v2");