Re: [PATCH] Integrate asus_acpi LED's with new LED subsystem

From: Thomas Tuttle
Date: Thu Jul 06 2006 - 21:18:56 EST


Here is a patch to the asus_acpi driver that links the Asus laptop LED's
into the new LED subsystem. It creates LED class devices named
asus:mail, asus:wireless, and asus:touchpad, depending on if the laptop
supports the mled, wled, and tled LED's.

Since it's so new, I added a config option to turn it on and off. It's
worked for me, though I have an Asus M2N, which only has the mail and
wireless LED's.

Signed-off-by: Thomas Tuttle <thinkinginbinary@xxxxxxxxx>


I believe I've fixed everything you asked about, plus a few things
Richard Purdie (the LED subsystem guy) suggested.

On July 06 at 18:49 EDT, Andrew Morton hastily scribbled:
> Thomas Tuttle <thinkinginbinary@xxxxxxxxx> wrote:
> > +#ifdef CONFIG_ACPI_ASUS_NEW_LED
> > +#include <linux/leds.h>
> > +#endif
> The ifdef shouldn't be required. If it is, ldes.h needs fixing.
Fixed.

> This mingles declarations with definitions. It's more conventional to keep
> them together.
Fixed. I moved all the declarations together, and initialized the
led_cdev structs if and when they are going to be registered. (Just as
with the zero initializers, this should stop them from wasting space in
.vmlinux.)

> Please don' t initialise static storage to zero (the "= 0"). The C runtime
> environment does that already, and the above construct will place the
> values into .data and hence into .vmlinux.
Fixed.

> > +/* LED update work structs. */
> These all should be declared static.
Fixed.

> > +/* LED work functions. */
> > +static void led_update_mled(void *private) {
> The opening brace goes in column 1.
Fixed.

> It's usual to put a blank line at the end of the declaration of the
> automatic valriables.
Fixed.

> Add:
>
> #else
> static inline int led_initialize(struct device *parent)
> {
> }
>
> static inline void led_terminate(void)
> {
> }
> #endif
Fixed.

> > +#ifdef CONFIG_ACPI_ASUS_NEW_LED
> > + result = led_initialize(acpi_get_physical_device(device->handle));
> > +#endif
> > +
> >
> > +#ifdef CONFIG_ACPI_ASUS_NEW_LED
> > + led_terminate();
> > +#endif
> > +
> And remove these ifdefs.
Fixed.

I believe it's a little less ugly now. The declarations are better
organized, error recovery from the initialization is better (sorry to
use goto, but if I didn't, I'd have to duplicate the abort code for each
possible point of failure).

This revision is essentially the same, functionally, and it appears to
work in quick testing. I think it would be nice if someone else with an
Asus laptop could give this a test before it goes into mainline. The
code that updates the LED's is basically copied from the /proc
interface, but testing is good.

-- Thomas Tuttle
diff -udrN linux-2.6.17-git25/drivers/acpi/asus_acpi.c linux-2.6.17-git25-mine/drivers/acpi/asus_acpi.c
--- linux-2.6.17-git25/drivers/acpi/asus_acpi.c 2006-07-05 22:11:37.000000000 -0400
+++ linux-2.6.17-git25-mine/drivers/acpi/asus_acpi.c 2006-07-06 21:06:58.000000000 -0400
@@ -27,6 +27,7 @@
* Johann Wiesner - Small compile fixes
* John Belmonte - ACPI code for Toshiba laptop was a good starting point.
* Éric Burghard - LED display support for W1N
+ * Thomas Tuttle - LED subsystem integration
*
*/

@@ -35,6 +36,7 @@
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
+#include <linux/leds.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>
#include <asm/uaccess.h>
@@ -916,6 +918,158 @@
return 0;
}

