[PATCH v4 0/7] Intel Integrated Sensor Hub Support (ISH)

STALE3648d

Revision v4 of 3 in this series.

6 messages, 2 authors, 2016-08-07 · open the first message on its own page

[PATCH v4 0/7] Intel Integrated Sensor Hub Support (ISH)

From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Date: 2016-08-07 09:25:46

Change log
v4:
- Replace Bus PM suspend/resume callbacks to pm_ops calls to support callbacks from hibernate as pointer by Rafael
- Fix kernel doc style comments: Now every function has kernel doc header
- All checkpatch errors are resolved
- Function returning just a single value with no users of return value to void
- reference_count in struct ishtp_cl_device changed to bool as pointed by Ooi, Joyce
- auto module load glue logic as suggested by Ooi, Joyce
- Fix possible kernel warnings during module removal in ishtp
- Remove devices during ish-pci module removal
- Add Original-author tag
- Add MAINTAINER entry

v3:
- Rebased to linux-next as there are some new bus ids are added to linux-next
- Documentation changes suggested by Jonathan
- The PCI device name for BXTP is changed to APL
- Added module parameter to enable DMA as some older FW
have issues in DMA support.
- On resume just restart to resume faster insted of reset for
S3 compliant platforms

Thanks to Grant Likely and Atri Bhattacharya, Rann Bar and Ooi Joyce for test. 
I will add Tested-by to commits for the final version of the patches.

v2:
- Overview in documentation show analogy with usbhid implementation
- sparse errors for statics. Also pointed by Jiri
- Clearly marking exported function header file. Clean up all exports
unused inteface functions
- Changed to tristate from boolean as pointed by Jiri:
this required remove/unload functions
- Prevent crash when ISH enabled on non supported platform
- Break client.c to smaller part by seprating buffer allocations
- move bus register/unregister to ishtp module
- There is only one config symbol INTEL_ISH_HID, removed silent
config for TRANSPORT and IPC


Starting from Cherrytrail, multiple generation of Intel processors offers
on package sensor hub. Several recent tablets, 2-in-1 convertible laptops
are using ISH instead of external sensor hubs. This resulted in lack of
support of sensor function like device rotation and auto backlight
adjustment.
In addition, depending on the OEM implementation, support of ISH is required
to support low power sleep states.

The support of ISH on Linux platforms is not new. Android platforms with
Intel SoCs had this support for a while submitted by Daniel Drubin. 
This patcheset is reusing most of those changes with  clean up and
removing Android platform specific changes.

The user mode ABI is still same as external sensor hubs using Linux
IIO. So existing user mode software should still work.
This series primarily brings in new HID transport used in ISH.

Thanks to the community members who tested RFC patches and provided
feedback.

For users testing on Linux distributions using IIO sensor proxy,
a short term work around is required till we have debugged this issue.
In systemd unit file iio-sensor-proxy.service
In the section "[Unit]" add
After=multi-user.target

Srinivas Pandruvada (7):
  Documentation: hid: Intel ISH HID document
  hid: intel_ish-hid: ISH Transport layer
  hid: intel-ish-hid: ipc layer
  hid: intel-ish-hid: ISH HID client driver
  iio: hid-sensors: use asynchronous resume
  hid: hid-sensor-hub: Add ISH quirk
  MAINTAINERS: Add Intel ISH

 Documentation/hid/intel-ish-hid.txt                |  454 +++++++++
 MAINTAINERS                                        |    7 +
 drivers/hid/Kconfig                                |    2 +
 drivers/hid/Makefile                               |    2 +
 drivers/hid/hid-sensor-hub.c                       |    4 +
 drivers/hid/intel-ish-hid/Kconfig                  |   17 +
 drivers/hid/intel-ish-hid/Makefile                 |   22 +
 drivers/hid/intel-ish-hid/ipc/hw-ish-regs.h        |  220 ++++
 drivers/hid/intel-ish-hid/ipc/hw-ish.h             |   71 ++
 drivers/hid/intel-ish-hid/ipc/ipc.c                |  882 ++++++++++++++++
 drivers/hid/intel-ish-hid/ipc/pci-ish.c            |  333 +++++++
 drivers/hid/intel-ish-hid/ipc/utils.h              |   64 ++
 drivers/hid/intel-ish-hid/ishtp-hid-client.c       |  978 ++++++++++++++++++
 drivers/hid/intel-ish-hid/ishtp-hid.c              |  246 +++++
 drivers/hid/intel-ish-hid/ishtp-hid.h              |  182 ++++
 drivers/hid/intel-ish-hid/ishtp/bus.c              |  791 +++++++++++++++
 drivers/hid/intel-ish-hid/ishtp/bus.h              |  114 +++
 drivers/hid/intel-ish-hid/ishtp/client-buffers.c   |  258 +++++
 drivers/hid/intel-ish-hid/ishtp/client.c           | 1054 ++++++++++++++++++++
 drivers/hid/intel-ish-hid/ishtp/client.h           |  182 ++++
 drivers/hid/intel-ish-hid/ishtp/dma-if.c           |  175 ++++
 drivers/hid/intel-ish-hid/ishtp/hbm.c              | 1032 +++++++++++++++++++
 drivers/hid/intel-ish-hid/ishtp/hbm.h              |  321 ++++++
 drivers/hid/intel-ish-hid/ishtp/init.c             |  115 +++
 drivers/hid/intel-ish-hid/ishtp/ishtp-dev.h        |  277 +++++
 .../iio/common/hid-sensors/hid-sensor-trigger.c    |   21 +-
 include/linux/hid-sensor-hub.h                     |    1 +
 include/trace/events/intel_ish.h                   |   30 +
 include/uapi/linux/input.h                         |    1 +
 29 files changed, 7855 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/hid/intel-ish-hid.txt
 create mode 100644 drivers/hid/intel-ish-hid/Kconfig
 create mode 100644 drivers/hid/intel-ish-hid/Makefile
 create mode 100644 drivers/hid/intel-ish-hid/ipc/hw-ish-regs.h
 create mode 100644 drivers/hid/intel-ish-hid/ipc/hw-ish.h
 create mode 100644 drivers/hid/intel-ish-hid/ipc/ipc.c
 create mode 100644 drivers/hid/intel-ish-hid/ipc/pci-ish.c
 create mode 100644 drivers/hid/intel-ish-hid/ipc/utils.h
 create mode 100644 drivers/hid/intel-ish-hid/ishtp-hid-client.c
 create mode 100644 drivers/hid/intel-ish-hid/ishtp-hid.c
 create mode 100644 drivers/hid/intel-ish-hid/ishtp-hid.h
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/bus.c
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/bus.h
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/client-buffers.c
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/client.c
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/client.h
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/dma-if.c
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/hbm.c
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/hbm.h
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/init.c
 create mode 100644 drivers/hid/intel-ish-hid/ishtp/ishtp-dev.h
 create mode 100644 include/trace/events/intel_ish.h

-- 
2.7.4

[PATCH v4 1/7] Documentation: hid: Intel ISH HID document

From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Date: 2016-08-07 09:25:47

