// SPDX-License-Identifier: GPL-2.0
/*
* Xilinx Inter Processor Interrupt(IPI) Mailbox Driver
*
* Copyright (C) 2018 Xilinx, Inc.
*/
#include <linux/arm-smccc.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mailbox_controller.h>
#include <linux/mailbox/zynqmp-ipi-message.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
/* IPI agent ID any */
#define IPI_ID_ANY 0xFFUL
/* indicate if ZynqMP IPI mailbox driver uses SMC calls or HVC calls */
#define USE_SMC 0
#define USE_HVC 1
/* Default IPI SMC function IDs */
#define SMC_IPI_MAILBOX_OPEN 0x82001000U
#define SMC_IPI_MAILBOX_RELEASE 0x82001001U
#define SMC_IPI_MAILBOX_STATUS_ENQUIRY 0x82001002U
#define SMC_IPI_MAILBOX_NOTIFY 0x82001003U
#define SMC_IPI_MAILBOX_ACK 0x82001004U
#define SMC_IPI_MAILBOX_ENABLE_IRQ 0x82001005U
#define SMC_IPI_MAILBOX_DISABLE_IRQ 0x82001006U
/* IPI SMC Macros */
#define IPI_SMC_ENQUIRY_DIRQ_MASK 0x00000001UL /* Flag to indicate if
* notification interrupt
* to be disabled.
*/
#define IPI_SMC_ACK_EIRQ_MASK 0x00000001UL /* Flag to indicate if
* notification interrupt
* to be enabled.
*/
/* IPI mailbox status */
#define IPI_MB_STATUS_IDLE 0
#define IPI_MB_STATUS_SEND_PENDING 1
#define IPI_MB_STATUS_RECV_PENDING 2
#define IPI_MB_CHNL_TX 0 /* IPI mailbox TX channel */
#define IPI_MB_CHNL_RX 1 /* IPI mailbox RX channel */
/**
* struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel
* @is_opened: indicate if the IPI channel is opened
* @req_buf: local to remote request buffer start address
* @resp_buf: local to remote response buffer start address
* @req_buf_size: request buffer size
* @resp_buf_size: response buffer size
* @rx_buf: receive buffer to pass received message to client
* @chan_type: channel type
*/
struct zynqmp_ipi_mchan {
int is_opened;
void __iomem *req_buf;
void __iomem *resp_buf;
void *rx_buf;
size_t req_buf_size;
size_t resp_buf_size;
unsigned int chan_type;
};
/**
* struct zynqmp_ipi_mbox - Description of a ZynqMP IPI mailbox
* platform data.
* @pdata: pointer to the IPI private data
* @dev: device pointer corresponding to the Xilinx ZynqMP
* IPI mailbox
* @remote_id: remote IPI agent ID
* @mbox: mailbox Controller
* @mchans: array for channels, tx channel and rx channel.
* @irq: IPI agent interrupt ID
*/
struct zynqmp_ipi_mbox {
struct zynqmp_ipi_pdata *pdata;
struct device dev;
u32 remote_id;
struct mbox_controller mbox;
struct zynqmp_ipi_mchan mchans[2];
};
/**
* struct zynqmp_ipi_pdata - Description of z ZynqMP IPI agent platform data.
*
* @dev: device pointer corresponding to the Xilinx ZynqMP
* IPI agent
* @irq: IPI agent interrupt ID
* @method: IPI SMC or HVC is going to be used
* @local_id: local IPI agent ID
* @num_mboxes: number of mailboxes of this IPI agent
* @ipi_mboxes: IPI mailboxes of this IPI agent
*/
struct zynqmp_ipi_pdata {
struct device *dev;
int irq;
unsigned int method;
u32 local_id;
int num_mboxes;
struct zynqmp_ipi_mbox ipi_mboxes[];
};
static struct device_driver zynqmp_ipi_mbox_driver = {
.owner = THIS_MODULE,
.name = "zynqmp-ipi-mbox",
};
static void zynqmp_ipi_fw_call(struct zynqmp_ipi_mbox *ipi_mbox,
unsigned long a0, unsigned long a3,
struct arm_smccc_res *res)
{
struct zynqmp_ipi_pdata *pdata = ipi_mbox->pdata;
unsigned long a1, a2;
a1 = pdata->local_id;
a2 = ipi_mbox->remote_id;
if (pdata->method == USE_SMC)
arm_smccc_smc(a0, a1, a2, a3, 0, 0, 0, 0, res);
else
arm_smccc_hvc(a0, a1, a2, a3, 0, 0, 0, 0, res);
}
/**
* zynqmp_ipi_interrupt - Interrupt handler for IPI notification
*
* @irq: Interrupt number
* @data: ZynqMP IPI mailbox platform data.
