drivers/rpmsg/qcom_glink_rpm.c - arm/linux - Git at Google

 /*
  * Copyright (c) 2016-2017, Linaro Ltd
  *
  * 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/idr.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/list.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/rpmsg.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/mailbox_client.h>

 #include "rpmsg_internal.h"
 #include "qcom_glink_native.h"

 #define RPM_TOC_SIZE		256
 #define RPM_TOC_MAGIC		0x67727430 /* grt0 */
 #define RPM_TOC_MAX_ENTRIES	((RPM_TOC_SIZE - sizeof(struct rpm_toc)) / \
 				 sizeof(struct rpm_toc_entry))

 #define RPM_TX_FIFO_ID		0x61703272 /* ap2r */
 #define RPM_RX_FIFO_ID		0x72326170 /* r2ap */

 #define to_rpm_pipe(p) container_of(p, struct glink_rpm_pipe, native)

 struct rpm_toc_entry {
 	__le32 id;
 	__le32 offset;
 	__le32 size;
 } __packed;

 struct rpm_toc {
 	__le32 magic;
 	__le32 count;

 	struct rpm_toc_entry entries[];
 } __packed;

 struct glink_rpm_pipe {
 	struct qcom_glink_pipe native;

 	void __iomem *tail;
 	void __iomem *head;

 	void __iomem *fifo;
 };

 static size_t glink_rpm_rx_avail(struct qcom_glink_pipe *glink_pipe)
 {
 	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int head;
 	unsigned int tail;

 	head = readl(pipe->head);
 	tail = readl(pipe->tail);

 	if (head < tail)
 		return pipe->native.length - tail + head;
 	else
 		return head - tail;
 }

 static void glink_rpm_rx_peak(struct qcom_glink_pipe *glink_pipe,
 			      void *data, unsigned int offset, size_t count)
 {
 	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int tail;
 	size_t len;

 	tail = readl(pipe->tail);
 	tail += offset;
 	if (tail >= pipe->native.length)
 		tail -= pipe->native.length;

 	len = min_t(size_t, count, pipe->native.length - tail);
 	if (len) {
 		__ioread32_copy(data, pipe->fifo + tail,
 				len / sizeof(u32));
 	}

 	if (len != count) {
 		__ioread32_copy(data + len, pipe->fifo,
 				(count - len) / sizeof(u32));
 	}
 }

 static void glink_rpm_rx_advance(struct qcom_glink_pipe *glink_pipe,
 				 size_t count)
 {
 	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int tail;

 	tail = readl(pipe->tail);

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

 	writel(tail, pipe->tail);
 }

 static size_t glink_rpm_tx_avail(struct qcom_glink_pipe *glink_pipe)
 {
 	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int head;
 	unsigned int tail;

 	head = readl(pipe->head);
 	tail = readl(pipe->tail);

 	if (tail <= head)
 		return pipe->native.length - head + tail;
 	else
 		return tail - head;
 }

 static unsigned int glink_rpm_tx_write_one(struct glink_rpm_pipe *pipe,
 					   unsigned int head,
 					   const void *data, size_t count)
 {
 	size_t len;

 	len = min_t(size_t, count, pipe->native.length - head);
 	if (len) {
 		__iowrite32_copy(pipe->fifo + head, data,
 				 len / sizeof(u32));
 	}

 	if (len != count) {
 		__iowrite32_copy(pipe->fifo, data + len,
 				 (count - len) / sizeof(u32));
 	}

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

 	return head;
 }

 static void glink_rpm_tx_write(struct qcom_glink_pipe *glink_pipe,
 			       const void *hdr, size_t hlen,
 			       const void *data, size_t dlen)
 {
 	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	size_t tlen = hlen + dlen;
 	size_t aligned_dlen;
 	unsigned int head;
 	char padding[8] = {0};
 	size_t pad;

 	/* Header length comes from glink native and is always 4 byte aligned */
 	if (WARN(hlen % 4, "Glink Header length must be 4 bytes aligned\n"))
 		return;

