linux/Documentation/ABI/testing/sysfs-platform-hidma-mgmt
Sinan Kaya 7f8f209fd6 dmaengine: add Qualcomm Technologies HIDMA management driver
The Qualcomm Technologies HIDMA device has been designed to support
virtualization technology. The driver has been divided into two to follow
the hardware design.

1. HIDMA Management driver
2. HIDMA Channel driver

Each HIDMA HW consists of multiple channels. These channels share some set
of common parameters. These parameters are initialized by the management
driver during power up. Same management driver is used for monitoring the
execution of the channels. Management driver can change the performance
behavior dynamically such as bandwidth allocation and prioritization.

The management driver is executed in host context and is the main
management entity for all channels provided by the device.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-03-11 07:42:23 +05:30

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What: /sys/devices/platform/hidma-mgmt*/chanops/chan*/priority
/sys/devices/platform/QCOM8060:*/chanops/chan*/priority
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Contains either 0 or 1 and indicates if the DMA channel is a
low priority (0) or high priority (1) channel.
What: /sys/devices/platform/hidma-mgmt*/chanops/chan*/weight
/sys/devices/platform/QCOM8060:*/chanops/chan*/weight
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Contains 0..15 and indicates the weight of the channel among
equal priority channels during round robin scheduling.
What: /sys/devices/platform/hidma-mgmt*/chreset_timeout_cycles
/sys/devices/platform/QCOM8060:*/chreset_timeout_cycles
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Contains the platform specific cycle value to wait after a
reset command is issued. If the value is chosen too short,
then the HW will issue a reset failure interrupt. The value
is platform specific and should not be changed without
consultance.
What: /sys/devices/platform/hidma-mgmt*/dma_channels
/sys/devices/platform/QCOM8060:*/dma_channels
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Contains the number of dma channels supported by one instance
of HIDMA hardware. The value may change from chip to chip.
What: /sys/devices/platform/hidma-mgmt*/hw_version_major
/sys/devices/platform/QCOM8060:*/hw_version_major
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Version number major for the hardware.
What: /sys/devices/platform/hidma-mgmt*/hw_version_minor
/sys/devices/platform/QCOM8060:*/hw_version_minor
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Version number minor for the hardware.
What: /sys/devices/platform/hidma-mgmt*/max_rd_xactions
/sys/devices/platform/QCOM8060:*/max_rd_xactions
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Contains a value between 0 and 31. Maximum number of
read transactions that can be issued back to back.
Choosing a higher number gives better performance but
can also cause performance reduction to other peripherals
sharing the same bus.
What: /sys/devices/platform/hidma-mgmt*/max_read_request
/sys/devices/platform/QCOM8060:*/max_read_request
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Size of each read request. The value needs to be a power
of two and can be between 128 and 1024.
What: /sys/devices/platform/hidma-mgmt*/max_wr_xactions
/sys/devices/platform/QCOM8060:*/max_wr_xactions
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Contains a value between 0 and 31. Maximum number of
write transactions that can be issued back to back.
Choosing a higher number gives better performance but
can also cause performance reduction to other peripherals
sharing the same bus.
What: /sys/devices/platform/hidma-mgmt*/max_write_request
/sys/devices/platform/QCOM8060:*/max_write_request
Date: Nov 2015
KernelVersion: 4.4
Contact: "Sinan Kaya <okaya@cudeaurora.org>"
Description:
Size of each write request. The value needs to be a power
of two and can be between 128 and 1024.