net/qrtr/fifo.c - kernel/msm - Git at Google

 /*
  * Copyright (c) 2016, Linaro Ltd
  * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
  * only version 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/of_device.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/sched.h>
 #include <microvisor/microvisor.h>

 #include "qrtr.h"

 #define FIFO_MAGIC_KEY 0x24495043 /* "$IPC" */
 #define FIFO_SIZE 0x4000
 #define FIFO_0_START 0x1000
 #define FIFO_1_START (FIFO_0_START + FIFO_SIZE)
 #define FIFO_MAGIC_IDX 0x0
 #define TAIL_0_IDX 0x1
 #define HEAD_0_IDX 0x2
 #define TAIL_1_IDX 0x3
 #define HEAD_1_IDX 0x4

 struct fifo_pipe {
 	__le32 *tail;
 	__le32 *head;

 	void *fifo;
 	size_t length;
 };

 /**
  * qrtr_fifo_xprt - qrtr FIFO transport structure
  * @ep: qrtr endpoint specific info.
  * @tx_pipe: TX FIFO specific info.
  * @rx_pipe: RX FIFO specific info.
  * @fifo_base: Base of the shared FIFO.
  * @fifo_size: FIFO Size.
  * @tx_fifo_idx: TX FIFO index.
  * @kcap: Register info to raise irq to other VM.
  */
 struct qrtr_fifo_xprt {
 	struct qrtr_endpoint ep;
 	struct fifo_pipe tx_pipe;
 	struct fifo_pipe rx_pipe;
 	void *fifo_base;
 	size_t fifo_size;
 	int tx_fifo_idx;
 	okl4_kcap_t kcap;
 };

 static void qrtr_fifo_raise_virq(struct qrtr_fifo_xprt *xprtp);

 static size_t fifo_rx_avail(struct fifo_pipe *pipe)
 {
 	u32 head;
 	u32 tail;

 	head = le32_to_cpu(*pipe->head);
 	tail = le32_to_cpu(*pipe->tail);

 	if (head < tail)
 		return pipe->length - tail + head;

 	return head - tail;
 }

 static void fifo_rx_peak(struct fifo_pipe *pipe,
 			 void *data, unsigned int offset, size_t count)
 {
 	size_t len;
 	u32 tail;

 	tail = le32_to_cpu(*pipe->tail);
 	tail += offset;
 	if (tail >= pipe->length)
 		tail -= pipe->length;

 	len = min_t(size_t, count, pipe->length - tail);
 	if (len)
 		memcpy_fromio(data, pipe->fifo + tail, len);

 	if (len != count)
 		memcpy_fromio(data + len, pipe->fifo, (count - len));
 }

 static void fifo_rx_advance(struct fifo_pipe *pipe, size_t count)
 {
 	u32 tail;

 	tail = le32_to_cpu(*pipe->tail);

 	tail += count;
 	if (tail > pipe->length)
 		tail -= pipe->length;

 	*pipe->tail = cpu_to_le32(tail);
 }

 static size_t fifo_tx_avail(struct fifo_pipe *pipe)
 {
 	u32 head;
 	u32 tail;
 	u32 avail;

 	 head = le32_to_cpu(*pipe->head);
 	 tail = le32_to_cpu(*pipe->tail);

 	if (tail <= head)
 		avail = pipe->length - head + tail;
 	else
 		avail = tail - head;

 	return avail;
 }

 static void fifo_tx_write(struct fifo_pipe *pipe,
 			  const void *data, size_t count)
 {
 	size_t len;
 	u32 head;

 	head = le32_to_cpu(*pipe->head);

 	len = min_t(size_t, count, pipe->length - head);
 	if (len)
 		memcpy_toio(pipe->fifo + head, data, len);

 	if (len != count)
 		memcpy_toio(pipe->fifo, data + len, count - len);

 	head += count;
 	if (head >= pipe->length)
 		head -= pipe->length;

 	/* Ensure ordering of fifo and head update */
 	wmb();

