1 files changed, 405 insertions, 0 deletions
diff --git a/drivers/rpmsg/qcom_glink_rpm.c b/drivers/rpmsg/qcom_glink_rpm.c
new file mode 100644
index 0000000000..357272d706
--- /dev/null
+++ b/drivers/rpmsg/qcom_glink_rpm.c
@@ -0,0 +1,405 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016-2017, Linaro Ltd
+ */
+
+#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/of_irq.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;
+};
+
+struct glink_rpm {
+	struct qcom_glink *glink;
+
+	int irq;
+
+	struct mbox_client mbox_client;
+	struct mbox_chan *mbox_chan;
+
+	struct glink_rpm_pipe rx_pipe;
+	struct glink_rpm_pipe tx_pipe;
+};
+
+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_peek(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 void glink_rpm_tx_kick(struct qcom_glink_pipe *glink_pipe)
+{
+	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
+	struct glink_rpm *rpm = container_of(pipe, struct glink_rpm, tx_pipe);
+
+	mbox_send_message(rpm->mbox_chan, NULL);
+	mbox_client_txdone(rpm->mbox_chan, 0);
+}
+
+static irqreturn_t qcom_glink_rpm_intr(int irq, void *data)
+{
+	struct glink_rpm *rpm = data;
+
+	qcom_glink_native_rx(rpm->glink);
+
+	return IRQ_HANDLED;
+}
+
+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 *rpm;
+	struct device_node *np;
+	void __iomem *msg_ram;
+	size_t msg_ram_size;
+	struct device *dev = &pdev->dev;
+	struct resource r;
+	int ret;
+
+	rpm = devm_kzalloc(&pdev->dev, sizeof(*rpm), GFP_KERNEL);
+	if (!rpm)
+		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,
+				  &rpm->rx_pipe, &rpm->tx_pipe);
+	if (ret)
+		return ret;
+
+	rpm->irq = of_irq_get(dev->of_node, 0);
+	ret = devm_request_irq(dev, rpm->irq, qcom_glink_rpm_intr,
+			       IRQF_NO_SUSPEND | IRQF_NO_AUTOEN,
+			       "glink-rpm", rpm);
+	if (ret) {
+		dev_err(dev, "failed to request IRQ\n");
+		return ret;
+	}
+
+	rpm->mbox_client.dev = dev;
+	rpm->mbox_client.knows_txdone = true;
+	rpm->mbox_chan = mbox_request_channel(&rpm->mbox_client, 0);
+	if (IS_ERR(rpm->mbox_chan))
+		return dev_err_probe(dev, PTR_ERR(rpm->mbox_chan), "failed to acquire IPC channel\n");
+
+	/* Pipe specific accessors */
+	rpm->rx_pipe.native.avail = glink_rpm_rx_avail;
+	rpm->rx_pipe.native.peek = glink_rpm_rx_peek;
+	rpm->rx_pipe.native.advance = glink_rpm_rx_advance;
+	rpm->tx_pipe.native.avail = glink_rpm_tx_avail;
+	rpm->tx_pipe.native.write = glink_rpm_tx_write;
+	rpm->tx_pipe.native.kick = glink_rpm_tx_kick;
+
+	writel(0, rpm->tx_pipe.head);
+	writel(0, rpm->rx_pipe.tail);
+
+	glink = qcom_glink_native_probe(dev,
+					0,
+					&rpm->rx_pipe.native,
+					&rpm->tx_pipe.native,
+					true);
+	if (IS_ERR(glink)) {
+		mbox_free_channel(rpm->mbox_chan);
+		return PTR_ERR(glink);
+	}
+
+	rpm->glink = glink;
+
+	platform_set_drvdata(pdev, rpm);
+
+	enable_irq(rpm->irq);
+
+	return 0;
+}
+
+static void glink_rpm_remove(struct platform_device *pdev)
+{
+	struct glink_rpm *rpm = platform_get_drvdata(pdev);
+	struct qcom_glink *glink = rpm->glink;
+
+	disable_irq(rpm->irq);
+
+	qcom_glink_native_remove(glink);
+
+	mbox_free_channel(rpm->mbox_chan);
+}
+
+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_new = 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");