[RFC PATCH 3/4] ultrasoc: Add ultrasoc AXI Communicator driver

[Qi Liu]

This patch adds driver for ultrasoc AXI Communicator. It includes
a platform driver to probe AXI Communicator device, a set of
operations to access the service data, and a service work entry
which will be called by the standard communicator service.

Signed-off-by: Jonathan Zhou <jonathan.zhouwen@xxxxxxxxxx>
Signed-off-by: Qi Liu <liuqi115@xxxxxxxxxx>
---
 drivers/hwtracing/ultrasoc/Kconfig            |   9 +
 drivers/hwtracing/ultrasoc/Makefile           |   3 +
 drivers/hwtracing/ultrasoc/ultrasoc-axi-com.c | 334 ++++++++++++++++++++++++++
 drivers/hwtracing/ultrasoc/ultrasoc-axi-com.h |  66 +++++
 4 files changed, 412 insertions(+)
 create mode 100644 drivers/hwtracing/ultrasoc/ultrasoc-axi-com.c
 create mode 100644 drivers/hwtracing/ultrasoc/ultrasoc-axi-com.h

diff --git a/drivers/hwtracing/ultrasoc/Kconfig b/drivers/hwtracing/ultrasoc/Kconfig
index 90a3934..77429f3 100644
--- a/drivers/hwtracing/ultrasoc/Kconfig
+++ b/drivers/hwtracing/ultrasoc/Kconfig
@@ -13,4 +13,13 @@ menuconfig ULTRASOC
 	  specification and configure the right series of components when a
 	  trace source gets enabled.
 
+if ULTRASOC
+config ULTRASOC_AXI_COM
+	tristate "Ultrasoc AXI communicator drivers"
+	help
+	  This config enables support for Ultrasoc AXI Bus Communicator
+	  drivers. The AXI Communicator has upstream and downstream channels,
+	  the upstream channel is used to transmit user configuration, and
+	  downstream channel to carry response and trace data to the users.
+
 endif
diff --git a/drivers/hwtracing/ultrasoc/Makefile b/drivers/hwtracing/ultrasoc/Makefile
index a747171..54711a7b 100644
--- a/drivers/hwtracing/ultrasoc/Makefile
+++ b/drivers/hwtracing/ultrasoc/Makefile
@@ -5,3 +5,6 @@
 
 obj-$(CONFIG_ULTRASOC) += ultrasoc-drv.o
 ultrasoc-drv-objs := ultrasoc.o
+
+obj-$(CONFIG_ULTRASOC_AXI_COM) += ultrasoc-axi-com-drv.o
+ultrasoc-axi-com-drv-objs := ultrasoc-axi-com.o
diff --git a/drivers/hwtracing/ultrasoc/ultrasoc-axi-com.c b/drivers/hwtracing/ultrasoc/ultrasoc-axi-com.c
new file mode 100644
index 0000000..af153dd
--- /dev/null
+++ b/drivers/hwtracing/ultrasoc/ultrasoc-axi-com.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2021 Hisilicon Limited Permission is hereby granted, free of
+ * charge, to any person obtaining a copy of this software and associated
+ * documentation files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject
+ * to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Code herein communicates with and accesses proprietary hardware which is
+ * licensed intellectual property (IP) belonging to Siemens Digital Industries
+ * Software Ltd.
+ *
+ * Siemens Digital Industries Software Ltd. asserts and reserves all rights to
+ * their intellectual property. This paragraph may not be removed or modified
+ * in any way without permission from Siemens Digital Industries Software Ltd.
