path: root/schulung_tools/drivers/patch-kernel-hello.diff

diff -urNp a/drivers/char/hello.c b/drivers/char/hello.c
--- a/drivers/char/hello.c	1970-01-01 01:00:00.000000000 +0100
+++ b/drivers/char/hello.c	2016-06-08 20:46:01.991211855 +0200
@@ -0,0 +1,255 @@
+#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 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;
+	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_out1;
+	}
+#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_out1;
+	}
+
+	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_out1;
+	}
+
+	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_out2;
+	}
+
+	dev_info(&pdev->dev, "HELLO! I am hello device %d!\n", hello->minor);
+
+	return 0;
+
+err_out2:
+	cdev_del(&hello->cdev);
+err_out1:
+	platform_set_drvdata(pdev, NULL);
+	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",
+		.owner = THIS_MODULE,
+		.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_out1;
+	}
+
+	hello_class->dev_groups = hello_device_groups;
+
+	ret = platform_driver_register(&hello_driver);
+	if (ret != 0)
+		goto err_out2;
+
+#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_out2:
+	class_destroy(hello_class);
+err_out1:
+	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("20160607");
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