Hi Greg, On Wed, Jan 13, 2021 at 08:56:25PM +0530, Manivannan Sadhasivam wrote: > Hi Greg, > > On Wed, Jan 06, 2021 at 10:44:13AM -0800, Hemant Kumar wrote: > > This patch series adds support for UCI driver. UCI driver enables userspace > > clients to communicate to external MHI devices like modem. UCI driver probe > > creates standard character device file nodes for userspace clients to > > perform open, read, write, poll and release file operations. These file > > operations call MHI core layer APIs to perform data transfer using MHI bus > > to communicate with MHI device. > > > > This interface allows exposing modem control channel(s) such as QMI, MBIM, > > or AT commands to userspace which can be used to configure the modem using > > tools such as libqmi, ModemManager, minicom (for AT), etc over MHI. This is > > required as there are no kernel APIs to access modem control path for device > > configuration. Data path transporting the network payload (IP), however, is > > routed to the Linux network via the mhi-net driver. Currently driver supports > > QMI channel. libqmi is userspace MHI client which communicates to a QMI > > service using QMI channel. Please refer to > > https://www.freedesktop.org/wiki/Software/libqmi/ for additional information > > on libqmi. > > > > Patch is tested using arm64 and x86 based platform. > > > > This series looks good to me and I'd like to merge it into mhi-next. You > shared your reviews on the previous revisions, so I'd like to get your > opinion first. > Ping! Thanks, Mani > Thanks, > Mani > > > V18: > > - Updated commit text for UCI to clarify why this driver is required for QMI > > over MHI. Also updated cover letter with same information. > > > > v17: > > - Updated commit text for UCI driver by mentioning about libqmi open-source > > userspace program that will be talking to this UCI kernel driver. > > - UCI driver depends upon patch "bus: mhi: core: Add helper API to return number > > of free TREs". > > > > v16: > > - Removed reference of WLAN as an external MHI device in documentation and > > cover letter. > > > > v15: > > - Updated documentation related to poll and release operations. > > > > V14: > > - Fixed device file node format to /dev/<mhi_dev_name> instead of > > /dev/mhi_<mhi_dev_name> because "mhi" is already part of mhi device name. > > For example old format: /dev/mhi_mhi0_QMI new format: /dev/mhi0_QMI. > > - Updated MHI documentation to reflect index mhi controller name in > > QMI usage example. > > > > V13: > > - Removed LOOPBACK channel from mhi_device_id table from this patch series. > > Pushing a new patch series to add support for LOOPBACK channel and the user > > space test application. Also removed the description from kernel documentation. > > - Added QMI channel to mhi_device_id table. QMI channel has existing libqmi > > support from user space. > > - Updated kernel Documentation for QMI channel and provided external reference > > for libqmi. > > - Updated device file node name by appending mhi device name only, which already > > includes mhi controller device name. > > > > V12: > > - Added loopback test driver under selftest/drivers/mhi. Updated kernel > > documentation for the usage of the loopback test application. > > - Addressed review comments for renaming variable names, updated inline > > comments and removed two redundant dev_dbg. > > > > V11: > > - Fixed review comments for UCI documentation by expanding TLAs and rewording > > some sentences. > > > > V10: > > - Replaced mutex_lock with mutex_lock_interruptible in read() and write() file > > ops call back. > > > > V9: > > - Renamed dl_lock to dl_pending _lock and pending list to dl_pending for > > clarity. > > - Used read lock to protect cur_buf. > > - Change transfer status check logic and only consider 0 and -EOVERFLOW as > > only success. > > - Added __int to module init function. > > - Print channel name instead of minor number upon successful probe. > > > > V8: > > - Fixed kernel test robot compilation error by changing %lu to %zu for > > size_t. > > - Replaced uci with UCI in Kconfig, commit text, and comments in driver > > code. > > - Fixed minor style related comments. > > > > V7: > > - Decoupled uci device and uci channel objects. uci device is > > associated with device file node. uci channel is associated > > with MHI channels. uci device refers to uci channel to perform > > MHI channel operations for device file operations like read() > > and write(). uci device increments its reference count for > > every open(). uci device calls mhi_uci_dev_start_chan() to start > > the MHI channel. uci channel object is tracking number of times > > MHI channel is referred. This allows to keep the MHI channel in > > start state until last release() is called. After that uci channel > > reference count goes to 0 and uci channel clean up is performed > > which stops the MHI channel. After the last call to release() if > > driver is removed uci reference count becomes 0 and uci object is > > cleaned up. > > - Use separate uci channel read and write lock to fine grain locking > > between reader and writer. > > - Use uci device lock to synchronize open, release and driver remove. > > - Optimize for downlink only or uplink only UCI device. > > > > V6: > > - Moved uci.c to mhi directory. > > - Updated Kconfig to add module information. > > - Updated Makefile to rename uci object file name as mhi_uci > > - Removed kref for open count > > > > V5: > > - Removed mhi_uci_drv structure. > > - Used idr instead of creating global list of uci devices. > > - Used kref instead of local ref counting for uci device and > > open count. > > - Removed unlikely macro. > > > > V4: > > - Fix locking to protect proper struct members. > > - Updated documentation describing uci client driver use cases. > > - Fixed uci ref counting in mhi_uci_open for error case. > > - Addressed style related review comments. > > > > V3: Added documentation for MHI UCI driver. > > > > V2: > > - Added mutex lock to prevent multiple readers to access same > > - mhi buffer which can result into use after free. > > > > Hemant Kumar (3): > > bus: mhi: core: Move MHI_MAX_MTU to external header file > > docs: Add documentation for userspace client interface > > bus: mhi: Add userspace client interface driver > > > > Documentation/mhi/index.rst | 1 + > > Documentation/mhi/uci.rst | 95 ++++++ > > drivers/bus/mhi/Kconfig | 13 + > > drivers/bus/mhi/Makefile | 3 + > > drivers/bus/mhi/core/internal.h | 1 - > > drivers/bus/mhi/uci.c | 664 ++++++++++++++++++++++++++++++++++++++++ > > include/linux/mhi.h | 3 + > > 7 files changed, 779 insertions(+), 1 deletion(-) > > create mode 100644 Documentation/mhi/uci.rst > > create mode 100644 drivers/bus/mhi/uci.c > > > > -- > > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > > a Linux Foundation Collaborative Project > >