Document explaining ISH HID operation and implementation.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 Documentation/hid/intel-ish-hid.txt | 454 ++++++++++++++++++++++++++++++++++++
 1 file changed, 454 insertions(+)
 create mode 100644 Documentation/hid/intel-ish-hid.txt
diff --git a/Documentation/hid/intel-ish-hid.txt b/Documentation/hid/intel-ish-hid.txt
new file mode 100644
index 0000000..d48b21c
--- /dev/null
+++ b/Documentation/hid/intel-ish-hid.txt
@@ -0,0 +1,454 @@
+Intel Integrated Sensor Hub (ISH)
+===============================
+
+A sensor hub enables the ability to offload sensor polling and algorithm
+processing to a dedicated low power co-processor. This allows the core
+processor to go into low power modes more often, resulting in the increased
+battery life.
+
+There are many vendors providing external sensor hubs confirming to HID
+Sensor usage tables, and used in several tablets, 2 in 1 convertible laptops
+and embedded products. Linux had this support since Linux 3.9.
+
+Intel® introduced integrated sensor hubs as a part of the SoC starting from
+Cherry Trail and now supported on multiple generations of CPU packages. There
+are many commercial devices already shipped with Integrated Sensor Hubs (ISH).
+These ISH also comply to HID sensor specification, but the  difference is the
+transport protocol used for communication. The current external sensor hubs
+mainly use HID over i2C or USB. But ISH doesn't use either i2c or USB.
+
+1. Overview
+
+Using a analogy with a usbhid implementation, the ISH follows a similar model
+for a very high speed communication:
+
+	-----------------		----------------------
+	|    USB HID	|	-->	|    ISH HID	     |
+	-----------------		----------------------
+	-----------------		----------------------
+	|  USB protocol	|	-->	|    ISH Transport   |
+	-----------------		----------------------
+	-----------------		----------------------
+	|  EHCI/XHCI	|	-->	|    ISH IPC	     |
+	-----------------		----------------------
+	      PCI				 PCI
+	-----------------		----------------------
+        |Host controller|	-->	|    ISH processor   |
+	-----------------		----------------------
+	     USB Link
+	-----------------		----------------------
+	| USB End points|	-->	|    ISH Clients     |
+	-----------------		----------------------
+
+Like USB protocol provides a method for device enumeration, link management
+and user data encapsulation, the ISH also provides similar services. But it is
+very light weight tailored to manage and communicate with ISH client
+applications implemented in the firmware.
+
+The ISH allows multiple sensor management applications executing in the
+firmware. Like USB endpoints the messaging can be to/from a client. As part of
+enumeration process, these clients are identified. These clients can be simple
+HID sensor applications, sensor calibration application or senor firmware
+update application.
+
+The implementation model is similar, like USB bus, ISH transport is also
+implemented as a bus. Each client application executing in the ISH processor
+is registered as a device on this bus. The driver, which binds each device
+(ISH HID driver) identifies the device type and registers with the hid core.
+
+2. ISH Implementation: Block Diagram
+
+	 ---------------------------
+	|  User Space Applications  |
+	 ---------------------------
+
+----------------IIO ABI----------------
+	 --------------------------
+	|  IIO Sensor Drivers	  |
+	 --------------------------
+	 --------------------------
+	|	 IIO core	  |
+	 --------------------------
+	 --------------------------
+	|   HID Sensor Hub MFD	  |
+	 --------------------------
+	 --------------------------
+	|       HID Core	  |
+	 --------------------------
+	 --------------------------
+	|   HID over ISH Client   |
+	 --------------------------
+	 --------------------------
+	|   ISH Transport (ISHTP) |
+	 --------------------------
+	 --------------------------
+	|      IPC Drivers	  |
+	 --------------------------
+OS
+----------------   PCI -----------------
+Hardware + Firmware
+	 ----------------------------
+	| ISH Hardware/Firmware(FW) |
+	 ----------------------------
+
+3. High level processing in above blocks
+
+3.1 Hardware Interface
+
+The ISH is exposed as "Non-VGA unclassified PCI device" to the host. The PCI
+product and vendor IDs are changed from different generations of processors. So
+the source code which enumerate drivers needs to update from generation to
+generation.
+
+3.2 Inter Processor Communication (IPC) driver
+Location: drivers/hid/intel-ish-hid/ipc
+
+The IPC message used memory mapped I/O. The registers are defined in
+hw-ish-regs.h.
+
+3.2.1 IPC/FW message types
+
+There are two types of messages, one for management of link and other messages
+are to and from transport layers.
+
+TX and RX of Transport messages
+
+A set of memory mapped register offers support of multi byte messages TX and
+RX (E.g.IPC_REG_ISH2HOST_MSG, IPC_REG_HOST2ISH_MSG). The IPC layer maintains
+internal queues to sequence messages and send them in order to the FW.
+Optionally the caller can register handler to get notification of completion.
+A door bell mechanism is used in messaging to trigger processing in host and
+client firmware side. When ISH interrupt handler is called, the ISH2HOST
+doorbell register is used by host drivers to determine that the interrupt
+is for ISH.
+
+Each side has 32 32-bit message registers and a 32-bit doorbell. Doorbell
+register has the following format:
+Bits 0..6: fragment length (7 bits are used)
+Bits 10..13: encapsulated protocol
+Bits 16..19: management command (for IPC management protocol)
+Bit 31: doorbell trigger (signal H/W interrupt to the other side)
+Other bits are reserved, should be 0.
+
+3.2.2 Transport layer interface
+
+To abstract HW level IPC communication, a set of callbacks are registered.
+The transport layer uses them to send and receive messages.
+Refer to  struct ishtp_hw_ops for callbacks.
+
+3.3 ISH Transport layer
+Location: drivers/hid/intel-ish-hid/ishtp/
+
+3.3.1 A Generic Transport Layer
+
+The transport layer is a bi-directional protocol, which defines:
+- Set of commands to start, stop, connect, disconnect and flow control
+(ishtp/hbm.h) for details
+- A flow control mechanism to avoid buffer overflows
+
+This protocol resembles bus messages described in the following document:
+http://www.intel.com/content/dam/www/public/us/en/documents/technical-\
+specifications/dcmi-hi-1-0-spec.pdf "Chapter 7: Bus Message Layer"
+
+3.3.2 Connection and Flow Control Mechanism
+
+Each FW client and a protocol is identified by an UUID. In order to communicate
+to a FW client, a connection must be established using connect request and
+response bus messages. If successful, a pair (host_client_id and fw_client_id)
+will identify the connection.
+
+Once connection is established, peers send each other flow control bus messages
+independently. Every peer may send a message only if it has received a
+flow-control credit before. Once it sent a message, it may not send another one
+before receiving the next flow control credit.
+Either side can send disconnect request bus message to end communication. Also
+the link will be dropped if major FW reset occurs.
+
+3.3.3 Peer to Peer data transfer
+
+Peer to Peer data transfer can happen with or without using DMA. Depending on
+the sensor bandwidth requirement DMA can be enabled by using module parameter
+ishtp_use_dma under intel_ishtp.
+
+Each side (host and FW) manages its DMA transfer memory independently. When an
+ISHTP client from either host or FW side wants to send something, it decides
+whether to send over IPC or over DMA; for each transfer the decision is
+independent. The sending side sends DMA_XFER message when the message is in
+the respective host buffer (TX when host client sends, RX when FW client
+sends). The recipient of DMA message responds with DMA_XFER_ACK, indicating
+the sender that the memory region for that message may be reused.
+
+DMA initialization is started with host sending DMA_ALLOC_NOTIFY bus message
+(that includes RX buffer) and FW responds with DMA_ALLOC_NOTIFY_ACK.
+Additionally to DMA address communication, this sequence checks capabilities:
+if thw host doesn't support DMA, then it won't send DMA allocation, so FW can't
+send DMA; if FW doesn't support DMA then it won't respond with
+DMA_ALLOC_NOTIFY_ACK, in which case host will not use DMA transfers.
+Here ISH acts as busmaster DMA controller. Hence when host sends DMA_XFER,
+it's request to do host->ISH DMA transfer; when FW sends DMA_XFER, it means
+that it already did DMA and the message resides at host. Thus, DMA_XFER
+and DMA_XFER_ACK act as ownership indicators.
+
+At initial state all outgoing memory belongs to the sender (TX to host, RX to
+FW), DMA_XFER transfers ownership on the region that contains ISHTP message to
+the receiving side, DMA_XFER_ACK returns ownership to the sender. A sender
+needs not wait for previous DMA_XFER to be ack'ed, and may send another message
+as long as remaining continuous memory in its ownership is enough.
+In principle, multiple DMA_XFER and DMA_XFER_ACK messages may be sent at once
+(up to IPC MTU), thus allowing for interrupt throttling.
+Currently, ISH FW decides to send over DMA if ISHTP message is more than 3 IPC
+fragments and via IPC otherwise.
+
+3.3.4 Ring Buffers
+
+When a client initiate a connection, a ring or RX and TX buffers are allocated.
+The size of ring can be specified by the client. HID client set 16 and 32 for
+TX and RX buffers respectively. On send request from client, the data to be
+sent is copied to one of the send ring buffer and scheduled to be sent using
+bus message protocol. These buffers are required because the FW may have not
+have processed the last message and may not have enough flow control credits
+to send. Same thing holds true on receive side and flow control is required.
+
+3.3.5 Host Enumeration
+
+The host enumeration bus command allow discovery of clients present in the FW.
+There can be multiple sensor clients and clients for calibration function.
+
+To ease in implantation and allow independent driver handle each client
+this transport layer takes advantage of Linux Bus driver model. Each
+client is registered as device on the the transport bus (ishtp bus).
+
+Enumeration sequence of messages:
+- Host sends HOST_START_REQ_CMD, indicating that host ISHTP layer is up.
+- FW responds with HOST_START_RES_CMD
+- Host sends HOST_ENUM_REQ_CMD (enumerate FW clients)
+- FW responds with HOST_ENUM_RES_CMD that includes bitmap of available FW
+client IDs
+- For each FW ID found in that bitmap host sends
+HOST_CLIENT_PROPERTIES_REQ_CMD
+- FW responds with HOST_CLIENT_PROPERTIES_RES_CMD. Properties include UUID,
+max ISHTP message size, etc.
+- Once host received properties for that last discovered client, it considers
+ISHTP device fully functional (and allocates DMA buffers)
+
+3.4 HID over ISH Client
+Location: drivers/hid/intel-ish-hid
+
+The ISHTP client driver is responsible for:
+- enumerate HID devices under FW ISH client
+- Get Report descriptor
+- Register with HID core as a LL driver
+- Process Get/Set feature request
+- Get input reports
+
+3.5 HID Sensor Hub MFD and IIO sensor drivers
+
+The functionality in these drivers is the same as an external sensor hub.
+Refer to
+Documentation/hid/hid-sensor.txt for HID sensor
+Documentation/ABI/testing/sysfs-bus-iio for IIO ABIs to user space
+
+3.6 End to End HID transport Sequence Diagram
+
+HID-ISH-CLN			ISHTP			IPC				HW
+	|			|			|				|
+	|			|			|-----WAKE UP------------------>|
+	|			|			|				|
+	|			|			|-----HOST READY--------------->|
+	|			|			|				|
+	|			|			|<----MNG_RESET_NOTIFY_ACK----- |
+	|			|			|				|
+	|			|<----ISHTP_START------ |				|
+	|			|			|				|
+	|			|<-----------------HOST_START_RES_CMD-------------------|
+	|			|			|				|
+	|			|------------------QUERY_SUBSCRIBER-------------------->|
+	|			|			|				|
+	|			|------------------HOST_ENUM_REQ_CMD------------------->|
+	|			|			|				|
+	|			|<-----------------HOST_ENUM_RES_CMD--------------------|
+	|			|			|				|
+	|			|------------------HOST_CLIENT_PROPERTIES_REQ_CMD------>|
+	|			|			|				|
+	|			|<-----------------HOST_CLIENT_PROPERTIES_RES_CMD-------|
+	|	Create new device on in ishtp bus	|				|
+	|			|			|				|
+	|			|------------------HOST_CLIENT_PROPERTIES_REQ_CMD------>|
+	|			|			|				|
+	|			|<-----------------HOST_CLIENT_PROPERTIES_RES_CMD-------|
+	|	Create new device on in ishtp bus	|				|
+	|			|			|				|
+	|			|--Repeat HOST_CLIENT_PROPERTIES_REQ_CMD-till last one--|
+	|			|			|				|
+     probed()
+	|----ishtp_cl_connect-->|----------------- CLIENT_CONNECT_REQ_CMD-------------->|
+	|			|			|				|
+	|			|<----------------CLIENT_CONNECT_RES_CMD----------------|
+	|			|			|				|
+	|register event callback|			|				|
+	|			|			|				|
+	|ishtp_cl_send(
+	HOSTIF_DM_ENUM_DEVICES) |----------fill ishtp_msg_hdr struct write to HW-----  >|
+	|			|			|				|
+	|			|			|<-----IRQ(IPC_PROTOCOL_ISHTP---|
+	|			|			|				|
+	|<--ENUM_DEVICE RSP-----|			|				|
+	|			|			|				|
+for each enumerated device
+	|ishtp_cl_send(
+	HOSTIF_GET_HID_DESCRIPTOR |----------fill ishtp_msg_hdr struct write to HW---  >|
+	|			|			|				|
+	...Response
+	|			|			|				|
+for each enumerated device
+	|ishtp_cl_send(
+	HOSTIF_GET_REPORT_DESCRIPTOR |----------fill ishtp_msg_hdr struct write to HW- >|
+	|			|			|				|
+	|			|			|				|
+ hid_allocate_device
+	|			|			|				|
+ hid_add_device			|			|				|
+	|			|			|				|
+
+
+3.7 ISH Debugging
+
+To debug ISH, event tracing mechanism is used. To enable debug logs
+echo 1 > /sys/kernel/debug/tracing/events/intel_ish/enable
+cat sys/kernel/debug/tracing/trace
+
+3.8 ISH IIO sysfs Example on Lenovo thinkpad Yoga 260
+
+root@otcpl-ThinkPad-Yoga-260:~# tree -l /sys/bus/iio/devices/
+/sys/bus/iio/devices/
+├── iio:device0 -> ../../../devices/0044:8086:22D8.0001/HID-SENSOR-200073.9.auto/iio:device0
+│   ├── buffer
+│   │   ├── enable
+│   │   ├── length
+│   │   └── watermark
+...
+│   ├── in_accel_hysteresis
+│   ├── in_accel_offset
+│   ├── in_accel_sampling_frequency
+│   ├── in_accel_scale
+│   ├── in_accel_x_raw
+│   ├── in_accel_y_raw
+│   ├── in_accel_z_raw
+│   ├── name
+│   ├── scan_elements
+│   │   ├── in_accel_x_en
+│   │   ├── in_accel_x_index
+│   │   ├── in_accel_x_type
+│   │   ├── in_accel_y_en
+│   │   ├── in_accel_y_index
+│   │   ├── in_accel_y_type
+│   │   ├── in_accel_z_en
+│   │   ├── in_accel_z_index
+│   │   └── in_accel_z_type
+...
+│   │   ├── devices
+│   │   │   │   ├── buffer
+│   │   │   │   │   ├── enable
+│   │   │   │   │   ├── length
+│   │   │   │   │   └── watermark
+│   │   │   │   ├── dev
+│   │   │   │   ├── in_intensity_both_raw
+│   │   │   │   ├── in_intensity_hysteresis
+│   │   │   │   ├── in_intensity_offset
+│   │   │   │   ├── in_intensity_sampling_frequency
+│   │   │   │   ├── in_intensity_scale
+│   │   │   │   ├── name
+│   │   │   │   ├── scan_elements
+│   │   │   │   │   ├── in_intensity_both_en
+│   │   │   │   │   ├── in_intensity_both_index
+│   │   │   │   │   └── in_intensity_both_type
+│   │   │   │   ├── trigger
+│   │   │   │   │   └── current_trigger
+...
+│   │   │   │   ├── buffer
+│   │   │   │   │   ├── enable
+│   │   │   │   │   ├── length
+│   │   │   │   │   └── watermark
+│   │   │   │   ├── dev
+│   │   │   │   ├── in_magn_hysteresis
+│   │   │   │   ├── in_magn_offset
+│   │   │   │   ├── in_magn_sampling_frequency
+│   │   │   │   ├── in_magn_scale
+│   │   │   │   ├── in_magn_x_raw
+│   │   │   │   ├── in_magn_y_raw
+│   │   │   │   ├── in_magn_z_raw
+│   │   │   │   ├── in_rot_from_north_magnetic_tilt_comp_raw
+│   │   │   │   ├── in_rot_hysteresis
+│   │   │   │   ├── in_rot_offset
+│   │   │   │   ├── in_rot_sampling_frequency
+│   │   │   │   ├── in_rot_scale
+│   │   │   │   ├── name
+...
+│   │   │   │   ├── scan_elements
+│   │   │   │   │   ├── in_magn_x_en
+│   │   │   │   │   ├── in_magn_x_index
+│   │   │   │   │   ├── in_magn_x_type
+│   │   │   │   │   ├── in_magn_y_en
+│   │   │   │   │   ├── in_magn_y_index
+│   │   │   │   │   ├── in_magn_y_type
+│   │   │   │   │   ├── in_magn_z_en
+│   │   │   │   │   ├── in_magn_z_index
+│   │   │   │   │   ├── in_magn_z_type
+│   │   │   │   │   ├── in_rot_from_north_magnetic_tilt_comp_en
+│   │   │   │   │   ├── in_rot_from_north_magnetic_tilt_comp_index
+│   │   │   │   │   └── in_rot_from_north_magnetic_tilt_comp_type
+│   │   │   │   ├── trigger
+│   │   │   │   │   └── current_trigger
+...
+│   │   │   │   ├── buffer
+│   │   │   │   │   ├── enable
+│   │   │   │   │   ├── length
+│   │   │   │   │   └── watermark
+│   │   │   │   ├── dev
+│   │   │   │   ├── in_anglvel_hysteresis
+│   │   │   │   ├── in_anglvel_offset
+│   │   │   │   ├── in_anglvel_sampling_frequency
+│   │   │   │   ├── in_anglvel_scale
+│   │   │   │   ├── in_anglvel_x_raw
+│   │   │   │   ├── in_anglvel_y_raw
+│   │   │   │   ├── in_anglvel_z_raw
+│   │   │   │   ├── name
+│   │   │   │   ├── scan_elements
+│   │   │   │   │   ├── in_anglvel_x_en
+│   │   │   │   │   ├── in_anglvel_x_index
+│   │   │   │   │   ├── in_anglvel_x_type
+│   │   │   │   │   ├── in_anglvel_y_en
+│   │   │   │   │   ├── in_anglvel_y_index
+│   │   │   │   │   ├── in_anglvel_y_type
+│   │   │   │   │   ├── in_anglvel_z_en
+│   │   │   │   │   ├── in_anglvel_z_index
+│   │   │   │   │   └── in_anglvel_z_type
+│   │   │   │   ├── trigger
+│   │   │   │   │   └── current_trigger
+...
+│   │   │   │   ├── buffer
+│   │   │   │   │   ├── enable
+│   │   │   │   │   ├── length
+│   │   │   │   │   └── watermark
+│   │   │   │   ├── dev
+│   │   │   │   ├── in_anglvel_hysteresis
+│   │   │   │   ├── in_anglvel_offset
+│   │   │   │   ├── in_anglvel_sampling_frequency
+│   │   │   │   ├── in_anglvel_scale
+│   │   │   │   ├── in_anglvel_x_raw
+│   │   │   │   ├── in_anglvel_y_raw
+│   │   │   │   ├── in_anglvel_z_raw
+│   │   │   │   ├── name
+│   │   │   │   ├── scan_elements
+│   │   │   │   │   ├── in_anglvel_x_en
+│   │   │   │   │   ├── in_anglvel_x_index
+│   │   │   │   │   ├── in_anglvel_x_type
+│   │   │   │   │   ├── in_anglvel_y_en
+│   │   │   │   │   ├── in_anglvel_y_index
+│   │   │   │   │   ├── in_anglvel_y_type
+│   │   │   │   │   ├── in_anglvel_z_en
+│   │   │   │   │   ├── in_anglvel_z_index
+│   │   │   │   │   └── in_anglvel_z_type
+│   │   │   │   ├── trigger
+│   │   │   │   │   └── current_trigger
+...
-- 
2.7.4

