drivers/mailbox/zynqmp-ipi-mailbox.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Xilinx Inter Processor Interrupt(IPI) Mailbox Driver
   4  *
   5  * Copyright (C) 2018 Xilinx, Inc.
   6  */
   7
   8 #include <linux/arm-smccc.h>
   9 #include <linux/delay.h>
  10 #include <linux/device.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/io.h>
  13 #include <linux/kernel.h>
  14 #include <linux/mailbox_controller.h>
  15 #include <linux/mailbox/zynqmp-ipi-message.h>
  16 #include <linux/module.h>
  17 #include <linux/of.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_device.h>
  20 #include <linux/of_irq.h>
  21 #include <linux/platform_device.h>
  22
  23 /* IPI agent ID any */
  24 #define IPI_ID_ANY 0xFFUL
  25
  26 /* indicate if ZynqMP IPI mailbox driver uses SMC calls or HVC calls */
  27 #define USE_SMC 0
  28 #define USE_HVC 1
  29
  30 /* Default IPI SMC function IDs */
  31 #define SMC_IPI_MAILBOX_OPEN            0x82001000U
  32 #define SMC_IPI_MAILBOX_RELEASE         0x82001001U
  33 #define SMC_IPI_MAILBOX_STATUS_ENQUIRY  0x82001002U
  34 #define SMC_IPI_MAILBOX_NOTIFY          0x82001003U
  35 #define SMC_IPI_MAILBOX_ACK             0x82001004U
  36 #define SMC_IPI_MAILBOX_ENABLE_IRQ      0x82001005U
  37 #define SMC_IPI_MAILBOX_DISABLE_IRQ     0x82001006U
  38
  39 /* IPI SMC Macros */
  40 #define IPI_SMC_ENQUIRY_DIRQ_MASK       0x00000001UL /* Flag to indicate if
  41                                                       * notification interrupt
  42                                                       * to be disabled.
  43                                                       */
  44 #define IPI_SMC_ACK_EIRQ_MASK           0x00000001UL /* Flag to indicate if
  45                                                       * notification interrupt
  46                                                       * to be enabled.
  47                                                       */
  48
  49 /* IPI mailbox status */
  50 #define IPI_MB_STATUS_IDLE              0
  51 #define IPI_MB_STATUS_SEND_PENDING      1
  52 #define IPI_MB_STATUS_RECV_PENDING      2
  53
  54 #define IPI_MB_CHNL_TX  0 /* IPI mailbox TX channel */
  55 #define IPI_MB_CHNL_RX  1 /* IPI mailbox RX channel */
  56
  57 /**
  58  * struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel
  59  * @is_opened: indicate if the IPI channel is opened
  60  * @req_buf: local to remote request buffer start address
  61  * @resp_buf: local to remote response buffer start address
  62  * @req_buf_size: request buffer size
  63  * @resp_buf_size: response buffer size
  64  * @rx_buf: receive buffer to pass received message to client
  65  * @chan_type: channel type
  66  */
  67 struct zynqmp_ipi_mchan {
  68         int is_opened;
  69         void __iomem *req_buf;
  70         void __iomem *resp_buf;
  71         void *rx_buf;
  72         size_t req_buf_size;
  73         size_t resp_buf_size;
  74         unsigned int chan_type;
  75 };
  76
  77 /**
  78  * struct zynqmp_ipi_mbox - Description of a ZynqMP IPI mailbox
  79  *                          platform data.
  80  * @pdata:                pointer to the IPI private data
  81  * @dev:                  device pointer corresponding to the Xilinx ZynqMP
  82  *                        IPI mailbox
  83  * @remote_id:            remote IPI agent ID
  84  * @mbox:                 mailbox Controller
  85  * @mchans:               array for channels, tx channel and rx channel.
  86  * @irq:                  IPI agent interrupt ID
  87  */
  88 struct zynqmp_ipi_mbox {
  89         struct zynqmp_ipi_pdata *pdata;
  90         struct device dev;
  91         u32 remote_id;
  92         struct mbox_controller mbox;
  93         struct zynqmp_ipi_mchan mchans[2];
  94 };
  95
  96 /**
  97  * struct zynqmp_ipi_pdata - Description of z ZynqMP IPI agent platform data.
