Add support for Qualcomm Snapdragon SA8775P SoC to the EPF driver.
SA8775P is currently reusing the PID 0x0306 (the default one hardcoded
in the config space header) as the unique PID is not yet allocated.
But the host side stack works fine with the default PID. It will get
updated once the PID is finalized. Also, it has no fixed PCI class as of
now, so it is being advertised as "PCI_CLASS_OTHERS".
Signed-off-by: Mrinmay Sarkar <quic_msarkar@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1701432377-16899-5-git-send-email-quic_msarkar@quicinc.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Without the prefix, the function name would appear as
"/sys/kernel/config/functions/{sdx55/sm8450}". This will be a problem if
multiple functions are supported for this endpoint device.
So let's add the "pci_epf_mhi_" prefix to identify _this_ function
uniquely. Even though it is an ABI breakage, this driver is not used
anywhere outside Qcom and myself to my knowledge. So it safe to change
the function name.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Mrinmay Sarkar <quic_msarkar@quicinc.com>
Link: https://lore.kernel.org/r/1701432377-16899-4-git-send-email-quic_msarkar@quicinc.com
Pull char/misc and other driver updates from Greg KH:
"Here is the big set of char/misc and other driver subsystem changes
for 6.8-rc1.
Other than lots of binder driver changes (as you can see by the merge
conflicts) included in here are:
- lots of iio driver updates and additions
- spmi driver updates
- eeprom driver updates
- firmware driver updates
- ocxl driver updates
- mhi driver updates
- w1 driver updates
- nvmem driver updates
- coresight driver updates
- platform driver remove callback api changes
- tags.sh script updates
- bus_type constant marking cleanups
- lots of other small driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (341 commits)
android: removed duplicate linux/errno
uio: Fix use-after-free in uio_open
drivers: soc: xilinx: add check for platform
firmware: xilinx: Export function to use in other module
scripts/tags.sh: remove find_sources
scripts/tags.sh: use -n to test archinclude
scripts/tags.sh: add local annotation
scripts/tags.sh: use more portable -path instead of -wholename
scripts/tags.sh: Update comment (addition of gtags)
firmware: zynqmp: Convert to platform remove callback returning void
firmware: turris-mox-rwtm: Convert to platform remove callback returning void
firmware: stratix10-svc: Convert to platform remove callback returning void
firmware: stratix10-rsu: Convert to platform remove callback returning void
firmware: raspberrypi: Convert to platform remove callback returning void
firmware: qemu_fw_cfg: Convert to platform remove callback returning void
firmware: mtk-adsp-ipc: Convert to platform remove callback returning void
firmware: imx-dsp: Convert to platform remove callback returning void
firmware: coreboot_table: Convert to platform remove callback returning void
firmware: arm_scpi: Convert to platform remove callback returning void
firmware: arm_scmi: Convert to platform remove callback returning void
...
Now that both eDMA and iATU are prepared to support async transfer, let's
enable MHI async read/write by supplying the relevant callbacks.
In the absence of eDMA, iATU will be used for both sync and async
operations.
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
The driver currently supports only the sync read/write operation i.e., it
waits for the DMA transfer to complete before returning to the caller
(MHI stack). But it is sub-optimal and defeats the actual purpose of using
DMA.
So let's add support for DMA async read/write operation by skipping the DMA
transfer completion and returning to the caller immediately. When the
completion actually happens later, the driver will be notified using the
DMA completion handler and in turn it will notify the caller using the
newly introduced callback in "struct mhi_ep_buf_info".
Since the DMA completion handler is invoked from the interrupt context, a
separate workqueue (epf_mhi->dma_wq) is used to notify the caller about the
completion of the transfer.
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Even though iATU only supports synchronous read/write, the MHI stack may
call async read/write callbacks without knowing the limitations of the
controller driver. So in order to maintain compatibility, let's simulate
async read/write operation with iATU by invoking the completion callback
after memcpy.
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
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>
For transfers below 4K, let's use iATU since using eDMA for such small
transfers is inefficient.
This is mainly because setting up an eDMA transfer and waiting for
completion adds some latency. This latency is negligible for large
transfers but not for the smaller ones.
With using iATU, there is an increase in ~50Mbps throughput on both MHI
UL (Uplink) and DL (Downlink) channels.
[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20230717065459.14138-7-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Add support for Embedded DMA (eDMA) available in the DesignWare PCIe IP
to transfer the MHI buffers between the host and the endpoint. The eDMA
use helps achieve greater throughput as the transfers are offloaded from
CPUs.
For differentiating the iATU and eDMA APIs, the pci_epf_mhi_{read/write}
APIs are renamed to pci_epf_mhi_iatu_{read/write} and separate eDMA
specific APIs pci_epf_mhi_edma_{read/write} are introduced.
Platforms that require eDMA support can pass the MHI_EPF_USE_DMA flag
through pci_epf_mhi_ep_info.
[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20230717065459.14138-5-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
