forked from ~ljy/RK356X_SDK_RELEASE
kernel/Documentation/ABI/testing/sysfs-bus-iio
.. .. @@ -15,6 +15,7 @@ 15 15 based on hardware generated events (e.g. data ready) or 16 16 provided by a separate driver for other hardware (e.g. 17 17 periodic timer, GPIO or high resolution timer). 18 18 19 Contains trigger type specific elements. These do not 19 20 generalize well and hence are not documented in this file. 20 21 X is the IIO index of the trigger. .. .. @@ -40,6 +41,7 @@ 40 41 buffered samples and events for device X. 41 42 42 43 What: /sys/bus/iio/devices/iio:deviceX/sampling_frequency 44 43 45 What: /sys/bus/iio/devices/iio:deviceX/buffer/sampling_frequency 44 46 What: /sys/bus/iio/devices/triggerX/sampling_frequency 45 47 KernelVersion: 2.6.35 .. .. @@ -49,20 +51,25 @@ 49 51 resulting sampling frequency. In many devices this 50 52 parameter has an effect on input filters etc. rather than 51 53 simply controlling when the input is sampled. As this 52 54 53 55 direct access interfaces, it may be found in any of the 54 56 55 57 then it is to be found in the base device directory. 56 58 57 59 What: /sys/bus/iio/devices/iio:deviceX/sampling_frequency_available 60 58 61 What: /sys/bus/iio/devices/iio:deviceX/in_proximity_sampling_frequency_available 59 62 What: /sys/.../iio:deviceX/buffer/sampling_frequency_available 60 63 What: /sys/bus/iio/devices/triggerX/sampling_frequency_available 61 64 KernelVersion: 2.6.35 62 65 Contact: linux-iio@vger.kernel.org 63 66 Description: 64 65 67 68 69 70 71 72 66 73 67 74 What: /sys/bus/iio/devices/iio:deviceX/oversampling_ratio 68 75 KernelVersion: 2.6.38 .. .. @@ -135,7 +142,7 @@ 135 142 Raw capacitance measurement from channel Y. Units after 136 143 application of scale and offset are nanofarads. 137 144 138 145 139 146 KernelVersion: 3.2 140 147 Contact: linux-iio@vger.kernel.org 141 148 Description: .. .. @@ -371,6 +378,9 @@ 371 378 What: /sys/bus/iio/devices/iio:deviceX/in_illuminance_scale 372 379 What: /sys/bus/iio/devices/iio:deviceX/in_countY_scale 373 380 What: /sys/bus/iio/devices/iio:deviceX/in_angl_scale 381 382 383 374 384 KernelVersion: 2.6.35 375 385 Contact: linux-iio@vger.kernel.org 376 386 Description: .. .. @@ -398,21 +408,21 @@ 398 408 Hardware applied calibration offset (assumed to fix production 399 409 inaccuracies). 400 410 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 416 426 What: /sys/bus/iio/devices/iio:deviceX/in_pressureY_calibscale 417 427 What: /sys/bus/iio/devices/iio:deviceX/in_pressure_calibscale 418 428 What: /sys/bus/iio/devices/iio:deviceX/in_illuminance_calibscale .. .. @@ -480,7 +490,8 @@ 480 490 If a discrete set of scale values is available, they 481 491 are listed in this attribute. 482 492 483 493 494 484 495 What: /sys/bus/iio/devices/iio:deviceX/in_intensity_red_hardwaregain 485 496 What: /sys/bus/iio/devices/iio:deviceX/in_intensity_green_hardwaregain 486 497 What: /sys/bus/iio/devices/iio:deviceX/in_intensity_blue_hardwaregain .. .. @@ -490,6 +501,13 @@ 490 501 Description: 491 502 Hardware applied gain factor. If shared across all channels, 492 503 <type>_hardwaregain is used. 504 505 506 507 508 509 510 493 511 494 512 What: /sys/.../in_accel_filter_low_pass_3db_frequency 495 513 What: /sys/.../in_magn_filter_low_pass_3db_frequency .. .. @@ -649,6 +667,7 @@ 649 667 <type>[Y][_name]_<raw|input>_thresh_falling_value may take 650 668 different values, but the device can only enable both thresholds 651 669 or neither. 670 652 671 Note the driver will assume the last p events requested are 653 672 to be enabled where p is how many it supports (which may vary 654 673 depending on the exact set requested. So if you want to be .. .. @@ -703,6 +722,7 @@ 703 722 <type>[Y][_name]_<raw|input>_roc_falling_value may take 704 723 different values, but the device can only enable both rate of 705 724 change thresholds or neither. 