 	*pipe->head = cpu_to_le32(head);
 }

 /* from qrtr to FIFO */
 static int xprt_write(struct qrtr_endpoint *ep, struct sk_buff *skb)
 {
 	struct qrtr_fifo_xprt *xprtp;
 	int rc;

 	xprtp = container_of(ep, struct qrtr_fifo_xprt, ep);

 	rc = skb_linearize(skb);
 	if (rc) {
 		kfree_skb(skb);
 		return rc;
 	}

 	/* TODO: FIFO write : check if we can write full packet at one shot */
 	if (fifo_tx_avail(&xprtp->tx_pipe) < skb->len) {
 		pr_err("No Space in FIFO\n");
 		return -EAGAIN;
 	}

 	fifo_tx_write(&xprtp->tx_pipe, skb->data, skb->len);
 	kfree_skb(skb);

 	qrtr_fifo_raise_virq(xprtp);

 	return 0;
 }

 static void xprt_read_data(struct qrtr_fifo_xprt *xprtp)
 {
 	int rc;
 	u32 hdr[8];
 	void *data;
 	size_t pkt_len;
 	size_t rx_avail;
 	size_t hdr_len = sizeof(hdr);

 	while (fifo_rx_avail(&xprtp->rx_pipe)) {
 		fifo_rx_peak(&xprtp->rx_pipe, &hdr, 0, hdr_len);
 		pkt_len = qrtr_peek_pkt_size((void *)&hdr);

 		if (pkt_len < 0) {
 			pr_err("%s invalid pkt_len %zu\n", __func__, pkt_len);
 			break;
 		}

 		data = kzalloc(pkt_len, GFP_ATOMIC);
 		if (!data)
 			break;

 		rx_avail = fifo_rx_avail(&xprtp->rx_pipe);
 		if (rx_avail < pkt_len) {
 			pr_err("%s Not FULL pkt in FIFO %zu %zu\n",
 			       __func__, rx_avail, pkt_len);
 			break;
 		}

 		fifo_rx_peak(&xprtp->rx_pipe, data, 0, pkt_len);
 		fifo_rx_advance(&xprtp->rx_pipe, pkt_len);

 		rc = qrtr_endpoint_post(&xprtp->ep, data, pkt_len);
 		if (rc == -EINVAL)
 			pr_err("%s invalid ipcrouter packet\n", __func__);
 		kfree(data);
 		data = NULL;
 	}
 }

 static void qrtr_fifo_raise_virq(struct qrtr_fifo_xprt *xprtp)
 {
 	okl4_error_t err;
 	unsigned long payload = 0xffff;

 	err = _okl4_sys_vinterrupt_raise(xprtp->kcap, payload);
 }

 static irqreturn_t qrtr_fifo_virq_handler(int irq, void *dev_id)
 {
 	xprt_read_data((struct qrtr_fifo_xprt *)dev_id);
 	return IRQ_HANDLED;
 }

 /**
  * qrtr_fifo_config_init() - init FIFO xprt configs
  *
  * @return: 0 on success, standard Linux error codes on error.
  *
  * This function is called to initialize the FIFO XPRT pointer with
  * the FIFO XPRT configurations either from device tree or static arrays.
  */
 static int qrtr_fifo_config_init(struct qrtr_fifo_xprt *xprtp)
 {
 	__le32 *descs;

 	descs = xprtp->fifo_base;
 	descs[FIFO_MAGIC_IDX] = FIFO_MAGIC_KEY;

 	if (xprtp->tx_fifo_idx) {
 		xprtp->tx_pipe.tail = &descs[TAIL_0_IDX];
 		xprtp->tx_pipe.head = &descs[HEAD_0_IDX];
 		xprtp->tx_pipe.fifo = xprtp->fifo_base + FIFO_0_START;
 		xprtp->tx_pipe.length = FIFO_SIZE;

 		xprtp->rx_pipe.tail = &descs[TAIL_1_IDX];
 		xprtp->rx_pipe.head = &descs[HEAD_1_IDX];
 		xprtp->rx_pipe.fifo = xprtp->fifo_base + FIFO_1_START;
 		xprtp->rx_pipe.length = FIFO_SIZE;
 	} else {
 		xprtp->tx_pipe.tail = &descs[TAIL_1_IDX];
 		xprtp->tx_pipe.head = &descs[HEAD_1_IDX];
 		xprtp->tx_pipe.fifo = xprtp->fifo_base + FIFO_1_START;
 		xprtp->tx_pipe.length = FIFO_SIZE;

 		xprtp->rx_pipe.tail = &descs[TAIL_0_IDX];
 		xprtp->rx_pipe.head = &descs[HEAD_0_IDX];
 		xprtp->rx_pipe.fifo = xprtp->fifo_base + FIFO_0_START;
 		xprtp->rx_pipe.length = FIFO_SIZE;
 	}

