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* [lm-sensors] [PATCH] applesmc: add sysfs file to report OSK
@ 2012-12-10 14:51 ` Gabriel L. Somlo
  0 siblings, 0 replies; 24+ messages in thread
From: Gabriel L. Somlo @ 2012-12-10 14:51 UTC (permalink / raw)
  To: rydberg, khali, linux, lm-sensors, linux-kernel; +Cc: agraf, rene

The AppleSMC contains two char[32] keys, OSK0 and OSK1, which are not
reported in the key count and index by default. These keys are used by
the OS X boot sequence, and normally don't matter when running Linux.

This patch creates a sysfs entry which reports the value of these keys
as an ASCII string, to help emulators (such as QEMU) load OS X when
running on genuine Apple hardware.

Signed-off-by: Gabriel L. Somlo <somlo@cmu.edu>
---

For extra context: To boot OS X as a guest, QEMU must (among others)
emulate the AppleSMC. To boot successfully, OS X insists on querying
the (emulated) SMC for the value of OSK0 and OSK1. Currently, these
values must be supplied on the QEMU command line as

  -device applesmc,osk="...concatenated values of OSK0 and OSK1..."

With the availability of /sys/devices/platform/applesmc.768/osk, the
emulated QEMU AppleSMC could acquire this string directly from the
(Apple-manufactured) host machine.

Thanks,
  Gabriel

 drivers/hwmon/applesmc.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
index b41baff..0c7cc71 100644
--- a/drivers/hwmon/applesmc.c
+++ b/drivers/hwmon/applesmc.c
@@ -1013,6 +1013,23 @@ static ssize_t applesmc_key_at_index_store(struct device *dev,
 	return count;
 }
 
+static ssize_t applesmc_osk_show(struct device *dev,
+				struct device_attribute *attr, char *sysfsbuf)
+{
+	int fail;
+
+	mutex_lock(&smcreg.mutex);
+	fail = read_smc(APPLESMC_READ_CMD, "OSK0", sysfsbuf, 32) ||
+	       read_smc(APPLESMC_READ_CMD, "OSK1", sysfsbuf + 32, 32);
+	mutex_unlock(&smcreg.mutex);
+	if (fail)
+		return -1;
+
+	sysfsbuf[64] = '\n';
+	sysfsbuf[65] = '\0';
+	return 65;
+}
+
 static struct led_classdev applesmc_backlight = {
 	.name			= "smc::kbd_backlight",
 	.default_trigger	= "nand-disk",
@@ -1027,6 +1044,7 @@ static struct applesmc_node_group info_group[] = {
 	{ "key_at_index_type", applesmc_key_at_index_type_show },
 	{ "key_at_index_data_length", applesmc_key_at_index_data_length_show },
 	{ "key_at_index_data", applesmc_key_at_index_read_show },
+	{ "osk", applesmc_osk_show },
 	{ }
 };
 
-- 
1.7.7.6


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^ permalink raw reply related	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2012-12-13 19:09 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-12-10 14:51 [lm-sensors] [PATCH] applesmc: add sysfs file to report OSK Gabriel L. Somlo
2012-12-10 14:51 ` Gabriel L. Somlo
2012-12-10 16:44 ` [lm-sensors] " Alexander Graf
2012-12-10 16:44   ` Alexander Graf
2012-12-10 19:09 ` [lm-sensors] " Guenter Roeck
2012-12-10 19:09   ` Guenter Roeck
2012-12-10 19:54   ` [lm-sensors] " Henrik Rydberg
2012-12-10 19:54     ` Henrik Rydberg
2012-12-10 20:19     ` [lm-sensors] " Alexander Graf
2012-12-10 20:19       ` Alexander Graf
2012-12-10 20:43       ` [lm-sensors] " Rene Rebe
2012-12-10 20:43         ` Rene Rebe
2012-12-10 21:24         ` [lm-sensors] " Alexander Graf
2012-12-10 21:24           ` Alexander Graf
2012-12-10 21:30           ` [lm-sensors] " Rene Rebe
2012-12-10 21:30             ` Rene Rebe
2012-12-10 22:23     ` [lm-sensors] [PATCH v2] " Gabriel L. Somlo
2012-12-10 22:23       ` Gabriel L. Somlo
2012-12-12 23:01       ` [lm-sensors] " Gabriel L. Somlo
2012-12-12 23:01         ` Gabriel L. Somlo
2012-12-13  7:20         ` [lm-sensors] " Henrik Rydberg
2012-12-13  7:20           ` Henrik Rydberg
2012-12-13 19:07           ` [lm-sensors] " Gabriel L. Somlo
2012-12-13 19:07             ` Gabriel L. Somlo

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