schulung_tools: hellodriver: add patches for use with leds

These patches are based heavily on the work by Manu to make the
driver lessons more interesting. Rather than create a new driver,
I took his work and created a series of patches that do
interesting modifications to the hello driver.

These patches can be used together with the "leds" program to
do live blinking demonstrations.

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

1 files changed, 338 insertions, 0 deletions

diff --git a/schulung_tools/drivers/modules/hellodriver/patches-leds/0006-hello-remove-chardev-use-only-leds-subsystem.patch b/schulung_tools/drivers/modules/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/modules/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
+