[PATCH v4 3/7] hid: intel-ish-hid: ipc layer

From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Date: 2016-08-07 09:25:49

This layer is responsible for
- Enumerating over PCI bus
- Inform FW about host readiness
- Provide HW interface to transport layer for control and messages
- Interrupt handling and routing

Original-author: Daniel Drubin [off-list ref]
Reviewed-and-tested-by: Ooi, Joyce [off-list ref]
Tested-by: Grant Likely <redacted>
Tested-by: Rann Bar-On <redacted>
Tested-by: Atri Bhattacharya <redacted>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/hid/intel-ish-hid/Makefile          |   6 +
 drivers/hid/intel-ish-hid/ipc/hw-ish-regs.h | 220 +++++++
 drivers/hid/intel-ish-hid/ipc/hw-ish.h      |  71 +++
 drivers/hid/intel-ish-hid/ipc/ipc.c         | 882 ++++++++++++++++++++++++++++
 drivers/hid/intel-ish-hid/ipc/pci-ish.c     | 333 +++++++++++
 drivers/hid/intel-ish-hid/ipc/utils.h       |  64 ++
 include/trace/events/intel_ish.h            |  30 +
 7 files changed, 1606 insertions(+)
 create mode 100644 drivers/hid/intel-ish-hid/ipc/hw-ish-regs.h
 create mode 100644 drivers/hid/intel-ish-hid/ipc/hw-ish.h
 create mode 100644 drivers/hid/intel-ish-hid/ipc/ipc.c
 create mode 100644 drivers/hid/intel-ish-hid/ipc/pci-ish.c
 create mode 100644 drivers/hid/intel-ish-hid/ipc/utils.h
 create mode 100644 include/trace/events/intel_ish.h
diff --git a/drivers/hid/intel-ish-hid/Makefile b/drivers/hid/intel-ish-hid/Makefile
index 7b32d49..ab626d8 100644
--- a/drivers/hid/intel-ish-hid/Makefile
+++ b/drivers/hid/intel-ish-hid/Makefile
@@ -10,3 +10,9 @@ intel-ishtp-objs += ishtp/client.o
 intel-ishtp-objs += ishtp/bus.o
 intel-ishtp-objs += ishtp/dma-if.o
 intel-ishtp-objs += ishtp/client-buffers.o
+
+obj-$(CONFIG_INTEL_ISH_HID) += intel-ish-ipc.o
+intel-ish-ipc-objs := ipc/ipc.o
+intel-ish-ipc-objs += ipc/pci-ish.o
+
+ccflags-y += -Idrivers/hid/intel-ish-hid/ishtp
diff --git a/drivers/hid/intel-ish-hid/ipc/hw-ish-regs.h b/drivers/hid/intel-ish-hid/ipc/hw-ish-regs.h
new file mode 100644
index 0000000..ab68afc
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ipc/hw-ish-regs.h
@@ -0,0 +1,220 @@
+/*
+ * ISH registers definitions
+ *
+ * Copyright (c) 2012-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef _ISHTP_ISH_REGS_H_
+#define _ISHTP_ISH_REGS_H_
+
+
+/*** IPC PCI Offsets and sizes ***/
+/* ISH IPC Base Address */
+#define IPC_REG_BASE		0x0000
+/* Peripheral Interrupt Status Register */
+#define IPC_REG_PISR_CHV_AB      (IPC_REG_BASE + 0x00)
+/* Peripheral Interrupt Mask Register */
+#define IPC_REG_PIMR_CHV_AB      (IPC_REG_BASE + 0x04)
+/*BXT, CHV_K0*/
+/*Peripheral Interrupt Status Register */
+#define IPC_REG_PISR_BXT	 (IPC_REG_BASE + 0x0C)
+/*Peripheral Interrupt Mask Register */
+#define IPC_REG_PIMR_BXT	 (IPC_REG_BASE + 0x08)
+/***********************************/
+/* ISH Host Firmware status Register */
+#define IPC_REG_ISH_HOST_FWSTS	(IPC_REG_BASE + 0x34)
+/* Host Communication Register */
+#define IPC_REG_HOST_COMM	(IPC_REG_BASE + 0x38)
+/* Reset register */
+#define IPC_REG_ISH_RST		(IPC_REG_BASE + 0x44)
+
+/* Inbound doorbell register Host to ISH */
+#define IPC_REG_HOST2ISH_DRBL	(IPC_REG_BASE + 0x48)
+/* Outbound doorbell register ISH to Host */
+#define IPC_REG_ISH2HOST_DRBL	(IPC_REG_BASE + 0x54)
+/* ISH to HOST message registers */
+#define IPC_REG_ISH2HOST_MSG	(IPC_REG_BASE + 0x60)
+/* HOST to ISH message registers */
+#define IPC_REG_HOST2ISH_MSG	(IPC_REG_BASE + 0xE0)
+/* REMAP2 to enable DMA (D3 RCR) */
+#define	IPC_REG_ISH_RMP2	(IPC_REG_BASE + 0x368)
+
+#define	IPC_REG_MAX		(IPC_REG_BASE + 0x400)
+
+/*** register bits - HISR ***/
+/* bit corresponds HOST2ISH interrupt in PISR and PIMR registers */
+#define IPC_INT_HOST2ISH_BIT            (1<<0)
+/***********************************/
+/*CHV_A0, CHV_B0*/
+/* bit corresponds ISH2HOST interrupt in PISR and PIMR registers */
+#define IPC_INT_ISH2HOST_BIT_CHV_AB	(1<<3)
+/*BXT, CHV_K0*/
+/* bit corresponds ISH2HOST interrupt in PISR and PIMR registers */
+#define IPC_INT_ISH2HOST_BIT_BXT	(1<<0)
+/***********************************/
+
+/* bit corresponds ISH2HOST busy clear interrupt in PIMR register */
+#define IPC_INT_ISH2HOST_CLR_MASK_BIT	(1<<11)
+
+/* offset of ISH2HOST busy clear interrupt in IPC_BUSY_CLR register */
+#define IPC_INT_ISH2HOST_CLR_OFFS	(0)
+
+/* bit corresponds ISH2HOST busy clear interrupt in IPC_BUSY_CLR register */
+#define IPC_INT_ISH2HOST_CLR_BIT	(1<<IPC_INT_ISH2HOST_CLR_OFFS)
+
+/* bit corresponds busy bit in doorbell registers */
+#define IPC_DRBL_BUSY_OFFS		(31)
+#define IPC_DRBL_BUSY_BIT		(1<<IPC_DRBL_BUSY_OFFS)
+
+#define	IPC_HOST_OWNS_MSG_OFFS		(30)
+
+/*
+ * A0: bit means that host owns MSGnn registers and is reading them.
+ * ISH FW may not write to them
+ */
+#define	IPC_HOST_OWNS_MSG_BIT		(1<<IPC_HOST_OWNS_MSG_OFFS)
+
+/*
+ * Host status bits (HOSTCOMM)
+ */
+/* bit corresponds host ready bit in Host Status Register (HOST_COMM) */
+#define IPC_HOSTCOMM_READY_OFFS		(7)
+#define IPC_HOSTCOMM_READY_BIT		(1<<IPC_HOSTCOMM_READY_OFFS)
+
+/***********************************/
+/*CHV_A0, CHV_B0*/
+#define	IPC_HOSTCOMM_INT_EN_OFFS_CHV_AB	(31)
+#define	IPC_HOSTCOMM_INT_EN_BIT_CHV_AB		\
+	(1<<IPC_HOSTCOMM_INT_EN_OFFS_CHV_AB)
+/*BXT, CHV_K0*/
+#define IPC_PIMR_INT_EN_OFFS_BXT	(0)
+#define IPC_PIMR_INT_EN_BIT_BXT		(1<<IPC_PIMR_INT_EN_OFFS_BXT)
+
+#define IPC_HOST2ISH_BUSYCLEAR_MASK_OFFS_BXT	(8)
+#define IPC_HOST2ISH_BUSYCLEAR_MASK_BIT		\
+	(1<<IPC_HOST2ISH_BUSYCLEAR_MASK_OFFS_BXT)
+/***********************************/
+/*
+ * both Host and ISH have ILUP at bit 0
+ * bit corresponds host ready bit in both status registers
+ */
+#define IPC_ILUP_OFFS			(0)
+#define IPC_ILUP_BIT			(1<<IPC_ILUP_OFFS)
+
+/*
+ * FW status bits (relevant)
+ */
+#define	IPC_FWSTS_ILUP		0x1
+#define	IPC_FWSTS_ISHTP_UP	(1<<1)
+#define	IPC_FWSTS_DMA0		(1<<16)
+#define	IPC_FWSTS_DMA1		(1<<17)
+#define	IPC_FWSTS_DMA2		(1<<18)
+#define	IPC_FWSTS_DMA3		(1<<19)
+
+#define	IPC_ISH_IN_DMA		\
+	(IPC_FWSTS_DMA0 | IPC_FWSTS_DMA1 | IPC_FWSTS_DMA2 | IPC_FWSTS_DMA3)
+
+/* bit corresponds host ready bit in ISH FW Status Register */
+#define IPC_ISH_ISHTP_READY_OFFS		(1)
+#define IPC_ISH_ISHTP_READY_BIT		(1<<IPC_ISH_ISHTP_READY_OFFS)
+
+#define	IPC_RMP2_DMA_ENABLED	0x1	/* Value to enable DMA, per D3 RCR */
+
+#define IPC_MSG_MAX_SIZE	0x80
+
+
+#define IPC_HEADER_LENGTH_MASK		0x03FF
+#define IPC_HEADER_PROTOCOL_MASK	0x0F
+#define IPC_HEADER_MNG_CMD_MASK		0x0F
+
+#define IPC_HEADER_LENGTH_OFFSET	0
+#define IPC_HEADER_PROTOCOL_OFFSET	10
+#define IPC_HEADER_MNG_CMD_OFFSET	16
+
+#define IPC_HEADER_GET_LENGTH(drbl_reg)		\
+	(((drbl_reg) >> IPC_HEADER_LENGTH_OFFSET)&IPC_HEADER_LENGTH_MASK)
+#define IPC_HEADER_GET_PROTOCOL(drbl_reg)	\
+	(((drbl_reg) >> IPC_HEADER_PROTOCOL_OFFSET)&IPC_HEADER_PROTOCOL_MASK)
+#define IPC_HEADER_GET_MNG_CMD(drbl_reg)	\
+	(((drbl_reg) >> IPC_HEADER_MNG_CMD_OFFSET)&IPC_HEADER_MNG_CMD_MASK)
+
+#define IPC_IS_BUSY(drbl_reg)			\
+	(((drbl_reg)&IPC_DRBL_BUSY_BIT) == ((uint32_t)IPC_DRBL_BUSY_BIT))
+
+/***********************************/
+/*CHV_A0, CHV_B0*/
+#define IPC_INT_FROM_ISH_TO_HOST_CHV_AB(drbl_reg) \
+	(((drbl_reg)&IPC_INT_ISH2HOST_BIT_CHV_AB) == \
+	((u32)IPC_INT_ISH2HOST_BIT_CHV_AB))
+/*BXT, CHV_K0*/
+#define IPC_INT_FROM_ISH_TO_HOST_BXT(drbl_reg) \
+	(((drbl_reg)&IPC_INT_ISH2HOST_BIT_BXT) == \
+	((u32)IPC_INT_ISH2HOST_BIT_BXT))
+/***********************************/
+
+#define IPC_BUILD_HEADER(length, protocol, busy)		\
+	(((busy)<<IPC_DRBL_BUSY_OFFS) |				\
+	((protocol) << IPC_HEADER_PROTOCOL_OFFSET) |		\
+	((length)<<IPC_HEADER_LENGTH_OFFSET))
+
+#define IPC_BUILD_MNG_MSG(cmd, length)				\
+	(((1)<<IPC_DRBL_BUSY_OFFS)|				\
+	((IPC_PROTOCOL_MNG)<<IPC_HEADER_PROTOCOL_OFFSET)|	\
+	((cmd)<<IPC_HEADER_MNG_CMD_OFFSET)|			\
+	 ((length)<<IPC_HEADER_LENGTH_OFFSET))
+
+
+#define IPC_SET_HOST_READY(host_status)		\
+				((host_status) |= (IPC_HOSTCOMM_READY_BIT))
+
+#define IPC_SET_HOST_ILUP(host_status)		\
+				((host_status) |= (IPC_ILUP_BIT))
+
+#define IPC_CLEAR_HOST_READY(host_status)	\
+				((host_status) ^= (IPC_HOSTCOMM_READY_BIT))
+
+#define IPC_CLEAR_HOST_ILUP(host_status)	\
+				((host_status) ^= (IPC_ILUP_BIT))
+
+/* todo - temp until PIMR HW ready */
+#define IPC_HOST_BUSY_READING_OFFS	6
+
+/* bit corresponds host ready bit in Host Status Register (HOST_COMM) */
+#define IPC_HOST_BUSY_READING_BIT	(1<<IPC_HOST_BUSY_READING_OFFS)
+
+#define IPC_SET_HOST_BUSY_READING(host_status)	\
+				((host_status) |= (IPC_HOST_BUSY_READING_BIT))
+
+#define IPC_CLEAR_HOST_BUSY_READING(host_status)\
+				((host_status) ^= (IPC_HOST_BUSY_READING_BIT))
+
+
+#define IPC_IS_ISH_ISHTP_READY(ish_status)	\
+		(((ish_status) & IPC_ISH_ISHTP_READY_BIT) ==	\
