schulung_tools: drivers: remove modules subdir

There is no need for the extra directory level. Move all the
example modules to the parent "drivers" directory and delete
the modules directory.

Signed-off-by: John Ogness <john.ogness@linutronix.de>

12 files changed, 1279 insertions, 0 deletions

diff --git a/schulung_tools/drivers/hellodriver/Makefile b/schulung_tools/drivers/hellodriver/Makefile
new file mode 100644
index 0000000..764fefd
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/Makefile
@@ -0,0 +1,19 @@
+MNAME = hello
+BDIR = /lib/modules/`uname -r`/build
+
+ifeq ($(KERNELRELEASE),)
+# called from shell
+
+.PHONY: default clean
+
+default:
+	make -C $(BDIR) M=$(shell pwd) modules
+
+clean:
+	rm -rf $(MNAME).mod.* $(MNAME).*o .$(MNAME)* .tmp* Module.symvers modules.order
+
+else
+# called from kernel Makefile
+
+	obj-m := $(MNAME).o
+endif
diff --git a/schulung_tools/drivers/hellodriver/hello.c b/schulung_tools/drivers/hellodriver/hello.c
new file mode 100644
index 0000000..7f78d06
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/hello.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/cdev.h>
+#include <linux/of.h>
+
+struct hello_dev {
+	struct device *dev;
+	struct cdev cdev;
+	unsigned int minor;
+};
+
+#define HELLO_MAX_DEVICES 10
+
+static struct class *hello_class;
+static dev_t hello_devt;
+
+static int hello_open(struct inode *node, struct file *f)
+{
+	struct cdev *cd = node->i_cdev;
+	struct hello_dev *hello = container_of(cd, struct hello_dev, cdev);
+	dev_info(hello->dev, "%s\n", __func__);
+	f->private_data = hello;
+	return 0;
+}
+
+static int hello_release(struct inode *node, struct file *f)
+{
+	struct hello_dev *hello = f->private_data;
+	dev_info(hello->dev, "%s\n", __func__);
+	f->private_data = NULL;
+	return 0;
+}
+
+static ssize_t hello_read(struct file *f, char __user *u, size_t s, loff_t *l)
+{
+	struct hello_dev *hello = f->private_data;
+	char buf[10];
+	size_t len;
+
+	dev_info(hello->dev, "%s: size=%zu offset=%llu\n", __func__, s, *l);
+
+	if (*l >= 40)
+		return 0;
+
+	len = snprintf(buf, sizeof(buf), "hello:%d\n", hello->minor);
+
+	if (s < len)
+		len = s;
+
+	if (copy_to_user(u, buf, len) != 0)
+		return -EFAULT;
+
+	*l += len;
+
+	return len;
+}
+
+static ssize_t hello_write(struct file *f, const char __user *u, size_t s,
+			   loff_t *l)
+{
+	struct hello_dev *hello = f->private_data;
+	dev_info(hello->dev, "%s: size=%zu offset=%llu\n", __func__, s, *l);
+	return s;
+}
+
+static const struct file_operations hello_fops = {
+	.owner = THIS_MODULE,
+	.open = hello_open,
+	.release = hello_release,
+	.read = hello_read,
+	.write = hello_write,
+};
+
+static int hello_probe(struct platform_device *pdev)
+{
+	struct hello_dev *hello;
+	struct device *dev;
+	dev_t devt;
+	int ret;
+
+	hello = devm_kzalloc(&pdev->dev, sizeof(*hello), GFP_KERNEL);
+	if (!hello) {
+		dev_err(&pdev->dev, "devm_kzalloc failed\n");
+		return -ENOMEM;
+	}
+
+#ifdef CONFIG_OF
+	ret = of_property_read_u32(pdev->dev.of_node, "index", &hello->minor);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no index specified\n");
+		goto err_out;
+	}
+#else
+	hello->minor = (unsigned)pdev->id;
+#endif
+
+	if (hello->minor >= HELLO_MAX_DEVICES) {
+		dev_err(&pdev->dev, "invalid index: %u\n", hello->minor);
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	hello->dev = &pdev->dev;
+	platform_set_drvdata(pdev, hello);
+
+	devt = MKDEV(MAJOR(hello_devt), hello->minor);
+
+	cdev_init(&hello->cdev, &hello_fops);
+	hello->cdev.owner = THIS_MODULE;
+	ret = cdev_add(&hello->cdev, devt, 1);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "cdev_add failed\n");
+		goto err_drvdata;
+	}
+
+	dev = device_create(hello_class, &pdev->dev, devt, hello,
+			    "hello%d", hello->minor);
+	if (IS_ERR(dev)) {
+		dev_err(&pdev->dev, "device_create failed\n");
+		ret = PTR_ERR(dev);
+		goto err_cdev;
+	}
+
+	dev_info(&pdev->dev, "HELLO! I am hello device %d!\n", hello->minor);
+
+	return 0;
+
+err_cdev:
+	cdev_del(&hello->cdev);
+err_drvdata:
+	platform_set_drvdata(pdev, NULL);
+err_out:
+	return ret;
+}
+
+static int hello_remove(struct platform_device *pdev)
+{
+	struct hello_dev *hello = platform_get_drvdata(pdev);
+
+	device_destroy(hello_class, MKDEV(MAJOR(hello_devt), hello->minor));
+	cdev_del(&hello->cdev);
+	platform_set_drvdata(pdev, NULL);
+
+	dev_info(&pdev->dev, "GOODBYE! I was hello device %d!\n", hello->minor);
+
+	return 0;
+}
+
+static const struct of_device_id hello_match[] = {
+	{ .compatible = "virtual,hello", },
+	{ /* end of table */ }
+};
+
+static struct platform_driver hello_driver = {
+	.driver = {
+		.name = "hello",
+		.of_match_table = hello_match,
+	},
+	.probe = hello_probe,
+	.remove = hello_remove,
+};
+
+#ifndef CONFIG_OF
+static struct platform_device *pdevs[3];
+#endif
+
+static int __init hello_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "%s\n", __func__);
