[PATCH v4 5/5] samples: Introduce Qualcomm QMI sample client

[Bjorn Andersson]

Introduce a sample driver that register for server notifications and
spawn clients for each available test service (service 15). The spawned
clients implements the interface for encoding "ping" and "data" requests
and decode the responses from the remote.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

Changes since v3:
- Kerneldoc updates

Changes since v2:
- Fix some kerneldoc typos
- Checkpatch fixes

Changes since v1:
- Adapted to updated QMI helper interface
- Moved user space interface to debugfs

 samples/Kconfig                 |   9 +
 samples/Makefile                |   2 +-
 samples/qmi/Makefile            |   1 +
 samples/qmi/qmi_sample_client.c | 631 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 642 insertions(+), 1 deletion(-)
 create mode 100644 samples/qmi/Makefile
 create mode 100644 samples/qmi/qmi_sample_client.c

diff --git a/samples/Kconfig b/samples/Kconfig
index c332a3b9de05..4cb8af2f810f 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -62,6 +62,15 @@ config SAMPLE_KDB
 	  Build an example of how to dynamically add the hello
 	  command to the kdb shell.
 
+config SAMPLE_QMI_CLIENT
+	tristate "Build qmi client sample -- loadable modules only"
+	depends on m
+	depends on ARCH_QCOM
+	select QCOM_QMI_HELPERS
+	help
+	  Build an QMI client sample driver, which demonstrates how to
+	  communicate with a remote QRTR service, using QMI encoded messages.
+
 config SAMPLE_RPMSG_CLIENT
 	tristate "Build rpmsg client sample -- loadable modules only"
 	depends on RPMSG && m
diff --git a/samples/Makefile b/samples/Makefile
index db54e766ddb1..a30833a2a19e 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -3,4 +3,4 @@
 obj-$(CONFIG_SAMPLES)	+= kobject/ kprobes/ trace_events/ livepatch/ \
 			   hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \
 			   configfs/ connector/ v4l/ trace_printk/ blackfin/ \
-			   vfio-mdev/ statx/
+			   vfio-mdev/ statx/ qmi/
diff --git a/samples/qmi/Makefile b/samples/qmi/Makefile
new file mode 100644
index 000000000000..2b111d2769df
--- /dev/null
+++ b/samples/qmi/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_SAMPLE_QMI_CLIENT) += qmi_sample_client.o
diff --git a/samples/qmi/qmi_sample_client.c b/samples/qmi/qmi_sample_client.c
new file mode 100644
index 000000000000..3ff722ced52c
--- /dev/null
+++ b/samples/qmi/qmi_sample_client.c
@@ -0,0 +1,631 @@
+/*
+ * Sample in-kernel QMI client driver
+ *
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2017 Linaro Ltd.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/qrtr.h>
+#include <linux/net.h>
+#include <linux/completion.h>
+#include <linux/idr.h>
+#include <linux/string.h>
+#include <net/sock.h>
+#include <linux/soc/qcom/qmi.h>
+
+#define PING_REQ1_TLV_TYPE		0x1
+#define PING_RESP1_TLV_TYPE		0x2
+#define PING_OPT1_TLV_TYPE		0x10
+#define PING_OPT2_TLV_TYPE		0x11
+
+#define DATA_REQ1_TLV_TYPE		0x1
+#define DATA_RESP1_TLV_TYPE		0x2
+#define DATA_OPT1_TLV_TYPE		0x10
+#define DATA_OPT2_TLV_TYPE		0x11
+
+#define TEST_MED_DATA_SIZE_V01		8192
+#define TEST_MAX_NAME_SIZE_V01		255
+
+#define TEST_PING_REQ_MSG_ID_V01	0x20
+#define TEST_DATA_REQ_MSG_ID_V01	0x21
+
+#define TEST_PING_REQ_MAX_MSG_LEN_V01	266
+#define TEST_DATA_REQ_MAX_MSG_LEN_V01	8456
+
+struct test_name_type_v01 {
+	u32 name_len;
+	char name[TEST_MAX_NAME_SIZE_V01];
+};
+
+static struct qmi_elem_info test_name_type_v01_ei[] = {
+	{
+		.data_type	= QMI_DATA_LEN,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+		.offset		= offsetof(struct test_name_type_v01,