+			((uint32_t)IPC_ISH_ISHTP_READY_BIT))
+
+#define IPC_IS_ISH_ILUP(ish_status)		\
+		(((ish_status) & IPC_ILUP_BIT) == ((uint32_t)IPC_ILUP_BIT))
+
+
+#define IPC_PROTOCOL_ISHTP		1
+#define IPC_PROTOCOL_MNG		3
+
+#define MNG_RX_CMPL_ENABLE		0
+#define MNG_RX_CMPL_DISABLE		1
+#define MNG_RX_CMPL_INDICATION		2
+#define MNG_RESET_NOTIFY		3
+#define MNG_RESET_NOTIFY_ACK		4
+#define MNG_SYNC_FW_CLOCK		5
+#define MNG_ILLEGAL_CMD			0xFF
+
+#endif /* _ISHTP_ISH_REGS_H_ */
diff --git a/drivers/hid/intel-ish-hid/ipc/hw-ish.h b/drivers/hid/intel-ish-hid/ipc/hw-ish.h
new file mode 100644
index 0000000..46615a0
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ipc/hw-ish.h
@@ -0,0 +1,71 @@
+/*
+ * H/W layer of ISHTP provider device (ISH)
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef _ISHTP_HW_ISH_H_
+#define _ISHTP_HW_ISH_H_
+
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include "hw-ish-regs.h"
+#include "ishtp-dev.h"
+
+#define CHV_DEVICE_ID		0x22D8
+#define BXT_Ax_DEVICE_ID	0x0AA2
+#define BXT_Bx_DEVICE_ID	0x1AA2
+#define APL_Ax_DEVICE_ID	0x5AA2
+#define SPT_Ax_DEVICE_ID	0x9D35
+
+#define	REVISION_ID_CHT_A0	0x6
+#define	REVISION_ID_CHT_Ax_SI	0x0
+#define	REVISION_ID_CHT_Bx_SI	0x10
+#define	REVISION_ID_CHT_Kx_SI	0x20
+#define	REVISION_ID_CHT_Dx_SI	0x30
+#define	REVISION_ID_CHT_B0	0xB0
+#define	REVISION_ID_SI_MASK	0x70
+
+struct ipc_rst_payload_type {
+	uint16_t	reset_id;
+	uint16_t	reserved;
+};
+
+struct time_sync_format {
+	uint8_t ts1_source;
+	uint8_t ts2_source;
+	uint16_t reserved;
+} __packed;
+
+struct ipc_time_update_msg {
+	uint64_t primary_host_time;
+	struct time_sync_format sync_info;
+	uint64_t secondary_host_time;
+} __packed;
+
+enum {
+	HOST_UTC_TIME_USEC = 0,
+	HOST_SYSTEM_TIME_USEC = 1
+};
+
+struct ish_hw {
+	void __iomem *mem_addr;
+};
+
+#define to_ish_hw(dev) (struct ish_hw *)((dev)->hw)
+
+irqreturn_t ish_irq_handler(int irq, void *dev_id);
+struct ishtp_device *ish_dev_init(struct pci_dev *pdev);
+int ish_hw_start(struct ishtp_device *dev);
+void ish_device_disable(struct ishtp_device *dev);
+
+#endif /* _ISHTP_HW_ISH_H_ */
diff --git a/drivers/hid/intel-ish-hid/ipc/ipc.c b/drivers/hid/intel-ish-hid/ipc/ipc.c
new file mode 100644
index 0000000..851029b
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ipc/ipc.c
@@ -0,0 +1,882 @@
+/*
+ * H/W layer of ISHTP provider device (ISH)
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include "client.h"
+#include "hw-ish.h"
+#include "utils.h"
+#include "hbm.h"
+
+/* For FW reset flow */
+static struct work_struct fw_reset_work;
+static struct ishtp_device *ishtp_dev;
+
+/**
+ * ish_reg_read() - Read register
+ * @dev: ISHTP device pointer
+ * @offset: Register offset
+ *
+ * Read 32 bit register at a given offset
+ *
+ * Return: Read register value
+ */
+static inline uint32_t ish_reg_read(const struct ishtp_device *dev,
+	unsigned long offset)
+{
+	struct ish_hw *hw = to_ish_hw(dev);
+
+	return readl(hw->mem_addr + offset);
+}
+
+/**
+ * ish_reg_write() - Write register
+ * @dev: ISHTP device pointer
+ * @offset: Register offset
+ * @value: Value to write
+ *
+ * Writes 32 bit register at a give offset
+ */
+static inline void ish_reg_write(struct ishtp_device *dev,
+				 unsigned long offset,
+				 uint32_t value)
+{
+	struct ish_hw *hw = to_ish_hw(dev);
+
+	writel(value, hw->mem_addr + offset);
+}
+
+/**
+ * _ish_read_fw_sts_reg() - Read FW status register
+ * @dev: ISHTP device pointer
+ *
+ * Read FW status register
+ *
+ * Return: Read register value
+ */
+static inline uint32_t _ish_read_fw_sts_reg(struct ishtp_device *dev)
+{
+	return ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+}
+
+/**
+ * check_generated_interrupt() - Check if ISH interrupt
+ * @dev: ISHTP device pointer
+ *
+ * Check if an interrupt was generated for ISH
+ *
+ * Return: Read true or false
+ */
+static bool check_generated_interrupt(struct ishtp_device *dev)
+{
+	bool interrupt_generated = true;
+	uint32_t pisr_val = 0;
+
+	if (dev->pdev->device == CHV_DEVICE_ID) {
+		pisr_val = ish_reg_read(dev, IPC_REG_PISR_CHV_AB);
+		interrupt_generated =
+			IPC_INT_FROM_ISH_TO_HOST_CHV_AB(pisr_val);
+	} else {
+		pisr_val = ish_reg_read(dev, IPC_REG_PISR_BXT);
+		interrupt_generated = IPC_INT_FROM_ISH_TO_HOST_BXT(pisr_val);
+	}
+
+	return interrupt_generated;
+}
+
+/**
+ * ish_is_input_ready() - Check if FW ready for RX
+ * @dev: ISHTP device pointer
+ *
+ * Check if ISH FW is ready for receiving data
+ *
+ * Return: Read true or false
+ */
+static bool ish_is_input_ready(struct ishtp_device *dev)
+{
+	uint32_t doorbell_val;
+
+	doorbell_val = ish_reg_read(dev, IPC_REG_HOST2ISH_DRBL);
+	return !IPC_IS_BUSY(doorbell_val);
+}
+
+/**
+ * set_host_ready() - Indicate host ready
+ * @dev: ISHTP device pointer
+ *
+ * Set host ready indication to FW
+ */
+static void set_host_ready(struct ishtp_device *dev)
+{
+	if (dev->pdev->device == CHV_DEVICE_ID) {
+		if (dev->pdev->revision == REVISION_ID_CHT_A0 ||
+				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
+				REVISION_ID_CHT_Ax_SI)
+			ish_reg_write(dev, IPC_REG_HOST_COMM, 0x81);
+		else if (dev->pdev->revision == REVISION_ID_CHT_B0 ||
+				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
+				REVISION_ID_CHT_Bx_SI ||
+				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
+				REVISION_ID_CHT_Kx_SI ||
+				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
+				REVISION_ID_CHT_Dx_SI) {
+			uint32_t host_comm_val;
+
+			host_comm_val = ish_reg_read(dev, IPC_REG_HOST_COMM);
+			host_comm_val |= IPC_HOSTCOMM_INT_EN_BIT_CHV_AB | 0x81;
+			ish_reg_write(dev, IPC_REG_HOST_COMM, host_comm_val);
+		}
+	} else {
+			uint32_t host_pimr_val;
+
+			host_pimr_val = ish_reg_read(dev, IPC_REG_PIMR_BXT);
+			host_pimr_val |= IPC_PIMR_INT_EN_BIT_BXT;
+			/*
+			 * disable interrupt generated instead of
+			 * RX_complete_msg
+			 */
+			host_pimr_val &= ~IPC_HOST2ISH_BUSYCLEAR_MASK_BIT;
+
+			ish_reg_write(dev, IPC_REG_PIMR_BXT, host_pimr_val);
+	}
+}
+
+/**
+ * ishtp_fw_is_ready() - Check if FW ready
+ * @dev: ISHTP device pointer
+ *
+ * Check if ISH FW is ready
+ *
+ * Return: Read true or false
+ */
+static bool ishtp_fw_is_ready(struct ishtp_device *dev)
+{
+	uint32_t ish_status = _ish_read_fw_sts_reg(dev);
+
+	return IPC_IS_ISH_ILUP(ish_status) &&
+		IPC_IS_ISH_ISHTP_READY(ish_status);
+}
+
+/**
+ * ish_set_host_rdy() - Indicate host ready
+ * @dev: ISHTP device pointer
+ *
+ * Set host ready indication to FW
+ */
+static void ish_set_host_rdy(struct ishtp_device *dev)
+{
+	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
+
+	IPC_SET_HOST_READY(host_status);
+	ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
+}
+
+/**
+ * ish_clr_host_rdy() - Indicate host not ready
+ * @dev: ISHTP device pointer
+ *
+ * Send host not ready indication to FW
+ */
+static void ish_clr_host_rdy(struct ishtp_device *dev)
+{
+	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
+
+	IPC_CLEAR_HOST_READY(host_status);
+	ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
+}
+
+/**
+ * _ishtp_read_hdr() - Read message header
+ * @dev: ISHTP device pointer
+ *
+ * Read header of 32bit length
+ *
+ * Return: Read register value
+ */
+static uint32_t _ishtp_read_hdr(const struct ishtp_device *dev)
+{
+	return ish_reg_read(dev, IPC_REG_ISH2HOST_MSG);
+}
+
+/**
+ * _ishtp_read - Read message
+ * @dev: ISHTP device pointer
+ * @buffer: message buffer
+ * @buffer_length: length of message buffer
+ *
+ * Read message from FW
+ *
+ * Return: Always 0
+ */
+static int _ishtp_read(struct ishtp_device *dev, unsigned char *buffer,
+	unsigned long buffer_length)
+{
+	uint32_t	i;
+	uint32_t	*r_buf = (uint32_t *)buffer;
+	uint32_t	msg_offs;
+
+	msg_offs = IPC_REG_ISH2HOST_MSG + sizeof(struct ishtp_msg_hdr);
+	for (i = 0; i < buffer_length; i += sizeof(uint32_t))
+		*r_buf++ = ish_reg_read(dev, msg_offs + i);
+
+	return 0;
+}
+
+/**
+ * write_ipc_from_queue() - try to write ipc msg from Tx queue to device
+ * @dev: ishtp device pointer
+ *
+ * Check if DRBL is cleared. if it is - write the first IPC msg,  then call
+ * the callback function (unless it's NULL)
+ *
+ * Return: 0 for success else failure code
+ */
+static int write_ipc_from_queue(struct ishtp_device *dev)
+{
+	struct wr_msg_ctl_info	*ipc_link;
+	unsigned long	length;
+	unsigned long	rem;
+	unsigned long	flags;
+	uint32_t	doorbell_val;
+	uint32_t	*r_buf;
+	uint32_t	reg_addr;
+	int	i;
+	void	(*ipc_send_compl)(void *);
+	void	*ipc_send_compl_prm;
+	static int	out_ipc_locked;
+	unsigned long	out_ipc_flags;
+
+	if (dev->dev_state == ISHTP_DEV_DISABLED)
+		return	-EINVAL;
+
+	spin_lock_irqsave(&dev->out_ipc_spinlock, out_ipc_flags);
+	if (out_ipc_locked) {
+		spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