  98  *
  99  * @dev:                  device pointer corresponding to the Xilinx ZynqMP
 100  *                        IPI agent
 101  * @irq:                  IPI agent interrupt ID
 102  * @method:               IPI SMC or HVC is going to be used
 103  * @local_id:             local IPI agent ID
 104  * @num_mboxes:           number of mailboxes of this IPI agent
 105  * @ipi_mboxes:           IPI mailboxes of this IPI agent
 106  */
 107 struct zynqmp_ipi_pdata {
 108         struct device *dev;
 109         int irq;
 110         unsigned int method;
 111         u32 local_id;
 112         int num_mboxes;
 113         struct zynqmp_ipi_mbox *ipi_mboxes;
 114 };
 115
 116 static struct device_driver zynqmp_ipi_mbox_driver = {
 117         .owner = THIS_MODULE,
 118         .name = "zynqmp-ipi-mbox",
 119 };
 120
 121 static void zynqmp_ipi_fw_call(struct zynqmp_ipi_mbox *ipi_mbox,
 122                                unsigned long a0, unsigned long a3,
 123                                struct arm_smccc_res *res)
 124 {
 125         struct zynqmp_ipi_pdata *pdata = ipi_mbox->pdata;
 126         unsigned long a1, a2;
 127
 128         a1 = pdata->local_id;
 129         a2 = ipi_mbox->remote_id;
 130         if (pdata->method == USE_SMC)
 131                 arm_smccc_smc(a0, a1, a2, a3, 0, 0, 0, 0, res);
 132         else
 133                 arm_smccc_hvc(a0, a1, a2, a3, 0, 0, 0, 0, res);
 134 }
 135
 136 /**
 137  * zynqmp_ipi_interrupt - Interrupt handler for IPI notification
 138  *
 139  * @irq:  Interrupt number
 140  * @data: ZynqMP IPI mailbox platform data.
 141  *
 142  * Return: -EINVAL if there is no instance
 143  * IRQ_NONE if the interrupt is not ours.
 144  * IRQ_HANDLED if the rx interrupt was successfully handled.
 145  */
 146 static irqreturn_t zynqmp_ipi_interrupt(int irq, void *data)
 147 {
 148         struct zynqmp_ipi_pdata *pdata = data;
 149         struct mbox_chan *chan;
 150         struct zynqmp_ipi_mbox *ipi_mbox;
 151         struct zynqmp_ipi_mchan *mchan;
 152         struct zynqmp_ipi_message *msg;
 153         u64 arg0, arg3;
 154         struct arm_smccc_res res;
 155         int ret, i;
 156
 157         (void)irq;
 158         arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
 159         arg3 = IPI_SMC_ENQUIRY_DIRQ_MASK;
 160         for (i = 0; i < pdata->num_mboxes; i++) {
 161                 ipi_mbox = &pdata->ipi_mboxes[i];
 162                 mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
 163                 chan = &ipi_mbox->mbox.chans[IPI_MB_CHNL_RX];
 164                 zynqmp_ipi_fw_call(ipi_mbox, arg0, arg3, &res);
 165                 ret = (int)(res.a0 & 0xFFFFFFFF);
 166                 if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
 167                         if (mchan->is_opened) {
 168                                 msg = mchan->rx_buf;
 169                                 msg->len = mchan->req_buf_size;
 170                                 memcpy_fromio(msg->data, mchan->req_buf,
 171                                               msg->len);
 172                                 mbox_chan_received_data(chan, (void *)msg);
 173                                 return IRQ_HANDLED;
 174                         }
 175                 }
 176         }
 177         return IRQ_NONE;
 178 }
 179
 180 /**
 181  * zynqmp_ipi_peek_data - Peek to see if there are any rx messages.
 182  *
 183  * @chan: Channel Pointer
 184  *
 185  * Return: 'true' if there is pending rx data, 'false' if there is none.