+					   name_len),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= TEST_MAX_NAME_SIZE_V01,
+		.elem_size	= sizeof(char),
+		.array_type	= VAR_LEN_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+		.offset		= offsetof(struct test_name_type_v01,
+					   name),
+	},
+	{}
+};
+
+struct test_ping_req_msg_v01 {
+	char ping[4];
+
+	u8 client_name_valid;
+	struct test_name_type_v01 client_name;
+};
+
+static struct qmi_elem_info test_ping_req_msg_v01_ei[] = {
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 4,
+		.elem_size	= sizeof(char),
+		.array_type	= STATIC_ARRAY,
+		.tlv_type	= PING_REQ1_TLV_TYPE,
+		.offset		= offsetof(struct test_ping_req_msg_v01,
+					   ping),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= PING_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_ping_req_msg_v01,
+					   client_name_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct test_name_type_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= PING_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_ping_req_msg_v01,
+					   client_name),
+		.ei_array	= test_name_type_v01_ei,
+	},
+	{}
+};
+
+struct test_ping_resp_msg_v01 {
+	struct qmi_response_type_v01 resp;
+
+	u8 pong_valid;
+	char pong[4];
+
+	u8 service_name_valid;
+	struct test_name_type_v01 service_name;
+};
+
+static struct qmi_elem_info test_ping_resp_msg_v01_ei[] = {
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct qmi_response_type_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= PING_RESP1_TLV_TYPE,
+		.offset		= offsetof(struct test_ping_resp_msg_v01,
+					   resp),
+		.ei_array	= qmi_response_type_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= PING_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_ping_resp_msg_v01,
+					   pong_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 4,
+		.elem_size	= sizeof(char),
+		.array_type	= STATIC_ARRAY,
+		.tlv_type	= PING_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_ping_resp_msg_v01,
+					   pong),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= PING_OPT2_TLV_TYPE,
+		.offset		= offsetof(struct test_ping_resp_msg_v01,
+					   service_name_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct test_name_type_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= PING_OPT2_TLV_TYPE,
+		.offset		= offsetof(struct test_ping_resp_msg_v01,
+					   service_name),
+		.ei_array	= test_name_type_v01_ei,
+	},
+	{}
+};
+
+struct test_data_req_msg_v01 {
+	u32 data_len;
+	u8 data[TEST_MED_DATA_SIZE_V01];
+
+	u8 client_name_valid;
+	struct test_name_type_v01 client_name;
+};
+
+static struct qmi_elem_info test_data_req_msg_v01_ei[] = {
+	{
+		.data_type	= QMI_DATA_LEN,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= DATA_REQ1_TLV_TYPE,
+		.offset		= offsetof(struct test_data_req_msg_v01,
+					   data_len),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= TEST_MED_DATA_SIZE_V01,
+		.elem_size	= sizeof(u8),
+		.array_type	= VAR_LEN_ARRAY,
+		.tlv_type	= DATA_REQ1_TLV_TYPE,
+		.offset		= offsetof(struct test_data_req_msg_v01,
+					   data),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= DATA_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_data_req_msg_v01,
+					   client_name_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct test_name_type_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= DATA_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_data_req_msg_v01,
+					   client_name),
+		.ei_array	= test_name_type_v01_ei,
+	},
+	{}
+};
+
+struct test_data_resp_msg_v01 {
+	struct qmi_response_type_v01 resp;
+
+	u8 data_valid;
+	u32 data_len;
+	u8 data[TEST_MED_DATA_SIZE_V01];
+
+	u8 service_name_valid;
+	struct test_name_type_v01 service_name;