725 706 726 Note the driver will assume the last p events requested are 707 727 to be enabled where p is however many it supports (which may 708 728 vary depending on the exact set requested. So if you want to be .. .. @@ -747,18 +767,22 @@ 747 767 What: /sys/.../events/in_tempY_raw_thresh_rising_value 748 768 What: /sys/.../events/in_tempY_raw_thresh_falling_value 749 769 What: /sys/.../events/in_illuminance0_thresh_falling_value 750 751 752 770 771 772 773 774 753 775 KernelVersion: 2.6.37 754 776 Contact: linux-iio@vger.kernel.org 755 777 Description: 756 778 Specifies the value of threshold that the device is comparing 757 779 against for the events enabled by 758 780 <type>Y[_name]_thresh[_rising|falling]_en. 781 759 782 If separate attributes exist for the two directions, but 760 783 direction is not specified for this attribute, then a single 761 784 threshold value applies to both directions. 785 762 786 The raw or input element of the name indicates whether the 763 787 value is in raw device units or in processed units (as _raw 764 788 and _input do on sysfs direct channel read attributes). .. .. @@ -827,11 +851,11 @@ 827 851 What: /sys/.../events/in_tempY_thresh_falling_hysteresis 828 852 What: /sys/.../events/in_tempY_thresh_either_hysteresis 829 853 What: /sys/.../events/in_illuminance0_thresh_falling_hysteresis 830 831 832 833 834 854 855 856 857 858 835 859 KernelVersion: 3.13 836 860 Contact: linux-iio@vger.kernel.org 837 861 Description: .. .. @@ -841,6 +865,7 @@ 841 865 If separate attributes exist for the two directions, but 842 866 direction is not specified for this attribute, then a single 843 867 hysteresis value applies to both directions. 868 844 869 For falling events the hysteresis is added to the _value attribute for 845 870 this event to get the upper threshold for when the event goes back to 846 871 normal, for rising events the hysteresis is subtracted from the _value .. .. @@ -887,6 +912,7 @@ 887 912 Specifies the value of rate of change threshold that the 888 913 device is comparing against for the events enabled by 889 914 <type>[Y][_name]_roc[_rising|falling]_en. 915 890 916 If separate attributes exist for the two directions, 891 917 but direction is not specified for this attribute, 892 918 then a single threshold value applies to both directions. .. .. @@ -969,6 +995,7 @@ 969 995 What: /sys/.../events/in_activity_jogging_thresh_falling_period 970 996 What: /sys/.../events/in_activity_running_thresh_rising_period 971 997 What: /sys/.../events/in_activity_running_thresh_falling_period 998 972 999 KernelVersion: 2.6.37 973 1000 Contact: linux-iio@vger.kernel.org 974 1001 Description: .. .. @@ -1007,7 +1034,7 @@ 1007 1034 KernelVersion: 3.19 1008 1035 Contact: linux-iio@vger.kernel.org 1009 1036 Description: 1010 1037 1011 1038 an event is generated when sensor ENTERS or LEAVES a given state. 1012 1039 1013 1040 What: /sys/.../events/in_activity_still_thresh_rising_value .. .. @@ -1285,6 +1312,7 @@ 1285 1312 Proximity measurement indicating that some 1286 1313 object is near the sensor, usually by observing 1287 1314 reflectivity of infrared or ultrasound emitted. 1315 1288 1316 Often these sensors are unit less and as such conversion 1289 1317 to SI units is not possible. Higher proximity measurements 1290 1318 indicate closer objects, and vice versa. Units after .. .. @@ -1327,6 +1355,7 @@ 1327 1355 standardised CIE Erythemal Action Spectrum. UV index values range 1328 1356 from 0 (low) to >=11 (extreme). 