 186  */
 187 static bool zynqmp_ipi_peek_data(struct mbox_chan *chan)
 188 {
 189         struct device *dev = chan->mbox->dev;
 190         struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
 191         struct zynqmp_ipi_mchan *mchan = chan->con_priv;
 192         int ret;
 193         u64 arg0;
 194         struct arm_smccc_res res;
 195
 196         if (WARN_ON(!ipi_mbox)) {
 197                 dev_err(dev, "no platform drv data??\n");
 198                 return false;
 199         }
 200
 201         arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
 202         zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
 203         ret = (int)(res.a0 & 0xFFFFFFFF);
 204
 205         if (mchan->chan_type == IPI_MB_CHNL_TX) {
 206                 /* TX channel, check if the message has been acked
 207                  * by the remote, if yes, response is available.
 208                  */
 209                 if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
 210                         return false;
 211                 else
 212                         return true;
 213         } else if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
 214                 /* RX channel, check if there is message arrived. */
 215                 return true;
 216         }
 217         return false;
 218 }
 219
 220 /**
 221  * zynqmp_ipi_last_tx_done - See if the last tx message is sent
 222  *
 223  * @chan: Channel pointer
 224  *
 225  * Return: 'true' is no pending tx data, 'false' if there are any.
 226  */
 227 static bool zynqmp_ipi_last_tx_done(struct mbox_chan *chan)
 228 {
 229         struct device *dev = chan->mbox->dev;
 230         struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
 231         struct zynqmp_ipi_mchan *mchan = chan->con_priv;
 232         int ret;
 233         u64 arg0;
 234         struct arm_smccc_res res;
 235
 236         if (WARN_ON(!ipi_mbox)) {
 237                 dev_err(dev, "no platform drv data??\n");
 238                 return false;
 239         }
 240
 241         if (mchan->chan_type == IPI_MB_CHNL_TX) {
 242                 /* We only need to check if the message been taken
 243                  * by the remote in the TX channel
 244                  */
 245                 arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
 246                 zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
 247                 /* Check the SMC call status, a0 of the result */
 248                 ret = (int)(res.a0 & 0xFFFFFFFF);
 249                 if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
 250                         return false;
 251                 return true;
 252         }
 253         /* Always true for the response message in RX channel */
 254         return true;
 255 }
 256
 257 /**
 258  * zynqmp_ipi_send_data - Send data
 259  *
 260  * @chan: Channel Pointer
 261  * @data: Message Pointer
 262  *
 263  * Return: 0 if all goes good, else appropriate error messages.
 264  */
 265 static int zynqmp_ipi_send_data(struct mbox_chan *chan, void *data)
 266 {
 267         struct device *dev = chan->mbox->dev;
 268         struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
 269         struct zynqmp_ipi_mchan *mchan = chan->con_priv;
 270         struct zynqmp_ipi_message *msg = data;
 271         u64 arg0;
 272         struct arm_smccc_res res;
 273
 274         if (WARN_ON(!ipi_mbox)) {
 275                 dev_err(dev, "no platform drv data??\n");
 276                 return -EINVAL;
 277         }
 278
 279         if (mchan->chan_type == IPI_MB_CHNL_TX) {
 280                 /* Send request message */
 281                 if (msg && msg->len > mchan->req_buf_size) {
 282                         dev_err(dev, "channel %d message length %u > max %lu\n",
 283                                 mchan->chan_type, (unsigned int)msg->len,
 284                                 mchan->req_buf_size);
 285                         return -EINVAL;
 286                 }
 287                 if (msg && msg->len)
 288                         memcpy_toio(mchan->req_buf, msg->data, msg->len);
 289                 /* Kick IPI mailbox to send message */
 290                 arg0 = SMC_IPI_MAILBOX_NOTIFY;