 	/* Reset respective index */
 	*xprtp->tx_pipe.head = 0;
 	*xprtp->rx_pipe.tail = 0;

 	return 0;
 }

 /**
  * qrtr_fifo_xprt_probe() - Probe an FIFO xprt
  *
  * @pdev: Platform device corresponding to FIFO xprt.
  *
  * @return: 0 on success, standard Linux error codes on error.
  *
  * This function is called when the underlying device tree driver registers
  * a platform device, mapped to an FIFO transport.
  */
 static int qrtr_fifo_xprt_probe(struct platform_device *pdev)
 {
 	int irq;
 	int ret;
 	struct resource *r;
 	struct device *parent;
 	struct qrtr_fifo_xprt *xprtp;
 	struct device_node *ipc_irq_np;
 	struct device_node *ipc_shm_np;
 	struct platform_device *ipc_shm_dev;

 	xprtp = devm_kzalloc(&pdev->dev, sizeof(*xprtp), GFP_KERNEL);
 	if (!xprtp)
 		return -ENOMEM;

 	parent = &pdev->dev;
 	ipc_irq_np = parent->of_node;

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return -ENODEV;

 	ret = devm_request_irq(parent, irq, qrtr_fifo_virq_handler,
 			       IRQF_TRIGGER_RISING, dev_name(parent),
 			       xprtp);
 	if (ret < 0)
 		return -ENODEV;

 	/* this kcap is required to raise VIRQ */
 	ret = of_property_read_u32(ipc_irq_np, "reg", &xprtp->kcap);
 	if (ret < 0)
 		return -ENODEV;

 	ipc_shm_np = of_parse_phandle(ipc_irq_np, "qcom,ipc-shm", 0);
 	if (!ipc_shm_np)
 		return -ENODEV;

 	ipc_shm_dev = of_find_device_by_node(ipc_shm_np);
 	if (!ipc_shm_dev)
 		return -ENODEV;

 	r = platform_get_resource(ipc_shm_dev, IORESOURCE_MEM, 0);
 	if (!r) {
 		pr_err("%s failed to get shared FIFO\n", __func__);
 		return -ENODEV;
 	}

 	xprtp->tx_fifo_idx = of_property_read_bool(ipc_shm_np,
 						   "qcom,tx-is-first");

 	xprtp->fifo_size = resource_size(r);
 	xprtp->fifo_base = devm_ioremap_nocache(&pdev->dev, r->start,
 						resource_size(r));
 	if (!xprtp->fifo_base) {
 		pr_err("%s ioreamp_nocache() failed\n", __func__);
 		return -ENOMEM;
 	}

 	ret = qrtr_fifo_config_init(xprtp);
 	if (ret) {
 		pr_err("%s init failed ret[%d]\n", __func__, ret);
 		return ret;
 	}

 	xprtp->ep.xmit = xprt_write;
 	ret = qrtr_endpoint_register(&xprtp->ep, QRTR_EP_NID_AUTO, false);
 	if (ret)
 		return ret;

 	if (fifo_rx_avail(&xprtp->rx_pipe))
 		xprt_read_data(xprtp);

 	return 0;
 }

 static const struct of_device_id qrtr_fifo_xprt_match_table[] = {
 	{ .compatible = "qcom,ipcr-fifo-xprt" },
 	{},
 };

 static struct platform_driver qrtr_fifo_xprt_driver = {
 	.probe = qrtr_fifo_xprt_probe,
 	.driver = {
 		.name = "qcom_fifo_qrtr",
 		.owner = THIS_MODULE,
 		.of_match_table = qrtr_fifo_xprt_match_table,
 	 },
 };

 static int __init qrtr_fifo_xprt_init(void)
 {
 	int rc;

 	rc = platform_driver_register(&qrtr_fifo_xprt_driver);
 	if (rc) {
 		pr_err("%s: driver register failed %d\n", __func__, rc);
 		return rc;
 	}

 	return 0;
 }

 module_init(qrtr_fifo_xprt_init);
 MODULE_DESCRIPTION("QTI IPC-router FIFO XPRT");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (c) 2016, Linaro Ltd
	* Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 and
	* only version 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/delay.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/of_device.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/types.h>
	#include <linux/skbuff.h>
	#include <linux/sched.h>
	#include <microvisor/microvisor.h>