 	/*
 	 * Move the unaligned tail of the message to the padding chunk, to
 	 * ensure word aligned accesses
 	 */
 	aligned_dlen = ALIGN_DOWN(dlen, 4);
 	if (aligned_dlen != dlen)
 		memcpy(padding, data + aligned_dlen, dlen - aligned_dlen);

 	head = readl(pipe->head);
 	head = glink_rpm_tx_write_one(pipe, head, hdr, hlen);
 	head = glink_rpm_tx_write_one(pipe, head, data, aligned_dlen);

 	pad = ALIGN(tlen, 8) - ALIGN_DOWN(tlen, 4);
 	if (pad)
 		head = glink_rpm_tx_write_one(pipe, head, padding, pad);
 	writel(head, pipe->head);
 }

 static int glink_rpm_parse_toc(struct device *dev,
 			       void __iomem *msg_ram,
 			       size_t msg_ram_size,
 			       struct glink_rpm_pipe *rx,
 			       struct glink_rpm_pipe *tx)
 {
 	struct rpm_toc *toc;
 	int num_entries;
 	unsigned int id;
 	size_t offset;
 	size_t size;
 	void *buf;
 	int i;

 	buf = kzalloc(RPM_TOC_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;

 	__ioread32_copy(buf, msg_ram + msg_ram_size - RPM_TOC_SIZE,
 			RPM_TOC_SIZE / sizeof(u32));

 	toc = buf;

 	if (le32_to_cpu(toc->magic) != RPM_TOC_MAGIC) {
 		dev_err(dev, "RPM TOC has invalid magic\n");
 		goto err_inval;
 	}

 	num_entries = le32_to_cpu(toc->count);
 	if (num_entries > RPM_TOC_MAX_ENTRIES) {
 		dev_err(dev, "Invalid number of toc entries\n");
 		goto err_inval;
 	}

 	for (i = 0; i < num_entries; i++) {
 		id = le32_to_cpu(toc->entries[i].id);
 		offset = le32_to_cpu(toc->entries[i].offset);
 		size = le32_to_cpu(toc->entries[i].size);

 		if (offset > msg_ram_size || offset + size > msg_ram_size) {
 			dev_err(dev, "TOC entry with invalid size\n");
 			continue;
 		}

 		switch (id) {
 		case RPM_RX_FIFO_ID:
 			rx->native.length = size;

 			rx->tail = msg_ram + offset;
 			rx->head = msg_ram + offset + sizeof(u32);
 			rx->fifo = msg_ram + offset + 2 * sizeof(u32);
 			break;
 		case RPM_TX_FIFO_ID:
 			tx->native.length = size;

 			tx->tail = msg_ram + offset;
 			tx->head = msg_ram + offset + sizeof(u32);
 			tx->fifo = msg_ram + offset + 2 * sizeof(u32);
 			break;
 		}
 	}

 	if (!rx->fifo || !tx->fifo) {
 		dev_err(dev, "Unable to find rx and tx descriptors\n");
 		goto err_inval;
 	}

 	kfree(buf);
 	return 0;

 err_inval:
 	kfree(buf);
 	return -EINVAL;
 }

 static int glink_rpm_probe(struct platform_device *pdev)
 {
 	struct qcom_glink *glink;
 	struct glink_rpm_pipe *rx_pipe;
 	struct glink_rpm_pipe *tx_pipe;
 	struct device_node *np;
 	void __iomem *msg_ram;
 	size_t msg_ram_size;
 	struct device *dev = &pdev->dev;
 	struct resource r;
 	int ret;

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

 	np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", 0);
 	ret = of_address_to_resource(np, 0, &r);
 	of_node_put(np);
 	if (ret)
 		return ret;

 	msg_ram = devm_ioremap(dev, r.start, resource_size(&r));
 	msg_ram_size = resource_size(&r);
 	if (!msg_ram)
 		return -ENOMEM;

 	ret = glink_rpm_parse_toc(dev, msg_ram, msg_ram_size,
 				  rx_pipe, tx_pipe);
 	if (ret)
 		return ret;

