path: root/schulung_tools/drivers/hellodriver/patches-leds/0006-hello-remove-chardev-use-only-leds-subsystem.patch

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