+
+	ret = alloc_chrdev_region(&hello_devt, 0, HELLO_MAX_DEVICES, "hello");
+	if (ret < 0)
+		return ret;
+
+	hello_class = class_create(THIS_MODULE, "hello");
+	if (IS_ERR(hello_class)) {
+		printk(KERN_ERR "%s: failed to create class\n", __func__);
+		ret = PTR_ERR(hello_class);
+		goto err_region;
+	}
+
+	ret = platform_driver_register(&hello_driver);
+	if (ret != 0)
+		goto err_class;
+
+#ifndef CONFIG_OF
+	pdevs[0] = platform_device_register_simple("hello", 1, NULL, 0);
+	pdevs[1] = platform_device_register_simple("hello", 3, NULL, 0);
+	pdevs[2] = platform_device_register_simple("hello", 5, NULL, 0);
+#endif
+
+	return 0;
+
+err_class:
+	class_destroy(hello_class);
+err_region:
+	unregister_chrdev_region(hello_devt, HELLO_MAX_DEVICES);
+	return ret;
+}
+
+static void __exit hello_exit(void)
+{
+	printk(KERN_INFO "%s\n", __func__);
+
+#ifndef CONFIG_OF
+	platform_device_unregister(pdevs[0]);
+	platform_device_unregister(pdevs[1]);
+	platform_device_unregister(pdevs[2]);
+#endif
+
+	platform_driver_unregister(&hello_driver);
+	class_destroy(hello_class);
+	unregister_chrdev_region(hello_devt, HELLO_MAX_DEVICES);
+}
+
+module_init(hello_init);
+module_exit(hello_exit);
+
+MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>");
+MODULE_DESCRIPTION("a great module for hello-ing!");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("20190101");
diff --git a/schulung_tools/drivers/hellodriver/patch-add-sysfs.diff b/schulung_tools/drivers/hellodriver/patch-add-sysfs.diff
new file mode 100644
index 0000000..44c913e
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patch-add-sysfs.diff
@@ -0,0 +1,57 @@
+From 9ec20c5b243d6f1f83b38b57474cf532c4575a02 Mon Sep 17 00:00:00 2001
+From: John Ogness <john.ogness@linutronix.de>
+Date: Fri, 15 Feb 2019 12:58:25 +0106
+Subject: [PATCH] hello: add custom sysfs files
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+---
+ hello.c | 26 ++++++++++++++++++++++
+ 1 file changed, 26 insertions(+)
+
+diff --git a/hello.c b/hello.c
+index 7f78d06..4c7989a 100644
+--- a/hello.c
++++ b/hello.c
+@@ -77,6 +77,30 @@ static const struct file_operations hello_fops = {
+ 	.write = hello_write,
+ };
+ 
++static ssize_t major_show(struct device *dev,
++			  struct device_attribute *attr, char *buf)
++{
++	return sprintf(buf, "%d\n", MAJOR(hello_devt));
++}
++static DEVICE_ATTR_RO(major);
++
++static ssize_t minor_show(struct device *dev,
++			  struct device_attribute *attr, char *buf)
++{
++	struct platform_device *pdev = to_platform_device(dev);
++	struct hello_dev *hello = platform_get_drvdata(pdev);
++
++	return sprintf(buf, "%d\n", hello->minor);
++}
++static DEVICE_ATTR_RO(minor);
++
++static struct attribute *hello_device_attrs[] = {
++        &dev_attr_major.attr,
++        &dev_attr_minor.attr,
++        NULL,
++};
++ATTRIBUTE_GROUPS(hello_device);
++
+ static int hello_probe(struct platform_device *pdev)
+ {
+ 	struct hello_dev *hello;
+@@ -187,6 +211,8 @@ static int __init hello_init(void)
+ 		goto err_region;
+ 	}
+ 
++	hello_class->dev_groups = hello_device_groups;
++
+ 	ret = platform_driver_register(&hello_driver);
+ 	if (ret != 0)
+ 		goto err_class;
+-- 
+2.1.4
+
diff --git a/schulung_tools/drivers/hellodriver/patch-hello-dts.diff b/schulung_tools/drivers/hellodriver/patch-hello-dts.diff
new file mode 100644
index 0000000..2d0bf52
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patch-hello-dts.diff
@@ -0,0 +1,26 @@
+diff --git a/arch/arm/boot/dts/vexpress-v2p-ca9.dts b/arch/arm/boot/dts/vexpress-v2p-ca9.dts
+index d949fac..4952799 100644
+--- a/arch/arm/boot/dts/vexpress-v2p-ca9.dts
++++ b/arch/arm/boot/dts/vexpress-v2p-ca9.dts
+@@ -132,6 +132,21 @@
+ 		status = "disabled";
+ 	};
+ 
++	hello@1 {
++		compatible = "virtual,hello";
++		index = <1>;
++	};
++
++	hello@5 {
++		compatible = "virtual,hello";
++		index = <5>;
++	};
++
++	hello@8 {
++		compatible = "virtual,hello";
++		index = <8>;
++	};
++
+ 	watchdog@100e5000 {
+ 		compatible = "arm,sp805", "arm,primecell";
+ 		reg = <0x100e5000 0x1000>;
diff --git a/schulung_tools/drivers/hellodriver/patch-kernel-build.diff b/schulung_tools/drivers/hellodriver/patch-kernel-build.diff
new file mode 100644
index 0000000..8d43ca7
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patch-kernel-build.diff
@@ -0,0 +1,32 @@
+diff -urNp a/drivers/char/Kconfig b/drivers/char/Kconfig
+--- a/drivers/char/Kconfig	2016-05-16 00:43:13.000000000 +0200
++++ b/drivers/char/Kconfig	2016-06-08 20:41:14.047205734 +0200
+@@ -6,6 +6,16 @@ menu "Character devices"
+ 
+ source "drivers/tty/Kconfig"
+ 
++config HELLO
++	tristate "hello demo driver"
++	default n
++	help
++	  This driver demonstrates how to create a platform device that is
++	  specified in a device tree.
++
++	  It also create a character device to demonstrate how a character
++	  device interface can be provided to userspace.