+};
+
+static struct qmi_elem_info test_data_resp_msg_v01_ei[] = {
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct qmi_response_type_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= DATA_RESP1_TLV_TYPE,
+		.offset		= offsetof(struct test_data_resp_msg_v01,
+					   resp),
+		.ei_array	= qmi_response_type_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= DATA_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_data_resp_msg_v01,
+					   data_valid),
+	},
+	{
+		.data_type	= QMI_DATA_LEN,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= DATA_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_data_resp_msg_v01,
+					   data_len),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= TEST_MED_DATA_SIZE_V01,
+		.elem_size	= sizeof(u8),
+		.array_type	= VAR_LEN_ARRAY,
+		.tlv_type	= DATA_OPT1_TLV_TYPE,
+		.offset		= offsetof(struct test_data_resp_msg_v01,
+					   data),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= DATA_OPT2_TLV_TYPE,
+		.offset		= offsetof(struct test_data_resp_msg_v01,
+					   service_name_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct test_name_type_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= DATA_OPT2_TLV_TYPE,
+		.offset		= offsetof(struct test_data_resp_msg_v01,
+					   service_name),
+		.ei_array	= test_name_type_v01_ei,
+	},
+	{}
+};
+
+/*
+ * ping_write() - ping_pong debugfs file write handler
+ * @file:	debugfs file context
+ * @user_buf:	reference to the user data (ignored)
+ * @count:	number of bytes in @user_buf
+ * @ppos:	offset in @file to write
+ *
+ * This function allows user space to send out a ping_pong QMI encoded message
+ * to the associated remote test service and will return with the result of the
+ * transaction. It serves as an example of how to provide a custom response
+ * handler.
+ *
+ * Return: @count, or negative errno on failure.
+ */
+static ssize_t ping_write(struct file *file, const char __user *user_buf,
+			  size_t count, loff_t *ppos)
+{
+	struct qmi_handle *qmi = file->private_data;
+	struct test_ping_req_msg_v01 req = {};
+	struct qmi_txn txn;
+	int ret;
+
+	memcpy(req.ping, "ping", sizeof(req.ping));
+
+	ret = qmi_txn_init(qmi, &txn, NULL, NULL);
+	if (ret < 0)
+		return ret;
+
+	ret = qmi_send_request(qmi, NULL, &txn,
+			       TEST_PING_REQ_MSG_ID_V01,
+			       TEST_PING_REQ_MAX_MSG_LEN_V01,
+			       test_ping_req_msg_v01_ei, &req);
+	if (ret < 0) {
+		qmi_txn_cancel(&txn);
+		return ret;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);
+	if (ret < 0)
+		count = ret;
+
+	return count;
+}
+
+static const struct file_operations ping_fops = {
+	.open = simple_open,
+	.write = ping_write,
+};
+
+static void ping_pong_cb(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			 struct qmi_txn *txn, const void *data)
+{
+	const struct test_ping_resp_msg_v01 *resp = data;
+
+	if (!txn) {
+		pr_err("spurious ping response\n");
+		return;
+	}
+
+	if (resp->resp.result == QMI_RESULT_FAILURE_V01)
+		txn->result = -ENXIO;
+	else if (!resp->pong_valid || memcmp(resp->pong, "pong", 4))
+		txn->result = -EINVAL;
+
+	complete(&txn->completion);
+}
+
+/*
+ * data_write() - data debugfs file write handler
+ * @file:	debugfs file context
+ * @user_buf:	reference to the user data
+ * @count:	number of bytes in @user_buf
+ * @ppos:	offset in @file to write
+ *
+ * This function allows user space to send out a data QMI encoded message to
+ * the associated remote test service and will return with the result of the
+ * transaction. It serves as an example of how to have the QMI helpers decode a
+ * transaction response into a provided object automatically.
