2 files changed, 150 insertions, 0 deletions
diff --git a/meta-rtmod1/model_answer/files/rt-demo-kmod.c b/meta-rtmod1/model_answer/files/rt-demo-kmod.c
new file mode 100644
index 0000000000..2342b9c35e
--- /dev/null
+++ b/meta-rtmod1/model_answer/files/rt-demo-kmod.c
@@ -0,0 +1,98 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+
+struct demo_attr {
+	struct attribute attr;
+	int value;
+};
+
+static struct demo_attr notify = {
+	.attr.name="notify",
+	.attr.mode = 0644,
+	.value = 0,
+};
+
+static struct demo_attr trigger = {
+	.attr.name="trigger",
+	.attr.mode = 0644,
+	.value = 0,
+};
+
+static struct attribute *demoattr[] = {
+	&notify.attr,
+	&trigger.attr,
+	NULL
+};
+
+static struct kobject *demo_kobj;
+
+static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
+{
+	struct demo_attr *a = container_of(attr, struct demo_attr, attr);
+
+	pr_debug("RT demo kmod: show called (%s)\n", a->attr.name);
+
+	return scnprintf(buf, PAGE_SIZE, "%s: %d\n", a->attr.name, a->value);
+}
+
+static ssize_t store(struct kobject *kobj, struct attribute *attr,
+	       	     const char *buf, size_t len)
+{
+	struct demo_attr *a = container_of(attr, struct demo_attr, attr);
+
+	if (!strncmp(a->attr.name, "notify", sizeof("notify")))
+		return len;
+
+	sscanf(buf, "%d", &a->value);
+	notify.value = a->value;
+	pr_debug("RT demo kmod: sysfs_notify store %s = %d\n", a->attr.name,
+	       a->value);
+	sysfs_notify(demo_kobj, NULL, "notify");
+
+	return len;
+}
+
+static struct sysfs_ops demoops = {
+	.show = show,
+	.store = store,
+};
+
+static struct kobj_type mytype = {
+	.sysfs_ops = &demoops,
+	.default_attrs = demoattr,
+};
+
+static int __init demo_module_init(void)
+{
+	int err = -1;
+
+	pr_debug("RT demo kmod: init\n");
+	demo_kobj = kzalloc(sizeof(*demo_kobj), GFP_KERNEL);
+	if (demo_kobj) {
+		kobject_init(demo_kobj, &mytype);
+		if (kobject_add(demo_kobj, NULL, "%s", "demo-poll")) {
+			err = -1;
+			pr_err("RT demo kmod: kobject_add() failed\n");
+			kobject_put(demo_kobj);
+			demo_kobj = NULL;
+		}
+		err = 0;
+	}
+	return err;
+}
+
+static void __exit demo_module_exit(void)
+{
+	if (demo_kobj) {
+		kobject_put(demo_kobj);
+		kfree(demo_kobj);
+	}
+	pr_debug("RT demo kmod: exit\n");
+}
+
+module_init(demo_module_init);
+module_exit(demo_module_exit);
+MODULE_LICENSE("GPL");
diff --git a/meta-rtmod1/model_answer/files/rt-sysfs-poll.c b/meta-rtmod1/model_answer/files/rt-sysfs-poll.c
new file mode 100644
index 0000000000..8d0a5314e9
--- /dev/null
+++ b/meta-rtmod1/model_answer/files/rt-sysfs-poll.c
@@ -0,0 +1,52 @@
+/*   Copyright (C) 2021 by Linaro */
+/*   Permission to use, copy, modify, and/or distribute this software for any */
+/*   purpose with or without fee is hereby granted. */
+/*   THE SOFTWARE IS PROVIDED AS IS AND THE AUTHOR DISCLAIMS ALL WARRANTIES */
+/*   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF */
+/*   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR */
+/*   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES */
+/*   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN */
+/*   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF */
+/*   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h> 
+#include <sys/stat.h> 
+#include <poll.h>
+
+#define TEST_SYSFS_NOTIFY	"/sys/demo-poll/notify"
+
+int main(void)
+{
+	int notify_fd, rv, cnt;
+	char attr_data[100];
+	struct pollfd ufds;
+
+	if ((notify_fd = open(TEST_SYSFS_NOTIFY, O_RDWR)) < 0) {
+		printf("Unable to open %s", TEST_SYSFS_NOTIFY);
+		exit(1);
+	}
+
+	cnt = read(notify_fd, attr_data, 100);
+	lseek(notify_fd, 0, SEEK_SET);
+	ufds.fd = notify_fd;
+	ufds.events = POLLPRI | POLLERR;
+	ufds.revents = 0;
+
+	if ((rv = poll(&ufds, 1, 100000)) < 0) {
+		perror("poll error");
+	} else if (rv == 0) {
+		printf("Timeout occurred!\n");
+	} else if (ufds.revents & (POLLPRI | POLLERR)) {
+		cnt = read(notify_fd, attr_data, 100);
+		printf("sysfs_notify() triggered, revents: %08X,"
+		       " attribute data[%d] %s", ufds.revents, cnt, attr_data);
+	}
+
+	close(notify_fd);
+}