++
+ config DEVMEM
+ 	bool "/dev/mem virtual device support"
+ 	default y
+diff -urNp a/drivers/char/Makefile b/drivers/char/Makefile
+--- a/drivers/char/Makefile	2016-05-16 00:43:13.000000000 +0200
++++ b/drivers/char/Makefile	2016-06-08 14:16:44.897437533 +0200
+@@ -16,6 +16,8 @@ obj-$(CONFIG_IBM_BSR)		+= bsr.o
+ obj-$(CONFIG_SGI_MBCS)		+= mbcs.o
+ obj-$(CONFIG_BFIN_OTP)		+= bfin-otp.o
+ 
++obj-$(CONFIG_HELLO)		+= hello.o
++
+ obj-$(CONFIG_PRINTER)		+= lp.o
+ 
+ obj-$(CONFIG_APM_EMULATION)	+= apm-emulation.o
diff --git a/schulung_tools/drivers/hellodriver/patches-leds/0001-hello-change-from-platform-to-pci-bus.patch b/schulung_tools/drivers/hellodriver/patches-leds/0001-hello-change-from-platform-to-pci-bus.patch
new file mode 100644
index 0000000..35dc817
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patches-leds/0001-hello-change-from-platform-to-pci-bus.patch
@@ -0,0 +1,185 @@
+From 28357d61e0ec39851ca88a09b04ce876b8758448 Mon Sep 17 00:00:00 2001
+From: John Ogness <john.ogness@linutronix.de>
+Date: Fri, 15 Feb 2019 12:11:27 +0100
+Subject: [PATCH 2/7] hello: change from platform to pci bus
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+---
+ hello.c | 89 +++++++++++++++++++++++++++++++----------------------------------
+ 1 file changed, 43 insertions(+), 46 deletions(-)
+
+diff --git a/hello.c b/hello.c
+index 7f78d06..db50302 100644
+--- a/hello.c
++++ b/hello.c
+@@ -5,9 +5,8 @@
+ #include <linux/uaccess.h>
+ #include <linux/slab.h>
+ #include <linux/device.h>
+-#include <linux/platform_device.h>
++#include <linux/pci.h>
+ #include <linux/cdev.h>
+-#include <linux/of.h>
+ 
+ struct hello_dev {
+ 	struct device *dev;
+@@ -77,7 +76,7 @@ static const struct file_operations hello_fops = {
+ 	.write = hello_write,
+ };
+ 
+-static int hello_probe(struct platform_device *pdev)
++static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ {
+ 	struct hello_dev *hello;
+ 	struct device *dev;
+@@ -90,15 +89,7 @@ static int hello_probe(struct platform_device *pdev)
+ 		return -ENOMEM;
+ 	}
+ 
+-#ifdef CONFIG_OF
+-	ret = of_property_read_u32(pdev->dev.of_node, "index", &hello->minor);
+-	if (ret < 0) {
+-		dev_err(&pdev->dev, "no index specified\n");
+-		goto err_out;
+-	}
+-#else
+-	hello->minor = (unsigned)pdev->id;
+-#endif
++	hello->minor = 1;
+ 
+ 	if (hello->minor >= HELLO_MAX_DEVICES) {
+ 		dev_err(&pdev->dev, "invalid index: %u\n", hello->minor);
+@@ -107,7 +98,27 @@ static int hello_probe(struct platform_device *pdev)
+ 	}
+ 
+ 	hello->dev = &pdev->dev;
+-	platform_set_drvdata(pdev, hello);
++	pci_set_drvdata(pdev, hello);
++
++	ret = pci_enable_device(pdev);
++	if (ret) {
++		dev_err(&pdev->dev, "failed to enable device\n");
++		goto err_drvdata;
++	}
++
++	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
++		dev_err(&pdev->dev, "failed to find base address\n");
++		ret = -ENODEV;
++		goto err_enable;
++	}
++
++	ret = pci_request_regions(pdev, "hello");
++	if (ret) {
++		dev_err(&pdev->dev, "failed to request resources\n");
++		goto err_enable;
++	}
++
++	pci_set_master(pdev);
+ 
+ 	devt = MKDEV(MAJOR(hello_devt), hello->minor);
+ 
+@@ -116,7 +127,7 @@ static int hello_probe(struct platform_device *pdev)
+ 	ret = cdev_add(&hello->cdev, devt, 1);
+ 	if (ret != 0) {
+ 		dev_err(&pdev->dev, "cdev_add failed\n");
+-		goto err_drvdata;
++		goto err_regions;
+ 	}
+ 
+ 	dev = device_create(hello_class, &pdev->dev, devt, hello,
+@@ -133,43 +144,41 @@ static int hello_probe(struct platform_device *pdev)
+ 
+ err_cdev:
+ 	cdev_del(&hello->cdev);
++err_regions:
++	pci_release_regions(pdev);
++err_enable:
++	pci_disable_device(pdev);
+ err_drvdata:
+-	platform_set_drvdata(pdev, NULL);
+-err_out:
++	pci_set_drvdata(pdev, NULL);
+ 	return ret;
+ }
+ 
+-static int hello_remove(struct platform_device *pdev)
++static void hello_remove(struct pci_dev *pdev)
+ {
+-	struct hello_dev *hello = platform_get_drvdata(pdev);
++	struct hello_dev *hello = pci_get_drvdata(pdev);
+ 
+ 	device_destroy(hello_class, MKDEV(MAJOR(hello_devt), hello->minor));
+ 	cdev_del(&hello->cdev);
+-	platform_set_drvdata(pdev, NULL);
++	pci_release_regions(pdev);
++	pci_disable_device(pdev);
++	pci_set_drvdata(pdev, NULL);
+ 
+ 	dev_info(&pdev->dev, "GOODBYE! I was hello device %d!\n", hello->minor);
+-
+-	return 0;
+ }
+ 
+-static const struct of_device_id hello_match[] = {
+-	{ .compatible = "virtual,hello", },
++static const struct pci_device_id hello_id_table[] = {
++	{ 0x1af4, 0x1110, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0 },
+ 	{ /* end of table */ }
+ };
++MODULE_DEVICE_TABLE(pci, hello_id_table);
