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, 56 insertions, 0 deletions

diff --git a/schulung_tools/drivers/modules/hellodriver/patches-leds/0003-hello-add-led-toggling-via-chardev-read-write.patch b/schulung_tools/drivers/modules/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/modules/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
+