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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
|