+ */
+#include <linux/acpi.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <asm/unaligned.h>
+
+#include "ultrasoc-axi-com.h"
+
+static void axi_com_enable_hw(struct axi_com_drv_data *drvdata)
+{
+	u32 val;
+
+	val = readl(drvdata->base + AXIC_US_CTL);
+	val |= AXIC_US_CTL_EN;
+	writel(val, drvdata->base + AXIC_US_CTL);
+
+	val = readl(drvdata->base + AXIC_DS_CTL);
+	val |= AXIC_DS_CTL_EN;
+	writel(val, drvdata->base + AXIC_DS_CTL);
+}
+
+static void axi_com_disable_hw(struct axi_com_drv_data *drvdata)
+{
+	u32 val;
+
+	val = readl(drvdata->base + AXIC_US_CTL);
+	val &= ~AXIC_US_CTL_EN;
+	writel(val, drvdata->base + AXIC_US_CTL);
+
+	val = readl(drvdata->base + AXIC_DS_CTL);
+	val &= ~AXIC_DS_CTL_EN;
+	writel(val, drvdata->base + AXIC_DS_CTL);
+}
+
+static inline bool axi_com_us_buf_full(struct axi_com_drv_data *drvdata)
+{
+	return readl(drvdata->base + AXIC_US_BUF_STS) & BIT(0);
+}
+
+static inline bool axi_com_ds_buf_full(struct axi_com_drv_data *drvdata)
+{
+	return readl(drvdata->base + AXIC_DS_BUF_STS) & BIT(0);
+}
+
+static int axi_com_try_send_msg(struct axi_com_drv_data *drvdata)
+{
+	struct msg_descp *msg;
+	struct list_head *node;
+	int index = 0;
+	int unsent;
+	u32 data;
+
+	if (axi_com_us_buf_full(drvdata)) {
+		dev_err_once(drvdata->dev, "No room for upstream buffer.\n");
+		return US_SERVICE_IDLE;
+	}
+
+	spin_lock(&drvdata->us_msg_list_lock);
+	if (list_empty(&drvdata->us_msg_head)) {
+		spin_unlock(&drvdata->us_msg_list_lock);
+		return US_SERVICE_IDLE;
+	}
+
+	node = drvdata->us_msg_head.next;
+	list_del(node);
+	drvdata->us_msg_cur--;
+	msg = container_of(node, struct msg_descp, node);
+	spin_unlock(&drvdata->us_msg_list_lock);
+
+	unsent = msg->msg_len;
+	dev_dbg(drvdata->dev, "Length of send msg: %d.\n", msg->msg_len);
+	while (unsent > 0) {
+		data = get_unaligned_le32(&msg->msg_buf[index++]);
+		writel(data, drvdata->base + AXIC_US_DATA);
+		unsent -= AXIC_MSG_LEN_PER_SEND;
+	}
+	kfree(msg);
+
+	return US_SERVICE_ONWORK;
+}
+
+static int axi_com_try_recv_msg(struct axi_com_drv_data *drvdata)
+{
+	struct msg_descp tmp_msg = {0};
+	struct msg_descp *msg;
+	bool lost = false;
+	u32 index = 0;
+	u32 status, entries, data;
+
+	if (!axi_com_ds_buf_full(drvdata))
+		return US_SERVICE_IDLE;
+
+	msg = kzalloc(sizeof(*msg), GFP_KERNEL);
+	if (!msg) {
+		/*
+		 * create local variable tmp_msg to read and clear
+		 * the downstream message.
+		 */
+		msg = &tmp_msg;
+		lost = true;
+	}
+
+	do {
+		if (index == USMSG_MAX_IDX) {
+			dev_warn(drvdata->dev, "Illegal message.\n");
+			break;
+		}
+		data = readl(drvdata->base + AXIC_DS_DATA);
+		put_unaligned_le32(data, &msg->msg_buf[index++]);
+		status = readl(drvdata->base + AXIC_DS_RD_STS);
+		entries = status & GENMASK(7, 4);
+		msg->msg_len += AXIC_MSG_LEN_PER_REC;
+	} while (entries != 0);
+
+	if (!lost) {
+		spin_lock(&drvdata->ds_msg_list_lock);
+		drvdata->ds_msg_cur++;
+		drvdata->ds_msg_counter++;
+		list_add_tail(&msg->node, &drvdata->ds_msg_head);
+		spin_unlock(&drvdata->ds_msg_list_lock);
+	}
+