 291                 zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
 292         } else {
 293                 /* Send response message */
 294                 if (msg && msg->len > mchan->resp_buf_size) {
 295                         dev_err(dev, "channel %d message length %u > max %lu\n",
 296                                 mchan->chan_type, (unsigned int)msg->len,
 297                                 mchan->resp_buf_size);
 298                         return -EINVAL;
 299                 }
 300                 if (msg && msg->len)
 301                         memcpy_toio(mchan->resp_buf, msg->data, msg->len);
 302                 arg0 = SMC_IPI_MAILBOX_ACK;
 303                 zynqmp_ipi_fw_call(ipi_mbox, arg0, IPI_SMC_ACK_EIRQ_MASK,
 304                                    &res);
 305         }
 306         return 0;
 307 }
 308
 309 /**
 310  * zynqmp_ipi_startup - Startup the IPI channel
 311  *
 312  * @chan: Channel pointer
 313  *
 314  * Return: 0 if all goes good, else return corresponding error message
 315  */
 316 static int zynqmp_ipi_startup(struct mbox_chan *chan)
 317 {
 318         struct device *dev = chan->mbox->dev;
 319         struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
 320         struct zynqmp_ipi_mchan *mchan = chan->con_priv;
 321         u64 arg0;
 322         struct arm_smccc_res res;
 323         int ret = 0;
 324         unsigned int nchan_type;
 325
 326         if (mchan->is_opened)
 327                 return 0;
 328
 329         /* If no channel has been opened, open the IPI mailbox */
 330         nchan_type = (mchan->chan_type + 1) % 2;
 331         if (!ipi_mbox->mchans[nchan_type].is_opened) {
 332                 arg0 = SMC_IPI_MAILBOX_OPEN;
 333                 zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
 334                 /* Check the SMC call status, a0 of the result */
 335                 ret = (int)(res.a0 & 0xFFFFFFFF);
 336                 if (ret < 0) {
 337                         dev_err(dev, "SMC to open the IPI channel failed.\n");
 338                         return ret;
 339                 }
 340                 ret = 0;
 341         }
 342
 343         /* If it is RX channel, enable the IPI notification interrupt */
 344         if (mchan->chan_type == IPI_MB_CHNL_RX) {
 345                 arg0 = SMC_IPI_MAILBOX_ENABLE_IRQ;
 346                 zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
 347         }
 348         mchan->is_opened = 1;
 349
 350         return ret;
 351 }
 352
 353 /**
 354  * zynqmp_ipi_shutdown - Shutdown the IPI channel
 355  *
 356  * @chan: Channel pointer
 357  */
 358 static void zynqmp_ipi_shutdown(struct mbox_chan *chan)
 359 {
 360         struct device *dev = chan->mbox->dev;
 361         struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
 362         struct zynqmp_ipi_mchan *mchan = chan->con_priv;
 363         u64 arg0;
 364         struct arm_smccc_res res;
 365         unsigned int chan_type;
 366
 367         if (!mchan->is_opened)
 368                 return;
 369
 370         /* If it is RX channel, disable notification interrupt */
 371         chan_type = mchan->chan_type;
 372         if (chan_type == IPI_MB_CHNL_RX) {
 373                 arg0 = SMC_IPI_MAILBOX_DISABLE_IRQ;
 374                 zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
 375         }
 376         /* Release IPI mailbox if no other channel is opened */
 377         chan_type = (chan_type + 1) % 2;
 378         if (!ipi_mbox->mchans[chan_type].is_opened) {
 379                 arg0 = SMC_IPI_MAILBOX_RELEASE;
 380                 zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
 381         }
 382
 383         mchan->is_opened = 0;
 384 }
 385
 386 /* ZynqMP IPI mailbox operations */
 387 static const struct mbox_chan_ops zynqmp_ipi_chan_ops = {
 388         .startup = zynqmp_ipi_startup,
 389         .shutdown = zynqmp_ipi_shutdown,
 390         .peek_data = zynqmp_ipi_peek_data,
 391         .last_tx_done = zynqmp_ipi_last_tx_done,
 392         .send_data = zynqmp_ipi_send_data,
 393 };
 394
 395 /**
 396  * zynqmp_ipi_of_xlate - Translate of phandle to IPI mailbox channel
 397  *
 398  * @mbox: mailbox controller pointer
 399  * @p:    phandle pointer
 400  *
 401  * Return: Mailbox channel, else return error pointer.
