[ Upstream commit ab344fd43f2958726d17d651c0cb692c67dca382 ]
When the DVFSRC (dynamic voltage and frequency scaling resource collector)
feature is not implemented, the PCIe hardware will assert a voltage request
signal when exit from the L1 PM Substates to request a specific Vcore
voltage, but cannot receive the voltage ready signal, which will cause
the link to fail to exit the L1 PM Substates.
Disable DVFSRC voltage request by default, we need to find a common way to
enable it in the future.
Link: https://lore.kernel.org/r/20211015063602.29058-1-jianjun.wang@mediatek.com
Fixes: d3bf75b579 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver for MT8192")
Tested-by: Qizhong Cheng <qizhong.cheng@mediatek.com>
Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Tzung-Bi Shih <tzungbi@google.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Add suspend_noirq and resume_noirq callback functions to implement PM
system suspend and resume hooks for the MediaTek Gen3 PCIe controller.
When the system suspends, trigger the PCIe link to enter the L2 state
and pull down the PERST# pin, gating the clocks of the MAC layer, and
then power-off the physical layer to provide power-saving.
When the system resumes, the PCIe link should be re-established and the
related control register values should be restored.
Link: https://lore.kernel.org/r/20210420061723.989-7-jianjun.wang@mediatek.com
Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Ryder Lee <ryder.lee@mediatek.com>
