Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b616004c authored by Henrique de Moraes Holschuh's avatar Henrique de Moraes Holschuh Committed by Len Brown
Browse files

ACPI: thinkpad-acpi: add sysfs support to the cmos command subdriver 



Add sysfs attributes to send ThinkPad CMOS commands.

Signed-off-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent eaa7571b

Documentation/thinkpad-acpi.txt

+11 −12
Original line number Diff line number Diff line
@@ -378,23 +378,19 @@ supported. Use "eject2" instead of "eject" for the second bay. 
Note: the UltraBay eject support on the 600e/x, A22p and A3x is

EXPERIMENTAL and may not work as expected. USE WITH CAUTION!



CMOS control -- /proc/acpi/ibm/cmos

-----------------------------------

CMOS control

------------



procfs: /proc/acpi/ibm/cmos

sysfs device attribute: cmos_command



This feature is used internally by the ACPI firmware to control the

ThinkLight on most newer ThinkPad models. It may also control LCD

brightness, sounds volume and more, but only on some models.



The commands are non-negative integer numbers:



	echo 0 >/proc/acpi/ibm/cmos

	echo 1 >/proc/acpi/ibm/cmos

	echo 2 >/proc/acpi/ibm/cmos

	...



The range of valid numbers is 0 to 21, but not all have an effect and

the behavior varies from model to model. Here is the behavior on the

X40 (tpb is the ThinkPad Buttons utility):

The range of valid cmos command numbers is 0 to 21, but not all have an

effect and the behavior varies from model to model.  Here is the behavior

on the X40 (tpb is the ThinkPad Buttons utility):



	0 - no effect but tpb reports "Volume down"

	1 - no effect but tpb reports "Volume up"
@@ -407,6 +403,9 @@ X40 (tpb is the ThinkPad Buttons utility): 
	13 - ThinkLight off

	14 - no effect but tpb reports ThinkLight status change



The cmos command interface is prone to firmware split-brain problems, as

in newer ThinkPads it is just a compatibility layer.



LED control -- /proc/acpi/ibm/led

---------------------------------

drivers/misc/thinkpad_acpi.c

+33 −0
Original line number Diff line number Diff line
@@ -1743,8 +1743,30 @@ static struct ibm_struct bay_driver_data = { 
 * CMOS subdriver

 */



/* sysfs cmos_command -------------------------------------------------- */

static ssize_t cmos_command_store(struct device *dev,

			    struct device_attribute *attr,

			    const char *buf, size_t count)

{

	unsigned long cmos_cmd;

	int res;



	if (parse_strtoul(buf, 21, &cmos_cmd))

		return -EINVAL;



	res = issue_thinkpad_cmos_command(cmos_cmd);

	return (res)? res : count;

}



static struct device_attribute dev_attr_cmos_command =

	__ATTR(cmos_command, S_IWUSR, NULL, cmos_command_store);



/* --------------------------------------------------------------------- */



static int __init cmos_init(struct ibm_init_struct *iibm)

{

	int res;



	vdbg_printk(TPACPI_DBG_INIT,

		"initializing cmos commands subdriver\n");
@@ -1752,9 +1774,19 @@ static int __init cmos_init(struct ibm_init_struct *iibm) 


	vdbg_printk(TPACPI_DBG_INIT, "cmos commands are %s\n",

		str_supported(cmos_handle != NULL));



	res = device_create_file(&tpacpi_pdev->dev, &dev_attr_cmos_command);

	if (res)

		return res;



	return (cmos_handle)? 0 : 1;

}



static void cmos_exit(void)

{

	device_remove_file(&tpacpi_pdev->dev, &dev_attr_cmos_command);

}



static int cmos_read(char *p)

{

	int len = 0;
@@ -1795,6 +1827,7 @@ static struct ibm_struct cmos_driver_data = { 
	.name = "cmos",

	.read = cmos_read,

	.write = cmos_write,

	.exit = cmos_exit,

};



/*************************************************************************