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ACPI: thinkpad-acpi: enable more hotkeys
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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: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Richard Hughes <hughsient@gmail.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Len Brown <len.brown@intel.com>
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Henrique de Moraes Holschuh authored and Len Brown committed Jul 22, 2007
1 parent b8b2640 commit ae92bd1
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Showing 3 changed files with 42 additions and 43 deletions.
41 changes: 17 additions & 24 deletions Documentation/thinkpad-acpi.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -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"
Expand All @@ -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:
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38 changes: 22 additions & 16 deletions drivers/misc/thinkpad_acpi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;

Expand All @@ -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)
Expand All @@ -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;
Expand All @@ -771,23 +773,25 @@ 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,
struct device_attribute *attr,
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);
Expand Down Expand Up @@ -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 =
Expand Down Expand Up @@ -902,18 +906,18 @@ 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);
}
}

/*
* 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;
Expand All @@ -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;

Expand All @@ -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) {
Expand All @@ -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 {
Expand All @@ -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;

Expand Down
6 changes: 3 additions & 3 deletions drivers/misc/thinkpad_acpi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down

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