 	/* Pipe specific accessors */
 	rx_pipe->native.avail = glink_rpm_rx_avail;
 	rx_pipe->native.peak = glink_rpm_rx_peak;
 	rx_pipe->native.advance = glink_rpm_rx_advance;
 	tx_pipe->native.avail = glink_rpm_tx_avail;
 	tx_pipe->native.write = glink_rpm_tx_write;

 	writel(0, tx_pipe->head);
 	writel(0, rx_pipe->tail);

 	glink = qcom_glink_native_probe(&pdev->dev,
 					0,
 					&rx_pipe->native,
 					&tx_pipe->native,
 					true);
 	if (IS_ERR(glink))
 		return PTR_ERR(glink);

 	platform_set_drvdata(pdev, glink);

 	return 0;
 }

 static int glink_rpm_remove(struct platform_device *pdev)
 {
 	struct qcom_glink *glink = platform_get_drvdata(pdev);

 	qcom_glink_native_remove(glink);

 	return 0;
 }

 static const struct of_device_id glink_rpm_of_match[] = {
 	{ .compatible = "qcom,glink-rpm" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, glink_rpm_of_match);

 static struct platform_driver glink_rpm_driver = {
 	.probe = glink_rpm_probe,
 	.remove = glink_rpm_remove,
 	.driver = {
 		.name = "qcom_glink_rpm",
 		.of_match_table = glink_rpm_of_match,
 	},
 };

 static int __init glink_rpm_init(void)
 {
 	return platform_driver_register(&glink_rpm_driver);
 }
 subsys_initcall(glink_rpm_init);

 static void __exit glink_rpm_exit(void)
 {
 	platform_driver_unregister(&glink_rpm_driver);
 }
 module_exit(glink_rpm_exit);

 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
 MODULE_DESCRIPTION("Qualcomm GLINK RPM driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (c) 2016-2017, Linaro Ltd
	*
	* 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/idr.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/list.h>
	#include <linux/mfd/syscon.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/rpmsg.h>
	#include <linux/slab.h>
	#include <linux/workqueue.h>
	#include <linux/mailbox_client.h>

	#include "rpmsg_internal.h"
	#include "qcom_glink_native.h"

	#define RPM_TOC_SIZE 256
	#define RPM_TOC_MAGIC 0x67727430 /* grt0 */
	#define RPM_TOC_MAX_ENTRIES ((RPM_TOC_SIZE - sizeof(struct rpm_toc)) / \
	sizeof(struct rpm_toc_entry))

	#define RPM_TX_FIFO_ID 0x61703272 /* ap2r */
	#define RPM_RX_FIFO_ID 0x72326170 /* r2ap */

	#define to_rpm_pipe(p) container_of(p, struct glink_rpm_pipe, native)

	struct rpm_toc_entry {
	__le32 id;
	__le32 offset;
	__le32 size;
	} __packed;

	struct rpm_toc {
	__le32 magic;
	__le32 count;

	struct rpm_toc_entry entries[];
	} __packed;

	struct glink_rpm_pipe {
	struct qcom_glink_pipe native;

	void __iomem *tail;
	void __iomem *head;

	void __iomem *fifo;
	};

	static size_t glink_rpm_rx_avail(struct qcom_glink_pipe *glink_pipe)
	{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	unsigned int head;
	unsigned int tail;

	head = readl(pipe->head);
	tail = readl(pipe->tail);

	if (head < tail)
	return pipe->native.length - tail + head;
	else
	return head - tail;
	}

	static void glink_rpm_rx_peak(struct qcom_glink_pipe *glink_pipe,
	void *data, unsigned int offset, size_t count)
	{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	unsigned int tail;
	size_t len;

	tail = readl(pipe->tail);
	tail += offset;
	if (tail >= pipe->native.length)
	tail -= pipe->native.length;

	len = min_t(size_t, count, pipe->native.length - tail);
	if (len) {
	__ioread32_copy(data, pipe->fifo + tail,
	len / sizeof(u32));
	}

	if (len != count) {
	__ioread32_copy(data + len, pipe->fifo,
	(count - len) / sizeof(u32));
	}
	}

	static void glink_rpm_rx_advance(struct qcom_glink_pipe *glink_pipe,
	size_t count)
	{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	unsigned int tail;

	tail = readl(pipe->tail);