1329 1357 1358 1330 1359 What: /sys/.../iio:deviceX/in_intensity_red_integration_time 1331 1360 What: /sys/.../iio:deviceX/in_intensity_green_integration_time 1332 1361 What: /sys/.../iio:deviceX/in_intensity_blue_integration_time .. .. @@ -1336,7 +1365,8 @@ 1336 1365 Contact: linux-iio@vger.kernel.org 1337 1366 Description: 1338 1367 This attribute is used to get/set the integration time in 1339 1368 1369 1340 1370 1341 1371 What: /sys/.../iio:deviceX/in_velocity_sqrt(x^2+y^2+z^2)_integration_time 1342 1372 KernelVersion: 4.0 .. .. @@ -1428,9 +1458,12 @@ 1428 1458 Description: 1429 1459 A single positive integer specifying the maximum number of scan 1430 1460 elements to wait for. 1461 1431 1462 Poll will block until the watermark is reached. 1463 1432 1464 Blocking read will wait until the minimum between the requested 1433 1465 read amount or the low water mark is available. 1466 1434 1467 Non-blocking read will retrieve the available samples from the 1435 1468 buffer even if there are less samples then watermark level. This 1436 1469 allows the application to block on poll with a timeout and read .. .. @@ -1459,11 +1492,13 @@ 1459 1492 device settings allows it (e.g. if a trigger is set that samples 1460 1493 data differently that the hardware fifo does then hardware fifo 1461 1494 will not enabled). 1495 1462 1496 If the hardware fifo is enabled and the level of the hardware 1463 1497 fifo reaches the hardware fifo watermark level the device will 1464 1498 flush its hardware fifo to the device buffer. Doing a non 1465 1499 blocking read on the device when no samples are present in the 1466 1500 device buffer will also force a flush. 1501 1467 1502 When the hardware fifo is enabled there is no need to use a 1468 1503 trigger to use buffer mode since the watermark settings 1469 1504 guarantees that the hardware fifo is flushed to the device .. .. @@ -1501,6 +1536,7 @@ 1501 1536 A single positive integer specifying the minimum watermark level 1502 1537 for the hardware fifo of this device. If the device does not 1503 1538 have a hardware fifo this entry is not present. 1539 1504 1540 If the user sets buffer/watermark to a value less than this one, 1505 1541 then the hardware watermark will remain unset. 1506 1542 .. .. @@ -1511,6 +1547,7 @@ 1511 1547 A single positive integer specifying the maximum watermark level 1512 1548 for the hardware fifo of this device. If the device does not 1513 1549 have a hardware fifo this entry is not present. 1550 1514 1551 If the user sets buffer/watermark to a value greater than this 1515 1552 one, then the hardware watermark will be capped at this value. 1516 1553 .. .. @@ -1522,6 +1559,7 @@ 1522 1559 levels for the hardware fifo. This entry is optional and if it 1523 1560 is not present it means that all the values between 1524 1561 hwfifo_watermark_min and hwfifo_watermark_max are supported. 1562 1525 1563 If the user sets buffer/watermark to a value greater than 1526 1564 hwfifo_watermak_min but not equal to any of the values in this 1527 1565 list, the driver will chose an appropriate value for the .. .. @@ -1554,6 +1592,12 @@ 1554 1592 What: /sys/bus/iio/devices/iio:deviceX/in_concentrationX_raw 1555 1593 What: /sys/bus/iio/devices/iio:deviceX/in_concentration_co2_raw 1556 1594 What: /sys/bus/iio/devices/iio:deviceX/in_concentrationX_co2_raw 1595 1596 1597 1598 1599 1600 1557 1601 What: /sys/bus/iio/devices/iio:deviceX/in_concentration_voc_raw 1558 1602 What: /sys/bus/iio/devices/iio:deviceX/in_concentrationX_voc_raw 1559 1603 KernelVersion: 4.3 .. .. @@ -1577,7 +1621,8 @@ 1577 1621 Contact: linux-iio@vger.kernel.org 1578 1622 Description: 1579 1623 '1' (enable) or '0' (disable) specifying the enable 1580 1624 1625 1581 1626 This ABI is especially applicable for humidity sensors 1582 1627 to heatup the device and get rid of any condensation 1583 1628 in some humidity environment .. .. @@ -1600,17 +1645,21 @@ 1600 1645 Mounting matrix for IIO sensors. This is a rotation matrix which 1601 1646 informs userspace about sensor chip's placement relative to the 1602 1647 main hardware it is mounted on. 1648 1603 1649 Main hardware placement is defined according to the local 1604 1650 reference frame related to the physical quantity the sensor 1605 1651 measures. 