[PATCH v3 0/5] Add missing reset controls to NVIDIA Tegra ASoC drivers

Dmitry Osipenko
2021-03-11T17:44:07Z

Hi,

This series adds missing hardware reset controls to I2S and AC97 drivers.
Currently drivers happen to work properly because reset is implicitly
deasserted by tegra-clk driver, but clk driver shouldn't touch the resets
and we need to fix it because this breaks other Tegra drivers. Previously
we fixed the resets of the AHUB and HDMI codec drivers, but turned out
that we missed the I2C and AC97 drivers.

Thanks to Paul Fertser for testing the pending clk patches and finding
that audio got broken on Tegra20 AC100 netbook because of the missing I2S
reset.

Changelog:

v3: - Fixed reset stubs for !CONFIG_RESET_CONTROLLER.

v2: - After some more testing I found that I2S control logic doesn't require
I2S clock to be enabled for resetting. Hence it's fine to have I2S to
be reset by parent AHUB driver, so I dropped "tegra30: i2s: Add reset
control" patch.

- While I was double-checking resets on Tegra30, I found that that
Tegra30 I2S driver has a broken runtime PM which doesn't restore
hardware state on resume and it's lost after AHUB RPM-resume.
Thus, added this new patch "tegra30: i2s: Restore hardware state
on runtime PM resume".

- Added new patches which switch AHUB driver to use reset-bulk API.
I took the RFC patch from Philipp Zabel, fixed it and added
devm_reset_control_bulk_optional_get_exclusive_released() that
will be useful for further Tegra GPU patches. This is a minor
improvement which makes code cleaner.

Dmitry Osipenko (4):
ASoC: tegra20: ac97: Add reset control
ASoC: tegra20: i2s: Add reset control
ASoC: tegra30: i2s: Restore hardware state on runtime PM resume
ASoC: tegra: ahub: Switch to use reset-bulk API

Philipp Zabel (1):
reset: Add reset_control_bulk API

drivers/reset/core.c | 215 +++++++++++++++++++++++
include/linux/reset.h | 308 +++++++++++++++++++++++++++++++++
sound/soc/tegra/tegra20_ac97.c | 21 +++
sound/soc/tegra/tegra20_ac97.h | 1 +
sound/soc/tegra/tegra20_i2s.c | 31 ++++
sound/soc/tegra/tegra20_i2s.h | 1 +
sound/soc/tegra/tegra30_ahub.c | 104 ++++-------
sound/soc/tegra/tegra30_ahub.h | 5 +-
sound/soc/tegra/tegra30_i2s.c | 41 ++---
9 files changed, 629 insertions(+), 98 deletions(-)

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2.29.2