+		return -EBUSY;
+	}
+	out_ipc_locked = 1;
+	if (!ish_is_input_ready(dev)) {
+		out_ipc_locked = 0;
+		spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
+		return -EBUSY;
+	}
+	spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
+
+	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
+	/*
+	 * if tx send list is empty - return 0;
+	 * may happen, as RX_COMPLETE handler doesn't check list emptiness.
+	 */
+	if (list_empty(&dev->wr_processing_list_head.link)) {
+		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+		out_ipc_locked = 0;
+		return	0;
+	}
+
+	ipc_link = list_entry(dev->wr_processing_list_head.link.next,
+			      struct wr_msg_ctl_info, link);
+	/* first 4 bytes of the data is the doorbell value (IPC header) */
+	length = ipc_link->length - sizeof(uint32_t);
+	doorbell_val = *(uint32_t *)ipc_link->inline_data;
+	r_buf = (uint32_t *)(ipc_link->inline_data + sizeof(uint32_t));
+
+	/* If sending MNG_SYNC_FW_CLOCK, update clock again */
+	if (IPC_HEADER_GET_PROTOCOL(doorbell_val) == IPC_PROTOCOL_MNG &&
+		IPC_HEADER_GET_MNG_CMD(doorbell_val) == MNG_SYNC_FW_CLOCK) {
+		struct timespec ts_system;
+		struct timeval tv_utc;
+		uint64_t        usec_system, usec_utc;
+		struct ipc_time_update_msg time_update;
+		struct time_sync_format ts_format;
+
+		get_monotonic_boottime(&ts_system);
+		do_gettimeofday(&tv_utc);
+		usec_system = (timespec_to_ns(&ts_system)) / NSEC_PER_USEC;
+		usec_utc = (uint64_t)tv_utc.tv_sec * 1000000 +
+						((uint32_t)tv_utc.tv_usec);
+		ts_format.ts1_source = HOST_SYSTEM_TIME_USEC;
+		ts_format.ts2_source = HOST_UTC_TIME_USEC;
+
+		time_update.primary_host_time = usec_system;
+		time_update.secondary_host_time = usec_utc;
+		time_update.sync_info = ts_format;
+
+		memcpy(r_buf, &time_update,
+		       sizeof(struct ipc_time_update_msg));
+	}
+
+	for (i = 0, reg_addr = IPC_REG_HOST2ISH_MSG; i < length >> 2; i++,
+			reg_addr += 4)
+		ish_reg_write(dev, reg_addr, r_buf[i]);
+
+	rem = length & 0x3;
+	if (rem > 0) {
+		uint32_t reg = 0;
+
+		memcpy(&reg, &r_buf[length >> 2], rem);
+		ish_reg_write(dev, reg_addr, reg);
+	}
+	/* Flush writes to msg registers and doorbell */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	/* Update IPC counters */
+	++dev->ipc_tx_cnt;
+	dev->ipc_tx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
+
+	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, doorbell_val);
+	out_ipc_locked = 0;
+
+	ipc_send_compl = ipc_link->ipc_send_compl;
+	ipc_send_compl_prm = ipc_link->ipc_send_compl_prm;
+	list_del_init(&ipc_link->link);
+	list_add_tail(&ipc_link->link, &dev->wr_free_list_head.link);
+	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+
+	/*
+	 * callback will be called out of spinlock,
+	 * after ipc_link returned to free list
+	 */
+	if (ipc_send_compl)
+		ipc_send_compl(ipc_send_compl_prm);
+
+	return 0;
+}
+
+/**
+ * write_ipc_to_queue() - write ipc msg to Tx queue
+ * @dev: ishtp device instance
+ * @ipc_send_compl: Send complete callback
+ * @ipc_send_compl_prm:	Parameter to send in complete callback
+ * @msg: Pointer to message
+ * @length: Length of message
+ *
+ * Recived msg with IPC (and upper protocol) header  and add it to the device
+ *  Tx-to-write list then try to send the first IPC waiting msg
+ *  (if DRBL is cleared)
+ * This function returns negative value for failure (means free list
+ *  is empty, or msg too long) and 0 for success.
+ *
+ * Return: 0 for success else failure code
+ */
+static int write_ipc_to_queue(struct ishtp_device *dev,
+	void (*ipc_send_compl)(void *), void *ipc_send_compl_prm,
+	unsigned char *msg, int length)
+{
+	struct wr_msg_ctl_info *ipc_link;
+	unsigned long	flags;
+
+	if (length > IPC_FULL_MSG_SIZE)
+		return -EMSGSIZE;
+
+	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
+	if (list_empty(&dev->wr_free_list_head.link)) {
+		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+		return -ENOMEM;
+	}
+	ipc_link = list_entry(dev->wr_free_list_head.link.next,
+		struct wr_msg_ctl_info, link);
+	list_del_init(&ipc_link->link);
+
+	ipc_link->ipc_send_compl = ipc_send_compl;
+	ipc_link->ipc_send_compl_prm = ipc_send_compl_prm;
+	ipc_link->length = length;
+	memcpy(ipc_link->inline_data, msg, length);
+
+	list_add_tail(&ipc_link->link, &dev->wr_processing_list_head.link);
+	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+
+	write_ipc_from_queue(dev);
+
+	return 0;
+}
+
+/**
+ * ipc_send_mng_msg() - Send management message
+ * @dev: ishtp device instance
+ * @msg_code: Message code
+ * @msg: Pointer to message
+ * @size: Length of message
+ *
+ * Send management message to FW
+ *
+ * Return: 0 for success else failure code
+ */
+static int ipc_send_mng_msg(struct ishtp_device *dev, uint32_t msg_code,
+	void *msg, size_t size)
+{
+	unsigned char	ipc_msg[IPC_FULL_MSG_SIZE];
+	uint32_t	drbl_val = IPC_BUILD_MNG_MSG(msg_code, size);
+
+	memcpy(ipc_msg, &drbl_val, sizeof(uint32_t));
+	memcpy(ipc_msg + sizeof(uint32_t), msg, size);
+	return	write_ipc_to_queue(dev, NULL, NULL, ipc_msg,
+		sizeof(uint32_t) + size);
+}
+
+/**
+ * ish_fw_reset_handler() - FW reset handler
+ * @dev: ishtp device pointer
+ *
+ * Handle FW reset
+ *
+ * Return: 0 for success else failure code
+ */
+static int ish_fw_reset_handler(struct ishtp_device *dev)
+{
+	uint32_t	reset_id;
+	unsigned long	flags;
+	struct wr_msg_ctl_info *processing, *next;
+
+	/* Read reset ID */
+	reset_id = ish_reg_read(dev, IPC_REG_ISH2HOST_MSG) & 0xFFFF;
+
+	/* Clear IPC output queue */
+	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
+	list_for_each_entry_safe(processing, next,
+			&dev->wr_processing_list_head.link, link) {
+		list_del(&processing->link);
+		list_add_tail(&processing->link, &dev->wr_free_list_head.link);
+	}
+	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+
+	/* ISHTP notification in IPC_RESET */
+	ishtp_reset_handler(dev);
+
+	if (!ish_is_input_ready(dev))
+		timed_wait_for_timeout(WAIT_FOR_SEND_SLICE,
+			ish_is_input_ready(dev), (2 * HZ));
+
+	/* ISH FW is dead */
+	if (!ish_is_input_ready(dev))
+		return	-EPIPE;
+	/*
+	 * Set HOST2ISH.ILUP. Apparently we need this BEFORE sending
+	 * RESET_NOTIFY_ACK - FW will be checking for it
+	 */
+	ish_set_host_rdy(dev);
+	/* Send RESET_NOTIFY_ACK (with reset_id) */
+	ipc_send_mng_msg(dev, MNG_RESET_NOTIFY_ACK, &reset_id,
+			 sizeof(uint32_t));
+
+	/* Wait for ISH FW'es ILUP and ISHTP_READY */
+	timed_wait_for_timeout(WAIT_FOR_SEND_SLICE, ishtp_fw_is_ready(dev),
+		(2 * HZ));
+	if (!ishtp_fw_is_ready(dev)) {
+		/* ISH FW is dead */
+		uint32_t	ish_status;
+
+		ish_status = _ish_read_fw_sts_reg(dev);
+		dev_err(dev->devc,
+			"[ishtp-ish]: completed reset, ISH is dead (FWSTS = %08X)\n",
+			ish_status);
+		return -ENODEV;
+	}
+	return	0;
+}
+
+/**
+ * ish_fw_reset_work_fn() - FW reset worker function
+ * @unused: not used
+ *
+ * Call ish_fw_reset_handler to complete FW reset
+ */
+static void fw_reset_work_fn(struct work_struct *unused)
+{
+	int	rv;
+
+	rv = ish_fw_reset_handler(ishtp_dev);
+	if (!rv) {
+		/* ISH is ILUP & ISHTP-ready. Restart ISHTP */
+		schedule_timeout(HZ / 3);
+		ishtp_dev->recvd_hw_ready = 1;
+		wake_up_interruptible(&ishtp_dev->wait_hw_ready);
+
+		/* ISHTP notification in IPC_RESET sequence completion */
+		ishtp_reset_compl_handler(ishtp_dev);
+	} else
+		dev_err(ishtp_dev->devc, "[ishtp-ish]: FW reset failed (%d)\n",
+			rv);
+}
+
+/**
+ * _ish_sync_fw_clock() -Sync FW clock with the OS clock
+ * @dev: ishtp device pointer
+ *
+ * Sync FW and OS time
+ */
+static void _ish_sync_fw_clock(struct ishtp_device *dev)
+{
+	static unsigned long	prev_sync;
+	struct timespec	ts;
+	uint64_t	usec;
+
+	if (prev_sync && jiffies - prev_sync < 20 * HZ)
+		return;
+
+	prev_sync = jiffies;
+	get_monotonic_boottime(&ts);
+	usec = (timespec_to_ns(&ts)) / NSEC_PER_USEC;
+	ipc_send_mng_msg(dev, MNG_SYNC_FW_CLOCK, &usec, sizeof(uint64_t));
+}
+
+/**
+ * recv_ipc() - Receive and process IPC management messages
+ * @dev: ishtp device instance
+ * @doorbell_val: doorbell value
+ *
+ * This function runs in ISR context.
+ * NOTE: Any other mng command than reset_notify and reset_notify_ack
+ * won't wake BH handler
+ */
+static void	recv_ipc(struct ishtp_device *dev, uint32_t doorbell_val)
+{
+	uint32_t	mng_cmd;
+
+	mng_cmd = IPC_HEADER_GET_MNG_CMD(doorbell_val);
+
+	switch (mng_cmd) {
+	default:
+		break;
+
+	case MNG_RX_CMPL_INDICATION:
+		if (dev->suspend_flag) {
+			dev->suspend_flag = 0;
+			wake_up_interruptible(&dev->suspend_wait);
+		}
+		if (dev->resume_flag) {
+			dev->resume_flag = 0;
+			wake_up_interruptible(&dev->resume_wait);
+		}
+
+		write_ipc_from_queue(dev);
+		break;
+
+	case MNG_RESET_NOTIFY:
+		if (!ishtp_dev) {
+			ishtp_dev = dev;