*
* Return: -EINVAL if there is no instance
* IRQ_NONE if the interrupt is not ours.
* IRQ_HANDLED if the rx interrupt was successfully handled.
*/
static irqreturn_t zynqmp_ipi_interrupt(int irq, void *data)
{
struct zynqmp_ipi_pdata *pdata = data;
struct mbox_chan *chan;
struct zynqmp_ipi_mbox *ipi_mbox;
struct zynqmp_ipi_mchan *mchan;
struct zynqmp_ipi_message *msg;
u64 arg0, arg3;
struct arm_smccc_res res;
int ret, i, status = IRQ_NONE;
(void)irq;
arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
arg3 = IPI_SMC_ENQUIRY_DIRQ_MASK;
for (i = 0; i < pdata->num_mboxes; i++) {
ipi_mbox = &pdata->ipi_mboxes[i];
mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
chan = &ipi_mbox->mbox.chans[IPI_MB_CHNL_RX];
zynqmp_ipi_fw_call(ipi_mbox, arg0, arg3, &res);
ret = (int)(res.a0 & 0xFFFFFFFF);
if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
if (mchan->is_opened) {
msg = mchan->rx_buf;
msg->len = mchan->req_buf_size;
memcpy_fromio(msg->data, mchan->req_buf,
msg->len);
mbox_chan_received_data(chan, (void *)msg);
status = IRQ_HANDLED;
}
}
}
return status;
}
/**
* zynqmp_ipi_peek_data - Peek to see if there are any rx messages.
*
* @chan: Channel Pointer
*
* Return: 'true' if there is pending rx data, 'false' if there is none.
*/
static bool zynqmp_ipi_peek_data(struct mbox_chan *chan)
{
struct device *dev = chan->mbox->dev;
struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
struct zynqmp_ipi_mchan *mchan = chan->con_priv;
int ret;
u64 arg0;
struct arm_smccc_res res;
if (WARN_ON(!ipi_mbox)) {
dev_err(dev, "no platform drv data??\n");
return false;
}
arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
ret = (int)(res.a0 & 0xFFFFFFFF);
if (mchan->chan_type == IPI_MB_CHNL_TX) {
/* TX channel, check if the message has been acked
* by the remote, if yes, response is available.
*/
if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
return false;
else
return true;
} else if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
/* RX channel, check if there is message arrived. */
return true;
}
return false;
}
/**
* zynqmp_ipi_last_tx_done - See if the last tx message is sent
*
* @chan: Channel pointer
*
* Return: 'true' is no pending tx data, 'false' if there are any.
*/
static bool zynqmp_ipi_last_tx_done(struct mbox_chan *chan)
{
struct device *dev = chan->mbox->dev;
struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
struct zynqmp_ipi_mchan *mchan = chan->con_priv;
int ret;
u64 arg0;
struct arm_smccc_res res;
if (WARN_ON(!ipi_mbox)) {
dev_err(dev, "no platform drv data??\n");
return false;
}
if (mchan->chan_type == IPI_MB_CHNL_TX) {
/* We only need to check if the message been taken
* by the remote in the TX channel
*/
arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
/* Check the SMC call status, a0 of the result */
ret = (int)(res.a0 & 0xFFFFFFFF);
if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
return false;
return true;
}
/* Always true for the response message in RX channel */
return true;
}
/**
* zynqmp_ipi_send_data - Send data
*
* @chan: Channel Pointer
* @data: Message Pointer
*
* Return: 0 if all goes good, else appropriate error messages.