+ *
+ * Return: @count, or negative errno on failure.
+ */
+static ssize_t data_write(struct file *file, const char __user *user_buf,
+			  size_t count, loff_t *ppos)
+
+{
+	struct qmi_handle *qmi = file->private_data;
+	struct test_data_resp_msg_v01 *resp;
+	struct test_data_req_msg_v01 *req;
+	struct qmi_txn txn;
+	int ret;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	resp = kzalloc(sizeof(*resp), GFP_KERNEL);
+	if (!resp) {
+		kfree(req);
+		return -ENOMEM;
+	}
+
+	req->data_len = min_t(size_t, sizeof(req->data), count);
+	if (copy_from_user(req->data, user_buf, req->data_len)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	ret = qmi_txn_init(qmi, &txn, test_data_resp_msg_v01_ei, resp);
+	if (ret < 0)
+		goto out;
+
+	ret = qmi_send_request(qmi, NULL, &txn,
+			       TEST_DATA_REQ_MSG_ID_V01,
+			       TEST_DATA_REQ_MAX_MSG_LEN_V01,
+			       test_data_req_msg_v01_ei, req);
+	if (ret < 0) {
+		qmi_txn_cancel(&txn);
+		goto out;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);
+	if (ret < 0) {
+		goto out;
+	} else if (!resp->data_valid ||
+		   resp->data_len != req->data_len ||
+		   memcmp(resp->data, req->data, req->data_len)) {
+		pr_err("response data doesn't match expectation\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = count;
+
+out:
+	kfree(resp);
+	kfree(req);
+
+	return ret;
+}
+
+static const struct file_operations data_fops = {
+	.open = simple_open,
+	.write = data_write,
+};
+
+static struct qmi_msg_handler qmi_sample_handlers[] = {
+	{
+		.type = QMI_RESPONSE,
+		.msg_id = TEST_PING_REQ_MSG_ID_V01,
+		.ei = test_ping_resp_msg_v01_ei,
+		.decoded_size = sizeof(struct test_ping_req_msg_v01),
+		.fn = ping_pong_cb
+	},
+	{}
+};
+
+struct qmi_sample {
+	struct qmi_handle qmi;
+
+	struct dentry *de_dir;
+	struct dentry *de_data;
+	struct dentry *de_ping;
+};
+
+static struct dentry *qmi_debug_dir;
+
+static int qmi_sample_probe(struct platform_device *pdev)
+{
+	struct sockaddr_qrtr *sq;
+	struct qmi_sample *sample;
+	char path[20];
+	int ret;
+
+	sample = devm_kzalloc(&pdev->dev, sizeof(*sample), GFP_KERNEL);
+	if (!sample)
+		return -ENOMEM;
+
+	ret = qmi_handle_init(&sample->qmi, TEST_DATA_REQ_MAX_MSG_LEN_V01,
+			      NULL,
+			      qmi_sample_handlers);
+	if (ret < 0)
+		return ret;
+
+	sq = dev_get_platdata(&pdev->dev);
+	ret = kernel_connect(sample->qmi.sock, (struct sockaddr *)sq,
+			     sizeof(*sq), 0);
+	if (ret < 0) {
+		pr_err("failed to connect to remote service port\n");
+		goto err_release_qmi_handle;
+	}
+
+	snprintf(path, sizeof(path), "%d:%d", sq->sq_node, sq->sq_port);
+
+	sample->de_dir = debugfs_create_dir(path, qmi_debug_dir);
+	if (IS_ERR(sample->de_dir)) {
+		ret = PTR_ERR(sample->de_dir);
+		goto err_release_qmi_handle;
+	}
+
+	sample->de_data = debugfs_create_file("data", 0600, sample->de_dir,
+					      sample, &data_fops);
+	if (IS_ERR(sample->de_data)) {