+	return US_SERVICE_ONWORK;
+}
+
+static int axi_com_work(struct ultrasoc_com *uscom)
+{
+	struct axi_com_drv_data *drvdata = ultrasoc_com_get_drvdata(uscom);
+	int us_ds_flag;
+
+	us_ds_flag = axi_com_try_recv_msg(drvdata);
+	us_ds_flag |= axi_com_try_send_msg(drvdata);
+
+	return us_ds_flag;
+}
+
+static ssize_t axi_com_show_status(struct ultrasoc_com *uscom, char *buf,
+				   ssize_t wr_size)
+{
+	struct axi_com_drv_data *drvdata = ultrasoc_com_get_drvdata(uscom);
+
+	wr_size += sysfs_emit_at(buf, wr_size, "%-20s: %d\n",
+				 "ds msg list num", drvdata->ds_msg_cur);
+	wr_size += sysfs_emit_at(buf, wr_size, "%-20s: %d\n",
+				 "us msg list num", drvdata->us_msg_cur);
+
+	return wr_size;
+}
+
+static void axi_com_put_raw_msg(struct ultrasoc_com *uscom, int msg_size,
+			unsigned long long msg_data)
+{
+	struct axi_com_drv_data *drvdata = ultrasoc_com_get_drvdata(uscom);
+	struct msg_descp *p_msg;
+
+	p_msg = kmalloc(sizeof(*p_msg), GFP_KERNEL);
+	if (!p_msg)
+		return;
+
+	p_msg->msg_len = msg_size;
+	put_unaligned_le64(msg_data, &p_msg->msg_buf[0]);
+	spin_lock(&drvdata->us_msg_list_lock);
+	list_add_tail(&p_msg->node, &drvdata->us_msg_head);
+	drvdata->us_msg_cur++;
+	spin_unlock(&drvdata->us_msg_list_lock);
+
+	if (uscom->service_status != ULTRASOC_COM_SERVICE_STOPPED)
+		wake_up_process(uscom->service);
+	else
+		dev_warn(uscom->dev, "Com service is not running.\n");
+}
+
+static struct uscom_ops axi_com_ops = {
+	.com_status = axi_com_show_status,
+	.put_raw_msg = axi_com_put_raw_msg,
+};
+
+/*
+ * Config hardwares on the tracing path, using DSM calls to avoid exposing
+ * hardware message format.
+ */
+static int axi_com_config_inport(struct axi_com_drv_data *drvdata, bool enable)
+{
+	struct device *dev = drvdata->dev;
+	u32 flag = enable ? 1 : 0;
+	union acpi_object *obj;
+	guid_t guid;
+
+	if (guid_parse("82ae1283-7f6a-4cbe-aa06-53e8fb24db18", &guid)) {
+		dev_err(dev, "Get GUID failed.\n");
+		return -EINVAL;
+	}
+
+	obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, 0, flag, NULL);
+	if (!obj)
+		dev_err(dev, "ACPI handle failed!\n");
+
+	ACPI_FREE(obj);
+
+	return 0;
+}
+
+static int axi_com_config_com_descp(struct platform_device *pdev,
+				    struct axi_com_drv_data *drvdata)
+{
+	struct device *parent = pdev->dev.parent;
+	struct ultrasoc_com_descp com_descp = {0};
+	struct device *dev = &pdev->dev;
+	struct ultrasoc_com *com;
+
+	com_descp.name = pdev->name;
+	com_descp.com_type = ULTRASOC_COM_TYPE_BOTH;
+	com_descp.com_dev = dev;
+	com_descp.uscom_ops = &axi_com_ops;
+	com_descp.com_work = axi_com_work;
+
+	if (device_property_read_u64(dev, "ultrasoc,default_route",
+				     &com_descp.default_route_msg)) {
+		dev_err(dev, "Failed to read default_route!\n");
+		return -EINVAL;
+	}
+
+	com = ultrasoc_register_com(parent, &com_descp);
+	if (IS_ERR(com)) {
+		dev_err(dev, "Failed to register to ultrasoc.\n");
+		return PTR_ERR(com);
+	}
+
+	/*
+	 * record the returned com point in drvdata,
+	 * it will be used to unregister the com
+	 * from ultrasoc.