*/
static int zynqmp_ipi_send_data(struct mbox_chan *chan, void *data)
{
struct device *dev = chan->mbox->dev;
struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
struct zynqmp_ipi_mchan *mchan = chan->con_priv;
struct zynqmp_ipi_message *msg = data;
u64 arg0;
struct arm_smccc_res res;
if (WARN_ON(!ipi_mbox)) {
dev_err(dev, "no platform drv data??\n");
return -EINVAL;
}
if (mchan->chan_type == IPI_MB_CHNL_TX) {
/* Send request message */
if (msg && msg->len > mchan->req_buf_size) {
dev_err(dev, "channel %d message length %u > max %lu\n",
mchan->chan_type, (unsigned int)msg->len,
mchan->req_buf_size);
return -EINVAL;
}
if (msg && msg->len)
memcpy_toio(mchan->req_buf, msg->data, msg->len);
/* Kick IPI mailbox to send message */
arg0 = SMC_IPI_MAILBOX_NOTIFY;
zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
} else {
/* Send response message */
if (msg && msg->len > mchan->resp_buf_size) {
dev_err(dev, "channel %d message length %u > max %lu\n",
mchan->chan_type, (unsigned int)msg->len,
mchan->resp_buf_size);
return -EINVAL;
}
if (msg && msg->len)
memcpy_toio(mchan->resp_buf, msg->data, msg->len);
arg0 = SMC_IPI_MAILBOX_ACK;
zynqmp_ipi_fw_call(ipi_mbox, arg0, IPI_SMC_ACK_EIRQ_MASK,
&res);
}
return 0;
}
/**
* zynqmp_ipi_startup - Startup the IPI channel
*
* @chan: Channel pointer
*
* Return: 0 if all goes good, else return corresponding error message
*/
static int zynqmp_ipi_startup(struct mbox_chan *chan)
{
struct device *dev = chan->mbox->dev;
struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
struct zynqmp_ipi_mchan *mchan = chan->con_priv;
u64 arg0;
struct arm_smccc_res res;
int ret = 0;
unsigned int nchan_type;
if (mchan->is_opened)
return 0;
/* If no channel has been opened, open the IPI mailbox */
nchan_type = (mchan->chan_type + 1) % 2;
if (!ipi_mbox->mchans[nchan_type].is_opened) {
arg0 = SMC_IPI_MAILBOX_OPEN;
zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
/* Check the SMC call status, a0 of the result */
ret = (int)(res.a0 & 0xFFFFFFFF);
if (ret < 0) {
dev_err(dev, "SMC to open the IPI channel failed.\n");
return ret;
}
ret = 0;
}
/* If it is RX channel, enable the IPI notification interrupt */
if (mchan->chan_type == IPI_MB_CHNL_RX) {
arg0 = SMC_IPI_MAILBOX_ENABLE_IRQ;
zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
}
mchan->is_opened = 1;
return ret;
}
/**
* zynqmp_ipi_shutdown - Shutdown the IPI channel
*
* @chan: Channel pointer
*/
static void zynqmp_ipi_shutdown(struct mbox_chan *chan)
{
struct device *dev = chan->mbox->dev;
struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
struct zynqmp_ipi_mchan *mchan = chan->con_priv;
u64 arg0;
struct arm_smccc_res res;
unsigned int chan_type;
if (!mchan->is_opened)
return;
/* If it is RX channel, disable notification interrupt */
chan_type = mchan->chan_type;
if (chan_type == IPI_MB_CHNL_RX) {
arg0 = SMC_IPI_MAILBOX_DISABLE_IRQ;
zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
}
/* Release IPI mailbox if no other channel is opened */
chan_type = (chan_type + 1) % 2;
if (!ipi_mbox->mchans[chan_type].is_opened) {
arg0 = SMC_IPI_MAILBOX_RELEASE;
zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
}
mchan->is_opened = 0;
}
/* ZynqMP IPI mailbox operations */
static const struct mbox_chan_ops zynqmp_ipi_chan_ops = {
.startup = zynqmp_ipi_startup,
.shutdown = zynqmp_ipi_shutdown,
.peek_data = zynqmp_ipi_peek_data,
.last_tx_done = zynqmp_ipi_last_tx_done,
.send_data = zynqmp_ipi_send_data,
};
/**
* zynqmp_ipi_of_xlate - Translate of phandle to IPI mailbox channel
*
* @mbox: mailbox controller pointer
* @p: phandle pointer
*
* Return: Mailbox channel, else return error pointer.
*/
static struct mbox_chan *zynqmp_ipi_of_xlate(struct mbox_controller *mbox,
const struct of_phandle_args *p)
{
struct mbox_chan *chan;
struct device *dev = mbox->dev;
unsigned int chan_type;
/* Only supports TX and RX channels */
chan_type = p->args[0];
if (chan_type != IPI_MB_CHNL_TX && chan_type != IPI_MB_CHNL_RX) {
dev_err(dev, "req chnl failure: invalid chnl type %u.\n",
chan_type);
return ERR_PTR(-EINVAL);
}
chan = &mbox->chans[chan_type];
return chan;
}
static const struct of_device_id zynqmp_ipi_of_match[] = {
{ .compatible = "xlnx,zynqmp-ipi-mailbox" },
{},
};
MODULE_DEVICE_TABLE(of, zynqmp_ipi_of_match);
/**
* zynqmp_ipi_mbox_get_buf_res - Get buffer resource from the IPI dev node
*
* @node: IPI mbox device child node
* @name: name of the IPI buffer
* @res: pointer to where the resource information will be stored.