 402  */
 403 static struct mbox_chan *zynqmp_ipi_of_xlate(struct mbox_controller *mbox,
 404                                              const struct of_phandle_args *p)
 405 {
 406         struct mbox_chan *chan;
 407         struct device *dev = mbox->dev;
 408         unsigned int chan_type;
 409
 410         /* Only supports TX and RX channels */
 411         chan_type = p->args[0];
 412         if (chan_type != IPI_MB_CHNL_TX && chan_type != IPI_MB_CHNL_RX) {
 413                 dev_err(dev, "req chnl failure: invalid chnl type %u.\n",
 414                         chan_type);
 415                 return ERR_PTR(-EINVAL);
 416         }
 417         chan = &mbox->chans[chan_type];
 418         return chan;
 419 }
 420
 421 static const struct of_device_id zynqmp_ipi_of_match[] = {
 422         { .compatible = "xlnx,zynqmp-ipi-mailbox" },
 423         {},
 424 };
 425 MODULE_DEVICE_TABLE(of, zynqmp_ipi_of_match);
 426
 427 /**
 428  * zynqmp_ipi_mbox_get_buf_res - Get buffer resource from the IPI dev node
 429  *
 430  * @node: IPI mbox device child node
 431  * @name: name of the IPI buffer
 432  * @res: pointer to where the resource information will be stored.
 433  *
 434  * Return: 0 for success, negative value for failure
 435  */
 436 static int zynqmp_ipi_mbox_get_buf_res(struct device_node *node,
 437                                        const char *name,
 438                                        struct resource *res)
 439 {
 440         int ret, index;
 441
 442         index = of_property_match_string(node, "reg-names", name);
 443         if (index >= 0) {
 444                 ret = of_address_to_resource(node, index, res);
 445                 if (ret < 0)
 446                         return -EINVAL;
 447                 return 0;
 448         }
 449         return -ENODEV;
 450 }
 451
 452 /**
 453  * zynqmp_ipi_mbox_dev_release() - release the existence of a ipi mbox dev
 454  *
 455  * @dev: the ipi mailbox device
 456  *
 457  * This is to avoid the no device release() function kernel warning.
 458  *
 459  */
 460 static void zynqmp_ipi_mbox_dev_release(struct device *dev)
 461 {
 462         (void)dev;
 463 }
 464
 465 /**
 466  * zynqmp_ipi_mbox_probe - probe IPI mailbox resource from device node
 467  *
 468  * @ipi_mbox: pointer to IPI mailbox private data structure
 469  * @node: IPI mailbox device node
 470  *
 471  * Return: 0 for success, negative value for failure
 472  */
 473 static int zynqmp_ipi_mbox_probe(struct zynqmp_ipi_mbox *ipi_mbox,
 474                                  struct device_node *node)
 475 {
 476         struct zynqmp_ipi_mchan *mchan;
 477         struct mbox_chan *chans;
 478         struct mbox_controller *mbox;
 479         struct resource res;
 480         struct device *dev, *mdev;
 481         const char *name;
 482         int ret;
 483
 484         dev = ipi_mbox->pdata->dev;
 485         /* Initialize dev for IPI mailbox */
 486         ipi_mbox->dev.parent = dev;
 487         ipi_mbox->dev.release = NULL;
 488         ipi_mbox->dev.of_node = node;
 489         dev_set_name(&ipi_mbox->dev, "%s", of_node_full_name(node));
 490         dev_set_drvdata(&ipi_mbox->dev, ipi_mbox);
 491         ipi_mbox->dev.release = zynqmp_ipi_mbox_dev_release;
 492         ipi_mbox->dev.driver = &zynqmp_ipi_mbox_driver;
 493         ret = device_register(&ipi_mbox->dev);
 494         if (ret) {
 495                 dev_err(dev, "Failed to register ipi mbox dev.\n");
 496                 return ret;
 497         }
 498         mdev = &ipi_mbox->dev;
 499
 500         mchan = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
 501         name = "local_request_region";
 502         ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
 503         if (!ret) {
 504                 mchan->req_buf_size = resource_size(&res);
 505                 mchan->req_buf = devm_ioremap(mdev, res.start,
 506                                               mchan->req_buf_size);
 507                 if (!mchan->req_buf) {
 508                         dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
 509                         return -ENOMEM;
 510                 }