+	 */
+	drvdata->com = com;
+	return 0;
+}
+
+static int axi_com_probe(struct platform_device *pdev)
+{
+	struct axi_com_drv_data *drvdata;
+	int ret;
+
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(drvdata->base)) {
+		dev_err(&pdev->dev, "Failed to ioremap resource.\n");
+		return PTR_ERR(drvdata->base);
+	}
+
+	drvdata->dev = &pdev->dev;
+	spin_lock_init(&drvdata->ds_msg_list_lock);
+	spin_lock_init(&drvdata->us_msg_list_lock);
+	INIT_LIST_HEAD(&drvdata->us_msg_head);
+	INIT_LIST_HEAD(&drvdata->ds_msg_head);
+
+	axi_com_enable_hw(drvdata);
+	ret = axi_com_config_inport(drvdata, true);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, drvdata);
+	return axi_com_config_com_descp(pdev, drvdata);
+}
+
+static int axi_com_remove(struct platform_device *pdev)
+{
+	struct axi_com_drv_data *drvdata = platform_get_drvdata(pdev);
+	int ret;
+
+	if (ultrasoc_unregister_com(drvdata->com) == -EBUSY)
+		return -EBUSY;
+
+	ret = axi_com_config_inport(drvdata, false);
+	if (ret)
+		return ret;
+
+	axi_com_disable_hw(drvdata);
+	usmsg_list_realse_all(&drvdata->ds_msg_head);
+	usmsg_list_realse_all(&drvdata->us_msg_head);
+
+	return 0;
+}
+
+static const struct acpi_device_id ultrasoc_axi_com_acpi_match[] = {
+	{"HISI03B1", },
+	{},
+};
+
+static struct platform_driver axi_com_driver = {
+	.driver = {
+		.name = "ultrasoc,axi-com",
+		.acpi_match_table = ultrasoc_axi_com_acpi_match,
+	},
+	.probe = axi_com_probe,
+	.remove = axi_com_remove,
+};
+module_platform_driver(axi_com_driver);
+
+MODULE_DESCRIPTION("Ultrasoc AXI COM driver");
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@xxxxxxxxxx>");
+MODULE_AUTHOR("Qi Liu <liuqi115@xxxxxxxxxx>");
diff --git a/drivers/hwtracing/ultrasoc/ultrasoc-axi-com.h b/drivers/hwtracing/ultrasoc/ultrasoc-axi-com.h
new file mode 100644
index 0000000..64bcf83
--- /dev/null
+++ b/drivers/hwtracing/ultrasoc/ultrasoc-axi-com.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (C) 2021 Hisilicon Limited Permission is hereby granted, free of
+ * charge, to any person obtaining a copy of this software and associated
+ * documentation files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject
+ * to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Code herein communicates with and accesses proprietary hardware which is
+ * licensed intellectual property (IP) belonging to Siemens Digital Industries
+ * Software Ltd.
+ *
+ * Siemens Digital Industries Software Ltd. asserts and reserves all rights to
+ * their intellectual property. This paragraph may not be removed or modified
+ * in any way without permission from Siemens Digital Industries Software Ltd.
+ */
+#ifndef ULTRASOC_AXI_COM_H
+#define ULTRASOC_AXI_COM_H
+
+#include "ultrasoc.h"
+
+#define AXIC_US_CTL 0X0 /* Upstream general control */
+#define AXIC_US_DATA 0XC /* Upstream message data */
+#define AXIC_US_BUF_STS 0X10 /* Upstream buffer status */
+
+#define AXIC_DS_CTL 0X80 /* Downstream general contral */
+#define AXIC_DS_DATA 0X8C /* Downstream message data */
+#define AXIC_DS_BUF_STS 0X90 /* Downstream buffer status */
+#define AXIC_DS_RD_STS 0X94 /* Downstream read status */
+
+#define AXIC_MSG_LEN_PER_SEND		4
+#define AXIC_MSG_LEN_PER_REC		4
+#define AXIC_US_CTL_EN 0x1
+#define AXIC_DS_CTL_EN 0x1
+
+struct axi_com_drv_data {
+	void __iomem *base;
+
+	struct device *dev;
+	struct ultrasoc_com *com;
+
+	u32 ds_msg_counter;
+
+	u32 us_msg_cur;
+	spinlock_t us_msg_list_lock;
+	struct list_head us_msg_head;
+
+	u32 ds_msg_cur;
+	spinlock_t ds_msg_list_lock;
+	struct list_head ds_msg_head;
+};
+
+#endif
-- 
2.7.4