*
* Return: 0 for success, negative value for failure
*/
static int zynqmp_ipi_mbox_get_buf_res(struct device_node *node,
const char *name,
struct resource *res)
{
int ret, index;
index = of_property_match_string(node, "reg-names", name);
if (index >= 0) {
ret = of_address_to_resource(node, index, res);
if (ret < 0)
return -EINVAL;
return 0;
}
return -ENODEV;
}
/**
* zynqmp_ipi_mbox_dev_release() - release the existence of a ipi mbox dev
*
* @dev: the ipi mailbox device
*
* This is to avoid the no device release() function kernel warning.
*
*/
static void zynqmp_ipi_mbox_dev_release(struct device *dev)
{
(void)dev;
}
/**
* zynqmp_ipi_mbox_probe - probe IPI mailbox resource from device node
*
* @ipi_mbox: pointer to IPI mailbox private data structure
* @node: IPI mailbox device node
*
* Return: 0 for success, negative value for failure
*/
static int zynqmp_ipi_mbox_probe(struct zynqmp_ipi_mbox *ipi_mbox,
struct device_node *node)
{
struct zynqmp_ipi_mchan *mchan;
struct mbox_chan *chans;
struct mbox_controller *mbox;
struct resource res;
struct device *dev, *mdev;
const char *name;
int ret;
dev = ipi_mbox->pdata->dev;
/* Initialize dev for IPI mailbox */
ipi_mbox->dev.parent = dev;
ipi_mbox->dev.release = NULL;
ipi_mbox->dev.of_node = node;
dev_set_name(&ipi_mbox->dev, "%s", of_node_full_name(node));
dev_set_drvdata(&ipi_mbox->dev, ipi_mbox);
ipi_mbox->dev.release = zynqmp_ipi_mbox_dev_release;
ipi_mbox->dev.driver = &zynqmp_ipi_mbox_driver;
ret = device_register(&ipi_mbox->dev);
if (ret) {
dev_err(dev, "Failed to register ipi mbox dev.\n");
put_device(&ipi_mbox->dev);
return ret;
}
mdev = &ipi_mbox->dev;
mchan = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
name = "local_request_region";
ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
if (!ret) {
mchan->req_buf_size = resource_size(&res);
mchan->req_buf = devm_ioremap(mdev, res.start,
mchan->req_buf_size);
if (!mchan->req_buf) {
dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
return -ENOMEM;
}
} else if (ret != -ENODEV) {
dev_err(mdev, "Unmatched resource %s, %d.\n", name, ret);
return ret;
}
name = "remote_response_region";
ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
if (!ret) {
mchan->resp_buf_size = resource_size(&res);
mchan->resp_buf = devm_ioremap(mdev, res.start,
mchan->resp_buf_size);
if (!mchan->resp_buf) {
dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
return -ENOMEM;
}
} else if (ret != -ENODEV) {
dev_err(mdev, "Unmatched resource %s.\n", name);
return ret;
}
mchan->rx_buf = devm_kzalloc(mdev,
mchan->resp_buf_size +
sizeof(struct zynqmp_ipi_message),
GFP_KERNEL);
if (!mchan->rx_buf)
return -ENOMEM;
mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
name = "remote_request_region";
ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
if (!ret) {
mchan->req_buf_size = resource_size(&res);
mchan->req_buf = devm_ioremap(mdev, res.start,
mchan->req_buf_size);
if (!mchan->req_buf) {
dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
return -ENOMEM;
}
} else if (ret != -ENODEV) {
dev_err(mdev, "Unmatched resource %s.\n", name);
return ret;
}
name = "local_response_region";
ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
if (!ret) {
mchan->resp_buf_size = resource_size(&res);
mchan->resp_buf = devm_ioremap(mdev, res.start,
mchan->resp_buf_size);
if (!mchan->resp_buf) {
dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
return -ENOMEM;
}
} else if (ret != -ENODEV) {
dev_err(mdev, "Unmatched resource %s.\n", name);
return ret;
}
mchan->rx_buf = devm_kzalloc(mdev,
mchan->resp_buf_size +