+ 
+-static struct platform_driver hello_driver = {
+-	.driver = {
+-		.name = "hello",
+-		.of_match_table = hello_match,
+-	},
++static struct pci_driver hello_driver = {
++	.name = "hello",
++	.id_table = hello_id_table,
+ 	.probe = hello_probe,
+ 	.remove = hello_remove,
+ };
+ 
+-#ifndef CONFIG_OF
+-static struct platform_device *pdevs[3];
+-#endif
+-
+ static int __init hello_init(void)
+ {
+ 	int ret;
+@@ -187,16 +196,10 @@ static int __init hello_init(void)
+ 		goto err_region;
+ 	}
+ 
+-	ret = platform_driver_register(&hello_driver);
++	ret = pci_register_driver(&hello_driver);
+ 	if (ret != 0)
+ 		goto err_class;
+ 
+-#ifndef CONFIG_OF
+-	pdevs[0] = platform_device_register_simple("hello", 1, NULL, 0);
+-	pdevs[1] = platform_device_register_simple("hello", 3, NULL, 0);
+-	pdevs[2] = platform_device_register_simple("hello", 5, NULL, 0);
+-#endif
+-
+ 	return 0;
+ 
+ err_class:
+@@ -210,13 +213,7 @@ static void __exit hello_exit(void)
+ {
+ 	printk(KERN_INFO "%s\n", __func__);
+ 
+-#ifndef CONFIG_OF
+-	platform_device_unregister(pdevs[0]);
+-	platform_device_unregister(pdevs[1]);
+-	platform_device_unregister(pdevs[2]);
+-#endif
+-
+-	platform_driver_unregister(&hello_driver);
++	pci_unregister_driver(&hello_driver);
+ 	class_destroy(hello_class);
+ 	unregister_chrdev_region(hello_devt, HELLO_MAX_DEVICES);
+ }
+-- 
+2.11.0
+
diff --git a/schulung_tools/drivers/hellodriver/patches-leds/0002-hello-add-pci-memory-mapping.patch b/schulung_tools/drivers/hellodriver/patches-leds/0002-hello-add-pci-memory-mapping.patch
new file mode 100644
index 0000000..0a11a57
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patches-leds/0002-hello-add-pci-memory-mapping.patch
@@ -0,0 +1,64 @@
+From 3afec946845a02a8fce94d00abda9b4c8abcbce0 Mon Sep 17 00:00:00 2001
+From: John Ogness <john.ogness@linutronix.de>
+Date: Fri, 15 Feb 2019 11:03:59 +0106
+Subject: [PATCH 3/7] hello: add pci memory mapping
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+---
+ hello.c | 12 +++++++++++-
+ 1 file changed, 11 insertions(+), 1 deletion(-)
+
+diff --git a/hello.c b/hello.c
+index db50302..58a64e5 100644
+--- a/hello.c
++++ b/hello.c
+@@ -12,6 +12,7 @@ struct hello_dev {
+ 	struct device *dev;
+ 	struct cdev cdev;
+ 	unsigned int minor;
++	void __iomem *mem;
+ };
+ 
+ #define HELLO_MAX_DEVICES 10
+@@ -120,6 +121,12 @@ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ 
+ 	pci_set_master(pdev);
+ 
++	hello->mem = pci_iomap(pdev, 2, 0);
++	if (!hello->mem) {
++		ret = -ENOMEM;
++		goto err_regions;
++	}
++
+ 	devt = MKDEV(MAJOR(hello_devt), hello->minor);
+ 
+ 	cdev_init(&hello->cdev, &hello_fops);
+@@ -127,7 +134,7 @@ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ 	ret = cdev_add(&hello->cdev, devt, 1);
+ 	if (ret != 0) {
+ 		dev_err(&pdev->dev, "cdev_add failed\n");
+-		goto err_regions;
++		goto err_iomap;
+ 	}
+ 
+ 	dev = device_create(hello_class, &pdev->dev, devt, hello,
+@@ -144,6 +151,8 @@ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ 
+ err_cdev:
+ 	cdev_del(&hello->cdev);
++err_iomap:
++	pci_iounmap(pdev, hello->mem);
+ err_regions:
+ 	pci_release_regions(pdev);
+ err_enable:
+@@ -159,6 +168,7 @@ static void hello_remove(struct pci_dev *pdev)
+ 
+ 	device_destroy(hello_class, MKDEV(MAJOR(hello_devt), hello->minor));
+ 	cdev_del(&hello->cdev);
++	pci_iounmap(pdev, hello->mem);
+ 	pci_release_regions(pdev);
+ 	pci_disable_device(pdev);
+ 	pci_set_drvdata(pdev, NULL);
+-- 
+2.11.0
+
diff --git a/schulung_tools/drivers/hellodriver/patches-leds/0003-hello-add-led-toggling-via-chardev-read-write.patch b/schulung_tools/drivers/hellodriver/patches-leds/0003-hello-add-led-toggling-via-chardev-read-write.patch
new file mode 100644
index 0000000..8f81e39
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patches-leds/0003-hello-add-led-toggling-via-chardev-read-write.patch
@@ -0,0 +1,56 @@
+From c7a4c4448632af43383818654dd79d2251b27e3e Mon Sep 17 00:00:00 2001
+From: John Ogness <john.ogness@linutronix.de>
+Date: Fri, 15 Feb 2019 11:04:56 +0106
+Subject: [PATCH 4/7] hello: add led toggling via chardev read/write
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+---
+ hello.c | 28 +++++++++++++++++++++++++++-
+ 1 file changed, 27 insertions(+), 1 deletion(-)
+
+diff --git a/hello.c b/hello.c
+index 58a64e5..f664121 100644
+--- a/hello.c
++++ b/hello.c
+@@ -61,11 +61,37 @@ static ssize_t hello_read(struct file *f, char __user *u, size_t s, loff_t *l)
+ 	return len;
+ }
+ 
++static void toggle_led(struct hello_dev *hello, int offset)
++{
++	if (readb(hello->mem + offset))
++		writeb(0, hello->mem + offset);