 511         } else if (ret != -ENODEV) {
 512                 dev_err(mdev, "Unmatched resource %s, %d.\n", name, ret);
 513                 return ret;
 514         }
 515
 516         name = "remote_response_region";
 517         ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
 518         if (!ret) {
 519                 mchan->resp_buf_size = resource_size(&res);
 520                 mchan->resp_buf = devm_ioremap(mdev, res.start,
 521                                                mchan->resp_buf_size);
 522                 if (!mchan->resp_buf) {
 523                         dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
 524                         return -ENOMEM;
 525                 }
 526         } else if (ret != -ENODEV) {
 527                 dev_err(mdev, "Unmatched resource %s.\n", name);
 528                 return ret;
 529         }
 530         mchan->rx_buf = devm_kzalloc(mdev,
 531                                      mchan->resp_buf_size +
 532                                      sizeof(struct zynqmp_ipi_message),
 533                                      GFP_KERNEL);
 534         if (!mchan->rx_buf)
 535                 return -ENOMEM;
 536
 537         mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
 538         name = "remote_request_region";
 539         ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
 540         if (!ret) {
 541                 mchan->req_buf_size = resource_size(&res);
 542                 mchan->req_buf = devm_ioremap(mdev, res.start,
 543                                               mchan->req_buf_size);
 544                 if (!mchan->req_buf) {
 545                         dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
 546                         return -ENOMEM;
 547                 }
 548         } else if (ret != -ENODEV) {
 549                 dev_err(mdev, "Unmatched resource %s.\n", name);
 550                 return ret;
 551         }
 552
 553         name = "local_response_region";
 554         ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
 555         if (!ret) {
 556                 mchan->resp_buf_size = resource_size(&res);
 557                 mchan->resp_buf = devm_ioremap(mdev, res.start,
 558                                                mchan->resp_buf_size);
 559                 if (!mchan->resp_buf) {
 560                         dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
 561                         return -ENOMEM;
 562                 }
 563         } else if (ret != -ENODEV) {
 564                 dev_err(mdev, "Unmatched resource %s.\n", name);
 565                 return ret;
 566         }
 567         mchan->rx_buf = devm_kzalloc(mdev,
 568                                      mchan->resp_buf_size +
 569                                      sizeof(struct zynqmp_ipi_message),
 570                                      GFP_KERNEL);
 571         if (!mchan->rx_buf)
 572                 return -ENOMEM;
 573
 574         /* Get the IPI remote agent ID */
 575         ret = of_property_read_u32(node, "xlnx,ipi-id", &ipi_mbox->remote_id);
 576         if (ret < 0) {
 577                 dev_err(dev, "No IPI remote ID is specified.\n");
 578                 return ret;
 579         }
 580
 581         mbox = &ipi_mbox->mbox;
 582         mbox->dev = mdev;
 583         mbox->ops = &zynqmp_ipi_chan_ops;
 584         mbox->num_chans = 2;
 585         mbox->txdone_irq = false;
 586         mbox->txdone_poll = true;
 587         mbox->txpoll_period = 5;
 588         mbox->of_xlate = zynqmp_ipi_of_xlate;
 589         chans = devm_kzalloc(mdev, 2 * sizeof(*chans), GFP_KERNEL);
 590         if (!chans)
 591                 return -ENOMEM;
 592         mbox->chans = chans;
 593         chans[IPI_MB_CHNL_TX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
 594         chans[IPI_MB_CHNL_RX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
 595         ipi_mbox->mchans[IPI_MB_CHNL_TX].chan_type = IPI_MB_CHNL_TX;
 596         ipi_mbox->mchans[IPI_MB_CHNL_RX].chan_type = IPI_MB_CHNL_RX;
 597         ret = devm_mbox_controller_register(mdev, mbox);
 598         if (ret)
 599                 dev_err(mdev,