sizeof(struct zynqmp_ipi_message),
GFP_KERNEL);
if (!mchan->rx_buf)
return -ENOMEM;
/* Get the IPI remote agent ID */
ret = of_property_read_u32(node, "xlnx,ipi-id", &ipi_mbox->remote_id);
if (ret < 0) {
dev_err(dev, "No IPI remote ID is specified.\n");
return ret;
}
mbox = &ipi_mbox->mbox;
mbox->dev = mdev;
mbox->ops = &zynqmp_ipi_chan_ops;
mbox->num_chans = 2;
mbox->txdone_irq = false;
mbox->txdone_poll = true;
mbox->txpoll_period = 5;
mbox->of_xlate = zynqmp_ipi_of_xlate;
chans = devm_kzalloc(mdev, 2 * sizeof(*chans), GFP_KERNEL);
if (!chans)
return -ENOMEM;
mbox->chans = chans;
chans[IPI_MB_CHNL_TX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
chans[IPI_MB_CHNL_RX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
ipi_mbox->mchans[IPI_MB_CHNL_TX].chan_type = IPI_MB_CHNL_TX;
ipi_mbox->mchans[IPI_MB_CHNL_RX].chan_type = IPI_MB_CHNL_RX;
ret = devm_mbox_controller_register(mdev, mbox);
if (ret)
dev_err(mdev,
"Failed to register mbox_controller(%d)\n", ret);
else
dev_info(mdev,
"Registered ZynqMP IPI mbox with TX/RX channels.\n");
return ret;
}
/**
* zynqmp_ipi_free_mboxes - Free IPI mailboxes devices
*
* @pdata: IPI private data
*/
static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata)
{
struct zynqmp_ipi_mbox *ipi_mbox;
int i;
i = pdata->num_mboxes;
for (; i >= 0; i--) {
ipi_mbox = &pdata->ipi_mboxes[i];
if (ipi_mbox->dev.parent) {
mbox_controller_unregister(&ipi_mbox->mbox);
if (device_is_registered(&ipi_mbox->dev))
device_unregister(&ipi_mbox->dev);
}
}
}
static int zynqmp_ipi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *nc, *np = pdev->dev.of_node;
struct zynqmp_ipi_pdata *pdata;
struct zynqmp_ipi_mbox *mbox;
int num_mboxes, ret = -EINVAL;
num_mboxes = of_get_available_child_count(np);
if (num_mboxes == 0) {
dev_err(dev, "mailbox nodes not available\n");
return -EINVAL;
}
pdata = devm_kzalloc(dev, struct_size(pdata, ipi_mboxes, num_mboxes),
GFP_KERNEL);
if (!pdata)
return -ENOMEM;
pdata->dev = dev;
/* Get the IPI local agents ID */
ret = of_property_read_u32(np, "xlnx,ipi-id", &pdata->local_id);
if (ret < 0) {
dev_err(dev, "No IPI local ID is specified.\n");
return ret;
}
pdata->num_mboxes = num_mboxes;
mbox = pdata->ipi_mboxes;
for_each_available_child_of_node(np, nc) {
mbox->pdata = pdata;
ret = zynqmp_ipi_mbox_probe(mbox, nc);
if (ret) {
of_node_put(nc);
dev_err(dev, "failed to probe subdev.\n");
ret = -EINVAL;
goto free_mbox_dev;
}
mbox++;
}
/* IPI IRQ */
ret = platform_get_irq(pdev, 0);
if (ret < 0)
goto free_mbox_dev;
pdata->irq = ret;
ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt,
IRQF_SHARED, dev_name(dev), pdata);
if (ret) {
dev_err(dev, "IRQ %d is not requested successfully.\n",
pdata->irq);
goto free_mbox_dev;
}
platform_set_drvdata(pdev, pdata);
return ret;
free_mbox_dev:
zynqmp_ipi_free_mboxes(pdata);
return ret;
}
static int zynqmp_ipi_remove(struct platform_device *pdev)
{
struct zynqmp_ipi_pdata *pdata;
pdata = platform_get_drvdata(pdev);
zynqmp_ipi_free_mboxes(pdata);
return 0;
}
static struct platform_driver zynqmp_ipi_driver = {
.probe = zynqmp_ipi_probe,
.remove = zynqmp_ipi_remove,
.driver = {
.name = "zynqmp-ipi",
.of_match_table = of_match_ptr(zynqmp_ipi_of_match),
},
};
static int __init zynqmp_ipi_init(void)
{
return platform_driver_register(&zynqmp_ipi_driver);
}
subsys_initcall(zynqmp_ipi_init);
static void __exit zynqmp_ipi_exit(void)
{
platform_driver_unregister(&zynqmp_ipi_driver);
}
module_exit(zynqmp_ipi_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Xilinx ZynqMP IPI Mailbox driver");
MODULE_AUTHOR("Xilinx Inc.");