xref: /linux/Documentation/ABI/testing/sysfs-driver-intc_sar (revision 762f99f4f3cb41a775b5157dd761217beba65873)
1*dcfbd31eSShravan SWhat:		/sys/bus/platform/devices/INTC1092:00/intc_reg
2*dcfbd31eSShravan SDate:		August 2021
3*dcfbd31eSShravan SKernelVersion:	5.15
4*dcfbd31eSShravan SContact:	Shravan S <s.shravan@intel.com>,
5*dcfbd31eSShravan S		An Sudhakar <sudhakar.an@intel.com>
6*dcfbd31eSShravan SDescription:
7*dcfbd31eSShravan S		Specific Absorption Rate (SAR) regulatory mode is typically
8*dcfbd31eSShravan S		derived based on information like mcc (Mobile Country Code) and
9*dcfbd31eSShravan S		mnc (Mobile Network Code) that is available for the currently
10*dcfbd31eSShravan S		attached LTE network. A userspace application is required to set
11*dcfbd31eSShravan S		the current SAR regulatory mode on the Dynamic SAR driver using
12*dcfbd31eSShravan S		this sysfs node. Such an application can also read back using
13*dcfbd31eSShravan S		this sysfs node, the currently configured regulatory mode value
14*dcfbd31eSShravan S		from the Dynamic SAR driver.
15*dcfbd31eSShravan S
16*dcfbd31eSShravan S		Acceptable regulatory modes are:
17*dcfbd31eSShravan S			==	====
18*dcfbd31eSShravan S			0	FCC
19*dcfbd31eSShravan S			1	CE
20*dcfbd31eSShravan S			2	ISED
21*dcfbd31eSShravan S			==	====
22*dcfbd31eSShravan S
23*dcfbd31eSShravan S		- The regulatory mode value has one of the above values.
24*dcfbd31eSShravan S		- The default regulatory mode used in the driver is 0.
25*dcfbd31eSShravan S
26*dcfbd31eSShravan SWhat:		/sys/bus/platform/devices/INTC1092:00/intc_data
27*dcfbd31eSShravan SDate:		August 2021
28*dcfbd31eSShravan SKernelVersion:	5.15
29*dcfbd31eSShravan SContact:	Shravan S <s.shravan@intel.com>,
30*dcfbd31eSShravan S		An Sudhakar <sudhakar.an@intel.com>
31*dcfbd31eSShravan SDescription:
32*dcfbd31eSShravan S		This sysfs entry is used to retrieve Dynamic SAR information
33*dcfbd31eSShravan S		emitted/maintained by a BIOS that supports Dynamic SAR.
34*dcfbd31eSShravan S
35*dcfbd31eSShravan S		The retrieved information is in the order given below:
36*dcfbd31eSShravan S		- device_mode
37*dcfbd31eSShravan S		- bandtable_index
38*dcfbd31eSShravan S		- antennatable_index
39*dcfbd31eSShravan S		- sartable_index
40*dcfbd31eSShravan S
41*dcfbd31eSShravan S		The above information is sent as integer values separated
42*dcfbd31eSShravan S		by a single space. This information can then be pushed to a
43*dcfbd31eSShravan S		WWAN modem that uses this to control the transmit signal
44*dcfbd31eSShravan S		level using the Band/Antenna/SAR table index information.
45*dcfbd31eSShravan S		These parameters are derived/decided by aggregating
46*dcfbd31eSShravan S		device-mode like laptop/tablet/clamshell etc. and the
47*dcfbd31eSShravan S		proximity-sensor data available to the embedded controller on
48*dcfbd31eSShravan S		given host. The regulatory mode configured on Dynamic SAR
49*dcfbd31eSShravan S		driver also influences these values.
50*dcfbd31eSShravan S
51*dcfbd31eSShravan S		The userspace applications can poll for changes to this file
52*dcfbd31eSShravan S		using POLLPRI event on file-descriptor (fd) obtained by opening
53*dcfbd31eSShravan S		this sysfs entry. Application can then read this information from
54*dcfbd31eSShravan S		the sysfs node and consume the given information.
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