 600                         "Failed to register mbox_controller(%d)\n", ret);
 601         else
 602                 dev_info(mdev,
 603                          "Registered ZynqMP IPI mbox with TX/RX channels.\n");
 604         return ret;
 605 }
 606
 607 /**
 608  * zynqmp_ipi_free_mboxes - Free IPI mailboxes devices
 609  *
 610  * @pdata: IPI private data
 611  */
 612 static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata)
 613 {
 614         struct zynqmp_ipi_mbox *ipi_mbox;
 615         int i;
 616
 617         i = pdata->num_mboxes;
 618         for (; i >= 0; i--) {
 619                 ipi_mbox = &pdata->ipi_mboxes[i];
 620                 if (ipi_mbox->dev.parent) {
 621                         mbox_controller_unregister(&ipi_mbox->mbox);
 622                         device_unregister(&ipi_mbox->dev);
 623                 }
 624         }
 625 }
 626
 627 static int zynqmp_ipi_probe(struct platform_device *pdev)
 628 {
 629         struct device *dev = &pdev->dev;
 630         struct device_node *nc, *np = pdev->dev.of_node;
 631         struct zynqmp_ipi_pdata *pdata;
 632         struct zynqmp_ipi_mbox *mbox;
 633         int num_mboxes, ret = -EINVAL;
 634
 635         num_mboxes = of_get_child_count(np);
 636         pdata = devm_kzalloc(dev, sizeof(*pdata) + (num_mboxes * sizeof(*mbox)),
 637                              GFP_KERNEL);
 638         if (!pdata)
 639                 return -ENOMEM;
 640         pdata->dev = dev;
 641
 642         /* Get the IPI local agents ID */
 643         ret = of_property_read_u32(np, "xlnx,ipi-id", &pdata->local_id);
 644         if (ret < 0) {
 645                 dev_err(dev, "No IPI local ID is specified.\n");
 646                 return ret;
 647         }
 648
 649         pdata->num_mboxes = num_mboxes;
 650         pdata->ipi_mboxes = (struct zynqmp_ipi_mbox *)
 651                             ((char *)pdata + sizeof(*pdata));
 652
 653         mbox = pdata->ipi_mboxes;
 654         for_each_available_child_of_node(np, nc) {
 655                 mbox->pdata = pdata;
 656                 ret = zynqmp_ipi_mbox_probe(mbox, nc);
 657                 if (ret) {
 658                         dev_err(dev, "failed to probe subdev.\n");
 659                         ret = -EINVAL;
 660                         goto free_mbox_dev;
 661                 }
 662                 mbox++;
 663         }
 664
 665         /* IPI IRQ */
 666         ret = platform_get_irq(pdev, 0);
 667         if (ret < 0) {
 668                 dev_err(dev, "unable to find IPI IRQ.\n");
 669                 goto free_mbox_dev;
 670         }
 671         pdata->irq = ret;
 672         ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt,
 673                                IRQF_SHARED, dev_name(dev), pdata);
 674         if (ret) {
 675                 dev_err(dev, "IRQ %d is not requested successfully.\n",
 676                         pdata->irq);
 677                 goto free_mbox_dev;
 678         }
 679
 680         platform_set_drvdata(pdev, pdata);
 681         return ret;
 682
 683 free_mbox_dev:
 684         zynqmp_ipi_free_mboxes(pdata);
 685         return ret;
 686 }
 687
 688 static int zynqmp_ipi_remove(struct platform_device *pdev)
 689 {
 690         struct zynqmp_ipi_pdata *pdata;
 691
 692         pdata = platform_get_drvdata(pdev);
 693         zynqmp_ipi_free_mboxes(pdata);
 694
 695         return 0;
 696 }
 697
 698 static struct platform_driver zynqmp_ipi_driver = {
 699         .probe = zynqmp_ipi_probe,
 700         .remove = zynqmp_ipi_remove,
 701         .driver = {
 702                    .name = "zynqmp-ipi",
 703                    .of_match_table = of_match_ptr(zynqmp_ipi_of_match),
 704         },
 705 };
 706
 707 static int __init zynqmp_ipi_init(void)
 708 {
 709         return platform_driver_register(&zynqmp_ipi_driver);
 710 }
 711 subsys_initcall(zynqmp_ipi_init);
 712
 713 static void __exit zynqmp_ipi_exit(void)
 714 {
 715         platform_driver_unregister(&zynqmp_ipi_driver);
 716 }
 717 module_exit(zynqmp_ipi_exit);
 718
 719 MODULE_LICENSE("GPL v2");
 720 MODULE_DESCRIPTION("Xilinx ZynqMP IPI Mailbox driver");
 721 MODULE_AUTHOR("Xilinx Inc.");