1. about interval:
If interval is not set, generation is increased by 1 along with
publish and copy, multi-copy is continuous.
If interval is set, pick proper samples from buffer based on
mainline/user generation, multi-copy is one-by-one.
2. about bufferpos:
user->bufferpos always point to next position to check.
data user last read
----------v--------------------------
| | | |
-------------------^-----------------
bufferpos
If buffer is full, bufferpos point to buffer.head
Examples:
If a buffer contains 4 samples, newest generatoin is 40.
-------------------------------------
|10 |20 |30 |40
------------------------------^------
|
if user's next generation is 42, notify user to copy No.40 sample,
because 42 is closer to 40 than 50.
-------------------------------------
|10 |20 |30 |40
----------------------------------^--
|
if user's next generation is 48, do not notify user,
because 48 is closer to 50, which is next mainline sample.
Signed-off-by: jihandong <jihandong@xiaomi.com>
Signed-off-by: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>
1.Allow multi users to access the same sensor device simultaneously.
2.Get real state of sensor device by cmd SNIOC_GET_STATE for users.
3.Get update state since last read by poll without timeout for users.
4.Sensor device will be activated when first user open and will close when
last user closed.
5.When multi users to access device, driver always set the minimum
sampling interval and latency to the sensor device and allow
downsampled for users above the minimum sampling interval.
6.The circbuffer will overwrite old data when buffer is full, so if users
don't read data soon, data will be lost, and the oldest data in circbuffer
are returned to the users.
7.Always read the last data in the circbuffer as initial value for new
users when the sensor device has not yet generated new data.
8.when user uses poll, if subscription interval is satisfied, the POLLIN
events is returned for each users.
9.When new user generate or the state of sensor device changed, the POLLPRI
will notify to all users.
10.Support multi advertisers to subscribe their own data as loop test.
Signed-off-by: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>
1.Simplify buffer opeations to avoid frequent resize for batch and no-batch mode.
2.When sensor event is first generated, the buffer is initialized.
3.Remove and merge batch_number to buffer_number when device support batch mode.
Signed-off-by: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>
complete the following commits:
commit d87cf8d4ca
Author: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>
Date: Fri Apr 1 20:59:55 2022 +0800
fs/poll: change format for type pollevent_t
Signed-off-by: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>
commit d535943a69
Author: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>
Date: Fri Apr 1 17:49:10 2022 +0800
fs/epoll: change type of eventset from uint8_t to uint32_t
to support EPOLLONESHOT and so on.
Signed-off-by: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>
Signed-off-by: chao.an <anchao@xiaomi.com>
Some PPG devices have 4 ADCs to output quad-channel PPG values while some of them only have 2 ADCs to output dual-channel PPG.
To deal the case above, the type PPGD(PPG of Dual-channel) takes the place of former type PPG, which also have 2-channel PPG outputs. Type PPGQ (PPG of Quad-channel) is new for 4-ADC-PPG. Both types have contained new data "gain" to indicate ADC gains of each PPG channel, for the reason that the gains may vary during automatical optical adjustments.
Signed-off-by: liucheng5 <liucheng5@xiaomi.com>
1.use userspace buffer rather than intermediate buffer of upperhalf driver
2.support block and non-block ways.
Change-Id: I1d0cecfaa20ce54961c58713d8f2f8857e349791
Signed-off-by: dongjiuzhu <dongjiuzhu1@xiaomi.com>
1.support for multi-user access
2.support special cmd to control sensor
3.support userspace to set size of intermediate buffer
by ioctl: SNOIC_SET_BUFFER_SIZE
Change-Id: I9ce3a65b88b12c28388ec397431f1a277b120c2a
Signed-off-by: dongjiuzhu <dongjiuzhu1@xiaomi.com>