++	else
++		writeb(0xff, hello->mem + offset);
++}
++
+ static ssize_t hello_write(struct file *f, const char __user *u, size_t s,
+ 			   loff_t *l)
+ {
+ 	struct hello_dev *hello = f->private_data;
+-	dev_info(hello->dev, "%s: size=%zu offset=%llu\n", __func__, s, *l);
++	size_t sz = s;
++	char buf[32];
++
++	if (sz >= sizeof(buf))
++		sz = sizeof(buf) - 1;
++	if (copy_from_user(buf, u, sz) != 0)
++		return -EFAULT;
++	buf[sz] = 0;
++
++	dev_info(hello->dev, "%s: size=%zu offset=%llu buf=%s\n", __func__,
++		 s, *l, buf);
++
++	if (strstarts(buf, "heartbeat"))
++		toggle_led(hello, 0);
++	else if (strstarts(buf, "net"))
++		toggle_led(hello, 1);
++	else if (strstarts(buf, "disk"))
++		toggle_led(hello, 2);
++
+ 	return s;
+ }
+ 
+-- 
+2.11.0
+
diff --git a/schulung_tools/drivers/hellodriver/patches-leds/0004-hello-add-led-toggling-via-chardev-ioctl.patch b/schulung_tools/drivers/hellodriver/patches-leds/0004-hello-add-led-toggling-via-chardev-ioctl.patch
new file mode 100644
index 0000000..a67bf98
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patches-leds/0004-hello-add-led-toggling-via-chardev-ioctl.patch
@@ -0,0 +1,124 @@
+From be59ddb43fbf039ed0bc848ac56b7f72f7a619c8 Mon Sep 17 00:00:00 2001
+From: John Ogness <john.ogness@linutronix.de>
+Date: Fri, 15 Feb 2019 11:07:10 +0106
+Subject: [PATCH 5/7] hello: add led toggling via chardev ioctl
+
+Compile userspace application with:
+
+$ gcc -Wall -Werror hello-led.c -ohello-led
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+---
+ hello-led.c | 38 ++++++++++++++++++++++++++++++++++++++
+ hello.c     | 22 ++++++++++++++++++++++
+ hello.h     |  7 +++++++
+ 3 files changed, 67 insertions(+)
+ create mode 100644 hello-led.c
+ create mode 100644 hello.h
+
+diff --git a/hello-led.c b/hello-led.c
+new file mode 100644
+index 0000000..43230cd
+--- /dev/null
++++ b/hello-led.c
+@@ -0,0 +1,38 @@
++#include <stdio.h>
++#include <string.h>
++#include <errno.h>
++#include <fcntl.h>
++#include <unistd.h>
++#include <sys/ioctl.h>
++#include <sys/types.h>
++#include <sys/stat.h>
++#include "hello.h"
++
++int main(int argc, char *argv[])
++{
++	int fd;
++
++	if (argc != 3) {
++		fprintf(stderr, "usage: %s <device> <led>\n", argv[0]);
++		return 1;
++	}
++
++	fd = open(argv[1], O_RDWR);
++	if (fd < 0) {
++		fprintf(stderr, "open() failed: %s\n", strerror(errno));
++		return 1;
++	}
++
++	if (strcmp(argv[2], "heartbeat") == 0)
++		ioctl(fd, HELLO_IOCTL_TOGGLE_LED, 0);
++	else if (strcmp(argv[2], "net") == 0)
++		ioctl(fd, HELLO_IOCTL_TOGGLE_LED, 1);
++	else if (strcmp(argv[2], "disk") == 0)
++		ioctl(fd, HELLO_IOCTL_TOGGLE_LED, 2);
++	else
++		fprintf(stderr, "unknown led\n");
++
++	close(fd);
++
++	return 0;
++}
+diff --git a/hello.c b/hello.c
+index f664121..c42c75f 100644
+--- a/hello.c
++++ b/hello.c
+@@ -7,6 +7,7 @@
+ #include <linux/device.h>
+ #include <linux/pci.h>
+ #include <linux/cdev.h>
++#include "hello.h"
+ 
+ struct hello_dev {
+ 	struct device *dev;
+@@ -95,12 +96,33 @@ static ssize_t hello_write(struct file *f, const char __user *u, size_t s,
+ 	return s;
+ }
+ 
++static long hello_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
++{
++	struct hello_dev *hello = f->private_data;
++	u32 val;
++
++	dev_info(hello->dev, "%s: cmd=%u arg=%lu\n", __func__, cmd, arg);
++
++	switch (cmd) {
++	case HELLO_IOCTL_TOGGLE_LED:
++		val = arg;
++		if (val >= 0 && val <= 2)
++			toggle_led(hello, val);
++		break;
++	default:
++		return -EINVAL;
++	}
++
++	return 0;
++}
++
+ static const struct file_operations hello_fops = {
+ 	.owner = THIS_MODULE,
+ 	.open = hello_open,
+ 	.release = hello_release,
+ 	.read = hello_read,
+ 	.write = hello_write,
++	.unlocked_ioctl = hello_ioctl,
+ };
+ 
+ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+diff --git a/hello.h b/hello.h
+new file mode 100644
+index 0000000..cb172d9
+--- /dev/null
++++ b/hello.h
+@@ -0,0 +1,7 @@
++#ifndef HELLO_H
++#define HELLO_H
++
++#define HELLO_BASE		0x9F
++#define HELLO_IOCTL_TOGGLE_LED	_IOW(HELLO_BASE, 0x00, unsigned int)
++
++#endif /* HELLO_H */
+-- 
+2.11.0
+
diff --git a/schulung_tools/drivers/hellodriver/patches-leds/0005-hello-add-led-toggling-via-leds-subsystem.patch b/schulung_tools/drivers/hellodriver/patches-leds/0005-hello-add-led-toggling-via-leds-subsystem.patch
new file mode 100644
index 0000000..32f37ce
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patches-leds/0005-hello-add-led-toggling-via-leds-subsystem.patch
@@ -0,0 +1,142 @@
+From 3caece4ff394938f7544b994d35e784e2ce617cb Mon Sep 17 00:00:00 2001
+From: John Ogness <john.ogness@linutronix.de>