+		ret = PTR_ERR(sample->de_data);
+		goto err_remove_de_dir;
+	}
+
+	sample->de_ping = debugfs_create_file("ping", 0600, sample->de_dir,
+					      sample, &ping_fops);
+	if (IS_ERR(sample->de_ping)) {
+		ret = PTR_ERR(sample->de_ping);
+		goto err_remove_de_data;
+	}
+
+	platform_set_drvdata(pdev, sample);
+
+	return 0;
+
+err_remove_de_data:
+	debugfs_remove(sample->de_data);
+err_remove_de_dir:
+	debugfs_remove(sample->de_dir);
+err_release_qmi_handle:
+	qmi_handle_release(&sample->qmi);
+
+	return ret;
+}
+
+static int qmi_sample_remove(struct platform_device *pdev)
+{
+	struct qmi_sample *sample = platform_get_drvdata(pdev);
+
+	debugfs_remove(sample->de_ping);
+	debugfs_remove(sample->de_data);
+	debugfs_remove(sample->de_dir);
+
+	qmi_handle_release(&sample->qmi);
+
+	return 0;
+}
+
+static struct platform_driver qmi_sample_driver = {
+	.probe = qmi_sample_probe,
+	.remove = qmi_sample_remove,
+	.driver = {
+		.name = "qmi_sample_client",
+	},
+};
+
+static int qmi_sample_new_server(struct qmi_handle *qmi,
+				 struct qmi_service *service)
+{
+	struct platform_device *pdev;
+	struct sockaddr_qrtr sq = { AF_QIPCRTR, service->node, service->port };
+	int ret;
+
+	pdev = platform_device_alloc("qmi_sample_client", PLATFORM_DEVID_AUTO);
+	if (!pdev)
+		return -ENOMEM;
+
+	ret = platform_device_add_data(pdev, &sq, sizeof(sq));
+	if (ret)
+		goto err_put_device;
+
+	ret = platform_device_add(pdev);
+	if (ret)
+		goto err_put_device;
+
+	service->priv = pdev;
+
+	return 0;
+
+err_put_device:
+	platform_device_put(pdev);
+
+	return ret;
+}
+
+static void qmi_sample_del_server(struct qmi_handle *qmi,
+				  struct qmi_service *service)
+{
+	struct platform_device *pdev = service->priv;
+
+	platform_device_unregister(pdev);
+}
+
+static struct qmi_handle lookup_client;
+
+static struct qmi_ops lookup_ops = {
+	.new_server = qmi_sample_new_server,
+	.del_server = qmi_sample_del_server,
+};
+
+static int qmi_sample_init(void)
+{
+	int ret;
+
+	qmi_debug_dir = debugfs_create_dir("qmi_sample", NULL);
+	if (IS_ERR(qmi_debug_dir)) {
+		pr_err("failed to create qmi_sample dir\n");
+		return PTR_ERR(qmi_debug_dir);
+	}
+
+	ret = platform_driver_register(&qmi_sample_driver);
+	if (ret)
+		goto err_remove_debug_dir;
+
+	ret = qmi_handle_init(&lookup_client, 0, &lookup_ops, NULL);
+	if (ret < 0)
+		goto err_unregister_driver;
+
+	qmi_add_lookup(&lookup_client, 15, 0, 0);
+
+	return 0;
+
+err_unregister_driver:
+	platform_driver_unregister(&qmi_sample_driver);
+err_remove_debug_dir:
+	debugfs_remove(qmi_debug_dir);
+
+	return ret;
+}
+
+static void qmi_sample_exit(void)
+{
+	qmi_handle_release(&lookup_client);
+
+	platform_driver_unregister(&qmi_sample_driver);
+
+	debugfs_remove(qmi_debug_dir);
+}
+
+module_init(qmi_sample_init);
+module_exit(qmi_sample_exit);
+
+MODULE_DESCRIPTION("Sample QMI client driver");
+MODULE_LICENSE("GPL v2");
-- 
2.15.0