scsi: ufs: cdns-pltfrm: Perform read back after writing HCLKDIV

Currently, HCLKDIV is written to and then completed with an mb().

mb() ensures that the write completes, but completion doesn't mean

scsi: ufs: cdns-pltfrm: Perform read back after writing HCLKDIV

Currently, HCLKDIV is written to and then completed with an mb().

mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring this
bit has taken effect on the device is to perform a read back to force it to
make it all the way to the device. This is documented in device-io.rst and
a talk by Will Deacon on this can be seen over here:

https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

Let's do that to ensure the bit hits the device. Because the mb()'s purpose
wasn't to add extra ordering (on top of the ordering guaranteed by
writel()/readl()), it can safely be removed.

Fixes: d90996dae8e4 ("scsi: ufs: Add UFS platform driver for Cadence UFS")
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-6-181252004586@redhat.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: ufs: Convert all platform drivers to return void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling b

scsi: ufs: Convert all platform drivers to return void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart from
emitting a warning) and this typically results in resource leaks. To
improve here there is a quest to make the remove callback return void. In
the first step of this quest all drivers are converted to .remove_new()
which already returns void. Eventually after all drivers are converted,
.remove_new() is renamed to .remove().

All platform drivers below drivers/ufs/ unconditionally return zero in
their remove callback and so can be converted trivially to the variant
returning void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230917145722.1131557-1-u.kleine-koenig@pengutronix.de
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: ufs: Fix kernel-doc headers

Fix the remaining kernel-doc warnings that are reported when building with
W=2.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r

scsi: ufs: Fix kernel-doc headers

Fix the remaining kernel-doc warnings that are reported when building with
W=2.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230727194457.3152309-4-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: ufs: Document all return values

This patch fixes multiple W=2 kernel-doc warnings.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230727194457.3152309-3

scsi: ufs: Document all return values

This patch fixes multiple W=2 kernel-doc warnings.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230727194457.3152309-3-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: ufs: Follow the kernel-doc syntax for documenting return values

Use 'Return:' to document the return value instead of 'Returns' as required
by the kernel-doc documentation.

Signed-off-by: Bar

scsi: ufs: Follow the kernel-doc syntax for documenting return values

Use 'Return:' to document the return value instead of 'Returns' as required
by the kernel-doc documentation.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230727194457.3152309-2-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: ufs: core: Simplify driver shutdown

All UFS host drivers call ufshcd_shutdown(). Hence, instead of calling
ufshcd_shutdown() from the host driver .shutdown() callback, inline that
function int

scsi: ufs: core: Simplify driver shutdown

All UFS host drivers call ufshcd_shutdown(). Hence, instead of calling
ufshcd_shutdown() from the host driver .shutdown() callback, inline that
function into ufshcd_wl_shutdown().

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230524203659.1394307-5-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: ufs: Split the drivers/scsi/ufs directory

Split the drivers/scsi/ufs directory into 'core' and 'host' directories
under the drivers/ufs/ directory. Move shared header files into the
include/uf

scsi: ufs: Split the drivers/scsi/ufs directory

Split the drivers/scsi/ufs directory into 'core' and 'host' directories
under the drivers/ufs/ directory. Move shared header files into the
include/ufs/ directory. This separation makes it clear which header files
UFS drivers are allowed to include (include/ufs/*.h) and which header files
UFS drivers are not allowed to include (drivers/ufs/core/*.h).

Update the MAINTAINERS file. Add myself as a UFS reviewer.

Link: https://lore.kernel.org/r/20220511212552.655341-1-bvanassche@acm.org
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Avri Altman <avri.altman@wdc.com>
Cc: Bean Huo <beanhuo@micron.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Keoseong Park <keosung.park@samsung.com>
Tested-by: Bean Huo <beanhuo@micron.com>
Tested-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Acked-by: Avri Altman <avri.altman@wdc.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...