+Date: Fri, 15 Feb 2019 11:10:09 +0106
+Subject: [PATCH 6/7] hello: add led toggling via leds subsystem
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+---
+ hello.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 90 insertions(+)
+
+diff --git a/hello.c b/hello.c
+index c42c75f..f9809f3 100644
+--- a/hello.c
++++ b/hello.c
+@@ -7,6 +7,7 @@
+ #include <linux/device.h>
+ #include <linux/pci.h>
+ #include <linux/cdev.h>
++#include <linux/leds.h>
+ #include "hello.h"
+ 
+ struct hello_dev {
+@@ -14,6 +15,10 @@ struct hello_dev {
+ 	struct cdev cdev;
+ 	unsigned int minor;
+ 	void __iomem *mem;
++
++	struct led_classdev led_heartbeat;
++	struct led_classdev led_net;
++	struct led_classdev led_disk;
+ };
+ 
+ #define HELLO_MAX_DEVICES 10
+@@ -125,6 +130,67 @@ static const struct file_operations hello_fops = {
+ 	.unlocked_ioctl = hello_ioctl,
+ };
+ 
++static void set_brightness(struct hello_dev *hello, int offset,
++			   enum led_brightness b)
++{
++	if (b)
++		writeb(0xff, hello->mem + offset);
++	else
++		writeb(0, hello->mem + offset);
++}
++
++static enum led_brightness get_brightness(struct hello_dev *hello, int offset)
++{
++	if (readb(hello->mem + offset))
++		return 1;
++	return 0;
++}
++
++static void hello_led_heartbeat_set(struct led_classdev *ldev,
++				    enum led_brightness b)
++{
++	struct hello_dev *hello = container_of(ldev, struct hello_dev,
++					       led_heartbeat);
++	set_brightness(hello, 0, b);
++}
++
++static enum led_brightness hello_led_heartbeat_get(struct led_classdev *ldev)
++{
++	struct hello_dev *hello = container_of(ldev, struct hello_dev,
++					       led_heartbeat);
++	return get_brightness(hello, 0);
++}
++
++static void hello_led_net_set(struct led_classdev *ldev,
++			      enum led_brightness b)
++{
++	struct hello_dev *hello = container_of(ldev, struct hello_dev,
++					       led_net);
++	set_brightness(hello, 1, b);
++}
++
++static enum led_brightness hello_led_net_get(struct led_classdev *ldev)
++{
++	struct hello_dev *hello = container_of(ldev, struct hello_dev,
++					       led_net);
++	return get_brightness(hello, 1);
++}
++
++static void hello_led_disk_set(struct led_classdev *ldev,
++			       enum led_brightness b)
++{
++	struct hello_dev *hello = container_of(ldev, struct hello_dev,
++					       led_disk);
++	set_brightness(hello, 2, b);
++}
++
++static enum led_brightness hello_led_disk_get(struct led_classdev *ldev)
++{
++	struct hello_dev *hello = container_of(ldev, struct hello_dev,
++					       led_disk);
++	return get_brightness(hello, 2);
++}
++
+ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ {
+ 	struct hello_dev *hello;
+@@ -193,6 +259,27 @@ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ 		goto err_cdev;
+ 	}
+ 
++	hello->led_heartbeat.name = "heartbeat";
++	hello->led_heartbeat.brightness = get_brightness(hello, 0);
++	hello->led_heartbeat.max_brightness = 1;
++	hello->led_heartbeat.brightness_set = hello_led_heartbeat_set;
++	hello->led_heartbeat.brightness_get = hello_led_heartbeat_get;
++	led_classdev_register(&pdev->dev, &hello->led_heartbeat);
++
++	hello->led_net.name = "net";
++	hello->led_net.brightness = get_brightness(hello, 2);
++	hello->led_net.max_brightness = 1;
++	hello->led_net.brightness_set = hello_led_net_set;
++	hello->led_net.brightness_get = hello_led_net_get;
++	led_classdev_register(&pdev->dev, &hello->led_net);
++
++	hello->led_disk.name = "disk";
++	hello->led_disk.brightness = get_brightness(hello, 2);
++	hello->led_disk.max_brightness = 1;
++	hello->led_disk.brightness_set = hello_led_disk_set;
++	hello->led_disk.brightness_get = hello_led_disk_get;
++	led_classdev_register(&pdev->dev, &hello->led_disk);
++
+ 	dev_info(&pdev->dev, "HELLO! I am hello device %d!\n", hello->minor);
+ 
+ 	return 0;
+@@ -214,6 +301,9 @@ static void hello_remove(struct pci_dev *pdev)
+ {
+ 	struct hello_dev *hello = pci_get_drvdata(pdev);
+ 
++	led_classdev_unregister(&hello->led_disk);
++	led_classdev_unregister(&hello->led_net);
++	led_classdev_unregister(&hello->led_heartbeat);
+ 	device_destroy(hello_class, MKDEV(MAJOR(hello_devt), hello->minor));
+ 	cdev_del(&hello->cdev);
+ 	pci_iounmap(pdev, hello->mem);
+-- 
+2.11.0
+
diff --git a/schulung_tools/drivers/hellodriver/patches-leds/0006-hello-remove-chardev-use-only-leds-subsystem.patch b/schulung_tools/drivers/hellodriver/patches-leds/0006-hello-remove-chardev-use-only-leds-subsystem.patch
new file mode 100644
index 0000000..3274ccd
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patches-leds/0006-hello-remove-chardev-use-only-leds-subsystem.patch