	#include "qrtr.h"

	#define FIFO_MAGIC_KEY 0x24495043 /* "$IPC" */
	#define FIFO_SIZE 0x4000
	#define FIFO_0_START 0x1000
	#define FIFO_1_START (FIFO_0_START + FIFO_SIZE)
	#define FIFO_MAGIC_IDX 0x0
	#define TAIL_0_IDX 0x1
	#define HEAD_0_IDX 0x2
	#define TAIL_1_IDX 0x3
	#define HEAD_1_IDX 0x4

	struct fifo_pipe {
	__le32 *tail;
	__le32 *head;

	void *fifo;
	size_t length;
	};

	/**
	* qrtr_fifo_xprt - qrtr FIFO transport structure
	* @ep: qrtr endpoint specific info.
	* @tx_pipe: TX FIFO specific info.
	* @rx_pipe: RX FIFO specific info.
	* @fifo_base: Base of the shared FIFO.
	* @fifo_size: FIFO Size.
	* @tx_fifo_idx: TX FIFO index.
	* @kcap: Register info to raise irq to other VM.
	*/
	struct qrtr_fifo_xprt {
	struct qrtr_endpoint ep;
	struct fifo_pipe tx_pipe;
	struct fifo_pipe rx_pipe;
	void *fifo_base;
	size_t fifo_size;
	int tx_fifo_idx;
	okl4_kcap_t kcap;
	};

	static void qrtr_fifo_raise_virq(struct qrtr_fifo_xprt *xprtp);

	static size_t fifo_rx_avail(struct fifo_pipe *pipe)
	{
	u32 head;
	u32 tail;

	head = le32_to_cpu(*pipe->head);
	tail = le32_to_cpu(*pipe->tail);

	if (head < tail)
	return pipe->length - tail + head;

	return head - tail;
	}

	static void fifo_rx_peak(struct fifo_pipe *pipe,
	void *data, unsigned int offset, size_t count)
	{
	size_t len;
	u32 tail;

	tail = le32_to_cpu(*pipe->tail);
	tail += offset;
	if (tail >= pipe->length)
	tail -= pipe->length;

	len = min_t(size_t, count, pipe->length - tail);
	if (len)
	memcpy_fromio(data, pipe->fifo + tail, len);

	if (len != count)
	memcpy_fromio(data + len, pipe->fifo, (count - len));
	}

	static void fifo_rx_advance(struct fifo_pipe *pipe, size_t count)
	{
	u32 tail;

	tail = le32_to_cpu(*pipe->tail);

	tail += count;
	if (tail > pipe->length)
	tail -= pipe->length;

	*pipe->tail = cpu_to_le32(tail);
	}

	static size_t fifo_tx_avail(struct fifo_pipe *pipe)
	{
	u32 head;
	u32 tail;
	u32 avail;

	head = le32_to_cpu(*pipe->head);
	tail = le32_to_cpu(*pipe->tail);

	if (tail <= head)
	avail = pipe->length - head + tail;
	else
	avail = tail - head;

	return avail;
	}

	static void fifo_tx_write(struct fifo_pipe *pipe,
	const void *data, size_t count)
	{
	size_t len;
	u32 head;

	head = le32_to_cpu(*pipe->head);

	len = min_t(size_t, count, pipe->length - head);
	if (len)
	memcpy_toio(pipe->fifo + head, data, len);

	if (len != count)
	memcpy_toio(pipe->fifo, data + len, count - len);

	head += count;
	if (head >= pipe->length)
	head -= pipe->length;

	/* Ensure ordering of fifo and head update */
	wmb();