1652 1606 1653 Given that the rotation matrix is defined in a board specific 1607 1654 way (platform data and / or device-tree), the main hardware 1608 1655 reference frame definition is left to the implementor's choice 1609 1656 (see below for a magnetometer example). 1657 1610 1658 Applications should apply this rotation matrix to samples so 1611 1659 that when main hardware reference frame is aligned onto local 1612 1660 reference frame, then sensor chip reference frame is also 1613 1661 perfectly aligned with it. 1662 1614 1663 Matrix is a 3x3 unitary matrix and typically looks like 1615 1664 [0, 1, 0; 1, 0, 0; 0, 0, -1]. Identity matrix 1616 1665 [1, 0, 0; 0, 1, 0; 0, 0, 1] means sensor chip and main hardware .. .. @@ -1619,8 +1668,10 @@ 1619 1668 For example, a mounting matrix for a magnetometer sensor informs 1620 1669 userspace about sensor chip's ORIENTATION relative to the main 1621 1670 hardware. 1671 1622 1672 More specifically, main hardware orientation is defined with 1623 1673 respect to the LOCAL EARTH GEOMAGNETIC REFERENCE FRAME where : 1674 1624 1675 * Y is in the ground plane and positive towards magnetic North ; 1625 1676 * X is in the ground plane, perpendicular to the North axis and 1626 1677 positive towards the East ; .. .. @@ -1629,13 +1680,16 @@ 1629 1680 An implementor might consider that for a hand-held device, a 1630 1681 'natural' orientation would be 'front facing camera at the top'. 1631 1682 The main hardware reference frame could then be described as : 1683 1632 1684 * Y is in the plane of the screen and is positive towards the 1633 1685 top of the screen ; 1634 1686 * X is in the plane of the screen, perpendicular to Y axis, and 1635 1687 positive towards the right hand side of the screen ; 1636 1688 * Z is perpendicular to the screen plane and positive out of the 1637 1689 screen. 1690 1638 1691 Another example for a quadrotor UAV might be : 1692 1639 1693 * Y is in the plane of the propellers and positive towards the 1640 1694 front-view camera; 1641 1695 * X is in the plane of the propellers, perpendicular to Y axis, .. .. @@ -1653,6 +1707,8 @@ 1653 1707 KernelVersion: 4.10 1654 1708 Contact: linux-iio@vger.kernel.org 1655 1709 Description: 1710 1711 1656 1712 Raw counter device counts from channel Y. For quadrature 1657 1713 counters, multiplication by an available [Y]_scale results in 1658 1714 the counts of a single quadrature signal phase from channel Y. .. .. @@ -1661,6 +1717,8 @@ 1661 1717 KernelVersion: 4.10 1662 1718 Contact: linux-iio@vger.kernel.org 1663 1719 Description: 1720 1721 1664 1722 Raw counter device index value from channel Y. This attribute 1665 1723 provides an absolute positional reference (e.g. a pulse once per 1666 1724 revolution) which may be used to home positional systems as .. .. @@ -1670,7 +1728,10 @@ 1670 1728 KernelVersion: 4.12 1671 1729 Contact: linux-iio@vger.kernel.org 1672 1730 Description: 1731 1732 1673 1733 A list of possible counting directions which are: 1734 1674 1735 - "up" : counter device is increasing. 1675 1736 - "down": counter device is decreasing. 1676 1737 .. .. @@ -1678,6 +1739,8 @@ 1678 1739 KernelVersion: 4.12 1679 1740 Contact: linux-iio@vger.kernel.org 1680 1741 Description: 1742 1743 1681 1744 Raw counter device counters direction for channel Y. 1682 1745 1683 1746 What: /sys/bus/iio/devices/iio:deviceX/in_phaseY_raw .. .. @@ -1685,4 +1748,57 @@ 1685 1748 Contact: linux-iio@vger.kernel.org 1686 1749 Description: 1687 1750 Raw (unscaled) phase difference reading from channel Y 1688 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804
