[PATCH v7 0/2] mmc: sdhci-of-dwcmshc: Add CQE support

From: Sergey Khimich
Date: Tue Mar 19 2024 - 07:59:46 EST


Hello!

This is implementation of SDHCI CQE support for sdhci-of-dwcmshc driver.
For enabling CQE support just set 'supports-cqe' in your DevTree file
for appropriate mmc node.

Also, while implementing CQE support for the driver, I faced with a problem
which I will describe below.
According to the IP block documentation CQE works only with "AMDA-2 only"
mode which is activated only with v4 mode enabled. I see in dwcmshc_probe()
function that v4 mode gets enabled only for 'sdhci_dwcmshc_bf3_pdata'
platform data.

So my question is: is it correct to enable v4 mode for all platform data
if 'SDHCI_CAN_64BIT_V4' bit is set in hw?

Because I`m afraid that enabling v4 mode for some platforms could break
them down. On the other hand, if host controller says that it can do v4
(caps & SDHCI_CAN_64BIT_V4), lets do v4 or disable it manualy by some
quirk. Anyway - RFC.


v2:
- Added dwcmshc specific cqe_disable hook to prevent losing
in-flight cmd when an ioctl is issued and cqe_disable is called;

- Added processing 128Mb boundary for the host memory data buffer size
and the data buffer. For implementing this processing an extra
callback is added to the struct 'sdhci_ops'.

- Fixed typo.

v3:
- Fix warning reported by kernel test robot:
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309270807.VoVn81m6-lkp@xxxxxxxxx/
| Closes: https://lore.kernel.org/oe-kbuild-all/202309300806.dcR19kcE-lkp@xxxxxxxxx/

v4:
- Data reset moved to custom driver tuning hook.
- Removed unnecessary dwcmshc_sdhci_cqe_disable() func
- Removed unnecessary dwcmshc_cqhci_set_tran_desc. Export and use
cqhci_set_tran_desc() instead.
- Provide a hook for cqhci_set_tran_desc() instead of cqhci_prep_tran_desc().
- Fix typo: int_clok_disable --> int_clock_disable

v5:
- Fix warning reported by kernel test robot:
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312301130.itEZhhI5-lkp@xxxxxxxxx/

v6:
- Rebase to master branch
- Fix typo;
- Fix double blank line;
- Add cqhci_suspend() and cqhci_resume() functions
to support mmc suspend-to-ram (s2r);
- Move reading DWCMSHC_P_VENDOR_AREA2 register under "supports-cqe"
condition as not all IPs have that register;
- Remove sdhci V4 mode from the list of prerequisites to init cqhci.

v7:
- Add disabling MMC_CAP2_CQE and MMC_CAP2_CQE_DCMD caps
in case of CQE init fails to prevent problems in suspend/resume
functions.

Sergey Khimich (2):
mmc: cqhci: Add cqhci set_tran_desc() callback
mmc: sdhci-of-dwcmshc: Implement SDHCI CQE support

drivers/mmc/host/Kconfig | 1 +
drivers/mmc/host/cqhci-core.c | 11 +-
drivers/mmc/host/cqhci.h | 4 +
drivers/mmc/host/sdhci-of-dwcmshc.c | 191 +++++++++++++++++++++++++++-
4 files changed, 202 insertions(+), 5 deletions(-)

--
2.30.2