+			INIT_WORK(&fw_reset_work, fw_reset_work_fn);
+		}
+		schedule_work(&fw_reset_work);
+		break;
+
+	case MNG_RESET_NOTIFY_ACK:
+		dev->recvd_hw_ready = 1;
+		wake_up_interruptible(&dev->wait_hw_ready);
+		break;
+	}
+}
+
+/**
+ * ish_irq_handler() - ISH IRQ handler
+ * @irq: irq number
+ * @dev_id: ishtp device pointer
+ *
+ * ISH IRQ handler. If interrupt is generated and is for ISH it will process
+ * the interrupt.
+ */
+irqreturn_t ish_irq_handler(int irq, void *dev_id)
+{
+	struct ishtp_device	*dev = dev_id;
+	uint32_t	doorbell_val;
+	bool	interrupt_generated;
+
+	/* Check that it's interrupt from ISH (may be shared) */
+	interrupt_generated = check_generated_interrupt(dev);
+
+	if (!interrupt_generated)
+		return IRQ_NONE;
+
+	doorbell_val = ish_reg_read(dev, IPC_REG_ISH2HOST_DRBL);
+	if (!IPC_IS_BUSY(doorbell_val))
+		return IRQ_HANDLED;
+
+	if (dev->dev_state == ISHTP_DEV_DISABLED)
+		return	IRQ_HANDLED;
+
+	/* Sanity check: IPC dgram length in header */
+	if (IPC_HEADER_GET_LENGTH(doorbell_val) > IPC_PAYLOAD_SIZE) {
+		dev_err(dev->devc,
+			"IPC hdr - bad length: %u; dropped\n",
+			(unsigned int)IPC_HEADER_GET_LENGTH(doorbell_val));
+		goto	eoi;
+	}
+
+	switch (IPC_HEADER_GET_PROTOCOL(doorbell_val)) {
+	default:
+		break;
+	case IPC_PROTOCOL_MNG:
+		recv_ipc(dev, doorbell_val);
+		break;
+	case IPC_PROTOCOL_ISHTP:
+		ishtp_recv(dev);
+		break;
+	}
+
+eoi:
+	/* Update IPC counters */
+	++dev->ipc_rx_cnt;
+	dev->ipc_rx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
+
+	ish_reg_write(dev, IPC_REG_ISH2HOST_DRBL, 0);
+	/* Flush write to doorbell */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	return	IRQ_HANDLED;
+}
+
+/**
+ * _ish_hw_reset() - HW reset
+ * @dev: ishtp device pointer
+ *
+ * Reset ISH HW to recover if any error
+ *
+ * Return: 0 for success else error fault code
+ */
+static int _ish_hw_reset(struct ishtp_device *dev)
+{
+	struct pci_dev *pdev = dev->pdev;
+	int	rv;
+	unsigned int	dma_delay;
+	uint16_t csr;
+
+	if (!pdev)
+		return	-ENODEV;
+
+	rv = pci_reset_function(pdev);
+	if (!rv)
+		dev->dev_state = ISHTP_DEV_RESETTING;
+
+	if (!pdev->pm_cap) {
+		dev_err(&pdev->dev, "Can't reset - no PM caps\n");
+		return	-EINVAL;
+	}
+
+	/* Now trigger reset to FW */
+	ish_reg_write(dev, IPC_REG_ISH_RMP2, 0);
+
+	for (dma_delay = 0; dma_delay < MAX_DMA_DELAY &&
+		_ish_read_fw_sts_reg(dev) & (IPC_ISH_IN_DMA);
+		dma_delay += 5)
+		mdelay(5);
+
+	if (dma_delay >= MAX_DMA_DELAY) {
+		dev_err(&pdev->dev,
+			"Can't reset - stuck with DMA in-progress\n");
+		return	-EBUSY;
+	}
+
+	pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &csr);
+
+	csr &= ~PCI_PM_CTRL_STATE_MASK;
+	csr |= PCI_D3hot;
+	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
+
+	mdelay(pdev->d3_delay);
+
+	csr &= ~PCI_PM_CTRL_STATE_MASK;
+	csr |= PCI_D0;
+	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
+
+	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
+
+	/*
+	 * Send 0 IPC message so that ISH FW wakes up if it was already
+	 * asleep
+	 */
+	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
+
+	/* Flush writes to doorbell and REMAP2 */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	return	0;
+}
+
+/**
+ * _ish_ipc_reset() - IPC reset
+ * @dev: ishtp device pointer
+ *
+ * Resets host and fw IPC and upper layers
+ *
+ * Return: 0 for success else error fault code
+ */
+static int _ish_ipc_reset(struct ishtp_device *dev)
+{
+	struct ipc_rst_payload_type ipc_mng_msg;
+	int	rv = 0;
+
+	ipc_mng_msg.reset_id = 1;
+	ipc_mng_msg.reserved = 0;
+
+	set_host_ready(dev);
+
+	/* Clear the incoming doorbell */
+	ish_reg_write(dev, IPC_REG_ISH2HOST_DRBL, 0);
+	/* Flush write to doorbell */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	dev->recvd_hw_ready = 0;
+
+	/* send message */
+	rv = ipc_send_mng_msg(dev, MNG_RESET_NOTIFY, &ipc_mng_msg,
+		sizeof(struct ipc_rst_payload_type));
+	if (rv) {
+		dev_err(dev->devc, "Failed to send IPC MNG_RESET_NOTIFY\n");
+		return	rv;
+	}
+
+	wait_event_interruptible_timeout(dev->wait_hw_ready,
+					 dev->recvd_hw_ready, 2 * HZ);
+	if (!dev->recvd_hw_ready) {
+		dev_err(dev->devc, "Timed out waiting for HW ready\n");
+		rv = -ENODEV;
+	}
+
+	return rv;
+}
+
+/**
+ * ish_hw_start() -Start ISH HW
+ * @dev: ishtp device pointer
+ *
+ * Set host to ready state and wait for FW reset
+ *
+ * Return: 0 for success else error fault code
+ */
+int ish_hw_start(struct ishtp_device *dev)
+{
+	ish_set_host_rdy(dev);
+	/* After that we can enable ISH DMA operation */
+	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
+
+	/*
+	 * Send 0 IPC message so that ISH FW wakes up if it was already
+	 * asleep
+	 */
+	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
+	/* Flush write to doorbell */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	set_host_ready(dev);
+
+	/* wait for FW-initiated reset flow */
+	if (!dev->recvd_hw_ready)
+		wait_event_interruptible_timeout(dev->wait_hw_ready,
+						 dev->recvd_hw_ready,
+						 10 * HZ);
+
+	if (!dev->recvd_hw_ready) {
+		dev_err(dev->devc,
+			"[ishtp-ish]: Timed out waiting for FW-initiated reset\n");
+		return	-ENODEV;
+	}
+
+	return 0;
+}
+
+/**
+ * ish_ipc_get_header() -Get doorbell value
+ * @dev: ishtp device pointer
+ * @length: length of message
+ * @busy: busy status
+ *
+ * Get door bell value from message header
+ *
+ * Return: door bell value
+ */
+static uint32_t ish_ipc_get_header(struct ishtp_device *dev, int length,
+				   int busy)
+{
+	uint32_t drbl_val;
+
+	drbl_val = IPC_BUILD_HEADER(length, IPC_PROTOCOL_ISHTP, busy);
+
+	return drbl_val;
+}
+
+static const struct ishtp_hw_ops ish_hw_ops = {
+	.hw_reset = _ish_hw_reset,
+	.ipc_reset = _ish_ipc_reset,
+	.ipc_get_header = ish_ipc_get_header,
+	.ishtp_read = _ishtp_read,
+	.write = write_ipc_to_queue,
+	.get_fw_status = _ish_read_fw_sts_reg,
+	.sync_fw_clock = _ish_sync_fw_clock,
+	.ishtp_read_hdr = _ishtp_read_hdr
+};
+
+/**
+ * ish_dev_init() -Initialize ISH devoce
+ * @pdev: PCI device
+ *
+ * Allocate ISHTP device and initialize IPC processing
+ *
+ * Return: ISHTP device instance on success else NULL
+ */
+struct ishtp_device *ish_dev_init(struct pci_dev *pdev)
+{
+	struct ishtp_device *dev;
+	int	i;
+
+	dev = kzalloc(sizeof(struct ishtp_device) + sizeof(struct ish_hw),
+		GFP_KERNEL);
+	if (!dev)
+		return NULL;
+
+	ishtp_device_init(dev);
+
+	init_waitqueue_head(&dev->wait_hw_ready);
+
+	spin_lock_init(&dev->wr_processing_spinlock);
+	spin_lock_init(&dev->out_ipc_spinlock);
+
+	/* Init IPC processing and free lists */
+	INIT_LIST_HEAD(&dev->wr_processing_list_head.link);
+	INIT_LIST_HEAD(&dev->wr_free_list_head.link);
+	for (i = 0; i < IPC_TX_FIFO_SIZE; ++i) {
+		struct wr_msg_ctl_info	*tx_buf;
+
+		tx_buf = kzalloc(sizeof(struct wr_msg_ctl_info), GFP_KERNEL);
+		if (!tx_buf) {
+			/*
+			 * IPC buffers may be limited or not available
+			 * at all - although this shouldn't happen
+			 */
+			dev_err(dev->devc,
+				"[ishtp-ish]: failure in Tx FIFO allocations (%d)\n",
+				i);
+			break;
+		}
+		list_add_tail(&tx_buf->link, &dev->wr_free_list_head.link);
+	}
+
+	dev->ops = &ish_hw_ops;
+	dev->devc = &pdev->dev;
+	dev->mtu = IPC_PAYLOAD_SIZE - sizeof(struct ishtp_msg_hdr);
+	return dev;
+}
+
+/**
+ * ish_device_disable() - Disable ISH device
+ * @dev: ISHTP device pointer
+ *
+ * Disable ISH by clearing host ready to inform firmware.
+ */
+void	ish_device_disable(struct ishtp_device *dev)
+{
+	dev->dev_state = ISHTP_DEV_DISABLED;
+	ish_clr_host_rdy(dev);
+}
diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
new file mode 100644
index 0000000..b14d6f4
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
@@ -0,0 +1,333 @@
+/*
+ * PCI glue for ISHTP provider device (ISH) driver
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/miscdevice.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/intel_ish.h>
+#include "ishtp-dev.h"
+#include "hw-ish.h"
+
+static const struct pci_device_id ish_pci_tbl[] = {
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, CHV_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, BXT_Ax_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, BXT_Bx_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, APL_Ax_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, SPT_Ax_DEVICE_ID)},
+	{0, }
+};
+MODULE_DEVICE_TABLE(pci, ish_pci_tbl);
+
+/**
+ * ish_event_tracer() - Callback function to dump trace messages
+ * @dev:	ishtp device
+ * @format:	printf style format
+ *
+ * Callback to direct log messages to Linux trace buffers
+ */
+static void ish_event_tracer(struct ishtp_device *dev, char *format, ...)
+{
+	if (trace_ishtp_dump_enabled()) {
+		va_list args;
+		char tmp_buf[100];
+
+		va_start(args, format);