@@ -0,0 +1,338 @@
+From 5f05842b160249563a7e4965aaa01998e562f487 Mon Sep 17 00:00:00 2001
+From: John Ogness <john.ogness@linutronix.de>
+Date: Fri, 15 Feb 2019 11:33:24 +0100
+Subject: [PATCH 7/7] hello: remove chardev, use only leds subsystem
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+---
+ hello-led.c |  38 -------------
+ hello.c     | 181 +-----------------------------------------------------------
+ hello.h     |   7 ---
+ 3 files changed, 3 insertions(+), 223 deletions(-)
+ delete mode 100644 hello-led.c
+ delete mode 100644 hello.h
+
+diff --git a/hello-led.c b/hello-led.c
+deleted file mode 100644
+index 43230cd..0000000
+--- a/hello-led.c
++++ /dev/null
+@@ -1,38 +0,0 @@
+-#include <stdio.h>
+-#include <string.h>
+-#include <errno.h>
+-#include <fcntl.h>
+-#include <unistd.h>
+-#include <sys/ioctl.h>
+-#include <sys/types.h>
+-#include <sys/stat.h>
+-#include "hello.h"
+-
+-int main(int argc, char *argv[])
+-{
+-	int fd;
+-
+-	if (argc != 3) {
+-		fprintf(stderr, "usage: %s <device> <led>\n", argv[0]);
+-		return 1;
+-	}
+-
+-	fd = open(argv[1], O_RDWR);
+-	if (fd < 0) {
+-		fprintf(stderr, "open() failed: %s\n", strerror(errno));
+-		return 1;
+-	}
+-
+-	if (strcmp(argv[2], "heartbeat") == 0)
+-		ioctl(fd, HELLO_IOCTL_TOGGLE_LED, 0);
+-	else if (strcmp(argv[2], "net") == 0)
+-		ioctl(fd, HELLO_IOCTL_TOGGLE_LED, 1);
+-	else if (strcmp(argv[2], "disk") == 0)
+-		ioctl(fd, HELLO_IOCTL_TOGGLE_LED, 2);
+-	else
+-		fprintf(stderr, "unknown led\n");
+-
+-	close(fd);
+-
+-	return 0;
+-}
+diff --git a/hello.c b/hello.c
+index f9809f3..52df6d7 100644
+--- a/hello.c
++++ b/hello.c
+@@ -1,19 +1,12 @@
+ // SPDX-License-Identifier: GPL-2.0
+ #include <linux/init.h>
+ #include <linux/module.h>
+-#include <linux/fs.h>
+-#include <linux/uaccess.h>
+-#include <linux/slab.h>
+ #include <linux/device.h>
+ #include <linux/pci.h>
+-#include <linux/cdev.h>
+ #include <linux/leds.h>
+-#include "hello.h"
+ 
+ struct hello_dev {
+ 	struct device *dev;
+-	struct cdev cdev;
+-	unsigned int minor;
+ 	void __iomem *mem;
+ 
+ 	struct led_classdev led_heartbeat;
+@@ -21,115 +14,6 @@ struct hello_dev {
+ 	struct led_classdev led_disk;
+ };
+ 
+-#define HELLO_MAX_DEVICES 10
+-
+-static struct class *hello_class;
+-static dev_t hello_devt;
+-
+-static int hello_open(struct inode *node, struct file *f)
+-{
+-	struct cdev *cd = node->i_cdev;
+-	struct hello_dev *hello = container_of(cd, struct hello_dev, cdev);
+-	dev_info(hello->dev, "%s\n", __func__);
+-	f->private_data = hello;
+-	return 0;
+-}
+-
+-static int hello_release(struct inode *node, struct file *f)
+-{
+-	struct hello_dev *hello = f->private_data;
+-	dev_info(hello->dev, "%s\n", __func__);
+-	f->private_data = NULL;
+-	return 0;
+-}
+-
+-static ssize_t hello_read(struct file *f, char __user *u, size_t s, loff_t *l)
+-{
+-	struct hello_dev *hello = f->private_data;
+-	char buf[10];
+-	size_t len;
+-
+-	dev_info(hello->dev, "%s: size=%zu offset=%llu\n", __func__, s, *l);
+-
+-	if (*l >= 40)
+-		return 0;
+-
+-	len = snprintf(buf, sizeof(buf), "hello:%d\n", hello->minor);
+-
+-	if (s < len)
+-		len = s;
+-
+-	if (copy_to_user(u, buf, len) != 0)
+-		return -EFAULT;
+-
+-	*l += len;
+-
+-	return len;
+-}
+-
+-static void toggle_led(struct hello_dev *hello, int offset)
+-{
+-	if (readb(hello->mem + offset))
+-		writeb(0, hello->mem + offset);
+-	else
+-		writeb(0xff, hello->mem + offset);
+-}
+-
+-static ssize_t hello_write(struct file *f, const char __user *u, size_t s,
+-			   loff_t *l)
+-{
+-	struct hello_dev *hello = f->private_data;
+-	size_t sz = s;
+-	char buf[32];
+-
+-	if (sz >= sizeof(buf))
+-		sz = sizeof(buf) - 1;
+-	if (copy_from_user(buf, u, sz) != 0)
+-		return -EFAULT;
+-	buf[sz] = 0;
+-
+-	dev_info(hello->dev, "%s: size=%zu offset=%llu buf=%s\n", __func__,
+-		 s, *l, buf);
+-
+-	if (strstarts(buf, "heartbeat"))
+-		toggle_led(hello, 0);
+-	else if (strstarts(buf, "net"))
+-		toggle_led(hello, 1);
+-	else if (strstarts(buf, "disk"))
+-		toggle_led(hello, 2);
+-
+-	return s;
+-}
+-
+-static long hello_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+-{
+-	struct hello_dev *hello = f->private_data;
+-	u32 val;
+-
+-	dev_info(hello->dev, "%s: cmd=%u arg=%lu\n", __func__, cmd, arg);
+-
+-	switch (cmd) {
+-	case HELLO_IOCTL_TOGGLE_LED:
+-		val = arg;
+-		if (val >= 0 && val <= 2)
+-			toggle_led(hello, val);
+-		break;
+-	default:
+-		return -EINVAL;
+-	}
+-
+-	return 0;
+-}
+-
+-static const struct file_operations hello_fops = {
+-	.owner = THIS_MODULE,
+-	.open = hello_open,
+-	.release = hello_release,
+-	.read = hello_read,
