Commit ae92bd17 authored by Henrique de Moraes Holschuh's avatar Henrique de Moraes Holschuh Committed by Len Brown
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ACPI: thinkpad-acpi: enable more hotkeys 



Revise ACPI HKEY functionality to better interface with the firmware, and
enable up to 32 regular hotkeys, instead of just 16 of them.  Ouch.

This takes care of most keys one used to have to do CMOS NVRAM polling on,
and should drop the need for tpb, thinkpad-keys, and other such 5Hz NVRAM
polling power vampires on most modern ThinkPads ;-)

And, just to add insult to injury, this was sort of working since forever
through the procfs interface, but nobody noticed or tried an echo
0xffffffff > /proc/acpi/ibm/hotkey and told me it would generate weird
events. ARGH!

Thanks to Richard Hughes for kicking off the work that ended up with this
discovery, and to Matthew Garret for calling my attention to the fact that
newer ThinkPads were indeed generating ACPI GPEs when such hot keys were
pressed.

Signed-off-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Richard Hughes <hughsient@gmail.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent b8b26402

Documentation/thinkpad-acpi.txt

+17 −24
Original line number Diff line number Diff line
@@ -153,29 +153,22 @@ addition, the lid microswitch and some docking station buttons may 
also generate such events.



The bit mask allows some control over which hot keys generate ACPI

events. Not all bits in the mask can be modified. Not all bits that

can be modified do anything. Not all hot keys can be individually

controlled by the mask. Most recent ThinkPad models honor the

following bits (assuming the hot keys feature has been enabled):



	key	bit	behavior when set	behavior when unset



	Fn-F3			always generates ACPI event

	Fn-F4			always generates ACPI event

	Fn-F5	0010	generate ACPI event	enable/disable Bluetooth

	Fn-F7	0040	generate ACPI event	switch LCD and external display

	Fn-F8	0080	generate ACPI event	expand screen or none

	Fn-F9	0100	generate ACPI event	none

	Fn-F12			always generates ACPI event



Some models do not support all of the above. For example, the T30 does

not support Fn-F5 and Fn-F9. Other models do not support the mask at

all. On those models, hot keys cannot be controlled individually.

events. Not all bits in the mask can be modified. Not all bits that can

be modified do anything. Not all hot keys can be individually controlled

by the mask. Some models do not support the mask at all. On those

models, hot keys cannot be controlled individually.



Note that enabling ACPI events for some keys prevents their default

behavior. For example, if events for Fn-F5 are enabled, that key will

no longer enable/disable Bluetooth by itself. This can still be done

from an acpid handler for the ibm/hotkey event.

behavior. For example, if events for Fn-F5 are enabled, that key will no

longer enable/disable Bluetooth by itself. This can still be done from

an acpid handler for the ibm/hotkey event.



On some models, even enabling/disabling the entire hot key feature may

change the way some keys behave (e.g. in a T43, Fn+F4 will generate an

button/sleep ACPI event if hot keys are disabled, and it will ignore its

mask when hot keys are enabled, so the key always does something.  On a

X40, Fn+F4 respects its mask status, but generates the button/sleep ACPI

event if masked off).



Note also that not all Fn key combinations are supported through

ACPI. For example, on the X40, the brightness, volume and "Access IBM"
@@ -189,9 +182,9 @@ The following commands can be written to the /proc/acpi/ibm/hotkey file: 


	echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature

	echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature

	echo 0xffff > /proc/acpi/ibm/hotkey -- enable all possible hot keys

	echo 0x0000 > /proc/acpi/ibm/hotkey -- disable all possible hot keys

	... any other 4-hex-digit mask ...

	echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys

	echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys

	... any other 8-hex-digit mask ...

	echo reset > /proc/acpi/ibm/hotkey -- restore the original mask



sysfs notes:

drivers/misc/thinkpad_acpi.c

+22 −16
Original line number Diff line number Diff line
@@ -727,7 +727,7 @@ static struct ibm_struct thinkpad_acpi_driver_data = { 
 */



static int hotkey_orig_status;

static int hotkey_orig_mask;

static u32 hotkey_orig_mask;



static struct attribute_set *hotkey_dev_attributes;
@@ -736,7 +736,8 @@ static ssize_t hotkey_enable_show(struct device *dev, 
			   struct device_attribute *attr,

			   char *buf)

{

	int res, status, mask;

	int res, status;

	u32 mask;



	res = hotkey_get(&status, &mask);

	if (res)
@@ -750,7 +751,8 @@ static ssize_t hotkey_enable_store(struct device *dev, 
			    const char *buf, size_t count)