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

	writel(tail, pipe->tail);
	}

	static size_t glink_rpm_tx_avail(struct qcom_glink_pipe *glink_pipe)
	{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	unsigned int head;
	unsigned int tail;

	head = readl(pipe->head);
	tail = readl(pipe->tail);

	if (tail <= head)
	return pipe->native.length - head + tail;
	else
	return tail - head;
	}

	static unsigned int glink_rpm_tx_write_one(struct glink_rpm_pipe *pipe,
	unsigned int head,
	const void *data, size_t count)
	{
	size_t len;

	len = min_t(size_t, count, pipe->native.length - head);
	if (len) {
	__iowrite32_copy(pipe->fifo + head, data,
	len / sizeof(u32));
	}

	if (len != count) {
	__iowrite32_copy(pipe->fifo, data + len,
	(count - len) / sizeof(u32));
	}

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

	return head;
	}

	static void glink_rpm_tx_write(struct qcom_glink_pipe *glink_pipe,
	const void *hdr, size_t hlen,
	const void *data, size_t dlen)
	{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	size_t tlen = hlen + dlen;
	size_t aligned_dlen;
	unsigned int head;
	char padding[8] = {0};
	size_t pad;

	/* Header length comes from glink native and is always 4 byte aligned */
	if (WARN(hlen % 4, "Glink Header length must be 4 bytes aligned\n"))
	return;

	/*
	* Move the unaligned tail of the message to the padding chunk, to
	* ensure word aligned accesses
	*/
	aligned_dlen = ALIGN_DOWN(dlen, 4);
	if (aligned_dlen != dlen)
	memcpy(padding, data + aligned_dlen, dlen - aligned_dlen);

	head = readl(pipe->head);
	head = glink_rpm_tx_write_one(pipe, head, hdr, hlen);
	head = glink_rpm_tx_write_one(pipe, head, data, aligned_dlen);

	pad = ALIGN(tlen, 8) - ALIGN_DOWN(tlen, 4);
	if (pad)
	head = glink_rpm_tx_write_one(pipe, head, padding, pad);
	writel(head, pipe->head);
	}

	static int glink_rpm_parse_toc(struct device *dev,
	void __iomem *msg_ram,
	size_t msg_ram_size,
	struct glink_rpm_pipe *rx,
	struct glink_rpm_pipe *tx)
	{
	struct rpm_toc *toc;
	int num_entries;
	unsigned int id;
	size_t offset;
	size_t size;
	void *buf;
	int i;

	buf = kzalloc(RPM_TOC_SIZE, GFP_KERNEL);
	if (!buf)
	return -ENOMEM;

	__ioread32_copy(buf, msg_ram + msg_ram_size - RPM_TOC_SIZE,
	RPM_TOC_SIZE / sizeof(u32));

	toc = buf;

	if (le32_to_cpu(toc->magic) != RPM_TOC_MAGIC) {
	dev_err(dev, "RPM TOC has invalid magic\n");
	goto err_inval;
	}

	num_entries = le32_to_cpu(toc->count);
	if (num_entries > RPM_TOC_MAX_ENTRIES) {
	dev_err(dev, "Invalid number of toc entries\n");
	goto err_inval;
	}

	for (i = 0; i < num_entries; i++) {
	id = le32_to_cpu(toc->entries[i].id);
	offset = le32_to_cpu(toc->entries[i].offset);
	size = le32_to_cpu(toc->entries[i].size);

	if (offset > msg_ram_size \|\| offset + size > msg_ram_size) {
	dev_err(dev, "TOC entry with invalid size\n");
	continue;
	}