	*pipe->head = cpu_to_le32(head);
	}

	/* from qrtr to FIFO */
	static int xprt_write(struct qrtr_endpoint ep, struct sk_buff skb)
	{
	struct qrtr_fifo_xprt *xprtp;
	int rc;

	xprtp = container_of(ep, struct qrtr_fifo_xprt, ep);

	rc = skb_linearize(skb);
	if (rc) {
	kfree_skb(skb);
	return rc;
	}

	/* TODO: FIFO write : check if we can write full packet at one shot */
	if (fifo_tx_avail(&xprtp->tx_pipe) < skb->len) {
	pr_err("No Space in FIFO\n");
	return -EAGAIN;
	}

	fifo_tx_write(&xprtp->tx_pipe, skb->data, skb->len);
	kfree_skb(skb);

	qrtr_fifo_raise_virq(xprtp);

	return 0;
	}

	static void xprt_read_data(struct qrtr_fifo_xprt *xprtp)
	{
	int rc;
	u32 hdr[8];
	void *data;
	size_t pkt_len;
	size_t rx_avail;
	size_t hdr_len = sizeof(hdr);

	while (fifo_rx_avail(&xprtp->rx_pipe)) {
	fifo_rx_peak(&xprtp->rx_pipe, &hdr, 0, hdr_len);
	pkt_len = qrtr_peek_pkt_size((void *)&hdr);

	if (pkt_len < 0) {
	pr_err("%s invalid pkt_len %zu\n", __func__, pkt_len);
	break;
	}

	data = kzalloc(pkt_len, GFP_ATOMIC);
	if (!data)
	break;

	rx_avail = fifo_rx_avail(&xprtp->rx_pipe);
	if (rx_avail < pkt_len) {
	pr_err("%s Not FULL pkt in FIFO %zu %zu\n",
	__func__, rx_avail, pkt_len);
	break;
	}

	fifo_rx_peak(&xprtp->rx_pipe, data, 0, pkt_len);
	fifo_rx_advance(&xprtp->rx_pipe, pkt_len);

	rc = qrtr_endpoint_post(&xprtp->ep, data, pkt_len);
	if (rc == -EINVAL)
	pr_err("%s invalid ipcrouter packet\n", __func__);
	kfree(data);
	data = NULL;
	}
	}

	static void qrtr_fifo_raise_virq(struct qrtr_fifo_xprt *xprtp)
	{
	okl4_error_t err;
	unsigned long payload = 0xffff;

	err = _okl4_sys_vinterrupt_raise(xprtp->kcap, payload);
	}

	static irqreturn_t qrtr_fifo_virq_handler(int irq, void *dev_id)
	{
	xprt_read_data((struct qrtr_fifo_xprt *)dev_id);
	return IRQ_HANDLED;
	}

	/**
	* qrtr_fifo_config_init() - init FIFO xprt configs
	*
	* @return: 0 on success, standard Linux error codes on error.
	*
	* This function is called to initialize the FIFO XPRT pointer with
	* the FIFO XPRT configurations either from device tree or static arrays.
	*/
	static int qrtr_fifo_config_init(struct qrtr_fifo_xprt *xprtp)
	{
	__le32 *descs;

	descs = xprtp->fifo_base;
	descs[FIFO_MAGIC_IDX] = FIFO_MAGIC_KEY;

	if (xprtp->tx_fifo_idx) {
	xprtp->tx_pipe.tail = &descs[TAIL_0_IDX];
	xprtp->tx_pipe.head = &descs[HEAD_0_IDX];
	xprtp->tx_pipe.fifo = xprtp->fifo_base + FIFO_0_START;
	xprtp->tx_pipe.length = FIFO_SIZE;

	xprtp->rx_pipe.tail = &descs[TAIL_1_IDX];
	xprtp->rx_pipe.head = &descs[HEAD_1_IDX];
	xprtp->rx_pipe.fifo = xprtp->fifo_base + FIFO_1_START;
	xprtp->rx_pipe.length = FIFO_SIZE;
	} else {
	xprtp->tx_pipe.tail = &descs[TAIL_1_IDX];
	xprtp->tx_pipe.head = &descs[HEAD_1_IDX];
	xprtp->tx_pipe.fifo = xprtp->fifo_base + FIFO_1_START;
	xprtp->tx_pipe.length = FIFO_SIZE;

	xprtp->rx_pipe.tail = &descs[TAIL_0_IDX];
	xprtp->rx_pipe.head = &descs[HEAD_0_IDX];
	xprtp->rx_pipe.fifo = xprtp->fifo_base + FIFO_0_START;
	xprtp->rx_pipe.length = FIFO_SIZE;
	}