{

	unsigned long t;

	int res, status, mask;

	int res, status;

	u32 mask;



	if (parse_strtoul(buf, 1, &t))

		return -EINVAL;
@@ -771,13 +773,14 @@ static ssize_t hotkey_mask_show(struct device *dev, 
			   struct device_attribute *attr,

			   char *buf)

{

	int res, status, mask;

	int res, status;

	u32 mask;



	res = hotkey_get(&status, &mask);

	if (res)

		return res;



	return snprintf(buf, PAGE_SIZE, "0x%04x\n", mask);

	return snprintf(buf, PAGE_SIZE, "0x%08x\n", mask);

}



static ssize_t hotkey_mask_store(struct device *dev,
@@ -785,9 +788,10 @@ static ssize_t hotkey_mask_store(struct device *dev, 
			    const char *buf, size_t count)

{

	unsigned long t;

	int res, status, mask;

	int res, status;

	u32 mask;



	if (parse_strtoul(buf, 0xffff, &t))

	if (parse_strtoul(buf, 0xffffffffUL, &t))

		return -EINVAL;



	res = hotkey_get(&status, &mask);
@@ -817,7 +821,7 @@ static ssize_t hotkey_bios_mask_show(struct device *dev, 
			   struct device_attribute *attr,

			   char *buf)

{

	return snprintf(buf, PAGE_SIZE, "0x%04x\n", hotkey_orig_mask);

	return snprintf(buf, PAGE_SIZE, "0x%08x\n", hotkey_orig_mask);

}



static struct device_attribute dev_attr_hotkey_bios_mask =
@@ -902,10 +906,10 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event) 
{

	int hkey;



	if (acpi_evalf(hkey_handle, &hkey, "MHKP", "d"))

	if (event == 0x80 && acpi_evalf(hkey_handle, &hkey, "MHKP", "d")) {

		acpi_bus_generate_event(ibm->acpi->device, event, hkey);

	else {

		printk(IBM_ERR "unknown hotkey event %d\n", event);

	} else {

		printk(IBM_ERR "unknown hotkey notification event %d\n", event);

		acpi_bus_generate_event(ibm->acpi->device, event, 0);

	}

}
@@ -913,7 +917,7 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event) 
/*

 * Call with hotkey_mutex held

 */

static int hotkey_get(int *status, int *mask)

static int hotkey_get(int *status, u32 *mask)

{

	if (!acpi_evalf(hkey_handle, status, "DHKC", "d"))

		return -EIO;
@@ -928,7 +932,7 @@ static int hotkey_get(int *status, int *mask) 
/*

 * Call with hotkey_mutex held

 */

static int hotkey_set(int status, int mask)

static int hotkey_set(int status, u32 mask)

{

	int i;
@@ -949,7 +953,8 @@ static int hotkey_set(int status, int mask) 
/* procfs -------------------------------------------------------------- */

static int hotkey_read(char *p)

{

	int res, status, mask;

	int res, status;

	u32 mask;

	int len = 0;



	if (!tp_features.hotkey) {
@@ -967,7 +972,7 @@ static int hotkey_read(char *p) 


	len += sprintf(p + len, "status:\t\t%s\n", enabled(status, 0));

	if (tp_features.hotkey_mask) {

		len += sprintf(p + len, "mask:\t\t0x%04x\n", mask);

		len += sprintf(p + len, "mask:\t\t0x%08x\n", mask);

		len += sprintf(p + len,

			       "commands:\tenable, disable, reset, <mask>\n");

	} else {
@@ -980,7 +985,8 @@ static int hotkey_read(char *p) 


static int hotkey_write(char *buf)

{

	int res, status, mask;

	int res, status;

	u32 mask;

	char *cmd;

	int do_cmd = 0;

drivers/misc/thinkpad_acpi.h

+3 −3
Original line number Diff line number Diff line
@@ -415,14 +415,14 @@ static int fan_write_cmd_watchdog(const char *cmd, int *rc); 
 */



static int hotkey_orig_status;

static int hotkey_orig_mask;

static u32 hotkey_orig_mask;



static struct mutex hotkey_mutex;



static int hotkey_init(struct ibm_init_struct *iibm);

static void hotkey_exit(void);

static int hotkey_get(int *status, int *mask);

static int hotkey_set(int status, int mask);

static int hotkey_get(int *status, u32 *mask);

static int hotkey_set(int status, u32 mask);

static void hotkey_notify(struct ibm_struct *ibm, u32 event);

static int hotkey_read(char *p);

static int hotkey_write(char *buf);

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