+#ifdef CONFIG_ACPI_ASUS_NEW_LED
+
+static struct led_classdev led_cdev_mled, led_cdev_wled, led_cdev_tled;
+
+/* Desired values of LED's. */
+static int led_mled_value;
+static int led_wled_value;
+static int led_tled_value;
+
+/* These functions are called by the LED subsystem to update the desired
+ * state of the LED's. */
+static void led_set_mled(struct led_classdev *led_cdev,
+ enum led_brightness value);
+static void led_set_wled(struct led_classdev *led_cdev,
+ enum led_brightness value);
+static void led_set_tled(struct led_classdev *led_cdev,
+ enum led_brightness value);
+
+/* The LED update functions can be called in interrupt context, so we
+ * use a work queue to pass the updates to ACPI at a safer time. */
+static void led_update_mled(void *private);
+static void led_update_wled(void *private);
+static void led_update_tled(void *private);
+
+/* LED workqueue. */
+static struct workqueue_struct *led_workqueue;
+
+/* LED update work structs. */
+static DECLARE_WORK(led_mled_work, led_update_mled, NULL);
+static DECLARE_WORK(led_wled_work, led_update_wled, NULL);
+static DECLARE_WORK(led_tled_work, led_update_tled, NULL);
+
+/* LED subsystem callbacks. */
+static void led_set_mled(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ led_mled_value = value;
+ queue_work(led_workqueue, &led_mled_work);
+}
+
+static void led_set_wled(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ led_wled_value = value;
+ queue_work(led_workqueue, &led_wled_work);
+}
+
+static void led_set_tled(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ led_tled_value = value;
+ queue_work(led_workqueue, &led_tled_work);
+}
+
+/* LED work functions. */
+static void led_update_mled(void *private)
+{
+ char *ledname = hotk->methods->mt_mled;
+ int led_out = led_mled_value ? 1 : 0;
+
+ hotk->status = (led_out) ? (hotk->status | MLED_ON) : (hotk->status & ~MLED_ON);
+ led_out = 1 - led_out;
+ if (!write_acpi_int(hotk->handle, ledname, led_out, NULL))
+ printk(KERN_WARNING "Asus ACPI: Writing MLED failed.\n");
+}
+
+static void led_update_wled(void *private)
+{
+ char *ledname = hotk->methods->mt_wled;
+ int led_out = led_wled_value ? 1 : 0;
+
+ hotk->status = (led_out) ? (hotk->status | WLED_ON) : (hotk->status & ~WLED_ON);
+ if (!write_acpi_int(hotk->handle, ledname, led_out, NULL))
+ printk(KERN_WARNING "Asus ACPI: Writing WLED failed.\n");
+}
+
+static void led_update_tled(void *private)
+{
+ char *ledname = hotk->methods->mt_tled;
+ int led_out = led_tled_value ? 1 : 0;
+
+ hotk->status = (led_out) ? (hotk->status | TLED_ON) : (hotk->status & ~TLED_ON);
+ if (!write_acpi_int(hotk->handle, ledname, led_out, NULL))
+ printk(KERN_WARNING "Asus ACPI: Writing TLED failed.\n");
+}
+
+/* Registers LED class devices and sets up workqueue. */
+static int led_initialize(struct device *parent)
+{
+ int result;
+
+ if (hotk->methods->mt_mled) {
+ led_cdev_mled.name = "asus:mail";
+ led_cdev_mled.brightness_set = led_set_mled;
+ result = led_classdev_register(parent, &led_cdev_mled);
+ if (result) goto mled_abort;
+ }
+
+ if (hotk->methods->mt_wled) {
+ led_cdev_wled.name = "asus:wireless";
+ led_cdev_wled.brightness_set = led_set_wled;
+ result = led_classdev_register(parent, &led_cdev_wled);
+ if (result) goto wled_abort;
+ }
+
+ if (hotk->methods->mt_tled) {
+ led_cdev_tled.name = "asus:touchpad";
+ led_cdev_tled.brightness_set = led_set_tled;
+ result = led_classdev_register(parent, &led_cdev_tled);
+ if (result) goto tled_abort;
+ }
+
+ led_workqueue = create_singlethread_workqueue("led_workqueue");
+
+ return 0;
+
+tled_abort:
+ if (hotk->methods->mt_wled) led_classdev_unregister(&led_cdev_wled);
+wled_abort:
+ if (hotk->methods->mt_mled) led_classdev_unregister(&led_cdev_mled);
+mled_abort:
+ return result;
+
+}
+
+/* Destroys the workqueue and unregisters the LED class devices. */
+static void led_terminate(void)
+{
+ destroy_workqueue(led_workqueue);
+
+ if (hotk->methods->mt_tled)
+ led_classdev_unregister(&led_cdev_tled);
+
+ if (hotk->methods->mt_wled)
+ led_classdev_unregister(&led_cdev_wled);
+
+ if (hotk->methods->mt_mled)
+ led_classdev_unregister(&led_cdev_mled);
+}
+
+#else
+
+static inline int led_initialize(struct device *parent)
+{
+}
+
+static inline void led_terminate(void)
+{
+}
+
+#endif
+
static int asus_hotk_add_fs(struct acpi_device *device)
{
struct proc_dir_entry *proc;
@@ -1299,6 +1453,8 @@
/* LED display is off by default */
hotk->ledd_status = 0xFFF;

+ result = led_initialize(acpi_get_physical_device(device->handle));
+
end:
if (result) {
kfree(hotk);
@@ -1314,6 +1470,8 @@
if (!device || !acpi_driver_data(device))
return -EINVAL;

+ led_terminate();
+
status = acpi_remove_notify_handler(hotk->handle, ACPI_SYSTEM_NOTIFY,
asus_hotk_notify);
if (ACPI_FAILURE(status))
diff -udrN linux-2.6.17-git25/drivers/acpi/Kconfig linux-2.6.17-git25-mine/drivers/acpi/Kconfig
--- linux-2.6.17-git25/drivers/acpi/Kconfig 2006-07-05 22:44:33.000000000 -0400
+++ linux-2.6.17-git25-mine/drivers/acpi/Kconfig 2006-07-05 22:44:43.000000000 -0400
@@ -199,6 +199,15 @@
something works not quite as expected, please use the mailing list
available on the above page (acpi4asus-user@xxxxxxxxxxxxxxxxxxxxx)

+config ACPI_ASUS_NEW_LED
+ bool "ASUS/Medion LED subsystem integration"
+ depends on ACPI_ASUS
+ depends on LEDS_CLASS
+ help
+ This adds support for the new LED subsystem to the asus_acpi
+ driver. The LED's will show up as asus:mail, asus:wireless,
+ and asus:touchpad, as applicable to your laptop.
+
config ACPI_IBM
tristate "IBM ThinkPad Laptop Extras"
depends on X86

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