linux/drivers/mailbox/zynqmp-ipi-mailbox.c
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   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 */
  67struct 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 */
  88struct 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 */
 107struct 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
 116static struct device_driver zynqmp_ipi_mbox_driver = {
 117        .owner = THIS_MODULE,
 118        .name = "zynqmp-ipi-mbox",
 119};
 120
 121static 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 */
 146static 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 */
 187static 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 */
 227static 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 */
 265static 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 */
 316static 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 */
 358static 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 */
 387static 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 */
 403static 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
 421static const struct of_device_id zynqmp_ipi_of_match[] = {
 422        { .compatible = "xlnx,zynqmp-ipi-mailbox" },
 423        {},
 424};
 425MODULE_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 */
 436static 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 */
 460static 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 */
 473static 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 */
 612static 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
 627static 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                goto free_mbox_dev;
 669
 670        pdata->irq = ret;
 671        ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt,
 672                               IRQF_SHARED, dev_name(dev), pdata);
 673        if (ret) {
 674                dev_err(dev, "IRQ %d is not requested successfully.\n",
 675                        pdata->irq);
 676                goto free_mbox_dev;
 677        }
 678
 679        platform_set_drvdata(pdev, pdata);
 680        return ret;
 681
 682free_mbox_dev:
 683        zynqmp_ipi_free_mboxes(pdata);
 684        return ret;
 685}
 686
 687static int zynqmp_ipi_remove(struct platform_device *pdev)
 688{
 689        struct zynqmp_ipi_pdata *pdata;
 690
 691        pdata = platform_get_drvdata(pdev);
 692        zynqmp_ipi_free_mboxes(pdata);
 693
 694        return 0;
 695}
 696
 697static struct platform_driver zynqmp_ipi_driver = {
 698        .probe = zynqmp_ipi_probe,
 699        .remove = zynqmp_ipi_remove,
 700        .driver = {
 701                   .name = "zynqmp-ipi",
 702                   .of_match_table = of_match_ptr(zynqmp_ipi_of_match),
 703        },
 704};
 705
 706static int __init zynqmp_ipi_init(void)
 707{
 708        return platform_driver_register(&zynqmp_ipi_driver);
 709}
 710subsys_initcall(zynqmp_ipi_init);
 711
 712static void __exit zynqmp_ipi_exit(void)
 713{
 714        platform_driver_unregister(&zynqmp_ipi_driver);
 715}
 716module_exit(zynqmp_ipi_exit);
 717
 718MODULE_LICENSE("GPL v2");
 719MODULE_DESCRIPTION("Xilinx ZynqMP IPI Mailbox driver");
 720MODULE_AUTHOR("Xilinx Inc.");
 721