+		vsnprintf(tmp_buf, sizeof(tmp_buf), format, args);
+		va_end(args);
+
+		trace_ishtp_dump(tmp_buf);
+	}
+}
+
+/**
+ * ish_init() - Init function
+ * @dev:	ishtp device
+ *
+ * This function initialize wait queues for suspend/resume and call
+ * calls hadware initialization function. This will initiate
+ * startup sequence
+ *
+ * Return: 0 for success or error code for failure
+ */
+static int ish_init(struct ishtp_device *dev)
+{
+	int ret;
+
+	/* Set the state of ISH HW to start */
+	ret = ish_hw_start(dev);
+	if (ret) {
+		dev_err(dev->devc, "ISH: hw start failed.\n");
+		return ret;
+	}
+
+	/* Start the inter process communication to ISH processor */
+	ret = ishtp_start(dev);
+	if (ret) {
+		dev_err(dev->devc, "ISHTP: Protocol init failed.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * ish_probe() - PCI driver probe callback
+ * @pdev:	pci device
+ * @ent:	pci device id
+ *
+ * Initialize PCI function, setup interrupt and call for ISH initialization
+ *
+ * Return: 0 for success or error code for failure
+ */
+static int ish_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	struct ishtp_device *dev;
+	struct ish_hw *hw;
+	int	ret;
+
+	/* enable pci dev */
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: Failed to enable PCI device\n");
+		return ret;
+	}
+
+	/* set PCI host mastering */
+	pci_set_master(pdev);
+
+	/* pci request regions for ISH driver */
+	ret = pci_request_regions(pdev, KBUILD_MODNAME);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: Failed to get PCI regions\n");
+		goto disable_device;
+	}
+
+	/* allocates and initializes the ISH dev structure */
+	dev = ish_dev_init(pdev);
+	if (!dev) {
+		ret = -ENOMEM;
+		goto release_regions;
+	}
+	hw = to_ish_hw(dev);
+	dev->print_log = ish_event_tracer;
+
+	/* mapping IO device memory */
+	hw->mem_addr = pci_iomap(pdev, 0, 0);
+	if (!hw->mem_addr) {
+		dev_err(&pdev->dev, "ISH: mapping I/O range failure\n");
+		ret = -ENOMEM;
+		goto free_device;
+	}
+
+	dev->pdev = pdev;
+
+	pdev->dev_flags |= PCI_DEV_FLAGS_NO_D3;
+
+	/* request and enable interrupt */
+	ret = request_irq(pdev->irq, ish_irq_handler, IRQF_NO_SUSPEND,
+			  KBUILD_MODNAME, dev);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: request IRQ failure (%d)\n",
+			pdev->irq);
+		goto free_device;
+	}
+
+	dev_set_drvdata(dev->devc, dev);
+
+	init_waitqueue_head(&dev->suspend_wait);
+	init_waitqueue_head(&dev->resume_wait);
+
+	ret = ish_init(dev);
+	if (ret)
+		goto free_irq;
+
+	return 0;
+
+free_irq:
+	free_irq(pdev->irq, dev);
+free_device:
+	pci_iounmap(pdev, hw->mem_addr);
+	kfree(dev);
+release_regions:
+	pci_release_regions(pdev);
+disable_device:
+	pci_clear_master(pdev);
+	pci_disable_device(pdev);
+	dev_err(&pdev->dev, "ISH: PCI driver initialization failed.\n");
+
+	return ret;
+}
+
+/**
+ * ish_remove() - PCI driver remove callback
+ * @pdev:	pci device
+ *
+ * This function does cleanup of ISH on pci remove callback
+ */
+static void ish_remove(struct pci_dev *pdev)
+{
+	struct ishtp_device *ishtp_dev = pci_get_drvdata(pdev);
+	struct ish_hw *hw = to_ish_hw(ishtp_dev);
+
+	ishtp_bus_remove_all_clients(ishtp_dev, false);
+	ish_device_disable(ishtp_dev);
+
+	free_irq(pdev->irq, ishtp_dev);
+	pci_iounmap(pdev, hw->mem_addr);
+	pci_release_regions(pdev);
+	pci_clear_master(pdev);
+	pci_disable_device(pdev);
+	kfree(ishtp_dev);
+}
+
+static struct device *ish_resume_device;
+
+/**
+ * ish_resume_handler() - Work function to complete resume
+ * @work:	work struct
+ *
+ * The resume work function to complete resume function asynchronously.
+ * There are two types of platforms, one where ISH is not powered off,
+ * in that case a simple resume message is enough, others we need
+ * a reset sequence.
+ */
+static void ish_resume_handler(struct work_struct *work)
+{
+	struct pci_dev *pdev = to_pci_dev(ish_resume_device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+	int ret;
+
+	ishtp_send_resume(dev);
+
+	/* 50 ms to get resume response */
+	if (dev->resume_flag)
+		ret = wait_event_interruptible_timeout(dev->resume_wait,
+						       !dev->resume_flag,
+						       msecs_to_jiffies(50));
+
+	/*
+	 * If no resume response. This platform  is not S0ix compatible
+	 * So on resume full reboot of ISH processor will happen, so
+	 * need to go through init sequence again
+	 */
+	if (dev->resume_flag)
+		ish_init(dev);
+}
+
+/**
+ * ish_suspend() - ISH suspend callback
+ * @device:	device pointer
+ *
+ * ISH suspend callback
+ *
+ * Return: 0 to the pm core
+ */
+static int ish_suspend(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+
+	enable_irq_wake(pdev->irq);
+	/*
+	 * If previous suspend hasn't been asnwered then ISH is likely dead,
+	 * don't attempt nested notification
+	 */
+	if (dev->suspend_flag)
+		return	0;
+
+	dev->resume_flag = 0;
+	dev->suspend_flag = 1;
+	ishtp_send_suspend(dev);
+
+	/* 25 ms should be enough for live ISH to flush all IPC buf */
+	if (dev->suspend_flag)
+		wait_event_interruptible_timeout(dev->suspend_wait,
+						 !dev->suspend_flag,
+						  msecs_to_jiffies(25));
+
+	return 0;
+}
+
+static DECLARE_WORK(resume_work, ish_resume_handler);
+/**
+ * ish_resume() - ISH resume callback
+ * @device:	device pointer
+ *
+ * ISH resume callback
+ *
+ * Return: 0 to the pm core
+ */
+static int ish_resume(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+
+	ish_resume_device = device;
+	dev->resume_flag = 1;
+
+	disable_irq_wake(pdev->irq);
+	schedule_work(&resume_work);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static const struct dev_pm_ops ish_pm_ops = {
+	.suspend = ish_suspend,
+	.resume = ish_resume,
+};
+#define ISHTP_ISH_PM_OPS	(&ish_pm_ops)
+#else
+#define ISHTP_ISH_PM_OPS	NULL
+#endif
+
+static struct pci_driver ish_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = ish_pci_tbl,
+	.probe = ish_probe,
+	.remove = ish_remove,
+	.driver.pm = ISHTP_ISH_PM_OPS,
+};
+
+static int __init ish_driver_init(void)
+{
+	return pci_register_driver(&ish_driver);
+}
+
+static void __exit ish_driver_exit(void)
+{
+	pci_unregister_driver(&ish_driver);
+}
+
+module_init(ish_driver_init);
+module_exit(ish_driver_exit);
+
+/* Original author */
+MODULE_AUTHOR("Daniel Drubin <daniel.drubin@intel.com>");
+/* Adoption to upstream Linux kernel */
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
+
+MODULE_DESCRIPTION("Intel(R) Integrated Sensor Hub PCI Device Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/intel-ish-hid/ipc/utils.h b/drivers/hid/intel-ish-hid/ipc/utils.h
new file mode 100644
index 0000000..5a82123
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ipc/utils.h
@@ -0,0 +1,64 @@
+/*
+ * Utility macros of ISH
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#ifndef UTILS__H
+#define UTILS__H
+
+#define	WAIT_FOR_SEND_SLICE	(HZ / 10)
+#define	WAIT_FOR_CONNECT_SLICE	(HZ / 10)
+
+/*
+ * Waits for specified event when a thread that triggers event can't signal
+ * Also, waits *at_least* `timeinc` after condition is satisfied
+ */
+#define	timed_wait_for(timeinc, condition)			\
+	do {							\
+		int completed = 0;				\
+		do {						\
+			unsigned long	j;			\
+			int	done = 0;			\
+								\
+			completed = (condition);		\
+			for (j = jiffies, done = 0; !done; ) {	\
+				schedule_timeout(timeinc);	\
+				if (time_is_before_eq_jiffies(j + timeinc)) \
+					done = 1;		\
+			}					\
+		} while (!(completed));				\
+	} while (0)
+
+
+/*
+ * Waits for specified event when a thread that triggers event
+ * can't signal with timeout (use whenever we may hang)
+ */
+#define	timed_wait_for_timeout(timeinc, condition, timeout)	\
+	do {							\
+		int	t = timeout;				\
+		do {						\
+			unsigned long	j;			\
+			int	done = 0;			\
+								\
+			for (j = jiffies, done = 0; !done; ) {	\
+				schedule_timeout(timeinc);	\
+				if (time_is_before_eq_jiffies(j + timeinc)) \
+					done = 1;		\
+			} \
+			t -= timeinc;				\
+			if (t <= 0)				\
+				break;				\
+		} while (!(condition));				\
+	} while (0)
+
+#endif /* UTILS__H */
diff --git a/include/trace/events/intel_ish.h b/include/trace/events/intel_ish.h
new file mode 100644
index 0000000..92f7d5b
--- /dev/null
+++ b/include/trace/events/intel_ish.h
@@ -0,0 +1,30 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM intel_ish
+
+#if !defined(_TRACE_INTEL_ISH_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_INTEL_ISH_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(ishtp_dump,
+
+	TP_PROTO(const char *message),
+
+	TP_ARGS(message),
+
+	TP_STRUCT__entry(
+		__string(message, message)
+	),
+
+	TP_fast_assign(
+		__assign_str(message, message);
+	),
+
+	TP_printk("%s", __get_str(message))
+);
+
+
+#endif /* _TRACE_INTEL_ISH_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
2.7.4

