In the preparation for adding async API support, let's rename the existing
APIs to read_sync() and write_sync() to make it explicit that these APIs
are used for synchronous read/write.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
In the preparation of DMA async support, let's pass the parameters to
read_from_host() and write_to_host() APIs using mhi_ep_buf_info structure.
No functional change.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
MHI spec defines the interrupt moderation timer feature using which the
host can limit the number of interrupts being raised for an event ring by
the device. This feature allows the host to process multiple event ring
elements by a single IRQ from the device, thereby eliminating the need to
process IRQ for each element.
The INTMODT field in the event context array provides the value to be used
for delaying the IRQ generation from device. This value, along with the
Block Event Interrupt (BEI) flag of the TRE defines how IRQ is generated to
the host.
Support for interrupt moderation timer is implemented using delayed
workqueue in kernel. And a separate delayed work item is used for each
event ring.
Link: https://lore.kernel.org/r/20231026045513.12981-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Add support for managing the MHI ring. The MHI ring is a circular queue
of data structures used to pass the information between host and the
endpoint.
MHI support 3 types of rings:
1. Transfer ring
2. Event ring
3. Command ring
All rings reside inside the host memory and the MHI EP device maps it to
the device memory using blocks like PCIe iATU. The mapping is handled in
the MHI EP controller driver itself.
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220405135754.6622-6-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Manivannan Sadhasivam