	/* Reset respective index */
	*xprtp->tx_pipe.head = 0;
	*xprtp->rx_pipe.tail = 0;

	return 0;
	}

	/**
	* qrtr_fifo_xprt_probe() - Probe an FIFO xprt
	*
	* @pdev: Platform device corresponding to FIFO xprt.
	*
	* @return: 0 on success, standard Linux error codes on error.
	*
	* This function is called when the underlying device tree driver registers
	* a platform device, mapped to an FIFO transport.
	*/
	static int qrtr_fifo_xprt_probe(struct platform_device *pdev)
	{
	int irq;
	int ret;
	struct resource *r;
	struct device *parent;
	struct qrtr_fifo_xprt *xprtp;
	struct device_node *ipc_irq_np;
	struct device_node *ipc_shm_np;
	struct platform_device *ipc_shm_dev;

	xprtp = devm_kzalloc(&pdev->dev, sizeof(*xprtp), GFP_KERNEL);
	if (!xprtp)
	return -ENOMEM;

	parent = &pdev->dev;
	ipc_irq_np = parent->of_node;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return -ENODEV;

	ret = devm_request_irq(parent, irq, qrtr_fifo_virq_handler,
	IRQF_TRIGGER_RISING, dev_name(parent),
	xprtp);
	if (ret < 0)
	return -ENODEV;

	/* this kcap is required to raise VIRQ */
	ret = of_property_read_u32(ipc_irq_np, "reg", &xprtp->kcap);
	if (ret < 0)
	return -ENODEV;

	ipc_shm_np = of_parse_phandle(ipc_irq_np, "qcom,ipc-shm", 0);
	if (!ipc_shm_np)
	return -ENODEV;

	ipc_shm_dev = of_find_device_by_node(ipc_shm_np);
	if (!ipc_shm_dev)
	return -ENODEV;

	r = platform_get_resource(ipc_shm_dev, IORESOURCE_MEM, 0);
	if (!r) {
	pr_err("%s failed to get shared FIFO\n", __func__);
	return -ENODEV;
	}

	xprtp->tx_fifo_idx = of_property_read_bool(ipc_shm_np,
	"qcom,tx-is-first");

	xprtp->fifo_size = resource_size(r);
	xprtp->fifo_base = devm_ioremap_nocache(&pdev->dev, r->start,
	resource_size(r));
	if (!xprtp->fifo_base) {
	pr_err("%s ioreamp_nocache() failed\n", __func__);
	return -ENOMEM;
	}

	ret = qrtr_fifo_config_init(xprtp);
	if (ret) {
	pr_err("%s init failed ret[%d]\n", __func__, ret);
	return ret;
	}

	xprtp->ep.xmit = xprt_write;
	ret = qrtr_endpoint_register(&xprtp->ep, QRTR_EP_NID_AUTO, false);
	if (ret)
	return ret;

	if (fifo_rx_avail(&xprtp->rx_pipe))
	xprt_read_data(xprtp);

	return 0;
	}

	static const struct of_device_id qrtr_fifo_xprt_match_table[] = {
	{ .compatible = "qcom,ipcr-fifo-xprt" },
	{},
	};

	static struct platform_driver qrtr_fifo_xprt_driver = {
	.probe = qrtr_fifo_xprt_probe,
	.driver = {
	.name = "qcom_fifo_qrtr",
	.owner = THIS_MODULE,
	.of_match_table = qrtr_fifo_xprt_match_table,
	},
	};

	static int __init qrtr_fifo_xprt_init(void)
	{
	int rc;

	rc = platform_driver_register(&qrtr_fifo_xprt_driver);
	if (rc) {
	pr_err("%s: driver register failed %d\n", __func__, rc);
	return rc;
	}

	return 0;
	}

	module_init(qrtr_fifo_xprt_init);
	MODULE_DESCRIPTION("QTI IPC-router FIFO XPRT");
	MODULE_LICENSE("GPL v2");