Manivannan writes:
MHI changes for v5.19
MHI Host
--------
Support for new modems:
- Foxconn Cinterion MV32-WA/MV32-WB based on SDX62/SDX65
- Telit FN980 v1 based on SDX55
- Telit FN990 based on SDX65
- Foxconn T99W373/T99W368 based on SDX62/SDX65
Core changes:
- During the recycle of event ring elements, compute the ctxt_wp based on the
local cached value instead of reading from shared memory. This is to prevent
the possible corruption of the ctxt_wp as some of the endpoint devices could
modify the value in shared memory.
- Add sysfs support for resetting the endpoint based on the MHI spec. The MHI
spec allows the host to hard reset the device in the case of an unrecoverable
error and all other reset mechanisms have failed.
- During MHI shutdown, wait for the endpoint device to enter the ready state
post reset before proceeding. This is to avoid a possible race where host
would remove the interrupt handler and device will send ready state
interrupt, resulting in IOMMU fault.
- Bail out updating the MHI register if the read has failed during
read/modify/write.
- Use mhi_write_reg() instead of mhi_write_reg_field() for writing the whole
register fields in mhi_init_mmio().
MAINTAINERS change:
- Since Qualcomm has moved the email domain for its employess from codeaurora
domain to quicinc, update the same for Hemant.
* tag 'mhi-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi: (29 commits)
bus: mhi: host: Add support for Foxconn T99W373 and T99W368
bus: mhi: host: pci_generic: add Telit FN990
bus: mhi: host: pci_generic: add Telit FN980 v1 hardware revision
bus: mhi: host: Add support for Cinterion MV32-WA/MV32-WB
bus: mhi: host: Optimize and update MMIO register write method
bus: mhi: host: Bail on writing register fields if read fails
bus: mhi: host: Wait for ready state after reset
bus: mhi: host: Add soc_reset sysfs
bus: mhi: host: pci_generic: Sort mhi_pci_id_table based on the PID
bus: mhi: host: Use cached values for calculating the shared write pointer
MAINTAINERS: Update Hemant's email id
bus: mhi: ep: Add uevent support for module autoloading
bus: mhi: ep: Add support for suspending and resuming channels
bus: mhi: ep: Add support for queueing SKBs to the host
bus: mhi: ep: Add support for processing channel rings
bus: mhi: ep: Add support for reading from the host
bus: mhi: ep: Add support for processing command rings
bus: mhi: ep: Add support for handling SYS_ERR condition
bus: mhi: ep: Add support for handling MHI_RESET
bus: mhi: ep: Add support for powering down the MHI endpoint stack
...
The MHI bus supports a standardized hardware reset, which is known as the
"SoC Reset". This reset is similar to the reset sysfs for PCI devices -
a hardware mechanism to reset the state back to square one.
The MHI SoC Reset is described in the spec as a reset of last resort. If
some unrecoverable error has occurred where other resets have failed, SoC
Reset is the "big hammer" that ungracefully resets the device. This is
effectivly the same as yanking the power on the device, and reapplying it.
However, depending on the nature of the particular issue, the underlying
transport link may remain active and configured. If the link remains up,
the device will flag a MHI system error early in the boot process after
the reset is executed, which allows the MHI bus to process a fatal error
event, and clean up appropiately.
While the SoC Reset is generally intended as a means of recovery when all
else has failed, it can be useful in non-error scenarios. For example,
if the device loads firmware from the host filesystem, the device may need
to be fully rebooted inorder to pick up the new firmware. In this
scenario, the system administrator may use the soc_reset sysfs to cause
the device to pick up the new firmware that the admin placed on the
filesystem.
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Bhaumik Bhatt <quic_bbhatt@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1650302327-30439-1-git-send-email-quic_jhugo@quicinc.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Functions like mhi_read_reg_field(), mhi_poll_reg_field() and
mhi_write_reg_field() could be modified to not depend on the shift value
passed as an argument. Instead, the bitfield operation could be used to
extract the shift value from the mask itself.
This eliminates the need to define _SHIFT (and _SHFT) macros and
simplifies the code a bit. For shift values those cannot be determined
during build time, "__ffs()" helper is used find the shift value during
runtime.
While at it, let's also get rid of 32-bit masks like CHDBOFF_CHDBOFF_MASK
by doing the full 32-bit register read.
Suggested-by: Alex Elder <elder@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220301160308.107452-6-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