[PATCH v4 5/7] iio: hid-sensors: use asynchronous resume

From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Date: 2016-08-07 09:25:51

Some platforms power off sensor hubs during S3 suspend, which will require
longer time to resume. This hurts system resume time, so resume
asynchronously.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/iio/common/hid-sensors/hid-sensor-trigger.c | 21 ++++++++++++++++++++-
 include/linux/hid-sensor-hub.h                      |  1 +
 2 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
index 5b41f9d..9784ae3 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
@@ -122,6 +122,14 @@ int hid_sensor_power_state(struct hid_sensor_common *st, bool state)
 #endif
 }
 
+static void hid_sensor_set_power_work(struct work_struct *work)
+{
+	struct hid_sensor_common *attrb = container_of(work,
+						       struct hid_sensor_common,
+						       work);
+	_hid_sensor_power_state(attrb, true);
+}
+
 static int hid_sensor_data_rdy_trigger_set_state(struct iio_trigger *trig,
 						bool state)
 {
@@ -170,6 +178,9 @@ int hid_sensor_setup_trigger(struct iio_dev *indio_dev, const char *name,
 		goto error_unreg_trigger;
 
 	iio_device_set_drvdata(indio_dev, attrb);
+
+	INIT_WORK(&attrb->work, hid_sensor_set_power_work);
+
 	pm_suspend_ignore_children(&attrb->pdev->dev, true);
 	pm_runtime_enable(&attrb->pdev->dev);
 	/* Default to 3 seconds, but can be changed from sysfs */
@@ -202,7 +213,15 @@ static int hid_sensor_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 	struct hid_sensor_common *attrb = iio_device_get_drvdata(indio_dev);
+	schedule_work(&attrb->work);
+	return 0;
+}
 
+static int hid_sensor_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct hid_sensor_common *attrb = iio_device_get_drvdata(indio_dev);
 	return _hid_sensor_power_state(attrb, true);
 }
 
@@ -211,7 +230,7 @@ static int hid_sensor_resume(struct device *dev)
 const struct dev_pm_ops hid_sensor_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(hid_sensor_suspend, hid_sensor_resume)
 	SET_RUNTIME_PM_OPS(hid_sensor_suspend,
-			   hid_sensor_resume, NULL)
+			   hid_sensor_runtime_resume, NULL)
 };
 EXPORT_SYMBOL(hid_sensor_pm_ops);
 
diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
index c02b5ce..dd85f35 100644
--- a/include/linux/hid-sensor-hub.h
+++ b/include/linux/hid-sensor-hub.h
@@ -236,6 +236,7 @@ struct hid_sensor_common {
 	struct hid_sensor_hub_attribute_info report_state;
 	struct hid_sensor_hub_attribute_info power_state;
 	struct hid_sensor_hub_attribute_info sensitivity;
+	struct work_struct work;
 };
 
 /* Convert from hid unit expo to regular exponent */
-- 
2.7.4

[PATCH v4 6/7] hid: hid-sensor-hub: Add ISH quirk

From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Date: 2016-08-07 09:25:52

Need enum quirk to change the base of enums to 1 for
power and report descriptors.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/hid/hid-sensor-hub.c | 4 ++++
 1 file changed, 4 insertions(+)
diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
index 3d5ba5b..658a607 100644
--- a/drivers/hid/hid-sensor-hub.c
+++ b/drivers/hid/hid-sensor-hub.c
@@ -16,6 +16,7 @@
  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  *
  */
+
 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/module.h>
@@ -798,6 +799,9 @@ static const struct hid_device_id sensor_hub_devices[] = {
 	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_SENSOR_HUB, USB_VENDOR_ID_ITE,
 			USB_DEVICE_ID_ITE_LENOVO_YOGA900),
 			.driver_data = HID_SENSOR_HUB_ENUM_QUIRK},
+	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_SENSOR_HUB, USB_VENDOR_ID_INTEL_0,
+			0x22D8),
+			.driver_data = HID_SENSOR_HUB_ENUM_QUIRK},
 	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_SENSOR_HUB, HID_ANY_ID,
 		     HID_ANY_ID) },
 	{ }
-- 
2.7.4

Re: [PATCH v4 5/7] iio: hid-sensors: use asynchronous resume

From: Jiri Kosina <jikos@kernel.org>
Date: 2016-08-07 10:15:50

On Sun, 7 Aug 2016, Srinivas Pandruvada wrote:
Some platforms power off sensor hubs during S3 suspend, which will require
longer time to resume. This hurts system resume time, so resume
asynchronously.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Jonathan, are you going to cherry-pick this patch from the series? 
Alternatively, if you're okay with it, I can pull it in together with the 
whole set with your Acked-by or Reviewed-by.

Thanks,

-- 
Jiri Kosina
SUSE Labs
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