+-	.write = hello_write,
+-	.unlocked_ioctl = hello_ioctl,
+-};
+-
+ static void set_brightness(struct hello_dev *hello, int offset,
+ 			   enum led_brightness b)
+ {
+@@ -194,8 +78,6 @@ static enum led_brightness hello_led_disk_get(struct led_classdev *ldev)
+ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ {
+ 	struct hello_dev *hello;
+-	struct device *dev;
+-	dev_t devt;
+ 	int ret;
+ 
+ 	hello = devm_kzalloc(&pdev->dev, sizeof(*hello), GFP_KERNEL);
+@@ -204,14 +86,6 @@ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ 		return -ENOMEM;
+ 	}
+ 
+-	hello->minor = 1;
+-
+-	if (hello->minor >= HELLO_MAX_DEVICES) {
+-		dev_err(&pdev->dev, "invalid index: %u\n", hello->minor);
+-		ret = -EINVAL;
+-		goto err_out;
+-	}
+-
+ 	hello->dev = &pdev->dev;
+ 	pci_set_drvdata(pdev, hello);
+ 
+@@ -241,24 +115,6 @@ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ 		goto err_regions;
+ 	}
+ 
+-	devt = MKDEV(MAJOR(hello_devt), hello->minor);
+-
+-	cdev_init(&hello->cdev, &hello_fops);
+-	hello->cdev.owner = THIS_MODULE;
+-	ret = cdev_add(&hello->cdev, devt, 1);
+-	if (ret != 0) {
+-		dev_err(&pdev->dev, "cdev_add failed\n");
+-		goto err_iomap;
+-	}
+-
+-	dev = device_create(hello_class, &pdev->dev, devt, hello,
+-			    "hello%d", hello->minor);
+-	if (IS_ERR(dev)) {
+-		dev_err(&pdev->dev, "device_create failed\n");
+-		ret = PTR_ERR(dev);
+-		goto err_cdev;
+-	}
+-
+ 	hello->led_heartbeat.name = "heartbeat";
+ 	hello->led_heartbeat.brightness = get_brightness(hello, 0);
+ 	hello->led_heartbeat.max_brightness = 1;
+@@ -280,14 +136,10 @@ static int hello_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ 	hello->led_disk.brightness_get = hello_led_disk_get;
+ 	led_classdev_register(&pdev->dev, &hello->led_disk);
+ 
+-	dev_info(&pdev->dev, "HELLO! I am hello device %d!\n", hello->minor);
++	dev_info(&pdev->dev, "HELLO! I am hello device!\n");
+ 
+ 	return 0;
+ 
+-err_cdev:
+-	cdev_del(&hello->cdev);
+-err_iomap:
+-	pci_iounmap(pdev, hello->mem);
+ err_regions:
+ 	pci_release_regions(pdev);
+ err_enable:
+@@ -304,14 +156,12 @@ static void hello_remove(struct pci_dev *pdev)
+ 	led_classdev_unregister(&hello->led_disk);
+ 	led_classdev_unregister(&hello->led_net);
+ 	led_classdev_unregister(&hello->led_heartbeat);
+-	device_destroy(hello_class, MKDEV(MAJOR(hello_devt), hello->minor));
+-	cdev_del(&hello->cdev);
+ 	pci_iounmap(pdev, hello->mem);
+ 	pci_release_regions(pdev);
+ 	pci_disable_device(pdev);
+ 	pci_set_drvdata(pdev, NULL);
+ 
+-	dev_info(&pdev->dev, "GOODBYE! I was hello device %d!\n", hello->minor);
++	dev_info(&pdev->dev, "GOODBYE! I was hello device!\n");
+ }
+ 
+ static const struct pci_device_id hello_id_table[] = {
+@@ -329,32 +179,9 @@ static struct pci_driver hello_driver = {
+ 
+ static int __init hello_init(void)
+ {
+-	int ret;
+-
+ 	printk(KERN_INFO "%s\n", __func__);
+ 
+-	ret = alloc_chrdev_region(&hello_devt, 0, HELLO_MAX_DEVICES, "hello");
+-	if (ret < 0)
+-		return ret;
+-
+-	hello_class = class_create(THIS_MODULE, "hello");
+-	if (IS_ERR(hello_class)) {
+-		printk(KERN_ERR "%s: failed to create class\n", __func__);
+-		ret = PTR_ERR(hello_class);
+-		goto err_region;
+-	}
+-
+-	ret = pci_register_driver(&hello_driver);
+-	if (ret != 0)
+-		goto err_class;
+-
+-	return 0;
+-
+-err_class:
+-	class_destroy(hello_class);
+-err_region:
+-	unregister_chrdev_region(hello_devt, HELLO_MAX_DEVICES);
+-	return ret;
++	return pci_register_driver(&hello_driver);
+ }
+ 
+ static void __exit hello_exit(void)
+@@ -362,8 +189,6 @@ static void __exit hello_exit(void)
+ 	printk(KERN_INFO "%s\n", __func__);
+ 
+ 	pci_unregister_driver(&hello_driver);
+-	class_destroy(hello_class);
+-	unregister_chrdev_region(hello_devt, HELLO_MAX_DEVICES);
+ }
+ 
+ module_init(hello_init);
+diff --git a/hello.h b/hello.h
+deleted file mode 100644
+index cb172d9..0000000
+--- a/hello.h
++++ /dev/null
+@@ -1,7 +0,0 @@
+-#ifndef HELLO_H
+-#define HELLO_H
+-
+-#define HELLO_BASE		0x9F
+-#define HELLO_IOCTL_TOGGLE_LED	_IOW(HELLO_BASE, 0x00, unsigned int)
+-
+-#endif /* HELLO_H */
+-- 
+2.11.0
+
diff --git a/schulung_tools/drivers/hellodriver/patches-leds/README b/schulung_tools/drivers/hellodriver/patches-leds/README
new file mode 100644
index 0000000..51bbffa
--- /dev/null
+++ b/schulung_tools/drivers/hellodriver/patches-leds/README
@@ -0,0 +1,6 @@
+This set of patches show how different subsystems can be used
+by the driver to communicate with the hardware and to present
+itself to the user.
+
+For live demonstrations with actual blinking leds, use the
+"leds" program. (See the README there for details.)