	switch (id) {
	case RPM_RX_FIFO_ID:
	rx->native.length = size;

	rx->tail = msg_ram + offset;
	rx->head = msg_ram + offset + sizeof(u32);
	rx->fifo = msg_ram + offset + 2 * sizeof(u32);
	break;
	case RPM_TX_FIFO_ID:
	tx->native.length = size;

	tx->tail = msg_ram + offset;
	tx->head = msg_ram + offset + sizeof(u32);
	tx->fifo = msg_ram + offset + 2 * sizeof(u32);
	break;
	}
	}

	if (!rx->fifo \|\| !tx->fifo) {
	dev_err(dev, "Unable to find rx and tx descriptors\n");
	goto err_inval;
	}

	kfree(buf);
	return 0;

	err_inval:
	kfree(buf);
	return -EINVAL;
	}

	static int glink_rpm_probe(struct platform_device *pdev)
	{
	struct qcom_glink *glink;
	struct glink_rpm_pipe *rx_pipe;
	struct glink_rpm_pipe *tx_pipe;
	struct device_node *np;
	void __iomem *msg_ram;
	size_t msg_ram_size;
	struct device *dev = &pdev->dev;
	struct resource r;
	int ret;

	rx_pipe = devm_kzalloc(&pdev->dev, sizeof(*rx_pipe), GFP_KERNEL);
	tx_pipe = devm_kzalloc(&pdev->dev, sizeof(*tx_pipe), GFP_KERNEL);
	if (!rx_pipe \|\| !tx_pipe)
	return -ENOMEM;

	np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", 0);
	ret = of_address_to_resource(np, 0, &r);
	of_node_put(np);
	if (ret)
	return ret;

	msg_ram = devm_ioremap(dev, r.start, resource_size(&r));
	msg_ram_size = resource_size(&r);
	if (!msg_ram)
	return -ENOMEM;

	ret = glink_rpm_parse_toc(dev, msg_ram, msg_ram_size,
	rx_pipe, tx_pipe);
	if (ret)
	return ret;

	/* Pipe specific accessors */
	rx_pipe->native.avail = glink_rpm_rx_avail;
	rx_pipe->native.peak = glink_rpm_rx_peak;
	rx_pipe->native.advance = glink_rpm_rx_advance;
	tx_pipe->native.avail = glink_rpm_tx_avail;
	tx_pipe->native.write = glink_rpm_tx_write;

	writel(0, tx_pipe->head);
	writel(0, rx_pipe->tail);

	glink = qcom_glink_native_probe(&pdev->dev,
	0,
	&rx_pipe->native,
	&tx_pipe->native,
	true);
	if (IS_ERR(glink))
	return PTR_ERR(glink);

	platform_set_drvdata(pdev, glink);

	return 0;
	}

	static int glink_rpm_remove(struct platform_device *pdev)
	{
	struct qcom_glink *glink = platform_get_drvdata(pdev);

	qcom_glink_native_remove(glink);

	return 0;
	}

	static const struct of_device_id glink_rpm_of_match[] = {
	{ .compatible = "qcom,glink-rpm" },
	{}
	};
	MODULE_DEVICE_TABLE(of, glink_rpm_of_match);

	static struct platform_driver glink_rpm_driver = {
	.probe = glink_rpm_probe,
	.remove = glink_rpm_remove,
	.driver = {
	.name = "qcom_glink_rpm",
	.of_match_table = glink_rpm_of_match,
	},
	};

	static int __init glink_rpm_init(void)
	{
	return platform_driver_register(&glink_rpm_driver);
	}
	subsys_initcall(glink_rpm_init);

	static void __exit glink_rpm_exit(void)
	{
	platform_driver_unregister(&glink_rpm_driver);
	}
	module_exit(glink_rpm_exit);

	MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
	MODULE_DESCRIPTION("Qualcomm GLINK RPM driver");
	MODULE_LICENSE("GPL v2");